The House passed a bill this year that would set the United States' first federal mandatory limits on greenhouse gases. Factories, power plants and other sources would be required to cut emissions by 17 percent from 2005 levels by 2020 and by 83 percent by mid-century.

The EU is urging other rich countries to match its pledge to cut emissions by 20 percent from 1990 levels by 2020, and has said it would cut up to 30 percent if other rich countries follow suit.

European Commission President Jose Manuel Barroso said Monday the Copenhagen meeting could end in deadlock unless all participants agree to sweeping cuts in greenhouse gases.

"The public in Europe would not accept (such cuts) in the EU if the rest of the world does not move too," he told the Council on Foreign Relations in New York.

Barroso warned that inaction on climate change would cut the world's gross economic output by five percent a year.

"We must see that the costs of inaction are higher from an economic point of view than the costs of action," he told the Council on Foreign Relations in New York.

A new climate report released Monday by a climate initiative led by former British Prime Minister Tony Blair says 10 million jobs could be created by 2020, if developing nations agree to big cuts in greenhouse gases.

The initiative by Blair and The Climate Group, a London-based nonprofit advocacy organization, said it hoped the new research would help break the "deadlock" in global climate talks.

The report is based on computer modeling by Cambridge University economists. It also shows a global climate agreement could increase the world's GDP by 0.8 percent by 2020, as compared with the projected gross domestic product with no climate action.

"In economic terms, certainly in the medium and long-term, it's hugely to our economic benefit to get a global agreement," he told reporters at a New York hotel Sunday.

Blair acknowledged the pain of short-term investment, particularly during a global financial crisis, but called the upcoming Copenhagen negotiations "the moment when we move from a campaign to a policy program."

Blair also said climate change was one key area where his ideas diverged from those of Bush, whose administration claimed for years the Kyoto accord would have cost the U.S. economy 5 million jobs if Bush had not rejected it.

"I can't say I ever investigated that particular claim in detail," said Blair, who was Bush's closest ally on the Iraq war — a stance that ultimately contributed to Blair's decline in popularity at home and his stepping down as both Labor Party leader and prime minister.

"But all I can tell you from our perspective in the U.K. — and if you look at the rest of Europe — we have not been losing jobs as a result of taking action on climate change. If anything, we've been gaining jobs."