Western Canada: Glacier study underscores risk from climate change

Good morning. It’s James Keller in Calgary.

Scientists and environmentalists have long been warning about the future of Western Canada’s glaciers, and a new study underscores just how dire the situation could be: Even in optimistic scenarios, the world could lose between half and two-thirds of its glaciers by the end of the century.

Some regions in Canada and around the world are set to lose their glaciers completely and contribute much greater to a rise in sea levels. As Justine Hunter reports, this would have wide-reaching consequences – from Alberta towns that rely on glacial runoff for their water supply to the coastal wildlife dependent on salmon returns.

The authors of the study, published Friday in the journal, Science, ran simulations based on a range of changes in global temperatures. And while governments say they are working to keep the increase to 2.4 C, the predicted loss of half the world’s glaciers could happen even if that is kept to 1.5 C.

Although glaciers in Western Canada are already in retreat, the study shows the pace could accelerate in 2040. The impact will be acute for B.C.’s watersheds and the aquatic life that depends on them. And there could be disastrous effects.

Consider, for example, the record-breaking drought that hit in southern B.C. last year. While it was deadly for Pacific salmon in B.C., summer runoff of water from glaciers provided some relief and mitigated the damage. But once the glaciers are gone, they will take that critical safeguard with them and put already delicate ecosystems in greater peril.

According to biologist David Clough, the river system is fragile, because of industrial logging, agriculture and urban development: “There’s no shock absorber,” he said.

The glacier study says that the world is now on track for a 2.7 C temperature rise since pre-industrial levels. That would mean losing 32 per cent of the world’s glacier mass by 2100 – or 48.5 trillion metric tons of ice – as well as 68 per cent of the glaciers disappearing.

The study says that would increase sea level rise by 115 millimetres, in addition to seas already getting larger from melting ice sheets and warmer water.

With files from The Associated Press