According to a new scientific study, the Frank Mackie glacier complex, which includes the spectacular Salmon Glacier near Stewart, will have virtually disappeared between 2075 and 2100 in both low and high climate change scenarios.
The Nature Geoscience paper, done by UBC and involving the contributions of UNBC geography professor and glacier change specialist Brian Menounos, modeled future melt scenarios based on several projections of increasing greenhouse gas emissions and found that about 50 per cent of glacier mass will melt by 2100 in the coast mountains and 75 per cent in other B.C. ranges.
“A lot of that is projected by us to undergo decline even under the more conservative emissions scenarios,” said Menounos of the Salmon Glacier complex and other glaciers closer to Terrace because they have relatively little ice mass compared to more northern ones.
The top photo shows the estimated depletion of the Frank Mackie glacier complex that includes the Salmon Glacier if climate change is constant. The bottom photo shows the worst case scenario for the glacier. Photos courtesy Brian Menounos, Professor of Earth Sciences and Canada Research Chair in Glacier Change Geography, UNBC.
River levels are maintained by melting of the snowpack throughout the summer, but it’s later in the season that waters from glaciers supplement this flow and cool the streams, he said.
Further south in the Skeena watershed, local glacier expert Matt Beedle, who worked with Menounos on his PhD, says that a smaller amount of the watershed is glacier-fed.
“The Skeena watershed has a glacierized area (current glacier cover) of about 1.5 per cent,” said Beedle.
“This is not a large amount, and means that the Skeena will not be dramatically altered in the coming decades by loss of its glacier.”
But this note of optimism is tempered when other rivers that feed into the Skeena are taken into account.
“Subdrainages within the Skeena watershed have a glacierized area of up to 12 per cent. Loss of these glaciers in the coming decades will result in increased water temperatures and decreased flows, and will stress our invaluable salmon runs.”
He said that the Kitsumkalum, Zymoetz (Copper) and Exchamsiks rivers are such rivers than could suffer as glaciers that feed them all but disappear over the coming century.
“Glacier melt in dry, hot summers acts as an important buffer – bringing fresh water to our rivers when we need it most,” said Beedle.
“This new research shows the magnitude and timing of the glacier loss we will experience in the coming decades,” he added.
The researchers hope that the trends will be reversed and forecasts will be proven wrong if the world transitions to non-carbon emitting forms of energy production in the coming decades.
Up around Stewart the recession of at least one glacier is easily apparent.
According to City of Stewart administrator Tara Barker, the Bear Glacier which you see driving through the mountains on the highway into Stewart has shrunk dramatically.
“Just in the last 10 years, everyone notices it used to come right up to the highway before there was the pool there,” she said of the viewing area near town.
As for the Salmon Glacier, she said the size of it would make melting less apparent. “What you see is just the toe of it,” she said.
“It’s definitely one of the biggest attractions when people come for their first time, their first question is, “where is the Salmon Glacier?”
According to the new projections, the answer in 100 years will be: it’s gone.