You remember John Kerry, right? Tall, silver-haired, urbane enough to be accused of being French. But there’s a feisty side to the senior senator from Massachusetts, and it was on display at a forum on energy and economic growth, where Kerry teed off on congressional Republicans and others who doubt the seriousness of the challenge of climate change.

“After a while you get exasperated and jaded and frustrated about it all,” Kerry told The New Republic forum at the National Press Club. “I’ve had it just about up to here with America’s indifference to the realities of this crisis … the United States is like an ostrich putting its head in the sand.”

How do you feel about the U.S. political establishment, Senator Kerry? “I don’t know what’s happened to us in the body politic of this country where facts and science seem to be so easily shunted aside and disposed of in favor of simple sloganeering, pure ideology and little bromides of politics that are offered up, that offer no solution to anything but might get you through an election.”

Your Republican colleagues in Congress? “In the Republican party … about half the class that came in (to Congress) this year doubts that humans have anything to do with climate change or that climate change is happening … The Flat Earth Caucus is growing.”

How about the billionaire Koch brothers? “The Koch brothers are funding a lot of efforts to prevent us from doing anything (about climate change). They funded this climate doubters Berkeley study in the hopes that one study out of thousands would … show that all the rest of this stuff is fabricated ideological bunk from the left.” (As it turned out, and as Kerry noted, the Berkeley Earth Science Project agreed with most other studies that climate change is occurring and human activities fuel it.)

Kerry said he was troubled that China is now “winning the clean energy race,” with Germany second and the United States slipping to third.

“I think America’s greatness, America’s capacity to lead, is really on the line,” he said. “And I see it and feel it as chairman of the Foreign Relations Committee in the many conversations I have with leaders in various parts of the world … I just see them and feel them doubting our resolve, doubting our capacity, doubting whether we’ll really be there in almost anything … whether our political system will let it happen.”

The near-shutdown of the U.S. government last week didn’t help, he said.

Kerry’s impassioned words were especially striking after the light-hearted introduction he gave himself.

“I gather I wasn’t your first choice,” he told the well-heeled, soberly-dressed crowd. “Charlie Sheen couldn’t be here.”

Photo credits: REUTERS/POOL (Senator John Kerry in Caesarea, Israel, March 22, 2011)

REUTERS/Chaiwat Subprasom (Greenpeace activists hold cutouts portraying extreme weather caused by climate change during a demonstration in front of the United Nations building, venue of this year’s climate talks, in Bangkok April 4, 2011)

REUTERS/Rick Wilking (Actor Charlie Sheen gestures toward the media as he leaves the Pitkin County Courthouse after his sentencing hearing in Aspen, Colorado August 2, 2010)