Arctic Ice

There is a news story out suggesting that the rate of the Arctic ice melting is faster than anticipated. "Ice at North Pole could be gone by 2040, scientists warn - Dire news on global warming as Geophysical Union meets in S.F."

(Apparently some people had been holding out for 2080 or 2100).

I did a search and noticed that an article I put up in August - from Edmonton - suggested there may only be a couple of decades - which put the date at more like 2036 or so then. Maybe these scientists are just catching up. It was quite a warm summer and fall - so maybe the earlier prediction no longer seems so far fetched.

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From the new article:

Sea ice that for centuries has covered much of the High Arctic has been shrinking at a record pace due to global warming, and as winter began last month in the oceans surrounding the North Pole, larger stretches of open water remained free of ice than ever before, climate scientists reported Monday.

The extent of Arctic sea ice is a key signal of the world's warming rate, and its effects are widespread: Immensely valuable fisheries shift from the coasts of one continent to another, algae and plankton disappear in some areas and increase in others, Arctic wildlife becomes endangered, and torrents of fresh water from melting ice alter the salinity of seas far to the south.

Where only a few months ago experts were predicting that if the present rate of warming continues unchecked there could be no sea ice left in the Arctic by the end of this century, the latest climate calculations indicate the seas there could well be totally ice-free by 2040, the specialists warned.

The latest assessment of global warming and its effects came at the opening of the American Geophysical Union's annual meeting in San Francisco, where more than 15,000 scientists are gathering at Moscone Center this week to present new data from their research in topics as varied as earthquakes, weather, oceanography and space research....

With Arctic air temperatures increasing more rapidly than ever before, sea ice diminishing, permafrost thawing, and trees and shrubs increasing across the tundra, a "tipping point" when the changes become irreversible may well be at hand, said Larry Hinzman of the University of Alaska.

The "tipping point" is manifest in the rapid decrease of the Arctic's sea ice cover, according to Mark Serreze of the Snow and Ice Data Center. Satellites in 2005 measured the smallest extent of sea ice ever recorded, he said, and after the summer melt period, the ice returned at the slowest rate ever.

This year is even more alarming, Serreze said. Although the extent of sea ice was not as limited as it was in 2005, he said, by the end of last November, satellite measurements showed that the ice had failed to extend as widely as the previous year and was more than 772 square miles shy of its average extent, he said.

In 20 years, Serreze said, the extent of Arctic sea ice will be reduced by 80 percent. "And that could be another tipping point. It is no longer recovering as it should, and if it reaches a critical level, it may never recover at all."