Rising seas threaten west Antarctic

There’s a ‘big gorilla hiding the closet’ whose collapse could have a dramatic effect on sea levels, according to Australian researchers.

Dr Bradley Opdyke, a paleoceanographer from the Australia National University (ANU) believes the West Antarctic Ice Sheet (WAIS) could partially collapse within 20 years, resulting in a dramatic jump in sea levels.

His talk on glacial cycles and the WAIS was presented earlier this month at the Imagining the real: life on a greenhouse earth conference held in Canberra.

“The 900-pound gorilla hiding in the closet is Antarctica. We have evidence that it is not a stable beast,” Opdyke says.

He says the WAIS is inherently unstable, and the current rate of sea level rise is placing it at risk.

… By examining conditions during previous events, Opdyke predicts that a sea level rise of 50 to 100 centimetres above the 1920 level may be enough to “unpin” the ice sheets, leading to a collapse of the WAIS.

“Since 1920, sea levels have risen about 23 centimetres,” he says.

“We’re now experiencing an annual sea level rise of 3.3 millimetres, from alpine and Greenland glacier ice melt and thermal expansion of the oceans.

“In 10 years time we expect the rise to be over 6 millimetres per year and by 2028, over 1 centimetre per year.”

ABC