Swiss Glaciers Lose Nearly 20% of Their Ice in Five Years, Report Finds

Switzerland's glaciers are shrinking at a pace that has erased entire ice bodies, according to the annual report of the Swiss Academy of Sciences (SCNAT). The report says the country has lost nearly 20% of its total glacier ice volume in just five years, and that several of its best-known glaciers had their worst melting on record in 2026.

The Rhône, Aletsch and Clariden glaciers all experienced their most severe melting since records began. Some smaller glaciers fared even worse. Bella Tola in the canton of Valais and Griessfirn in the canton of Glarus disappeared entirely and, in the report's words, have now vanished permanently. The summary accompanying the report states that Swiss glaciers lost more than 5% of their ice volume in 2026 alone.

The findings draw on long-term observations from the Glacier Monitoring Network, known as GLAMOS. The monitoring program is based at ETH Zurich and the universities of Fribourg and Zurich. The source material does not detail the specific measurement techniques used, so this article does not describe them.

According to the report, two factors combined to drive the losses: little snow and long stretches of heat. The winter of 2025 to 2026 ranked among Switzerland's ten least snowy winters since records began. Snow acts as a protective layer for glaciers, so a thin snowpack left the ice more exposed once warm weather arrived.

Conditions then worsened. Between May and September 2026, persistent heat and dry weather sped up ice loss, even at the highest elevations. The researchers note that the elevation at which temperatures reached freezing climbed above 4,000 meters on 76 days. That is more than twice the usual number of days and set a new Swiss record. By September, snow had vanished even at 3,500 meters, uncovering glacier ice that would normally stay buried beneath snow.

The melting had a short-term upside. Between July and September, Switzerland's glaciers released roughly 2.2 trillion liters of water. That is more than four times the amount of drinking water Swiss households consume in an entire year, and it temporarily helped ease summer water shortages.

But the report cautions that this extra water comes from a resource that is being used up. Because the glaciers are shrinking irreversibly, the meltwater they can supply will decline over time. That would reduce a source that currently helps offset shortages during the warmer months. In other words, the boost to water supplies is a sign of loss rather than abundance.

The source material has some limits. It is a summary of an annual report rather than a peer-reviewed journal paper, and no journal reference is listed. It also does not provide year-by-year figures behind the five-year total, nor a breakdown of how much each glacier lost. It does not offer projections for how much ice may remain in coming years or how water managers might respond to declining meltwater.

Even so, the picture the report paints is stark. A single hot, snow-poor year produced record losses at famous glaciers and permanently erased smaller ones, while pushing the freezing level to heights rarely seen. The monitoring network's continued observations will show whether 2026 stands as an outlier or part of a lasting pattern, but the loss already recorded cannot be undone.