And the answer seems to be "the Bay Area." In a recent ranking by Mother nature Network, 3 Bay area cities ranked in the "greenest" top 10 in the United States. While Portland, Oregon took the number 1 spot, SanFrancisco came in at #2, Oakland at #4, and Berkeley at #7!
San Francisco was named for its goal to be America's solar energy leader, its innovative recycling program, and for being the first US city to ban plastic grocery bags, as part of its effort to divert 75% of landfill waste by 2010.
Oakland received its honor by being home to the nation's cleanest tap water, hydrogen-powered public transit and the country's oldest wildlife refuge. The port city also plans to have zero waste and be oil-independent by 2020, and already gets 17% of its energy from renewable sources.
And Berkeley is well, ....Berkeley , a leader in the incubation of clean technology for wind power, solar power, biofuels and hydropower.