Evidence that global warming is man-made is getting stronger, the head of a UN panel of climate scientists said, in a further blow to sceptics who argue rising temperatures can be explained by natural variations.
Rajendra Pachauri spoke on the sidelines of a conference in Qatar where 200 nations are trying to reach a deal to cut emissions of greenhouse gases to avert floods, droughts, heatwaves and mounting sea levels.
The influential UN climate panel said the probability human activity was the main cause of climate change was "at least 90 per cent" in its last report in 2007.
Pachauri told Reuters late on Wednesday he expected the panel would raise the level of that likelihood even higher in its next report, due in 2013.
It is an annual ritual: nearly 200 nations sit down at the end of each year for two weeks of glacially paced negotiations meant to stop global warming. Meanwhile, leading scientific and economic bodies warn the best evidence suggests time is fast running out to cut greenhouse gas emissions.
Starting Monday it is the turn of the oil-dominated Qatar to host the latest major United Nations’ climate summit.