While Congress debates climate and energy legislation, local governments are moving forward. In recognition of that fact, Mother Nature Network has named seven local leaders the country’s top “Eco-mayors.”

The seven represent diverse geographic and economic landscapes, with one thing in common:

all are big-city mayors. They are Denver Mayor John Hickenlooper, New York Mayor Michael Bloomberg, San Francisco Mayor Gavin Newsom, Atlanta Mayor Shirley Franklin, Chicago Mayor Richard Daley, Houston Mayor Bill White and Seattle Mayor Greg Nickels.

In MNN’s defense, it is probably much easier to get information about the green efforts of large cities than it is to find equally compelling stories about small towns. Additionally, with their often unwieldy bureaucracies, it can be more difficult to implement effective green strategies in larger cities. Here’s the original story.

Big cities also dominated MNN’s list of the Top 10 Green U.S. Cities: 1) Portland, Ore.; 2) San Francisco; 3) Boston; 4) Oakland, Calif.; 5) Eugene, Ore.; 6) Cambridge, Mass.; 7) Berkeley, Calif.; Seattle; 9) Chicago; and 10) Austin, Texas. Clearly, California, Massachusetts and the Pacific Northwest are leading the way in the greening of the American landscape. See the story for details.

MNN is a website founded by Rolling Stones keyboardist and environmental activitist Chuck Leavell to be a “one-stop resource and an everyman’s eco-guide to environmental news, featuring breaking stories, original programs, articles, blogs, and video reports from around the country in a voice the average person can understand.”