On Thin Ice
by deirdre Kelly
photography by mike Ford
If ice fishing is your thing, then this bit of chilling news just might make your heart sink. Climate change is preventing many Canadian lakes from freezing over in winter, putting a damper on a favourite – and important – activity for rural lakeside communities across the nation. But cold-weather anglers aren’t the only losers here.
According to a new study out of York University, a lack of winter ice can increase evaporation rates and the possibility of algal blooms, threatening local ecosystems. The threat is very real, says postdoctoral fellow and York alum Alessandro Filazzola (BSc ’12, PhD ’18), the study’s lead.
“Lake freezing is important for maintaining the quality of fresh water that would be put at risk with the loss of winter ice.”
With a team of researchers at York, Filazzola examined nearly 80 years of lake-ice data from 122 lakes across the Northern Hemisphere. After counting the ice-free years, the team determined that the average number of ice-free winters has more than tripled since 1979. The situation is predicted to worsen with time.
“We found that warmer winters were closely related to the number of lakes going ice-free. Under current greenhouse gas emission scenarios, we expect ice-free years to triple again by the end of the century.”
The study, published in Geophysical Research Letters, has broad ecological, cultural and economic implications, especially for lake communities where the ice supports tourist activities like winter skating, ice-carving festivals and ice-fishing derbies with large cash prizes. Because winter ice often acts as a natural bulwark against powerful seasonal waves, its absence is also said to be responsible for property damage and land erosion in cottage country.
But freeze that thought: it’s not all bad news. Lower carbon emissions could significantly limit ice cover loss for many lakes in northern latitudes. This would be crucial for Canada, home to the most lakes of any country worldwide. “Ice in Canada is iconic,” Filazzola says. “If not remedied, its loss will be the making of a national tragedy.” ■