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PARIS: Earth’s climate appears to be changing more quickly and
deeply than a benchmark UN report for policymakers predicted, top
scientists said ahead of international climate talks starting Monday
in Poland.
Evidence published since the Intergovernmental
Panel for Climate Change’s (IPCC) February 2007 report suggests
that future global warming may be driven not just by things over
which humans have a degree of control, such as burning fossil fuels
or destroying forests, a half-dozen climate experts told Agence
France-Presse.
Even without additional drivers, the IPCC has
warned that current rates of greenhouse gas emissions, if unchecked,
would unleash devastating droughts, floods and huge increases in
human misery by century’s end.
But the new studies, they say, indicate that
human activity may be triggering powerful natural forces that would
be nearly impossible to reverse and that could push temperatures up
even further.
At the top of the list for virtually all of the
scientists canvassed was the rapid melting of the Arctic ice cap.
“In the last couple of years, Arctic Sea ice
is at an all-time low in summer, which has got a lot of people very,
very concerned,” commented Robert Watson, Chief Scientific Advisor
for Britain’s department for environmental affairs and chairman of
the IPCC’s previous assessment in 2001.
“This has implications for Earth’s climate
because it can clearly lead to a positive feedback effect,” he
said in an interview.
When the reflective ice surface retreats, the
Sun’s radiation—heat—is absorbed by open water rather than
bounced back into the atmosphere, creating a vicious circle of
heating.
“We had always known that the Arctic was going
to respond first,” said Mark Serreze of the National Snow and Ice
Data Center in Boulder, Colorado. “What has us puzzled is that the
changes are even faster than we would have thought possible,” he
said by phone.
New data on the rate at which oceans might rise
has also caused consternation.
“The most recent IPCC report was prior to . .
. the measurements of increasing mass loss from Greenland and
Antarctica, which are disintegrating much faster than IPCC
estimates,” said climatologist James Hansen, head of NASA’s
Goddard Institute for Space Studies in New York.
-- AFP
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