Look back a hundred million years to the mid-Cretaceous period: how accurate a picture of that world do we have today? Well, we know quite a bit about its marine life (shallow seas, which were widespread then, are by far the best environments for the preservation of fossils), but our knowledge of the deep oceans and of life on land is a lot more patchy. Take dinosaurs as a good example: we know a decent amount about lowland species, but comparatively nothing about those of the uplands and mountains.
    Now go forwards by the same amount: what sort of picture of our world, of 21st-century Earth, would future palaeontologists have? In particular, would they even know that Homo sapiens had been here at all? Your immediate reaction might be to think of all those millions of square miles of concrete and tarmac, of all the gigantic constructions—both above and below ground: well of course they'd know we'd been here! But, in fact, it's not quite the obvious question it seems at first—the year 100,000,000 A.D. is mind-numbingly remote. In the interim there would have been both the building and eroding away of entire mountain ranges; the planet's crust would have been crumpled, faulted, melted; there may have been large-scale volcanism, major changes in sea level and encroachments of the polar ice caps. Would any traces of our civilisation really survive all this—and, if so, what exactly? What would the surviving artefacts actually look like?
    This is a super topic for a book—but The Earth After Us just doesn't get to grips with it. It begins well enough, setting the idea up: alien scientists land on Earth a hundred million years from now and, as a whole series of geological anomalies gradually comes to light, realisation dawns that something unusual may have happened here in the distant past. Unfortunately, the author then largely abandons this idea in favour of a textbook: we get overviews of stratigraphy, plate tectonics, palaeontology and so on—which would be fine (I love geology) except that that's not the book I thought I'd be reading. Even when we do return to the subject during the final couple of chapters, it's still not dealt with in anywhere near enough detail. The feeling I had while reading this book is that, while well written and factually very good, what it suffers from is a fatal lack of imagination. A frustrating read overall.

( )

If aliens visited the Earth 100,000,000 years from now, long after humanity has passed away, would they be able to detect any signs that we were ever here at all? The answer is yes, but much less than you might think. They'd have to really be looking, and to know exactly what they were doing, and even then, the record would be hard to piece together and would leave an awful lot out. At the very least, they could learn from the geologic record that there was an odd little warming period that didn't fit the usual pattern of Earth's warming and cooling cycles, but they might or might not ever understand what caused it.

I find this question, and its possible answers, fascinating. Contemplating this really gives one a sense of the vastness of geologic time, and how fleeting human timescales are in the scheme of things. Thinking about how little will be left of us a hundred millions years from now also brings home just how little we can actually know of the world of a hundred million years ago. How many creatures were alive then that we will never find fossils of at all?

So, the parts of this book that dealt directly with the question in the title were really interesting to me. Unfortunately, there was a lot of the book that didn't. I had the feeling I was in trouble when, skimming over the acknowledgements, I saw the author explain the idea behind it: "to explain the workings of stratigraphy through the future of humankind and the fruits of its industry." That is basically what he does: uses this question as a launching point to talk about geology and the science of how we understand the history of geology, complete with very long explanations of things like exactly how new seafloor is formed. But, I have to say, while I find geology interesting in theory, the details of it quickly get boring to me. What I was hoping for, really, was a book that would explain the fossilized future of humanity via the workings of statigraphy, and not vice versa.

For those who are interested both in pondering the question of the title and getting some detailed lessons on geology, though, it may be more interesting overall. ( )

Wonderful extended time perspective of the place that humanity will occupy in the evolving history of Earth. Told from the non-intrusive perspective of alien visitors who endeavour to reconstruct a history of humanity from fossil traces, 100 million years hence. Packed with illuminating detail. Don't bother if you don't have an intelligent amateur's interest in basic geology, chemistry and physics. ( )

A look into what evidence would be left behind by our civilization if an alien race were to discover and explore earth 100 million years into the future. An interesting account of what fossils would be left behind to tell the story of the human race. ( )

This book was better than bad. ( )