Swiss Glaciers Lost 20% of Ice in 5 Years: Explained
🕐 9 min read | 🌍 Natural Wonders
🔒 Key Takeaways
- Swiss glaciers lost roughly 6% of their remaining volume in 2022 and a further 4% in 2023 — the two worst years in the Swiss measurement series.
- Switzerland's remaining ice stood at about 46.5 cubic kilometres in 2024, down from roughly 100 km³ in the 1930s.
- The Great Aletsch Glacier, the largest in the Alps at about 20 km long, has retreated more than 3 km since 1870 and is thinning by several metres a year at its tongue.
- On 28 May 2025 the collapse of the Birch Glacier buried roughly 90% of the village of Blatten in the Lötschental valley under rock, mud and ice.
- Under high-emission scenarios, modelling suggests more than 90% of Alpine glacier volume could be gone by 2100.
Imagine erasing one ice cube in every five from a freezer that took ten thousand years to fill. That is effectively what has happened to Switzerland glacier ice loss since 2020 — a retreat so fast that Swiss scientists have shut down monitoring on some glaciers because there is almost nothing left to measure. The causes stretch from dust storms in the Sahara to the simple physics of dirty snow.
The Numbers: What Switzerland Has Actually Lost
Switzerland is monitored more closely than almost any other glaciated country, thanks to GLAMOS — Glacier Monitoring Switzerland — whose length-change records reach back to the 1880s and whose mass-balance series began in 1914. Its verdict is blunt: the country's roughly 1,400 glaciers lost about 6% of their remaining volume in 2022, a further 4% in 2023, and kept shrinking through 2024 and 2025, with a 3% loss reported for the 2024/25 hydrological year. Stacked together, the losses of the early 2020s amount to close to a fifth of all the ice Switzerland held at the start of the decade. In absolute terms, the nation stored around 100 cubic kilometres of ice in the 1930s; by 2024 that had fallen to roughly 46.5 km³. To picture it, imagine a cube of ice one kilometre on every side — Switzerland has lost more than fifty of them. No comparable multi-year collapse appears anywhere in the Swiss measurement record.
Why 2022 Broke Every Record in the Swiss Series
Glacier health comes down to a simple ledger: snow gained in winter versus ice lost in summer. The winter of 2021–22 delivered an unusually thin snowpack across the Alps, with some stations reporting less than half their long-term average, stripping glaciers of their protective white blanket months early. Then came a summer of relentless European heatwaves, during which MeteoSwiss recorded the 0°C isotherm at 5,184 metres on 25 July 2022 — above the 4,808-metre summit of Mont Blanc. Bare glacier ice, which reflects only about 20–40% of incoming sunlight compared with up to 90% for fresh snow, lay exposed for the entire melt season. The outcome was a mass-balance catastrophe: monitored glaciers such as the Gries and Silvretta lost more than three metres of water-equivalent ice thickness in a single year, and ablation stakes drilled deep into the ice simply melted free and toppled over. GLAMOS described 2022 as the worst year since systematic measurements began.
🤔 Did You Know?
On 25 July 2022, MeteoSwiss measured the 0°C freezing level at 5,184 metres — higher than any summit in the Alps, meaning it was raining on the top of Mont Blanc.
Saharan Dust and the Albedo Feedback Loop
In mid-March 2022, strong southerly winds lifted plumes of Saharan dust across the Mediterranean and dumped them on the Alps, staining the snowpack a surreal orange from Valais to the Engadin. That dust layer was not cosmetic — it was thermodynamic. Clean snow reflects up to 90% of incoming solar radiation, while dust-darkened snow and bare ice may reflect as little as 20–30%, converting the rest into heat. This is the albedo feedback, and it is self-reinforcing: darker surfaces melt faster, which exposes older, dirtier ice and concentrates dust and black carbon at the surface, darkening the glacier further. Add cryoconite — dark granules of soot, mineral dust and living microbes that melt centimetre-scale holes into the ice surface — and the glacier becomes an efficient solar collector. Studies of Alpine and Caucasus dust events indicate deposition can shorten snow cover duration by several weeks and raise seasonal melt by tens of percent. The Sahara, in effect, reached across more than 2,000 kilometres to accelerate the dismantling of the Alps.
When Glaciers Collapse: The Blatten Disaster
Melting ice does not just vanish quietly — it destabilises entire mountainsides. Alpine peaks are partly held together by permafrost, and as that frozen cement thaws, rock faces lose cohesion and shed debris onto the glaciers below. On 28 May 2025, the Birch Glacier above the Lötschental valley in Valais gave way after an estimated several million cubic metres of rock from the Kleines Nesthorn loaded its surface, sending a torrent of ice, mud and boulders onto the valley floor. Roughly 90% of the village of Blatten was buried; its approximately 300 residents had been evacuated nine days earlier on the advice of geologists tracking the accelerating creep, which almost certainly prevented mass casualties. The debris dammed the River Lonza, creating a rising lake and a secondary flood hazard that forced further downstream evacuations. Blatten became the clearest warning yet that glacier retreat in Switzerland is an immediate civil-protection problem, not a slow-motion postcard one.
Europe's Water Tower Is Running Dry
The Alps are nicknamed the water tower of Europe for good reason: they feed the Rhine, the Rhône, the Po and tributaries of the Danube, supplying water far beyond Switzerland's borders. Glaciers act as a natural savings account, storing winter precipitation as ice and releasing meltwater precisely when summers are hottest and driest. Accelerated melting is currently producing a temporary surplus of runoff — but hydrologists call this 'peak water', and modelling indicates many Swiss catchments passed theirs between the 1980s and the 2010s. After peak water, late-summer flows decline permanently as the ice reservoir shrinks. That matters acutely for Switzerland, where hydropower supplies around 57% of national electricity, and for the Rhine, where the Kaub gauge fell to roughly 32 centimetres in August 2022 and halted loaded barge traffic. Irrigation, power-plant cooling and cold-water river ecosystems all sit downstream of ice that will not be replaced.
Which Swiss Glaciers Are Already Gone?
Some names have already been struck from the Swiss register. The Pizol Glacier in St. Gallen shrank so drastically — losing on the order of 80–90% of its volume since 2006 — that scientists and some 250 mourners held a public 'funeral' for it in September 2019 before it was removed from the monitoring network. Measurements on the Vadret dal Corvatsch in the Engadin were abandoned in 2022 because the glacier had effectively disintegrated, and the St. Annafirn in Uri was declared dead the same year. GLAMOS reports that glaciers thinner than about 25 metres are now capable of melting out entirely within a single hot decade. Even the giants are shrinking: the Great Aletsch Glacier, the largest in the Alps at roughly 20 kilometres long and holding on the order of 10 billion tonnes of ice, has retreated more than 3 kilometres since 1870 and is thinning rapidly at its tongue. On the Rhône Glacier near Gletsch, operators now spread white fleece blankets over several hectares of ice each summer to slow melting of the ice-grotto tourist attraction.
Can Anything Still Be Saved?
Glaciers respond to climate with a lag of decades, which means a substantial fraction of future Alpine melt is already committed by past emissions. Modelling published by ETH Zurich and partner institutions suggests that even if global warming were held to 1.5°C, roughly half of Alpine glacier volume would still disappear this century. Under high-emission trajectories, more than 90% could be gone before 2100, leaving patchy ice only on the highest north-facing slopes of massifs such as Monte Rosa (4,634 m) and Mont Blanc (4,808 m). Local interventions — geotextile covers, artificial snow production, slush-pumping trials in the Engadin — can measurably protect patches of a few hectares, with covered areas losing roughly 50–70% less ice, but they are economically and physically unworkable across a 20-kilometre glacier. The only lever that operates at the scale of a mountain range is emissions reduction. Every tenth of a degree of warming avoided translates directly into cubic kilometres of ice that survive into the next century.
Final Thoughts
Switzerland's glaciers are not merely shrinking — they are being dismantled within a single human lifetime, and in May 2025 the rubble landed on a village. Read GLAMOS's annual glacier report, published each autumn and freely available at glamos.ch, to track the ledger yourself, then compare its repeat photographs of the Rhône Glacier from 1900 and today. The next chapter is thawing permafrost, the frozen cement now loosening whole Alpine faces.
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Frequently Asked Questions
How much ice have Swiss glaciers lost?
Swiss glaciers lost about 6% of their remaining volume in 2022 and a further 4% in 2023, with continued losses in 2024 and 2025 — close to a fifth of all their ice in roughly five years. Total Swiss glacier volume has fallen from around 100 km³ in the 1930s to approximately 46.5 km³ in 2024.
Will Swiss glaciers disappear completely?
Most of them will. Modelling suggests that even with warming limited to 1.5°C, around half of Alpine glacier volume will vanish this century, while high-emission scenarios remove more than 90% by 2100. Only small remnants on the highest, shaded slopes of massifs like Monte Rosa are expected to survive.
What happened to the village of Blatten in Switzerland?
On 28 May 2025 the Birch Glacier above Blatten in the Lötschental valley collapsed after rockfall from a thawing permafrost slope overloaded it, burying roughly 90% of the village in ice, mud and debris. Its roughly 300 residents had been evacuated nine days earlier on geologists' advice, which prevented mass casualties.
Why did Saharan dust make Swiss glaciers melt faster?
Dust deposited on the snowpack in March 2022 sharply reduced its albedo, so the surface absorbed far more sunlight instead of reflecting it. The darkened snow melted away early, exposing bare ice for the whole summer and amplifying what became the worst melt season in the Swiss record.
How fast is the Aletsch Glacier retreating?
The Great Aletsch Glacier has retreated more than 3 kilometres since 1870 and continues to lose ground at its tongue, while thinning by several metres in bad years. At about 20 kilometres long it remains the largest glacier in the Alps, but projections show it shrinking dramatically by 2100.
📚 Further Reading & Research Sources
The following journals and institutions publish peer-reviewed research on the topics covered in this article:
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Aletsch Glacier, Valais, Switzerland — photograph via Wikimedia Commons (CC BY-SA)
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