Long considered the safest time of year for mountaineering, summer has in recent years become a high-risk season. In the Alps, 2026 already holds a worrying record: 450 rockfalls in the Mont Blanc massif alone since the start of the year.
Something never seen before, says Ludovic Ravanel, geomorphologist and research director at the CNRS at Edytem: "Here temperatures have easily climbed above 30–35 degrees, and that obviously has impacts on the glaciers and on the permafrost. That is why this year we are recording unprecedented figures, for example in terms of the number of rock-face destabilisations and collapses."
The previous record dated back to 2022, with 300 rockfalls recorded that year. This phenomenon is directly caused by climate change, explains Ludovic Ravanel: "These photographs cover nearly 200 years of climate warming. By comparing them with one another, we are able to identify the scars, that is to say the areas where rock faces have been destabilised. We can quantify them in terms of volume. And we have shown that 80 or 85% of these scars have formed over the past two or three decades. So there is a very clear relationship between climate warming and the destabilisation of rock faces."
