Wildfires devastated Jasper. The soot and ash are putting Alberta's glaciers at risk, scientists warn

As the devastating fires around Jasper National Park filled the sky with smoke and ash, John Pomeroy was thinking of the region's famous — and melting — glaciers. 

Just a week before the fires, the University of Saskatchewan hydrologist had been to the Athabasca Glacier located about 100 kilometres south of the town of Jasper, to collect measurements. His team found that the glacier had already melted about three metres in thickness since last September. "Which is plenty for a mostly winter period," he said.

What Pomeroy's been seeing at the glacier is not the bright white, snowy landscape they're often associated with — but rather a grimy and darkened surface. He believes it's likely that the glacier has been further darkened by the ash and soot from the latest fires.

And the grime doesn't just look bad. According to Pomeroy, the glacier is melting faster because darker surfaces absorb more solar radiation than a clear, white surface would.

"And the combination of that, along with the hot temperatures, puts a glacier into a death spiral."

According to measurements collected by Pomeroy's team, the Athabasca Glacier melted nearly nine metres last year, a record for the glacier that has been visited by millions of people and is an iconic stop on Alberta's scenic Icefields Parkway.

Pomeroy is worried that, in addition to the summer's soaring temperatures, all the extra soot from the recent wildfires could result in that record melt being surpassed. 

"It puts these glaciers in a very perilous position yet again," he said. 

Meltwater from the thinning glacier feeds the Athabasca River, which runs more than 1,000 kilometres through Alberta and Saskatchewan. The Sunwapta River, a tributary of the Athabasca River that runs just below the glacier, has seen abnormally high flows since early July, which Pomeroy says indicates a faster than normal melt.

Researchers say melting glaciers in Western Canada could disrupt the flow of glacier-fed rivers, impacting water supply and hydroelectric power generation in the region.

Pomeroy has been studying Alberta's glaciers for decades, and has calculated just how much wildfire smoke and ash is affecting their melt.

His team examined the Athabasca glacier from 2015 to 2020, which included particularly severe wildfire seasons in 2017 and 2018. 

In a study published in 2022, Pomeroy and his team found that soot and ash from wildfires darkened the surface of the glacier, causing the ice melt to increase by up to 10 per cent.

The study also suggested the surface stayed dark beyond the fire season because algae had formed on the surface, feeding on the soot and thriving in warmer conditions — another consequence of climate change.