Antarctic ice sheet temperture increasing
2012-12-24 16:04
Paris - The West Antarctic Ice Sheet, whose melt may be
responsible for 10% of the sea-level rise caused by climate change, is warming
twice as quickly as previously thought, a study said on Sunday.
A re-analysis of temperature records from 1958 to 2010
revealed an increase of 2.4°C 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 Centre.
"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% 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 4km 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.
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 59cm 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.
- SAPA
