1. Distant Terrestrial Future We often talk about letting nature back into the modern metropolis, but what happens if we look at this process over a far larger timescale-say, over the course of l00 million years? Geologist and popular-science writer Jan Zalasiewicz explores the extremely distant terrestrial future in his poetic and thoroughly stimulating new book The Earth Af ter Us. Zalasiewicz is refreshingly blunt in his assessment of humankind's chances of long-term preservation.
The surface of the future Earth,
he writes,
one hundred million years from now, will not have preserved evidence of contemporary human activity. Fair enough. He adds, however, that in that distant era-as far from the present as we are now from the dinosaurs-there will still be subtle proof that humans once walked the earth. After all, some of our cities will actually fossilize. Zalasiewicz explained the basics to Dwell:
I think we have a good idea, at least for the short to medium term, which cities have a chance of being fossilized,
he begins. That is because we have a reasonable idea of which bits of the Earth's crust are sinking and which bits are going up-and those cities being carried upward by plate tectonics will be eroded. No part of them will survive.
San Francisco and Los Angeles, that is, will be erased. entirely, and those cities getting pushed down?
Once a city is buried and beneath the reach of waves, the process of fossilization will begin,
Zalasiewicz says. He suggests that cities close to coasts and slow rivers will, sooner or later, be buried, and it is burial that allows for fossilization. Cities like New Orleans, Hanoi, Shanghai, Venice and Amsterdam might thus survive
at least for a few million years into the future.
As he writes in The Earth After Us,
Our drowned cities and farms, highways and towns, would begin to be covered with sand, silt, and mud, and take the first steps toward becoming geology.
Next time you are out walking across our many roads and parking lots, through shopping malls and homes, it might be worth taking a second look: All of this might yet be squeezed thin into some strange new sandstone and transformed into a permanent part of the future Earth.