Geography professor Brian Menounos, University of Northern British Columbia (UNBC), has been studying glaciers for 20 years. These enormous expanses of ice fascinate him, even if he knows their days are numbered.
I feel like a funeral director talking about the extinction of the glaciers, he says.
Twice a year, the scientist and his team fly over nearly 3,000 square kilometers of glaciers in British Columbia and Alberta to assess their condition.
He explains that several glaciers have melted faster this year due to a series of weather events such as the heat dome that hit western Canada in June.
The heat has increased the risk of forest fires. Fires then started, which produced black carbon, which was deposited on the glaciers. Snow and ice on the surface of glaciers reflect heat, but when darkened, it absorbs more of the sun’s energy, explains the scientist.
The holder of the Canada Research Chair in Water Resources and Climate Change at the University of Saskatchewan, John Pomeroy, adds that the black carbon deposited on glaciers contains various substances, including algae that maintain soot particles in place for years and prevent the glacier from reflecting heat.
The proliferation of these algae […] is a consequence of climate change that we did not anticipate, he said.
Glaciers in the Rockies, like the Peyto Glacier, located about 90 kilometers northwest of Banff, are therefore melting at an alarming rate. In 2021 alone, the latter fell 200 meters.
We believe it will no longer exist as a glacier by the end of the decade, deplores John Pomeroy.
Glaciers, essential to ecosystems
The scientist emphasizes, however, that glaciers are essential for the proper functioning of the ecosystems that surround them.
He explains that in normal times, part of the snow that settles on glaciers during winter turns into ice, while another melts and flows into rivers, then into the Atlantic oceans, Arctic and Pacific.
This water is essential, since it cools the waterways on which the survival of fish species, such as trout, depends.
Bringing water from glaciers through streams is also essential for irrigation and municipal water supplies in late summer when rainfall decreases.
The problem is that today, due to global warming, most of the snow is melting, which prevents new ice from forming.
” We no longer feed the glaciers. “
If some rivers receive more water due to the accelerated melting of glaciers, in the long run, these water reserves are doomed to disappear, he adds.
Even if we stabilized our greenhouse gas emissions now, glaciers would continue to melt because they have a memory and they continue to feel the impact of previous years., deplores Brian Menounos.
No more extreme weather events
John Pomeroy believes that melting snow earlier in the year and reduced water flow from glaciers will lead to increasingly long and drier summers in Western Canada.
The soils will be drier. There will be more forest fires and less water in streams by the end of summer, he explains.
He adds that increased precipitation in winter, caused by climate change, will lead to more flooding.
Did what we saw in British Columbia this year [à savoir] a summer of drought and forest fires and flooding in winter, will become the norm? This is what worries us, he said.
With information from Marie Chabot-Johnson