The climate crisis makes mountaineering “more dangerous”

Because of the increase in temperatures, the mountains become more and more moving and unstable. These changes complicate the daily life of mountaineering enthusiasts, which must change their practice and fear more for their safety. Explanations and testimonies.

On May 28, under the amazed eyes of the whole planet, the Valais village of Blatten disappeared from the map, buried under a gigantic avalanche of ice, mud and scree. An extreme event, which has marked the spirits, but which is part of a global and undeniable trend: our mountains suffer, and the culprit is known.

Indeed, global warming impacts mountainous regions in a particularly marked manner. In 2021, an analysis of the Federal Polytechnic School of Zurich (EPFZ) predicted that “chain reactions of climate change in the Alps will soon have an impact no longer occasional, but perpetual on everyday life”.

People who scroll the Alps know this well. Mountaineers and guides observe the mountains transforming, changing, which has repercussions on their practice – and their safety. “We can say that mountaineering is becoming more and more demanding due to the increase in objective dangers,” notes Rolf Sägesser, training manager summer with the Swiss Alpine Club (CAS).

“Climate warming very clearly affects our work,” adds Yannick Diebolt, mountain guide. We have to change our practices and we fear more for our safety ”.

An observation also shared by enthusiasts going to the mountains during their free time. “Conditions have clearly become more dangerous,” says André, who has been practicing mountaineering in Switzerland for ten years. In question: there is less and less snow, more crevices, which makes certain glaciers more open and difficult to cross. In addition, stone falls become more frequent and start earlier in the season.

More unstable routes

All this has very concrete consequences. “The rocky routes are increasingly unstable, because of the melting of permafrost at high altitude,” explains Yannick Diebolt. The mountain guide says that certain courses that were considered safe are much less. “A few years ago, many areas in the high mountains were held together by the freezing,” he adds.

André recently experienced it. During an exit on a glacier in central Switzerland, he heard landslides every two minutes, without seeing them. “It was a strange feeling,” he traces. Under these conditions, you shouldn’t approach the slopes too much, otherwise it becomes dangerous ”.

The risk is, in fact, never far. “We see more accidents, or almost accesses,” said Nicholas Bornstein, director of the Protect Our Winter (POW) association. “A friend recently received a big pebble on the foot. It may seem anecdotal, but he could have hit his head. ”

If he says he never takes risks, André recognizes that he must now adapt his routes. Or even give it up. “Before planning an outing, we call the owners of the hut, because they know the situation very well on the spot,” he explains.

Two years ago, for example, the mountaineer had to give up an outing in Valais, because of the falls of the stones. “It was just too dangerous,” he said.

This situation, Marine only knows it too well: “When we see that there are dangers, we do not leave”. She noticed that some routes, even those she has already taken in the past, become more and more technical. “It is too dangerous compared to our skills,” says the one who has a good ten years of practice to her credit.

Like André, she learns from people in the field before organizing an outing, which she did not do before – the card was enough. “Now we no longer know if a glacier is covered, or if the conditions allow us to leave,” she adds. “Some glacial routes become more and more dangerous and complicated to negotiate,” confirms Yannick Diebolt.

“It’s not easy to live”

Sometimes professionals must also give up certain outings, says Yannick Diebolt. What is certain is that these changes force them to take additional precautions. A situation that weighs on morale, although the preparation facing the unexpected has always been part of the profession. “I have the impression that there is more fatigue in many guides,” he says.

Not to mention the fact that the preparation is not only technical. “There is also a question of moral adaptation, of sadness to see this evolution,” continues the mountain guide. When we redone certain races that we did a few years ago, we can see that everything has changed. It is not necessarily easy or pleasant to live in. ”

All the people we interviewed agree on one point: this is not a novelty. But things go faster and faster. “This trend has been increasing since the last two or three summers,” confirms Nicholas Bornstein. “There is an obvious acceleration of these phenomena, echoes Yannick Diebolt. It is a rapid evolution and which goes in a disturbing direction. ”

Glaciers retreat at high speed

Glaciers are of course the most obvious example. “They are the ambassadors of global warming, illustrates Nicholas Bornstein. When we look at them, we realize the magnitude of the problem. It suddenly becomes very concrete. ”

“For the past ten years, we regularly have been going through the Aletsch glacier,” says André. It is much smaller, it seems completely different each year. It’s horrible to see. “

The figures are final. At the beginning of July, the glacier monitoring service (glamos) indicated that the ice accumulated in the Swiss Alps during the winter had already melted, when this should normally occur between August and September. In other words: any new cast iron this year will lead to a decrease in the size of the glaciers.

This situation also shakes up the seasonality of mountain activities. “Due to the decline in glaciers, the decrease in snow and the rise in the limit of permafrost, the high mountain season always begins earlier and generally lasts less,” said Rolf Sägesser. And the manager of the Swiss Alpine Club to add:

“In general, we organize our releases earlier in the season. We start to go up less at altitude in July and August, because it is less safe, ”says André. According to Nicholas Bornstein, more and more guides make the same decision.

The huts are not spared. According to a study of the case, dating from 2024, more than a third of the shelters could become unstable in the future due to the melting of permafrost. Forty structures are also threatened by landslides. “In the years to come, this situation will further increase and strongly occupy the case in planning, the definition of measures, but also financially,” says Rolf Sägesser.

The cost of inaction

Yannick Diebolt also recalls that things will get worse, if nothing is done: “The reality that professionals have been announcing for us for a long time occurred with us. These phenomena will not stop at the borders. We will be more and more affected, ”he says.

“For years, we have been brandished the costs of each measure to limit climate change, we wanted to prevent each action in the name of the economy,” he castigates.

And the mountain guide to conclude: “In Blatten, fortunately we listened to the scientists and evacuated the village before it was too late. Couldn’t we listen to them in general, to warn rather than repair? ”