Gayathri Vaidyanathan, E&E reporter
Published: Tuesday, April 7, 2015
Western Canada will lose most of its glaciers by the end of the century if humans continue emitting carbon at current rates, according to a new study in Nature Geoscience.
The glacial melt will raise global sea levels slightly, or by 6.3 millimeters, but it will fundamentally alter the water cycle in a region that has otherwise remained unchanged for thousands of years. The culprit: climate change.
"The climate is changing; it is becoming less favorable to glaciers. That is irrefutable," said Garry Clarke, an emeritus professor of glaciology at the University of British Columbia and lead author of the study, in a phone interview. "Glacier change is climate change -- there is no way to escape that."
The 17,000 glaciers in British Columbia and Alberta are an integral part of people's lives in both Canada and the United States. Some glaciers feed into the mighty Columbia River, which flows from Canadian headwaters into Washington and Oregon and supports 5 gigawatts of hydropower generation along the way. The study finds that most of the glaciers feeding the Columbia River could be gone by 2100.
Glaciers in the northwest corner of British Columbia would fare somewhat better, losing about 70 percent of their 2005 volume by the end of the century.
Bad news is the norm for the 200,000 glaciers on the planet, most of which are melting due to human-caused climate change and natural causes (ClimateWire, Aug. 15, 2014). They are expected to raise global sea levels by 1.3 feet by the end of the century.
Yet scientists have detailed records of just 350 glaciers. Studying glaciers is time-, cost- and labor-intensive, as research occurs in some of the harshest terrains on Earth.
To simplify the task, Clarke and his colleagues worked for eight years to create a computer model that simulates glaciers more accurately than others have in the past.
The model includes details such as the terrain under the glacier, the pull of gravity and the movement of ice. It assumes that humans would continue emitting carbon dioxide into the future at rates suggested by the Intergovernmental Panel on Climate Change.
A 'generic' model for glaciers?
The model also allows scientists to understand glaciers without physically being present on one. And it allows them to zoom out and evaluate impacts regionally, as well.
Clarke thinks the model could be used in regions such as the Himalayas, whose glaciers are particularly challenging to unravel. Some glaciers on the Karakoram Range are growing, while most on the Hindu Kush Himalayas and the Tibetan Plateau are in decline. The rate of decline has been difficult to pinpoint.
An interested Himalayan glaciologist could input into the model the topography of the Himalayas and the known glacier extents observed by satellites to get a sense of how they will evolve in the future, Clarke said.
"Still a big job, but at least we have set the path now," he said.
Andreas Vieli, a glaciologist at the University of Zurich, wrote in an accompanying editorial that the model is "highly generic" and could be used with data sets that are widely available.
"The methodology can therefore potentially be applied to a wide range of glacierized regions, or to reconstructions of past glaciations," Vieli wrote.
As for Clarke, he hopes that his labor of the past decade proves useful in communicating the threat of climate change.
"Climate change is real, and we have responsibility to try to control our behavior in a way that won't be really harmful to the planet," he said.