The Seattle Department of Transportation has put together a handy map (via Orphan Road) that shows that the city's densest areas (downtown, South Lake Union, lower Queen Anne, and pockets of north Seattle) have the lowest greenhouse-gas emissions in the city, thanks largely to the fact that people in dense areas drive less than people who live in single-family neighborhoods (to say nothing of Seattle's sprawling suburbs). For density enthusiasts, this may be an obvious point, but for others, it's worth repeating once more, with feeling; as Dan pointed out yesterday, the negative externalities of car culture (deaths in traffic accidents, air pollution, loss of habitat to sprawl, etc.) far outweigh the benefits of driving.