"WWF believe it is a historic moment here," said Stephan Singer, the conservation organisation's European head of climate and energy.

"It has been shown for the first time that stopping climate pollution in a very ambitious way does not cost a fortune ... There is no excuse for any government to argue that it is going to cause their economy to collapse."

The report by the Intergovernmental Panel on Climate Change -- top scientists and climate experts from 120 countries who come together under a UN banner -- said in their report Friday that the tools are available to battle climate change at minimal cost to the global economy.

Heading off the worst effects of climate change would shave less than 0.12 percent off the world's economic growth in the years 2030 and 2050, the report said.

That would cover the cost of efforts to limit global warming to 2.0-2.4 degrees Celsius (3.6-4.3 degrees Fahrenheit), generally recognised by experts as the threshold at which some of the most extreme impacts of climate change will begin.

Greenpeace said it too was happy with the report, and demanded a "serious political response" from world leaders.

"With this report we now have very, very clear options on how to deal with climate change," said Stephanie Tunmore, a Greenpeace climate and energy campaigner.

"It's up to the policymakers to now make a decision on what is a dangerous level of climate change and make sure we avoid it."

Singer said the Chinese delegation had been particularly vocal in voicing its concerns about the report, but added that in the end everyone accepted its findings.

"It came out much better than we thought... This is a victory of science over the fossil fuel industry (and) economic sceptics," Singer told AFP soon after the document was approved.

"Start tomorrow, don't wait for another summit," he urged governments.

The report was the product of five days of marathon negotiations to find proposals to battle climate change, and said emissions need to start declining by 2015 to avoid the worst effects of global warming.

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