[throwaway0xb]

I mean tons of the last 7/10 of a mile is done by old beat up delivery trucks, with much less capacity than 18 wheelers, that idle in traffic or idle double parked in the turning lane. I'm not going to argue that cities aren't more efficient but the picture that city-dwellers (self-satisfied New Yorkers in particular) paint about their environmental and ecological impact tend to be a very narrow window of the overall impact of their choice to live there.

[dougmwne]

I'm not quite sure what you're getting at. People in urban areas have lower carbon footprints than people in car-dependent suburban and rural areas. No one has a zero or negative carbon footprint unless they do something to actively offset their emissions. I don't think most city dwellers are self-satisfied jerks. A few are, but then does it really have anything to do with the city?

Ultimately, poking people in the eye about their consumption habits is counter-productive. Cities are efficient, but not efficient enough to prevent global warming. This problem is only going to be solved through technical innovation and government regulation.