Hut warden on climate change "The mountains are beautiful, but they can also be brutal"

A gigantic rockslide changed Val Roseg in the Engadin - and everyday life at the Tschierva hut. Hut warden Caroline Zimmermann experiences how climate change is altering the Alps and her everyday life.

Even after 25 years, there are still moments when Caroline Zimmermann is surprised by the mountains. For example, when several centimetres of snow fall in July. Then she stands on the terrace of the Tschierva hut, throws a handful of snow into the air, which her dog Jack catches in mid-air, and says: "It's very, very rare that it snows like this in July."

Caroline Zimmermann is the hut warden at the Tschierva hut, at the foot of Piz Tschierva near Pontresina GR. "The mountains here are beautiful," she says on the terrace in front of her hut, talking about how she was drawn to the mountains with her parents as a child.

After her apprenticeship as an optician, she worked at various huts in the Engadin and Bernese Oberland for nine years - until she stayed at the Tschierva hut. Today she is 53 years old and has been here every summer for 25 years, from June to October. In winter, she works as a florist in a five-star hotel in St. Moritz.

Anyone who has been doing a job for so long also knows about the changes that happen over time. Zimmermann knows that guests have become more demanding: They want fewer dormitories, but more privacy and more luxury. Or the fact that people now write a lot more e-mails than they used to.

And here, at 2584 meters above sea level, Caroline Zimmermann also feels the effects of climate change in a very tangible way. Temperatures are rising and the weather is becoming increasingly unpredictable. This year, the zero degree mark in June rose above 5000 meters for the first time since measurements began in 1954.

"We are extremely dependent on the weather," says Zimmermann. If it suddenly snows after a very hot June, the mountains become more dangerous. Mountaineers have to cancel or postpone tours. This makes planning more difficult for Zimmermann. Because even if guests change their plans at short notice, the food still has to be bought, flown to the hut and prepared.

When it gets warmer, the season generally gets shorter and the conditions on the mountain are not always ideal. Zimmermann then has to get the maximum number of overnight stays out in the shortest possible time. "But that's never the number of overnight stays you should have in order to make a living," she says.

However, climate change became most visible on a single morning: Sunday, April 14, 2024, at 6.56 am. Then came the mountain. 5.5 million cubic meters of ice and rock broke loose on Piz Scerscen, thundering down into the valley and taking another 3 million pieces of debris with it on the way.

Caroline Zimmermann was not in the hut at the time, as it was not yet the season. Friends of hers sent her pictures. At first, she thought it was just a bit of scree coming down again. This has happened before. "But when I saw the extent of it, it scared me."

Thawing permafrost played a role

Because the area where the landslide started was located in a permafrost area and water emerged from the broken rock immediately afterwards, it was quickly assumed that thawing permafrost could have played a role. Permafrost is permanently frozen ground that has a temperature of 0 °C or below all year round. It works like the glue that holds a mountain together.

If it gets warmer due to climate change, the permafrost thaws. A report by the Swiss Permafrost Monitoring Network recently showed that 2024 was the warmest year for permafrost since measurements began 25 years ago. At a depth of ten meters, temperatures rose by up to 0.8 degrees Celsius.

A few months after the rockslide, in August 2024, the WSL Institute for Snow and Avalanche Research published a report in which it confirmed that the thawing of permafrost had caused water to penetrate the rock, which contributed to the rockslide.

The Tschierva hut was spared from the landslide and there were no injuries. Since then, however, the area around the Tschierva hut has changed. Anyone hiking up to the hut today - along the river, through forests with trees overgrown with lichen, past day trippers on e-mountain bikes - will not notice much of this at first.

But further up, the deeper into Val Roseg you go, the more visible the extent of the landslide becomes. The almost six-kilometre-long cone of debris. The streams that make their way through the rock. The glacier, broken off and covered by debris.

Since the landslide, tours to Piz Scerscen and Piz Roseg have also been discouraged, as the route leads through the landslide area. This has a direct impact on the Tschierva hut: in the past, mountaineers often stayed for several days and made various high-altitude tours. Today, most only stay one night.

This reveals a reality that has become increasingly clear in recent years: even the mountains - once a symbol of stability and tranquillity - are changing. And sometimes they plunge into the valley. In Blatten, in Brienz, in the Lötschental and in Val Roseg.

And ways are needed to deal with these changes and with the landslides that are increasingly becoming part of everyday life in the Alps. This is nothing new for hut warden Caroline Zimmermann. Her fascination with the mountains has always included a respect for their power - long before the landslide.

"The mountains are beautiful, but they can also be brutal," says Zimmermann and talks about how at least one person who has spent the night in her hut has an accident on the mountain every year. People she sometimes spoke to the night before and laughed with. "Of course it gets to me," she says. But afraid? No. "Otherwise you wouldn't be able to do anything."

The guests in the Tschierva hut are also preoccupied by the landslide. "Affected" and "impressive" are words that can be heard from the mountaineers in the hut. Zimmermann says there are even people who come to the hut just to look at the debris cone.

Even if they don't go up Piz Scerscen or Piz Roseg, mountaineers and hikers are affected by climate change in the mountains. Tours are becoming more difficult due to loose rocks and the melting of the glacier. "You can see how everything is becoming extremely unstable," says Zimmermann. "Today, you have to be more careful if you want to hold on to a rock."

Piz Scerscen is also still on the move. The hut warden says that you can always hear stones rolling across the glacier. The WSL Institute for Snow and Avalanche Research also writes that "so far, most of the potentially unstable rock mass has fallen, but not all of it". Something could happen again at any time.

Although the hut itself lies outside this danger zone, it is still not safe from climate change. Behind the hut, the ground is shifting and the water is moving more. "In heavy downpours, the cellar is under water," says Zimmermann.

Every third SAC hut is affected by climate change

Last year,the Swiss Alpine Club SAC investigated how climate change is affecting mountain huts. The conclusion: of 152 SAC huts, over a third could become unstable in the future due to thawing permafrost.

42 huts are also potentially threatened by rockfalls. The water supply will also become more difficult and hiking trails and the surroundings of the huts will change. By 2050, only 10 percent of the 152 huts will still have a glacier in sight; by the end of the century, none of them will.

According to the SAC, in order to meet these challenges, 5 million francs would have to be invested in climate change adaptation measures every year until 2040 - a total of over 100 million francs. "At some point, the SAC will have to consider which huts are still worthwhile," says Zimmermann.

Until then, one thing is clear to the hut warden: she will carry on. And tries to adapt with the Tschierva hut. She has set up double rooms in the hut to attract guests who appreciate comfort - and thus open up new sources of income. She drains the water behind the hut.

"The hut is like my child", says Zimmermann, "I couldn't imagine doing anything else". She will only consider quitting when she no longer feels like it. So far, that's not the case - the conversations, the encounters, the closeness to the people in the hut make sure of that. "People are open up here, it's much easier to get into conversation," says Zimmermann.

Incidentally, her favorite time of the day is between 10 and 11 a.m., when breakfast is made, the hut is cleaned and it is quiet. That's when she sits down on the terrace with her team and has a coffee.

"Life goes on," says Caroline Zimmermann. "And we have to make the best of it."

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