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A new ETH Zurich map assigns each glacier its own projected disappearance window
The Global Glacier Extinction Explorer turns a Nature Climate Change assessment into per-glacier disappearance windows under different warming levels. One Swiss glacier has already vanished inside the window its models drew.
The Scientist · Science desk
What happened
- Researchers launched the Global Glacier Extinction Explorer, a website where anyone can look up whether and approximately when an individual glacier is projected to disappear under different warming levels.
- The map draws on a Nature Climate Change study led from ETH Zurich and Vrije Universiteit Brussel, described as the first global assessment of the disappearance of individual glaciers.
- That study used projections from three global glacier models published in The Cryosphere in 2024, and defined peak glacier extinction as the period when annual disappearances reach their maximum.
- Preliminary observations suggest 2026 could be one of the worst years for Alpine glaciers since systematic measurements began, with final end-of-summer readings still being collected.
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Why it matters
- capability A municipality or a ski operator can now query a named glacier under a chosen warming level, which aggregate mass-loss figures never allowed.
- decision For Alpine cantons the difference between the 2.7C and 4C scenarios is 110 remaining glaciers or 20, a spread wide enough to change what a tourism or water asset is worth planning for.
- precedent Publishing dated windows per glacier means every future extinction declaration becomes a score against the model, and the researchers will be held to the ones that miss.
The one projection in the study that can already be checked belongs to Bella Tola, a small glacier near Saint-Luc in Switzerland. It was declared extinct in August 2026 after almost completely disappearing, and the study had projected it to go between 2026 and 2029 [11]. The observed date sits at the earliest edge of that window [4]. Urirotstock was also declared extinct this summer [12]. "Bella Tola is particularly striking, as its observed disappearance falls directly within the extinction window projected by our models," said Lander Van Tricht, the lead author [18]. One glacier is one case, and a glacier already worn down to a remnant is the easiest kind of date to get right. I would not call the match a validation of the global set.
The dates come out of decades of accumulated loss. "The disappearance of a glacier is not the result of a single warm summer, but the culmination of decades of cumulative mass loss," said co-author Harry Zekollari of VUB, who added that "insufficient snowfall and strong summer melt gradually reduce a glacier until it can no longer sustain itself" [15]. Extreme melt years such as 2022 or 2026 "can, however, accelerate this final stage," he said [16]. In the Alps this year the ingredients were low winter snow accumulation and several summer heat waves [14].
At the peak of extinction, around 2,000 glaciers a year are projected to disappear worldwide under 1.5C of warming, roughly doubling under 4C [8]. That puts the 4C peak near 4,000 a year [1]. The study does not report how many glaciers exist today. That leaves the rate impossible to convert into a share. The shares are reported separately, and they are what the scenarios turn on: nearly half of today's glaciers remaining in 2100 at 1.5C against about 20 percent at 2.7C works out to 2.5 times as many [9][2]. The regional numbers are smaller and harder. About 110 glaciers may remain in the European Alps under 2.7C and as few as 20 under 4C [10], a drop of roughly 82 percent between the two [3].
"Global numbers such as glacier mass or area loss can feel very abstract. With this website, people can zoom into their own valley or mountain region and see what different levels of global warming could mean for the glaciers they know," Van Tricht said [4]. He said he hopes it "can also help local communities prepare for a future with fewer glaciers" [5]. Planning for a water utility or a hydropower operator runs on how much water comes down the valley in a given month. These projections give the year the ice runs out, not the monthly flow. "Every fraction of a degree matters," Van Tricht said [17].
What to watch
- Final end-of-summer 2026 Alpine measurements, still being collected, will set where this year ranks against the systematic record.
- Whether the explorer publishes the spread among the three glacier models for a given glacier, not only a single window.
- Whether the next Swiss glaciers declared extinct also fall inside their published projection windows.