24 Dec 2012

West Antarctic warming faster than thought

7:01 pm on 24 December 2012

The West Antarctic Ice Sheet is warming twice as quickly as previously thought.

AAP reports a new analysis of temperature records from 1958 - 2010 has revealed an increase of 2.4C 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 David Bromwich of the Byrd Polar Research Center.

"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 ice sheet, which is up to 4km thick, is melting faster than any other part of Antarctica.

West Antarctica holds enough ice to raise world sea levels by more than 3 metres if it ever all melted, a process that would take centuries.

Data records kept at Byrd Station in the central West Antarctic had been incomplete.

AAP reports that 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 research institutions in the United States used weather data from different sources to plug holes in the Byrd data and corrected calibration errors.

The updated log has been 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.