Melting Antartic sounds alarm for globe: Temperatures in the Antartic have risen by 2.5 degrees centigrade in 40 years, writes Nicholas Schoon

A RAPID temperature rise in the Antarctic peninsula, the fastest sustained warming since worldwide temperature records began 130 years ago, may be an advance warning that pollution is swiftly altering the global climate.

Temperatures at the British Antarctic Surveys Faraday research base have risen 2.5C in the past four decades. There is evidence of a similar rapid warming in Greenland 150,000 years ago, at the end of an ice age.

The British Antarctic Survey (BAS) detected another global environmental threat nearly 10 years ago, finding the first holes in the high-level ozone layer from its Halley station.

The warming at the Faraday station, 1,500 miles from the South Pole, amounts to about 0.5C per decade in annual average temperatures. Records began there in 1945.

Worldwide warming trends may be exaggerated by local condi tions on the Antarctic peninsula, survey scientists believe. It could be a sentinel region, said Dr John King, head of the surveys meteorological group. Weve already seen the Antarctic playing this role in demonstrating how man-made chemicals were degrading the ozone layer.

Analysis of worldwide temperature records show average annual global temperatures have risen by about 0.6C over 130 years. The rate of warming found in the Faraday record, the longest on the Antarctic, are about 10 times faster.

BAS scientists believe small increases in temperature around the Antarctic peninsula may be amplified by the break up of the local pack ice and changes in atmospheric circulation.

The BAS recently reported the disintegration of the Wardie ice shelf next to the peninsula, with the loss of 500 square miles of pack ice between 1969 and 1989. Islets near the base have also lost much of their permanent ice cover. The warming appears to be confined to the western Antarctic. Dr King said: The Faraday base is near the edge of the ice shelves and small changes in sea ice cause big changes in temperature. But the record of annual average temperatures was a fluctuating one that could represent natural climatic variation rather than man-made influence. Theory and advanced computer predictions of man-made global warming predict the poles will experience greater warming than the tropics and mid-latitudes.

There are fears that a build up of warmth in the atmosphere caused by carbon dioxide and other pollutants could eventually detach and melt ice sheets that cover the land mass of Antarctica and Greenland. If that happened, sea levels would rise by more than 200ft worldwide, submerging vast areas of inhabited land. But if this is a threat, I think were discussing centuries rather than decades, said Dr Chris Doake, a glaciologist with the Cambridge-based BAS.

The West Antarctic ice sheet, which caps about one-third of the continent, is thought to be less stable than the East Antarctic one because much of the land on which it rests is below sea level.

The problem for politicians and society in dealing with the build-up of heat-trapping pollutants in the atmosphere is that by the time scientists have absolute proof that it is happening it will be too late to stop it.

If emissions of all the greenhouse gas pollutants produced by burning fossil fuels, industrial processes, land clearance and farming were stopped overnight, any global warming effects would still carry on for tens of years.

But there is no prospect of any rapid curbs in these emissions; most of them are likely to continue rising rapidly for decades as developing nations industrialise while rich countries continue to burn huge quantities of coal, oil and gas.

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