saving the world from global warming.
It was only an academic symposium, and none of the scholars - including a Canadian Inuit woman in the running for a "green Nobel" - claimed to have a master plan to eradicate the threat of climate change. Still, there was a whiff of validation, if not victory, in the air.
"The scientific findings are clear: climate is changing, and it is a response to human activities," said Mario Molina, a chemist who won the Nobel Prize in 1995 for being the first to posit that chlorofluorocarbons and similar chemicals could poke a hole in the ozone layer.
Molina was speaking during a week of Nobel announcements that the laureates at this meeting hoped would culminate today with the award of a "green" Peace Prize.
Among those rumoured as candidates are three climate-change evangelists: former U.S. vice president Al Gore; Sheila Watt-Cloutier, a Canadian who has warned about the threat to Arctic wildlife; and Rajendra Pachauri, an Indian scientist who is chair of the Intergovernmental Panel on Climate Change, which assesses the risks of greenhouse gases for the United Nations.
Pachauri kicked things off with his panel's latest findings, which he said ought to settle the debate about whether humans are making the planet dangerously warmer.
"People do raise this issue of what's happening with the science, and whether the science is on board," said Pachauri.
"I think that argument really should be over.''
Even if the Nobel committee passes over all the candidates who have worked on issues related to climate change, there was a bracing sense here that public opinion had finally caught up to science on the topic.
No longer is the United States, which refused to sign the Kyoto Protocol and continues to go its own way in climate policy, viewed as an immovable barrier to a global replacement deal.
"If you look what's happened in the last year or so, it's been quite extraordinary," said Nicholas Stern, a British economist who wrote last year on the potential costs of not confronting climate change.
"It wasn't until January this year that President (George W.) Bush was at all clear there was a problem; now he's sounding as if he's a leader in the response to this problem," Stern said, stifling a chuckle.
This year's Nobel Peace Prize is being conferred for two starkly different ways of communicating about human-caused global warming.
The Intergovernmental Panel on Climate Change speaks in the measured voice of peer-reviewed science and government-negotiations. In four reports issued since 1990, it has always focused on the most noncontroversial findings. In 2001, for instance, it concluded, "There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities."
The other awardee, former Vice President Al Gore, delivers brimstone-laden warnings of an unfolding "planetary emergency." He has not shied from emphasizing the most emotionally potent, though least certain, consequences of warming, such as its link to hurricane intensity and the likely pace of sea-level rise.
Gary Yohe, an economist at Wesleyan University and a lead author of some of the climate panel's reports in 2001 and this year, said he was thrilled to have climate elevated by the prize. But he said the focus on Mr. Gore as a personality and politician might distract from the strong consensus among researchers on the risks posed by unfettered greenhouse gas emissions.
"If the spectacular nature of his presentations and the personalities involved become the story instead of the science," he said, "then it becomes counterproductive."
But some scientists, historians and policy experts said yesterday that both messages - with all the imperfections attending each - seem necessary for a looming, planet-scale problem to get attention.
The Nobel "is honoring the science and the publicity, and they're necessarily different," said Spencer A. Weart, a science historian at the American Institute of Physics and author of The Discovery of Global Warming, a recent book charting climate research through the last century.
He added that both are essential because the science alone, laden with complexity and some unavoidable uncertainty, would never jog average citizens or most elected officials.
"The I.P.C.C. was set up to be the lowest common denominator, to weed out anything anyone could disagree with," Dr. Weart said. "It was deliberately created, largely under the influence of Reagan administration, because governments didn't want a bunch of self-appointed scientists from academies and so on out there. It's no accident that it's the Intergovernmental panel," he said. "Even the Saudi government has to agree. That means that when the I.P.C.C. says you're in trouble, you're really in trouble."
But if the profile of the climate issue had not been raised with the release of "An Inconvenient Truth," the documentary on Mr. Gore's climate work, the panel's latest reports, released in three parts from February through April, would not have had nearly as much impact, some experts said.
Among those crediting Mr. Gore for elevating the climate issue - if differing from him dramatically on solutions - is the former House speaker Newt Gingrich. Mr. Gingrich is co-author of a new book, "A Contract With the Earth," accepting that human-caused warming poses unacceptable risks and pushing, among other things, for the United States to aggressively develop non-polluting energy technologies.
"In a way, Vice President Gore, by raising the intensity of the issue, by talking about it, raised the challenge for those of us who think there's an alternative to say, O.K., right emotions, wrong answer," Mr. Gingrich said in an interview this week before the Nobel announcement. "But then we have an obligation to provide an answer." He said he prefers incentives to boost energy research over Mr. Gore's preference for a mandatory limit on gases, both nationally and globally.
Some longtime critics were less willing to give Mr. Gore credit. "I am delighted that Al Gore got a Peace Prize - which is NOT to be confused with a Nobel Prize for science," S. Fred Singer, an atmospheric scientist and one of a small, vocal group of longtime skeptics of dangerous human-caused warming, said in an email.
Some scientists who have participated in the panel's reviews and published climate studies for many years said the award reflected that the global community had, after two decades of cyclical attention - and rising emissions - absorbed that humans are pushing on the planet's thermostat.
But several such experts said they remained concerned by a deep persistent split over what to do about it - between those, like Mr. Gingrich and President Bush, who prefer a focus on technological advances and those, like Mr. Gore, seeking a regulatory approach forcing cuts in emissions.
"It's been a long slog," said Michael Oppenheimer, an atmospheric scientist who has participated in the periodic climate assessments since the early days of the panel. "The award reminds us that expert advice can influence people and policy, that sometimes governments do listen to reason, and that the idea that reason can guide human action is very much alive, if not yet fully realized."
He added that it was now up to governments to act.
"Public attention is now engaged at the highest level it will probably ever be engaged," Dr. Oppenheimer said. "Now it's incumbent on governments to grab the opportunity and work with each other and at the national level to finally craft a solution."