Wool blankets to save glaciers: Switzerland is testing a curious technique to slow melting
The summer of 2026 had a major impact on Swiss glaciers, and to reduce ice loss and preserve skiing, even sheep’s wool blankets are being tested.
The summer of 2026 was dramatic for Alpine glaciers. Even high-altitude glaciers suffered significantly, as the freezing level frequently rose above 4,500 meters and occasionally even reached 5,000 meters. Winter snow disappeared prematurely due to the early heat that began in late May, and repeated heat waves made matters worse.
The impact has been severe on the landscape, water resources, hydrogeological and snow-and-ice-related hazards, as well as sports tourism. The summer skiing industry, in particular, has been trying for years to mitigate the impacts of climate change with the controversial technique of covering parts of glaciers with geotextile sheets. Now, news from Switzerland suggests that coverings made from a natural material are being tested: wool.
Covering glaciers: what does it involve?
For several years, some glaciers—or, more precisely, small portions of areas used for alpine skiing—have been covered with large special sheets made of synthetic materials known as "geotextiles". These are spread over the ice during the summer season in areas not used for summer skiing, with the aim of preserving them for fall openings or the following season.
The first applications date back to the beginning of the 21st century. In Italy, the best-known example is the Presena Glacier, where summer skiing was once practiced and which has been seasonally covered since 2008. The technique has since spread to other Italian glaciers, as well as glaciers in France, Switzerland and Austria.
The impact of geotextile coverings
However, geotextile coverings have an environmental impact and present several problems and limitations in terms of effectiveness, costs, pollution and landscape alteration. They also do not actually save the glacier, but only preserve small portions for sports and tourism purposes.
We have previously written about a letter signed by 44 climate and glacier experts, in collaboration with organizations that monitor Italian glaciers, in which they explain why covering glaciers is not a solution.
The coverings release large amounts of fibers and microplastics, which accumulate on the glacier, flow into meltwater, end up in streams and rivers, and are also dispersed into the atmosphere.
The new approach: products made from natural wool
Aware of the environmental impact of geotextile coverings, a group of students from the University of Lausanne and the environmental organization Summit Foundation have developed a more sustainable alternative. Through the "Keep It Wool" project, they have created coverings made from sheep's wool to protect the ice.
The benefit could be twofold, since a large percentage of wool today becomes waste, including material that ultimately ends up in landfills.
The first wool glacier blankets were manufactured by the company Fisolan, and in June 2026 they were spread across 200 square meters of the Tsanfleuron Glacier.
Scientists are analyzing the initial results, which show that the wool sheets are similarly effective to synthetic geotextiles.
How much glacier ice do the coverings actually save?
According to scientists, this measure is a viable and sustainable alternative for slowing glacier melt, but it does not truly counteract the broader impact of global warming.
More broadly, the technique of installing coverings, whether geotextile or wool, is not actually used to save glaciers, but rather to limit ice loss in the small areas designated for winter sports. The covered surface is, in fact, only a very small portion of the glacier; the Tsanfleuron Glacier, where the experiment is taking place, covers approximately 3.8 km². The portion covered with wool therefore represents just 0.007% of its total surface area.
That leaves the real problem: climate change.
The solution to glacier retreat does not lie in protective coverings, but in the drastic reduction of human-caused greenhouse gas emissions, primarily those resulting from the use of fossil fuels.
Article reference
Covering glaciers with blankets to keep them from melting: Switzerland's effort to protect them from climate change