Moving from a suburb or rural area to a city can reduce your carbon emissions by up to 70 percent. And — good news! — a lot of people would like to move to big cities. But they can’t, because the people currently living in the cities refuse to allow more development. They like their city the way it is, thankyouverymuch. You can see the environmental impact of that on this graph: D.C. has abnormally high per-capita carbon emissions for a city — almost triple New York’s level. Why? I’m guessing it’s the height limit we impose on buildings, which encourages sprawl and high prices rather than density and low emissions.

The irony, as Ryan Avent notes with some annoyance, is that a lot of the city-dwellers walking the picket lines against tall buildings and changes to a city’s “character” think of themselves an environmentalists. Kevin Drum comments:

My guess is that virtually nobody in the country thinks that cities are greener places than towns or suburbs. And by “virtually nobody,” I mean maybe a few percent tops. For most people, it’s wildly counterintuitive on all sorts of levels to think of big, dirty, crowded, urban areas as “green.” It just doesn’t compute.

The downside of this is that urbanophiles have a huge uphill battle ahead of them to change people’s minds. The upside is that there’s no place to go but up. It might take years or decades, but there’s a genuine opportunity to educate the public over the long term and change the way they think about density. And this in turn represents a genuine opportunity to change the way Ryan’s lefty friends think about developers who want to put up dense new buildings.