October 20, 2005
Greenland icecap thickens slightly despite warming
OSLO (Reuters) - Greenland's ice-cap has thickened slightly
in recent years despite wide predictions of a thaw triggered by
global warming, a team of scientists said on Thursday.
The 3,000-meter (9,842-feet) thick ice-cap is a key concern
in debates about climate change because a total melt would
raise world sea levels by about 7 meters. And a runaway thaw
might slow the Gulf Stream that keeps the North Atlantic region
But satellite measurements showed that more snowfall was
falling and thickening the ice-cap, especially at high
altitudes, according to the report in the journal Science.
Glaciers at sea level have been retreating fast because of
a warming climate, making many other scientists believe the
entire ice-cap was thinning.
"The overall ice thickness changes are ... approximately
plus 5 cms (1.9 inches) a year or 54 cms (21.26 inches) over 11
years," according to the experts at Norwegian, Russian and U.S.
institutes led by Ola Johannessen at the Mohn Sverdrup center
for Global Ocean Studies and Operational Oceanography in
However, they said that the thickening seemed consistent
with theories of global warming, blamed by most experts on a
build-up of heat-trapping gases from (32.00F).
And the scientists said that the thickening of the ice-cap
might be offset by a melting of glaciers around the fringes of
Greenland. Satellite data was not good enough to measure the
melt nearer sea level.
Most models of global warming indicate that the Greenland
ice might melt within thousands of years if warming continues.
Oceans would rise by about 70 meters if the far bigger
ice-cap on Antarctica melted along with Greenland. Antarctica's
vast size acts as a deep freeze likely to slow any melt of the
The panel that advises the United Nations has predicted
that global sea levels might rise by almost a meter by 2100
because of a warming climate.
Such a rise would swamp low-lying Pacific islands and
warming could trigger more hurricanes, droughts, spread deserts
and drive thousands of species to extinction.
Still, a separate study in Science on Thursday said sea
levels were probably rising slightly because of a melt of ice
"Ice sheets now appear to be contributing modestly to sea
level rise because warming has increased mass loss from coastal
areas more than warming has increased mass gain from enhanced
snowfall in cold central regions," it said.
"Greenland presently makes the largest contribution to sea
level rise," according to the report by scientists led by
Richard Alley of Pennsylvania State University in the United