Swiss glaciers have lost nearly 20% of ice in five years, monitoring network reports

Why This Matters

• The 20% loss in five years shows that Alpine glacier retreat is accelerating far beyond historical rates, affecting water supply, hydroelectric power and tourism across Europe.
• The temporary water bounty from melting in 2026 masked a longer-term threat: as glaciers shrink, the summer water flow they provide will diminish, potentially deepening seasonal droughts.
• The complete loss of smaller glaciers is a sign that total deglaciation of some Alpine valleys may come sooner than previously expected.

Background

Glaciers in the Alps have been retreating since the end of the Little Ice Age in the mid‑19th century, but the pace has sharply increased in recent decades due to human-caused climate change. Switzerland’s glaciers are among the most monitored in the world, with systematic measurements going back more than a century. The GLAMOS network, coordinated by ETH Zurich, provides annual assessments of ice volume change. The 2026 findings follow a record melt year in 2022 and continue a pattern of extreme loss driven by hotter summers and reduced snowfall.

Key Perspectives

Scientists at ETH Zurich and GLAMOS: The annual report documents a clear trend of accelerating ice loss driven by climate factors, with the 2026 season adding to a cumulative decline that is transforming Alpine landscapes and hydrology. The temporary water supply is a “double‑edged sword”, it helps in the short term but comes from a resource that is rapidly depleting. Water resource managers and downstream communities: The large meltwater release in summer 2026 eased shortfalls, but the prospect of a steadily shrinking glacier reservoir raises concerns about future water availability for drinking, irrigation and hydropower, especially during heatwaves. Climate policy proponents: The figures provide further evidence that greenhouse gas reductions are needed to slow ice loss; without them, Alpine glaciers could largely disappear within decades.

What to Watch

• The 2027 winter snowfall total: another low‑snow winter would set up another extreme melt season.
• The status of mid‑size glaciers such as the Rhône and Aletsch: if they continue to thin at current rates, their lower tongues may soon detach.
• Any policy response from the Swiss government or cantons regarding water management and adaptation to reduced glacier runoff.