[Vision2020] GOING, GOING, GONE: April's Arctic Ice Cap Was Smallest in Recorded History.
thansen at moscow.com
Mon May 7 11:34:38 PDT 2007
>From today's (May 7, 2007) Anchorage Daily News -
Sea ice melting faster
GOING, GOING, GONE: April's Arctic ice cap was smallest in recorded history.
By GEORGE BRYSON
Anchorage Daily News
Published: May 7, 2007
Last Modified: May 7, 2007 at 02:09 AM
Imagine three-fourths of the land mass of Alaska disappearing in a decade.
That's roughly the amount of sea ice that has vanished from the Arctic ice
cap in recent years -- and now it's melting faster.
So say two new reports from ice experts last week that climate-change
scientists consider troubling, since sea ice keeps the Earth cool. An
ice-free ocean warms it up.
One report noted there was less Arctic sea ice in April than had ever been
recorded that month since satellite imagery of the northern ocean began in
1979. Another found that the melting of the Arctic ice cap is proceeding
faster than anyone expected.
That second finding -- announced jointly by scientists at the National Snow
and Ice Data Center and the National Center for Atmospheric Research --
concludes that all the summer Arctic sea ice should disappear "about 30
years" sooner than mainstream climate models earlier predicted.
The Intergovernmental Panel on Climate Change, widely regarded as the gold
standard for such projections, had estimated that summer sea ice in the
Arctic probably declined at a rate of 2.5 percent a decade from 1953 to
2006. At that rate, the IPCC said, the summer ice cap would disappear
sometime between 2050 and next century.
That estimate reflected the average of 18 separate IPCC climate scenarios,
the most pessimistic of which placed the rate of ice shrinkage at 5.4
percent a decade.
But newly available data, "blending early aircraft and ship reports with
more recent satellite measurements," show that the September ice actually
declined at a rate of about 7.8 percent per decade from 1953 to 2006, the
ice data center reported in a press statement.
"Because of this disparity, the shrinking of summertime ice is about 30
years ahead of the climate model projections," said NSIDC scientist and
co-author Ted Scambos.
That means the summer ice cap could disappear earlier than 2050. If it does,
scientists say, the Earth will begin warming much more rapidly -- as the
Arctic Ocean begins to soak up all of the sun's rays without the protective
shield of the ice cap to bounce them back into space.
In Alaska, polar bears would lose the summer ice floes they depend upon to
hunt for seals. Instead, they'd have to find food on the mainland. But that
might be the least of the Earth's ills. If a rapidly warming climate causes
major portions of Greenland or Antarctica to melt, the rising sea level
would drown low-lying seaports and communities all around the world.
Portions of Manhattan and the coast of Florida would disappear.
APRIL ICE AT RECORD LOW
Drastic sounding scenarios such as those grew only more credible last week
as scientists who measure the Arctic ice reported a new low for the month of
April. Satellite imagery that can peer through clouds found only 13.9
million square kilometers of ice.
By comparison, the long-term average April ice pack (measured from 1979 to
2000) is about 15 million square kilometers. The difference between that and
this April -- 1.1 million square kilometers -- represents the loss of an
area of ice more than 1 1/2 times the size of Texas. Or three-fourths the
area of Alaska.
Seeya round town, Moscow.
"If not us, who?
If not now, when?"
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