I've always been wary of city sustainability rankings (Warren Karlenzig's top-notch How Green Is Your City? excepted). A recent Brookings Institution report of the carbon emissions of the 100 largest U.S. cities is a case in point.
I've always been wary of city sustainability rankings (Warren Karlenzig's top-notch How Green Is Your City? excepted). A recent Brookings Institution report of the carbon emissions of the 100 largest U.S. cities is a case in point:
The city with the lowest per capita carbon footprint? Honolulu, Hawaii. Honolulu, which owes its modern existence to the hugely carbon intensive international airline system that makes Hawaii's tourism-dependent economy possible.
Brookings certainly does a fine job in the report itself. Quantifying the carbon emissions of the 100 largest American cities is no easy task, and the report considers carbon sources by sector and specific use, as well as underlying factors like land use patterns and transportation policies. But the report also acknowledges that many outside factors, like climate and primary electricity source, have an enormous effect on a given metro area's carbon emissions.
Ultimately, the ranking is a vehicle for Brookings to make some important statements on what the U.S. should do to reduce its overall footprint: introduce energy-efficient freight operations, use federal housing policy to push energy-efficient land use, and other long-overdue ideas. The fact that remote Honolulu comes out on top simply underlies the complexity of determining not just how to meaningfully measure our carbon emissions, but how to craft federal and local policy to reduce them.
One lesson: we can't just look to the city with the smallest footprints and ask what they did right. We need to understand the complex economic and ecological contexts in which those cities operate -- and, even more importantly, understand how those contexts will change thanks in a world of carbon constraints and expensive energy.
PHOTO: Honolulu, HNL runway 8R by kla4067