In 1979 Gus Speth, a Yale-trained lawyer and co-founder of the Natural Resources Defense Council (NRDC), became chair of President Carter's Council on Environmental Quality. He was 37. Approached by two scientists concerned about the rise in the earth's temperatures as a result of increased carbon emissions, Speth commissioned a study. "It created quite a stir," he says. "It got a lot of media attention.... In 1981 we knew enough that I'm quoted in the New York Times saying we ought to cap greenhouse [gases] at no more than 50 percent above the preindustrial level."

On March 2 Speth, now dean of Yale's School of Forestry & Environmental Studies, was back in Washington--this time to take part in what promised to be the largest act of climate-change civil disobedience in American history. Along with fellow environmental movement veterans Bill McKibben, Wendell Berry and NASA climatologist James Hansen; anti-coal activists from Appalachia; and some of the 12,000 student activists who had flooded Washington for the Power Shift 09 climate change conference, Speth marched to the Capitol Hill power plant, a few blocks south of the Capitol. There they blocked the five entrances and waited for the handcuffs.

The tussle over the plant is a perfect parable of the failure of our political system to respond to the threat of climate change. Built in 1904, the plant provides heat and cooling to about two dozen buildings, including the Capitol, the Supreme Court and Union Station. In 2000 the Architect of the Capitol, who oversees the physical plant, submitted a plan to replace coal, by far the worst carbon emitter of all fossil fuels, with oil or natural gas. Coal-state Senators Robert Byrd and Mitch McConnell sent a letter expressing their displeasure, and promptly secured $1 million for the Interior Department to study how to integrate new coal technologies into plant upgrades. Nine years later, despite Speaker Nancy Pelosi's plan to "green the Capitol," the plant still burns coal, the last coal-fired facility inside the DC line.

The protesters who surrounded the plant reflected the growing diversity of interests in the climate change/green jobs coalition: indigenous teenagers whose ancestral lands have been ravaged by the dirty energy economy, white grandmothers from Kentucky who have seen their communities suffocated under the toxic runoff from mountaintop removal, and young hipsters and hippies hoping for a future in green jobs. The mood was boisterous and exultant but disciplined: an exercise in cheerful, polite militancy (sample sign: Mountaintop Removal Lacks My Approval). One protester apologized to the fluorescent-vested police for having made them stay out in the cold. Margaret Stewart, who'd come from Louisville with a group of Kentuckians fighting mountaintop removal, put it this way: "We're not here to make trouble. We're here because we've tried everything else. If there were any other way to make change, we'd do it."

The crowd was so well behaved, in fact, the police decided it wasn't worth the hassle of locking them up, and made no arrests. But the action had already won its immediate demand: a few days before--thanks to some behind-the-scenes lobbying from a number of green groups--Pelosi and Harry Reid had sent a letter to the Architect of the Capitol supporting a phaseout of coal at the power plant.

It seems safe to say that the movement to stop the planet from overheating has entered its second act. Thirty years after Speth's first report, the establishment--politicians, elite media, business leaders--has finally (finally!) accepted the simple fact that burning fossil fuels is warming the planet and courting catastrophe. Now comes the hard part: doing something about it.

The political economy of Washington is so dysfunctional that there's only one way of getting large-scale progressive legislation passed: pay off the opposition. The stimulus was a case in point. This doesn't mean it was a bad bill, but the Chamber of Commerce endorsed it for a reason; the money was spread around enough to buy Big Business's acquiescence. Likewise, if we get universal healthcare, the insurance industry's grudging acceptance will likely have to be purchased, at a price.

The problem is that in the case of climate change, the interest most zealously opposed, the coal industry, cannot be bribed, because carbon reduction is incompatible with coal burning. Or, as a popular sign at the protest succinctly put it, it's Coal vs. Climate.

But climate activists find themselves victims of their own rhetorical success: they've offered such a promising picture of the clean energy future that their opponents are busy trying to crowd into the frame. From John McCain to Chevron to the coal lobby, everyone's for clean energy. (My favorite chant of the day: "Unicorns, leprechauns, clean coal!") Coal companies, like the tobacco companies before them, have adopted a strategy of obfuscation and false offers of cooperation. "They actually believe they'll be able to trick me and this generation into thinking we can unite behind them," says Jessy Tolkan, executive director of the Energy Action Coalition, which sponsored Power Shift 09. "I sat next to representatives from Duke Energy who said, 'I get you care about climate change. We care about climate change. We're partners in this fight.' My response is, I don't buy that and my generation doesn't buy that. We know that coal is not part of our clean energy future. We won't be tricked. We won't be fooled."

For the climate change movement, the demands are clear: carbon legislation this year and a moratorium on new coal plants. As Speth can attest, and as the sad story of the little Capitol power plant demonstrates, making this happen is a huge challenge. The only way it will be met is with a raw exercise of power from organized citizens. That's the thinking behind the younger generation of climate change organizers who came together from every state of the union at Power Shift 09. They were trained in lobbying over the weekend, broken up by district and, on Monday, set loose on the Hill for 378 separate meetings with Congress members and their staffs.

Emily Hawkins, who worked on Power Shift 09 and is the daughter of David Hawkins, NRDC's director of climate programs, said, "Something I heard my dad say, and a lot of people from his generation say throughout the weekend, was, 'We've been waiting thirty years for this movement to look like this, and it finally does.' And you could just see them walking around with tears in their eyes, they were so thrilled."

Outside the power plant, the crowd of 2,500 shivered in the cold, but as the hours passed, a summer grin never left Gus Speth's face. "I'm overjoyed to see this day," he told the crowd. "For those of us who worked on this for decades, haven't we been ineffectual!" he yelled with a chuckle. "We've testified, I've written four books...we've made speeches. We haven't done one thing. We haven't built a movement."