Ice cap meltdown to cause 22ft floods
Telegraph (UK)
August 16, 2007

The Greenland ice sheet is doomed to melt away within the next three centuries and flood hundreds of millions of people out of their homes.

This is the stark warning given by a scientist who claims that current forecasts grossly overestimate how long the ice sheet will survive.

The Intergovernmental Panel on Climate Change (IPCC) has previously stated that a total meltdown is likely to take at least 1,000 years.

However, Dr Tim Lenton of the University of East Anglia, believes the risk are far greater than the IPCC suggests.

Speaking at a meeting in Cambridge organised by the British Antarctic Survey, Dr Lenton said: "We are close to being committed to a collapse of the Greenland ice sheet. But we don't think we have passed the tipping point yet."

A remnant of the last Ice Age, Greenland's ice cap is nearly two miles high.

But if the climate change crisis reached the point of no return and it were to melt then global sea levels would rise by 22ft and swallow up most of the world's coastal regions.

Dr Lenton's group - whose members include John Schellnhuber, the chief scientist on climate change at the recent G8 meeting in Germany - also identified eight environmental "tipping points" that could occur this century.

These include a collapse of the thermohaline circulation, which is the name given to a global system of ocean currents. Besides shutting down the Gulf Stream, this could also "switch off" the Asian monsoon and warm the Southern Ocean, perhaps destabilising the West Antarctica ice sheet.

Likewise, global warming may cause a near-permanent El Nino in the Pacific, which would also hasten runaway fires in the Amazon rainforest and its disappearance by the middle of the century.

Also at the Cambridge meeting Professor Lenny Smith, a statistician at the London School of Economics, warned about the "naive realism" of current climate models.

He singled out for criticism the government's UK Climate Impacts Programme as well as the Met Office.

He accused both of making detailed climate projections for individual regions when global climate models disagree strongly about how climate change will affect the British Isles.

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