A fifth of Swiss Alpine ice has vanished in five years

Matthias Huss, director of the Swiss Glacier Monitoring Network (GLAMOS), highlights the retreat of the Rhône Glacier in the Swiss Alps: its thickness decreased by four metres between mid-June and mid-July 2026. Keystone / Jean-Christophe Bott

Swiss glaciers faced another "catastrophic year" in 2026, according to the Swiss Academy of Sciences. Summer heatwaves and low winter snowfall led to the disappearance of dozens of Alpine glaciers.

In 2026, Swiss glaciers lost 5.5% of their total volume, according to the latest assessmentExternal link by the Glacier monitoring in Switzerland (GLAMOS) and the Swiss Academy of Sciences (SCNAT). In some areas, average ice thickness decreased by between 2.5 and 4 metres, continuing a pattern of melting and recession that experts say will have devastating effects.

“It’s staggering to see the enormous amount of ice that has melted. But what is even more striking is that events of this magnitude are now recurring year after year,” Matthias Huss, director of GLAMOS, told Swissinfo. “What used to be extreme events, by definition rare and very intense, now occur almost every summer.”

Over the past five years alone, the volume of ice in the Swiss Alps has fallen by almost 20%.

“These exceptional losses show that the climate is warming too rapidly for glaciers to adapt,” Huss adds.

The giant of the Alps loses 13 metres of ice

The year 2026 ranks second only to 2022 for the greatest glacier losses since measurements began. Although temperatures were higher this year, melting was slightly less severe than four years ago due to more abundant snow cover on many glaciers.

In addition, less Saharan dust settled on the snow in 2026. As a result, more sunlight was reflected back into the atmosphere.

There were, however, notable exceptions. Some glaciers, including the Rhône Glacier and the Aletsch Glacier (the largest glacier in the Alps) experienced the most intense melting ever recorded in 2026. At the lowest monitoring point on the Aletsch Glacier tongue, ice thickness decreased by 13 metres.

The steps leading up to the Concordia hut, above the Aletsch Glacier, provide access to the glacier. When it was built, over 100 years ago, the ice was almost at the same level as the hut. Matthias Huss

Too little snow to shield glaciers from the heat

Exceptionally high temperatures and repeated heatwaves between May and September were not the only reason for this year’s major glacier losses in Switzerland. Winter snowfall was well below the long-term average at all elevations, meaning the snow layer that normally protects glaciers from summer heat was simply too thin.

One indicator of these unfavourable conditions is the so-called “glacier loss day”, which marks the date when glaciers have exhausted the snow and ice reserves accumulated during winter and begin losing mass. This year, that threshold was reached as early as June 29. Apart from 2022, when it fell on June 26, that date had always been declared in July, August or even September since 2000.

Another significant indicator is the 0°C isotherm, the altitude at which air temperature reaches freezing point. Between May and September, the 0°C level remained above 4,000 metres for 76 days. “This is more than double the average and a record,” SCNAT wrote, adding that under such conditions, “Alpine glaciers have no chance of surviving in the long term”.

Around 30 Swiss glaciers vanished this summer

Over the past 50 years, Switzerland has lost more than 1,000 glaciersExternal link, roughly 40% of the national total, as a result of human-induced climate change. Between 2016 and 2023, 160 glaciers disappeared, and according to Huss, this summer may have marked the end of at least 30 additional small glaciers.

The Plattalva Glacier in canton Glarus was declared extinct after disappearing completely in September. It was no ordinary glacier: in the 1950s, it hosted what was probably the world’s most detailed glacier monitoring programme, Huss notes. Measurements of seasonal glacier mass changes carried out between 1947 and 1985 constitute an exceptional data record from a period when glacier observations were still very limited.

Like switching off the lights: The ultimate disappearance of Plattalva #GlacierExternal link in the extreme summer of 2026.

Another glacier has gone. It may seem unremarkable but in the 1950s it hosted the maybe most detailed glacier monitoring programme worldwide@glamos_chExternal link @VAW_glaciologyExternal link pic.twitter.com/V9iwJwXV1tExternal link

— Matthias Huss (@matthias_huss) September 10, 2026External link

Without a drastic reduction in greenhouse gas emissions, half of all Alpine glaciers could disappear within the next 20 years, according to a studyExternal link published in 2025. By the end of the century, only the largest glaciers, such as the Aletsch and Rhône glaciers, may survive.

Less water from glaciers to cope with drought

Glacier melt currently releases vast quantities of water into lowland regions and major European rivers, including the Rhine, Rhône and Danube. For now, this helps to partially alleviate water shortages during summer.

Between July and September, glaciers lost roughly 2,200 billion litres of water, according to SCNAT. This volume is equivalent to more than four times the annual drinking-water consumption of all households in Switzerland. Without this contribution, river levels would have been even lower this summer.

However, this glacier-fed water supply is expected to decline. Alpine glaciers have already reached, or will soon reach, “peak water”, the point at which meltwater runoff begins to decrease progressively.

In the future, glacier melt will no longer be sufficient to offset water deficits caused by more frequent and prolonged droughts. This will mean less water in Alpine valleys and European rivers, with implications for navigation, agriculture, ecosystems, drinking-water resources and energy production.

“The problem isn’t just that there will be less water,” saysExternal link Giovanni De Cesare, operational head of the Hydraulic Constructions Platform at the Swiss Federal Institute of Technology Lausanne (EPFL). “Today, glaciers melt all summer long, providing a steady stream of runoff. When they’re gone, we’ll have to rely directly on precipitation – rain and snowfall – which is much less predictable.”

Long regarded as a symbol of the Swiss Alps, glaciers are disappearing at an unprecedented pace. Their rapid decline is not only transforming the Alpine landscape, but also one of Europe’s most important freshwater reserves.

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Edited by Gabe Bullard/ds