Daniel Engber was online Sept. 13 to chat with readers about this article. Read the transcript.
Oh, if we all just disappeared. According to The World Without Us, Alan Weisman's strangely comforting vision of human annihilation, the Earth would be a lot better off. In his doomsday scenario, freshwater floods would course through the New York subway system, ailanthus roots would heave up sidewalks, and a parade of coyotes, bears, and deer would eventually trot across the George Washington Bridge and repopulate Manhattan. Nature lovers can take solace in the idea that the planet will thrive once we've finally destroyed ourselves with global warming. But Weisman takes the fantasy one step further: Let's not wait for climate change, he says. Let's start depopulating right now.
Instead of burning down our numbers with oil and gas, we might follow the advice of the founder of the Voluntary Human Extinction Movement, who tells Weisman that everyone in the world should stop having kids all at once. Weisman isn't up for quite so drastic a measure, but he makes his own pitch, moderate in comparison: Let's cut the birth rate to one child per couple, for a few generations at least. The population would dwindle by about 5 billion people over the next century, he says, ensuring the habitability of the Earth for the 1.6 billion who remained. At that point, they could all reap the rewards of a more spacious planet, sharing in "the growing joy of watching the world daily become more wonderful." It seems like a notion from the fringe, but Weisman's book has become a mainstream best seller. Could population control be the next big thing in green culture?
Nine years ago, Bill McKibben was raked over the coals for making a similar proposal in his vasectomy memoir, Maybe One. ("It's the last remaining taboo thing to talk about," he said after it was published.) Maybe times have changed. As social policy, population control seems like an infringement on fundamental human rights. That's been the case in China, where mandatory birth planning has been a ghastly failure in both moral and practical terms. But these days, we tend to think of saving the environment in terms of personal choice, rather than government programs. We're obsessed with our green lifestyles—eating local, driving hybrids, paying off our excess carbon-dioxide emissions. From that perspective, voluntary familial extinction (or at least reduction) might not be such a bad idea. If you want to reduce your carbon footprint, cutting back on kids is the best choice you can possibly make.
What's the environmental cost of having a child? In the crudest terms, you've added another version of yourself into the world, which means you're potentially doubling your carbon-dioxide emissions over the total life of your family. That's a high estimate, since our kids won't spew as much greenhouse gas as we do—automobiles, appliances, light bulbs, and everything else will become more efficient in coming generations. But these marginal improvements aren't going to make our babies carbon-neutral. They'll just contribute to global warming at somewhat lower rates than we do.
Our other green lifestyle choices can't even begin to offset the cost of adding a brand-new CO2-emitter to the population. When I ran my own numbers through Al Gore's carbon calculator, I discovered that a switch to 100 percent wind and solar power would reduce my emissions by just 1.3 tons per year. That's not even enough to account for one quarter of today's average American. Meanwhile, I'd have to do quite a bit of driving around in a Hummer H3 to mimic the environmental impact of creating another version of me. Not to mention the fact that my children might eventually decide to have their own children, who would emit even more carbon dioxide down the line.
Critics of population-based environmentalism point out that the people most likely to cut back on their baby emissions are also the ones most likely to instill their children with green values. It's the Idiocracy argument: If all the eco-conscious Americans stopped having kids, their numbers would decline. But having fewer greenies around would be a net loss for the environment only if each greenie baby did more good for the planet than harm—i.e., if the value of his or her vote exceeded the costs of his or her CO2 emissions. (If that's true, environmentalists should have as many children as possible, to stuff the ballots for Dennis Kucinich.) It's also naive to assume our children will embrace our values just because we want them to; for all our preaching, we might end up with a generation of rebellious, gas-guzzling teenagers.