ABC News Online, Posted Thu Feb 26, 2009 1:38pm AEDT
Icecaps around the North and South poles are melting faster and in a more widespread manner than expected, raising sea levels and fuelling climate change, a major scientific survey has showed.
The International Polar Year survey found that warming in the Antarctic is "much more widespread than was thought", while Arctic sea ice is diminishing and the melting of Greenland's ice cover is accelerating.
The frozen and often inaccessible polar regions have long been regarded as some of the most sensitive barometers of environmental change and global warming because of their influence on the world's oceans and atmosphere.
Preliminary findings from the two-year survey by 10,000 scientists revealed new evidence that the ocean around the Antarctic has warmed more rapidly than the global average, the World Meteorological Organisation and the International Council for Science said in a statement.
Meanwhile, shifts in temperature patterns deep underwater indicated that the continent's land ice sheet is melting faster than reckoned.
"These changes are signs that global warming is affecting the Antarctic in ways not previously suspected," the statement added.
"These assessments continue to be refined, but it now appears that both the Greenland and the Antarctic ice sheets are losing mass and thus raising sea level, and that the rate of ice loss from Greenland is growing."
Shrinking sea ice was expected around Antarctica, while Arctic sea ice decreased to its lowest level since satellite records began.
During the survey in 2007 and 2008, special expeditions in the Arctic also found an "unprecedented rate" of floating drift ice, providing "compelling evidence of changes" in the region.
But the focus was on the erosion of land-based ice sheets of Greenland and the Antarctic, which hold the bulk of the world's freshwater reserves and can generate sea level changes of global scale as they melt.