- Marian Wilkinson
- The Age, September 20, 2008
THE melting of Arctic sea ice has reached a critical stage, with satellite images showing the disappearance of ice this year peaking at a level close to last year's record.
The figures put the size of the Arctic sea ice at the end of the northern summer about one-third lower than the average recorded over the past three decades.
"This year further reinforces the strong negative trend in summertime ice extent observed over the past 30 years," analysts at the US National Snow and Ice Data Centre said in their latest report.
Hopes the Arctic can recover are now slim. As the sea ice fails to return, there are concerns the melt will become one of the "tipping points" pushing the planet towards faster climate change.
Scientists fear the vast Arctic sea ice, which covers the North Pole, could disappear during summer months within a few decades.
"We might see an ice-free Arctic Ocean by the year 2030, within some of our life times," the centre's Mark Serreze said. "There are some scientists out there who think that even that might be optimistic."
The loss of the Arctic sea ice in summer would be unprecedented in human history, says Dr Don Perovich, of the US Army's Cold Regions Research and Engineering Laboratory. "As near as we can tell, looking at the historical record, there's been ice in the Arctic in the summer for at least 16 million years."
The record melt is believed to be caused by a combination of naturally varying weather patterns combined with rising temperatures from global warming, caused in part by the burning of fossil fuels like oil, gas and coal.
With the end of the Arctic summer and the peaking of the melt, scientific attention will switch to the planet's other pole, the Antarctic, where Australian researchers plan a series of expeditions heavily focused on climate change.
Head of the Australian Antarctic Division, Dr Tony Press, said eight Australian scientists would explore the continent's interior as part of the global search to find the oldest ice core in the world.
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