Former President Bill Clinton and the Democratic presidential candidates rushed to applaud Gore. Sen. Hillary Rodham Clinton, N.Y., praised his "dedication and tireless work," while Sen. Barack Obama, Ill., called him "an extraordinary leader" who had "advanced the cause of peace ... around the world."

White House spokesman Tony Fratto described the president as happy for Gore and the U.N. panel. "Obviously it's an important recognition and we're sure the vice president is thrilled," he said.

Sen. John McCain, R-Ariz., who supports measures to combat climate change, praised Gore, but other Republicans were either silent or critical of the Nobel panel.

Peter Wehner, a former White House official now with the Ethics and Public Policy Center, a conservative think tank, said the Nobel prize long has been devalued by conservatives, who see it as a way to send a message of disapproval to Bush. "If you either lost to Bush or are highly critical of Bush, I think your odds of winning the Nobel Peace Prize increase exponentially," he said.

The last American to win was former President Jimmy Carter, who received the prize in 2002, and who also has been sharply critical of Bush. Conservatives noted that the peace prize also has gone to such controversial figures as former Palestinian leader Yasser Arafat.

Nor did all scientists welcome Friday's news: MIT atmospheric physicist Richard Lindzen, who has criticized Gore's presentation and argued that global warming will not be catastrophic, said the award, along with the Oscar earned by "An Inconvenient Truth," demonstrates "that this issue has become more of a political and fashion issue than a scientific one."

The award came two days after a British judge ruled that, while Gore's documentary makes a strong case that human activity has contributed to global warming and that there is a sense of urgency to deal with it, the movie contained nine factual errors not supported by scientific consensus.

The Nobel award produced an immediate reaction from grass-roots groups seeking to draft Gore for a 2008 presidential campaign. Gore has repeatedly said the chances of his running are negligible but has not firmly closed the door. Aides moved to tamp down speculation that he might use the recognition to jump into the race. "He has no intentions of running for president in 2008," Kreider told reporters in Palo Alto.

Michael Feldman, a Gore adviser, said Friday in an e-mail message: "He has been very consistent in his public statements about his plans, and I don't think this affects his posture at all. He remains fully focused on trying to help solve the climate crisis."

Roy Neel, another longtime Gore adviser, said he had talked to the former vice president after the announcement. "I think he feels a little humbled by this," he said. As for the possible 2008 implications, he said the award might increase the importance of the issue of climate change in the campaign dialogue.