Climate change issues, prevention, adaptation 7

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Climate change issues, prevention, adaptation 7

feb. 16, 2020, 7:51am

Edited extract from The Future We Choose: Surviving the Climate Crisis by Christiana Figueres and Tom Rivett-Carnac,
published by Manilla Press--no touchstones (yet?)

Christiana Figueres, author: ‘This is the decade and we are the generation


The only uncertainty is how long we’ll last’: a worst case scenario for the climate in 2050
Christiana Figueres and Tom Rivett-Carnac | Sat 15 Feb 2020

Air is cleaner than before the Industrial Revolution’: a best case scenario for the climate in 2050
Christiana Figueres and Tom Rivett-Carnac | Sat 15 Feb 2020

Editat: feb. 18, 2020, 6:11am

Jeff Bezos commits $10 billion to fight climate change
Rishi Iyengar | February 17, 2020

...a new fund to back scientists, activists and organizations working to mitigate the impact of climate change. Bezos will commit $10 billion "to start," he said in an Instagram post.

...the Bezos Earth Fund, will begin giving out grants this summer.

..."Climate change is the biggest threat to our planet," Bezos said in the post. "I want to work alongside others both to amplify known ways and to explore new ways of fighting the devastating impact of climate change."

...Bezos has been under pressure from his employees to do more to protect the environment

...A day before the walkout, Amazon announced a pledge to go carbon neutral by 2040, ten years before the deadline set out by the Paris climate agreement. The company also said it will deploy 100,000 electric delivery vans by 2024.

Amazon Employees for Climate Justice..."We applaud Jeff Bezos' philanthropy, but one hand cannot give what the other is taking away," the group said in a statement Monday, calling on Amazon to stop working with oil and gas companies or funding think tanks that deny climate change. "Will Jeff Bezos show us true leadership or will he continue to be complicit in the acceleration of the climate crisis, while supposedly trying to help?"

feb. 21, 2020, 9:35am

Climate Change to Increase Farmland and Environmental Threats: Study
Simran Chattha - February 19, 2020

...A new frontier that may increase farmland (almost 1/3 in the next 50-100 years) also poses environmental threats from degraded water quality and increased carbon emissions...

“Areas currently not suitable for agriculture are likely to become suitable in the next 50 to 100 years,” said Krishna Bahadur KC, an adjunct professor and research scientist with the Department of Geography, Environment and Geomatics at the University of Guelph.

...“As current lands become less suitable, there’s going to be pressure to develop new frontiers and that’s going to come with a host of major environmental consequences like releasing unprecedented amounts of carbon in the atmosphere, which then fuels additional climate change,” said Lee Hannah, a senior climate change scientist at Conservation International and lead author of the paper.

Published in PLOS One, the study combined projections for temperature and precipitation from 17 global climate models with agricultural models that predict suitability for growing 12 globally important food crops....


See figures at webpage .

Hannah L, Roehrdanz PR, K. C. KB, Fraser EDG, Donatti CI, Saenz L, et al. (2020) The environmental consequences of climate-driven agricultural frontiers. PLoS ONE 15(2): e0228305.

Growing conditions for crops such as coffee and wine grapes are shifting to track climate change. Research on these crop responses has focused principally on impacts to food production impacts, but evidence is emerging that they may have serious environmental consequences as well. Recent research has documented potential environmental impacts of shifting cropping patterns, including impacts on water, wildlife, pollinator interaction, carbon storage and nature conservation, on national to global scales. Multiple crops will be moving in response to shifting climatic suitability, and the cumulative environmental effects of these multi-crop shifts at global scales is not known. Here we model for the first time multiple major global commodity crop suitability changes due to climate change, to estimate the impacts of new crop suitability on water, biodiversity and carbon storage. Areas that become newly suitable for one or more crops are Climate-driven Agricultural Frontiers. These frontiers cover an area equivalent to over 30% of the current agricultural land on the planet and have major potential impacts on biodiversity in tropical mountains, on water resources downstream and on carbon storage in high latitude lands. Frontier soils contain up to 177 Gt of C, which might be subject to release, which is the equivalent of over a century of current United States CO2 emissions. Watersheds serving over 1.8 billion people would be impacted by the cultivation of the climate-driven frontiers. Frontiers intersect 19 global biodiversity hotspots and the habitat of 20% of all global restricted range birds. Sound planning and management of climate-driven agricultural frontiers can therefore help reduce globally significant impacts on people, ecosystems and the climate system.

feb. 21, 2020, 11:30am

Revealed: quarter of all tweets about climate crisis produced by bots
Oliver Milman | 21 Feb 2020

Draft of Brown study says findings suggest ‘substantial impact of mechanized bots in amplifying denialist messages’

...On an average day during the period studied, 25% of all tweets about the climate crisis came from bots. This proportion was higher in certain topics – bots were responsible for 38% of tweets about “fake science” and 28% of all tweets about the petroleum giant Exxon.

Conversely, tweets that could be categorized as online activism to support action on the climate crisis featured very few bots, at about 5% prevalence. The findings “suggest that bots are not just prevalent, but disproportionately so in topics that were supportive of Trump’s announcement or skeptical of climate science and action”, the analysis states.

Thomas Marlow, a PhD candidate at Brown who led the study, said the research came about as he and his colleagues are “always kind of wondering why there’s persistent levels of denial about something that the science is more or less settled on”.

The researchers examined 6.5m tweets posted in the days leading up to and the month after Trump announced the US exit from the Paris accords on 1 June 2017. The tweets were sorted into topic category, with an Indiana University tool called Botometer used to estimate the probability the user behind the tweet is a bot.

Marlow said he was surprised that bots were responsible for a quarter of climate tweets on an average day. “I was like, ‘Wow that seems really high,’” he said.

...some advocates of action to tackle the climate crisis are wary of a spike in activity around the US presidential election later this year.

“Even though we don’t know who they are, or their exact motives, it seems self-evident that Trump thrives on the positive reinforcement he receives from these bots and their makers,” said Ed Maibach, an expert in climate communication at George Mason University.

“It is terrifying to ponder the possibility that the Potus was cajoled by bots into committing an atrocity against humanity.”

feb. 22, 2020, 9:00am

Carbon Dioxide
January 2020
413 ppm

Carbon dioxide (CO2) is an important heat-trapping (greenhouse) gas, which is released through human activities such as deforestation and burning fossil fuels, as well as natural processes such as respiration and volcanic eruptions. The first graph shows atmospheric CO2 levels measured at Mauna Loa Observatory, Hawaii, in recent years, with average seasonal cycle removed. The second graph shows CO2 levels during the last three glacial cycles, as reconstructed from ice cores.

The time series below shows global distribution and variation of the concentration of mid-tropospheric carbon dioxide in parts per million (ppm). The overall color of the map shifts toward the red with advancing time due to the annual increase of CO2.

feb. 23, 2020, 3:21pm

Methane Emitted by Humans Vastly Underestimated – Powerful Greenhouse Gas Is Large Contributor to Global Warming
University of Rochester | February 22, 2020

...researchers...measured methane levels in ancient air samples and found that scientists have been vastly underestimating the amount of methane humans are emitting into the atmosphere via fossil fuels...reducing fossil fuel use is a key target in curbing climate change.

...By measuring the carbon-14 isotopes in air from more than 200 years ago, the researchers found that almost all of the methane emitted to the atmosphere was biological in nature until about 1870. That’s when the fossil component began to rise rapidly. The timing coincides with a sharp increase in the use of fossil fuels.

The levels of naturally released fossil methane are about 10 times lower than previous research reported. Given the total fossil emissions measured in the atmosphere today, Hmiel and his colleagues deduce that the manmade fossil component is higher than expected—25-40 percent higher, they found.

...if anthropogenic methane emissions make up a larger part of the total, reducing emissions from human activities like fossil fuel extraction and use will have a greater impact on curbing future global warming than scientists previously thought.


Benjamin Hmiel et al. 2020. Preindustrial 14CH4 indicates greater anthropogenic fossil CH4 emissions. Nature. 19 February 2020.
DOI: 10.1038/s41586-020-1991-8


Atmospheric methane (CH4) is a potent greenhouse gas, and its mole fraction has more than doubled since the preindustrial era. Fossil fuel extraction and use are among the largest anthropogenic sources of CH4 emissions, but the precise magnitude of these contributions is a subject of debate. Carbon-14 in CH4 (14CH4) can be used to distinguish between fossil (14C-free) CH4 emissions and contemporaneous biogenic sources; however, poorly constrained direct 14CH4 emissions from nuclear reactors have complicated this approach since the middle of the 20th century. Moreover, the partitioning of total fossil CH4 emissions (presently 172 to 195 teragrams CH4 per year) between anthropogenic and natural geological sources (such as seeps and mud volcanoes) is under debate; emission inventories suggest that the latter account for about 40 to 60 teragrams CH4 per year. Geological emissions were less than 15.4 teragrams CH4 per year at the end of the Pleistocene, about 11,600 years ago, but that period is an imperfect analogue for present-day emissions owing to the large terrestrial ice sheet cover, lower sea level and extensive permafrost. Here we use preindustrial-era ice core 14CH4 measurements to show that natural geological CH4 emissions to the atmosphere were about 1.6 teragrams CH4 per year, with a maximum of 5.4 teragrams CH4 per year (95 per cent confidence limit)—an order of magnitude lower than the currently used estimates. This result indicates that anthropogenic fossil CH4 emissions are underestimated by about 38 to 58 teragrams CH4 per year, or about 25 to 40 per cent of recent estimates. Our record highlights the human impact on the atmosphere and climate, provides a firm target for inventories of the global CH4 budget, and will help to inform strategies for targeted emission reductions.

feb. 24, 2020, 9:32am

'Antarctica Melts,' NASA Says, Showing Effects Of A Record Warm Spell
Bill Chappell | February 21, 20204:37 PM ET

Where there was a white ice cap, there are now brown blotches of land; melted snow and ice have created ponds of water....

(NASA's) photos center on Eagle Island, part of the northern tip of the Antarctic Peninsula that stretches toward South America. Satellites took the images just nine days apart, on Feb. 4 and Feb. 13. But dramatic changes took place in that time span. Two days after the first photo was taken, the area hit 18.3 degrees Celsius (64.9 degrees Fahrenheit) — matching that day's temperature in Los Angeles...

feb. 24, 2020, 4:36pm

A Security Threat Assessment of Global Climate Change: A Product of the National Security, Military and Intelligence Panel on Climate Change
Washington, DC, February 24, 2020

...In a comprehensive report released by the “National Security, Military and Intelligence Panel (NSMIP)” of the Center for Climate and Security, experts warn of High-to-Catastrophic threats to security from plausible climate change trajectories – the avoidance of which will require “quickly reducing and phasing out global greenhouse gas emissions.”

The panel, made up of national security, military and intelligence experts, analyzed the globe through the lens of the U.S. Geographic Combatant Commands, and concluded that:

“Even at scenarios of low warming, each region of the world will face severe risks to national and global security in the next three decades. Higher levels of warming will pose catastrophic, and likely irreversible, global security risks over the course of the 21st century.”

...Key findings

A near-term scenario of climate change, in which the world warms 1-2°C/1.8-3.6°F over pre-industrial levels by mid-century, would pose ‘High’ to ‘Very High’ security threats. A medium-to-long term scenario in which the world warms as high as 2-4+°C/3.6-7.2°F would pose a ‘Very High’ to ‘Catastrophic’ threat to global and national security. The world has already warmed to slightly below 1°C compared to pre-industrial temperatures.

At all levels of warming (1-4+°C/1.8-7.2+°F), climate change will pose significant and evolving threats to global security environments, infrastructure, and institutions.

While at lower warming thresholds, the most fragile parts of the world are the most at risk, all regions of the world will face serious implications. High warming scenarios could bring about catastrophic security impacts across the globe.

These threats could come about rapidly, destabilizing the regions and relationships on which U.S. and international security depend.

Climate change will present significant threats to U.S. military missions across all of its geographic areas of responsibility (AORs), as well as to regional security institutions and infrastructure that are critical for maintaining global security.

Key recommendations

Mitigating these risks requires quickly reducing and phasing out global greenhouse gas emissions. We call for the world to achieve net-zero global emissions as soon as possible in a manner that is ambitious, safe, equitable, and well-governed, in order to avoid severe and catastrophic security futures.

The world must also “climate-proof” environments, infrastructure, institutions, and systems on which human security depends, and so we call for rapidly building resilience to current and expected impacts of climate change. With future-oriented investments in adaptation, disaster response, and peacebuilding

In the United States, we call for renewed efforts to prioritize, communicate, and respond to climate security threats, and to integrate these considerations across all security planning.

...The climate security risks posed to each region of the world are assessed in the report through the lens of the U.S. Geographic Combatant Commands. Topline risks for each area of responsibility are summarized below.

AFRICOM Under a near-term, 1-2°C/1.8-3.6°F warming scenario, this region will likely see rapid loss of rural livelihoods, disease, resource stress, and migration. In this scenario, violent extremist groups bolster their numbers, and security threats spiral into nearby fragile areas.
Under a medium-to-long term, 2-4+°C/3.6-7.2+°F warming scenario, this region would experience new and renewed interstate conflict over water resources, and severe humanitarian crises resulting from migrating populations, weather disasters, and economic shocks. Security institutions may not be able to preserve stability in the region.

CENTCOM* Under a near-term, 1-2°C/1.8-3.6°F warming scenario, this region will likely experience dangerous levels of temperature rise, drought, and dwindling water supplies that intensify already tense resource, political, and territorial competition.
Under a medium-to-long term, 2-4+°C/3.6-7.2+°F warming scenario, this region would experience temperatures levels that render many areas of the region uninhabitable, competition over water resources, large-scale populations displacement, and social unrest leading to enduring conflicts and state failure.

EUCOM Under a near-term, 1-2°C/1.8-3.6°F warming scenario, this region will likely experience severe weather that threatens destabilization of its key economic sectors, rising regional inequality, migration and ethno-nationalist responses, and negative impacts on civil and military infrastructure.
Under a medium-to-long term, 2-4+°C/3.6-7.2+°F warming scenario, this region would experience prolonged drought and rising seas, significant internal displacement, and an influx of migrants from neighboring areas. A breakdown in regional political, institutional, and security cohesion becomes more likely.

INDOPACOM Under a near-term, 1-2°C/1.8-3.6°F warming scenario, this region will experience water scarcity in some areas and precipitation inundation in others, posing risks to security infrastructure, social stability, and tensions between regional powers.
Under a medium-to-long term, 2-4+°C/3.6-7.2+°F warming scenario, this region would experience devastating sea level rise threatening its megacities, infrastructure, and populations, and the resulting displacement and securitization of state borders.

NORTHCOM* Under a near-term, 1-2°C/1.8-3.6°F warming scenario, this region will experience more intense, extreme events like storms and wildfires, with significant impacts on life, property, security infrastructure, and democratic institutions.
Under a medium-to-long term, 2-4+°C/3.6-7.2+°F warming scenario, this region would experience extreme heat, sea level rise, and disaster events, with severe impact on critical and security infrastructure. The region would become increasingly divided, and potentially entangled in resource competitions.

SOUTHCOM* Under a near-term, 1-2°C/1.8-3.6°F warming scenario, this region will likely experience extreme heat and drought, forcing communities to migrate in search of new opportunities, with transnational criminal groups, and narcotics and human traffickers taking advantage of growing destabilization.
Under a medium-to-long term, 2-4+°C/3.6-7.2+°F warming scenario, this region would experience even more acute weather instability, crop collapse, and spreading disease. These issues, along with failing agriculture, will increase the likelihood of violent conflict, drive significant internal and cross-border migration, and increase political instability.

CENTCOM covers the "central" area of the globe located between the African, European and Indo-Pacific Commands
NORTHCOM continental United States, Puerto Rico, Canada, Mexico, The Bahamas, and the air, land and sea approaches to these areas. It is the U.S. military command which, if applicable, would be the primary defender against an invasion of the U.S.
SOUTHCOM Central and South America, the Caribbean (except U.S. commonwealths, territories, and possessions), incl. Panama Canal


Guy, Kate at al. “A Security Threat Assessment of Global Climate Change: How Likely Warming Scenarios Indicate a Catastrophic Security Future.” Product of the National Security, Military, and Intelligence Panel on Climate Change. Edited by Femia, Francecso. and Werrell, Caitlin. The Center for Climate and Security, an institute of the Council on Strategic Risks. Washington, DC. February 2020. 86 p.

feb. 26, 2020, 11:03am

Surface albedo effect: dark, open water absorbs more heat than reflective ice,
In addition, sounds like ~20% of Arctic warming is apparently due to Atlantic and Pacific feeding deeper waters in the Arctic,
with heat rising to waters under ice through the halocline, a strong, vertical salinity gradient that tends to isolate deep and surface waters.

(Wikipedia: Salt (in concert with temperature) affects the density of seawater, playing a role in its vertical stratification. (Low salinity water "swims" on top.) In certain high latitude regions (such as the Arctic Ocean, Bering Sea, and the Southern Ocean) the surface waters are colder than the deep waters and the halocline is responsible for maintaining water column stability, isolating the surface waters from the deep waters. In these regions, the halocline is important in allowing for the formation of sea ice, and limiting the escape of carbon dioxide to the atmosphere.)

Researchers find new reason Arctic is warming so fast
National Science Foundation | February 25, 2020

The Arctic has experienced the warming effects of global climate change faster than any other region on the planet. Scientists at the Scripps Institution of Oceanography have developed a new theory aided by computer simulations and observations that helps explain why this occurs.

...the water is warm at depth and cold near the surface. The deeper waters are fed by the relatively warm Pacific and Atlantic oceans, whereas the near-surface waters are in contact with sea ice and remain close to the freezing point. Heat flows upward from the warmer water to the colder water.

The scientists found that the deeper water is getting still warmer as a result of climate change, but the near-surface water below the sea ice remains close to the freezing point. The increasing difference in temperature leads to a greater upward flow of heat....estimate that this phenomenon is responsible for about 20% of the amplification of global warming that occurs in the Arctic....

E. Beer et al. 2020. Polar Amplification Due to Enhanced Heat Flux Across the Halocline. Geophysical Research Letters. First published: 03 February 2020

Polar amplification is a widely discussed phenomenon, and a range of mechanisms have been proposed to contribute to it, many of which involve atmospheric and surface processes. However, substantial questions remain regarding the role of ocean heat transport. Previous studies have found that ocean heat transport into the Arctic increases under global warming, but the reasons behind this remain unresolved. Here, we investigate changes in oceanic heat fluxes and associated impacts on polar amplification using an idealized ocean‐sea ice‐climate model of the Northern Hemisphere. We show that beneath the sea ice, vertical temperature gradients across the halocline increase as the ocean warms, since the surface mixed layer temperatures in ice‐covered regions are fixed near the freezing point. These enhanced vertical temperature gradients drive enhanced horizontal heat transport into the polar region and can contribute substantially to polar amplification.

Plain Language Summary
The Arctic region is warming at a faster rate than the rest of the globe. A number of mechanisms that may contribute to this have been identified, the most well‐known being the surface albedo feedback that occurs due to the higher reflectivity of ice compared to open water. However, substantial gaps remain in our understanding of what drives the polar amplification of global warming, and projections of how much the polar regions will warm in the future vary widely. Here, we look at the contribution to Arctic warming from the vertical transfer of heat in the upper ocean. In the Arctic Ocean, a large amount of heat is stored in relatively warm waters at depth, with a cold layer of water and sea ice cover above. The results indicate that the amount of heat from this warm water that reaches the sea ice cover will increase under global warming, enhancing the rate of warming in the Arctic region.

feb. 26, 2020, 11:10am

Goldman Sachs and now

JPMorgan Chase Will Halt Financing of Arctic Oil, Gas Drilling, Coal Plants
Garet Bleir | Feb 25 2020

In a major win for environmental organizations and Indigenous groups, JPMorgan Chase on Tuesday announced that it will not finance oil and gas extraction in the Arctic National Wildlife Refuge, nor will it continue financing many coal-related enterprises, including thermal coal mines and coal-fired power plants across the world. The announcement comes after a years-long pressure campaign by environmentalists and Indigenous peoples, who together have called on the giant bank—which is by far the leading US investor in fossil fuels—to move away from projects that threaten the climate.

JPMorgan Chase executives made the announcement at the bank’s annual Investor Day, during which they promised to stop investing in and providing services to companies that derive “the majority of their revenues from the extraction of coal” by 2024, as well as to not provide financing to offshore and onshore oil and gas extraction in the Arctic. JPMorgan Chase CFO Jennifer Piepszak also announced that the bank is committing $200 billion in financing across three focus areas: supporting climate action, clean water, and waste management; increasing access to housing, education, and health care; and advancing infrastructure, innovation, and growth.

Environmental activists and Indigenous leaders who have been staging protests against Chase applauded the announcement, which comes just two months after another leading US bank—Goldman Sachs—made a similar commitment not to finance oil drilling in the Arctic...

feb. 26, 2020, 2:38pm

The Coronavirus and Carbon Emissions

The coronavirus outbreak in China, which has sickened at least 77,000 people, has shut down factories, refineries and flights across the country as officials order people to stay home. As a result, China’s carbon dioxide emissions over the past three weeks have been about 25 percent lower than during the same period last year, according to calculations by Lauri Myllyvirta, an analyst at the Center for Research on Energy and Clean Air.

China is such a huge industrial polluter that even a temporary dip like this is significant: The three-week decline is roughly equal to the amount of carbon dioxide that the state of New York puts out in a full year (about 150 million metric tons) Mr. Myllyvirta estimated.

The effects have rippled through virtually all sectors of China’s economy.

Construction activity has slowed, which has meant reduced demand for steel and other materials. Oil refineries are producing less fuel than usual as cargo trucks sit idle and the number of flights has dropped by about 13,000 per day. Activity in key industrial sectors has declined by 15 percent to 40 percent over the last three weeks compared with the previous year.

But economic disruptions on this scale, whether caused by disease or recession, are usually accompanied by severe human costs and rarely make it easier to fight climate change. In some cases, they can make it harder.

For one thing, it’s likely that China’s emissions will quickly rebound when the outbreak is finally contained. Li Shuo, a senior policy adviser for Greenpeace Asia, said that in the past, China’s factories have tended to ramp up production to make up for lost output or temporary shutdowns, a practice he calls “retaliatory pollution.”

Mr. Li warned that the outbreak could even hinder China’s continuing efforts to green its economy and try to tackle climate change. The Chinese government has set ambitious targets for economic growth this year and will now have to race to make up for lost time.

feb. 27, 2020, 9:24am

This is mostly a fluff article from NPR, except for the last bit:

From Allergies To Declining Business, Warming Winters Affect Everyday Life

Heidi Steltzer is a mountain scientist and professor at Fort Lewis College in Durango, Colorado. She conducts snow experiments to determine how changing snowpack and snowmelt affect plants, water supply and people.

"Snow is magic in how it moves water into the Earth to sustain plants and people. It insulates the plants and ground. It radiates energy to the sky, keeping mountains wetter and cooler," Steltzer says.

Steltzer says that when warming brings temperatures above freezing, people see more rain than snow.

"Rain pours while snow seeps. Seeping is the magic ingredient for sustaining water supply," she says.

març 1, 2020, 6:05am

>12 2wonderY: Snow doesn't always seep unfortunately though I love the imagery for mountains!

Southeast of Lake Ontario (Tug Hill Plateau) suffered ~4 ft of lake-effect snow Thursday (little ice + polar vortex + strong winds), and now warm days, so floods...

Climate Change Pushes January 2020 to Hottest in 141 Years
Eric Roston | February 13, 2020

The year has started with the hottest January in the 141 years that global records have been kept, and it’s the biggest record-breaking margin—1.14° Celsius above the 20th century average—achieved without help from a warming El Niño event in the Pacific Ocean.

The new monthly record set by January 2020, according to data released Wednesday by the U.S. National Oceanic and Atmospheric Administration, continues an aggressive trend toward higher temperatures. The four hottest Januarys on record have all occurred since 2016, and the top-10 warmest have all occurred since 2002.

The new global record set by January 2020 comes just one week after the coldest continent, Antarctica, set high marks for warm temperatures. Argentine researchers measured 18.3° C on Feb. 6 , almost a full degree above the previous high set five years ago.

Last month marked the hottest January ever in Europe, according to the Copernicus Climate Change Service, with surface temperatures 3.1° C warmer than average. No region of the Earth’s land or ocean set cold records. Polar sea ice extent and Northern Hemisphere snowfall both finished January below average.

Editat: març 2, 2020, 5:35am

Why Milankovitch Cycles Can't Explain Earth's Current Warming
Alan Buis | February 27, 2020

In the last few months, a number of questions have come in asking if NASA has attributed Earth’s recent warming to changes in how Earth moves through space around the Sun: a series of orbital motions known as Milankovitch cycles.

...Milankovitch cycles include the shape of Earth’s orbit (its eccentricity), the angle that Earth’s axis is tilted with respect to Earth’s orbital plane (its obliquity), and the direction that Earth’s spin axis is pointed (its precession). These cycles affect the amount of sunlight and therefore, energy, that Earth absorbs from the Sun. They provide a strong framework for understanding long-term changes in Earth’s climate, including the beginning and end of Ice Ages throughout Earth’s history.

But Milankovitch cycles can’t explain all climate change that’s occurred over the past 2.5 million years or so. And more importantly, they cannot account for the current period of rapid warming Earth has experienced since the pre-Industrial period (the period between 1850 and 1900), and particularly since the mid-20th Century. Scientists are confident Earth’s recent warming is primarily due to human activities — specifically, the direct input of carbon into Earth’s atmosphere from burning fossil fuels.

...First, Milankovitch cycles operate on long time scales, ranging from tens of thousands to hundreds of thousands of years.

...Second, Milankovitch cycles are just one factor that may contribute to climate change, both past and present.

...Finally, Earth is currently in an interglacial period (a period of milder climate between Ice Ages). If there were no human influences on climate, scientists say Earth’s current orbital positions within the Milankovitch cycles predict our planet should be cooling, not warming, continuing a long-term cooling trend that began 6,000 years ago...


Milankovitch Cycles and Their Role in Earth's Climate
Alan Buis | February 27, 2020

març 2, 2020, 5:46am

Fire Fallout: How Ash and Debris Are Choking Australia’s Rivers
Adam Welz • February 27, 2020

The devastating bushfires that raged through southeastern Australia for months burned millions of acres. In the wake of the fires, a new threat has emerged – massive amounts of ash and debris being washed into rivers and waterways, killing fish and polluting water supplies.

...rapid decline in dissolved oxygen levels in the water

...large, dead fish that appeared to have asphyxiated, their gills blackened and clogged with ash. Some had red eyes and appeared to have been “cooked” in fire-heated water. Pulses of ash can cause rapid changes in pH, for example making usually acidic rivers extremely alkaline within a short time, with lethal impacts on river life, said Doyle.

...waterborne ash can have a number of effects on estuaries, including shading them and preventing phytoplankton growth, fertilizing them and promoting phytoplankton growth, and coating the estuary floor and organisms with fine sediment. Ash can contain toxic metals, and post-fire flooding can bring toxic fire retardants used in firefighting into estuaries.

...also affecting drinking water supplies...

març 5, 2020, 10:24am

Vox posted an informative slide show presentation :

These 3 supertrees can protect us from climate collapse

Featuring the Brazil nut tree in the Amazon, the stilt mangrove in Indonesia, and the African teak tree in the Congo.

Learned a lot!

Editat: març 6, 2020, 7:46am

Even if there was no climate issue the basic economics of solar panels —
considerable up-front costs to generate an ongoing stream of useful electricity with ~no continuing expense —
are a perfect match for very low long-term interest rates.
- Matthew Yglesias (Vox) @mattyglesias | 9:35 PM · Mar 5, 2020

Hey just FYI, we now have negative real interest rates on the 30 year treasury. So if you have any very long term public investments that might have any positive return, we should probably consider doing them.
Image ( )
- Neil Irwin (NYT) @Neil_Irwin | 9:32 PM · Mar 5, 2020


Far better to shade cars than farm fields, ponds and lakes:

My town of Lawrenceville , NJ has made two canopies of solar panels over the municipal building parking lot.
Creates shade for cars and generates electricity #WinWin
- Lynne Lyon @mamashizi11:56 PM · Mar 5, 2020

març 7, 2020, 3:20am

Mass melting of Antarctic ice sheet led to three metre sea level rise 120,000 years ago
Lisa Cox | 12 Feb 2020

Mass melting of the West Antarctic ice sheet, driven by warmer ocean temperatures, was a major cause of extreme sea level rise more than 100,000 years ago, according to new research.*

A research team, led by scientists at the University of New South Wales, examined the cause of high sea levels during a period known as the last interglacial, which occurred 129,000-116,000 years ago.

Their study finds that melting of the West Antarctic ice sheet caused a sea-level rise of more than three metres and it took less than 2C of ocean warming for that to occur...

...lead author Chris Turney...said the West Antarctic was particularly vulnerable to ocean warming because it sits mostly on the sea bed, rather than on land...


* Chris S. M. Turney et al. 2020. Early Last Interglacial ocean warming drove substantial ice mass loss from Antarctica.
PNAS February 25, 2020 117 (8) 3996-4006; first published February 11, 2020

Fifty years ago, it was speculated that the marine-based West Antarctic Ice Sheet is vulnerable to warming and may have melted in the past. Testing this hypothesis has proved challenging due to the difficulty of developing in situ records of ice sheet and environmental change spanning warm periods. We present a multiproxy record that implies loss of the West Antarctic Ice Sheet during the Last Interglacial (129,000 to 116,000 y ago), associated with ocean warming and the release of greenhouse gas methane from marine sediments. Our ice sheet modeling predicts that Antarctica may have contributed several meters to global sea level at this time, suggesting that this ice sheet lies close to a “tipping point” under projected warming.

The future response of the Antarctic ice sheet to rising temperatures remains highly uncertain. A useful period for assessing the sensitivity of Antarctica to warming is the Last Interglacial (LIG) (129 to 116 ky), which experienced warmer polar temperatures and higher global mean sea level (GMSL) (+6 to 9 m) relative to present day. LIG sea level cannot be fully explained by Greenland Ice Sheet melt (∼2 m), ocean thermal expansion, and melting mountain glaciers (∼1 m), suggesting substantial Antarctic mass loss was initiated by warming of Southern Ocean waters, resulting from a weakening Atlantic meridional overturning circulation in response to North Atlantic surface freshening. Here, we report a blue-ice record of ice sheet and environmental change from the Weddell Sea Embayment at the periphery of the marine-based West Antarctic Ice Sheet (WAIS), which is underlain by major methane hydrate reserves. Constrained by a widespread volcanic horizon and supported by ancient microbial DNA analyses, we provide evidence for substantial mass loss across the Weddell Sea Embayment during the LIG, most likely driven by ocean warming and associated with destabilization of subglacial hydrates. Ice sheet modeling supports this interpretation and suggests that millennial-scale warming of the Southern Ocean could have triggered a multimeter rise in global sea levels. Our data indicate that Antarctica is highly vulnerable to projected increases in ocean temperatures and may drive ice–climate feedbacks that further amplify warming.

març 17, 2020, 6:34am

Winter 2020 was the hottest on record without a super El Niño
Scott Sutherland | March 16th 2020

Winter 2020 is now the second warmest in the record books, according to NOAA, but it would rank even higher if it weren't for El Niño.

..."The second warmest December, warmest January, and second warmest February gave way to the second warmest December–February seasonal period in the 141-year record," the latest NOAA Global Climate Report for February 2020 reads. NOAA's climate records stretch back to 1879.

...According to the report, the global average surface temperature (across both land and ocean) for December-February was 1.12°C above the 20th century average of 15.6°C.

The only December-February period that had a higher temperature departure was December 2015 to February 2016, at +1.18°C. (a year with a super El Nino)....

març 22, 2020, 1:24am

Inside Clean Energy: Coronavirus May Mean Halt to Global Solar Gains—For Now
Revised forecasts indicate that demand for solar panels will be down this year for the first time since the 1980s.
Dan Gearino | Mar 19, 2020

...BloombergNEF has revised its global forecasts for 2020, saying that demand for photovoltaic solar panels will be in the range of 108 to 143 gigawatts, down from the range of 121 to 152 gigawatts that was in the forecast less than a month ago. This is an 8 percent decrease based on the midpoint of both ranges.

...Looking long-term, (Jenny Chase, Bloomberg NEF's lead solar analyst) thinks the pandemic will affect renewable energy in 2020 and have reverberations into some of 2021 before we get back to something resembling normal...

març 25, 2020, 3:03am

NASA images show ‘significant decreases’ in air pollution over China amid coronavirus economic slowdown—take a look
Cory Stieg | Mar 2 2020. Updated Fri, Mar 6 2020

març 31, 2020, 9:48am

Rare ozone hole opens over Arctic — and it’s big
Cold temperatures and a strong polar vortex allowed chemicals to gnaw away at the protective ozone layer in the north.
Alexandra Witze | 27 March 2020

A vast ozone hole — probably the biggest on record in the north — has opened in the skies above the Arctic. It rivals the better-known Antarctic ozone hole that forms in the southern hemisphere each year.

Record-low ozone levels currently stretch across much of the central Arctic, covering an area about three times the size of Greenland...The hole doesn’t threaten people’s health, and will probably break apart in the coming weeks. But it is an extraordinary atmospheric phenomenon that will go down in the record books.

“From my point of view, this is the first time you can speak about a real ozone hole in the Arctic,” says Martin Dameris, an atmospheric scientist at the German Aerospace Center in Oberpfaffenhofen.

...Is it dangerous?

Things would have been much worse this year if nations had not come together in 1987 to pass the Montreal Protocol, the international treaty that phases out the use of ozone-depleting chemicals...

The Arctic ozone hole isn’t a health threat because the Sun is just starting to rise above the horizon in high latitudes, says ( Markus Rex, an atmospheric scientist at the Alfred Wegener Institute in Potsdam, Germany ). In the coming weeks, there is a small chance the hole might drift to lower latitudes over more populated areas — in which case people might need to apply sunscreen to avoid sunburn...

...With the Sun slowly getting higher, atmospheric temperatures in the region of the ozone hole have already started to increase, says Antje Inness, an atmospheric scientist with the European Centre for Medium-Range Weather Forecasts in Reading, UK. Ozone could soon start to recover as the polar vortex breaks apart in the coming weeks.

abr. 1, 2020, 7:13am

Apparently, by making this change well before election, Administration minimizes opportunity for next President to reverse.

Trump’s mileage-standard rollback will cost consumers and the climate, say analysts
Rachel Koning Beals | March 31, 2020

...President Trump has passed the Corporate Average Fuel Economy, or CAFE, standards for new autos, a hard-fought regulatory battle that for now reduces targets on gas mileage and is expected to revive higher levels of emissions.

The rule change, softened from its initial language, had repeatedly been delayed and amended, in part due to a lukewarm response from an auto industry that had retooled for the tougher Obama-era regulations, adjusted to a mixed bag of state-by-state rules and was responding to a changing demographic of car and truck buyers who want a smaller carbon footprint. Both sides are bracing for expected court battles to challenge the rule change.

The Trump administration had long advocated for a reversal of the stance established during the Obama administration that had called for an unadjusted fleet average of 54.5 miles per gallon by 2025. Alternative-energy advocates believed the higher requirement would have helped promote a shift to electrified vehicles.

Trump wanted a full freeze on fuel-economy increases initially, but the final proposal reportedly settles on a 1.5% increase in efficiency for passenger cars and light trucks covering model years 2021 through 2026, pared from the current trajectory of 5%. Fuel efficiency in 2018 averaged 25.1 mpg in real-world driving (not just test driving), the Environmental Protection Agency said in a report issued in March. The fleet’s efficiency is preliminarily anticipated to have climbed to 25.5 mpg for the 2019 model year...

abr. 5, 2020, 6:18pm

Will Coronavirus Change How We Think About Climate Change?
David B. Green | Apr 04, 2020

Harvard historian Naomi Oreskes believes the coronavirus may be a 'dress rehearsal' for the climate catastrophe looming on the horizon – and suggests why people want to deny both threats

...In the United States climate-change deniers said they were defending freedom, defending democracy. The irony is, that, if this turns into a disaster situation, which it will if we continue the way we’re going, we’re going to lose our freedom, one way or the other. And it’s going to be the unfree countries, like China, who are going to be likely to survive… So, we in America will be in worse shape: We’ll lose both our freedom and our lives, whereas in China, they’ll just lose their freedom. And as you say, the pandemic is proving this...

abr. 5, 2020, 6:18pm

Will Coronavirus Change How We Think About Climate Change?
David B. Green | Apr 04, 2020

Harvard historian Naomi Oreskes believes the coronavirus may be a 'dress rehearsal' for the climate catastrophe looming on the horizon – and suggests why people want to deny both threats

...In the United States climate-change deniers said they were defending freedom, defending democracy. The irony is, that, if this turns into a disaster situation, which it will if we continue the way we’re going, we’re going to lose our freedom, one way or the other. And it’s going to be the unfree countries, like China, who are going to be likely to survive… So, we in America will be in worse shape: We’ll lose both our freedom and our lives, whereas in China, they’ll just lose their freedom. And as you say, the pandemic is proving this...

abr. 6, 2020, 8:09am

Children of the Crisis
Alex Morris | March 27, 2020

A generation of kids faces a more dangerous world as they come of age in the era of eco-anxiety

Editat: abr. 11, 2020, 5:06am

Meanwhile, we haven't come close to bending the CO2 accumulation curve.
- Anthony Ricciardi @EcoInvasions | 7:42 PM · Apr 10, 2020

*416.78 parts per million (ppm) CO2 in air 09-Apr-2020

Ralph Keeling: "The recent all-time daily record at Mauna Loa is in line with jumps we've seen around this time in previous years.
CO2 levels rise every year from March through April
as part of the normal seasonal trend which usually achieves a seasonal peak in May...." 1/2

"...This week’s new highs are daily fluctuations on top of this seasonal cycle.
Each year we set new record highs due to continuing fossil fuel emissions, which raise the baseline every year.
The changes in emissions from #COVID-19 are not large enough to break this pattern." 2/2

- Keeling_Curve @Keeling_curve (April 10, 2020)

abr. 14, 2020, 8:44am

Abrupt exposure events begin before 2030 in tropical oceans and spread to tropical forests and higher latitudes by 2050.

Less than 2% of assemblages globally are projected to undergo abrupt exposure events of more than 20% of their constituent species if global warming is kept below 2 °C; 15% of assemblages are threatened at 4 °C, with similar levels of risk in protected and unprotected areas.


Christopher H. Trisos et al. 2020. The projected timing of abrupt ecological disruption from climate change.
Nature (April 8, 2020)

As anthropogenic climate change continues the risks to biodiversity will increase over time, with future projections indicating that a potentially catastrophic loss of global biodiversity is on the horizon. However, our understanding of when and how abruptly this climate-driven disruption of biodiversity will occur is limited because biodiversity forecasts typically focus on individual snapshots of the future. Here we use annual projections (from 1850 to 2100) of temperature and precipitation across the ranges of more than 30,000 marine and terrestrial species to estimate the timing of their exposure to potentially dangerous climate conditions. We project that future disruption of ecological assemblages as a result of climate change will be abrupt, because within any given ecological assemblage the exposure of most species to climate conditions beyond their realized niche limits occurs almost simultaneously. Under a high-emissions scenario (representative concentration pathway (RCP) 8.5), such abrupt exposure events begin before 2030 in tropical oceans and spread to tropical forests and higher latitudes by 2050. If global warming is kept below 2 °C, less than 2% of assemblages globally are projected to undergo abrupt exposure events of more than 20% of their constituent species; however, the risk accelerates with the magnitude of warming, threatening 15% of assemblages at 4 °C, with similar levels of risk in protected and unprotected areas. These results highlight the impending risk of sudden and severe biodiversity losses from climate change and provide a framework for predicting both when and where these events may occur.

abr. 17, 2020, 8:01am

Yay! But what a price to pay...

Carbon emissions from fossil fuels could fall by 2.5bn tonnes in 2020
Reduction of 5% would represent biggest drop in demand for industry on record
Jillian Ambrose | Sun 12 Apr 2020

Analysts expect a slump in heavy industry to drive demand for gas and coal down by about 2.3% each.

Global carbon emissions from the fossil fuel industry could fall by a record 2.5bn tonnes this year, a reduction of 5%, as the coronavirus pandemic triggers the biggest drop in demand for fossil fuels on record.

The unprecedented restrictions on travel, work and industry due to the coronavirus is expected to cut billions of barrels of oil, trillions of cubic metres of gas and millions of tonnes of coal from the global energy system in 2020 alone.

...Erik Holm Reiso, a senior partner at (Rystad Energy, a Norwegian energy consultancy), said: “The coronavirus pandemic is an unprecedented event for energy markets, which will have a substantial impact on the world’s total carbon emissions...The last time demand for oil contracted, during the financial crisis in 2008 to 2009, demand fell by 1.3m barrels of oil a day. But Covid-19 could cause oil demand to fall by more than five times as much.”

The unprecedented drop in oil demand will emerge in large part due the global aviation industry, he said. Typically there are about 99,700 commercial flights per day but the crackdown on non-essential travel to curb the spread of the virus could see air traffic fall by an average of almost a quarter over the year.

Fewer cars on the road will also dent demand for petrol and diesel by an average of 9.4% over the year, shrinking oil demand in 2020 by an average of 2.6m barrels of oil a day.

Editat: abr. 19, 2020, 8:16am

How can (travel) be sustainable post-Covid 19?
Chloe Berge | 16 April 2020

...when the world stays home, the planet benefits.

...Restrictions on non-essential travel means airlines are grounding planes, drastically slashing flights or suspending operations completely.

...there are three personal choices we can make to quickly cut a lot of greenhouse gas emissions: reduce air and car travel, as well as meat consumption.

...emissions from tourism add up to 8% of the global total, with flying making up the largest share of this...Kimberly Nicholas, a sustainability scientist at LUCSUS... “One round-trip flight from New York to London is the equivalent of about two years of eating meat in terms of personal carbon footprint.”

...when we can travel again, should we?

...Some airlines are making headway through research into innovations like biofuel and electric-powered aircraft. “There's still a lot of potential fuel economy that could be gained from redesigning aircraft to be more efficient,” said Colin Murphy, deputy director of The Policy Institute for Energy, Environment and the Economy at University of California, Davis. “If you're using waste oil, biofuels typically get about 60% greenhouse gas reductions compared to conventional petroleum,” he added. The amount of land needed to grow new sources of biofuel – renewable fuel derived from organic materials – could pose a problem, however. And while there’s potential for electric-powered aircraft, Murphy notes that limited battery technology means this will never be a viable solution for long-haul flights.

Overtourism is just another form of overconsumption

...Just as the planet seems to be taking a breath right now, we’ve also been offered an opportunity for introspection. The coronavirus pandemic has forced us to see how interconnected the people, systems and organisations in our world’s also shown us how we’re able to unite and act as individuals for the collective good.

...we should consider a slower, more thoughtful approach to travel. There’s an authentic connection that comes with a place when we take the time to understand its people, culture and natural beauty in a meaningful way. This can’t be achieved with superficial port-to-port itineraries – we could also do without the environmental wreckage that a lot of large cruise ships leave in their wake – or by hopping around to a legion of countries in two weeks. It might mean taking one longer trip per year instead of packing in five or six shorter ones, which would drastically reduce our carbon footprint.

...keep....more of our adventures local...his might look like enjoying your local beach instead of one in Mexico and saving your carbon budget for a more impactful trip.

When we do fly, we can purchase carbon offsets.

How we fly also matters...“The more densely packed you are, the lower your emissions are per passenger mile by quite a bit,” Murphy notes. “At a policy level, we need transparency about the true environmental impact of our choices, and we need prices to align with those impacts,” said Austin Brown, executive director of the Policy Institute at UC Davis.

When we’re on the ground in a destination, we can reduce our footprint by being respectful to the area’s culture and environment...choose sustainable accommodation and activities, and a green mode of transportation to explore the place you’re in.

There are destinations, worldwide, reliant on travel and tourism for survival

...Outside of the global tourism economy, travel has the potential to benefit all of us. When we travel in a meaningful way, we gain cross-cultural understanding and develop greater empathy for people outside of our immediate circle. Travel gives us the global perspective we need to care about the future of our home here on Earth.

...Our ability to wander has been temporarily taken from us, and never has it felt like more of a luxury. “This crisis might give us the opportunity to instill a new travel mindset,” said (Shannon Stowell, CEO of the Adventure Travel Trade Association and sustainable travel advocate). “Travel is a privilege, not a right.”

I can’t imagine a world without travel, but I know that if we don’t change how we travel, there won’t be a planet left for us to explore.

abr. 19, 2020, 8:24am

Think This Pandemic Is Bad? We Have Another Crisis Coming
Addressing climate change is a big enough idea to revive the economy.
Rhiana Gunn-Wright | April 15, 2020

...Of the nearly $2 trillion in aid proposed in that first version of the Coronavirus Aid, Relief, and Economic Security Act, known as the CARES Act, $500 billion went toward a business-relief fund with little to no oversight. Fifty-eight billion of this was earmarked for airlines, and a lax definition of eligible businesses created a loophole for oil and gas. The bill included no climate protections...And the changes proposed by Democrats — emissions reductions for airlines, limiting bailouts for fossil fuel industries, protections for airline workers — were modest.

...the airlines had requested $50 billion after spending $45 billion on stock buybacks over the past five years.

...If history is any indication, rebounding from an economic disruption this large requires an equally large spike in demand and production. Outside of war, climate change is the only issue large enough to provide such a spike. Now is the time to create policies that provide immediate relief to communities, such as federal assistance to transition homes and businesses to renewable energy; give “green” fiscal aid to states; and fuel economic recovery with the creation of federally funded green jobs. But none of this can happen so long as our leaders keep convincing themselves that the greatest country in the world cannot walk and chew gum at the same time.

A climate-focused economic recovery — much less a coronavirus response that acknowledges the climate crisis — could require a new Congress and a new president, a tall order in an America this divided. But maybe it is time to stop acting as though politics is a force of nature when we are facing actual and deadly forces of nature. It’s past time to elect leaders who are fit to handle the crises we face, instead of hoping for problems small enough to fit the leaders we have...

abr. 21, 2020, 4:55pm

We Could Release Herds of Animals in The Arctic to Fight Climate Change, Says Study

Herds of horses, bison and reindeer could play a significant part in saving the world from an acceleration in global heating. That is the conclusion of a recent study showing how grazing herbivores can slow down the pace of thawing permafrost in the Arctic.

The study* - a computerized simulation based on real-life, on-the ground data - finds that with enough animals, 80 percent of all permafrost soils around the globe could be preserved through 2100.

The research was inspired by an experiment in the town of Chersky, Siberia featured on CBS News' 60 Minutes. The episode introduces viewers to an eccentric scientist named Sergey Zimov who resettled grazing animals to a piece of the Arctic tundra more than 20 years ago.

Zimov is unconventional, to say the least, even urging geneticists to work on resurrecting a version of the now-extinct woolly mammoth to aid in his quest. But through the years he and his son Nikita have observed positive impacts from adding grazing animals to the permafrost area he named Pleistocene Park, in a nod to the last ice age...

Christian Beer et al. 2020. Protection of Permafrost Soils from Thawing by Increasing Herbivore Density. Scientific Reports volume 10, Article number: 4170 (17 March 2020)

Climate change will cause a substantial future greenhouse gas release from warming and thawing permafrost-affected soils to the atmosphere enabling a positive feedback mechanism. Increasing the population density of big herbivores in northern high-latitude ecosystems will increase snow density and hence decrease the insulation strength of snow during winter. As a consequence, theoretically 80% of current permafrost-affected soils (

abr. 21, 2020, 5:23pm

Southwest Drought Could Be Worst in 1,200 Years, Due to the Climate Crisis
Jordan Davidson | Apr. 17, 2020

A severe drought that has engulfed the American Southwest since the year 2000 is likely to soon be the most severe drought since the 800s, according to a new study published in Science.*

"This appears to be just the beginning of a more extreme trend toward megadrought...

* A. Park Williams et al. 2020. Large contribution from anthropogenic warming to an emerging North American megadrought. Science 17 Apr 2020: Vol. 368, Issue 6488, pp. 314-318 DOI: 10.1126/science.aaz9600

A trend of warming and drying
Global warming has pushed what would have been a moderate drought in southwestern North America into megadrought territory. Williams et al. used a combination of hydrological modeling and tree-ring reconstructions of summer soil moisture to show that the period from 2000 to 2018 was the driest 19-year span since the late 1500s and the second driest since 800 CE (see the Perspective by Stahle**). This appears to be just the beginning of a more extreme trend toward megadrought as global warming continues.

Severe and persistent 21st-century drought in southwestern North America (SWNA) motivates comparisons to medieval megadroughts and questions about the role of anthropogenic climate change. We use hydrological modeling and new 1200-year tree-ring reconstructions of summer soil moisture to demonstrate that the 2000–2018 SWNA drought was the second driest 19-year period since 800 CE, exceeded only by a late-1500s megadrought. The megadrought-like trajectory of 2000–2018 soil moisture was driven by natural variability superimposed on drying due to anthropogenic warming. Anthropogenic trends in temperature, relative humidity, and precipitation estimated from 31 climate models account for 47% (model interquartiles of 35 to 105%) of the 2000–2018 drought severity, pushing an otherwise moderate drought onto a trajectory comparable to the worst SWNA megadroughts since 800 CE.

** David W. Stahle. 2020. Anthropogenic megadrought. Science 17 Apr 2020: Vol. 368, Issue 6488, pp. 238-239
DOI: 10.1126/science.abb6902

Historical documents from the Spanish Entrada on the northern frontier of New Spain (now the U.S. Southwest) include anecdotal evidence for unusual aridity in the late 16th century (1). However, a quantitative record of the 16th-century megadrought has only recently been obtained from hundreds of exactly dated and moisture-sensitive tree-ring chronologies developed across Canada, the United States, and Mexico. On page 314 of this issue, Williams et al. (2) provide a new assessment of proxy climate data from the U.S. Southwest. They determine that the 16th-century megadrought was the worst multidecadal drought episode in the Southwest over the past 1200 years, and that the second-worst event occurred from 2000 to 2018 over southwestern North America (SWNA) and may be ongoing. The study also pinpoints substantial anthropogenic (human) contribution to the severity of the current drought.

abr. 22, 2020, 9:07am

Webinar: Corporate Knights Presents: Recovering Stronger with a Green Renovation Wave.

Join us on Wednesday, Apr 22, 2020 11:00 AM in Eastern Time (US and Canada) to see fresh analysis showing how a post-COVID green renovation wave could help our economy come roaring back, along with reactions from panelists and expert commentators.

Welcome from Hon. Jonathan Wilkinson, Minister of Environment and Climate Change (TBC)

Discussion Hosted by Diana Fox Carney, Economist and Public Policy Expert

• Derek Ballantyne, Board Chair, Canada Mortgage and Housing Corporation
• Stewart Elgie, Executive Chair, Smart Prosperity Institute
• Jonathan Hackett, Head of Sustainable Finance, BMO Financial Group
• Gord Hicks, CEO, BGIS (Chair, Building Energy Innovator’s Council)
• Julia Langer, CEO, The Atmospheric Fund
• Thomas Mueller, CEO, Canadian Green Building Council

Expert Commentators
• Céline Bak, Founder and President, Analytica Advisors
• Andy Chisholm, Board Member, RBC
• Corey Diamond, Executive Director, Energy Efficiency Canada
• Terri Lynn Morrison, Director of Strategic Partnership, Indigenous Clean Energy (ICE)
• Angela MacEwan, CUPE Senior Economist and Broadbent Institute Fellow
• Sean Mullin, Executive Director and Co-Founder, Brookfield Institute for Innovation + Entrepreneurship
• Dave Sawyer, Chief Economist, Canadian Institute for Climate Choices
• Steven Tobin, Executive Director, Labour Market Information Council
• Ralph Torrie, Senior Associate, Sustainability Solutions Group and Partner, Torrie Smith Associates

abr. 24, 2020, 7:49am

How Is the Coronavirus Pandemic Affecting Climate Change?
Sure, emissions have fallen. But a closer look at how the global crisis is influencing the environment reveals some surprising dynamics.
Matt Simon | 04.21.2020

(1) Yes, Emissions Are Falling. But Not for Long

as the pandemic seized hold of China’s economy and heavy industries shuttered, emissions from the country plummeted by an incredible 25 percent...globally this year, emissions could fall by 5.5 percent from 2019 levels...The 5.5 percent figure tops the 3 percent reduction in emissions that followed the 2008 financial crash, when economies also slowed and people traveled less. But emissions bounced right back as the economy recovered...

(2) Electricity Use in the US Has Declined Slightly, But Gasoline Sales Dropped Big Time

...The amount of gasoline supplied in the US—a close measurement of direct consumption—fell by 50 percent over the two-week period ending April 3...the amount of diesel supplied has remained fairly stable...more of a commercial fuel, used for the semi trucks that are still making deliveries...

Electricity use across the country has declined a bit, but nowhere near as dramatically as with fuel supplies....commercial buildings...home...China’s (25 percent reduction) emissions earlier this year...uses massive amounts of energy to keep production running. But the US and many other nations have offshored much of their manufacturing and transitioned into being service economies. When China’s workers go home, those emission-heavy industries close down. When workers in some other nations go home, they keep working, shifting the energy consumption from offices to houses.

(3) This Is Our Chance to Reinvent Cities

We’re getting a taste of how much more livable our cities would be if we designed them for people, not cars.

(4) In a Weird Way, Some Air Pollution Actually Reduces Warming

...air pollution: It can actually bounce the sun’s energy back into space, thus helping cool the planet....sulfate particles attract water vapor, making a cloud brighter, and therefore better able to reflect general, pollution-seeded clouds block 1 watt of energy per square meter of planet Earth. For comparison, anthropogenic greenhouse-gas emissions trap 3 watts per square meter....

To be clear: Air pollution is a major threat to human health. The carbon monoxide cars spew is toxic, and CO2 has led to runaway global warming. But in a bizarre way, this specific type of emission seems to help cool the planet. (margd: Ship emissions cause more lightning over shipping lanes: All NO2 and SO2 emissions contribute to acid rain. )

(5) Cheap Oil Means the Pandemic Is Producing Mountains of Plastic Waste

...Given the low price of oil in recent years, it’s often cheaper for companies to buy virgin plastic bottles than recycled ones...many recycling facilities are shutting down to protect their workers...we’re consuming more single-use plastic than ever....soap and hand sanitizer...individually wrapped products...plastic-sheathed takeout from restaurants...

(6) Every Nation Needs a Big, Bold, New Green Deal

...For an economically developing country in particular, the allure of fossil fuels is they allow rapid industrialization. Renewable energies like solar wind are still relatively expensive to set up compared with coal and natural gas, which is why governments usually subsidize them to green their economies...

... (Trump unlikely to subsidize green energy to re-invigorate the economy but) if the feds keep interest rates low to make borrowing easier and jump-start the economy, it’ll be easier to finance a wind farm or solar facility...oil, which is now even cheaper thanks to the pandemic.

(7) Climate Research in the Coronavirus Age

Scientists, they’re just like us—in the sense that they too are stuck at home during the pandemic. And that’s a big problem for climate science....

If you can’t get on a boat, you can’t collect data on how the oceans are warming and acidifying. Scientists who monitor the effects of climate change on wildlife can’t go out and collect photos from camera traps. Conserving species imperiled by climate change isn’t a passive process—conservationists have to be out there actively monitoring and preserving their habitats. If you study how permafrost is thawing in the Arctic, you’re out of luck as well. Even if a scientist can collect data remotely, for instance by aggregating government data, they may not have access to the requisite computing power at home.

“There will probably be a record gap that’ll be a problem, and if it goes on long enough it’ll be a real problem,” says Gurney. “A few weeks, you could say 'Well, we might be able to deal with that.' But if it turns into months, that becomes a significant problem for anybody who has to go out in the field.”

abr. 25, 2020, 7:13am

The world’s biggest ecosystem restoration project
UN | 23 Apr 2020

...In the post COVID-19 era, restoring degraded drylands across vast swathes of Africa could make a major contribution towards creating a healthier planet with healthier ecosystems.

The Great Green Wall is an African-led movement of epic proportions initiated in 2007 to green the entire width of Africa, a very dry region extending from Senegal to Djibouti.

The focus has since shifted to a more integrated approach including sustainable land use, livelihood and job creation, and peacebuilding.

Landscape degradation, climate change and rapidly increasing populations over the past 50 years are often major drivers of conflict. The Great Green Wall aims to bring people together, restore degraded land and promote sustainable development. It’s no longer simply about planting trees.

The Food and Agriculture Organization of the United Nations (FAO) has estimated that the core area of the Great Green Wall for the Sahara and the Sahel stands at 780 million hectares (more than two times bigger than India), 21 per cent of which includes restorable agro-sylvo-pastoral lands. Of this total, the United Nations and Member States agreed in September 2019 to restore 100 million hectares by 2030.

The Great Green Wall contributes to, or directly supports, 10 of the 17 Sustainable Development Goals, and has been endorsed by over 20 countries...

abr. 30, 2020, 10:51am

The world is on lockdown. So where are all the carbon emissions coming from?
Shannon Osaka | Apr 27, 2020

...A 5.5-percent drop in carbon dioxide emissions would still be the largest yearly change on record, beating out the financial crisis of 2008 and World War II. But it’s worth wondering: Where do all of those emissions come from? And if stopping most travel and transport isn’t enough to slow down climate change, what will be?

Transportation makes up a little over 20 percent of global carbon dioxide emissions...In the United States, it makes up around 28 percent....

So where are all those emissions coming from? For one thing, utilities are still generating roughly the same amount of electricity — even if more of it’s going to houses instead of workplaces. Electricity and heating combined account for over 40 percent of global emissions. Many people around the world rely on wood, coal, and natural gas to keep their homes warm and cook their food — and in most places, electricity isn’t so green either.

Even with a bigger proportion of the world working from home, people still need the grid to keep the lights on and connect to the internet. ...

Manufacturing, construction, and other types of industry account for approximately 20 percent of CO2 emissions. Certain industrial processes like steel production and aluminum smelting use huge amounts of fossil fuels — and so far, (Gavin Schmidt, a climatologist and the director of the NASA Goddard Institute for Space Studies in New York City) says, that type of production has mostly continued despite the pandemic.

The reality is that emissions need to be cut by 7.6 percent every year to keep global warming from surpassing 1.5 degrees Celsius above pre-industrial levels...Even if the global lockdown and economic slump reduce emissions by 7.6 percent this year, emissions would have to fall even more the year after that. And the year after that. And so on.

...Carbon dioxide is invisible, and power plants and oil refineries are still pumping it into the atmosphere. Meanwhile, natural gas companies and livestock farming (think cow burps) keep releasing methane.

...2020 is already on track to be the warmest ever recorded, beating out 2016. In a sad irony, the decrease in air pollution may make it even hotter. Veerabhadran Ramanathan, a professor at the Scripps Institution of Oceanography at University of California, San Diego, explained that many polluting particles have a “masking” effect on global warming, reflecting the sun’s rays, canceling out some of the warming from greenhouse gas emissions...

Editat: maig 4, 2020, 1:03pm

>36 margd: 'restoring degraded drylands across vast swathes of Africa" , Sounds like a great project.

Made me think of the idea I had when I first saw the, 60 Minutes?, show about the the geologic plate rift opening up in Africa. I remember there were shots of the canyon areas being produced along the slowly growing rift and, most interesting to me, a small waterfall of sea water flowing into a rift area from the Red Sea. I thought of an geo engineering idea to make a bigger path from the Red Sea to the rift and have an inland sea which would evaporate to produce rain clouds? Of course huge variables as to what would actually happen,.

Addendum:: Well I looked up so more info on the area and found out they have monsoon weather {80 " year?} around the fault area so maybe any moisture impact would be negligible. But the geological happenings are amazing.

maig 5, 2020, 6:00am

Yes! (the geological happenings are amazing)

Global warming to push billions outside climate range that has sustained society for 6,000 years, study finds
Andrew Freedman | May 4 at 3:00 PM

...humans have a particular climate niche, scientists have found, with 6,000 years of human history demonstrating how society thrives when we stay within it and the turbulence that ensues when it is pushed out of this zone.

In a stark new finding about the planet’s rapidly warming climate, a study finds that for every 1.8 degrees Fahrenheit (1 degree Celsius) of global average warming, 1 billion people will have to adapt or migrate to stay within climate conditions that are best suited for crop production, livestock and a sustainable outdoor work environment.*

The study, published in the Proceedings of the National Academy of Sciences on Monday, breaks new ground by quantifying the temperature range society is most adapted to and projecting how climate change will push people outside it....

See map at


* Chi Xu et al. 2020. Future of the human climate niche. PNAS first published May 4, 2020

We show that for thousands of years, humans have concentrated in a surprisingly narrow subset of Earth’s available climates, characterized by mean annual temperatures around ∼13 °C. This distribution likely reflects a human temperature niche related to fundamental constraints. We demonstrate that depending on scenarios of population growth and warming, over the coming 50 y, 1 to 3 billion people are projected to be left outside the climate conditions that have served humanity well over the past 6,000 y. Absent climate mitigation or migration, a substantial part of humanity will be exposed to mean annual temperatures warmer than nearly anywhere today.

All species have an environmental niche, and despite technological advances, humans are unlikely to be an exception. Here, we demonstrate that for millennia, human populations have resided in the same narrow part of the climatic envelope available on the globe, characterized by a major mode around ∼11 °C to 15 °C mean annual temperature (MAT). Supporting the fundamental nature of this temperature niche, current production of crops and livestock is largely limited to the same conditions, and the same optimum has been found for agricultural and nonagricultural economic output of countries through analyses of year-to-year variation. We show that in a business-as-usual climate change scenario, the geographical position of this temperature niche is projected to shift more over the coming 50 y than it has moved since 6000 BP. Populations will not simply track the shifting climate, as adaptation in situ may address some of the challenges, and many other factors affect decisions to migrate. Nevertheless, in the absence of migration, one third of the global population is projected to experience a MAT >29 margd: °C currently found in only 0.8% of the Earth’s land surface, mostly concentrated in the Sahara. As the potentially most affected regions are among the poorest in the world, where adaptive capacity is low, enhancing human development in those areas should be a priority alongside climate mitigation.

maig 7, 2020, 4:20am

Cold air rises—what that means for Earth's climate
UC Davis | May 6, 2020

Conventional knowledge has it that warm air rises while cold air sinks. But a study from the University of California, Davis, found that in the tropical atmosphere, cold air rises due to an overlooked effect—the lightness of water vapor. This effect helps to stabilize tropical climates and buffer some of the impacts of a warming climate.

The study, published today in the journal Science Advances, is among the first to show the profound implications water vapor buoyancy has on Earth's climate and energy balance.*

...The study found that the lightness of water vapor increases Earth's thermal emission by about 1-3 watts per square meter over the tropics. That value compares with the amount of energy captured by doubling carbon dioxide in the atmosphere. The authors' calculations further suggest that the radiative effects of vapor buoyancy increase exponentially with climate warming...


* Seth D. Seidel and Da Yang. 2020. The lightness of water vapor helps to stabilize tropical climate. Science Advances 06 May 2020: Vol. 6, no. 19, eaba1951
DOI: 10.1126/sciadv.aba1951

Moist air is lighter than dry air at the same temperature, pressure, and volume because the molecular weight of water is less than that of dry air. We call this the vapor buoyancy effect. Although this effect is well documented, its impact on Earth’s climate has been overlooked. Here, we show that the lightness of water vapor helps to stabilize tropical climate by increasing the outgoing longwave radiation (OLR). In the tropical atmosphere, buoyancy is horizontally uniform. Then, the vapor buoyancy in the moist regions must be balanced by warmer temperatures in the dry regions of the tropical atmosphere. These higher temperatures increase tropical OLR. This radiative effect increases with warming, leading to a negative climate feedback. At a near present-day surface temperature, vapor buoyancy is responsible for a radiative effect of 1 W/m2 and a negative climate feedback of about 0.15 W/m2 per kelvin.

maig 7, 2020, 4:24am

Pakistan turns unemployed workers into tree planters
Katherine Martinko | May 4, 2020

...In 2018, Pakistan pledged to plant ten billion trees in an effort to slow climate change and to replenish a landscape that has been decimated by decades of deforestation, livestock grazing, and drought. It was an ambitious goal, but as the Washington Post reported at the time, "the idea of a green awakening seems to be taking root... The concept appeals to a new generation of better-educated Pakistanis, and it has sparked excitement on social media."

That program, whose name is 10 Billion Tree Tsunami, has been chugging along for the past two years, but it recently received an unexpected infusion of help from – of all things – the coronavirus. Many Pakistanis are suddenly unemployed, so the government has given them jobs as tree-planters. Unemployed day laborers have been turned into "jungle workers," planting saplings for 500 rupees a day ($3), which is roughly half of what a construction worker would normally earn. It's not a lot, but it's enough to get by, and that can mean the difference between survival and starvation....

maig 8, 2020, 6:51am

The best trees to reduce air pollution
Vittoria Traverso | 4th May 2020


Yendle Barwise & Prashant Kumar. 2020. Designing vegetation barriers for urban air pollution abatement: a practical review for appropriate plant species selection. npk Climate and Atmospheric Science volume 3, Article number: 12 (2020)

Vegetation can form a barrier between traffic emissions and adjacent areas, but the optimal configuration and plant composition of such green infrastructure (GI) are currently unclear. We examined the literature on aspects of GI that influence ambient air quality, with a particular focus on vegetation barriers in open-road environments. Findings were critically evaluated in order to identify principles for effective barrier design, and recommendations regarding plant selection were established with reference to relevant spatial scales. As an initial investigation into viable species for UK urban GI, we compiled data on 12 influential traits for 61 tree species, and created a supplementary plant selection framework. We found that if the scale of the intervention, the context and conditions of the site and the target air pollutant type are appreciated, the selection of plants that exhibit certain biophysical traits can enhance air pollution mitigation. For super-micrometre particles, advantageous leaf micromorphological traits include the presence of trichomes and ridges or grooves. Stomatal characteristics are more significant for sub-micrometre particle and gaseous pollutant uptake, although we found a comparative dearth of studies into such pollutants. Generally advantageous macromorphological traits include small leaf size and high leaf complexity, but optimal vegetation height, form and density depend on planting configuration with respect to the immediate physical environment. Biogenic volatile organic compound and pollen emissions can be minimised by appropriate species selection, although their significance varies with scale and context. While this review assembled evidence-based recommendations for practitioners, several important areas for future research were identified.

maig 9, 2020, 7:56am

‘Steambath Earth’: Unsurvivable heat and humidity extremes have emerged earlier than expected, study finds
Andrew Freedman, Jason Samenow

...wet bulb temperatures of 95 degrees (35 Celsius), which renders ineffective the human heat response of sweating to shed heat through evaporation, leading to hyperthermia, are already occurring for short periods of time at a few weather stations.

These tend to be located in parts of the Persian Gulf shoreline and coastal southwest North America, where sizzling lands border sultry seas, as well as in northern South Asia, where extreme heat and humidity combinations overlap just before the annual monsoon begins.

With computer model projections showing the world will continue to warm rapidly in response to increasing amounts of greenhouse gases in the atmosphere, the study...warns that highly populated regions of the world will be rendered uninhabitable sooner than previously thought for parts of each year.

...Meteorologists measure wet bulb temperatures by wrapping a wet wick around the bulb of a thermometer. While it may seem to be an esoteric figure, it’s highly significant in heat wave situations, since the higher the wet bulb temperature gets, the more difficult it becomes for the human body to shed metabolic heat into the air through the evaporation of sweat.

In fact, mortality increases during heat waves when wet bulb temperatures reach temperatures of 88 to 91 degrees (31 to 33 Celsius)

...Washington (DC) region...The region’s all-time maximum wet-bulb temperature is 87.2 degrees (30.7 Celsius) set at Newington, Va., on July 18, 2013.

Parts of the Middle East have endured suffocating levels of heat and humidity in recent years, producing off-the-chart heat index values, which is another metric showing the combination of heat and humidity...wealthy countries...even air-condition the outdoors. Qatar, for example...

...Jonathan Buzan, a climate scientist at the University of Bern in Switzerland...has found that wet-bulb temperature extremes in the Midwest increase by about 1.8 degrees (1 Celsius) for every 1.8 degrees of global warming. This means that warming of 3.6 degrees (2 Celsius) would bring periods of wet-bulb temperatures of 95 degrees (35 Celsius) for a limited amount of time. With global warming on course to exceed 3.6 degrees, that could bring “a few days per year” with unsurvivable heat “sustained for a few days per year.” This would make agriculture that relies on outdoor picking impossible.


Colin Raymond et al. 2020. The emergence of heat and humidity too severe for human tolerance. Science Advances 08 May 2020: Vol. 6, no. 19, eaaw1838
DOI: 10.1126/sciadv.aaw1838

Humans’ ability to efficiently shed heat has enabled us to range over every continent, but a wet-bulb temperature (TW) of 35°C marks our upper physiological limit, and much lower values have serious health and productivity impacts. Climate models project the first 35°C TW occurrences by the mid-21st century. However, a comprehensive evaluation of weather station data shows that some coastal subtropical locations have already reported a TW of 35°C and that extreme humid heat overall has more than doubled in frequency since 1979. Recent exceedances of 35°C in global maximum sea surface temperature provide further support for the validity of these dangerously high TW values. We find the most extreme humid heat is highly localized in both space and time and is correspondingly substantially underestimated in reanalysis products. Our findings thus underscore the serious challenge posed by humid heat that is more intense than previously reported and increasingly severe.

maig 9, 2020, 10:02am

Scottish Startup Creates Breakthrough Brick Made From Construction Waste
Scott Snowden | May 7, 2020

A startup company called Kenoteq has launched a sustainable building brick that generates less than 10 percent of the carbon emissions released during the manufacture of regular bricks. Created by professor Gabriela Medero at Edinburgh's Heriot-Watt University, the K-Briq is 90 percent made from construction waste materials.

Originally from Brazil, Medero comes from a civil engineering background and specializes in geomaterials. “More than 10 years ago, I started looking at how we might reuse construction materials, since so much waste was being produced. Was it possible to recycle these materials and reuse them in a more circular approach? This was the driving force for me to create something better,” Medero told Forbes.

According to Medero, the K-Briq looks like an ordinary brick, weighs the same and behaves like a clay brick, but offers more effective insulation properties. However, unlike a clay brick, the K-Briq is unfired, removing the need to generate temperatures of over 1,300°C in a specialized oven. “The carbon footprint and energy demand of this alone is crazy. There is no heating involved”...

maig 11, 2020, 8:28am

COVID social distancing on my nature walk usually means stepping off the path where ever more numerous Lyme-bearing ticks lurk...
Pants tucked in pants + mask--a lovely look... NOT!

How Climate Change Is Contributing to Skyrocketing Rates of Infectious Disease
Abrahm Lustgarten | May 7, 2020

A catastrophic loss in biodiversity, reckless destruction of wildland and warming temperatures have allowed disease to explode. Ignoring the connection between climate change and pandemics would be “dangerous delusion,” one scientist said.

The scientists who study how diseases emerge in a changing environment knew this moment was coming. Climate change is making outbreaks of disease more common and more dangerous.

Today, climate warming is...driving a catastrophic loss in biodiversity that, when coupled with reckless deforestation and aggressive conversion of wildland for economic development, pushes farms and people closer to the wild and opens the gates for the spread of disease.

Aaron Bernstein, the interim director for the C-Change Center for Climate, Health and the Global Environment at Harvard University’s T.H. Chan School of Public Health, said that ignoring how climate and rapid land development were putting disease-carrying animals in a squeeze was akin to playing Russian roulette.

Scientists have not suggested that climate played any direct role in causing the current COVID-19 outbreak. Though the virus is believed to have originated with the horseshoe bat, part of a genus that’s been roaming the forests of the planet for 40 million years and thrives in the remote jungles of south China, even that remains uncertain.

Scientists have, however, been studying the coronaviruses of southern China for years and warning that swift climate and environmental change there — in both loss of biodiversity and encroachment by civilization — was going to help new viruses jump to people.

There are three ways climate influences emerging diseases. Roughly 60% of new pathogens come from animals — including those pressured by diversity loss — and roughly one-third of those can be directly attributed to changes in human land use, meaning deforestation, the introduction of farming, development or resource extraction in otherwise natural settings. Vector-borne diseases — those carried by insects like mosquitoes and ticks and transferred in the blood of infected people — are also on the rise as warming weather and erratic precipitation vastly expand the geographic regions vulnerable to contagion. Climate is even bringing old viruses back from the dead, thawing zombie contagions like the anthrax released from a frozen reindeer in 2016, which can come down from the arctic and haunt us from the past.

...What (Peter Daszak, EcoHealth Alliance’s president.) really wants — in addition to restored funding to continue his work — is the public and leaders to understand that it’s human behavior driving the rise in disease, just as it drives the climate crisis. In China’s forests, he looks past the destruction of trees and asks why they are being cut in the first place, and who is paying the cost. Metals for iPhones and palm oil for processed foods are among the products that come straight out of South Asian and African emerging disease hot spots.

“We turn a blind eye to the fact that our behavior is driving this,” he said. “We get cheap goods through Walmart, and then we pay for it forever through the rise in pandemics. It’s upside down.”

maig 13, 2020, 4:15am

Moving towards 100% renewable power in Hawaii (with a little help from sheep)
UN | 10 May 2020

The US island state of Hawaii has committed to generating 100 per cent of its power using renewable energy by 2045

...Energy costs in Hawaii, one of the world’s remotest island communities, have typically always been high, as fossil fuels have to be imported to fire the power plants.

Speaking to UN News before the oil price declined to historical lows in April 2020, David Bissell, the Chief Executive Officer of KIUC said that the cost of solar power is “significantly lower than a cost of oil-generated power” adding that “it’s getting cheaper as the technology improves.” And, importantly for businesses and domestic consumers, solar power has stabilized prices which “before could have fluctuated by 50 per cent depending on the volatility of the price of oil.”

One of the key challenges for every solar power facility is how to store electricity which is plentiful during sunny days but which, for obvious reasons, cannot be generated at night.

“Right now, during the sunniest time of the day, we are probably meeting 100 per cent of Kauai’s daytime energy needs,” said Mr. Bissell, “and now we are able to store any excess in batteries.”...

...Daryl Kaneshiro’s 350 sheep are deployed to the facility to graze on the luscious, quickly growing, tropical grass, which otherwise might envelope the solar panels and impede their productivity and power output.

“I won a competitive bid against landscaping companies which wanted to clear the grass with machines,” he said. This is just more efficient and it’s good for the environment and sustainable.”...

(Hawaii also has wind turbines.)

maig 13, 2020, 6:14am

>46 margd: The sheep should have been a no-brainer. I do wonder about the solar farms I see mounted on pavement. Waste of space!

Editat: maig 13, 2020, 10:36am

An Ancient Type of El Niño Could Awaken Because of Climate Change
Dharna Noor | May 13, 2020

A new study published in Science Advances on Wednesday* shows that as early as mid-century, global warming could cause an ancient climate pattern similar to El Niño in the Indian Ocean to reawaken. It would throw weather further into disarray, particularly in places in the global south that depend on rainfed agriculture.

...this climate pattern in the Indian Ocean may have existed during the last Ice Age, 20,000 years ago. Back then, thanks to abrupt global warming driven by natural causes, fluctuating ocean temperatures wreaked havoc on global weather patterns.

...if current global warming trends continue, we could see huge fluctuations in the Indian Ocean’s surface temperatures by 2050 similar to what happened 20,000 years ago.

“The Indian Ocean today experiences very slight year-to-year climate swings because the prevailing winds blow gently from west to east, keeping ocean conditions stable,” Pedro Di Nezio, the study’s lead author and a geophysicist at the University of Texas, told Earther in an email. “According to the simulations, global warming could reverse the direction of these winds, destabilizing the ocean and tipping the climate into swings of warming and cooling.”

Though it’s a separate phenomenon, the possible new pattern would be linked in many ways to El Niño and its opposite counterpart, La Niña. Every three to seven years, temperatures would increase or decrease by up to 2 degrees Celsius (3.6 degrees Fahrenheit), depending on whether it’s an El Niño year or a La Nina year. The changes would last between three and six months.

...Changes of a mere degree or two may not seem like a huge deal. But if this pattern re-emerges, floods, storms, and droughts will become worse and more frequent, especially in Africa, Australia, Indonesia, and India areas already severely impacted by climate change. Warm events could drive droughts over the Horn of Africa and southern India (both of which have already seen grave climate effects) and increased rainfall in Indonesia and northern Australia. Cold events could create opposite effects—for instance, the Indian peninsula could see increased rainfall.

The effects would be disastrous. A number of these locations rely on rainfed agriculture, and any shifts in precipitation could be disastrous for farmers. Drought conditions in Australia also raise the risk of dangerous bushfires, which the world got a glimpse of earlier this year. The swing between drought and flood in the Horn of Africa created the conditions for massive locust swarms, which are currently threatening food security for tens of thousands of people.

...It’s not clear exactly what threshold global warming would have to cross to trigger these shifts...make it harder to plan for the thing is clear: The biggest factor in whether or not it will emerge is our actions...


* Pedro N. DiNezio et al. 2020. Emergence of an equatorial mode of climate variability in the Indian Ocean. Science Advances 06 May 2020:
Vol. 6, no. 19, eaay7684 DOI: 10.1126/sciadv.aay7684


Presently, the Indian Ocean (IO) resides in a climate state that prevents strong year-to-year climate variations. This may change under greenhouse warming, but the mechanisms remain uncertain, thus limiting our ability to predict future changes in climate extremes. Using climate model simulations, we uncover the emergence of a mode of climate variability capable of generating unprecedented sea surface temperature and rainfall fluctuations across the IO. This mode, which is inhibited under present-day conditions, becomes active in climate states with a shallow thermocline and vigorous upwelling, consistent with the predictions of continued greenhouse warming. These predictions are supported by modeling and proxy evidence of an active mode during glacial intervals that favored such a state. Because of its impact on hydrological variability, the emergence of such a mode would become a first-order source of climate-related risks for the densely populated IO rim.

maig 13, 2020, 10:58am

The food to avoid if you care about climate change
Vox • May 13, 2020 (4:37)

Avoiding high-emission foods can have a bigger climate impact than any other consumption change.

Our consumption habits emit billions of tons of greenhouse gases into the atmosphere. Our diets account for one-fourth of those emissions.

The food we eat emits so many greenhouse emissions because of the land it takes to grow it, but it also has something to do with biology. This video explains why the production of some foods emit more than others, and which foods to avoid to be a more climate-conscious consumer.

maig 19, 2020, 8:03am

Global warming is making hurricanes stronger, study says
Doyle Rice | May 18, 2020

... the chances of hurricanes becoming a Category 3 or higher have increased each of the past four decades. Much of the death and destruction from hurricanes comes from storms of Category 3 strength or higher, which are known as "major" hurricanes.

"The change is about 8% per decade," (James Kossin of the National Oceanic and Atmospheric Administration) "In other words, during its lifetime, a hurricane is 8% more likely to be a major hurricane in this decade compared to the last decade."

The study only looked at hurricanes' wind speed, not their rainfall or storm surge....

James P. Kossin et al. 2020. Global increase in major tropical cyclone exceedance probability over the past four decades. PNAS (May 18, 2020)

Tropical cyclones (TCs), and particularly major TCs, pose substantial risk to many regions around the globe. Identifying changes in this risk and determining causal factors for the changes is a critical element for taking steps toward adaptation. Theory and numerical models consistently link increasing TC intensity to a warming world, but confidence in this link is compromised by difficulties in detecting significant intensity trends in observations. These difficulties are largely caused by known heterogeneities in the past instrumental records of TCs. Here we address and reduce these heterogeneities and identify significant global trends in TC intensity over the past four decades. The results should serve to increase confidence in projections of increased TC intensity under continued warming.

Theoretical understanding of the thermodynamic controls on tropical cyclone (TC) wind intensity, as well as numerical simulations, implies a positive trend in TC intensity in a warming world. The global instrumental record of TC intensity, however, is known to be heterogeneous in both space and time and is generally unsuitable for global trend analysis. To address this, a homogenized data record based on satellite data was previously created for the period 1982–2009. The 28-y homogenized record exhibited increasing global TC intensity trends, but they were not statistically significant at the 95% confidence level. Based on observed trends in the thermodynamic mean state of the tropical environment during this period, however, it was argued that the 28-y period was likely close to, but shorter than, the time required for a statistically significant positive global TC intensity trend to appear. Here the homogenized global TC intensity record is extended to the 39-y period 1979–2017, and statistically significant (at the 95% confidence level) increases are identified. Increases and trends are found in the exceedance probability and proportion of major (Saffir−Simpson categories 3 to 5) TC intensities, which is consistent with expectations based on theoretical understanding and trends identified in numerical simulations in warming scenarios. Major TCs pose, by far, the greatest threat to lives and property. Between the early and latter halves of the time period, the major TC exceedance probability increases by about 8% per decade, with a 95% CI of 2 to 15% per decade.

maig 23, 2020, 8:17am

What’s the more climate-conscious diet: Plant-based or place-based?
Eve Andrews | May 21, 2020

...The most effective change you can make to your diet, in terms of greenhouse gas reduction, is to go plant-based and limit meat consumption.

...There are certainly strong environmental arguments for a more locally oriented food system, including (potentially) lower fuel use from fewer transportation miles and reduced food loss from fewer steps along the distribution chain.

...the very short answer to your question, which I have answered in typically lengthy fashion, is that a diet that has tangible environmental benefits has a lot of plants and relies, at least partially, on some local producers...

Editat: maig 29, 2020, 8:27am

Planting invasive species could make our carbon problem worse
Fast-growing vegetation can reduce carbon stored underground.
Ula Chrobak | May 28, 2020 exotic plants affect the carbon balance of ecosystems. While they tend to grow rapidly, incorporating carbon from the air into their leaves, stems, and roots, they also seem to set off a chain reaction that leads to faster turnover of carbon in the soil. Soil is the largest terrestrial carbon store—more carbon is stowed away underground than above it...

...can have important implications for tree-planting projects like Trillion Trees, notes Waller in the study. When foresters plant exotic species like radiata pine and acacia, they may benefit from the fast-growing plants providing a source of wood, but they might not be as beneficial for the planet. Planting trees for the climate, the study shows, requires consideration of the entire web of interactions that determines how those new stands will affect the overall carbon balance between the terrestrial pool and the atmosphere. We may not be able to simply tree-plant our way out of the climate crisis.

...scientists estimate that kudzu (genus Pueraria) alone, one of the US’s most invasive species, causes 4.8 metric tonnes of carbon to be released per year, equivalent to that stored in nearly 4.8 hectares of forest or released by burning 2.3 billion kilograms of coal...


Invasive exotic plants have become a major problem worldwide, with transformational effects on the composition and function of ecosystems. In a multifactorial experiment in New Zealand, Waller et al. show that exotic plants accelerate carbon loss from soils through their interactions with invertebrate herbivores and soil biota (see the Perspective by Urcelay and Austin, (p 934) ). They built 160 mini-ecosystems in the field, manipulating interactions among plants, invertebrate herbivores, and soil biota. Key biological and abiotic responses were measured to quantify the relative contribution and interactions of the components of each community, revealing the potential of invasive plants to influence and suppress carbon sequestration through biotic interactions.
Science, this issue (Waller et al. 2020) p. 967; see also (Urcelay and Austin 2020) p. 934

P. Waller et al. 2020. Biotic interactions drive ecosystem responses to exotic plant invaders. Science 29 May 2020: Vol. 368, Issue 6494, pp. 967-972
DOI: 10.1126/science.aba2225

Ecosystem process rates typically increase after plant invasion, but the extent to which this is driven by (i) changes in productivity, (ii) exotic species’ traits, or (iii) novel (non-coevolved) biotic interactions has never been quantified. We created communities varying in exotic plant dominance, plant traits, soil biota, and invertebrate herbivores and measured indicators of carbon cycling. Interactions with soil biota and herbivores were the strongest drivers of exotic plant effects, particularly on measures of soil carbon turnover. Moreover, plant traits related to growth and nutrient acquisition explained differences in the ways that exotic plants interacted with novel biota compared with natives. We conclude that novel biological interactions with exotic species are a more important driver of ecosystem transformation than was previously recognized.

Carlos Urcelay and Amy T. Austin. 2020. Exotic plants get a little help from their friends. Science 29 May 2020: Vol. 368, Issue 6494, pp. 934-936
DOI: 10.1126/science.abc3587

Terrestrial ecologists have identified multifaceted controls—climate, biogeography, disturbances, and their interactions—that shape how plant communities in natural ecosystems organize in space and time. Multiple documented interactions directly link plant diversity with other biotic guilds (herbivores, root symbionts, bacteria, and pathogens) and ecosystem processes (carbon (C) and nutrient cycling) (1). However, all appears to go awry when exotic (non-native) plant species invade and establish themselves without human intervention; such changes affect the functioning and diversity of natural ecosystems (2). On page 967 in this issue, Waller et al. (3) provide insight into pathways that explain the underlying relationship between plant invasions and acceleration of a crucial ecosystem process: C turnover.

maig 29, 2020, 9:10am

Are the rates at which we observe ice shelves shrinking today representative of how fast they shrank in the past? Dowdeswell et al. (p 1020) report observations of the Antarctic seafloor that reveal the presence of submarine grounding-zone wedges on the Larsen continental shelf (see the Perspective by Jakobsson (p 939)). The authors interpret these ridges as being caused by the tidal rise and fall of the ice shelf at the grounding line, which squeezes the underlying sediments when it rests on the seafloor. From this, they calculated that ice shelf retreat at this location about 14,000 years ago was at times as much as 100 times as fast as the average over the past 10,000 years.

Science, this issue p. 1020; see also p. 939

J. A. Dowdeswell et al. 2020. Delicate seafloor landforms reveal past Antarctic grounding-line retreat of kilometers per year. Science 29 May 2020: Vol. 368, Issue 6494, pp. 1020-1024 DOI: 10.1126/science.aaz3059

A suite of grounding-line landforms on the Antarctic seafloor, imaged at submeter horizontal resolution from an autonomous underwater vehicle, enables calculation of ice sheet retreat rates from a complex of grounding-zone wedges on the Larsen continental shelf, western Weddell Sea. The landforms are delicate sets of up to 90 ridges, less than 1.5 meters high and spaced 20 to 25 meters apart. We interpret these ridges as the product of squeezing up of soft sediment during the rise and fall of the retreating ice sheet grounding line during successive tidal cycles. Grounding-line retreat rates of 40 to 50 meters per day (more than 10 kilometers per year) are inferred during regional deglaciation of the Larsen shelf. If repeated today, such rapid mass loss to the ocean would have clear implications for increasing the rate of global sea level rise.

Martin Jakobsson et al. 2020. Tracking the rapid pace of a retreating ice sheet. Science 29 May 2020: Vol. 368, Issue 6494, pp. 939-940
DOI: 10.1126/science.abc3583

Glaciers and ice sheets that extended from land into the ocean left traces behind on the seafloor called submarine glacial landforms. If mapped in sufficient detail and interpreted correctly, they can provide comprehensive information into past behaviors of glaciers and ice sheets. On page 1020 of this issue, Dowdeswell et al. (1) describe the mapping of glacial landforms in the seafloor created by a rapidly retreating ice sheet on the eastern Antarctic Peninsula. The high-resolution data suggest that the retreat rate was paced by ocean tides and at least an order of magnitude faster than modern rates observed in other sensitive areas, such as West Antarctica where the ice sheet drains into the ocean at several locations (2). The retreat on the eastern Antarctic Peninsula took place more than 10,000 years ago, pointing out the challenges in predicting the sea-level rise contribution from retreating glaciers and ice sheets in a warming climate.

juny 5, 2020, 7:43am

Atmospheric CO2 reaches peak level at NOAA observatory
Rachel Frazin | 06/04/20

The level of atmospheric carbon dioxide observed at a government facility in Hawaii reached a new peak in May...the concentration of carbon dioxide in the atmosphere recording at the at Mauna Loa observatory was as high as 417.1 parts per million (ppm).

...this was the highest monthly carbon dioxide level ever recorded. It was 2.4 ppm higher than the 2019 peak of 414.7 ppm.

...The rate of increase this year did not appear to reflect the drop in emissions caused by the coronavirus pandemic. Studies have shown that the amount of carbon emitted into the atmosphere is expected to drop this year due to a decrease in energy usage.

...Ralph Keeling, who runs the Scripps Oceanography program at Mauna Loa...“The crisis has slowed emissions, but not enough to show up perceptibly at Mauna Loa. What will matter much more is the trajectory we take coming out of this situation” ...

juny 5, 2020, 7:55am

New Study Shows Global Warming Intensifying Extreme Rainstorms Over North America
Bob Berwyn | Jun 2, 2020

The current warming trajectory could bring 100-year rainstorms as often as every 2.5 years by 2100, driving calls for improved infrastructure and planning...

Megan C. Kirchmeier-Young and Xuebin Zhang. 2020. Human influence has intensified extreme precipitation in North America.
PNAS first published June 1, 2020


Extreme precipitation is relevant to many interests, and observations show an increasing trend that is expected to continue under future projections. Although previous work has identified an anthropogenic influence on extreme precipitation at hemispheric scales, this study finds robust results for a continental scale. We establish that anthropogenic climate change has contributed to the intensification of continental and regional extreme precipitation. Furthermore, we also show that the anthropogenic influence on North American regional precipitation will lead to more frequent and intense precipitation extremes in the future.

Precipitation extremes have implications for many facets of both the human and natural systems, predominantly through flooding events. Observations have demonstrated increasing trends in extreme precipitation in North America, and models and theory consistently suggest continued increases with future warming. Here, we address the question of whether observed changes in annual maximum 1- and 5-d precipitation can be attributed to human influence on the climate. Although attribution has been demonstrated for global and hemispheric scales, there are few results for continental and subcontinental scales. We utilize three large ensembles, including simulations from both a fully coupled Earth system model and a regional climate model. We use two different attribution approaches and find many qualitatively consistent results across different methods, different models, and different regional scales. We conclude that external forcing, dominated by human influence, has contributed to the increase in frequency and intensity of regional precipitation extremes in North America. If human emissions continue to increase, North America will see further increases in these extremes.

...Discussion and Conclusions

We demonstrated an intensification of precipitation extremes over North America, with a contribution from human activity, using consistent results from different models, different methods, and physical understanding. The intensification of extreme precipitation and resulting increase in the likelihood of extreme events are expected to continue with additional warming.

Positive trends are found for the observed mean PI at the continental scale and for many regions. There is also a high likelihood of positive trends within the model ensembles. Positive trends are consistent with the expectation that extreme precipitation will increase due to increasing atmospheric humidity, which increases proportionally to the temperature increase. Larger trends in the Canadian models are likely explained by stronger warming trends. Averaged over the North American domain, annual mean temperature anomalies in CanESM2 warm 1.77 °C over 1961–2010 based on a linear trend, while CESM1 warms 1.08 °C. Our result is consistent with a study involving tropospheric temperature (26), which found larger warming in the CanESM2 than in the CESM1 large ensemble. CanESM2 overestimates surface warming compared to observations (36).

A signal of combined anthropogenic and natural external forcing can be detected in the intensification of extreme precipitation at the continental scale over North America. In some cases, this intensification can be attributed to human influence specifically. All models agree that the ALL signal is detected; the differences in scaling factors between model families (Can vs. CESM1) are consistent with the trend differences. The detection results are considered robust due to consistency across the model ensembles, and are in agreement with the likelihood of positive trends.

An increase in the probability of extreme regional PI values is also attributed to human influence. Many regions already show an increase in the probability of modeled 20-, 50-, and 100-y region-level events, with greater increases at higher levels of global warming. Even regions that do not exhibit a detectable signal in the current climate show robust increases in the likelihood of extreme precipitation events with future warming. Strong increases in the likelihood of extreme regional PI values, especially with larger GSAT increases, are consistent with increasing trends and the detection of an ALL signal.

Performing the same detailed analyses with CanESM2 and the much higher-resolution CanRCM4, and finding close agreement, allows us to verify that the global climate model can provide robust information on regional precipitation changes. However, a required condition is that the model values are standardized appropriately (e.g., through the use of the PI). As we often do not have enough information to robustly estimate past and future changes in extreme precipitation at local scales (23), robust assessment of changes at larger spatial scales can be a useful alternative to guide local climate change adaptation...

juny 8, 2020, 3:52pm

It's Official: Siberia's 10°C Hotter Than Average, We Just Had Warmest May on Record

Temperatures soared 10 degrees Celsius (°C) above average last month in Siberia, home to much of Earth's permafrost, as the world experienced its warmest May on record, the European Union's climate monitoring network said Friday.

The Copernicus Climate Change Service (C3S) said May 2020 was 0.63°C warmer than the average May from 1981 to 2010, with above average temperatures across parts of Alaska, Europe, North America, South America, swathes of Africa and Antarctica...

juny 9, 2020, 4:29pm

High Temperatures Set Off Major Greenland Ice Melt—Again
An Arctic heat wave ushered in the start of the melt season two weeks earlier than average
Chelsea Harvey | June 3, 2020

With temperatures nearly 20 degrees Fahrenheit higher than usual in some areas, the southern part of the ice sheet is melting at its highest rate this season. Forecasts suggest that the melting on Greenland’s South Dome—one of the highest elevations on the ice sheet—may be the strongest for early June since 1950.

It worries experts that Greenland could be priming for another big melt season...

juny 11, 2020, 8:01am

Assuming coral survives heat and acid until sea levels peak?

Islands Might Not Actually “Drown” As Sea Levels Rise – Here’s Why
University of Plymouth | June 10, 2020 international study led by the University of Plymouth (UK)...published in Science Advances, for the first time uses numerical modeling of island morphology alongside physical model experiments to simulate how reef islands — which provide the only habitable land in atoll nations — can respond when sea levels rise.

The results show that islands composed of gravel material can evolve in the face of overtopping waves, with sediment from the beach face being transferred to the island’s surface.

...Professor Masselink, who heads Plymouth’s Coastal Processes Research Group, said: “In the face of climate change and sea level rise, coral reef islands are among the most vulnerable coastal environments on the planet. Previous research into the future habitability of these islands typically considers them inert structures unable to adjust to rising sea level. Invariably, these studies predict significantly increased risk of coastal flooding and island inundation, and the concept of ‘island loss’ has become entrenched in discourses regarding the future of coral reef island communities. In turn, this has led to attention being focused on either building structural coastal defenses or the exodus of island communities, with limited consideration of alternative adaptation strategies.

“It is important to realize that these coral reef islands have developed over hundreds to thousands of years as a result of energetic wave conditions removing material from the reef structure and depositing the material towards the back of reef platforms, thereby creating islands. The height of their surface is actually determined by the most energetic wave conditions, therefore overtopping, flooding and island inundation are necessary, albeit inconvenient and sometime hazardous, processes required for island maintenance.”

Co-author Professor Paul Kench, currently Dean of Science at Simon Fraser University, Canada, said: “The model provides a step-change in our ability to simulate future island responses to sea level rise and better resolve what the on-ground transformations will look like for island communities. Importantly, our results suggest that island drowning within the next few decades is not universally inevitable. Understanding how islands will physically change due to sea level rise provides alternative options for island communities to deal with the consequences of climate change. It is important to stress there is no one-size-fits-all strategy that will be viable for all island communities — but neither are all islands doomed.”

...During the numerical simulations, the island crest rose by just under 0.7m, showing that islands can keep up with rising level and confirming the laboratory experiments, although the precise future rate of sea level rise will be critical in determining their future.

Reference: “Coral reef islands can accrete vertically in response to sea level rise” by Gerd Masselink, Eddie Beetham and Paul Kench, 10 June 2020, Science Advances.
DOI: 10.1126/sciadv.aay3656

juny 19, 2020, 5:16am

Climate crisis: alarm at record-breaking heatwave in Siberia
Unusually high temperatures in region linked to wildfires, oil spill and moth swarms
Damian Carrington | Wed 17 Jun 2020

...On a global scale, the Siberian heat is helping push the world towards its hottest year on record in 2020, despite a temporary dip in carbon emissions owing to the coronavirus pandemic.

Temperatures in the polar regions are rising fastest because ocean currents carry heat towards the poles and reflective ice and snow is melting away.

Russian towns in the Arctic circle have recorded extraordinary temperatures, with Nizhnyaya Pesha hitting 30C on 9 June and Khatanga, which usually has daytime temperatures of around 0C at this time of year, hitting 25C on 22 May. The previous record was 12C.

In May, surface temperatures in parts of Siberia were up to 10C above average, according to the EU’s Copernicus Climate Change Service (C3S). Martin Stendel, of the Danish Meteorological Institute, said the abnormal May temperatures seen in north-west Siberia would be likely to happen just once in 100,000 years without human-caused global heating.

In December, Russia’s president, Vladimir Putin, commented on the unusual heat: “Some of our cities were built north of the Arctic Circle, on the permafrost. If it begins to thaw, you can imagine what consequences it would have. It’s very serious.”

Thawing permafrost was at least partly to blame for a spill of diesel fuel in Siberia this month...Wildfires have raged across hundreds of thousands of hectares of Siberia’s forests...Swarms of the Siberian silk moth...larvae stripping trees of their needles and making them more susceptible to fires.

juny 19, 2020, 5:30am

Norman E. Sharpless. 2020. COVID-19 and cancer. Science 19 Jun 2020: Vol. 368, Issue 6497, pp. 1290
DOI: 10.1126/science.abd3377

Beyond clinical care, the COVID-19 pandemic has caused an unprecedented disruption throughout the cancer research community, shuttering many labs and slowing down cancer clinical trial operations. Many scientists and clinicians are pivoting their cancer research activities to study the impact of SARS-CoV-2 on cancer.With the spread of coronavirus disease 2019 (COVID-19), countries and states have instituted lockdowns. These decisions have been difficult and are sometimes described as benefiting the public health at the expense of the economy. Fear of contracting the coronavirus in health care settings has dissuaded people from screening, diagnosis, and treatment for non–COVID-19 diseases. The consequences for cancer outcomes, for example, could be substantial. What can be done to minimize this effect?

...Modeling the effect of COVID-19 on cancer screening and treatment for breast and colorectal cancer (which together account for about one-sixth of all cancer deaths) over the next decade suggests almost 10,000 excess deaths from breast and colorectal cancer deaths; that is, a ∼1% increase in deaths from these tumor types during a period when we would expect to see almost 1,000,000 deaths from these two diseases types.* The number of excess deaths per year would peak in the next year or two. This analysis is conservative, as it does not consider other cancer types, it does not account for the additional nonlethal morbidity from upstaging, and it assumes a moderate disruption in care that completely resolves after 6 months. It also does not account for regional variations in the response to the pandemic, and these effects may be less severe in parts of the country with shorter or less severe lockdowns.

Beyond clinical care, the COVID-19 pandemic has caused an unprecedented disruption throughout the cancer research community, shuttering many labs and slowing down cancer clinical trial operations. Many scientists and clinicians are pivoting their cancer research activities to study the impact of SARS-CoV-2 on cancer...

Editat: juny 20, 2020, 7:55am

Rising Seas Threaten an American Institution: The 30-Year Mortgage
Christopher Flavelle | June 19, 2020

Climate change is starting to transform the classic home loan, a fixture of the American experience and financial system that dates back generations.

...Home buyers are increasingly using (interest-only) mortgages that make it easier for them to stop making their monthly payments and walk away from the loan if the home floods or becomes unsellable or unlivable. More banks are getting buyers in coastal areas to make bigger down payments — often as much as 40 percent of the purchase price, up from the traditional 20 percent— a sign that lenders have awakened to climate dangers and want to put less of their own money at risk.

And in one of the clearest signs that banks are worried about global warming, they are increasingly getting these mortgages off their own books by selling them to government-backed buyers like Fannie Mae, where taxpayers would be on the hook financially if any of the loans fail.

...It’s not only along the nation’s rivers and coasts where climate-induced risk has started to push down home prices. In parts of the West, the growing danger of wildfires is already making it harder for homeowners to get insurance.

...In 30 years from now, if global-warming emissions follow their current trajectory, almost half a million existing homes will be on land that floods at least once a year

...banks protecting themselves in other ways, such as lending less money to home buyers in vulnerable areas, relative to the value of the homes. (equity loans)

...flood insurance isn’t likely to address the problem...because it doesn’t protect against the risk of a house losing value and ultimately becoming unsellable.

...what happens after that, when people quite simply no longer want to live in homes that keep flooding. What happens when the water starts lapping at these properties, and they get abandoned?

jul. 7, 2020, 12:14pm

The law that could make climate change illegal
Jocelyn Timperley | 7th July 2020

...The short-term cycles of government can be a real problem for climate change. Even if climate goals are laid down in law, there can often be few concrete measures to stop a succession of governments from taking decisions that collectively end up with them being missed.

...a new and ambitious climate law recently passed in Denmark tries to find a way around this problem, and some of the other common pitfalls of climate laws. It makes Denmark one of a small number of countries beginning to provide new blueprints of how government can genuinely tackle climate change. Its law could turn out to be one of the closest things yet to a law that would make climate change – or at least the lack of effort to stop it – genuinely illegal.

...Every year, the government will need to find a majority parliamentary approval of its global and national climate strategies. “The government will be held to account every year by the parliament,” says Dan Jørgensen, Denmark’s climate and energy minister. “If you’re not on track, the parliament can say, ‘Well, sorry, you’re not on track so you don’t get a majority.’ In theory, that will lead to a government having to step down.”

...evidence-based approach to what share of the global emissions cuts it is responsible for

...while the date of Denmark’s net zero target isn’t as ambitious as it could be, its promise to achieve all emissions cuts within its own borders helps to give it credibility.

...Denmark’s new law has a commitment to support other countries in cutting their emissions. It requires climate change to be integrated into foreign development aid and trade policy, and for the climate impacts of Danish imports and consumption to be considered.

...safeguard to make sure positive climate efforts in one part of its government aren’t undermined by those in another.

...courts are proving to be a powerful mechanism to force governments to take action....

jul. 7, 2020, 9:34pm

>63 Cubby.R.S.: I find it interesting that, according to Wikipedia, the guy's training consists of degrees in Peace and Global Studies and Cultural Anthropology - no science of any kind. That makes his opinions about as worthwhile as Trump's assessments of the pandemic.

jul. 7, 2020, 9:42pm

>64 alco261:

Says more about the groups he worked for than you may care to have to admit. Just thought it was interesting, it's not the first time a similar defect to the crowd has come about.

Editat: jul. 8, 2020, 10:37am

>63 Cubby.R.S.: Interesting, but one can always cherry pick a few points that don't quite support consensus.

Re Shellenberger's points, one is on shaky ground when one's lead is, "Humans are not causing a “sixth mass extinction” ...

I think scientists and environmentalists would be thrilled to have their alarm prove unfounded. However, we are edging up against climate tipping points, which are too risky to bet against, e.g.,

Editat: jul. 8, 2020, 7:36am

>56 margd: Siberian heatwave, contd.

Comparing 2020 and 2012 sea ice extents in the Laptev Sea (near Siberia; #Arctic)
Line graph time series of 2020 and 2012's daily Arctic sea ice extent in the Laptev Sea

Image ( )

- Zack Labe @ZLabe · 9:47 AM · Jul 6, 2020


It’s not just record heat that’s being pumped over the Arctic ocean from Siberia...
wildfire black carbon is along for the ride, probably darkening Arctic sea ice during 24 hours of summer sunlight

- Prof. Jason Box @climate_ice | 4:37 AM · Jul 8, 2020


Climate change may cause extreme waves in Arctic
American Geophysical Union | July 7, 2020

...The new research projects the annual maximum wave height will get up to two to three times higher than it is now along coastlines in areas of the Arctic such as along the Beaufort Sea. The new study in AGU's Journal of Geophysical Research: Oceans suggests waves could get up to 2 meters (6.6 feet) higher than current wave heights by the end of the century.

In addition, extreme wave events that used to occur once every 20 years might increase to occur once every two to five years on average, according to the study. In other words, the frequency of such extreme coastal flooding might increase by a factor of 4 to 10 by the end of this century.

"It increases the risk of flooding and erosion. It increases drastically almost everywhere," said Mercè Casas-Prat, a research scientist with Environment and Climate Change Canada's (ECCC) Climate Research Division and the lead author of the new study. "This can have a direct impact to the communities that live close to the shoreline."...


Mercé Casas‐Prat et al, Projections of extreme ocean waves in the Arctic and potential implications for coastal inundation and erosion, Journal of Geophysical Research: Oceans (2020). DOI: 10.1029/2019JC015745

Plain Language Summary
The Arctic Ocean wave climate is drastically changing with remarkable sea ice retreat. This study presents simulations of historical and future wave climates for the Arctic Ocean. The results show that the largest waves will be significantly higher and longer by the end of the century as the ice‐free season lengthens and waves become more exposed to storms in autumn. Moreover, the Arctic wave climate was projected to be more influenced by ocean waves remotely generated in the North Atlantic, which will be able to propagate to higher latitudes. This could also lead to changes in the typical wave direction patterns in the Arctic. The more energetic waves projected for the future are likely to pose a hazard to the Arctic coastlines, as the extreme wave events that can cause erosion and inundation will be more frequent and intense. This is a pressing issue as it affects many existing Arctic coastal communities and Arctic infrastructure and activities, some of which have already suffered severe damage in the past years.


jul. 11, 2020, 6:00am

Balmford A, Fisher B, Mace GM, Wilcove DS, Balmford B, COVID-19: Analogues and lessons for tackling the extinction and climate crises, Current Biology (2020) 7p preprint, doi:

...Like...twin environmental crises (the ongoing extinction and climate emergencies ), the SARS-CoV-2 pandemic perhaps at first seemed a relatively localised problem, far-removed from most people’s everyday lives. But a disease epidemic is, at heart, a phenomenon of positive feedbacks, with each new case spawning others. Human impacts on our planet are also characterised by positive feedbacks. Unravelling ecological inter-dependencies and interacting threats accelerate the extinction of species.

Anthropogenic warming triggers state shifts in ecosystems, which further increase net emissions. Moreover, lags in the dynamics of each problem – between infection and presentation of symptoms; between removal of habitat and the protracted extinction of species whose small and disconnected populations are thereby all but doomed to extinction; and between greenhouse gas emissions and the full effects of thermal expansion and ice-sheet melting on sea-level rise – mean all three systems are also characterised by considerable momentum. As a result, left unchecked for too long, our ecological and climate impacts, like those of COVID-19, have swiftly grown to become existential threats...

Their lagged impacts, non-linear escalation and complex, still poorly-understood dynamics mean that recognising and mounting effective responses to each challenge requires governments to listen to independent scientists. But, as we now know, such voices were tragically ignored during the earliest stages of this pandemic, as indeed were many years of warnings from epidemiologists and wildlife-disease experts of the immense risks of novel zoonoses emerging from wildlife markets... Scientists have likewise been warning for decades of the probability that human actions are triggering a sixth mass extinction, and of the dire consequences of major human-induced shifts in the earth’s climate. Yet with these environmental catastrophes unfolding over decades (rather than months in the case of COVID), even now government responses to them, as reflected in international commitments, are patchy and inadequate...

We suggest there are three other striking similarities in the COVID, extinction and climate crises. The first is that there is no substitute for early action...

Second, in each case mounting effective and acceptable interventions requires decision-makers and citizens to act in the interests of society as a whole, and of future generations...

Last, even examined in narrow financial terms, as the immense toll of the COVID crisis on livelihoods and the global economy becomes clearer, estimates suggest that delaying action may ironically reduce prosperity as well as cost lives...

Scientists are not inventing the threats of catastrophic climate change or of mass extinction. They are real, and they are upon us. There are many steps we can take even now to greatly diminish both crises. The consequences of continued inaction are too grave to contemplate.

jul. 12, 2020, 4:27pm

Shockingly Simple: How Farmland Could Absorb an Extra 2 Billion Tonnes of CO2 From the Atmosphere Each Year
University of Sheffield | July 11, 2020

...Major new study shows adding rock dust to farmland could remove carbon dioxide (CO2) equivalent to more than the current total emissions from global aviation and shipping combined — or around half of Europe’s current total emissions

...Research identifies the nation-by-nation potential for CO2 drawdown, as well as the costs and the engineering challenges involved

...Findings reveal the world’s highest emitters (China, India and the US) also have the greatest potential to remove CO2 from the atmosphere using this method

...Scientists suggest unused materials from mining and the construction industry could be used to help soils remove CO2 from the atmosphere

....The technique, known as enhanced rock weathering, involves spreading finely crushed basalt, a natural volcanic rock, on fields to boost the soil’s ability to extract CO2 from the air.

In the first nation-by-nation assessment, published in Nature, scientists have demonstrated the method’s potential for carbon drawdown by major economies, and identified the costs and engineering challenges of scaling up the approach to help meet ambitious global CO2 removal targets.

....The scientists suggest that meeting the demand for rock dust to undertake large-scale CO2 drawdown might be achieved by using stockpiles of silicate rock dust left over from the mining industry, and are calling for governments to develop national inventories of these materials.

Calcium-rich silicate by-products of iron and steel manufacturing, as well as waste cement from construction and demolition, could also be processed and used in this way, improving the sustainability of these industries. These materials are usually recycled as low value aggregate, stockpiled at production sites or disposed of in landfills. China and India could supply the rock dust necessary for large-scale CO2 drawdown with their croplands using entirely recycled materials in the coming decades.

The technique would be straightforward to implement for farmers, who already tend to add agricultural lime to their soils...

Reference: “Potential for large-scale CO2 removal via enhanced rock weathering with croplands” by David J. Beerling, Euripides P. Kantzas, Mark R. Lomas, Peter Wade, Rafael M. Eufrasio, Phil Renforth, Binoy Sarkar, M. Grace Andrews, Rachael H. James, Christopher R. Pearce, Jean-Francois Mercure, Hector Pollitt, Philip B. Holden, Neil R. Edwards, Madhu Khanna, Lenny Koh, Shaun Quegan, Nick F. Pidgeon, Ivan A. Janssens, James Hansen and Steven A. Banwart, 8 July 2020, Nature.
DOI: 10.1038/s41586-020-2448-9

jul. 13, 2020, 4:31am

60% of fish species could be unable to survive in current areas by 2100 – study
Valerie Yurk | 2 Jul 2020

Sixty per cent of studied fish species will be unable to survive in their current ranges by 2100 if climate warming reaches a worst-case scenario of 4-5C (7.2-9F) above pre-industrial temperatures, researchers have found.

In a study of nearly 700 fresh and saltwater fish species, researchers examined how warming water temperatures lower water oxygen levels, putting embryos and pregnant fish at risk.

...In the best-case scenario the authors considered – where the climate heats a total of 1.5C – only 10% of the surveyed species would be at risk in the next 80 years.

That scenario still puts fish which are also economically and ecologically important at risk, including Atlantic cod, swordfish, Pacific salmon, Alaska pollock and Pacific cod, which is used to produce frozen fish sticks.

Study co-author Flemming Dahlke said it was challenging to assess the impact of a 10% loss in species because a single species can be critical to the overall ecosystem...

Flemming T. Dahlke et al. 2020. Thermal bottlenecks in the life cycle define climate vulnerability of fish. Science 03 Jul 2020:
Vol. 369, Issue 6499, pp. 65-70 DOI: 10.1126/science.aaz3658

Some cope better than others

Increasingly, research is revealing how organisms may, or may not, adapt to a changing climate. Understanding the limitations placed by a species's physiology can help to determine whether it has an immediate potential to deal with rapid change. Many studies have looked at physiological tolerance to climate change in fishes, with results indicating a range of responses. Dahlke et al. conducted a meta-analysis to explore how life stage may influence a species's ability to tolerate temperature change (see the Perspective by Sunday). They found that embryos and breeding adult fishes are much more susceptible to temperature change than those in other life stages and that this factor must therefore be considered in evaluations of susceptibility.

Science, this issue p. 65; see also p. 35

Species’ vulnerability to climate change depends on the most temperature-sensitive life stages, but for major animal groups such as fish, life cycle bottlenecks are often not clearly defined. We used observational, experimental, and phylogenetic data to assess stage-specific thermal tolerance metrics for 694 marine and freshwater fish species from all climate zones. Our analysis shows that spawning adults and embryos consistently have narrower tolerance ranges than larvae and nonreproductive adults and are most vulnerable to climate warming. The sequence of stage-specific thermal tolerance corresponds with the oxygen-limitation hypothesis, suggesting a mechanistic link between ontogenetic changes in cardiorespiratory (aerobic) capacity and tolerance to temperature extremes. A logarithmic inverse correlation between the temperature dependence of physiological rates (development and oxygen consumption) and thermal tolerance range is proposed to reflect a fundamental, energetic trade-off in thermal adaptation. Scenario-based climate projections considering the most critical life stages (spawners and embryos) clearly identify the temperature requirements for reproduction as a critical bottleneck in the life cycle of fish. By 2100, depending on the Shared Socioeconomic Pathway (SSP) scenario followed, the percentages of species potentially affected by water temperatures exceeding their tolerance limit for reproduction range from ~10% (SSP 1–1.9) to ~60% (SSP 5–8.5). Efforts to meet ambitious climate targets (SSP 1–1.9) could therefore benefit many fish species and people who depend on healthy fish stocks.

jul. 15, 2020, 3:59am

Biden unveils a more aggressive and progressive climate plan
Mike Memoli and Marianna Sotomayor | July 14, 2020

WILMINGTON, Del. — Linking the urgent need to address a changing climate with the nation’s growing economic crisis, Joe Biden on Tuesday outlined a $2 trillion plan to rebuild American cities and towns through investments in clean energy technologies that would finally deliver on what he said was President Donald Trump’s failed promise to deliver an infrastructure plan.

...The plan notably keeps Biden’s 2050 timeline to establish a 100 percent clean energy economy with net-zero emissions, but puts in place a more achievable goal to cut the nation’s carbon footprint in half by 2035.


jul. 17, 2020, 9:05am

Planting native species of trees, shrubs, flowers and grasses can cool the summer day-time temperature of an area by over 4 C in a decade.
U Waterloo Media Relations | July 16, 2020

Planting native species of trees, shrubs, flowers and grasses can cool the summer day-time temperature of an area by over 4 C in a decade.

University of Waterloo researchers used a new thermal camera on the International Space Station (ISS) called ECOSTRESS to gather images that show temperature decreases over time when biodiverse, native species are restored to areas of Southern Ontario.

“I’ve advised local governments that restoring natural areas with diverse native plants and trees is a very effective way for us to adapt to a hotter summer climate on a local level," said (author Jonas) Hamberg. "Native species are adapted to the local environment and can cool their surroundings better. For example, native tall-grass species have deeper roots and can pull up water to cool, much like a water-cooled AC, long after non-native lawn grasses have gone yellow and dry."...

* L. Jonas Hamberg et al. 2020. Surface Temperature as an Indicator of Plant Species Diversity and Restoration in Oak Woodland.Volume 113. June 2020. Article 106249.


Thermal imagery was acquired from Landsat satellites 5, 7 and 8 for each growing season in 2002–2018 (excluding 2012) and from the ECOSTRESS thermal instrument on the International Space Station (ISS) for 2018. Three of the 31 fields were surveyed annually 2007–2018 for plant species diversity, ground and canopy cover, and number of woody stems. All surface temperatures were measured in percentage difference relative to adjacent mature forest areas that exhibited stable temperature responses over time.

We found (1) a mean decrease in temperature of 1.5 percentage point per year since restoration; (2) a decrease of 4 percentage points of diurnal temperature difference per year since restoration for the same fields; and (3) when controlling for ground and canopy cover, stem count, and Normalized Difference Vegetation Index, an increase of one ‘effective number’ of plant species diversity decreased relative temperature by 5 percentage points. These results correspond to a decrease of daytime temperature of 4.5 °C over 12 years, a decrease of diurnal temperature variation of 5 °C in 8 years and a 0.3 °C decrease per extra plant species.

Our results offer compelling evidence that relative temperature has potential to be used as an indicator to measure ecosystem change resulting from restoration.

jul. 24, 2020, 7:00am

Reminder: as bad as analysis below is, it does not address other outcomes such as absorption of CO2 by seas.
(Remember the clear, dead lakes killed by acid rain? )

After 40 years, researchers finally see Earth’s climate destiny more clearly
Paul Voosen | Jul. 22, 2020 , 10:00 AM

It seems like such a simple question: How hot is Earth going to get? Yet for 40 years, climate scientists have repeated the same unsatisfying answer: If humans double atmospheric carbon dioxide (CO2) from preindustrial levels, the planet will eventually warm between 1.5°C and 4.5°C—a temperature range that encompasses everything from a merely troubling rise to a catastrophic one. (Humanity has already emitted enough CO2 to be halfway to the doubling point of 560 parts per million, and many emissions scenarios have the planet reaching that threshold by 2060.)

Now, in a landmark effort,* a team of 25 scientists has significantly narrowed the bounds on this critical factor, known as climate sensitivity. The assessment, conducted under the World Climate Research Programme (WCRP) and publishing this week in Reviews of Geophysics, relies on three strands of evidence: trends indicated by contemporary warming, the latest understanding of the feedback effects that can slow or accelerate climate change, and lessons from ancient climates. They support a likely warming range of between 2.6°C and 3.9°C, says Steven Sherwood, one of the study’s lead authors and a climate scientist at the University of New South Wales. “This is the number that really controls how bad global warming is going to be.”

...The first line of evidence they considered was modern-day warming.

...Second, the team probed individual climate feedbacks.

...The final range represents a 66% confidence interval, matching IPCC’s traditional “likely” range. The WCRP team also calculated a 90% confidence interval, which ranges from 2.3°C to 4.7°C, leaving a slight chance of a warming above 5°C.

...Finally, the team looked at records from two past climates—20,000 years ago, at the peak of the last ice age, and a warm period 3 million years ago, the last time atmospheric CO2 levels were similar to today’s.

Either way, the report has a simple takeaway, (co-author) Sherwood says: A doubling of CO2 all but guarantees warming of more than 2°C. “Three major lines of evidence are all very difficult to reconcile with the lower end of climate sensitivity.”...


* An assessment of Earth’s climate 1sensitivity using multiple lines of evidence ( 166 p )

Authors: S. Sherwood, M.J. Webb, J.D. Annan, K.C. Armour, P.M. Forster, J.C. Hargreaves, G.Hegerl, S. A. Klein, K.D. Marvel, E.J. Rohling, M. Watanabe, T. Andrews, P. Braconnot, C.S. Bretherton, G.L. Foster, Z. Hausfather, A.S. von der Heydt, R. Knutti, T. Mauritsen, J.R. Norris, C. Proistosescu, M. Rugenstein, G.A. Schmidt, K.B. Tokarska, M.D. Zelinka

Key Points:
●We assess evidence relevant to Earth’s climate sensitivity S: feedback process understanding, and the historical and paleo-climate records.
●All three lines of evidence are difficult to reconcile with S 4.5 K.47
●A Bayesian calculation finds a 66% range of 2.6-3.9 K, which remains within the bounds 2.3-4.5 K under plausible robustness tests.

jul. 25, 2020, 5:51am

Where Will Everyone Go?
Abrahm Lustgarten, Photography by Meridith Kohut | July 23, 2020

ProPublica and The New York Times Magazine, with support from the Pulitzer Center, have for the first time modeled how climate refugees might move across international borders. This is what we found.

...For most of human history, people have lived within a surprisingly narrow range of temperatures, in the places where the climate supported abundant food production. But as the planet warms, that band is suddenly shifting north. According to a pathbreaking recent study in the journal Proceedings of the National Academy of Sciences, the planet could see a greater temperature increase in the next 50 years than it did in the last 6,000 years combined. By 2070, the kind of extremely hot zones, like in the Sahara, that now cover less than 1% of the earth’s land surface could cover nearly a fifth of the land, potentially placing 1 of every 3 people alive outside the climate niche where humans have thrived for thousands of years. Many will dig in, suffering through heat, hunger and political chaos, but others will be forced to move on. A 2017 study in Science Advances found that by 2100, temperatures could rise to the point that just going outside for a few hours in some places, including parts of India and Eastern China, “will result in death even for the fittest of humans.”

...The stark policy choices are already becoming apparent. As refugees stream out of the Middle East and North Africa into Europe and from Central America into the United States, an anti-immigrant backlash has propelled nationalist governments into power around the world. The alternative, driven by a better understanding of how and when people will move, is governments that are actively preparing, both materially and politically, for the greater changes to come.

...I. A Different Kind of Climate Model
...quantify how and where climate change would cause people to move.

...II. How Climate Moves People
...Most would-be migrants don’t want to move away from home. Instead, they’ll make incremental adjustments to minimize change, first moving to a larger town or a city. It’s only when those places fail them that they tend to cross borders, taking on ever riskier journeys, in what researchers call “stepwise migration.”

...III. The Choice
...There is no more natural and fundamental adaptation to a changing climate than to migrate. It is the obvious progression the earliest Homo sapiens pursued out of Africa, and the same one the Mayans tried 1,200 years ago.

...Our modeling and the consensus of academics point to the same bottom line: If societies respond aggressively to climate change and migration and increase their resilience to it, food production will be shored up, poverty reduced and international migration slowed — factors that could help the world remain more stable and more peaceful. If leaders take fewer actions against climate change, or more punitive ones against migrants, food insecurity will deepen, as will poverty. Populations will surge, and cross-border movement will be restricted, leading to greater suffering. Whatever actions governments take next — and when they do it — makes a difference.

The window for action is closing. The world can now expect that with every degree of temperature increase, roughly a billion people will be pushed outside the zone in which humans have lived for thousands of years. For a long time, the climate alarm has been sounded in terms of its economic toll, but now it can increasingly be counted in people harmed. The worst danger, Hinde warned on our walk, is believing that something so frail and ephemeral as a wall can ever be an effective shield against the tide of history. “If we don’t develop a different attitude,” he said, “we’re going to be like people in the lifeboat, beating on those that are trying to climb in.”

jul. 26, 2020, 10:02am

6 Ways to Cool Off Without Air Conditioning
These methods of cooling your home and its occupants are cheaper and kinder to the planet than running the A/C
Mariana Pickering | 7/26/2020

(see comments for some interesting ideas)

jul. 29, 2020, 9:33am

After carbon dioxide (CO2), methane (CH4) was responsible for ~23% of climate change in the 20th century.
Concentrations have (increased) by (more than) 150% since industrial activities & intensive agriculture began.

Learn more about its complex patterns & various sources:

Methane Sources (1:59)
This visualization shows the complex patterns of methane emissions produced globally
between December 2017 and December 2018 from different sources.

-NASA Climate @NASAClimate | 7:14 PM · Jul 23, 2020

jul. 29, 2020, 9:36am

Blog | There Is No Impending 'Mini Ice Age'
- NASA Global Climate Change | February 13, 2020

jul. 30, 2020, 6:22am

Siberia’s ‘gateway to the underworld’ grows as record heat wave thaws permafrost
Richard Stone | Jul. 28, 2020

...Based on observations at 100 field sites, northern permafrost released on average about 600 million tons more carbon than vegetation absorbed each year from 2003 to 2017, scientists estimated in October 2019.

...As the elements carve up more of the Batagay megaslump (in eastern Siberia), it could transport scientists deeper into time. Glaciers scour away soil as they advance, but they largely bypassed Siberia during recent ice ages, leaving the permafrost in some areas hundreds of meters thick. For decades, as the hot summers liquefied its ice-rich soil, Batagay’s headwall advanced about 10 meters per year, says Frank Guenther, a permafrost researcher at the University of Potsdam. Since 2016, he says, that rate has surged to 12 to 14 meters per year. It’s harder to peg how fast the slump is deepening, and thus how much farther back in time the thaw is penetrating. The most ancient permafrost ever dated, from Canada’s Yukon territory, is 740,000 years old. As much as climate watchers may cringe at the thought, several more roasting Siberian summers could push the Batagay megaslump to claim another record.

ag. 8, 2020, 9:14am

How Venus and Mars Can Teach Us About the Past and Future of Earth
European Space Agency (ESA) | August 7, 2020

...Despite starting with the same ingredients, Earth’s neighbors suffered devastating climate catastrophes and could not hold on to their water for long. Venus became too hot and Mars too cold; only Earth became the ‘Goldilocks’ planet with the just-right conditions. Did we come close to becoming Mars-like in a previous ice age? How close are we to the runaway greenhouse effect that plagues Venus? Understanding the evolution of these planets and the role of their atmospheres is tremendously important for understanding climatic changes on our own planet as ultimately the same laws of physics govern all. The data returned from our orbiting spacecraft provide natural reminders that climate stability is not something to be taken for granted...

Editat: ag. 11, 2020, 8:17am

EPA Reportedly Set To Rescind Obama-Era Methane Rules As White House Speeds Environmental Rollbacks Ahead Of Election
Alison Durkee | Aug 10, 2020

The Wall Street Journal reports the Environmental Protection Agency is preparing to finalize new rules this week rescinding Obama-era regulations of methane gas emissions for oil-and-gas producers, as the Trump administration continues its systematic rollback of environmental regulations—which is reportedly speeding up ahead of November before a Democratic administration potentially takes over.

The proposed rule changes...will apply to wells drilled since 2016 and “remove the largest pipelines, storage sites and other parts of the transmission system from EPA oversight of smog and greenhouse-gas emissions,” the Journal reports, rescinding requirements for energy producers to have systems to detect methane leaks and reducing the frequency for checks for leaks of other pollutants.

..The EPA will reportedly argue in the new rules that the Obama administration did not go through the proper process when it initially established the regulation, which the Journal notes would make it more difficult for a subsequent Democratic administration to reverse the rollback without a congressional mandate.

...While small and midsize oil and gas producers favor rescinding the rules, the rule change is opposed by large energy giants like Exxon Mobil, BP and Royal Dutch Shell, who say it will undermine their claims that their natural gas is a “cleaner” fossil fuel.

The New York Times reported in March that the Trump administration is on an “aggressive timeline” to roll back environmental regulations ahead of the November election, and further rollbacks to inspection requirements were reportedly dropped because they could potentially stretch out the process beyond the end of Trump’s term...

ag. 13, 2020, 8:10am

Concrete, a Centuries Old Material, Gets a New Recipe
Jane Margolies | Aug. 11, 2020

...concrete is...responsible for about 8 percent of global carbon emissions. If concrete were a country, it would rank third in emissions behind China and the United States.

...Fiddling with concrete’s recipe is not new, however. The Romans used a formula involving lime and volcanic rock. In the early 19th century, an English bricklayer invented Portland cement, still the most widely used type, whose production involves combining limestone and clay and heating it to blistering temperatures. Each construction project today has its own concrete mix, designed by structural engineers to take into account how and where it will be used.

...Before climate change became a pressing issue, concrete producers sought to reduce the amount of cement in their mixes for the simple reason that it tended to be expensive, in part because of the energy-intensive heating in producing it.

Decades ago, they began substituting some of the cement with cheaper fly ash, a byproduct of coal-burning plants, and slag, a byproduct of steel production. Using such materials had the added benefit of diverting them from landfills, and they were also found to improve concrete’s performance. Only in recent years has concrete with fly ash and slag been promoted as a greener product.

But now there’s a hitch: With coal plants being retired, fly ash is not as plentiful as it once was.

...Recycled post-consumer glass — which otherwise might be sent to landfills — is being crushed into a powder, known as ground-glass pozzolan, that can be used in place of some of the cement in concrete.

The cement industry is promoting Portland-limestone cement, which reduces carbon 10 percent, according to the Portland Cement Association, a trade group.

Several new ways to make concrete greener employ waste carbon dioxide...

...Green concrete can be more expensive, said Jay Moreau, chief executive of the U.S. aggregates and construction material division of LafargeHolcim, a Swiss company. Last month, LafargeHolcim made a concrete mix that lowers carbon 30 percent a standard part of its offerings. But as the company creates mixes that reduce carbon by 50 percent, the concrete could cost 5 percent more, Mr. Moreau said.

Central said it had kept the price of its low-emissions concrete on a par with conventional concrete, hoping to attract customers that want to reduce the carbon footprint of their buildings...“We see it as a market differentiator and a way to win more projects”...

ag. 13, 2020, 8:22am

Why meteorologists hold their breath when a volcano erupts in the tropics
Adriana Navarro | Aug. 12, 2020

Volcano eruptions have had a history of not just blotting out the sky, but even impacting global temperatures.

...This happens, AccuWeather Senior Meteorologist and Long-Range Forecaster Paul Pastelok explains, through a large enough eruption pushing sulfur dioxide and ash to the upper troposphere and into the stratosphere, which is at an elevation of about 30,000 feet, or a bit over 5 miles.

..."Volcanoes do affect the weather, and some major ones affect the climate if you define climate as anything beyond a year or two," Dr. Joel Myers, Founder CEO and Chairman of AccuWeather, said.

A clear example of this occurred a little over 200 years ago when the Tambora volcano, also located in what is now Indonesia, erupted in April 1815, killing more than 600,000 people.

The eruption "caused a few years of cold weather, some of it extraordinary," Myers explained. "This includes 1816, the 'Year Without a Summer,' when frost occurred in New England in every month of the year -- affecting crops and on one July day when snow flurries were reported in Long Island Sound."

The location of the volcanic eruption will also determine how likely it is to impact global temperatures.

"When volcanoes erupt in the tropical regions, they have a better chance to impact global temperatures than northern eruptions," (AccuWeather Senior Meteorologist and Long-Range Forecaster Paul Pastelok ) said.

This is because most of the sulfur dioxide and ash spewed from eruptions north are more likely to get caught up in the northern polar jet stream, possibly being dispersed out quickly over the northern latitudes. Likewise, the southern polar jet stream acts the same below the tropics.

"They both do the same thing, pushing ash and sulfur, leading to blocking particle formation in the upper atmosphere, which prohibits too much radiant energy to reach the lower atmosphere, thus less warming overall."

An eruption in the tropics however, can loom "over a greater area and take a longer duration for the aerosols to disperse over time with a slower jet stream pattern over the tropics," Pastelok said.

Once the aerosols infiltrate the stratosphere and begin to linger, they begin to block energy from the sun, gradually warming the stratosphere. As this happens, Pastelok explained, the area over and near the tropics cools more.

"In the winter, this weakens the temperature difference between the tropical region and the far northern latitudes," Pastelok said. "This can impact certain tele-connections like the Arctic Oscillation (AO), which, when strong, keeps colder air bottled up near the poles, but when weakened can allow colder air to spill toward the middle latitudes."

The pocket of cold air that sits over the poles, occasionally escaping through the AO is referred to as the polar vortex.

The AO fluctuates throughout the winter, but a stronger temperature difference would lead to a frequently weaker AO, meaning colder air reaching the U.S. more frequently.

A weaker temperature difference, which sulfur dioxide and ash expelled into the stratosphere in the tropics can lead to, would more frequently lead to a stronger AO, Pastelok explained. A stronger AO means certain areas like the eastern U.S. remain warmer than normal during the wintertime.

"Global temperatures can be impacted by 1 to 2 degrees C over a two-to-three-year period during a major eruption," Pastelok said.

The last significant volcanic eruption to throw global temperatures was the eruption of Mount Pinatubo in the Philippines in 1991. The eruption spewed ash and debris up to 131,234 feet, over 24 miles, into the air and unleashed about 17 megatons of sulfur dioxide into the atmosphere.

As a result, Dr. Howard Diamond, manager of the Climate Science Program at NOAA's Air Resources Laboratory told AccuWeather, there was an observed surface cooling in the Northern Hemisphere of up to 0.5 to 0.6 degrees Celsius, and a cooling of perhaps as large as minus 0.4 degrees Celsius across parts of the world from 1992 to 1993. (margd: resulting in measurable difference in fish production in Lake Ontario)

ag. 15, 2020, 8:26am

'Canary in the coal mine': Greenland ice has shrunk beyond return, study finds
Cassandra Garrison | August 14, 2020

...Scientists studied data on 234 glaciers across the Arctic territory spanning 34 years through 2018 and found that annual snowfall was no longer enough to replenish glaciers of the snow and ice being lost to summertime melting.

That melting is already causing global seas to rise about a millimeter on average per year. If all of Greenland’s ice goes, the water released would push sea levels up by an average of 6 meters — enough to swamp many coastal cities around the world. This process, however, would take decades.

...The Arctic has been warming at least twice as fast as the rest of the world for the last 30 years, an observation referred to as Arctic amplification. The polar sea ice hit its lowest extent for July in 40 years.

The new study suggests the territory’s ice sheet will now gain mass only once every 100 years — a grim indicator of how difficult it is to re-grow glaciers once they hemorrhage ice.

In studying satellite images of the glaciers, the researchers noted that the glaciers had a 50% chance of regaining mass before 2000, with the odds declining since.

...The sobering findings should spur governments to prepare for sea-level rise, (lead author Michalea King, a glaciologist at Ohio State University) said.

...Still, the world can still bring down emissions to slow climate change, scientists said. Even if Greenland can’t regain the icy bulk that covered its 2 million square kilometers, containing the global temperature rise can slow the rate of ice loss.

“When we think about climate action, we’re not talking about building back the Greenland ice sheet,” said Twila Moon, a glaciologist at the National Snow and Ice Data Center who was not involved in the study. “We’re talking about how quickly rapid sea-level rise comes to our communities, our infrastructure, our homes, our military bases.”


Michalea D. King et al. 2020. Dynamic ice loss from the Greenland Ice Sheet driven by sustained glacier retreat. Communications Earth & Environment volume 1, Article number: 1 (13 Aug 2020)

The Greenland Ice Sheet is losing mass at accelerated rates in the 21st century, making it the largest single contributor to rising sea levels. Faster flow of outlet glaciers has substantially contributed to this loss, with the cause of speedup, and potential for future change, uncertain. Here we combine more than three decades of remotely sensed observational products of outlet glacier velocity, elevation, and front position changes over the full ice sheet. We compare decadal variability in discharge and calving front position and find that increased glacier discharge was due almost entirely to the retreat of glacier fronts, rather than inland ice sheet processes, with a remarkably consistent speedup of 4–5% per km of retreat across the ice sheet. We show that widespread retreat between 2000 and 2005 resulted in a step-increase in discharge and a switch to a new dynamic state of sustained mass loss that would persist even under a decline in surface melt.


Editat: ag. 24, 2020, 8:11am

Efforts to restore flow, to not use Great Lakes water, and to prevent flooding--removing dams, reducing consumptive uses (GLs Compact), opening gates of Moses Saunders Hydroelectric dam--helps aquatic species and humans in Great Lakes basin, but in time of climate change (melting ice, thermal expansion of sea water) contributes to sea level rise and perhaps to desalination/slowing of Europe-warming Atlantic Meridional Overturning Circulation?

NASA Research Reveals the True Causes of Sea Level Rise Since 1900
Jet Propulsion Laboratory | August 23, 2020
Greenland Ice Sheet Meltwater Rivers

...By gaining new insights to historic measurements, scientists can better forecast how each of these factors will affect sea level rise and how this rise will impact us in the future.

For example, in its recent flooding report, the National Oceanic and Atmospheric Administration (NOAA) noted a rapid increase in sea level rise-related flooding events along U.S. coasts over the last 20 years, and they are expected to grow in extent, frequency, and depth as sea levels continue to rise. (infographic)

...known contributors to sea level rise from 1900 to 2018

The researchers found that estimates of global sea level variations based on tide-gauge observations had slightly overestimated global sea levels before the 1970s. (Located at coastal stations scattered around the globe, tide gauges are used to measure sea level height.) They also found that mountain glacier meltwater was adding more water to the oceans than previously realized but that the relative contribution of glaciers to sea level rise is slowly decreasing. And they discovered that glacier and Greenland ice sheet mass loss explain the increased rate of sea level rise before 1940.

In addition, the new study found that during the 1970s, when dam construction was at its peak, sea level rise slowed to a crawl. Dams create reservoirs that can impound freshwater that would normally flow straight into the sea.

“That was one of the biggest surprises for me,” said lead researcher Thomas Frederikse, a postdoctoral fellow at JPL, referring to the peak in global dam projects at that time. “We impounded so much freshwater, humanity nearly brought sea level rise to a halt.”

Since the 1990s, however, Greenland and Antarctic ice sheet mass loss and thermal expansion have accelerated sea level rise, while freshwater impoundment has decreased. As our climate continues to warm, the majority of this thermal energy is absorbed by the oceans, causing the volume of the water to expand. In fact, ice sheet melt and thermal expansion now account for about two-thirds of observed global mean sea level rise. Mountain glacier meltwater currently contributes another 20%, while declining freshwater water storage on land adds the remaining 10%.

All told, sea levels have risen on average 1.6 millimeters (0.063 inches) per year between 1900 and 2018. In fact, sea levels are rising at a faster rate than at any time in the 20th century...


“The causes of sea-level rise since 1900” by Thomas Frederikse, Felix Landerer, Lambert Caron, Surendra Adhikari, David Parkes, Vincent W. Humphrey, Sönke Dangendorf, Peter Hogarth, Laure Zanna, Lijing Cheng and Yun-Hao Wu, 19 August 2020, Nature.
DOI: 10.1038/s41586-020-2591-3

The rate of global-mean sea-level rise since 1900 has varied over time, but the contributing factors are still poorly understood1. Previous assessments found that the summed contributions of ice-mass loss, terrestrial water storage and thermal expansion of the ocean could not be reconciled with observed changes in global-mean sea level, implying that changes in sea level or some contributions to those changes were poorly constrained2,3. Recent improvements to observational data, our understanding of the main contributing processes to sea-level change and methods for estimating the individual contributions, mean another attempt at reconciliation is warranted. Here we present a probabilistic framework to reconstruct sea level since 1900 using independent observations and their inherent uncertainties. The sum of the contributions to sea-level change from thermal expansion of the ocean, ice-mass loss and changes in terrestrial water storage is consistent with the trends and multidecadal variability in observed sea level on both global and basin scales, which we reconstruct from tide-gauge records. Ice-mass loss—predominantly from glaciers—has caused twice as much sea-level rise since 1900 as has thermal expansion. Mass loss from glaciers and the Greenland Ice Sheet explains the high rates of global sea-level rise during the 1940s, while a sharp increase in water impoundment by artificial reservoirs is the main cause of the lower-than-average rates during the 1970s. The acceleration in sea-level rise since the 1970s is caused by the combination of thermal expansion of the ocean and increased ice-mass loss from Greenland. Our results reconcile the magnitude of observed global-mean sea-level rise since 1900 with estimates based on the underlying processes, implying that no additional processes are required to explain the observed changes in sea level since 1900.

ag. 24, 2020, 9:00am

James Veitch @veitchtweets | 8:50 AM · Aug 19, 2020:

Two thousand years of global temperatures in twenty seconds
0:27 ( )

ag. 31, 2020, 5:20am

Paul Voosen. 2020. Growing underwater heat blob speeds demise of Arctic sea ice. Science (Aug. 25, 2020). doi:10.1126/science.abe4945

...Arctic sea ice is itself an endangered species. Next month its extent will reach its annual minimum, which is poised to be among the lowest on record. The trend is clear: Summer ice covers half the area it did in the 1980s, and because it is thinner, its volume is down 75%. With the Arctic warming three times faster than the global average, most scientists grimly acknowledge the inevitability of ice-free summers, perhaps as soon as 2035. “It’s definitely a when, not an if,” says Alek Petty, a polar scientist at NASA’s Goddard Space Flight Center.

Now, he and others are learning that a warming atmosphere is far from the only factor speeding up the ice loss. Strengthening currents and waves are pulverizing the ice. And a study published last week suggests deep heat in the Arctic Ocean has risen and is now melting the ice from below.

Ice has kept its grip on the Arctic with the help of an unusual temperature inversion in the underlying waters. Unlike the Atlantic or Pacific oceans, the Arctic gets warmer as it gets deeper. Bitter winters and chilly, buoyant freshwater from Eurasian rivers cool its surface layers, which helps preserve the underside of the ice. But at greater depths sits a warm blob of salty Atlantic water, thought to be safely separated from the sea ice.

As the reflective ice melts, however, it is replaced by darker water, which absorbs more of the Sun’s energy and warms. Those warming surface waters are likely migrating down into the blob, which robotic temperature probes, moorings, and oceanographic surveys show is steadily warming and growing. With enough heat to melt the Arctic’s ice three to four times over, the blob could devour the ice from below if the barrier of the cold surface layers ever dissipates.

Measurements from the eastern Arctic Ocean, published last week in the Journal of Climate, show the blob, usually found 150 meters below or deeper, has recently moved up to within 80 meters of the surface. Increased turbulence means some of that heat is now melting ice, says Igor Polyakov, an oceanographer at the University of Alaska, Fairbanks. “This heat has become, regionally, the key forcing for sea ice decay.”

The process, called “Atlantification,” is already well underway in the Barents Sea, north of Norway, where fingers of warm Atlantic water have spread north and risen, melting sea ice even in winter months. The invasion shows no sign of stopping, says Helene Asbjørnsen, an oceanographer at the University of Bergen who has helped chart this migration. “Ultimately we expect it to extend into the Arctic more.”

set. 1, 2020, 8:39am

Tracking 3 Decades of Dramatic Glacial Lake Growth (1:54)
NASA Goddard • Aug 31, 2020

In the largest-ever study of glacial lakes, researchers using a 30-year satellite data record have found that the volume of these lakes worldwide has increased by about 50% since 1990 as glaciers melt and retreat due to climate change.


RELEASE 20-080
Global Survey Using NASA Data Shows Dramatic Growth of Glacial Lakes
NASA | Aug. 31, 2020

...lead author Dan Shugar of the University of Calgary in Canada...points out that while water from melting glaciers stored in glacial lakes is a relatively small contributor to overall sea level rise, it can have a major impact on mountain communities downstream of these glacial lakes.

Glacial lakes are not stable like the lakes in which most people are used to swimming or boating because they are often dammed by ice or glacial sediment called a moraine, which is composed of loose rock and debris that is pushed to the front and sides of glaciers. Rather, they can be quite unstable and can burst their banks or dams, causing massive floods downstream. These kinds of floods from glacial lakes, known as glacial lake outburst floods, have been responsible for thousands of deaths over the past century, as well as the destruction of villages, infrastructure, and livestock. A glacial lake outburst flood affected the Hunza Valley in Pakistan in May 2020.

“This is an issue for many parts of the world where people live downstream from these hazardous lakes, mostly in the Andes and in places like Bhutan and Nepal, where these floods can be devastating,” Shugar said. “Fortunately, organizations like the United Nations are facilitating a lot of monitoring and some mitigation work where they’re lowering the lakes to try and decrease the risks.”

In North America, the risks posed by a glacial lake outburst flood are lower.

“We don’t have much in the way of infrastructure or communities that are downstream,” Shugar said. “But we’re not immune to it.”

set. 2, 2020, 6:19am

Ice Sheet Melting Is Perfectly in Line With Our Worst-Case Scenario, Scientists Warn

The Greenland and Antarctic ice sheets, which hold enough frozen water to lift oceans 65 metres, are tracking the UN's worst-case scenarios for sea level rise, researchers said Monday, highlighting flaws in current climate change models.

Mass loss from 2007 to 2017 due to melt-water and crumbling ice aligned almost perfectly with the Intergovernmental Panel for Climate Change's (IPCC) most extreme forecasts, which see the two ice sheets adding up to 40 centimetres (nearly 16 inches) to global oceans by 2100, they reported in Nature Climate Change.

Such an increase would have a devastating impact worldwide, increasing the destructive power of storm surges and exposing coastal regions home to hundreds of millions of people to repeated and severe flooding.

That is nearly three times more than mid-range projections from the IPCC's last major Assessment Report in 2014, which predicts a 70-centimetre rise in sea level from all sources, including mountain glaciers and the expansion of ocean water as it warms...


Thomas Slater et al. 2020. Ice-sheet losses track high-end sea-level rise projections (comment). Nature Climate Change (31 Aug 2020)

Observed ice-sheet losses track the upper range of the IPCC Fifth Assessment Report sea-level predictions, recently driven by ice dynamics in Antarctica and surface melting in Greenland. Ice-sheet models must account for short-term variability in the atmosphere, oceans and climate to accurately predict sea-level rise.

Editat: set. 4, 2020, 8:46am

New mathematical method shows how climate change led to fall of ancient civilization
Rochester Institute of Technology | September 3, 2020

...In an article recently featured in the journal Chaos: An Interdisciplinary Journal of Nonlinear Science, Nishant Malik, assistant professor in RIT's School of Mathematical Sciences, outlined the new technique he developed and showed how shifting monsoon patterns led to the demise of the Indus Valley Civilization, a Bronze Age civilization contemporary to Mesopotamia and ancient Egypt.*

...His analysis showed there was a major shift in monsoon patterns just before the dawn of this civilization and that the pattern reversed course right before it declined, indicating it was in fact climate change that caused the fall...

* ~3000 BCE, SW South Aisa, now Pakistan and India


Nishant Malik. 2020. Uncovering transitions in paleoclimate time series and the climate driven demise of an ancient civilization, Chaos: An Interdisciplinary Journal of Nonlinear Science (Aug 3, 2020). DOI: 10.1063/5.0012059

We present a hybrid framework appropriate for identifying distinct dynamical regimes and transitions in a paleoclimate time series. Our framework combines three powerful techniques used independently of each other in time series analysis: a recurrence plot, manifold learning through Laplacian eigenmaps, and Fisher information metric. The resulting hybrid approach achieves a more automated classification and visualization of dynamical regimes and transitions, including in the presence of missing values, observational noise, and short time series. We illustrate the capabilities of the method through several pragmatic numerical examples. Furthermore, to demonstrate the practical usefulness of the method, we apply it to a recently published paleoclimate dataset: a speleothem oxygen isotope record from North India covering the past 5700 years. This record encodes the patterns of monsoon rainfall over the region and covers the critically important period during which the Indus Valley Civilization matured and declined. We identify a transition in monsoon dynamics, indicating a possible connection between climate change and the decline of the Indus Valley Civilization.

set. 5, 2020, 4:33am

"...species niches are conserved across space and time (niche conservatism hypothesis)...Our findings are not only relevant for predicting spatial distributions of invasive species in their exotic ranges but also for forecasting species responses to changing environments in the Anthropocene."

Chunlong Liu et al. 2020. Most invasive species largely conserve their climatic niche. PNAS first published September 3, 2020

There has been a widespread debate whether the ecological niche of species is conserved across space and time. This niche conservatism hypothesis is of high practical relevance for conserving biodiversity. Here, we synthesized empirical evidence on this hypothesis for invasive species to investigate how their climatic niche changes between their native and introduced ranges. Our results supported the hypothesis overall, but we also found important differences among taxa with different characteristics and for different types of data. Our findings are not only relevant for predicting spatial distributions of invasive species in their exotic ranges but also for forecasting species responses to changing environments in the Anthropocene.

The ecological niche is a key concept for elucidating patterns of species distributions and developing strategies for conserving biodiversity. However, recent times are seeing a widespread debate whether species niches are conserved across space and time (niche conservatism hypothesis). Biological invasions represent a unique opportunity to test this hypothesis in a short time frame at the global scale. We synthesized empirical findings for 434 invasive species from 86 studies to assess whether invasive species conserve their climatic niche between native and introduced ranges. Although the niche conservatism hypothesis was rejected in most studies, highly contrasting conclusions for the same species between and within studies suggest that the dichotomous conclusions of these studies were sensitive to techniques, assessment criteria, or author preferences. We performed a consistent quantitative analysis of the dynamics between native and introduced climatic niches reported by previous studies. Our results show there is very limited niche expansion between native and introduced ranges, and introduced niches occupy a position similar to native niches in the environmental space. These findings support the niche conservatism hypothesis overall. In particular, introduced niches were narrower for terrestrial animals, species introduced more recently, or species with more native occurrences. Niche similarity was lower for aquatic species, species introduced only intentionally or more recently, or species with fewer introduced occurrences. Climatic niche conservatism for invasive species not only increases our confidence in transferring ecological niche models to new ranges but also supports the use of niche models for forecasting species responses to changing climates.

set. 5, 2020, 9:15am

>90 margd: Fascinating, thanks!

set. 5, 2020, 9:27am

S'ha suprimit aquest usuari en ser considerat brossa.

set. 9, 2020, 7:20am

West Coast Fires:

I don’t think people are aware of how much of the west coast is burning right now: #WaWILDFIRE #OregonFires #CAfire


- Matt Zieger @mattzieger | 1:22 AM · Sep 9, 2020


Sept. 8, 2020
NOAA-NASA Suomi NPP Captures Fires and Aerosols Across America
(Click on map)

set. 11, 2020, 7:56am

Earth barreling toward 'Hothouse' state not seen in 50 million years, epic new climate record shows
Brandon Specktor | Sept 10, 2020

...the current pace of anthropogenic global warming far exceeds the natural climate fluctuations seen at any other point in the Cenozoic era, and has the potential to hyper-drive our planet out of a long icehouse phase into a searing hothouse state...

Thomas Westerhold et al. 2020. An astronomically dated record of Earth’s climate and its predictability over the last 66 million years. Science 11 Sep 2020:
Vol. 369, Issue 6509, pp. 1383-1387 DOI: 10.1126/science.aba6853

Deep-sea benthic foraminifera preserve an essential record of Earth's past climate in their oxygen- and carbon-isotope compositions. However, this record lacks sufficient temporal resolution and/or age control in some places to determine which climate forcing and feedback mechanisms were most important. Westerhold et al. present a highly resolved and well-dated record of benthic carbon and oxygen isotopes for the past 66 million years. Their reconstruction and analysis show that Earth's climate can be grouped into discrete states separated by transitions related to changing greenhouse gas levels and the growth of polar ice sheets. Each climate state is paced by orbital cycles but responds to variations in radiative forcing in a state-dependent manner.

Much of our understanding of Earth’s past climate comes from the measurement of oxygen and carbon isotope variations in deep-sea benthic foraminifera. Yet, long intervals in existing records lack the temporal resolution and age control needed to thoroughly categorize climate states of the Cenozoic era and to study their dynamics. Here, we present a new, highly resolved, astronomically dated, continuous composite of benthic foraminifer isotope records developed in our laboratories. Four climate states—Hothouse, Warmhouse, Coolhouse, Icehouse—are identified on the basis of their distinctive response to astronomical forcing depending on greenhouse gas concentrations and polar ice sheet volume. Statistical analysis of the nonlinear behavior encoded in our record reveals the key role that polar ice volume plays in the predictability of Cenozoic climate dynamics.

set. 11, 2020, 8:34am

S'ha suprimit aquest usuari en ser considerat brossa.

set. 12, 2020, 4:43am

Worth reading entire article (short). This could be a pivotal moment:

Frustrated California Governor Gavin Newsom Surveys Fire Zone, Rips “Ideological BS” Around Climate Change & “Absence Of National Leadership”
Tom Tapp | Sept 11, 2020

After touring the fire damage in the North Complex Fire near Oroville in Northern California, Governor Gavin Newsom was in no mood for one of his usual, careful media statements.

“If you do not believe in science,” Newsom said bluntly while standing in the ashes of what once was a Butte County forest, “I hope you believe observed reality.”

“The hots are getting a lot hotter and the wets are getting a lot wetter,” he observed. “The science is absolute. The data is self evident.”

“We have to own that reality and we have to own the response to that reality,” said the governor. Last year by this time, 118,000 acres had burned, he observed. This year, it’s over 3 million acres charred. The state is currently battling five of the 20 most destructive fires in the last century...

...As a result the governor announced, “We’re gonna have to fast-track our efforts in terms of meeting our clean energy goals much sooner.” He said he has asked key administration officials to “go down that list of climate change initiatives and to dust off our current processes and accelerate them across the board.”

Key among these would be to “adapt strategies to get more electric vehicles out on the street.” The state’s current goal of getting to 100% clean energy by midcentury will be “too late,” he said...

(CA Gov) Newsom details 'climate emergency' as fires rage (1:35)
Sep 11, 2020

set. 12, 2020, 5:43am

What’s causing climate change, in 10 charts
Different ways of looking at the problem.
David Roberts | Sep 11, 2020

If the question is which country currently emits the most greenhouse gas emissions, the answer is China.

If the question is which country or region emits the most greenhouse gases, the answer is ... still China, but “Other Asia” is coming up fast (even as Europe declines).

If the question is which country’s people emit the most greenhouse gases on a per-capita basis, the answer is Americans, by a fairly wide margin. (Canada and Australia also have high per-capita emissions, as do a few Middle Eastern countries...)

If the question is which region or country is responsible for the biggest portion of the greenhouse gases already in the atmosphere, for a long time, the answer was Europe ... and today it still is (with Russian and the rest of Eastern Europe included), with North America and Asia tied for second

If the question is which individual country is responsible for the most emissions, it’s the US, at almost double its nearest competitor, China.

If the question is which country or region is heading fastest in the right direction, the answer is Europe. (Look at China — is that a peak or a pause?)

If the question is which fuel has contributed most to climate change, the answer, as of the 21st century, is coal, followed by oil and natural gas.

If the question is which economic sector contributes the most greenhouse gases, the answer is electricity and heat...transport rising at a distant second. (Note that in the US, the situation is somewhat different — transportation emissions are rising and electricity sector emissions are falling. The lines recently crossed.)

...In the end, the conversation about responsibility leads where all climate conversations lead: The only hope of avoiding catastrophic damage is most every country decarbonizing as rapidly as they are capable, regardless of their histories and rivalries.

Electricity must be rapidly decarbonized to get rid of coal; heating and transportation must be rapidly electrified to get rid of oil and natural gas. Wealthy countries should mobilize to drive down the costs of clean-energy technologies through research and large-scale deployment; developing nations should work as hard as possible to substitute clean technologies when long-term industrial policy and infrastructure decisions are being made. And those with resources should help those with fewer prepare for the turbulent century to come.

Whoever’s fault it is, we either all chip in to solve it or we all suffer.

set. 13, 2020, 2:29am

A Secret Recording Reveals Oil Executives’ Private Views on Climate Change
Hiroko Tabuchi | Sept. 12, 2020

...At a discussion convened last year by the Independent Petroleum Association of America, a group that represents energy companies, participants worried that producers were intentionally flaring, or burning off, far too much natural gas...

“We’re just flaring a tremendous amount of gas,” said Ron Ness, president of the North Dakota Petroleum Council, at the June 2019 gathering, held in Colorado Springs. “This pesky natural gas,” he said. “The value of it is very minimal,” particularly to companies drilling mainly for oil.

A well can produce both oil and natural gas, but oil commands far higher prices. Flaring it is an inexpensive way of getting rid of the gas.

Yet the practice of burning it off, producing dramatic flares and attracting criticism, represented a “huge, huge threat” to the industry’s efforts to portray natural gas as a cleaner and more climate-friendly energy source, he said, and that was damaging the industry’s image, particularly among younger generations.

“What’s our message going forward?” Mr. Ness said. “What’s going to stick with those young people and make them support oil and gas?”

The recording runs 1 hour 22 minutes, opening with a moderator’s remarks and concluding with a panel discussion that covered a wide range of issues including job creation, the threats posed by solar and wind energy, and the federal leasing of oil and gas rights. The audio was provided by an organization dedicated to tracking climate policy that said the recording had been made by an industry official who attended the meeting.

set. 13, 2020, 9:12am

S'ha suprimit aquest usuari en ser considerat brossa.

set. 14, 2020, 8:49am

Climate change: Warmth shatters section of Greenland ice shelf
Jonathan Amos | 14 September 2020

A big chunk of ice has broken away from the Arctic's largest remaining ice shelf - 79N, or Nioghalvfjerdsfjorden - in north-east Greenland.

The ejected section covers about 110 square km; satellite imagery shows it to have shattered into many small pieces.

The loss is further evidence say scientists of the rapid climate changes taking place in Greenland.

...Nioghalvfjerdsfjorden is roughly 80km long by 20km wide and is the floating front end of the Northeast Greenland Ice Stream - where it flows off the land into the ocean to become buoyant.

At its leading edge, the 79N glacier splits in two, with a minor offshoot turning directly north. It's this offshoot, or tributary, called Spalte Glacier, that has now disintegrated.

...Prof Jason Box from the Geological Survey of Denmark and Greenland (GEUS)..."What makes 79N so important is the way it's attached to the interior ice sheet, and that means that one day - if the climate warms as we expect - this region will probably become one of the major centres of action for the deglaciation of Greenland."

The Northeast Greenland Ice Stream drains about 15% of the interior ice sheet...

set. 14, 2020, 5:07pm

Danny Freeman @DannyEFreeman | 3:03 PM · Sep 14, 2020:

"It'll start getting cooler, you just watch." - President Trump.

"I wish science agreed with you" - CA Natural Resources Secretary.

"I don't think science knows actually."- President Trump.

0:47 ( )

Editat: set. 18, 2020, 9:21am

Aquest missatge ha estat suprimit pel seu autor.

set. 23, 2020, 5:05pm

Climate change has been recognized as a major contributing factor for the arrival of horrific record-setting fire seasons in CA and Australia during their summers in both 2019 and 2020. It also has been related to the Covid-19 pandemic.

If people think climate change only means increased melting of icebergs and glaciers, they haven't been paying attention to the jump in severity and numbers of tropical weather events, disease outbreaks, expanding desertification, and more massive brush fires in part also attributable to the droughts produced by global warming.

Now, Stanford University scientists have calculated that these two results of climate change have combined to increase lethality among Americans due to poor air quality aggravating pre-existing conditions in some patients who contract coronavirus, resulting in higher morbidity.

Smoke from California wildfires may be factor in up to 3,000 deaths
The heavy smoke from wildfires that hung over California for just about a month may have contributed to the deaths of between 1,000 and 3,000 people, Stanford researchers said in a new report, many more people than the 26 who actually died as a direct result of the blazes.
The deaths looked at people who were 65 and older, most of whom had pre-existing medical conditions like heart disease, diabetes and respiratory ailments.
"Early evidence seems to suggest that poor air quality could worsen COVID-related outcomes, and if that's the case then our numbers above could be lower bounds."

set. 24, 2020, 8:56am

I thought eastern seaboard was most at risk fo sea rise, but on this map, Alaska has it beat!

Every Place Has Its Own Climate Risk. What Is It Where You Live?
Stuart A. Thompson and Yaryna Serkez | Sept. 18, 2020

For most of us, climate change can feel like an amorphous threat — with the greatest dangers lingering ominously in the future and the solutions frustratingly out of reach.

So perhaps focusing on today’s real harms could help us figure out how to start dealing with climate change. Here’s one way to do that: by looking at the most significant climate threat unfolding in your own backyard.

Search for your county...

(Or click on US map)

set. 24, 2020, 9:01am

Google pay 85$ per hour my last pay check was $8500 operating a hundred hours per week on-line. My younger brothers friend has been averaging 12k for months currently and he's employed concerning twenty two hours per week. I can’t believe however simple it had been once i attempted it out this is often what I do check further details by open the link and click on (HOME TECH OR MEDIA.) Click Here For More Information............

oct. 1, 2020, 8:17am

See World Economic Forum's GIF of Florida disappearing under the sea at +1-4C in 2100...
Interior of n Africa and Middle East look uninhabitable. S Asia. SE Asia...
We can't afford not to act!

The worst-case climate-change scenario could look like this. We need to avert it
Andrew Berkley | 23 Sep 2020

Experts have developed climate scenarios for the year 2100 ranging from best- to worst-case.

The Forum created a visualization of global temperature change and impacts resulting from the worst-case scenario, depicting extreme heat, rising sea levels and dramatically altered local climates.

But the worst impacts of climate change can be avoided and it's not too late.

...On the Strategic Intelligence platform, you can find visualizations and feeds of expert analysis related to Climate Change, The Great Reset and hundreds of additional topics. You’ll need to register to view.

oct. 1, 2020, 1:13pm

British Columbia’s Seamounts Are Becoming Uninhabitable
The deep ocean, where changes usually manifest over millennia, is losing oxygen at an unprecedented rate.
Judith Lavoie | October 1, 2020

In the northeast Pacific, the upper 3,000 meters of water has lost 15 percent of its oxygen over the past 60 years, and the top 500 meters is simultaneously becoming more acidic at an unprecedented rate*...

The changes, which the scientists say are a consequence of climate change, threaten the survival of the black coral, brittle stars, rockfish, and other species that live around the towering seamounts that lie off the British Columbia coast. The scientists say the seamount ecosystem—regarded as an oasis of life in the deep ocean—will be irreversibly changed, and there will likely be local extinctions.

The research shows the previously studied large oxygen minimum zone between 480 and 1,700 meters has some of the lowest oxygen levels in the global ocean, and it is expanding. The 15 percent loss of oxygen puts the northeast Pacific way above the two percent loss seen in oceans globally over the past 70 years.

The result is that the deep-sea ecosystem in the northeast Pacific is facing a double whammy: from the decrease in oxygen as the warming surface water absorbs less oxygen; and from ocean acidification, which affects the ability of marine organisms to maintain shells and skeletons...


Tetjana Ross et al. 2020. Rapid deep ocean deoxygenation and acidification threaten life on Northeast Pacific seamounts. Global Change Biology (10 August 2020)

Anthropogenic climate change is causing our oceans to lose oxygen and become more acidic at an unprecedented rate, threatening marine ecosystems and their associated animals. In deep‐sea environments, where conditions have typically changed over geological timescales, the associated animals, adapted to these stable conditions, are expected to be highly vulnerable to any change or direct human impact. Our study coalesces one of the longest deep‐sea observational oceanographic time series, reaching back to the 1960s, with a modern visual survey that characterizes almost two vertical kilometers of benthic seamount ecosystems. Based on our new and rigorous analysis of the Line P oceanographic monitoring data, the upper 3,000 m of the Northeast Pacific (NEP) has lost 15% of its oxygen in the last 60 years. Over that time, the oxygen minimum zone (OMZ), ranging between approximately 480 and 1,700 m, has expanded at a rate of 3.0 ± 0.7 m/year (due to deepening at the bottom). Additionally, carbonate saturation horizons above the OMZ have been shoaling at a rate of 1–2 m/year since the 1980s. Based on our visual surveys of four NEP seamounts, these deep‐sea features support ecologically important taxa typified by long life spans, slow growth rates, and limited mobility, including habitat‐forming cold water corals and sponges, echinoderms, and fish. By examining the changing conditions within the narrow realized bathymetric niches for a subset of vulnerable populations, we resolve chemical trends that are rapid in comparison to the life span of the taxa and detrimental to their survival. If these trends continue as they have over the last three to six decades, they threaten to diminish regional seamount ecosystem diversity and cause local extinctions. This study highlights the importance of mitigating direct human impacts as species continue to suffer environmental changes beyond our immediate control.

oct. 5, 2020, 8:46am

(2020 California wildfires double 2019 record: 1:45)

Reuters | Oct 4, 2020

Wildfires in California have burned more than 4 million acres in 2020,
over twice the previous record for any year and an area larger than Connecticut,
the state's fire agency reported on Sunday.

oct. 11, 2020, 8:32am

Emissions of Nitrous Oxide, a Climate Super-Pollutant, Are Rising Fast on a Worst-Case Trajectory
Phil McKenna | Oct 7, 2020

Emissions of nitrous oxide, a climate super-pollutant hundreds of times more potent than carbon dioxide, are rising faster than previously thought—at a rate that not only threatens international targets to limit global warming, but is consistent with a worst-case trajectory for climate change
The study, arguably the most comprehensive assessment of the global nitrogen cycle ever conducted, found that nitrous oxide (N2O) emissions caused by human activities have increased by 30 percent since 1980. Those emissions, more than two-thirds of which come from agriculture, account for nearly half of all nitrous oxide released over the past decade, with the rest coming from natural ecosystems.

Nitrous oxide is the third most important greenhouse gas after carbon dioxide and methane, and is responsible for roughly 7 percent of global warming since preindustrial times. It is nearly 300 times more potent at warming the planet than carbon dioxide, which means that even small sources of emissions can have an outsized impact on the climate.

Nitrous oxide is also the largest contributor to atmospheric ozone depletion that is not controlled by the Montreal Protocol, an international agreement developed in the 1980s to phase out ozone depleting chemicals through mandatory emissions reductions. Some policy experts say the agreement should now be extended to include nitrous oxide.

Emissions reported in the current study are in line with, or slightly higher than, a "worst case" emissions scenario by the United Nations Intergovernmental Panel on Climate Change.

Such a scenario assumes that growth in fossil fuel power production and the use of nitrogen-based fertilizer, the driving force in human-caused nitrous oxide emissions, continue unabated.

Under the worst case scenario, the world's average temperature would rise by approximately 4.3 degrees Celsius above pre-industrial times, far higher than the limit of 1.5 to 2 degrees Celsius of warming targeted in the Paris climate agreement.

...The study looked at both natural and human caused, or "anthropogenic," sources of nitrous oxide emissions as well as natural "sinks," biochemical processes that break down nitrous oxide. The study combined "bottom-up" inventories, estimates of known nitrous oxide emissions, with "top-down" assessments based on measurements of nitrous oxide concentrations in the atmosphere, from 1980-2016. Each of the past four decades had higher N2O emissions than the prior decade with some of the highest growth seen in Brazil, China and India where there have been large increases in crop production and livestock.

Curbing nitrous oxide emissions is difficult because the vast majority of anthropogenic emissions are driven by the use of nitrogen-based fertilizer, which emits nitrous oxide as it breaks down in the soil if not taken up by plants. Farmers worldwide depend on nitrogen fertilizer to increase crop production.

However, more efficient fertilizer use can curb nitrous oxide emissions. N2O emissions from agriculture in Europe decreased by 21 percent between 1990 and 2010 in response to agricultural policy that favors optimization and reduction of fertilizer use, according to the study. The policy, known as the "Nitrates Directive," was developed to protect European waters from nitrogen pollution, which causes algae blooms and "dead zones" in freshwater and marine environments and occurs when too much nitrogen fertilizer or manure is used...


Hanqin Tian et al. 2020. A comprehensive quantification of global nitrous oxide sources and sinks. Nature volume 586, pages248–256(07 October 2020)

Nitrous oxide (N2O), like carbon dioxide, is a long-lived greenhouse gas that accumulates in the atmosphere. Over the past 150 years, increasing atmospheric N2O concentrations have contributed to stratospheric ozone depletion...and climate change..., with the current rate of increase estimated at 2 per cent per decade. Existing national inventories do not provide a full picture of N2O emissions, owing to their omission of natural sources and limitations in methodology for attributing anthropogenic sources. Here we present a global N2O inventory that incorporates both natural and anthropogenic sources and accounts for the interaction between nitrogen additions and the biochemical processes that control N2O emissions. We use bottom-up (inventory, statistical extrapolation of flux measurements, process-based land and ocean modelling) and top-down (atmospheric inversion) approaches to provide a comprehensive quantification of global N2O sources and sinks resulting from 21 natural and human sectors between 1980 and 2016. Global N2O emissions were 17.0 (minimum–maximum estimates: 12.2–23.5) teragrams of nitrogen per year (bottom-up) and 16.9 (15.9–17.7) teragrams of nitrogen per year (top-down) between 2007 and 2016. Global human-induced emissions, which are dominated by nitrogen additions to croplands, increased by 30% over the past four decades to 7.3 (4.2–11.4) teragrams of nitrogen per year. This increase was mainly responsible for the growth in the atmospheric burden. Our findings point to growing N2O emissions in emerging economies—particularly Brazil, China and India. Analysis of process-based model estimates reveals an emerging N2O–climate feedback resulting from interactions between nitrogen additions and climate change. The recent growth in N2O emissions exceeds some of the highest projected emission scenarios3,4, underscoring the urgency to mitigate N2O emissions.

Editat: oct. 12, 2020, 2:16pm

A thought for Canadian Thanksgiving Day:

How affluent people can end their mindless overconsumption
Every energy reduction we can make is a gift to future humans, and all life on Earth.
Jag Bhalla and Eliza Barclay | Oct 12, 2020,

...A recent paper in Nature Communications clarifies whose actions in this moment are “central to any future prospect of retreating to safer environmental conditions.” Yes, government and industry leaders are on the hook to decarbonize operations and infrastructure. But it’s also the affluent who use far more resources than the poor — more energy and more material goods per capita than the planet can sustain.

“Highly affluent consumers drive biophysical resource use (a) directly through high consumption, (b) as members of powerful factions of the capitalist class and (c) through driving consumption norms across the population,” the authors write.

The rich or merely affluent, it turns out, are actually the ones blowing through the world’s carbon budget — the maximum amount of cumulative emissions that can be added to the atmosphere to hit the Paris agreement’s 1.5 degrees Celsius of warming goal.

According to a September report from Oxfam and the Stockholm Environment Institute, the richest 10 percent of the world’s population — those who earned $38,000 per year or more as of 2015 — were responsible for 52 percent of cumulative carbon emissions and ate up 31 percent of the world’s carbon budget from 1990 to 2015.

Meanwhile, the richest 1 percent of people — who made $109,000 or more per year in 2015 — alone were responsible for 15 percent of cumulative emissions, and used 9 percent of the carbon budget. The rapidly accelerating growth in total emissions worldwide isn’t mainly about an improvement in quality of life for the poorer half of the world’s population, either. Instead, the report finds, “nearly half the growth has merely allowed the already wealthy top 10 percent to augment their consumption and enlarge their carbon footprints.”

In sum, as the report’s lead author Tim Gore, head of climate policy at Oxfam, said in a statement, “The over-consumption of a wealthy minority is fueling the climate crisis yet it is poor communities and young people who are paying the price.”...

Yes, individual choices matter, especially if you’re affluent...

With all this in mind, here are five potential resource-responsible actions to commit to, in no particular order:

1) Drive and fly less, since the top 10 percent uses around 45 percent of land transport energy and 75 percent of air transport energy, per a 2020 paper by Steinberger in Nature Energy.

2) Retrofit your house and purchase clean energy, since roughly 20 percent of US energy-related greenhouse gas emissions come from heating, cooling, and powering households.

3) Buy food mindfully (less meat and dairy, don’t waste what you buy), since meat and dairy account for around 14.5 percent of global greenhouse gas emissions, according to the UN’s Food and Agricultural Organization.

4) Shop less, since the fashion industry generates at least 5 percent of global emissions.

5) Ditch status-signaling SUVs, since SUVs were the second-largest source of the global rise in emissions over the past decade, eclipsing all shipping, aviation, heavy industry, and even trucks.

The pleasures of much of our consumption are fast forgotten, but the costs are slow and will be felt by generations for centuries to come...

Degrowth, explained...


Thomas Wiedmann et al. 2020. Scientists’ warning on affluence. Nature Communications volume 11, Article number: 3107 (2020).

For over half a century, worldwide growth in affluence has continuously increased resource use and pollutant emissions far more rapidly than these have been reduced through better technology. The affluent citizens of the world are responsible for most environmental impacts and are central to any future prospect of retreating to safer environmental conditions. We summarise the evidence and present possible solution approaches. Any transition towards sustainability can only be effective if far-reaching lifestyle changes complement technological advancements. However, existing societies, economies and cultures incite consumption expansion and the structural imperative for growth in competitive market economies inhibits necessary societal change.Scientists’ warning on affluence

oct. 16, 2020, 4:10am

Rewild to mitigate the climate crisis, urge leading scientists
Restoring degraded natural lands highly effective for carbon storage and avoiding species extinctions
Fiona Harvey | 14 Oct 2020

Restoring natural landscapes damaged by human exploitation can be one of the most effective and cheapest ways to combat the climate crisis while also boosting dwindling wildlife populations, a scientific study finds.

If a third of the planet’s most degraded areas were restored, and protection was thrown around areas still in good condition, that would store carbon equating to half of all human caused greenhouse gas emissions since the industrial revolution.

The changes would prevent about 70% of predicted species extinctions, according to the research, which is published in the journal Nature.

Scientists from Brazil, Australia and Europe identified scores of places around the world where such interventions would be most effective, from tropical forests to coastal wetlands and upland peat. Many of them were in developing countries, but there were hotspots on every continent.

“We were surprised by the magnitude of what we found – the huge difference that restoration can make,” said Bernardo Strassburg, of the Pontifical Catholic University of Rio de Janeiro, and the lead author of the study. “Most of the priority areas are concentrated in developing countries, which can be a challenge but also means they are often more cost-effective to restore.”

Only about 1% of the finance devoted to the global climate crisis goes to nature restoration, but the study found that such “nature-based solutions” were among the cheapest ways of absorbing and storing carbon dioxide from the atmosphere, the additional benefits being the protection of wildlife...


Bernardo B. N. Strassburg et al. 2020. Global priority areas for ecosystem restoration. Nature. Published: 14 October 2020.

Extensive ecosystem restoration is increasingly seen as being central to conserving biodiversity...and stabilizing the climate of the Earth... Although ambitious national and global targets have been set, global priority areas that account for spatial variation in benefits and costs have yet to be identified. Here we develop and apply a multicriteria optimization approach that identifies priority areas for restoration across all terrestrial biomes, and estimates their benefits and costs. We find that restoring 15% of converted lands in priority areas could avoid 60% of expected extinctions while sequestering 299 gigatonnes of CO2—30% of the total CO2 increase in the atmosphere since the Industrial Revolution. The inclusion of several biomes is key to achieving multiple benefits. Cost effectiveness can increase up to 13-fold when spatial allocation is optimized using our multicriteria approach, which highlights the importance of spatial planning. Our results confirm the vast potential contributions of restoration to addressing global challenges, while underscoring the necessity of pursuing these goals synergistically.

oct. 21, 2020, 10:49am

Marina Andrijevic et al. 2020. COVID-19 recovery funds dwarf clean energy investment needs. Science 16 Oct 2020:
Vol. 370, Issue 6514, pp. 298-300. DOI: 10.1126/science.abc9697

Governments around the globe are responding to the coronavirus disease 2019 (COVID-19)–related economic crisis with unprecedented economic recovery packages (1), which at the time of writing surpassed USD 12 trillion. Several influential voices, including the United Nations (UN) secretary-general, heads of state, companies, investors, and central banks, have called for post–COVID-19 economic recovery efforts to be used to catalyze the necessary longer-term transformation toward a more sustainable and resilient society. Here we shine a light on the opportunity for these investments to support a green recovery by inventorying and classifying the latest information on governments' fiscal stimulus plans (1) and comparing the size of these measures to estimates of low-carbon energy investment needs compatible with the 2015 UN Paris Agreement. We show that low-carbon investments to put the world on an ambitious track toward net zero carbon dioxide emissions by mid-century are dwarfed by currently announced COVID-19 stimulus funds. But marked differences across countries and regions at differing stages of development emphasize the role that international support and global partnership must play to create conditions that enable a global climate-positive recovery.

Image: Economic Stimulus and Energy Investment (Global, EU, US, India, China)

oct. 22, 2020, 5:33am

Defining Moment in Human Evolution: Turbulent Era Sparked Leap in Human Behavior, Technology 320,000 Years Ago
Smithsonian | October 21, 2020

...While some scientists have proposed that climate fluctuations alone may have driven humans to evolve this remarkable quality of adaptability, the new study indicates the picture is more complicated than that. Instead, the team’s analysis shows that climate variability is but one of several intertwined environmental factors that drove the cultural shift they described in 2018. The new analysis reveals how a changing climate along with new land faults introduced by tectonic activity and ecological disruptions in the vegetation and fauna all came together to drive disruptions that made technological innovation, trading resources and symbolic communication¬–three key factors in adaptability–beneficial for early humans in this region.

...The team’s analysis suggests that as parts of the grassy plains in the region were fragmented along fault lines due to tectonic activity, small basins formed. These areas were more sensitive to changes in rainfall than the larger lake basins that had been there before. Elevated terrain also allowed water runoff from high ground to contribute to the formation and drying out of lakes. These changes occurred during a period when precipitation had become more variable, leading to frequent and dramatic fluctuations in water supply.

With the fluctuations, a broader set of ecological changes also took place. The team found that vegetation in the region also changed repeatedly, shifting between grassy plains and wooded areas. Meanwhile, large grazing herbivores, which no longer had large tracts of grass to feed on, began to die out and were replaced by smaller mammals with more diverse diets.

“There was a massive change in the animal fauna during the time period when we see early human behavior changing,” (Richard Potts, director of the Human Origins Program at the Smithsonian’s National Museum of Natural History) said. “The animals also influenced the landscape through the kinds of plants that they ate. Then with humans in the mix, and some of their innovations like projectile weapons, they also may have affected the fauna. It’s a whole ecosystem changing, with humans as part of it.”

Finally, Potts notes that while adaptability is a hallmark of human evolution, that does not mean the species is necessarily equipped to endure the unprecedented change Earth is now experiencing due to man-made climate change and Anthropogenic biodiversity loss. “We have an astonishing capacity to adapt, biologically in our genes as well as culturally and socially,” he said. “The question is, are we now creating through our own activities new sources of environmental disruption that will continue to challenge human adaptability?”

Reference: “Increased ecological resource variability during a critical transition in hominin evolution” by Richard Potts, René Dommain, Jessica W. Moerman, Anna K. Behrensmeyer, Alan L. Deino, Simon Riedl, Emily J. Beverly, Erik T. Brown, Daniel Deocampo, Rahab Kinyanjui, Rachel Lupien, R. Bernhart Owen, Nathan Rabideaux, James M. Russell, Mona Stockhecke, Peter deMenocal, J. Tyler Faith, Yannick Garcin, Anders Noren, Jennifer J. Scott, David Western, Jordon Bright, Jennifer B. Clark, Andrew S. Cohen, C. Brehnin Keller, John King, Naomi E. Levin, Kristina Brady Shannon, Veronica Muiruri, Robin W. Renaut, Stephen M. Rucina and Kevin Uno, 21 October 2020, Science Advances.
DOI: 10.1126/sciadv.abc8975

oct. 22, 2020, 8:33am

Helium is an increasingly rare element, so sodium-cooled nuke might be better pick for large scale use?

Department of Energy picks two advanced nuclear reactors for demonstration projects
Adrian Cho | Oct. 16, 2020

...The two winning designs deviate fundamentally from a conventional power reactor, which is essentially a boiler. Within the core of a nuclear reactor, atoms of uranium fuel split in a chain reaction, releasing energy and free-flying neutrons, which then split other uranium atoms. In a conventional power reactor, the energy heats highly pressurized “cooling” water that circulates through the core. Still under pressure, the cooling water flows to an external steam generator, where it boils water in a separate circuit, producing steam that drives turbines to generate electricity.

Instead of water, the 345 megawatt Natrium reactor from TerraPower, Inc., and GE Hitachi would use molten sodium metal as a coolant. Because sodium has a much higher boiling temperature than water, the coolant would not have to be pressurized, reducing the plant’s complexity and cost. The sodium would transfer its heat to molten salt, which could then flow directly to a steam generator or to a storage tank, to be held to generate steam and electricity later. In contrast to a conventional nuclear power plant, the Natrium plant could quickly ratchet up or down its total output even as its reactor continues to run steadily and efficiently. That could complement renewable sources such as wind and solar energy, which produce fluctuating power levels that need to be evened out.

In contrast, the Xe-100 design from X-Energy would use pressurized helium gas to cool its uranium-based fuel. That fuel would be packaged not in the conventional metal-clad rods, but in “pebbles”—spheres of graphite infused with countless ceramic kernels that contain the uranium. Like a giant gumball machine, the reactor would hold 220,000 pebbles, which would slowly descend through the core and, as their fuel was spent, would exit from a port at the bottom. Heated to 750°C, the helium would generate steam in a secondary circuit to produce electricity. In principle, the pebbles can’t melt, eliminating the risk of a meltdown. Each Xe-100 would generate 80 megawatts, and a plant would consist of four of the modular reactors.

Both plants should be simpler and cheaper than conventional nuclear power plants...

Both reactors would also depart from conventional designs in using a fuel that is more highly enriched in uranium-235, the fissile isotope that is key to generating a chain reaction...

As in many things nuclear, what’s old is new: Since the birth of the nuclear age in the 1950s, engineers have built a handful of sodium-cooled reactors and even a couple of pebble-bed reactors. But the devil is in the design details, and both TerraPower and X-Energy aim to make reactors that are safe and can compete with cheaper forms of power. Ultimately, TerraPower hopes to market a Natrium plant for less than $1 billion...

oct. 25, 2020, 6:22am

The Great Barrier Reef has lost 50% of its corals to climate change
Bonface Landi | Oct 15, 2020

A recent study has revealed that corals of the Great Barrier Reef have more than halved since 1995. The study, which was done by researchers from the ARC Centre of Excellence for Coral Reef Studies, warns that the Great Barrier Reef is in danger. The scientists behind the study have attributed the loss to greenhouse gas emissions. Researchers now say that if actions are not taken to reverse greenhouse gas emissions, the Great Barrier Reef may soon be unrecognizable. The research was based on an analysis of the number of corals of all sizes between 1995 and 2017...

Andreas Dietzel et al. 2020. Long-term shifts in the colony size structure of coral populations along the Great Barrier Reef. Proceedings of the Royal Society B Volume 287 Issue 1936 (14 October 2020)

The age or size structure of a population has a marked influence on its demography and reproductive capacity. While declines in coral cover are well documented, concomitant shifts in the size-frequency distribution of coral colonies are rarely measured at large spatial scales. Here, we document major shifts in the colony size structure of coral populations along the 2300 km length of the Great Barrier Reef relative to historical baselines (1995/1996). Coral colony abundances on reef crests and slopes have declined sharply across all colony size classes and in all coral taxa compared to historical baselines. Declines were particularly pronounced in the northern and central regions of the Great Barrier Reef, following mass coral bleaching in 2016 and 2017. The relative abundances of large colonies remained relatively stable, but this apparent stability masks steep declines in absolute abundance. The potential for recovery of older fecund corals is uncertain given the increasing frequency and intensity of disturbance events. The systematic decline in smaller colonies across regions, habitats and taxa, suggests that a decline in recruitment has further eroded the recovery potential and resilience of coral populations.

oct. 27, 2020, 8:41am

Geothermal energy is poised for a big breakout
David Roberts @drvoxdavid | Oct 21, 2020, 8:30am EDT

...In this post, I’m going to cover technologies meant to mine heat deep from the Earth, which can then be used as direct heat for communities, to generate electricity, or to do both through “cogeneration” of heat and electricity. (Note that ground-source heat pumps, which take advantage of steady shallow-earth temperatures to heat buildings or groups of buildings, are sometimes included among geothermal technologies, but I’m going to leave them aside for a separate post.)

...geothermal energyf...

...Getting the heat to the surface is the trick. For that purpose, it’s useful to think of geothermal energy technology as falling into four broad categories.
1) Conventional hydrothermal resources
2) Enhanced geothermal systems (EGS)
3) Super-hot-rock geothermal
4) Advanced geothermal systems (AGS)

...Geothermal power, if it can be made to reliably and economically work in hotter, drier, and deeper rock, is a perfect complement to wind and solar. It is renewable and inexhaustible. It can run as baseload power around the clock, including at night, or “load follow” to complement renewables’ fluctuations. It is available almost everywhere in the world, a reliable source of domestic energy and jobs that, because it is largely underground, is resilient to most weather (and human) disasters. It can operate without pollution or greenhouse gases. The same source that makes the electricity can also be used to fuel district heating systems that decarbonize the building sector.

...One thing that might get more people talking about geothermal is the somewhat serendipitous opportunity it offers to the oil and gas industry, which is reeling from oversupply, persistently low prices, and cratering demand caused by the pandemic. Consequently, it is hemorrhaging jobs.

Geothermal is buzzing with startups that specifically need innovation and expertise in drilling technology, the very skills many oil and gas workers already have. They could put those skills to work making the planet safer for future generations. That skills match is what animates Beard’s geothermal entrepreneurship organization and the $4.65 million contest that DOE launched this year to pair geothermal innovations with partners in the manufacturing industry.

...Geothermal remains a relatively small industry, with a market cap in the single-digit billions, while oil and gas is a trillion-dollar industry. There’s no realistic way geothermal can promise to absorb all the jobs currently being lost in oil and gas.

Nonetheless, geothermal offers O&G something it badly needs: a port in a storm. It’s a growing clean energy industry that needs a smart workforce trained in exploration and drilling. ...

oct. 28, 2020, 11:07am

Stefan Rahmstorf (Potsdam U) @rahmstorf | 8:45 AM · Oct 28, 2020:

Attention, homo sapiens, we have now left the Holocene -
the stable climate period in which you thrived, developed agriculture and built cities.
(Figure from the IPCC Special Report of 2018, )

Image ( )

oct. 29, 2020, 7:09am

"Solar climate intervention" should be understood, but hopefully we'll reduce CO2, methane, etc. emissions and NEVER need to use hail Mary pass--unanticipated, far-reaching consequences are likely, e.g., 1991 eruption if Mt Pinnatubo in Philippines affected reproduction of fish in Lake Ontario the following year.

As Climate Disasters Pile Up, a Radical Proposal Gains Traction
Christopher Flavelle | Oct. 28, 2020 climate intervention or solar geoengineering, entails reflecting more of the sun’s energy back into space — abruptly reducing global temperatures in a way that mimics the effects of ash clouds spewed by volcanic eruptions. The idea has been derided as a dangerous and illusory fix, one that would encourage people to keep burning fossil fuels while exposing the planet to unexpected and potentially menacing side effects.

But as global warming continues, producing more destructive hurricanes, wildfires, floods and other disasters, some researchers and policy experts say that concerns about geoengineering should be outweighed by the imperative to better understand it, in case the consequences of climate change become so dire that the world can’t wait for better solutions.

“We’re facing an existential threat, and we need to look at all the options,” said Michael Gerrard, director of the Sabin Center for Climate Change Law at the Columbia Law School and editor of a book on the technology and its legal implications. “I liken geoengineering to chemotherapy for the planet: If all else is failing, you try it.”...

oct. 29, 2020, 7:42am

S'ha suprimit aquest usuari en ser considerat brossa.

nov. 1, 2020, 5:12am

Dust Bowl 2.0? Rising Great Plains dust levels stir concerns
Roland Pease | Oct. 20, 2020

...dust storms on the Great Plains have become more common and more intense in the past 20 years, because of more frequent droughts in the region and an expansion of croplands. “Our results suggest a tipping point is approaching, where the conditions of the 1930s could return,” says Gannet Haller, an atmospheric scientist at the University of Utah who led the study.

The dust storms not only threaten to remove soil nutrients and decrease agricultural productivity, but also present a health hazard, says Andy Lambert, a co-author on the study and a meteorologist at the U.S. Naval Research Laboratory in Monterey, California. The dust contains ultrafine particles that can penetrate cells in the lungs and cause lung and heart disease.

...NASA satellites... remotely measure atmospheric haze due to smoke and dust... dust sensors in the region...were able to corroborate the satellite data and push the trend back more than 20 years.

...levels of wind-blown dust have doubled over the past 20 years. One clue that agriculture is responsible is that the dust levels tend to peak during spring and fall—planting and harvesting seasons, Hallar notes.

...climate change is drying out the region. Greenhouse gases are making heat waves like those in the 1930s far more likely...

Renewed agricultural expansion is adding to the problem. Grasslands are being plowed up to plant corn near refineries that turn corn into biofuels—spurred by U.S. policies that encourage renewable fuels. Soil is left exposed at critical times of the year. “Much of the expansion has been on less suitable land,” Lambert says. “It’s particularly ironic that the biofuel commitments were meant to help the environment.” Underlining the connection, Haller says the new study identifies a strong correlation between new croplands and the downwind areas where dust levels are growing the fastest.

What worries Lambert is a potential repeat of the 1930s feedbacks, where the wind-borne dust carried away vital nutrients from the soil, leading to crop losses and the need to plow up more terrain—thereby removing stabilizing ground cover and adding to the supply of dust.

Bolles has another concern. Recent research, she says, shows the worst of the dust in the 1930s came not from the fields themselves, but from marginal grasslands scattered around the plains, which perished in the deep droughts and exposed the soil to the wind. With global warming altering regional climate patterns, she once again fears for those grasslands—and is bracing for the Dust Bowl’s second coming.


Andrew Lambert et al. 2020. Dust Impacts of Rapid Agricultural Expansion on the Great Plains. GEOPHYSICAL RESEARCH LETTER
10.1029/2020GL090347 (Oct 20, 2020)

Key Points:
• Dust loading throughout the U.S. Great Plains has increased over the last two decades
• Positive correlations between cropland expansion and dust trends downwind suggest that agriculture contributed to these increases
• In the event of enhanced drought due to climate change, results support an increased risk of desertification from agricultural

Climate change and land use are altering the landscape of the U.S. Great Plains, producing increases in windblown dust. These increases are investigated by combining coarse mode aerosol observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor in addition to the Aerosol Robotic Network (AERONET) and Interagency Monitoring of Protected Visual Environments (IMPROVE) aerosol monitoring networks. Increasing trends of up to 5%/year in MODIS aerosol optical depth for dust observations are observed throughout the Great Plains (2000–2018). Cropland coverage has increased 5–10% over the majority of the Great Plains (2008–2018), and positive monthly trends in IMPROVE (1988–2018) and AERONET (1995–2018) coarse mode 90th percentile observations coincide with planting and harvesting seasons of predominant crops. Presently, results suggest increased dust due to agricultural expansion is negatively influencing human health and visibility in the Great Plains. Furthermore, results foreshadow a future where desertification becomes an increasing risk in the Great Plains.

Plain Language Summary
Throughout the U.S. Great Plains, satellite data combined with surface networks have shown a significant increase in airborne dust over the last two decades.
This airborne dust is negatively influencing human health and visibility and coincides with increases in
agricultural production.

nov. 1, 2020, 8:25am

Gorgeous, if depressing, satellite imagery:

Greenland’s Retreating Glaciers: NASA Details Physical Transformation of Over 200 Coastal Glaciers
Jet Propulsion Laboratory | October 29, 2020

...A new study of Greenland’s shrinking ice sheet reveals that many of the island’s glaciers are not only retreating, but are also undergoing other physical changes. Some of those changes are causing the rerouting of freshwater rivers beneath the glaciers, where it meets the bedrock. These rivers carry nutrients into the ocean, so this reconfiguring has the potential to impact the local ecology as well as the human communities that depend on it.

...About 80% of Greenland is blanketed by an ice sheet, also known as a continental glacier, that reaches a thickness of up to 2.1 miles (3.4 kilometers). Multiple studies have shown that the melting ice sheet is losing mass at an accelerating rate due to rising atmosphere and ocean temperatures, and that the additional meltwater is flowing into the sea.

...the new research shows that none of the 225 ocean-terminating glaciers surveyed has substantially advanced since 2000, while 200 have retreated.

...the new survey captures a trend that hasn’t been apparent in previous work: As individual glaciers retreat, they are also changing in ways that are likely rerouting freshwater flows under the ice. For example, glaciers change in thickness not only as warmer air melts ice off their surfaces, but also as their flow speed changes in response to the ice front advancing or retreating...

Twila A. Moon et al. 2020. Rapid reconfiguration of the Greenland Ice Sheet coastal margin. Journal of Geophysical Research (27 October 2020 ) DOI: 10.1029/2020JF005585

This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process

Plain Language Summary
From the 1970s through the early 1990s, the Greenland Ice Sheet was roughly in balance, with mass gains equaling mass losses. In the mid‐1990s, however, Greenland ice loss began and accelerated. By combining ~1985‐2015 records of changing outlet glacier flow, ice edge positions, and ice sheet surface elevation, we show that the margin of the Greenland Ice Sheet is undergoing a significant reconfiguration. Ice edge retreat is ubiquitous, with virtually no glaciers experiencing advance, while some areas of the ice sheet have sped up and others have slowed. Our observations reveal a rapid reconfiguration around the full ice sheet margin, with narrowing areas of fast ice flow, changes in the routing of ice flow, and glacier outlets that are likely being abandoned. The implications of rapid ice sheet reconfiguration are wide‐ranging. Water movement underneath the ice sheet likely changes, along with the quantity and timing of iceberg production and freshwater input to the ocean, affecting the nutrients and sediment transport from the ice sheet to local and regional ecosystems. Without detailed observations of earlier deglaciations and with limits on ice‐sheet computer simulation capabilities, these observational records provide an important analogue for past deglaciation and for projecting future ice loss.

The Greenland Ice Sheet has lost mass at an accelerating rate over the last two decades, but limits of early remote sensing restricted examination of localized change at an ice‐sheet‐wide scale. We use satellite‐derived ice‐sheet surface velocities, glacier terminus advance/retreat, and surface elevation‐change data spanning ~1985‐2015 to explore local characteristics of what is now a rapid reconfiguration of the ice sheet coastal margin. Widespread glacier terminus retreat is a more consistent climate response indicator than surface velocities, though local velocity patterns provide indicators of ice flow reconfiguration, including narrowing zones of fast‐flow, ice flow rerouting, and outlet abandonment. The implications of this observed rapid reconfiguration are wide‐ranging, and likely include alteration of subglacial hydrology, iceberg discharge, liquid freshwater flux, potential nutrient and sediment flux, and mass flux. Without detailed observations of earlier deglaciations and with present limits on ice‐sheet model capabilities, these observational records provide an important analogue for past deglaciation and for projecting future ice loss.

nov. 7, 2020, 5:41am

Is It Better to Plant Trees or Let Forests Regrow Naturally?
Nations are pledging to plant billions of trees. But a new study shows that we've underestimated the power of natural forest regrowth to fight climate change.
Fred Pearce | 10.31.2020

...Ecologists have traditionally dismissed the ecological gains from natural restoration of what is often called “secondary” forest. Such regrowth is often regarded as ephemeral, rarely sought out by wildlife, and prone to being cleared again. This has led many to regard planting to mimic natural forests as preferable.

Thomas Crowther, coauthor of a widely publicized study last year calling for a “global restoration” of a trillion trees to soak up carbon dioxide, emphasizes that, while nature could do the job in places, “people need to help out by spreading seeds and planting saplings.”

But a reappraisal is going on. J. Leighton Reid, director of Restoration Ecology at Virginia Tech, who recently warned against bias in studies comparing natural regeneration with planting, nonetheless told e360, “Natural regeneration is an excellent restoration strategy for many landscapes, but actively reintroducing native plants will still be a better option in highly degraded sites and in places where invasive species dominate.”

Others make the case that most of the time, natural restoration of secondary forests is a better option than planting. In her book, Second Growth, Robin Chazdon, a forest ecologist formerly at the University of Connecticut, says that secondary forests “continue to be misunderstood, understudied, and unappreciated for what they really are—young self-organizing forest ecosystems that are undergoing construction.”

Yes, she agrees, they are work in progress. But they generally recover “remarkably fast.” Recent research shows that regrowing tropical forests recover 80 percent of their species richness within 20 years, and frequently 100 percent within 50 years. That seems to be better than what human foresters achieve when trying to replant forest ecosystems.

A review of more than 100 tropical forest restoration projects by Renato Crouzeilles of the International Institute for Sustainability in Rio de Janeiro, with Chazdon as a coauthor, found that success rates were higher for secondary forests allowed to regenerate naturally than for those subjected to the “active restoration” techniques of foresters. In other words, planting can often worsen outcomes for everything from the number of bird, insect, and plant species to measures of canopy cover, tree density, and forest structure. Nature knows best.

Now, Cook-Patton has extended the reappraisal to the carbon-accumulating potential of natural forest regeneration. It too may often be superior.

This scientific rethink requires a policy rethink, says Holl. “Business leaders and politicians have jumped on the tree-planting bandwagon, and numerous nonprofit organizations and governments worldwide have started initiatives to plant billions or even trillions of trees for a host of social, ecological, and aesthetic reasons.”

She concedes that on some damaged lands, “we will need to plant trees, but that should be the last option, since it is the most expensive and often is not successful.”

Planting a trillion trees over the next three decades would be a huge logistical challenge. A trillion is a big number. That target would require a thousand new trees in the ground every second, and then for all of them to survive and grow. Once the cost of nurseries, soil preparation, seeding, and thinning are accounted for, says Crouzeilles, it would cost hundreds of billions of dollars. If natural forest growth is cheaper and better, does that make sense?


Susan C. Cook-Patton et al. 2020. Mapping carbon accumulation potential from global natural forest regrowth. Nature volume 585, pages545–550(2020)

To constrain global warming, we must strongly curtail greenhouse gas emissions and capture excess atmospheric carbon dioxide... Regrowing natural forests is a prominent strategy for capturing additional carbon..., but accurate assessments of its potential are limited by uncertainty and variability in carbon accumulation rates... To assess why and where rates differ, here we compile 13,112 georeferenced measurements of carbon accumulation. Climatic factors explain variation in rates better than land-use history, so we combine the field measurements with 66 environmental covariate layers to create a global, one-kilometre-resolution map of potential aboveground carbon accumulation rates for the first 30 years of natural forest regrowth. This map shows over 100-fold variation in rates across the globe, and indicates that default rates from the Intergovernmental Panel on Climate Change (IPCC) may underestimate aboveground carbon accumulation rates by 32 per cent on average and do not capture eight-fold variation within ecozones. Conversely, we conclude that maximum climate mitigation potential from natural forest regrowth is 11 per cent lower than previously reported3 owing to the use of overly high rates for the location of potential new forest. Although our data compilation includes more studies and sites than previous efforts, our results depend on data availability, which is concentrated in ten countries, and data quality, which varies across studies. However, the plots cover most of the environmental conditions across the areas for which we predicted carbon accumulation rates (except for northern Africa and northeast Asia). We therefore provide a robust and globally consistent tool for assessing natural forest regrowth as a climate mitigation strategy.

Editat: nov. 13, 2020, 3:55am

Changes in temperature of 4-5 degrees C are associated with extinction of ancient human species

Climate Change May Have Driven Ancient Human Species to Extinction

...For this study, the team focused on just six of the recognized Homo species: H. habilis, H. ergaster, H. erectus, H. heidelbergensis, H. neanderthalensis, and H. sapiens. They omitted others because the available fossil records were too limited for their analysis.

Using a fossil database spanning 2,754 archaeological records, the researchers mapped out where these species lived over time - linking both fossil evidence and tools associated with each species to various locations and time periods.

They also applied a statistical modeling technique called a past climate emulator that uses available records to reconstruct climate conditions, including temperature and rainfall, over the last 5 million years.

"This offers a picture of the tremendous effects that climate adversities have had," says anthropologist Giorgio Manzi.

For three of the five extinct species - H. erectus, H. heidelbergensis, and H. neanderthalensis - a sudden, strong change in climate occurred on the planet just before these species died out. Climes became colder for all three, drier for H. heildelbergensis and Neanderthals, and wetter for H. erectus. According to Raia, the change in temperature was roughly 4 to 5 degrees Celsius, on yearly averages.

The researchers further assessed just how vulnerable these species were to extinction by trying to determine their tolerance to climate change over time, using their presence in various locations as a clue to their preferred niche.

The team determined that, before disappearing, H. erectus and H. heidelbergensis lost more than half of their niche to climate change. Neanderthals lost about one-fourth. Food sources likely dwindled as habitats changed, and cold may have threatened survival for species adapted to warmer climes.

This climate explanation does not necessarily mean that other drivers of extinction weren't important too - the authors note that competition with H. sapiens, for example, could have made things worse for Neanderthals - but Raia and his colleagues believe their analysis reveals "the primary factor" in past Homo extinctions...

Pasquale Raia et al. 2020. Past Extinctions of Homo Species Coincided with Increased Vulnerability to Climatic Change. One Earth: Volume 3, ISSUE 4, P480-490, October 23, 2020. DOI:

• Climate change is a major factor in evolution, shaping the history of life on Earth
• Humans usually feel excluded by climate change-induced extinction risk
• We demonstrate that climate change drove past human species extinct

Science for Society
The message of the extinction rebellion protest movement, that human-induced climate change poses a threat to our species' survival, is reawakening consciences worldwide. Climate change is known to have been a major player in the turnover of species throughout the geological record. Were our ancestors, forged through the continually oscillating Pleistocene glacial cycles, not shielded from this danger? To date, the lack of sufficiently detailed and long-timescale climate information and the scarcity of data on early humans have left this question unanswered. By combining a mammoth data collation and analysis with novel paleoclimate modeling, we discovered that, for vanished human species, extinction had a candid, unquestionable climatic drive, which in the case of Neanderthals adds to the effect of competition with ourselves. Notably, Homo sapiens is the only species whose climatic niche was still expanding toward the end of our analysis, when the Neanderthals went extinct.

At least six different Homo species populated the World during the latest Pliocene to the Pleistocene. The extinction of all but one of them is currently shrouded in mystery, and no consistent explanation has yet been advanced, despite the enormous importance of the matter. Here, we use a recently implemented past climate emulator and an extensive fossil database spanning 2,754 archaeological records to model climatic niche evolution in Homo. We find statistically robust evidence that the three Homo species representing terminating, independent lineages, H. erectus, H. heidelbergensis, and H. neanderthalensis, lost a significant portion of their climatic niche space just before extinction, with no corresponding reduction in physical range. This reduction coincides with increased vulnerability to climate change. In the case of Neanderthals, the increased extinction risk was probably exacerbated by competition with H. sapiens. This study suggests that climate change was the primary factor in the extinction of Homo species.
...By virtue of their cognitive skills, recent human species were able to exploit a combination of fire control, clothing, and dispersal ability, that would surely have helped to mitigate the effects of climate change on their survival by effectively manipulating their own microclimates or moving rapidly to settle under better conditions. Indeed, it has been recently demonstrated empirically that such protected microclimatic conditions buffer extinction risk. Yet, not even Homo species, some of the most technologically advanced, plastic, and ecologically widespread species ever, were immune to global change. For multiple reasons, not least the spectacular advances in technologies available to shield modern humans from directly experiencing their own local climate, and the agricultural enhancement of natural primary production, our methodology cannot meaningfully be applied directly to the future of H. sapiens. But our own future depends critically on the health of Earth's supporting ecosystems and the entire living biota, and our analysis provides a stark warning concerning the power of anthropogenic future climate change to translate directly into extinction risk for other species less well equipped to adapt than sp. Homo. This suggests that the threat posed by the current, anthropogenic climate change for global wildlife and, by extension, ourselves, is possibly even more powerful than is generally appreciated.

nov. 13, 2020, 3:52am

Whether or not Earth is at risk of losing ITS 'hygropause', Mars's experience is testament to how a world can be utterly transformed.

Escape from Mars: How water fled the red planet
Mikayla MacE, University of Arizona | November 12, 2020

...when Mars is nearest the sun, the planet warms, and more water—found on the surface in the form of ice—moves from the surface to the upper atmosphere where it is lost to space. This happens once every Martian year or about every two Earth years. The regional dust storms that occur on Mars every Martian year and the global dust storms that occur across the planet about once every 10 years lead to further heating of the atmosphere and a surge in the upward movement of water.

The processes that make this cyclical movement possible contradict the classical picture of water escape from Mars, showing it is incomplete, (Shane Stone, UArizona Lunar and Planetary Laboratory, a planetary chemist) said. According to the classical process, water ice is converted to a gas and is destroyed by the sun's rays in the lower atmosphere. This process, however, would play out as a slow, steady trickle, unaffected by the seasons or dust storms, which doesn't mesh with current observations.

"This is important because we didn't expect to see any water in the upper atmosphere of Mars at all," Stone said. "If we compare Mars to Earth, water on Earth is confined close to the surface because of something called the hygropause. It's just a layer in the atmosphere that's cold enough to condense (and therefore stop) any water vapor traveling upward."

The team argues that water is moving past what should be Mars' hygropause, which is likely too warm to stop the water vapor. Once in the upper atmosphere, water molecules are broken apart by ions very quickly—within four hours, they calculate—and the byproducts are then lost to space.

"The loss of its atmosphere and water to space is a major reason Mars is cold and dry compared to warm and wet Earth. This new data from MAVEN reveals one process by which this loss is still occurring today," Stone said....


S.W. Stone et al. 2020. Hydrogen escape from Mars is driven by seasonal and dust storm transport of water. Science 13 Nov 2020:
Vol. 370, Issue 6518, pp. 824-831 DOI: 10.1126/science.aba5229

Dust storms cause Mars to lose water
Mars was once a wet planet, but it has lost most of its water through reactions that produce hydrogen, which escapes from the upper atmosphere into space. Stone et al. used data from the Mars Atmosphere and Volatile Evolution spacecraft to study how water is transported to the upper atmosphere and converted to hydrogen. They found that water can reach higher altitudes than previously thought, especially during global or regional dust storms. Photochemical modeling shows that this process dominates the current loss of water from Mars and influenced the evolution of its climate.

Mars has lost most of its once-abundant water to space, leaving the planet cold and dry. In standard models, molecular hydrogen produced from water in the lower atmosphere diffuses into the upper atmosphere where it is dissociated, producing atomic hydrogen, which is lost. Using observations from the Neutral Gas and Ion Mass Spectrometer on the Mars Atmosphere and Volatile Evolution spacecraft, we demonstrate that water is instead transported directly to the upper atmosphere, then dissociated by ions to produce atomic hydrogen. The water abundance in the upper atmosphere varied seasonally, peaking in southern summer, and surged during dust storms, including the 2018 global dust storm. We calculate that this transport of water dominates the present-day loss of atomic hydrogen to space and influenced the evolution of Mars’ climate.

nov. 14, 2020, 9:02am

On the upside Ethiopia's grain, teff, has huge diversity that may allow it to adapt to climate change.
I gather it's a staple there, but its growing reputation as a "superfood", if well managed, might benefit their economy.
Too often, global demand can crowd out local consumers though...

Scientists unlock secrets of Ethiopia's superfood in race to save it from warming climate
International Center for Tropical Agriculture (CIAT) | June 18, 2020

Teff, an ancient grain originally from Ethiopia, is a staple crop for 50 million people in the country. It is also increasingly popular worldwide, touted as a superfood for its gluten-free, high fiber and protein, and low-sugar properties.*

Yet dramatic temperature increases projected in Ethiopia by 2070, could force farmers to grow it only in mountainous areas at higher altitudes, driving down production at a time when food is already scarce and the population is rising.

Teff, however, has secrets hidden within its DNA. For the first time, scientists have mapped the grain's massive diversity, consisting of 3,850 known types. Each has unique characteristics, or "traits," allowing them to cope with different environmental conditions.

Depending on where they are grown, varieties might be heat or drought-tolerant; or produce more grain. Now, that information has been pinpointed by researchers and stored in individual "passports" for each type, which can be used to breed more resilient varieties...


Aemiro Bezabih Woldeyohannes et al, Current and projected eco-geographic adaptation and phenotypic diversity of Ethiopian teff (Eragrostis teff) across its cultivation range, Agriculture, Ecosystems & Environment (2020). DOI: 10.1016/j.agee.2020.107020

* Lidia Di Ghionno et al. Gluten-Free Sources of Fermentable Extract: Effect of Temperature and Germination Time on Quality Attributes of Teff (zucc.) Trotter Malt and Wort, Journal of Agricultural and Food Chemistry (2017). DOI: 10.1021/acs.jafc.7b01717

* Johnathon Carboni et al, Alterations in the Intestinal Morphology, Gut Microbiota, and Trace Mineral Status Following Intra-Amniotic Administration (Gallus gallus) of Teff (Eragrostis tef) Seed Extracts, Nutrients (2020). DOI: 10.3390/nu12103020

nov. 19, 2020, 10:18am

Natural refrigerants... I remember piling out of our house one night when I was five, as a neighborhood refrigerator cooled by ammonia brought in the firefighters. Fer sure there can be tradeoffs "between safety and environmental considerations"! Given the larger picture, worth engineers taking a second look, though...

A new Science Magazine Review looks at how the high global warming potential of current vapor-compression cooling equipment—perhaps the most widely used cooling technology—has led to an effort to improve it and develop more environmentally friendly refrigerants.
Mark O. McLinden et al. 2020. New refrigerants and system configurations for vapor-compression refrigeration. Science 13 Nov 2020: Vol. 370, Issue 6518, pp. 791-796 DOI: 10.1126/science.abe3692

The high global warming potential of current refrigerants in cooling equipment based on the vapor-compression cycle has triggered a major effort to find and implement more environmentally benign alternatives. Here, we review the basics of the vapor-compression cycle together with the safety, environmental, and thermodynamic constraints that have led to the current and next generation of refrigerants. The development of new fluids has focused on fluorinated olefins, known as hydrofluoroolefins (HFOs), and blends that contain HFOs. Many of these are slightly flammable, presenting trade-offs between safety and environmental considerations. Engineers also have options with a resurgence of the “natural refrigerants” (ammonia, carbon dioxide, propane, and isobutane). Innovative system designs that reduce the required quantity of refrigerant may allow a wider choice of refrigerants.

nov. 19, 2020, 12:31pm

Not an auspicious sign for fighting the ecological catastrophe!

Erin Brockovich: The president-elect has tapped a former DuPont consultant to join his Environmental Protection Agency transition board

nov. 28, 2020, 4:28pm

Giulio A De Leo et al. 2020. Schistosomiasis and climate change. BMJ 2020;371:m4324 (Published 16 November 2020) doi:

In summary, schistosomiasis transmission is expected to decrease in central areas of its current climatic location (that is, tropical Africa), because temperatures will exceed the critical thermal maximum of snails as a result of climate change. Transmission is expected to increase at the margins of the cooler range, where temperatures are currently too low for transmission. Climate change is also expected to affect risk of transmission indirectly through interactions with poverty and rural subsistence livelihoods,... lack of sewage systems, lack of access to clean water and improved sanitation, lack of affordable healthcare, increasing human movement, dam development, and agricultural expansion.

Therefore, the effect of climate change on schistosomiasis can combine with the effects from land use changes, growing human population, and subsistence livelihoods in unexpected ways. We need new research to reduce the uncertainty associated with potential shifts in the range of schistosomiasis with climate change. While addressing key research questions on climate change and schistosomiasis, decision makers, public health agencies, non-governmental organizations, and communities have several options to prepare for expected shifts in distribution of schistosomiasis caused by the compounded effect of climate and changes in land use.

Integrated surveillance and response systems need to be established in areas where models predict a high likelihood of schistosomiasis becoming endemic. Control strategies, including medical treatment and environmental interventions,... should be improved in endemic regions where transmission is expected to increase because of climate change, construction of new dams, or agricultural expansion.

Dams built in the historical range of distribution of migratory freshwater prawns, predating the snails involved in schistosomiasis transmission, should now be retrofitted with passages that allow prawns to move upstream and downstream. New dams should be designed with prawn ladders... Excessive use of fertilizers should be avoided in endemic regions, and pesticides with minimum effect on natural snail predators should be used instead... Although these interventions will not be enough to eliminate schistosomiasis, they may help limit the negative effects of climate change on schistosomiasis transmission.

Key recommendations

Invest in research to better understand the likely spread of schistosomiasis with climate change

Establish integrated surveillance-response systems in areas at risk

Increase control strategies, medical treatment, and environmental interventions in endemic regions

Ensure dams allow prawns to move along the river

Control fertilizer and pesticide use in endemic areas

nov. 28, 2020, 4:43pm

Evictions have led to hundreds of thousands of additional Covid-19 cases, research finds
Annie Nova | Nov 27 2020

Key Points
Forty-three states, plus Washington, D.C., passed a ban during the coronavirus pandemic on evictions, which at one point were estimated would displace as many as 40 million people.
New research finds that when those bans lifted, cases of the virus surged.

Expiring state eviction bans have led to hundreds of thousands of additional coronavirus cases, new research finds, raising alarm about what will happen when the national eviction moratorium lapses next month.

During the pandemic, which at one point was estimated it would displace as many as 40 million people, 43 states, plus Washington, D.C., temporarily barred evictions. Many of the moratoriums lasted just 10 weeks, while some states continue to ban the proceedings.

...researchers...found that lifting state moratoriums and allowing eviction proceedings to continue caused as many as 433,700 excess cases of Covid-19 and 10,700 additional deaths in the U.S. between March and September.

The findings are not yet published in a journal but will be available online Monday.

...If the CDC’s eviction ban isn’t extended until 2021, experts say, many new cases are likely to emerge from people being forced out of their houses and apartments...

(US Map) Renter households unable to pay rent and at risk for eviction, as a share of total renter households, July 2-7. By state:

nov. 30, 2020, 3:46pm

Krill provide a highway for ocean carbon storage (press release)
British Antarctic Survey | 27 November, 2020

Large krill swarms in the Southern Ocean could help remove additional carbon from the atmosphere, in a way that is currently ‘hidden’ in global models.

Scientists knew that the carbon-rich faecal pellets that krill produce, sink in the water column and can transfer carbon from the atmosphere to the deep ocean. In this study, a team from British Antarctic Survey found that krill moulting (shedding of the exoskeleton) could double the amount of carbon removed. The research is published today (27 November) in the journal Nature Communications.

Antarctic krill (Euphausia superba) are the main diet of whales, penguins and seals and form some of the highest concentrations of animal biomass in the world’s oceans – with over an estimated 150 million tonnes. They are also harvested for food.

This study provides the first estimate of how much carbon large swarms of Antarctic krill can draw down and store through the moulting process. The efficiency of this process has an important influence on our global climate.

...Lead author Dr Clara Manno, marine ecologist at British Antarctic Survey, says:
“This is exciting news because it almost doubles the previous estimate of how much atmospheric carbon is transported into deep ocean layers by krill. Our study reveals that large krill swarms could remove a significant amount of carbon from the atmosphere. Over the entire ocean, krill transfer 0.3 million tonnes of carbon daily – equivalent to the daily domestic CO2 emissions of the UK.”...

Continuous moulting by Antarctic krill drives major pulses of carbon export in the north Scotia Sea, Southern Ocean, Manno C, Fielding S, Stowasser G, Murphy EJ, Thorpe SE, Tarling GA, is published in the journal Nature Communications:

des. 3, 2020, 5:15am

Study Rewrites History of Ancient Land Bridge Between Britain and Europe
New research suggests that climate change, not a tsunami, doomed the now-submerged territory of Doggerland
Nora McGreevy | December 2, 2020

As recently as 20,000 years ago—not long in geological terms—Britain was not, in fact, an island. Instead, the terrain that became the British Isles was linked to mainland Europe by Doggerland, a tract of now-submerged territory where early Mesolithic hunter-gatherers lived, settled and traveled.

Doggerland gradually shrank as rising sea levels flooded the area. Then, around 6150 B.C., disaster struck: The Storegga Slide, a submarine landslide off the coast of Norway, triggered a tsunami in the North Sea, flooding the British coastline and likely killing thousands of humans based in coastal settlements...

Historians have long assumed that this tsunami was the deciding factor that finally separated Britain from mainland Europe. But new archaeological research published in the December issue of Antiquity argues that Doggerland may have actually survived as an archipelago of islands for several more centuries...

Editat: des. 3, 2020, 7:13am

I heard this 12/2/2020 on BBC World Service Radio, but so far, podcast is only available in Britain(?) Worth a listen if/when/where available:

Lecture 1: From Moral to Market Sentiments (42:00)
The Reith Lectures
2020: Mark Carney - How We Get What We Value

Mark Carney, the former Governor of the Bank of England (and before that, Canada), assesses value.
Why have financial values come to be considered more important than human ones?

des. 11, 2020, 4:21am

Great Barrier Reef has deteriorated to 'critical' level due to climate change
Julia Jacobo | December 6, 2020

The conservation status for Australia's Great Barrier Reef has declined from "significant concern" to "critical" due to increasing impacts associated with climate change...ocean warming, acidification and extreme weather, which has resulted in coral bleaching, according to the International Union for Conservation of Nature's (IUCN) 2020 World Heritage Outlook report,* which tracks whether the conservation of the world's 252 natural World Heritage sites is sufficient to protect them in the long term. The process of coral bleaching occurs when water is too warm and the algae the corals expel from their tissues cause them to turn completely white.

The decline of the coral has also resulted in decreasing populations of certain marine species, researchers found. The reef, the most extensive in the world, houses more than 1,500 species of fish.

Warming temperatures have exacerbated the spread of invasive species in the protected areas of the Cape Floral region in South Africa, and the Pantanal Conservation Area in Brazil was heavily damaged by wildfires in 2019 and 2020, according to the report. In addition, the rapid melting of the Kaskawulsh Glacier, part of Kluane Lake in the Yukon, has changed the river flow, which has led to depleting fish populations.

...In 2020, climate change remains the "most prevalent current threat," and it is assessed as a "high" or "very high" threat in 83 of 252 sites...After climate change, the next two significant threats to these natural sites are invasive alien species and tourism impacts.

In addition to the Great Barrier Reef, the islands and protected areas of Mexico's Gulf of California have also entered the critical category... It was included in the IUCN's List of World Heritage in Danger in 2019 due to the imminent extinction of endemic vaquita, which the World Wildlife Fund describes as the "world's rarest marine mammal."

There are currently 18 sites on the critical list, including the Everglades National Park in Florida and the tropical rainforest in Indonesia...

IUCN World Heritage Outlook 3
A conservation assessment of all natural World Heritage sites
November 2020
104 p

Key findings and conclusions
The IUCN World Heritage Outlook 3 builds on three cycles of Conservation Outlook Assessments undertaken since 2014. It presents the main results for 2020, but also some longer-term trends based on a comparison of three data sets now available.
■ Climate change has become the most prominent current threat. Overall, it is assessed as a high or a very high threat in 83 out of 252 sites. Climate change still remains by far the largest potential threat and is also the highest threat affecting values under all four natural criteria. This result reinforces the need for a coordinated strategy on increasing awareness, policy and action on mitigation and adaptation at the global and site levels...

des. 15, 2020, 9:57am

A $7 trillion climate change warning to the stock market from its biggest shareholder
Eric Rosenbaum | Dec 13 2020. Updated Dec 14 2020

BlackRock, which has significant influence on proxy battles against corporations, signalled this week it would support more shareholder resolutions on issues including climate change.

The world’s biggest investor has been criticized in the past for not following the words of its CEO Larry Fink, who has said climate will “fundamentally reshape finance,” with enough action.

In the past week, Exxon Mobil was targeted by activist investors and a $200 billion New York pension fund threatened to divest from fossil fuel companies...

(Investment Stewardship)
Black Rock
25 p

...For 2021, we are asking companies to demonstrate:
Board and workforce diversity consistent with local market best practice
An understanding of key stakeholders and their interests
Plans to align their business with the global goal of net zero GHG emissions by 2050...

des. 17, 2020, 2:42am

Helen Harwatt et al. 2020. Substituting beans for beef as a contribution toward US climate change targets. Climatic Change volume 143, pages 261–270 (11 May 2017)


Shifting dietary patterns for environmental benefits has long been advocated. In relation to mitigating climate change, the debate has been more recent, with a growing interest from policy makers, academics, and society. Many researchers have highlighted the need for changes to food consumption in order to achieve the required greenhouse gas (GHG) reductions. So far, food consumption has not been anchored in climate change policy to the same extent as energy production and usage, nor has it been considered within the context of achieving GHG targets to a level where tangible outputs are available. Here, we address those issues by performing a relatively simple analysis that considers the extent to which one food exchange could contribute to achieving GHG reduction targets in the United States (US). We use the targeted reduction for 2020 as a reference and apply published Life Cycle Assessment data on GHG emissions to beans and beef consumed in the US. We calculate the difference in GHGs resulting from the replacement of beef with beans in terms of both calories and protein. Our results demonstrate that substituting one food for another, beans for beef, could achieve approximately 46 to 74% of the reductions needed to meet the 2020 GHG target for the US. In turn, this shift would free up 42% of US cropland (692,918 km2). While not currently recognized as a climate policy option, the “beans for beef” scenario offers significant climate change mitigation and other environmental benefits, illustrating the high potential of animal to plant food shifts.

des. 22, 2020, 4:20am

2020 May Be The Hottest Year On Record. Here's The Damage It Did
Rebecca Hersher and Lauren Sommer | December 18, 2020
Heard on Morning Edition

...The hottest decade on record is coming to a close, with the last five years being the hottest since 1880. 2020 is just two-hundredths of a degree cooler than 2016, the hottest year ever recorded. The Earth is nearly 2 degrees Fahrenheit warmer now than it was in the 20th century...

gen. 4, 9:29am

10 steamy signs in 2020 that climate change is speeding up
Things are heating up, and not in a good way.
Tia Ghose | Jan 1, 2021

Zombie storms are rising from the dead
Arctic transformation may be permanent
Godzilla can thank climate change, too (Sahara dust storm)
A deadly hurricane season
Greenland may need new maps
The west was ablaze
Apocalyptic skies from coast to coast
Earth breaks records left and right
Massive Antarctic glacier in danger
Earth is facing a form of heat not seen in 50 million years
Lost penguin colony revealed by Antarctic melt

It's not too late

gen. 15, 4:57am

Melting icebergs key to sequence of an ice age, scientists find
Michael Bishop | Jan 13, 2020

...when the orbit of Earth around the sun is just right, Antarctic icebergs begin to melt further and further away from Antarctica, shifting huge volumes of freshwater away from the Southern Ocean and into the Atlantic Ocean.

As the Southern Ocean gets saltier and the North Atlantic gets fresher, large-scale ocean circulation patterns begin to dramatically change, pulling CO2 out of the atmosphere and reducing the so-called greenhouse effect.

This in turn pushes the Earth into ice age conditions.

As part of their study the scientists used multiple techniques to reconstruct past climate conditions, which included identifying tiny fragments of Antarctic rock dropped in the open ocean by melting icebergs.

...Over the past 3 million years the Earth has regularly plunged into ice age conditions, but at present is currently situated within an interglacial period where temperatures are warmer.

However, due to the increased global temperatures resulting from anthropogenic CO2 emissions, the researchers suggest the natural rhythm of ice age cycles may be disrupted as the Southern Ocean will likely become too warm for Antarctic icebergs to travel far enough to trigger the changes in ocean circulation required for an ice age to develop.

Professor Hall..."Likewise as we observe an increase in the mass loss from the Antarctic continent and iceberg activity in the Southern Ocean, resulting from warming associated with current human greenhouse-gas emissions, our study emphasises the importance of understanding iceberg trajectories and melt patterns in developing the most robust predictions of their future impact on ocean circulation and climate"...


Aidan Starr et al. 2020. Antarctic icebergs reorganize ocean circulation during Pleistocene glacials. Nature (Jan 13, 2021). DOI: 10.1038/s41586-020-03094-7 ,

The dominant feature of large-scale mass transfer in the modern ocean is the Atlantic meridional overturning circulation (AMOC). The geometry and vigour of this circulation influences global climate on various timescales. Palaeoceanographic evidence suggests that during glacial periods of the past 1.5 million years the AMOC had markedly different features from today...; in the Atlantic basin, deep waters of Southern Ocean origin increased in volume while above them the core of the North Atlantic Deep Water (NADW) shoaled... An absence of evidence on the origin of this phenomenon means that the sequence of events leading to global glacial conditions remains unclear. Here we present multi-proxy evidence showing that northward shifts in Antarctic iceberg melt in the Indian–Atlantic Southern Ocean (0–50° E) systematically preceded deep-water mass reorganizations by one to two thousand years during Pleistocene-era glaciations. With the aid of iceberg-trajectory model experiments, we demonstrate that such a shift in iceberg trajectories during glacial periods can result in a considerable redistribution of freshwater in the Southern Ocean. We suggest that this, in concert with increased sea-ice cover, enabled positive buoyancy anomalies to ‘escape’ into the upper limb of the AMOC, providing a teleconnection between surface Southern Ocean conditions and the formation of NADW. The magnitude and pacing of this mechanism evolved substantially across the mid-Pleistocene transition, and the coeval increase in magnitude of the ‘southern escape’ and deep circulation perturbations implicate this mechanism as a key feedback in the transition to the ‘100-kyr world’, in which glacial–interglacial cycles occur at roughly 100,000-year periods.

gen. 20, 2:02am

“There’s a powerful lesson for today. If you look at Syria and Africa, the migration out of those areas has some roots in climate change.” – Liviu Giosan

Climate Change Likely Caused Migration, Demise of Ancient Indus Valley Civilization
Woods Hole Oceanographic Institute | November 13, 2018

More than 4,000 years ago, the Harappa culture thrived in the Indus River Valley of what is now modern Pakistan and northwestern India, where they built sophisticated cities, invented sewage systems that predated ancient Rome’s, and engaged in long-distance trade with settlements in Mesopotamia. Yet by 1800 BCE, this advanced culture had abandoned their cities, moving instead to smaller villages in the Himalayan foothills. A new study from the Woods Hole Oceanographic Institution (WHOI) found evidence that climate change likely drove the Harappans to resettle far away from the floodplains of the Indus.

Beginning in roughly 2500 BCE, a shift in temperatures and weather patterns over the Indus valley caused summer monsoon rains to gradually dry up, making agriculture difficult or impossible near Harappan cities, says Liviu Giosan, a geologist at WHOI and lead author on the paper that published Nov. 13, 2018, in the journal Climate of the Past.

“Although fickle summer monsoons made agriculture difficult along the Indus, up in the foothills, moisture and rain would come more regularly,” Giosan says. “As winter storms from the Mediterranean hit the Himalayas, they created rain on the Pakistan side, and fed little streams there. Compared to the floods from monsoons that the Harappans were used to seeing in the Indus, it would have been relatively little water, but at least it would have been reliable.”...


Liviu Giosan et al. 2020. Neoglacial climate anomalies and the Harappan metamorphosis. Clim. Past, 14, 1669–1686, Nov 13, 2018.

gen. 20, 2:18am

The planet is dying faster than we thought
Brandon Specktor | Jan 15, 2021

A triple-threat of climate change, biodiversity loss and overpopulation is bearing down on Earth.

...What will that future look like? For starters, the team writes, nature will be a lot lonelier. Since the start of agriculture 11,000 years ago, Earth has lost an estimated 50% of its terrestrial plants and roughly 20% of its animal biodiversity...If current trends continue, as many as 1 million of Earth's 7 million to 10 million plant and animal species could face extinction in the near future...

Such an enormous loss of biodiversity would also disrupt every major ecosystem on the planet...

...(natural) disasters, coupled with climate-induced droughts and sea-level rise, could mean 1 billion people would become climate refugees by the year 2050, forcing mass migrations that further endanger human lives and disrupt society.

...booming (population) growth will exacerbate societal problems like food insecurity, housing insecurity, joblessness, overcrowding and inequality. Larger populations also increase the chances of pandemics...

...delay between cause and effect may be responsible for what the authors call an "utterly inadequate" effort to address these encroaching environmental threats...

The dark future described in this paper is not guaranteed, the authors wrote, so long as world leaders and policymakers start immediately taking the problems before us seriously...

But the first step is education.

"It is therefore incumbent on experts in any discipline that deals with the future of the biosphere and human well-being to … avoid sugar-coating the overwhelming challenges ahead and 'tell it like it is,'" the team concluded. "Anything else is misleading at best … potentially lethal for the human enterprise at worst."


Corey J. A. Bradshaw et al. 2021. Underestimating the Challenges of Avoiding a Ghastly Future. Front. Conserv. Sci., 13 January 2021 |

We report three major and confronting environmental issues that have received little attention and require urgent action. First, we review the evidence that future environmental conditions will be far more dangerous than currently believed. The scale of the threats to the biosphere and all its lifeforms—including humanity—is in fact so great that it is difficult to grasp for even well-informed experts. Second, we ask what political or economic system, or leadership, is prepared to handle the predicted disasters, or even capable of such action. Third, this dire situation places an extraordinary responsibility on scientists to speak out candidly and accurately when engaging with government, business, and the public. We especially draw attention to the lack of appreciation of the enormous challenges to creating a sustainable future. The added stresses to human health, wealth, and well-being will perversely diminish our political capacity to mitigate the erosion of ecosystem services on which society depends. The science underlying these issues is strong, but awareness is weak. Without fully appreciating and broadcasting the scale of the problems and the enormity of the solutions required, society will fail to achieve even modest sustainability goals...

Biodiversity Loss
Sixth Mass Extinction
Ecological Overshoot: Population Size and Overconsumption
Failed International Goals and Prospects for the Future
Climate Disruption
Political Impotence
Changing the Rules of the Game

Editat: gen. 26, 7:20am

Surging global ice melt suggest sea level rise predictions are far too conservative
Kathryn Krawczyk
Jan. 25, 2021 5:46
The Week via


Editat: feb. 3, 9:50am

COVID-19 Lockdowns Caused Cleaner Air – And Warmed the Planet
National Center for Atmospheric Research | February 3, 2021

Research shows reductions in aerosol emissions had slight, temporary warming impact.

The lockdowns and reduced societal activity related to the COVID-19 pandemic affected emissions of pollutants in ways that slightly warmed the planet for several months last year, according to a new study by the National Center for Atmospheric Research (NCAR).

The counterintuitive finding highlights the influence of airborne particles, or aerosols, that block incoming sunlight. When emissions of aerosols dropped last spring, more of the Sun’s warmth reached the planet, especially in heavily industrialized nations, such as the United States and Russia, that normally pump high amounts of aerosols into the atmosphere.

...Temperatures over parts of Earth’s land surface last spring were about 0.2-0.5 degrees Fahrenheit (0.1-0.3 degrees Celsius) warmer than would have been expected with prevailing weather conditions, the study found. The effect was most pronounced in regions that normally are associated with substantial emissions of aerosols, with the warming reaching about 0.7 degrees F (0.37 C) over much of the United States and Russia.

The new study highlights the complex and often conflicting influences of different types of emissions from power plants, motor vehicles, industrial facilities, and other sources. While aerosols tend to brighten clouds and reflect heat from the Sun back into space, carbon dioxide and other greenhouse gases have the opposite effect, trapping heat near the planet’s surface and elevating temperatures.

Despite the short-term warming effects, Gettelman emphasized that the long-term impact of the pandemic may be to slightly slow climate change because of reduced emissions of carbon dioxide, which lingers in the atmosphere for decades and has a more gradual influence on climate. In contrast, aerosols – the focus of the new study – have a more immediate impact that fades away within a few years...


A. Gettelman et al. 2020. Climate Impacts of COVID‐19 Induced Emission Changes. Geophysical Research Letters (29 December 2020) DOI: 10.1029/2020GL091805

Plain Language Summary

The COVID‐19 pandemic changed emissions of gases and particulates. These gases and particulates affect climate. In general, human emissions of particles cool the planet by scattering away sunlight in the clear sky and by making clouds brighter to reflect sunlight away from the earth. This paper focuses on understanding how changes to emissions of particulates (aerosols) affect climate. We use estimates of emissions changes for 2020 in two climate models to simulate the impacts of the COVID‐19 induced emission changes. We tightly constrain the models by forcing the winds to match observed winds for 2020. COVID‐19 induced lockdowns led to reductions in aerosol and precursor emissions, chiefly soot or black carbon and sulfate (SO4). This is found to reduce the human caused aerosol cooling: creating a small net warming effect on the earth in spring 2020. Changes in cloud properties are smaller than observed changes during 2020. The impact of these changes on regional land surface temperature is small (maximum +0.3 K). The impact of aerosol changes on global surface temperature is very small and lasts over several years. However, the aerosol changes are the largest contribution to COVID‐19 affected emissions induced radiative forcing and temperature changes, larger than ozone, CO2 and contrail effects.

feb. 3, 10:31am

" exploratory analysis of opportunities for China to alleviate debt burdens in exchange for debtor nation commitments to climate change mitigation and/or adaptation and environmental protection through “debt-for-climate” and “debt-for-nature” swaps..."

B. Alexander Simmons et al. 2021. China can help solve the debt and environmental crises. Science 29 Jan 2021:
Vol. 371, Issue 6528, pp. 468-470 DOI: 10.1126/science.abf4049


Many developing countries are experiencing mounting external debt distress owing to the economic consequences of COVID-19. G20 Finance Ministers were swift to adopt the Debt Service Suspension Initiative (DSSI) in 2020, suspending bilateral debt payments through July 2021 for 73 low-income countries. Globally, Chinese government–sponsored banks have emerged as the largest bilateral creditors. For the 46 participating DSSI countries thus far, payments due to China constitute 68% ($8.4 billion) of all official bilateral payments originally due by the end of 2020. G20 countries have now come to realize that they will need to go beyond debt suspension to include the cancellation of some portion of debt. Without substantial debt relief, developing countries will face pressure to exploit natural capital to pay short-term debt, placing conservation and climate change ambitions aside. It is therefore of paramount importance to align debt restructuring efforts with climate, biodiversity, and development goals. Although China has only recently become a major creditor, it has already built a strong record of bilateral debt relief and has begun to advocate for linking biodiversity, climate change, and international finance. Here, we conduct an exploratory analysis of opportunities for China to alleviate debt burdens in exchange for debtor nation commitments to climate change mitigation and/or adaptation and environmental protection through “debt-for-climate” and “debt-for-nature” swaps.

feb. 4, 10:01am

Canada not even mentioned in article, Scandiavian countries barely--their absence more evidence that warming Arctic will be highly contested. The US will not necessarily be the "good guy" if it avoids multilateral agreements and fora...

The Arctic Threat That Must Not be Named
Sharon E. Burke | January 28, 2021

...Here’s what the previous administration was not saying with all that passive voice and mystery: It’s climate change. Climate change is melting the ice in the Arctic. Climate change is opening up a new polar transit route. Climate change is unlocking access to oil, gas, and critical minerals under the ice. In fact, Pompeo not only wouldn’t say the words, he reportedly refused to sign the communique the Arctic Council partners had worked out because it explicitly mentioned climate change. This is more than just eliding a term he found distasteful: Climate change is the variable that will drive all other calculations in the region, whether it’s the icebreaker gap or China’s pursuit of cryospheric real estate. Not taking climate fully into account risks higher opportunity costs at best, and poor preparation for a challenging future at worst. And there is no time to waste, with troubling signs that changes in the high north may actually be much worse than previously thought...

Friction and Fisheries
Permafrost Thaws, Relationships Cool
Adapting Together

feb. 18, 10:06am

Trees keep our cities running. Urban construction is threatening their survival
Jean-Claude Ruel, professor of silviculture and urban forests, Laval University | Feb 17, 2021

...A recent study of the natural canopy in the areas covering Québec City, Beaupré, l’Île d’Orléans, Lévis and other communities along the St. Lawrence River found it generates more than $1.1 billion in annual benefits*....


* Wood, S.L.R., Dupras, J., Bergevin, C., Kermagoret, C. (2019), La valeur économique des écosystèmes naturels et agricoles de la Communauté métropolitaine de Québec et de la Table de concertation régionale pour la gestion intégrée du Saint-Laurent.Ouranos. 75 p.

feb. 22, 7:12am

Deadly floods in India point to a looming climate emergency in the Himalayas
Niha Masih and Chris Mooney | February 19, 2021

...massive flooding illustrates the risks of development in an area vulnerable to the accelerated effects of climate change: The Himalayan range, the Hindu Kush, the Tibetan Plateau and their peaks are known as the “Third Pole” because they contain the largest repository of glacial ice in the world outside the Arctic and Antarctica.

All that ice is susceptible to the warming temperatures in the region, which have outpaced the rate of global average warming in recent decades. The melting ice and expanding glacial lakes heighten the risk of landslides and floods. Environmentalists say the construction of dams and power projects and road-building development works have put millions of people in a precarious position.

...Ravi Chopra, who heads the People’s Science Institute in Dehradun, the largest city in the state, said he views the (Uttarakhand glacier) disaster as “two events.” The falling of the rock and ice mass is a natural event, he said, but as it rolled down the river, it encountered barriers like bridges and dams. The floods picked up more debris and moved with greater speed after smashing into these barriers, which he called a “man-made disaster.”

In 2013, Uttarakhand was the site of one of the worst natural disasters in the country after massive floods and landslides triggered by heavy rains killed thousands of people. In its aftermath, Chopra led a committee, following a Supreme Court order, that recommended no dams be built in “para-glacial zones” — areas where glaciers have retreated and left behind massive amounts of debris.

The two hydropower projects damaged in the latest flood are in these para-glacial zones, he said. The committee’s recommendations were challenged by developers in court. The case is ongoing...

feb. 23, 8:01am

Climate graphic of the week: Polar vortex sends Texas into deep freeze
Scientists of the atmosphere debate whether jet stream is becoming weaker and wavier
Leslie Hook and Steven Bernard February 20 2021

Avui, 6:20am

More evidence that Atlantic Meridional Overturning Circulation (AMOC) that warms Europe, etc., is slowing.
A shutdown is possible in the future as climate change continues, however steady weakening is the more likely course in the near future, as long as greenhouse gases continue to cause offsetting warming. Catch-22? :(

Scientists see stronger evidence of slowing Atlantic Ocean circulation, an ‘Achilles’ heel’ of the climate
The Atlantic meridional overturning circulation, a system of currents, is weaker than it has been in 1,000 years
Chris Mooney and Andrew Freedman | Feb. 25, 2021

...The Atlantic meridional overturning circulation (AMOC), a system of currents that includes the Florida Current and the Gulf Stream, is now “in its weakest state in over a millennium,”...experts say. This has implications for everything from the climate of Europe to the rates of sea-level rise along the U.S. East Coast.

...11 sources of “proxy” evidence of the circulation’s strength, including clues hidden in seafloor mud as well as patterns of ocean temperatures. The enormous flow has been directly measured only since 2004, too short a period to definitively establish a trend, which makes these indirect measures critical for understanding its behavior...nine out of 11 show a clear trend.

Prior research had suggested that the AMOC was at its weakest point in a millennium or more, and suggested a roughly 15 percent weakening since about 1950....

The AMOC is driven by two vital components of ocean water: temperature and salt. In the North Atlantic, warm, salty water flows northward off the U.S. coastline, carrying heat from the tropics. But as it reaches the middle latitudes, it cools, and around Greenland, the cooling and the saltiness create enough density that the water begins to sink deep beneath the surface.

The water then swings back southward and travels all the way to the Southern Hemisphere, submerged, where it makes its way to the Antarctic as part of a global system of ocean currents. The entire system is known as the ocean’s thermohaline circulation (“thermo” meaning heat and “haline,” salt), and it plays many critical roles in the climate. It is also referred to as the global ocean conveyor belt, because it redistributes heat worldwide.

In the North Atlantic, most important is the transport of heat northward, which has a moderating effect on Europe’s climate in particular. But the circulation can be weakened by making northern water more fresh and less salty, and therefore less dense. That’s what climate change — through a combination of more rain and snow, more melting of Arctic sea ice, and huge freshwater pulses from Greenland — is thought to be doing.

...scientists say that although a shutdown (of the AMOC) is possible in the future as climate change continues, steady weakening is the more likely course in the near future.

The late climate scientist Wallace S. Broecker wrote in 1997 that the AMOC is the “Achilles’ heel” of the climate system, citing evidence that it has switched on and off repeatedly over the course of Earth’s history, with the power to flip warming periods to intense cold in the Northern Hemisphere.

Scientists do not expect anything so severe in our future, especially because greenhouse gases will continue to cause offsetting warming. However, they note that even the modest slowing of 15 percent has been accompanied by odd temperature patterns in the ocean and the significant upending of certain key fisheries, such as lobster and cod off the coast of New England.

In particular, a recurrent “cold blob” has been observed in the ocean to the south of Greenland — a large region that is bucking the overall global warming trend and instead showing a marked cooling pattern. Scientists think this is evidence that less warm water is reaching this region than previously, and that it may also be a result of runoff from the melting ice sheet.

At the same time, warm water has lingered instead off the coast of the northeastern United States, where the Gulf of Maine is showing some of the fastest-warming ocean water anywhere in the world...


L. Caesar et al. 2021. Current Atlantic Meridional Overturning Circulation weakest in last millennium. NATURE GEOSCIENCE | (25 Feb 2021).

The Atlantic Meridional Overturning Circulation (AMOC)— one of Earth’s major ocean circulation systems—redistributes heat on our planet and has a major impact on climate. Here, we compare a variety of published proxy records to reconstruct the evolution of the AMOC since about ad 400. A fairly consistent picture of the AMOC emerges: after a long and relatively stable period, there was an initial weakening starting in the nineteenth century, followed by a second, more rapid, decline in the mid-twentieth century, leading to the weakest state of the AMOC occurring in recent decades.