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Glaciers disappearing

Coast Mountain glaciers are being hammered

By Lynn Martel

The Garibaldi glaciers are among the fastest disappearing glaciers in the world, says Dr. Shawn Marshall, University of Calgary associate professor in glaciology and climatology.

“The Coast Mountain glaciers are being hammered — what’s happening in the Canadian Rockies times two,” Marshall said. “That’s how much retreat is happening in the Coast Mountains.”

Marshall was one of several speakers at a two-day workshop held in Banff Oct. 10 and 11, titled Climate Change and its Affects on the Alpine. Organized by the Alpine Club of Canada as part of the club’s 2006 centennial celebrations, and running in conjunction with the general assembly of the International Mountaineering and Climbing Federation (UIAA), the workshop drew 40 participants from as far as Kimberley, Vancouver, Edmonton, Montreal and even South Africa and the Netherlands.

“Glaciers in the Coast Mountains are really vulnerable,” Marshall said. “Even a small change in temperature can change snow to rain. Some have lost 70 per cent of their size in this century. The Helm, Sentinel and the Garibaldi glaciers are among the most threatened in the world.

“There are many more glaciers scientists know little or nothing about, he added. But they do know the glaciers are disappearing.

“Scientists are witnessing profound changes in glaciers around the world, and from what we understand, these changes can be expected to continue and accelerate,” Marshall said. “Bigger icefields should hang in for a while, but with smaller outlet glaciers, we can’t give a number. Every glacier has its own story. Some pocket glaciers might melt back quickly, then retreat into sheltered cirques that never see the sun, which could stall their retreat. Others could disappear altogether.”

While scientists still have plenty of questions about how much and how fast glaciers around the world are melting, most agree on two things — glacial retreat is global, Marshall said, in both mountain and polar regions, and humans have been instrumental in causing those changes.

While western Canada’s glaciers aren’t retreating as quickly as those in other mountain ranges, such as Russia’s Caucasus, Peru’s Andes or Patagonia in Chile, Marshall said, there are very few places in the world where increases in snow accumulation are sufficient to offset warming temperatures and extend the life of glaciers, and Canada is not on the short list.

In order to be sustainable, a glacier needs to retain 60 per cent of the snow that falls on it each season. In recent years, many of western Canada’s glaciers have none of their winter snowfall left by the end of the season, leaving a surface of bare glacial ice that collects dirt, including particles from forest fires. The darker surface then absorbs increased sunlight, which in turn accelerates melting.

“If this is the new reality, these glaciers will be removed — gone from our landscape,” Marshall said.

While a shortened summer glacier ski season can spell negative effects for recreation-based economies, the picture is even less attractive in terms of water, said workshop speaker Dr. David Sauchyn, chief scientist at the Prairie Adaptation Research Collaborative at the University of Regina, and member of the United Nations Intergovernmental Panel on Climate Change.

“The biggest issue is water — where does the water come from?” Sauchyn said. “The eastern slope of the Rockies is the most critical landscape for all the prairie provinces — Saskatchewan, Manitoba and Alberta. Nearly the entire population of the prairie provinces gets its water from the Rockies.”

At the lower elevations, where extensive and reliable weather records have been kept for the past century, the snowpack has decreased 20 to 25 per cent over the last 20 years.

“At the lower elevations in the Rocky Mountains, historically the snowpack built up through the winter. It’s not doing that now,” Sauchyn said. “The winter is quite a bit warmer than it was a few decades ago. The most serious consequence of losing our winter is losing our snow. The disadvantage of rain is that when it falls, it runs off. Snow and ice are reliable sources of water. Believe it or not, there are advantages to having a cold winter.”

Those include cold winter temperatures killing off harmful pests, such as mosquitoes carrying West Nile virus and pine beetles, which are currently infesting forests across western North America.

While from some perspectives Canada is seen as a nation that stands to benefit the most as global temperatures rise, that’s an oversimplification, Sauchyn said. The same higher temperatures that lead to a longer growing season, will also likely lead to water shortages.

“The picture may appear rosy, but only to a point,” said Sauchyn, o ne of dozens of authors of the National Assessment on Climate Change, to be released in 2007 . “The growing season will be warmer and longer, but the bad news is more water will be stored in the air than in the ground. Water scarcity could constrain economic growth.”

Not to mention the ability of ski hills to make snow at lower elevations, he added.

One reason scientists don’t know how fast western Canada’s glaciers are melting is that while continuous and comprehensive research has been conducted at lower elevations, detailed scientific studies have been conducted in the high alpine for only the past 40 years.

“There are thousands of glaciers in Canada, more than any other country in the world, but only a handful that have been scientifically studied, and that didn’t really start until the mid 1960s,” Marshall said.

Ski hills record snowfalls throughout B.C. and Alberta, and avalanche researchers annually compile high quality records in Glacier National Park, where members of the Vaux family collected comprehensive data in the late 1800s and early 1900s, but all of that information is seasonal.

“We don’t have high quality, continuous, reliable, quality controlled information,” Marshall said.

Despite the shortage of information on snow levels in the high alpine — due to a combination of factors, including funding and the logistics of accessing research plots in the high alpine for necessary regular maintenance — among the scientific community, one thing is no longer being debated.

“There is no more uncertainty about climate change than there is about economics,” Sauchyn said. “But somehow scientists are held up to a higher standard. But the debate is over. The climate is changing, and it’s very clear that we are at least partially responsible.”




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