London, April 26 : Scientists have warned that the North Pole might be free of ice before the end of this year, turning into a vast expanse of water.
According to a report in New Scientist, Arctic scientists are preparing for this grim possibility after seeing a number of factors that have this year led to most of the Arctic ice being thin and vulnerable as it enters its summer melting season.
In September 2007, Arctic sea ice reached a record low, opening up the fabled North-West passage that runs from Greenland to Alaska.
The ice expanded again over the winter and in March 2008 covered a greater area than it had in March 2007. Although this was billed as good news in many media sources, the trend since 1978 is on the decline.
Although Arctic ice is at its maximum in March, that maximum is declining by 44,000 km square per year on average.
The extent of the ice is only half the picture, with satellite images showing that most of the Arctic ice at the moment is thin, young ice that has only been around since last autumn.
A fact that is adding to the worries is that multi-year ice - the stuff that doesn't melt in the summer - is not piling up as fast as Arctic ice generally is melting.
On average each year about half of the first year ice, formed between September and March, melts during the following summer. In 2007, nearly all of it disappeared.
Moreover, an atmospheric phenomenon known as the Arctic oscillation kicked into its strong, "positive", phase this winter. This is known to generate winds which push multi-year ice out of the Arctic along the east coast of Greenland.
Together, these are the factors that have led to most of the Arctic ice now being so young and thin.
Thin ice is far more vulnerable than thick ice that has piled up over several years.
"There is this thin first-year ice even at the North Pole at the moment," said Mark Serreze, of the US National Snow and Ice Data Center (NSIDC). "This raises the spectre - the possibility that you could become ice free at the North Pole this year," he added.
"Even if you lost only half of the first-year ice this year - which would be average - you are still in for a very low ice extent this summer," said Serreze.