Swiss Glaciers Lose 5.5% of Ice in One Year as Scientists Warn of ‘Disastrous’ Melt

Switzerland’s glaciers lost an estimated 5.5% of their remaining ice volume over the past 12 months, according to new figures that scientists have described as “disastrous” and far beyond what was once considered extreme.

The data, published by Glacier Monitoring Switzerland (GLAMOS), reveals that the Alpine nation’s glaciers have now endured a near-record year of shrinkage, driven largely by intense summer heatwaves that pushed temperatures well above seasonal norms.

Dr Matthias Huss, the director of GLAMOS, which produced the report, said the scale of the loss was difficult to overstate. “It’s really just disastrous,” he said, adding that a decade ago he would not have believed such rapid melting was possible.

Until recently, glaciologists in the Alps regarded a 2% loss of ice in a single year as an “extreme” event. The 5.5% figure for 2026 is nearly three times that benchmark, underscoring how quickly the cryosphere is now responding to a warming climate.

The report’s central finding is not simply that Swiss glaciers are shrinking — a trend that has been well documented for decades and is driven primarily by fossil fuel emissions — but the sheer velocity of the melt.

Scientists warn that the consequences extend far beyond the mountains themselves. Glaciers act as natural reservoirs, storing water in frozen form through the winter and releasing it gradually during hot, dry periods. That meltwater supports farming irrigation, hydropower generation and even river navigation across Europe.

Glacier Monitoring Switzerland estimates that Swiss glaciers released roughly 2.2 trillion litres of meltwater between July and September this year. While that outflow helped ease water shortages during the summer’s heatwaves, it came at a heavy cost: the frozen supply that would ordinarily be available in future years has been rapidly depleted.

Huss explained that the water now flowing off the mountains is, in effect, ancient savings. “Every drop of water that runs off during these heatwaves is kind of old water that’s been stocked in the glacier ice centuries or decades ago,” he said. “It’s helping us now, but it’s unsustainable, so we won’t have it at our disposal in the next heatwave.”

The summer of 2026 brought multiple factors together to produce the exceptional melt. Swiss glaciers entered the season in a weakened state, having received less snow than usual during a mild winter. Much of that thin snowpack then vanished rapidly during early and intense heatwaves in May and June.

That early loss exposed bare glacier ice, which is darker and less reflective than fresh snow. As a result, the ice absorbed more of the sun’s energy, leaving glaciers even more vulnerable to subsequent heatwaves later in the summer. The process amounts to a feedback loop that accelerates melting once snow cover is gone.

The strain was not confined to lower elevations. Researchers found that even at measurement sites as high as 3,500 metres above sea level — where temperatures are lowest and glaciers are typically covered by snow — no snow remained at the end of summer.

“At some glaciers we’ve seen four metres of ice loss at the highest point, where they should be covered by several metres of winter snow at this time of the year,” Huss said. Snow functions as glacier food; under stable conditions, some of it compacts into ice over time. But if no snow survives the summer, it cannot replenish the ice lost at lower, warmer elevations. Deprived of that input, a glacier starves, shrinks and eventually disappears.

Dr Fabien Maussion, a glaciologist at the University of Bristol who was not involved in the Swiss report, said the findings were distressing but not surprising from a scientific standpoint. “Ten years ago, I wouldn’t have thought that it’s possible to lose glaciers so quickly,” he said. “What’s happened over the summer now is extremely distressing… but at the same time it was to be expected from a climate scientist’s perspective.”

Maussion offered a simple analogy for the public. “Glaciers are complex because they gain mass at the top and they flow downstream, so there is a lot of physics,” he said. “But in its simplest form, what we see right now is that we took an ice cube out of the fridge and it’s just melting in front of our eyes.”

The implications of such rapid ice loss are already being felt. The River Rhine reached record lows in places this summer, disrupting shipping routes and driving up transport costs. As glaciers shrink, their ability to buffer against drought weakens, raising the prospect of more acute water shortages in the decades ahead.

There are also growing concerns about mountain stability. The loss of glacier ice can destabilise slopes and increase the risk of landslides, which in extreme cases can trigger flash flooding. In August, a large area of bedrock and glacier ice collapsed in Nepal, causing a disaster in which multiple factors were involved. Scientists say long-term glacier thinning and the thawing of frozen ground likely raised the risks there.

Some Alpine glaciers have already vanished entirely. Plattalva, in eastern Switzerland, is among those that have disappeared. Scientists say the climate is now too warm for many glaciers in the Alps to survive, even if emissions were to fall sharply starting today.

Yet researchers stress that the picture is not uniform across the planet. Sharp cuts to carbon emissions could still save much of the world’s glacier ice, particularly in the Himalayas and the polar regions, where the majority of Earth’s frozen water is stored.

“There we still can make a big difference with protecting the climate,” Huss said. “If these ice masses can be saved or stabilised, we can limit the rise of global sea levels… which could affect billions of people living along the coast.”

The Swiss report adds to a growing body of evidence that the Alps are warming at roughly twice the global average rate. That geographic reality means the region’s glaciers are acting as an early warning system for the wider climate crisis, offering a preview of what other mountain ranges may face in the coming decades.

For now, the data from 2026 stands as one of the starkest single-year losses on record. The question scientists are asking is not whether Swiss glaciers will continue to retreat, but how much ice can still be preserved — and how quickly the world can reduce the emissions that are driving the melt.