Imagine an earth without humans. The how or why doesn't matter -- just poof . We die from disease or simply wink out. The premise of science writer Alan Weisman's The World Without Us is frankly delicious. Okay, sorry, I meant disturbing. Illuminating? Humbling? Insidious? In truth, I am not sure how I feel -- except completely hooked.
Much of the book is concerned with the things we leave behind. What, for example, happens to New York City? Without humans to pump the subways dry, the city floods. Sewer lines plug, pipes burst, streets become rivers. Even skyscrapers topple in this waterlogged mess. In about 300 years, all the bridges have collapsed. Moose and bear swim over to explore a forest of oak and beech. Rats and roaches, which relied on people for food and shelter in the bitter New York winters, are long gone. In New York, as elsewhere in the world, most domesticated animals and plants fail to survive in our absence. Feral cats, however, do just fine.
Our greatest monuments -- the Hoover Dam and the Panama Canal -- disappear with surprising ease. Plastic is another story. Over the course of 50 years, we have produced more than one billion tons of the stuff. It is all still here, notably in the oceans, where instead of chemically biodegrad-ing, plastic physically breaks down into ever-smaller pieces, bite-size chunks for larger fish and fine particles for zooplankton. No one knows how this will affect the food chain; we can only surmise that the consequences will be long-term. In a world without us, plastic remains our legacy.
Nuclear power plants share that honor. There are 441 on earth right now. Unmanned, they soon overheat. About half burn and the rest melt, spilling radioactivity into the air and nearby bodies of water. The resulting 441 "hot spots" will contaminate the planet for thousands of years. The good news is that, without us, the 30,000 nuclear warheads we leave behind will never be detonated.
Despite this formidable release of radioactivity, despite the chance that we may have already caused runaway global warming, The World With-out Us can seem perversely optimistic. Without us, the world will recover from us. No more overfishing. No more dumping of phosphates and nitrates into fields and rivers. No more tearing down mountains for coal. No more pollution from burning fossil fuels. Without us, the oceans fill again with abundant life. Rare animals like the Siberian tiger and red-crowned crane return.
Not only does nature rush in with her oaks, beeches, tigers, moose, and bear; she also has more subtle powers. Consider the voles that live exposed to the radiation still emanating from the Chernobyl site. According to the biologists whom Weisman interviewed, these animals now mature, breed, and die more quickly than unexposed members of the same species. Weisman writes that this speeded-up selection may be "upping the chances that somewhere in the new generation of young voles will be individuals with increased tolerance to radiation." And one day -- say in 100,000 years -- a bacterium will evolve that can eat plastic, suggests one evolutionary biologist.
Weisman acknowledges what an earth without humans would lack: the unique creativity and consciousness that is the source of our music and art, our spirituality, our family life. But he doesn't spend much time grieving.
The World Without Us is a glimpse of an arguably healthier world -- and implied in that vision is a call to action. At the end of this thought experiment, Weisman suggests that since humans are not about to wink out soon, we should at least agree to get smaller, by limiting popu-lation growth and using fewer resources. This would take us closer to what we really want: to live in that world without us.
-- Sharman Apt Russell