What would happen to the planet if we were gone? As humans, we’ve all likely questioned our own mortality and this thought has probably crossed our minds. The power of nature is mighty, even more so than we can ever imagine. The next time you see weeds growing between cracks in pavement, take a closer look. Were these fragile plants really able to push their way up through a carpet of cement? Chances are that someone will come along and remedy the problem, but if no one is around to maintain it, the weeds will run wild. Now think of that scenario several times over.

[giveaway giveaway_id=1398 side=”right”]If you envisioned the Earth spinning on into eternity with little change, then you’re dead wrong. The time it would take for nature to rid the Earth of urban life may be much faster than we expected. In Alan Weisman’s The World Without Us (Thomas Dunne, 2007), he describes in detail the processes involved when humans are no longer here to keep nature at bay. His latest book, Countdown (coming in paper from Back Bay Books on May 6th), examines population control in the wake of global warming.

In The World Without Us, Weisman imagines the suburbs without humans, places where homes are swallowed up by the harsh surrounding environment. But it’s the rapid changes in store for cities that are most alarming. Take New York City, for instance. This behemoth of skyscrapers and urban development is only held together by the humans who regulate the subways, bridges and underground water systems. If we were to suddenly disappear from Manhattan, groundwater would spring up and fill the subway systems, covering all of Central Park and transforming it into marshlands. Ailanthus trees would grow in abundance, wrapping themselves around man-made materials and buckling the concrete. Bridges would begin to deteriorate and birds would flock to them DetroitIsThePlaceToBeto build nests in every available spot. New wild predators would slowly take over the city, completely ravaging domesticated dogs.

To see real examples of nature’s power, look no further than Detroit, a formerly booming industrial hub that is now utterly deserted in many places. Mark Binelli’s Detroit City is the Place to Be: The Afterlife of an American Metropolis (Metropolitan Books, 2012) provides real examples of the way that nature has overrun the city. Binelli describes “feral houses almost completely overgrown with vegetation” and “a decommissioned public school book depository in which trees had begun growing out of the piles of rotting tDetroitHouseextbooks.” In one instance, Binelli hears what he thinks is a running stream until he realizes that grasses and other vegetation have overtaken a sewer grate that is now completely hidden from view.

For more on Detroit’s destruction, check out Andrew Moore’s Detroit Disassembled (Damiani/Akron Art Museum, 2010), where old carpets turn to moss and pheasants fly from the fields behind crumbling mansions. Moore describes Detroit as a city “whose decomposition is barely comprehensible” and an area that has moved “beyond decay into a surreal landscape, where the past is receding so quickly that time itself seems to be distorted.”

Detroit DisassembledWeisman’s projection is a frightening scenario, especially since it’s a glimpse into the possible future of Detroit. Although the Motor City’s rapid decline is on a much smaller scale than Weisman’s startling descriptions of New York, the difference is we don’t have to imagine it: we’re witnessing it now.