Wool Blankets on Swiss Glacier Cut Melt by Half, Study Finds 2026

In a groundbreaking experiment, wool blankets on a Swiss glacier have been shown to reduce ice melt by approximately half, offering a natural alternative to synthetic covers used for years. Four master's students from the University of Lausanne and the Summit Foundation launched the Keep It Wool project in 2025, and their initial results are turning heads in the climate adaptation community.

The idea is simple yet audacious: cover part of a glacier with sheep's wool and let it sit through the summer. In June 2026, the team installed two 100-square-meter wool prototypes on the Tsanfleuron glacier in the Swiss Alps, alongside a conventional geotextile cover for comparison. By September, measurements suggested the wool performed nearly as well as the synthetic covers, which typically reduce localized melt by 50% to 70%.

Why Cover a Glacier with Wool?

Glaciers worldwide are retreating at alarming rates due to climate change. In the Alps, rising temperatures have caused significant ice loss, threatening water supplies, tourism, and local ecosystems. While reducing global emissions is the ultimate solution, local interventions can help preserve vulnerable ice masses.

Synthetic geotextile covers have been used for years to protect ski slopes and glacier areas, but they come with drawbacks: they're made from fossil fuels, can be expensive, and are not biodegradable. Wool, on the other hand, is a natural, renewable resource. If it proves effective, it could provide a more sustainable and cost-effective way to slow glacier melt.

• Natural insulation: Wool's structure traps air, providing excellent thermal insulation.
• Renewable and biodegradable: Unlike synthetic covers, wool comes from sheep and breaks down naturally.
• Locally sourced: In Switzerland, wool is a byproduct of sheep farming, often discarded.
• Potential cost savings: Using waste wool could be cheaper than manufacturing geotextiles.
• Scalability challenges: Covering large glacier areas would require massive amounts of wool.

The Experiment: Design and Execution

The Keep It Wool project was developed by students Maxime Galley, Elliot Gaffiot, José Bastidas, and Léonard Duloube. They partnered with Swiss company Fisolan to fabricate two wool blankets with different densities: 400 and 750 grams per square meter. On June 22, 2026, they installed the prototypes on the Tsanfleuron glacier, along with a conventional geotextile cover.

Every two weeks, the team returned to measure ice and snow loss under each material and assess how the wool withstood the harsh high-altitude conditions. Expectations were cautious because no one knew how a natural material would handle months of moisture, wind, and freeze-thaw cycles.

Results: Wool Holds Its Own

By September, the data showed that the wool covers reduced melt by about half compared to uncovered ice. The performance was close to that of the synthetic geotextile, which is designed specifically for this purpose. The wool also survived the summer, though some degradation was observed.

The team is still analyzing the full dataset, but the preliminary findings are promising. The thicker wool (750 g/m²) performed slightly better than the thinner version, suggesting that density matters. However, even the thinner wool provided significant protection.

What This Means for Glacier Preservation

This experiment is a proof of concept, not a silver bullet. Covering entire glaciers with wool is impractical due to the sheer volume required. However, targeted applications could protect critical areas, such as glacier tongues that feed hydropower reservoirs or tourist sites.

Moreover, the use of wool addresses a waste problem: in many regions, low-grade wool has little commercial value and is often burned or discarded. Repurposing it for glacier protection could create a circular economy solution. Context on how this played out before sits in Wool Blankets on Swiss Glacier Cut Melt by Half, Study Finds.

The team plans to continue testing next summer with larger areas and different wool types. They also aim to study the long-term effects of wool on the glacier surface and downstream ecosystems. The background to this story is set out in Swiss Glaciers Shrink 20% in Five Years: Alarming Melt Rates. A related thread runs through Energy Utilities: latest articles.

Challenges and Limitations

Despite the encouraging results, several hurdles remain. Wool is heavy, especially when wet, making transport to remote glaciers difficult. It can also absorb water and freeze, potentially becoming less effective over time. Additionally, the material may degrade under UV radiation and require replacement every few years. Earlier coverage in UK Approves Jackdaw Gasfield Drilling Amid Energy Security Debate shows how the argument developed. A closer look at the same subject appears in Darwin Was Right: Science Confirms a New Carnivorous Plant.

Scaling up would require significant logistical coordination and funding. Nevertheless, the project has captured the imagination of researchers and the public alike, highlighting the need for creative solutions to climate challenges. Anyone following the wider picture can start with Africa's Renewable Energy Boom: China Leads Solar Colonization. The same theme surfaces in Interactive Map Shows All 140 Spanish Lighthouses in Real Time, which takes a different angle.

FAQ

The Keep It Wool experiment demonstrates that simple, nature-based solutions can contribute to climate adaptation. While not a cure-all, it opens a promising avenue for protecting glaciers with sustainable materials.