http://www.commondreams.org/headlines02/0719-02.htm
Published on Friday,
July 19, 2002 by OneWorld.net
Global Warming
New Studies Raise Alarm About Global Ice
Melt
by Jim Lobe
In one more piece of
evidence that the Earth's climate is
warming rapidly, a new study published Friday in Science
magazine has found that Alaska's glaciers are melting more
quickly than previously believed.
The resulting meltwater
is also contributing much more to the
rise in sea level than previous estimates, according to the
study by a team of University of Alaska researchers in Fairbanks,
which also found that both trends are accelerating.
"The rate of thinning
has doubled in the past five years,
compared to the 40 years before," said Anthony Arendt,
the study's main author.
As a result, the Alaskan
contribution to sea-level rise has
also doubled, to about 0.27 mms a year during the past decade,
or about twice the amount assumed by an international panel
of scientists that last year predicted sea level would rise
up to 11 centimeters (about four inches) by the end of this
century due to global warming.
"It's a big deal
if those rates have been underestimated,"
said Tom Janetos, an expert at the Heinz Center for Science,
Economics and the Environment. "If these results are correct,
the rate of sea-level rise has probably been underestimated
in all international assessments."
More than 100 million
people live on land within one meter
of sea level, and storm surges can devastate coral reefs
and low-lying islands and coastlines around the world.
"Although some
degree of sea-level rise is anticipated in
the coming decades, the greater the rise and the faster it
occurs, the greater the impact will be on human population,"
according to Benjamin Preston, a researcher at the
Washington D.C.-based Pew Center on Global Climate Change.
Despite their relatively
small land mass--about 13 percent
of the world's total mountain glacier area--Alaska's glaciers
contribute about half of all sea rise caused by glacial melt
and about twice as much as the amount of water lost from
the entire Greenland Ice Sheet, according to the study.
A second study published
in Science Friday will also add
to concerns about the impact on oceans of faster ice melt.
Using records compiled over the last 40 years, researchers
at Columbia University found a sharp decline in the salinity
of waters in the Ross Sea near Antarctica, as well as warmer
air and water temperatures in the area.
The warmer atmosphere
appears to have caused more rain and
snowfall, less sea ice, and faster melting of the West
Antarctic ice sheet, according to the study. Previously,
low salinity found in masses of seawater flowing from the
Antarctic to the South Pacific was attributed to more
precipitation, but the new study confirms that increased
melting of the ice cap itself is also a major factor.
Declining salinity
could affect major ocean currents,
such as the Gulf Stream which warms the waters and climate
of the North Atlantic region, according to oceanographers.
One increasingly prominent theory suggests that a
significant flow of fresh water into the North Atlantic
could actually reverse the Gulf Stream, as it has in the
past, causing an abrupt plunge in water and air temperatures
in northeastern North America and northwestern Europe.
"If scientists
have underestimated the amount of fresh
water likely to enter the oceans in coming decades,
they may have also underestimated the risk of such a
phenomenon occurring," said Preston.
Copyright 2002 OneWorld.net
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