A fifth of Canada’s Arctic glaciers may disappear this century, raising sea levels as their retreat becomes harder to reverse, scientists said.
An increase in average global temperatures of 3 degrees Celsius (5.4 Fahrenheit) would be sufficient to melt the ice from glaciers on Canada’s northern islands, according to a statement e-mailed today by the British Antarctic Survey, whose researchers contributed to the study.
The Arctic has become a harbinger of climate change, with the effects of higher global temperatures occurring faster in the frozen north than elsewhere. The sea ice that covers the Arctic Ocean shrank to a record low in September according to satellite records dating back 33 years, while researchers have also documented retreating glaciers on Greenland.
“Even if we assume that global warming is not happening quite so fast, it is still highly likely that the ice is going to melt at an alarming rate,” lead author Jan Lenaerts, a researcher at Utrecht University in the Netherlands, said in the statement. “The chances of it growing back are very slim.”
Should the world warm by an average of 3 degrees, the Arctic is likely to get 8 degrees hotter because of so-called feedback effects, according to the scientists. As snow and ice recede, they expose dark ground and sea, which absorbs sunlight rather than reflecting it, amplifying local temperature changes.
Lenaerts said the scenario depicted by the research isn’t “extreme.” A World Bank study in November indicated a 4-degree jump in temperature this century, while the International Energy Agency said the chances of containing warming below 2 degrees may be erased by 2017 as planned power plants come on line.
Losing 20 percent of the glaciers on Canada’s northern islands would add 3.5 centimeters (1.4 inches) to sea levels this century, according to the research, which will be published this week in the journal Geophysical Research Letters.
The European Union-funded research was carried out by ice2sea, a program based at the British Antarctic Survey in Cambridge, England, which brings together research from 24 institutions from around the world.