The world without us

After a decade or two, nature - first plants, then wild animals - will have taken over our cities. Much to the horror of those species that depend on us for their survival, both those we've domesticated and those we consider vermin. New York City will finally be free of cockroaches, that's something, right?

After a hundred years or two, our modern concrete-and-cardboard houses will have started falling apart (if they haven't already burned down or been flooded or knocked over by earthquakes.) Our domesticated animals and plants will for the most part be extinct, replaced by species that know how to survive in the wild; horses and cats will probably make it, cows and pigs may survive on isolated islands where we've gotten rid of predators and natural competition (Hawaii, Great Britain). Some of our most celebrated feats of engineering - the Panama canal, the skyscrapers, the subway systems - will probably be destroyed.

After a few thousand years, most of our artefacts will be as invisible as the Mayan cities were before they were rediscovered a few decades ago. Some of our more well-constructed buildings and artworks - the pyramids, the great cathedrals and temples, Mount Rushmore, the Channel Tunnel, every bronze statue ever made - may still be around, even if they've started falling apart with no one to maintain them. The forests will have slowly started to spread across the world again.

After a few hundred thousand years, microbes may have evolved to eat the plastic we've left behind. CO2 levels will probably have returned to pre-1800s levels. Much of the radiation from the 400 nuclear reactors that went Chernobyl with nobody to maintain them will have dissipated. There will still be traces of the human race - both in ancient caves and ruins and in the form of chromed, stainless-steel cookware - which in a million years or two may or may not puzzle some other species which may or may not slowly start to take our place.

If we were to disappear today.

That's the basic premise that makes up The World Without Us; the human race vanishes - either instantly (raptured by a deity, kidnapped by aliens) or within a generation or two (a virus, a voluntary extinction movement). The how and why isn't really important for the thought experiment; just assume that all ~7 billion of us were suddenly gone without destroying everything else in the process. What would happen to the rest of the world?

In order to answer the question Weisman has put together an impressive picture with the help of experts from multiple disciplines, looking at our history and our present to predict a future that doesn't have us in it. Naturally, his purpose isn't to wish for the death of the human race, but to put a perspective on how we live today. And for the most part, it's a fascinating read even if he's a little too fond of details at times and there's a couple of points which are based on slightly dodgy assumptions. Up until the preachy ending he rarely takes a moral stance, just describes the impact - for better or worse - that the human race has had on the planet since we first discovered fire, and will continue to have for some time to come, along with well-founded speculations of what might happen if we suddenly left it alone. The world would do fine without us, he concludes - illustrating it most poignantly with visits to some of the very few areas in the world which humans have left alone for a few decades (ironically, usually due to war - the DMZs in Korea and Cyprus, for instance) and have quickly been reclaimed by nature. It's survived a lot worse, after all. But as long as we're its guests, we should at least be aware of when we're tracking mud over the floor.