Meltwater flows through a glacier cave in front of the Morteratsch glacier in Switzerland.
Lander Van Tricht
Currently, about 1,000 glaciers are lost each year, a figure that could rise to 3,000 a year by as early as 2040, even if countries meet their carbon reduction targets.
At least 4,000 glaciers have melted over the past two decades. Lander Van Tricht from ETH Zurich in Switzerland and his colleagues used climate models to predict what would happen to the world's 211,000 glaciers over the next century under different global warming scenarios.
Current climate targets put the world on track to warm 2.7°C above pre-industrial temperatures this century. This would mean that by 2100, 79 percent of the world's glaciers will disappear. However, if humanity limits global warming to 2°C, 63 percent of glaciers will disappear.
“We will lose many of our glaciers, but we have the opportunity to preserve many of them,” says David Rounce from Carnegie Mellon University in Pittsburgh, Pennsylvania, who worked on the study.
If countries don't meet their targets and the world warms by 4°C, 91 percent of glaciers will be lost.
Glacier melting is predicted promote growth sea level by 25 centimeters this century. It would also undermine the summer melt water that many regions rely on for irrigation. Two billion people live in watersheds fed by mountain snow and ice, many of which are located near rivers that flow from Himalayan glaciers.
Melting ice also means there will be more frequent floods caused by the sudden release of water from a glacial lake, like the one killed 55 people in India in 2023.
Previous research has shown that half of all glaciers will melt this century even if humanity limits warming to 1.5C, the most ambitious goal of the Paris Agreement. The current study refines those estimates, finding that 55 percent would be lost with such warming.
It also predicts the rate of glacier loss by year and region. This pace will peak around mid-century and then slow as smaller mountain glaciers disappear and larger ones remain, such as in the Arctic and Antarctica.
“The bigger ones just take a long time to break the ice, [so] they will disappear later,” says Van Tricht.
Western Canada and the contiguous United States will lose almost all glaciers by 2100, according to current climate targets. In a blow to tourism, Montana's Glacier National Park will be largely devoid of glaciers, although some may remain as miniature glaciers or ice patches, according to an upcoming report. research from the US Geological Survey.
The Alps will also be almost bare. Communities are already holding glacier funerals, and the Global Glacier Victims List website collects their stories. Matthias Huss from ETH Zurich, who worked on the study, and 250 others climbed the remains of the Pizol glacier in 2019.
They came to say goodbye and also to tell the public: “We are tied to our glaciers,” Huss says. “If they're gone, that's important to us.”
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