Click the link to read the article on the CBC News website (Christy Climenhaga). Here’s an excerpt:
A drive through the Canadian Rockies will treat you to views of blue mountain lakes, wildlife and, of course, glaciers. But with our changing climate and warming winters, glaciers are receding at an alarming rate in Canada and around the world. Globally that will impact sea levels while here on the Prairies, the loss of our Rocky Mountain glaciers will affect our freshwater supply.
“We’re past the tipping point for the glaciers in the Canadian Rockies,” says John Pomeroy, professor and Canada Research Chair in water resources and climate change at the University of Saskatchewan.
Pomeroy says over the last few decades, almost all the world’s glaciers have shrunk and the rate of decline is accelerating.
“Even if somehow, magically, we’re able to stop global warming tomorrow and return the atmosphere to more normal CO2 concentrations, we would lose most of the Rockies’ glaciers.”
High rate of melting
Warmer winters aren’t the only factor driving glacier melt. A deep purple algae, likely linked to forest fires, has been collecting on Canadian glaciers over the last few decades. The algae looks like dark dust and causes the glacier to absorb solar energy, causing even more rapid melting.
“I went through my photographs in the 1970s and ‘80s just to make sure I wasn’t dreaming,” says Pomeroy.
“Glaciers were very, very white back then. And they’re not like that now.”
Strain on our rivers
What does all this mean for our water supply? Kavanaugh says glaciers keep our rivers flowing when other water sources dry up, like late summer when the snowmelt is gone and rainfall is at its weakest.
“They carry us through the hottest months into the winter.”
During particularly hot and dry years — like last summer, for example — glacier-fed rivers can actually see higher-than-normal flow.
“Though the streams that relied on the snowpack and groundwater dropped to very, very low levels, the streams that were fed by glaciers — like the Athabasca River or the North Saskatchewan — had very high flows,” Pomeroy says
The next few decades could be marked by high flows in our glacial rivers, which will continue as long as the glaciers are voluminous enough to contribute a lot of water, Kavanaugh says.