Canada glaciers face ‘big losses’ – ‘The processes that are currently ongoing will continue and be re-enforced, so the mass loss will increase in time’Posted by Jim at Thursday, March 07, 2013
By Jonathan Amos, Science correspondent
7 March 2013
(BBC News) – The glaciers of the Canadian Arctic Archipelago will undergo a dramatic retreat this century if warming projections hold true.
A new study suggests the region's ice fields could lose perhaps as much as a fifth of their volume.
Such a melt would add 3.5cm to the height of the world's oceans. Only the ice of Greenland and Antarctica is expected to contribute more.
The assessment is reported in the Geophysical Research Letters journal.
"This is a very important part of the world where there has already been a lot of change," said lead author Jan Lenaerts from Utrecht University, Netherlands.
"And it is all the more important that we talk about it because it has been somewhat overshadowed by all the news of Greenland and Antarctica," he told BBC News.
The Canadian Arctic Archipelago is a vast area, comprising some 36,000 islands.
Being so far north, much of region - some 146,000 square km - is covered by glaciers and ice caps (a type of ice field where glaciers flow off in many directions).
Current data indicates all this ice is already thinning at a rapid rate. Gravity measurements from space suggest the annual loss since 2003 has been running at about 70 billion tonnes, and it is accelerating.
With snowfall reasonably constant over the period, it appears that melt as a result of the 1-2-degree rise in air temperatures has tipped the ice out of balance. […]
"What we find is that the processes that are currently ongoing will actually continue and be re-enforced, so the mass loss will increase in time," said Dr Lenaerts.
"Our model estimates that in 2100, we have lost about 20% of the volume of Canadian Arctic Archipelago glaciers, which is a really large amount. It is equivalent to 3.5cm of global sea-level rise." [more]