Two leading climate scientists have broken ranks with their peers to declare that hopes of getting a meaningful deal on halting global warming this year are already lost.

Professor Kevin Anderson, director of the Tyndall Centre for Climate Change Research, and Professor Trevor Davies, one of the centre's founders, told The Times that it was time to start looking for alternatives to an international deal.

They made their comments on the eve of a three-day conference in Copenhagen this week in which thousands of climate change researchers will meet to discuss the latest discoveries in the field. The findings will be used in December when world leaders attend a UN summit, also in Copenhagen, to try to work out an international treaty on greenhouse gas emissions.

Professor Anderson and Professor Davies expect politicians at the summit merely to pay lip service to scientific evidence that greenhouse gas emissions need to be brought under control within a decade, if not sooner. They said that rather than wait for an international accord it was time now to consider what action could be taken.

“We all hope that Copenhagen will succeed but I think it will fail. We won't come up with a global agreement,” Professor Anderson said. “I think we will negotiate, there will be a few fudges and there will be a very weak daughter of Kyoto. I doubt it will be significantly based on the science of climate change.”

He is certain that negotiators will place a heavy reliance on technological solutions that have yet to be invented or proven, rather than recognise the scale and urgency of the problem. Professor Anderson believes that the severity of the likely impacts of climate change has been underplayed, and that to doubt that temperature rises could be limited to 2C is a political heresy.

He said that scientists had been held back from voicing their doubts. “The consequences of the numbers we come up with are politically unacceptable. It's difficult for people to stand up. To rock the boat significantly is difficult for them.”

Professor Davies, Pro-Vice Chancellor of the University of East Anglia (UEA), where the Tyndall Centre is based, shares this assessment and regards geoengineering schemes as a potential insurance policy.

The GeoEngineering Assessment and Research initiative (Gear) has now been set up at UEA to assess the projects that have been suggested. Among the geoengineering solutions that have been proposed are putting mirrors into orbit to reflect sunlight away from Earth, and encouraging the growth of plankton by pouring nutrients into the oceans.

“An increasing number of scientists are talking about Plan B now, the big, global geoengineering things,” Professor Davies said. “That's one of the reasons we've set up this centre - not that we think many of the aspects are sensible but because we think it's necessary to assess them.”

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