Cities Are Cleaner Than Suburbs

"On a pleasant April day in 1844, Henry David Thoreau-the patron saint of American environmentalism-went for a walk along the Concord River in Massachusetts. With a friend, he built a fire in a pine stump near Fair Haven Pond, apparently to cook a chowder. Unfortunately, there hadn't been much rain lately, the fire soon spread to the surrounding grass, and in the end, over 300 acres of prime woodland burned. Thoreau steadily denied any wrongdoing. "I have set fire to the forest, but I have done no wrong therein, and now it is as if the lightning had done it," he later wrote. The other residents of Concord were less forgiving, taking a reasonably dim view of even inadvertent arson. "It is to be hoped that this unfortunate result of sheer carelessness, will be borne in mind by those who may visit the woods in future for recreation," the Concord Freeman opined.

Thoreau's accident illustrates a point that is both paradoxical and generally true: if you want to be good to the environment, stay away from it. Move to high-rise apartments surrounded by plenty of concrete. Americans who settle in leafy, low-density suburbs will leave a significantly deeper carbon footprint, it turns out, than Americans who live cheek by jowl in urban towers. And a second paradox follows from the first. When environmentalists resist new construction in their dense but environmentally friendly cities, they inadvertently ensure that it will take place somewhere else-somewhere with higher carbon emissions. Much local environmentalism, in short, is bad for the environment."