The meltdown in the Arctic is speeding up and as a result the North Pole could be ice-free by 2013 instead of in 60 years' time as earlier predicted, scientists have warned.

Their apprehensions are based on computer studies of satellite images that reveal that ice at North Pole melted at an unprecedented rate last week the disappearance is said to have exceeded the record loss of more than a million square kilometres in 2007 as global warming tightened its grip.

"It does not really matter whether 2007 and 2008 is the worst year on record for Arctic sea ice. The crucial point is that ice is clearly not building up enough over winter to restore cover and that when you combine current estimates of ice thickness with the extent of the ice cap, you get a very clear indication that the Arctic is going to be ice-free in summer in five years,” British newspaper The Observer quoted Prof Wieslaw Maslowski of the Naval Postgraduate School in Monterey as saying.

Using the United States' Navy supercomputers, his team produced a forecast which indicated that by 2013 there will be no ice in the Arctic other than a few outcrops on islands near Greenland and Canada between mid-July and mid-September.