The Nobel-winning panel of world climate experts on Monday launched a debate over a landmark report after a top UN official warned any failure to curb global warming would be "criminally irresponsible."

"The effects of climate change are being felt already," Yvo de Boer, executive secretary of the UN Framework Convention on Climate Change (UNFCCC), said. "Climate change will hit hardest the poorest and most vulnerable countries. Its overall effect, however, will be felt by everyone and will in some cases threaten people's very survival." "Failing to recognize the urgency of this message and acting on it would be nothing less than criminally irresponsible," he said. De Boer was speaking at the start of a meeting of the Intergovernmental Panel on Climate Change (IPCC).

The UN forum of scientists, economists and other experts won this year's Nobel Peace Prize alongside climate campaigner and former US president Al Gore. The document to be issued on Saturday distills a 2,500-page, three-volume assessment issued earlier this year -- the first such review since 2001 -- into a 25-page synthesis for policymakers.

Debate in Monday's opening session revolved around the length of the synthesis document, and whether to present it as a "stand-alone" report or to link it explicitly to more detailed findings in the three previous reports, sources said. The decision is important, for the synthesis report encapsulates core facts that policymakers are likely to take into account for years to come. It could thus shape many decisions on how to tackle carbon emissions and adapt to climate change.

"This will be the report that everyone will turn to time and time again over the next five years to see what the science is telling us," said Hans Verolme, head of WWF's Global Climate Change Programme.


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