Antarctic ice melt may accelerate sea level rise
The ice discharge from Antarctica could become the largest contributor to sea level rise much sooner than previously thought, says a study.
"If greenhouse gases continue to rise, ice discharge from Antarctica could raise the global ocean by an additional 1-37 centimetres in this century already," said lead author Anders Levermann, a climatologist and professor at the institute for physics and astrophysics of Potsdam University, Germany.
"Now this is a big range - which is exactly why we call it a risk," he added.
Antarctica currently contributes less than 10 percent to global sea level rise and is a minor contributor compared to the thermal expansion of the warming oceans and melting mountain glaciers.
It is Greenland and especially the Antarctic ice sheets with their huge volume of ice that are expected to be the major contributors to future long term sea level rise, the study noted.
According to the study, the computed projections for this century's sea level contribution are significantly higher than the latest projections by the Intergovernmental Panel on Climate Change (IPCC) on the upper end.
"Even in a scenario of strict climate policies limiting global warming in line with the 2 degrees Celsius, the contribution of Antarctica to global sea level rise covers a range of zero to 23 cm," researchers emphasised.
While the study signifies an important step towards a better understanding of Antarctica in a changing climate and its influence on sea level change within the 21st century, major challenges still remain.
"Datasets of Antarctic bedrock topography, for instance, are still inadequate and some physical processes of interaction between ice and ocean cannot be sufficiently simulated yet," Levermann added.
Rising sea level is widely regarded as a current and ongoing result of climate change that directly affects hundreds of millions of coastal dwellers around the world and indirectly affects billions more that share its financial costs.
"Pulling together all the evidence it seems that Antarctica could become the dominant cause of sea level rise much sooner," Levermann concluded in a paper that appeared in the journal Earth System Dynamics.
(Posted on 14-08-2014)