As Switzerland struggles to contain the shrinking of its glaciers, researchers are conducting an unusual experiment in the Alps to see whether one of its less valued natural resources can help: sheep’s wool. For years now, synthetic tarpaulins have been laid in summer over areas of ice and snow to reflect sunlight and reduce heat absorption as global warming melts away the ice sheets that have defined the high Alpine landscape for millennia. But those tarpaulins are typically made from plastic and can shed polluting microfibres. The “Keep It Wool” project, led by the environmental group Summit Foundation and the University of Lausanne, is instead using wool to slow the melting of the Tsanfleuron Glacier in western Switzerland. This summer’s record heat has melted snow on the glaciers weeks earlier than usual, leading almost inevitably to more of the ice loss blamed for exacerbating rockslides like the one that devastated the village of Blatten in 2025 - and triggered last week’s cataclysmic flash flood in the Himalayas. Project manager Timothee Steiner said the team wanted to explore a biodegradable alternative while finding a use for Swiss wool, 40-70 per cent of which is discarded each year. Four university master’s degree students had the idea and worked to put it to the test. In June, two prototype wool blankets made by the Swiss firm Fisolan were laid on 200 square metres (2,100 square feet) of the Tsanfleuron Glacier. Throughout the summer, researchers compared their performance with that of a conventional geotextile cover. Early results have exceeded expectations. Steiner said measurements taken every two weeks showed the wool covers limited melting as well as the synthetic ones. Fisolan’s Niklaus Saegesser said he was surprised by the material’s durability. “I thought it wouldn’t be stable enough.” Student Elliot Gaffiot said the team hadn’t been sure what to expect. “Now we have a result we can see and even touch. It worked incredibly well.” But the project’s backers stress that wool blankets are not a solution to global warming. Only about 0.02 per cent of Switzerland’s glacier surface is covered by protective sheets, and scientists say reducing greenhouse gas emissions - mostly produced by fossil fuels - remains the only meaningful long-term way to slow the loss of ice. Reporting by Cecile Mantovani and Denis Balibouse; Editing by Kevin Liffey
