Record 450 Rockfalls Recorded in Mont Blanc Massif as 2026 Heat Takes Toll
CHAMONIX, France — The number of rockfalls recorded in the Mont Blanc massif this year is expected to reach 450 by the end of the season, nearly doubling the previous record and raising fresh questions about the stability of Europe's highest peak in a warming climate.
The figure, reported by Ludovic Ravanel, research director at the French National Centre for Scientific Research (CNRS), represents a significant escalation from the 300 rockfalls recorded in 2022, itself a record year. Ravanel described the numbers as "absolutely staggering," noting that just ten or twenty years ago, the area saw only a few dozen.
"Here temperatures have easily climbed above 30-35 degrees, and that obviously has impacts on the glaciers and on the permafrost," Ravanel told Euronews. "That is why this year we are recording unprecedented figures, for example in terms of the number of rock-face destabilisations and collapses."
Climate Change Blamed by Experts
Ravanel, who studies mountain geomorphology, attributes the upsurge in rockfalls to the effects of climate change, specifically the degradation of permafrost and the retreat of glaciers.
"A large majority can be attributed to the climate crisis," he told AFP, explaining that ice trapped in rock cracks acts as a "kind of cement holding the mountains together." When high temperatures cause this permafrost ice to melt, the rock loses its cohesion, leading to falls.
Ravanel also pointed out that melting glaciers exacerbate the problem. As glaciers lose mass, the pressure they exert on the rock walls—a stabilising force—is reduced, making the slopes more prone to collapse.
"We have shown that 80 or 85% of the scars on rock faces have formed over the past two or three decades," Ravanel said, referencing photographic records spanning nearly 200 years that document the progressive destabilisation of the mountain. "There is a very clear relationship between climate warming and the destabilisation of rock faces."
Fatal Year in the Alps
The record-breaking year has come at a high cost. In July, two Czech tourists were killed in a rockfall on the most commonly used route up Mont Blanc. In August, a 31-year-old man died in similar circumstances in the same massif.
Despite the dangers, authorities have not imposed restrictions on access to the high mountains. However, they have taken precautionary measures, including the closure of two shelters used by climbers on the standard route. Similar closures occurred in 2022.
Ravanel, for his part, has cautioned against complete prohibition, arguing that mountains are "a place of freedom." He also noted that while the number of rockfalls is rising, there has been "no surge in accidents" caused by them, attributing any increase in incidents to the growing number of people visiting mountain resorts.
Autumn Expected to Bring More Instability
As summer gives way to autumn, experts warn that the danger is far from over. Ravanel predicted that the biggest rockfalls of the year are likely to occur in the coming months.
"Even if the surface freezes over again, the enormous amount of heat from the summer of 2026 will continue to penetrate the ground until November, December, or even as late as January," he told AFP. The ground will continue to release this accumulated heat, destabilizing rock faces that have already been weakened by the summer's extreme conditions.
The 2026 season has highlighted an increasingly visible consequence of climate change in the Alps, transforming summer—once considered a safe time for mountaineering—into a period of heightened risk.