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The West Antarctic Ice Sheet, whose melt may be
responsible for 10 percent of the sea-level rise caused by climate
change, is warming twice as quickly as previously thought, a study said
Sunday.
A re-analysis of temperature records from 1958 to 2010 revealed an
increase of 2.4 degrees Celsius (36.3 degrees Fahrenheit) over the
period — three times the average global rise.
The increase was nearly double what previous research had suggested, and
meant this was one of the fastest-warming regions on Earth, according to
paper co-author David Bromwich of the Byrd Polar Research Center.
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“Our record suggests that continued summer warming in West Antarctica
could upset the surface balance of the ice sheet, so that the region
could make an even bigger contribution to sea-level rise than it already
does,” he said.
Scientists believe the shrinking of the West Antarctic Ice Sheet is
responsible for about 10 percent of global warming-related sea-level
rise, which if unchecked threatens to flood many coastal cities within a
few generations.
The sheet, a huge mass of ice up to four kilometres (2.5 miles) thick
that covers the land surface and stretches into the sea, is melting
faster than any other part of Antarctica.
Data records kept at Byrd Station in the central West Antarctic had been
incomplete.
Since being established in 1957, the research station has not been
consistently occupied and has seen frequent power outages, especially
during the long polar night, when its solar panels cannot recharge.
Bromwich and a team from several US-based research institutions used
weather data from different sources to plug holes in the Byrd data and
corrected calibration errors.
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The updated log was published in the journal Nature Geoscience.
“Aside from offering a more complete picture of warming in West
Antarctica, the study suggests that if this warming trend continues,
melting will become more extensive in the region in the future,” said
Bromwich.
The UN Intergovernmental Panel on Climate Change in 2007 had projected
sea level rise of 18 to 59 centimetres (seven to 23 inches) worldwide by
the year 2100.
But a study by the US National Research Council said in June the actual
rise could be two to three times higher, with polar ice-cap melt
speeding up the process. |