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Canada’s glaciers will melt faster than ever in the next few centuries. Research by meteorologists of Utrecht ľ�ϸ���Ӱ�� in cooperation with the Royal Netherlands Meteorological Institute and American colleagues has shown that 20% of the Canadian glaciers may have disappeared by the end of this century, which would amount to an additional sea level rise of 3.5 cm. The results of the research have been published in Geophysical Research Letters.

The researchers developed a climate model for the island group to the north of Canada with which they simulated the shrinking and growing of glaciers. It appeared that the model correctly ‘predicted’ the values measured over the last ten years. The researcher then used the model to determine the effect of global warming on Canada’s glaciers.

Irreversible

The most important result of this research is that it has shown the irreversibility of the melting process, according to meteorologist and lead author Dr Jan Lenaerts of Utrecht ľ�ϸ���Ӱ��. “Even if we only assume moderate global warming, it is still highly likely that the ice is going to melt at an alarming rate. The chances of it growing back are very slim.”

Self-reinforcing effect

One of the major causes of irreversibility lies in the fact that snow melting on tundra’s and sea ice melting around the glaciers actually reinforce regional warming, which has disastrous effects on the glaciers of Northern Canada. Snow and sea ice reflect the sunlight, and when the snow and sea ice have disappeared, a large part of the sunlight will be absorbed by the land and the sea, which will significantly increase the local temperature.
In the scenario in which 20% of Canada’s glaciers have disappeared by the end of this century, the average global temperature increase will amount to 3 centigrade. However, the rise in temperature around the Canadian glaciers will equal 8 centigrade. Lenaerts emphasises that this is not an extreme scenario.

Sea level rise

Canada’s glaciers are the third largest ice body in the World after Greenland and Antarctica. Should the glaciers melt completely, the global average sea level will rise by 20 centimetres. Since the year 2000, the temperature in this area has risen by 1 to 2 centigrade, and the ice volume has already significantly decreased. If a quarter of the glaciers have melted by the end of this century, this leads to an additional sea level rise of 3.5 cm. Additional, because the ice of Greenland and Antarctica is also melting. “Most attention goes out to Greenland and Antarctica, which is understandable, because they are the two largest ice bodies in the world. However, with this research we want to show that the Canadian glaciers should be included in the calculations”, says co-author Professor Michiel van den Broeke of Utrecht ľ�ϸ���Ӱ��.

Publication

Irreversible mass loss of Canadian Arctic Archipelago glaciers Jan T. M. Lenaerts*, Jan H. van Angelen*, Michiel R. van den Broeke*, Alex S. Gardner, Bert Wouters, Erik van Meijgaard
Geophysical Research Letters, DOI: 10.1002/grl.50214
*Researchers at the Institute for Marine and Atmospheric Research of Utrecht ľ�ϸ���Ӱ��.

This research has been supported by, a research programme of the European Union. The objective of Ice2Sea is to gain more insight into sea level rise as a result of melting ice volumes.

More information

• Nature publication of May 2011:
• Monica van der Garde, Press Officer of the Faculty of Science: m.vandergarde@uu.nl, 06 13 66 14 38.