New research from the first ever sea voyage across the Pole - made by icebreakers - to be published later this year, shows that a layer of water under the ice is warming up astonishingly fast.
Scientists suspect that the rapid rise in temperature is connected to a disruption of currents in the North Atlantic reported in the Independent on Sunday earlier this year. The disruption - which follows the failure of the "Odden Feature" in the Greenland Sea for the third year in succession - threatens to affect the Gulf stream.
Computer modelling of the likely progress of global warming at the Meteorological Office's Hadley Centre for Climate Research and Prediction forecasts that the Arctic will warm up faster than anywhere else on earth - by between 6C and 8C over the next century.
Dr Peter Wadhams, Co-ordinator of the European Commission's Sub-Polar Ocean Programme, says that this would be enough to melt the now-permanent ice. "We would see the sea ice cap going completely in the summer, but remaining in the winter," he said.
New research, to be published later this year by Professor Knut Aagaard of the University of Washington in Seattle, comes from a month-long 2,300- mile voyage through the polar ice from Alaska to Iceland in 1994 by two icebreakers, the Polar Sea from the US and Canada's Louis St-Laurent. When they reached the Pole in August they unexpectedly met a Russian icebreaker carrying 75 schoolchildren who had won a competition. The three ships completed the voyage together.
Measurements taken on the journey revealed "a large overall warming" of a layer of water some 200 metres below the ice cap. Its temperature appears to have jumped by 1C in just five years.
Other research shows that water flowing up the Norwegian coast into the Arctic - easily tracked because it is contaminated with radioactive pollution from Sellafield - has also grown warmer recently. Meanwhile the amount of ice drifting down from the Arctic to the Greenland Sea has fallen by nearly 40 per cent.
Dr Wadhams, who works at the Scott Polar Research Institute in Cambridge, attributes the increasing temperatures to global warming and says they are likely to speed up the melting of the ice. This, in itself, is unlikely to cause an increase in sea level rise, as floating ice displaces water and the ice caps on land masses like Greenland will take much longer to melt.
Dr Wadhams says that the changes in the Arctic are likely to be connected to the disappearance of the Odden Feature, where water is sucked down from the surface to the sea bed, feeding a vast deep current which links all of the world's oceans. He says: "These two extremely significant phenomena have suddenly occurred in the last five years. They may well be connected. This has made the Arctic the focus of attention in marine science."