WASHINGTON Arctic sea ice melted to its lowest
level ever this week, shattering a record set in 2005 and
continuing a trend spurred by human-caused global warming,
scientists said on Thursday.
"It's the biggest drop from a previous record that we've
ever had and it's really quite astounding," said Walt Meier, a
research scientist at the U.S. National Snow and Ice Data
Center in Colorado.
Sea ice freezes and melts seasonally, but never has it
ebbed to this small a patch, the data center said in a
statement. Compared to 2005, the previous record-low year for
Arctic sea ice, this year saw a decrease of more than 386,100
That is about the size of Texas and California combined, or
nearly five times the size of the United Kingdom, the center
said. It is more than double the drop between 2005 and 2002,
the previous record-holding year.
"That's a dramatic change in one year," Meier said of this
year's sea ice decrease. "Certainly we've been on a downward
trend for the last 30 years or so, but this is really
accelerating the trend."
The minimum amount of ice occurred on Sunday and freezing
has already begun in some places, according to satellite
imagery used by the center.
EARTH'S AIR CONDITIONER
Melting sea ice, unlike the melting glaciers of Greenland
and Antarctica, does not contribute to global sea level rise,
much as an ice cube in a glass of water does not make the level
of liquid rise when it melts.
However, without the bright white of sea ice to reflect the
sun's rays, the Earth loses what some climate scientists call
its air conditioner. The less ice there is, the more dark water
there is to absorb the warming solar radiation.
This year's record was caused by a "perfect storm" of
interacting factors, Meier said by telephone.
These included a long-running high pressure system that
kept skies cloudless over the Arctic, along with a circulation
pattern that pushed ice out of the Arctic towards Greenland,
instead of letting it circle around the Beaufort Sea north of
Alaska as it usually does.
Also, there was thinner ice to begin with, Meier said.
While this particular year's ice minimum cannot be directly
attributed to anthropogenic -- human-caused -- global climate
change, the trend that brought it about can, he said.
"This year, the reason why (the ice) was so low was not
because there's more anthropogenically generated carbon dioxide
dumped in the last year, it's because of this high pressure ...
but you can't really explain the overall trend without invoking
anthropogenically global warming," Meier said.
He also noted that the decrease in Arctic sea ice was
forecast in models used by the U.N. Intergovernmental Panel on
Climate Change, which this year said with 90 percent
probability that global warming exists and that human
activities contribute to it.
However, the sea ice is diminishing much faster than any of
the models predicted, Meier said.
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