Picture standing on bare rock where, within a single human generation, there sat hundreds of metres of solid ice. That is what Matthias Huss, a glaciologist at ETH Zürich, experienced last week on a visit to a small Alpine glacier. "I visited one last week and it's so impressive to stand in this moonlike landscape where there was a big layer of ice – an extensive glacier – just a few years ago," he said. Now, scattered blocks of ancient ice lie melting on hot stone, like ice cubes forgotten on a summer pavement.

The numbers behind that eerie scene are startling. According to an annual report from the Swiss Glacier Monitoring Network and the Swiss Commission for Cryosphere Observation, Swiss glaciers shrank by 5.5% in just the first eight months of 2026, following a winter that brought little snow and a summer of punishing heat. That brings the total volume lost since 2021 to 19.

4% — almost a fifth of the country's ice, gone in five years. Individual glaciers thinned by between 2.5 and 4 metres this year alone. What makes this retreat especially unsettling is how it is happening.

Rather than simply melting from the surface downward, many glaciers are now collapsing from within. Meltwater carves tunnels and caverns beneath the ice, and their roofs eventually give way. "You have huge holes like cheese in the middle of the ice that have collapsing roofs," Huss explained, describing a process that tears glaciers apart far faster than gradual shrinkage ever could.