Arctic sea-ice disappearing fast

May 27, 2010 at 12:46 am Leave a comment

The melting of the Arctic ice cap is one of the most foreboding signs of dangerous climate change. If too much ice melts, it will set off natural feedback loops that warm the planet even faster and disrupt weather patterns.

Yet a month ago, satellite data from the US National Snow and Ice Data Center (NSIDC) suggested the Arctic sea ice was growing back. In early April, the ice cover was close to the 30-year average.

But in past weeks, the NSIDC has recorded a rapid drop in ice cover. By late May, the ice cover had dropped below what it was in May 2007 — the lowest year on record.

By September 2007, the ice cap had retreated to 40% below the average. The news sent shockwaves through the scientific community. This year, the melt rate is on track to break this record.

The NSIDC’s Mark Serreze told news agency Canadian Press on May 19: “Could we break another record this year? I think it’s quite possible. We are going to lose the summer sea-ice cover. We can’t go back.”

Scientists say the ice is melting back so quickly is because it’s now much thinner than before.

Sea-ice expert David Barber, of the University of Manitoba, told Canadian Press that only about 18% of the ice cap consists of thick, multi-year ice today. In the early 80s, the figure was about 90%.

The new, thin ice is breaking up faster as temperatures rise. April was the hottest month recorded since records began in the 1880s. Furthermore, warming in the Arctic region has been about 2 to 3 times above the global average.

Bizarre weather patterns have also been recorded recently in the Arctic. A 3-minute rainstorm surprised a scientific group on Ellef Ringnes Island, near the North Pole, in late April.

The team’s expedition director, Pen Hadow, told Reuters: “It’s definitely a shocker … the general feeling within the polar community is that rainfall in the high Canadian Arctic in April is a freak event.”

Environment Canada’s senior climatologist, David Phillips, reacted similarly. He told CBC News on April 29: “My business is weird, wild and wacky weather, and this is up there among fish falling from the sky or Niagara Falls running dry. I mean, it really is strange. You just don’t expect it to rain in the High Arctic in April.”

Hadow’s team also reported abnormally thin ice and strong winds for that time of year.

In February, NASA glaciologist Jay Zwally told EarthSky.com that studies had confirmed the Greenland ice sheet was also losing ice fast — at rate of about 150 gigatons a year.

He said: “ One way to think about how much 150 gigatons is, [is] that if you had earth movers that carried 150 tons each, it would take 2,000 of them each minute to dump the excess ice into the ocean.”

Zwally said “the important thing to know about the Earth’s ice sheets is that they are changing, that they are responding to climate change.

“The idea of the canary in the coal mine is that it’s a warning sign to get out of the coal mines when the gases build up. The things that are taking place on the Earth — the melting of the ice sheet in Greenland, the increase and the loss of sea ice in the Arctic ocean — these are warning signs of the same type.”

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Entry filed under: Arctic.

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