"Whether it's something that we need to be totally alarmed about, or nature taking its course, I don't know," said the sceptical senator from Georgia.
The shocked reaction reflected growing concern about global warming at the meeting of corporate and political leaders in Davos that ended on Sunday.
Executives revealed that their greening was fuelled by a combination of personal conscience, fears about the economic impact, and business acumen helped on by a growing dose of regulation.
"The alternative energy world is no longer the domain of some Birkenstock wearing wind power types out on some Oregon farm," said Dan Esty, director of the Yale Center for Environmental Law and Policy.
"We now have some of the mightiest companies in the world.
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Chambliss's comments in one of a host of debates on the topic at the Swiss resort came just days before the UN's scientific authority on climate change issues its first update in six years.
The report by the Intergovernmental Panel on Cl