Once we got past the top three, we began to do a little head-scratching. Top 10 cities Philadelphia and New York made another top 10 list this year: the top 10 most polluted cities as ranked by the American Lung Association. In the next tier, we found that Albuquerque, Tuscon, Phoenix and Los Angeles all made the top 25, and Las Vegas was close behind at #27. Given all of these cities' reputations for massive amounts of sprawl and water consumption, their placement seemed... well... interesting. Looking at SustainLane's very thorough overview of its methodology gave us a better sense of how and why some cities fared as well as they did.First, the only criteria for inclusion in the survey was the size of a city's population, so while the folks at SustainLane chose urban areas that represent a large proportion of the US' overall population, they immediately ruled out smaller cities, like Burlington, VT, and Durham, NC, that are doing wonderful things but didn't make the cut because of their size. Despite their relatively wasteful ways, Southwestern cities had to be included in the rankings simply because they're huge centers of (largely unsustainable) growth. More importantly, though, one of the survey's primary methodological criterion was "Data or information sets that would be of relatively equal importance to cities across the United States. For example, water conservation programs were not included because they would be much more important for a desert city in the Southwest than for a city with a plentiful water supply." While this makes for a much cleaner comparison between urban centers, it also ignores one of the fundamental tenets of sustainable development: adapting to the natural environment as it is. There's no doubt that attempting to weigh cities by the unique features of their environment makes for a much more difficult comparison; at the same time, a city embarking on a truly sustainable path is not one that does what all other cities are doing, but rather one that takes a look at its own natural environment and figures out how to live within it as lightly as possible.
We certainly don't mean to dismiss SustainLane's rankings outright -- cities like Portland and San Francisco are making tremendous strides in addressing their ecological footprints, and it's important to take note of and applaud these efforts. We would certainly hope, though, that in future surveys, the folks at SustainLane, as well as others publishing such rankings, make a greater effort to incorporate the diversity of ecosystems small and large into their methodology, and to choose cities by multiple criteria. Perhaps it's not even necessary to rank cities, but to simply recognize those taking genuinely sustainable steps forward. Boston and Phoenix can both make sincere efforts towards improving their environmental quality and preserving the resources on which they depend, but if they both take the same steps, at least one will probably not make much progress. And Durham may outdo them both... :: The SustainLane 2006 US City Rankings