Washington has higher mass transit usage than Chicago, for one.

Where is Seattle? A city with many walkable/livable places. A mayor who fights for making Seattle more green and leads the Kyoto protocol? Hmm…this list is bunk!

DC has the second most used subway system in the country, with somewhere around 900,000 rides per weekday last I checked. Chicago, despite being bigger and having a more extensive subway system, has far less ridership. Perhaps the many slow zones caused by deferred maintenance don’t really do much to attract ridership. As for Seattle, it has no rapid transit at all, and most people still get around by car. Even the biggest concentration of pedestrians in the city, Pike Place Market, is actually open to automotive traffic, which certainly says something about Seattle’s urban planning priorities.

My perception is that at any level of technology, there is a density tradeoff between global impacts and local impacts.

Lower density means even if a person produces more pollution, he or she is less affected by it. Higher density means people produce less pollution, in part because they don’t require private automobiles and can afford extensive sewage treatement plants, etc., but experience more pollution personally.

New Yorkers, for example, contribute less to ozone pollution than those Upstate, but experience more of it. For greenhouse gas emissions of course, NYC is by far the best in the U.S.

The two effects need to be measured and thought about separately. In part because the social and technological changes needed to reduce the global impact to those in places with less local impact are different than those required to reduce the local impact in places with less global impact.