THE impact of global warming has been exaggerated by some scientists according to the British government's chief scientific adviser.

John Beddington said there is an urgent need for more honest disclosure of the uncertainty of predictions about the rate of climate change, The Australian reported.

Professor Beddington said climate scientists should be less hostile to sceptics who questioned man-made global warming. He condemned scientists who refused to publish the data underpinning their reports.

Australia's chief scientist, Penny Sackett, told The Australian last night she shared Professor Beddington's concerns.

Professor Sackett said climate change was a scientific reality but there was a need for absolute openness and rigour in the presentation of evidence, including recognition of which aspects of climate change science were imprecise and required further research.

Professor Beddington said public confidence in climate science would be improved if there were more openness about its uncertainties, even if that meant admitting that sceptics had been right on some hotly disputed issues.

He said: "I don't think it's healthy to dismiss proper scepticism. Science grows and improves in the light of criticism. There is a fundamental uncertainty about climate change prediction that can't be changed."

He said the false claim in the Intergovernmental Panel on Climate Change's 2007 report that the glaciers would disappear by 2035 had exposed a wider problem with the way some evidence was presented.

"Certain unqualified statements have been unfortunate. We have a problem in communicating uncertainty. There's definitely an issue there. If there wasn't, there wouldn't be the level of scepticism.

"All of these predictions have to be caveated by saying, `There's a level of uncertainty about that'."

Professor Beddington said particular caution was needed when communicating predictions about climate change made with the help of computer models.

"It's unchallengeable that CO2 traps heat and warms the Earth and that burning fossil fuels shoves billions of tonnes of CO2 into the atmosphere. But where you can get challenges is on the speed of change.

For the full story, see The Australian.