When a heatwave ripped through Western Canada in the summer of 2021, and Alberta’s temperatures soared above 40C, Shawn Marshall was cool in comparison.
As the climatologist studied a glacier in the Rocky Mountains, wind caressed the top of the ice shelf and chilled the air around him. Here, he noticed the glacier was darker in comparison to others he had seen in Canada.
Marshall believes the wildfires that tore through western North America in 2021 did more than burn down trees. The ash and carbon landed on the glaciers and made their icy surfaces darker, making them melt even faster.
The summer’s intensity was one of the worst Marshall had seen in the past 20 years. He said glaciers in B.C. and Alberta thinned by an average of two metres across their whole surface.
“Tons of those glaciers and icefields, they’re all thinning and retreating,” Marshall said. “This past summer, they were hammered.”
Marshall’s research suggests human-induced global heating has melted the glaciers in the Rockies more rapidly than any others in the country, which could be disastrous for Alberta’s water resources in the summer. So scientists and government officials now have to think of ways to either stop the glacial melting or replace their role in the environment.
Glaciers in the Rockies contribute to the flow of some of Alberta’s biggest rivers, including the Bow and Red Deer. The contribution is small, merely two per cent, but what they do for the province’s water supplies in the summer is what is most concerning about glaciers’ disappearances.
“Come July, August, September, the snow is gone from the mountains, largely. The rivers are fed by any rain we get and the glacier melt,” Marshall said.
“If it’s a dry summer and we’re not getting any rain, those glaciers are super important.”
In 2019, John Pomeroy, a hydrologist at the University of Saskatchewan, accompanied environmental activist Greta Thunberg to Athabasca Glacier to observe the damage from rising temperatures.
He said if and when the glaciers disappear, it could create problems for cities for water intake and treatment.
“It will create problems downstream because we’re still emitting sewage, but there’d be less water to dilute that,” he said.
The province’s agriculture would also suffer, with farmers struggling to irrigate their crops and feed their livestock, leading to higher prices in grocery stores, according to Pomeroy.
Kristina Miller, a geography PhD student at the University of Calgary who has worked with Marshall in the past, agrees glaciers are melting more quickly due to soot falling from wildfires.
“The smog and ash in the air, when that settles on a glacier surface, it makes it darker, and a darker glacier absorbs more energy,” she said. “And that energy translates into higher melt rates.”
The Rockies have been found to be warming faster than the rest of Canada, as well, in part due to their distance from bodies of water, Pomeroy said.
“Where you have big lakes, you don’t warm up quite as much,” he said. “When you’re close to the ocean, you don’t warm up quite as much.”
He explained that shorter snow seasons are another culprit, as snow cools the temperature down while also reflecting solar radiation back into space.
Government policies and scientific studies are now focused on what to do whenthese glaciers disappear. Changes to the province’s reservoir system would be a good start, according to Marshall.
“You have to have some sort of water storage that mimics what the glaciers do. I think that’s probably what we’ll need in the future,” he said.
Pomeroy added that the province’s reservoirs would need to hold enough water but leave space in the event of a flood. He said that the government would need to build man-made reservoir structures in the mountains.
Banff-based conservationist Harvey Locke opposes the idea.
“When you build dams, you destroy the hydrology and ecology of the system. They degrade the environment. I don’t want that at all,” he said.
“What I’d rather do is us get our act together and change our behaviours so that we don’t cause these problems.”
He said he’s worried about the Peyto glacier, one of the Rockies’ more notable formations, as it melted 10 times faster this past summer than it had in any other.
“We’re playing a very dangerous game of Russian roulette with Mother Nature right now. She will win. She always wins in geological or ecological time,” he said. “We have to tackle this climate change as a human species.”