At the end of the last ice age glaciers retreated across the North American continent, but not all the way North. In parts of Canada, especially northern areas, the glaciers remained.
A total of 17,000 glaciers remain in the provinces of British Columbia and Alberta. However, if current warming trends continue those glaciers could be much smaller or gone completely by the end of the current century.
That is the finding of a new paper published in the journal Nature Geoscience from researchers at the University of British Columbia. While ice loss will vary by area, the researchers estimate that 70 percent of the total glacier volume could be gone by 2100 which will have a significant impact on water supplies, power supplies and ecosystems for the region, and potentially the parts of the United States that border those provinces.
According to the study, glaciers in the dry interior of the Rocky Mountains could lost up to 90 percent of their volume, while those in the wet coastal mountains in northwestern British Columbia might only lose half.
“Most of our ice holdouts at the end of the century will be in the northwest corner of the province. Soon our mountains could look like those in Colorado or California and you don’t see much ice in those landscapes,” said Garry Clarke, professor emeritus in the Department of Earth, Ocean and Atmospheric Sciences at the University of British Columbia in a statement.
Researchers used a combination of computer models, climate simulations and observational data on individual glaciers to determine the potential climate impact.
In many cases, they report, the surface area of the glacier is not changing which gives the impression that it is stable. However, many of them are thinning at a rate of one meter per year. So, while the glacier covers the same terrain, the ice is getting thinner year over year.
“Most glaciers are only 100 or so metres thick. They’re losing volume but this loss we’re seeing right now is a bit hidden,” said Clarke.
The glaciers of Alberta and British Columbia contribute energy through hydroelectric power, as well as contributing the the water supply, tourism and agriculture. The losses in these areas may be offset to a degree by the increased rainfall that the region expects due to climate change, however the increase in water temperature could have a serious adverse impact on freshwater ecosystems.
“These glaciers act as a thermostat for freshwater ecosystems. Once the glaciers are gone, the streams will be a lot warmer and this will hugely change fresh water habitat. We could see some unpleasant surprises in terms of salmon productivity,” said Clarke.
The researchers used greenhouse gas emission predictions used by the Intergovernmental Panel on Climate Change (IPCC) to create the models used for their predictions. The primary factor contributing to the estimated emissions is carbon dioxide from the burning of fossil fuels.
Predictions of emissions are based on current estimates. While a change in emissions could alter the impact on glaciers, emissions are currently still increasing annually.
In addition to the University of British Columbia team, researchers from the University of Northern British Columbia, the University of Iceland and the Pacific Climate Impacts Consortium also contributed to the report.