As the helicopter turned toward Peyto Glacier, located in the Park Ranges of the Canadian Rockies, John Pomeroy and his team of scientists gasped. <\/p>\n
Prof. Pomeroy, a distinguished professor and director of the Global Water Futures Observatories at the University of Saskatchewan, has studied the ice mass in Banff National Park since 2008, visiting several times a year to adjust weather stations and photograph changes. <\/p>\n
He is familiar with the glacier\u2019s rapid melting. It retreats tens of metres per year \u2013 80 metres in 2021 alone. But on the helicopter ride last September, he was stunned to see how much it had transformed since even his previous visit. <\/p>\n
\u201cYou think you know a place, and then you see it two months later and it\u2019s changed dramatically,\u201d Prof. Pomeroy said in an interview. \u201cIt\u2019s a very heartbreaking moment.\u201d<\/p>\n
The glacier looked to him like an inflatable toy losing its air, getting thinner while retreating horizontally. At the glacier\u2019s base, the icefield that once filled the valley had been replaced by a lake. The ice was also darker than one might have expected, owing to soot and ash from wildfires that have dramatically intensified in recent years \u2013 hastening the glacier\u2019s demise. <\/p>\n
A vanishing Alberta glacier attracts a new kind of last-chance tourism<\/a><\/p>\n As the country contends with longer and more destructive wildfire seasons, Canadians are growing accustomed to seeing summer skies turned grey and orange by smoke. This pollution has been linked to increased risks for heart health, cognitive function and dementia. But the damage extends beyond physiological well-being: ash drifting onto mountain glaciers is accelerating ice melt. <\/p>\n Clean glacier ice reflects about 30 per cent of solar radiation, but ice that has been darkened with soot and ash reflects around half of that, said Prof. Pomeroy. A research paper he co-authored in 2022 found that long after fires have been extinguished, the darkened surface of the glacier continues to accelerate ice melt by about 10 per cent<\/a>. <\/p>\n The broader implications are troubling. Glaciers supply drinking water, provide the headwaters for major rivers and keep streams flowing during periods of drought.<\/p>\n \u201cAnd, the conditions that cause the melt of the glaciers also make this planet very challenging to live on,\u201d Prof. Pomeroy said. <\/p>\n \u201cIt will mean air temperatures that occasionally exceed those which humans can survive in. It will mean immense droughts, punctuated by severe floods, and reliance on rain water,\u201d he added. \u201cAs the glacier ice makes its way into the oceans and causes sea level rise, that will inundate many of the coastal areas around the world.\u201d<\/p>\n Prof. Pomeroy\u2019s team also stumbled upon a somewhat unexpected finding. When they began recording glacial surfaces \u201cdark as a prairie field\u201d in 2016, Prof. Pomeroy knew that at least some of it was because of wildfires and figured it would eventually wash away with rain. But the darkness persisted, year after year. <\/p>\n In July, 2018, the team collected ice samples from Athabasca Glacier, located in Jasper National Park, and brought them to colleagues at the University of Saskatchewan\u2019s Toxicology Centre. There, scientists used a scanning electron microscope, among other instruments, to examine the environmental DNA.<\/p>\n \u201cWhat they found was amazing,\u201d Prof. Pomeroy said. The tests showed the expected soot and organic material, but also revealed a whole mix of life and microbes within the ice \u2013 algae, bacteria, fungi and viruses. \u201cSome of the algae were filamentous, and were actually holding the soot on to the ice crystals,\u201d he said.<\/p>\n