Global
Warming Devastates
Sea Ice In Arctic Circle
By Steve Connor
04 October 2006
The
Independent
Sea
ice in the Arctic last month melted to its second lowest monthly minimum
in the 29-year record of satellite measurements.
Scientists at the US National
Snow and Ice Data Centre (NSIDC) in Colorado said the total surface
area covered by sea ice during September was smaller than in any previous
year apart from 2005, when it reached an all-time record minimum. And
it was only a sudden change to cool and stormy weather in August that
prevented another record low being set this September, they said.
"At this rate, the Arctic
Ocean will have no ice in September by the year 2060," said Julienne
Strove, one of the NSIDC's research scientists.
The Arctic sea ice floats
on the ocean and its surface coverage varies naturally in line with
seasonal temperature changes, with an absolute minimum in summer occurring
around mid-September.
However, rising temperatures
have seen a steady long-term decline in sea ice during the summer months,
with little recovery during the Arctic winter.
Summer sea ice across the
entire Arctic has been dwindling steadily since satellite measurements
began in 1977. But since 2002 scientists have detected a noticeable
acceleration in the rate of summer loss, which they believe is caused
by global warming.
Mark Serreze, a senior research
scientist at the NSIDC, said this summer could easily have surpassed
last year's record loss if it had not been for the change in the weather.
"If fairly cool and
stormy conditions hadn't appeared in August, slowing the rate of summer
ice loss, I feel certain that 2006 would have surpassed last year's
record low for September sea ice," Dr Serreze said.
"August broke the Arctic
heatwave and slowed the melt, and storm conditions led to wind patterns
that tend to spread the existing ice over a larger area."
Arctic sea ice acts like
an insulating lid on the northernmost ocean, reflecting sunlight and
preventing the water from absorbing heat and warming up.
Scientists fear that as more
and more sea ice is lost, a "positive feedback" will kick
in, with the Arctic Ocean absorbing more sunlight, which will in turn
cause the loss of more sea ice.
"I'm not terribly optimistic
about the future of the ice," Dr Serreze said. "Although it
would come as no surprise to see some recovery of the sea ice in the
next few years - such fluctuations are part of natural variability -
the long-term trend seems increasingly clear. As greenhouse gases continue
to rise, the Arctic will continue to lose its ice. You can't argue with
the physics."
The Arctic has seen some
of the largest increases in average temperatures in the world over the
past few decades, and could be one of the places hardest hit by climate
change.
"Arctic sea ice is an
important climate indicator because it's so sensitive to this initial
warming trend," said Ted Scambos, a senior scientist at the Snow
and Ice Data Centre.
© 2006 Independent News and Media Limited
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