The Brookings Institute just released a study which gives a snapshot of the carbon footprint of 100 metro areas in the United States. The study looked at per capita tonnage of Carbon Dioxide emissions based on transportation and residential energy usage and ranked them.

Overall, that is considering both transportation and energy usage, Pittsburgh ranked as the 34th best carbon footprint in the country, emitting, per capita, 2.276 metric tons of carbon to the atmosphere. To compare, Honolulu was the best with 1.356 metric tons, and Lexington, Ky was the worst with 3.455 metric tons.

We were naturally most interested in transportation and how the Pittsburgh Metro Area compared to the rest of the country. In this category, we ranked 24th as the smallest per capita carbon footprint, with New York City obviously taking the lead. Our footprint based on automobiles alone (excluding trucks) puts us at number 19 in the nation.

Although we haven’t pushed the numbers, there’s probably a strong correlation between the metro area carbon footprint ranking and commuting trends of the largest cities. There is no surprise that the cities with the highest percentage public transit usage are also the lowest in the carbon footprint ranking.

Click here to read a critique of the report here and get a bit more background into the report.