UK experts say glacier fall not climate related
Date: 13-May-02
Country: UK
Author: Stefano Ambrogi
Disintegration of the Ross ice shelf on Thursday in the Ross Sea follows the collapse in March of the so-called Larsen B ice shelf in the Weddell Sea near Chile, also in Antarctica. That ice shelf was the size of a small European country.
"From the size of it, 41 nautical miles (76 kilometres) long and 4 nautical miles wide, it sounds as though it is a normal 'calving' event from the ice front," BAS glaciologist Chris Doake told Reuters.
Doake said that was in contrast to the Larsen B's break up in a different part of Antarctica and under a different set of circumstances which were linked to rising global temperatures.
"But this Ross ice shelf collapse isn't climate related," he said.
Calving is a process by which polar ice caps move and fracture the ice into sometimes large fragments that float loose into the ocean.
Mike Hulme, Director of the Tyndall Centre, a climate change research organisation at the University of East Anglia, agreed with Doake.
"I don't think in itself it is particularly significant. Ice shelves have to break apart and so in that sense it is a normal process," he said.
Hulme said that if one was looking for evidence for global warming then the most authoritative planetary index one would need to look at was one that traced movements in surface temperature rather than developments in ice shelves.
Green groups immediately pointed to the disintegration as evidence that emissions of greenhouse gases are pushing up global temperatures and causing ice caps to melt.
One global warming expert with the National Environment Trust in the United States said on Thursday that for meteorological reasons glacier collapses are one of the first indicators of rising planetary temperatures.
Last week environmental group Friends of the Earth (FOE) said it was rash to suggest there was no link between rising global temperatures and yet another glacier collapse.
"What distinguishes naturally occuring events from climate change?" said FOE climate change campaigner, Roger Higman.
"Surely the question is whether rising temperatures might increase the rate of collapse - both glacial falls are consistent with the fact that that part of the world is getting warmer and the ice sheet is melting as a result," he said.
But Greenpeace International doubted whether warming was behind the latest fall.
"The Ross ice system spews off icebergs all the time," climate change advisor Steve Sawyer told Reuters.
The Antarctic Peninsular has warmed by 2.5 degrees Centigrade over the past half century, far faster than elsewhere on the ice-bound continent or the rest of the world.
(additional reporting Matt Daily in Amsterdam).