Switzerland's glaciers shrank by 20% in just 5 years, the second-worst record in their history

Switzerland retains approximately 1,300 glaciers in the Alps after recording a continuous reduction in their total surface area since 1973 (Wikimedia Commons)Switzerland retains nearly 1,300 glaciers, distributed across the Alps. The most recent complete national inventory, compiled with data covering the 2013-2018 period, identified 1,400 glacial formations with a total surface area of 961 square kilometers. That extent already reflected a reduction from the 1,311 square kilometers recorded in 1973. The most recent studies show that the retreat has accelerated. The Glacier Monitoring in Switzerland (GLAMOS) network calculated that Switzerland's ice masses lost 5.5% of their volume in the 2025/26 hydrological year, the second worst balance in the historical series. The cumulative loss since 2021 reaches almost 20%, following a winter with little snow and several months of drought and high temperatures. The melting also led to the disappearance of small glaciers and the thinning of the large Alpine ice masses. The GLAMOS monitoring network confirmed that Switzerland's ice masses lost nearly 20% of their accumulated volume between 2021 and 2026 (EFE/EPA/JEAN-CHRISTOPHE BOTT)In just five years, Switzerland's glaciers lost nearly 20% of their ice volume, a drop that accounts for part of the accumulated reduction over recent decades and exposes the impact of winters with little snow and increasingly hot summers in the Alps. The latest annual measurement by the Glacier Monitoring in Switzerland (GLAMOS) network and the Swiss Commission for Cryosphere Observation of the Swiss Academy of Natural Sciences indicated that, during the 2025/26 hydrological year, the country's glacier volume fell by 5.5%. It was the second worst result since the series began, surpassed only by that of 2022. The glacial retreat caused the complete disappearance of small formations such as the Bella Tola in the canton of Valais (REUTERS/Denis Balibouse)The study took data in September from 23 reference glaciers and extrapolated it to the whole of the roughly 1,300 ice masses that remain in the country. Scientists compare variations in thickness, snow accumulation and ice loss to estimate the annual change in volume. The balance for this period was -2.9 meters of water equivalent, a measure that expresses how much water the lost ice represents. The season began with a winter that ranked among the ten least snowy since measurements began. That cover is decisive because it acts as a protective layer against solar radiation. When it disappears too early, the dark ice is exposed, absorbs more heat and accelerates melting. A winter with little snow leaves the dark ice exposed, which accelerates the absorption of solar radiation in the Alps (REUTERS/Denis Balibouse)Between May and September, Switzerland experienced dry conditions and at least one heat wave each month, according to the report released by GLAMOS and the Swiss Academy of Natural Sciences. The zero-degree line exceeded 4,000 meters for 76 days, a record that allowed melting to reach high mountain sectors that usually retain snow even at the end of summer. The result was an average reduction in thickness of between 2.5 and 4 meters. In some glacier tongues, the lowest and most exposed zones, the loss reached about 10 meters. The observations also recorded the disappearance of small glaciers, including the Bella Tola, in the canton of Valais, and the Griessfirn or Plattalvafirn, in Glarus. The melting released about 2.2 billion cubic meters of water between July and September, a volume equivalent to more than four times the annual drinking water consumption of Swiss households. That discharge helped ease water scarcity during the summer, although it implies a loss of the ice reserves that feed rivers during warm and dry periods. The melting of the ice released 2.2 billion cubic meters of water between the months of July and September (AP Foto/Matthias Schrader)As Matthias Huss, director of GLAMOS, explained to the BBC, the water that flows during heat waves comes from ice accumulated over decades or centuries. As the glaciers shrink, their summer contribution will diminish, with effects on irrigation, hydroelectric generation and river navigation. This summer, the Rhine reached historic lows in some stretches, affecting transport along that route. The retreat also alters the stability of the mountainous terrain. The loss of ice and the thawing of permafrost, the soil that remains frozen at altitude, can favor rockfalls, landslides and sudden floods in the Alpine valleys. Climate projections indicate that the deterioration will continue even if temperatures were to stop rising immediately, due to the delayed response of the ice masses. A report by the Swiss Federal Office for the Environment calculated that the country's glaciers would lose between 59% and 93% of their volume from 2018 to 2100, depending on the future evolution of greenhouse gas emissions. The Federal Office for the Environment projects that the glaciers will lose between 59% and 93% of their volume by the year 2100 (AP Photo/Matthias Schrader, File)In a low-emissions scenario, about 41% of the reference ice would remain. With high warming, the loss could reach 94%, leaving isolated remnants in the highest areas of the Alps. The official report on the future of Swiss hydrology, published by the University of Geneva, warns that the surviving ice masses would be concentrated mainly above 3,000 meters of altitude. GLAMOS estimates that Swiss glacier volume has already shrunk by almost 40% since the year 2000. The evolution of the coming years will depend on the amount of snow that accumulates in winter, the intensity of the summers and, above all, the trajectory of global emissions.