14. Sacramento, CA

California's capital cruised into the right lane (SustainLane!) in 2007. It created a master plan for sustainability and now meticulously tracks its progress as it barrels toward its long-term goals. If we lived in Sacramento, we'd be sleeping easier -- because despite its proximity to two rivers and the Sierra Nevada Mountains, which makes us want to get outside and play, air quality is still among the worst in the nation. While there’s little the city can do about the geographical contributors, Sacramento isn’t sitting back and breathing in the smog. There are plans afoot to enhance bike infrastructure and facilities, to further increase public transit ridership, and to significantly reduce the energy consumption. Sacramento's also taking its already-proven commitment to a green economy one step further with plans to add 20,000 clean energy sector jobs by 2015.

(Photo by Hey Paul)