Meanwhile, the United Nations says it will investigate a series of emails which allegedly show some of the world's leading researchers discussing ways to suppress opponents' views.
At stake are claims being made in ever-widening circles that the emails cast doubt on scientific data that shows human activity causes climate change.
One of the controversial emails refers to a "trick" being used to manipulate statistics and "hide the decline" while another vows to withhold certain result "somehow", even if we have to "redefine" the peer review literature.
As the scientific impact ignites fresh debate, potentially more damaging are the political implications.
Al Jazeera's Jonah Hull reports.
climate change barack obama copenhagen united nations denmark al jazeera aljazeera jonah hull