A stunning new forecast shows when thousands of glaciers will vanish

• A major new international study led by ETH Zurich has, for the first time, estimated how many of the world's glaciers are expected to survive through the end of this century and how long each one is likely to last.
• The findings show a dramatic contrast between warming scenarios. If global temperatures rise to +4.0 °C, only about 18,000 glaciers would remain worldwide. Limiting warming to +1.5 °C could preserve roughly 100,000 glaciers.
• The researchers also introduced the concept of "Peak Glacier Extinction," which marks the year when glacier losses reach their highest level. At +1.5 °C, this peak is projected to occur around 2041 with about 2,000 glaciers disappearing in a single year. Under +4 °C warming, the peak shifts to around 2055 and annual losses rise to roughly 4,000 glaciers.

Glaciers across the planet are shrinking at an accelerating pace. In some parts of the world, they are expected to disappear entirely. When scientists focus on the number of individual glaciers that are vanishing, rather than total ice volume, they find that the Alps could reach their highest rate of glacier loss between 2033 and 2041. How severe this period becomes depends on how much global temperatures rise. During this window, more glaciers could disappear than at any other time on record. On a global scale, the peak in glacier losses is expected roughly a decade later, with annual losses rising from about 2,000 to as many as 4,000 glaciers.

Alpine glaciers face near total collapse

The outlook for the Alps is especially severe. If current climate policies lead to a global temperature increase of +2.7 °C, projections suggest that by 2100 only around 110 glaciers would remain in Central Europe. This would represent just 3 per cent of today's total. Under a +4 °C warming scenario, that number drops further to about 20 glaciers. Even glaciers of moderate size, including the Rhône Glacier, would be reduced to small patches of ice or vanish altogether. In the same scenario, the vast Aletsch Glacier would break apart into several smaller sections. These changes extend a pattern already documented by ETH Zurich researchers, and there is no indication that it is slowing. Their work shows that between 1973 and 2016, more than 1,000 glaciers disappeared in Switzerland alone (cf. Annals of Glaciology).

Counting glaciers rather than ice volume

An international research team led by ETH Zurich, the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), and the Vrije Universiteit Brussel used these findings as part of a comprehensive new study. For the first time, the researchers calculated how many glaciers around the world disappear each year, how many are likely to survive through the end of the century, and how long individual glaciers are expected to persist. "For the first time, we've put years on when every single glacier on Earth will disappear," says Lander Van Tricht, lead author of the study published on December 15, 2025, in Nature Climate Change.

Previous studies largely examined glacier change by measuring total ice mass or surface area. In contrast, the ETH Zurich-led team focused on the number of glaciers themselves, their geographic distribution, and the timing of their disappearance. This approach reveals that regions dominated by small glaciers at lower elevations or closer to the equator face the greatest risk. These vulnerable areas include the Alps, the Caucasus, the Rocky Mountains, and parts of the Andes and African mountain ranges located at low latitudes.

"In these regions, more than half of all glaciers are expected to vanish within the next ten to twenty years," says Van Tricht, who works at ETH Zurich's Chair of Glaciology and the WSL.

How many glaciers could still survive?

The speed at which glaciers retreat is closely tied to how much the planet warms. To explore this relationship, the researchers ran simulations using three advanced global glacier models across several climate scenarios. For the Alps, their results show that limiting warming to +1.5 °C would allow about 12 per cent of glaciers to remain by 2100, or roughly 430 out of about 3,000 glaciers present in 2025. At +2.0 °C, the number falls to around 8 per cent, or about 270 glaciers. At +4 °C, survival drops to just 1 per cent, which corresponds to about 20 glaciers.

Similar patterns appear in other mountain regions. In the Rocky Mountains, about 4,400 glaciers would persist under a +1.5 °C scenario, representing roughly 25 per cent of today's estimated 18,000 glaciers. At +4 °C, only about 101 would remain, amounting to a 99 per cent loss. In both the Andes and Central Asia, approximately 43 per cent of glaciers would survive at +1.5 °C. Under +4 °C of warming, the situation changes sharply. The Andes would retain only around 950 glaciers, a 94 per cent reduction, while Central Asia would be left with roughly 2,500 glaciers, a 96 percent decline. Globally, a +4.0 °C world would be home to about 18,000 glaciers, compared with around 100,000 if warming were limited to +1.5°C.

The analysis also shows that glacier numbers are falling everywhere. No region is projected to escape this trend. Even in the Karakoram region of Central Asia, where some glaciers briefly advanced after the turn of the millennium, long-term projections show continued glacier loss.

Peak Glacier Extinction explains the turning point

The researchers introduce a new concept called "Peak Glacier Extinction." This term describes the moment when the number of glaciers disappearing in a single year reaches its highest level. After that point, annual losses decline because many of the smaller glaciers have already vanished. From a policy perspective, this distinction is important. Glacier ice continues to shrink even after the number of disappearing glaciers begins to fall.

The timing of this peak varies depending on warming levels. Under a +1.5 °C increase in global temperature, consistent with the Paris Agreement, Peak Glacier Extinction is expected around 2041, when about 2,000 glaciers disappear in one year. With +4 °C of warming, the peak shifts to around 2055 and the annual number of lost glaciers rises to about 4,000. Although it may seem counterintuitive that the peak arrives later under stronger warming, the explanation lies in the behavior of larger glaciers. In warmer conditions, not only do small glaciers vanish, but large glaciers also eventually disappear. Accounting for the complete loss of even the biggest glaciers is one of the key strengths of this approach.

The ETH Zurich team found that at +4 °C, the number of glaciers disappearing at the peak is roughly double that seen at +1.5 °C. Under the 1.5-degree scenario, about half of today's glaciers are expected to survive. At +2.7 °C, only about one-fifth remain, and at +4 °C, survival drops to around one-tenth. Even small differences in temperature matter. "The results underline how urgently ambitious climate action is needed," says Daniel Farinotti, co-author of the study and Professor of Glaciology at ETH Zurich.

Why glacier loss matters beyond climate science

The retreat of glaciers has consequences that extend well beyond climate metrics. This new way of measuring glacier loss offers valuable insights for politics, economies, and cultural life. Earlier research focused on glacier mass and volume, which is essential for estimating sea-level rise and managing water resources. "The melting of a small glacier hardly contributes to rising seas. But when a glacier disappears completely, it can severely impact tourism in a valley," says Van Tricht.

By identifying when and where glaciers are likely to vanish, the study also provides practical guidance. Policymakers, local communities, the tourism industry, and those responsible for managing natural hazards can use this information to prepare for a future with less ice and more uncertain water supplies.

In parallel with this scientific work, ETH Zurich researchers are contributing to projects such as the Global Glacier Casualty List. This initiative documents the names and histories of glaciers that have already disappeared, including the Birch and Pizol glaciers. "Every glacier is tied to a place, a story and people who feel its loss," says Van Tricht. "That's why we work both to protect the glaciers that remain and to keep alive the memory of those that are gone."