Mayors Take the Lead; Cities: The federal government has been dithering on climate change and energy conservation for years. Lucky for us, America's local leaders are filling the vacuum.(Cover story)

Byline: Anne Underwood (With Matthew Philips)

Sometimes great ideas are born of desperation. For Seattle Mayor Greg Nickels, that sense of urgency developed in the winter of 2004-05, when the annual snowfall failed to materialize in the neighboring Cascade Mountains. That's a serious issue in Seattle, where melting snow feeds the city's reservoirs in the spring-time and swells the river that supplies its hydroelectric energy. Nickels's advisers were coming to him weekly with reports that the snow pack was just 1 percent of normal. "I don't think 'normal' exists anymore," Nickels remembers saying, having endured a succession of unusually warm winters. "Normal would be cause for popping champagne corks."

Nickels wasn't the only one who was starting to worry about climate change. In February 2005, 141 nations worldwide were preparing to put the Kyoto Protocol into effect--aiming to reduce global warming by cutting greenhouse-gas emissions 7 percent below 1990 levels by 2012. The United States was notably not one of them, so Nickels decided to "show the world there was intelligent life in the United States after all" by getting American cities to commit to Kyoto's targets. He drafted a document called the U.S. Mayors Climate Protection Agreement and presented it along with eight fellow mayors at the U.S. Conference of Mayors in March 2005. Their goal: to have 141 of their colleagues sign within a year, equaling the number of foreign countries that were party to Kyoto.

Two years later, a maverick idea has blossomed into a movement. To date, 435 mayors have signed on, Republican and Democratic, in Red States and Blue, from the crunchy coasts to the conservative heartland. Some of them govern cities with longstanding records of environmental activism, such as Chicago, San Francisco and Portland, Ore. But their ranks also include recent converts like conservative Republican Robert Cluck of Arlington, Texas, and Tom Barrett of Milwaukee, who just two years ago said it would be hard for him to join because of his city's commitment to promoting industry. Their combined efforts are now far more than symbolic. "These cities represent 61 million people," says Nickels. "That's equivalent to ...