Swiss Glaciers Shrink by a Fifth in Five Years as Record Heat Accelerates Alpine Melt

Switzerland's glaciers are disappearing at a pace that has alarmed the scientists who track them most closely. According to a report released Thursday by the Swiss Glacier Monitoring Network (GLAMOS) and the Swiss Commission for Cryosphere Observation of the Swiss Academy of Sciences (SCNAT), the country's glaciers shed 5.5 percent of their remaining ice volume during the hydrologic year that ended September 30, 2026. Taken together with losses recorded since 2021, that means roughly one-fifth of Switzerland's glacial ice has vanished in only five years — a scale of retreat that experts describe as unprecedented for the modern era.

The findings were compiled after a GLAMOS team fanned out across the country in September, visiting 23 glaciers to take end-of-summer measurements of both ice loss and snow accumulation. Those field observations form the backbone of the annual assessment, which has become one of the most closely watched indicators of how quickly Europe's alpine cryosphere is changing.

One of the most striking data points came from the Scex Rouge glacier in the western Swiss Alps. Matthias Huss, the head of GLAMOS and one of the report's authors, explained to Reuters that a measuring pole roughly four metres (13 feet) tall had been drilled into the ice in July to serve as a fixed reference point. When the team returned in early September, three metres (10 feet) of that pole had been exposed. In other words, the glacier had lost three metres of ice at an elevation of nearly 3,000 metres (9,843 feet) during August and September alone — a period that did not even include the heatwaves that gripped the region in June and July.

"This clearly indicates these conditions that we had this summer, they are just inconsistent with the survival of these small glaciers in the Alps," Huss told Reuters at the site.

The report estimates that the average thickness of individual Swiss glaciers fell by between 2.5 and four metres over the course of 2026. The losses were even more dramatic at glacier tongues — the narrow extensions where ice flows outward and downward — where thickness dropped by as much as 10 metres in some locations during the summer months. Such figures reflect not only the intensity of the summer heat but also the cumulative effect of repeated years of above-average melting.

Huss was unambiguous about the cause. "We can clearly attribute the massive ice loss to the warming, and thus anthropogenic climate change," he told Al Jazeera. "The summer has been the hottest on record in Switzerland. In addition, there was little snow in winter, and therefore the glaciers were poorly protected when the heat started." The absence of a protective snowpack in winter leaves dark ice exposed to the sun earlier in the season, accelerating melt once temperatures climb.

The report also documented the sheer volume of water released by the melting ice. Between July and September alone, Swiss glaciers lost approximately 2.2 trillion litres (581 billion gallons) of water. As the researchers noted, that is more than four times the annual drinking water consumption of all Swiss households combined — a statistic that underscores both the magnitude of the melt and the potential strain on future water supplies.

The consequences extend well beyond the glaciers themselves. Switzerland's economy leans heavily on its alpine landscape, with about 4 percent of the national workforce employed in the tourism sector. Winter sports and mountain tourism depend on snow and ice, and the visual transformation of the mountains is already under way. "This affects tourism and also how we perceive the mountains — they are no longer white but increasingly grey and black," Huss said. The image of a snow-capped Switzerland, long a pillar of the country's international identity, is being eroded along with the ice.

Glaciers also play a critical role in the country's energy and water systems. Meltwater feeds the reservoirs that supply hydropower lakes, which generate clean electricity, and it sustains some of the largest river systems in Europe. "We're not yet seeing the full consequences as glaciers are still around and they contribute water when we need it. But this potential is soon being lost," Huss warned.

Harry Zekollari, a glaciologist and associate research professor at the Department of Water and Climate at the Vrije Universiteit Brussel, echoed that concern. He emphasised that glaciers function as natural water suppliers precisely when demand is highest — during hot, dry summers. "With climate change, glaciers initially provide more water during summer as they rapidly melt. However, as glaciers become smaller, there is less ice to be melted, and as such the water supply in summer decreases," he told Al Jazeera. For the European Alps, he said, that peak in meltwater supply has already passed, meaning the region can expect progressively less glacial water in the years ahead.

Zekollari also pointed to broader risks. Glacier retreat can trigger natural hazards, and because most of the ice lost eventually reaches the oceans, the effects of glacial loss in Switzerland and elsewhere will be felt along coastlines around the world. The local and global dimensions of the problem are therefore intertwined.

As for solutions, the scientists are clear that the primary lever is temperature. Zekollari said the world must stabilise rising temperatures as quickly as possible if it hopes to preserve as much glacial ice as possible. Projections for the European Alps and Swiss glaciers indicate that rapid and sustained cuts to greenhouse gas emissions could still save a meaningful portion of the remaining ice — but every year of delay reduces what can be salvaged.

The GLAMOS report arrives amid a broader pattern of extreme summer conditions across Europe, which have fuelled concerns about water security, energy production, and the viability of mountain economies. For Switzerland, the latest figures are not an isolated anomaly but the continuation of a trend that has been building for decades. The measurement pole on the Scex Rouge glacier, exposed by three metres in a single late-summer stretch, offers a stark and tangible symbol of how quickly the country's frozen reservoirs are being depleted.