Green Among Gray’s entire premise is faulty.

Yep, turns out my whole “just because you live in a big city doesn’t mean you can’t be green” angle is invalid, according to this Brookings Institution study that found people who live in major metro areas actually have smaller carbon footprints than those in more rural areas.

Who’da thunk?

But don’t fret dear Green Among Gray enthusiast (after 8 weeks there must be at least one of you out there, right? Hello?); even though this study calls into question the core of my mission, I’m not shaken. There are too many things still to learn. And you know what? I’m magnanimous enough that I’ll take a lesson or two from this very study.

Its seemingly counterintuitive conclusion – that the average resident in the 100 largest U.S. metropolitan areas has a smaller carbon footprint than the average American overall – is actually not so surprising when you consider:

• Mass transit: Available only in big cities. The American Public Transportation Association says mass transit reduces the nation’s carbon emissions by 37 million metric tons annually.
  
• Public awareness: Many of the lower-footprint cities on the Brookings list are in Calif., where awareness of climate-change issues is high and aggressive green legislation is widespread. It seems reasonable to assume this urban concentration of awareness extends, in a general way, throughout the country.
  

The study says the average resident in the biggest 100 metro areas emitted 2.24 tons of carbon from highway transportation and residential energy in 2005, compared with 2.6 tons of carbon emitted by the average American. To bring it home for Captivate Network viewers: Six of the 10 lowest-emitting areas on the Brookings list are Captivate markets (L.A., NYC, Seattle, San Jose, San Fran and San Diego), while there are no Captivate markets among the 10 metro areas with the largest carbon footprints.

But urbanites shouldn’t be tooting their horns (or yanking their stop indicators, as it were) too much; there’s still plenty of room for reduction.

So, city dwellers, let us know what actions you’re taking to lighten that footprint.