Climate models predict that the rate of glacier loss will accelerate to 3000 per year by 2040, even if nations achieve their emission reduction targets. This could result in 79 percent of the world's glaciers vanishing by 2100 under current policies, threatening water supplies for billions and contributing to sea-level rise. Researchers emphasize the potential to save many glaciers by limiting warming to 2 degrees Celsius.
Researchers led by Lander van Tricht at ETH Zurich in Switzerland have modeled the fate of the planet's 211,000 glaciers using various global warming scenarios. Currently, around 1000 glaciers disappear annually, with at least 4000 lost over the past two decades. The study forecasts this rate climbing to 3000 per year as early as 2040, peaking around mid-century before slowing as smaller glaciers vanish first.
Under current climate policies, which align with 2.7 degrees Celsius of warming above pre-industrial levels, 79 percent of glaciers would be gone by 2100. Limiting warming to 2 degrees Celsius could reduce losses to 63 percent, while 4 degrees Celsius of warming would see 91 percent disappear. Earlier estimates suggested half of glaciers would melt even at 1.5 degrees Celsius, but this analysis revises that figure to 55 percent.
The consequences extend beyond ice. Glacier melt is expected to raise sea levels by 25 centimeters this century. It also endangers water security for two billion people in regions dependent on mountain snow and ice, including those near Himalayan rivers used for irrigation. Increased glacial lake outbursts could heighten flood risks, as seen in the 2023 incident in India that claimed 55 lives.
Regional impacts are stark. Western Canada and the contiguous United States face near-total glacier loss by 2100, stripping Glacier National Park in Montana of its namesake features, potentially leaving only small ice patches. The Alps will similarly be almost glacier-free, prompting communities to mourn their passing. In 2019, Matthias Huss of ETH Zurich and others climbed to the remnants of the Pizol glacier to highlight human connections to these features.
"We're going to lose many of our glaciers, but we have the ability to preserve a lot of them as well," says David Rounce of Carnegie Mellon University. Huss adds, "We are attached to our glaciers. If they are gone, it matters to us." The findings underscore the urgency of emission cuts to mitigate these irreversible changes.