It is also commonly believed that leaving the city and opting for the rural life is also good for the environment. But, it's not. The per capita carbon footprint of people living in high rises is lower than those living in rural communities, primarily because in urban environments people share more resources (e.g., people who live in high-rises share the same plot of land as those above and below them; not so for folks who live in the country). And as I noted in a previous post ("Locavorism: Good for the Environment?"), it's better for the environment for people living in England to buy tomatoes grown in Spain than to grow it themselves because the energy expended to produce tomatoes in England is greater than the energy expended to produce it in Spain and ship it to England.
None of this is to suggest that pursuing practices that are good for the environment isn't a good thing; it's simply to note that some of those practices aren't as good for the environment as we often think they are.
All this and more is the subject of a recent Freakonomics podcast, "Why Bad Environmentalism Is Such an Easy Sell," which you download from iTunes or listen to at the Freakonomics website (where you can also find the transcript). It features economist Ed Glaeser, author of Triumph of the City: How Our Greatest Invention Makes Us Richer, Smarter, Greener, Healthier, and Happier. Here's a quote from Glaeser that serves as nice summary of the podcast:
I actually do believe that almost all environmentalists are motivated by relatively benign forces and they’re trying to do good for the world… But I do think that in the sales pitch, in the persuasion process, inevitably decision rules get simplified. Inevitably we move things down to sound bites, we move things down to simple implications. And sometimes these just mean that we get results that are less than perfect. In some cases we can get results that are completely the reverse of what we wanted.