The World Glacier Day draws attention to the worldwide melting of glaciers. If you could write an open letter to humanity, what would you say in it?

Glaciers are a key feature of our mountain landscape, and mountains are an important part of our reality as human beings. But today, we are witnessing their disappearance at an alarming speed. While glaciers have always undergone cycles of fluctuation—growing and shrinking over thousands, even millions of years, they are now shrinking at a completely unprecedented pace.  We are losing something that is not only visually and culturally important but also critical for ecosystems. Glaciers are key sources of water for many regions around the world. Their rapid decline reflects our enormous impact on the planet—just like deforestation, where trees that took centuries to grow are cut down in an instant. I would say this is a sign of our arrogance. We have the power to change our environment so drastically, and yet we often fail to acknowledge the consequences. We must take action.

How do you deal with researching something that will probably no longer exist in a few decades?

Not all glaciers will disappear. Large glaciers—like those in Alaska, the high mountains of Asia, or the Andes—will survive. But climate change has given a new urgency to glacier research. While I didn’t start my work because of climate change, fundamental scientific questions are more relevant now than ever. Glaciers are beautiful. I wish more people could see them, to witness firsthand what is at stake.

How would you explain to a child why glaciers are important for our future?

A glacier is a huge mass of ice that sits in the mountains—and it moves! If it didn’t move, it would not be a glacier. This movement is essential to how glaciers work, how they melt, and how they interact with the environment.

Think of a glacier as a giant water tank that only releases water when it’s warm—just when we need it most. In places like the Alps, glaciers provide water in summer when there is little rainfall. But because of warming, glaciers are now melting much faster, releasing more water than usual. Eventually, if they disappear, there won’t be enough water left for us in the future.

Amid the ongoing climate change, how would you imagine the best- and worst-case scenarios for the glaciers and our planet? Could there be a “safety net” waiting to be discovered?

The word “discovery” makes me uneasy in this context. It often leads to discussions about geoengineering—covering glaciers with artificial materials to slow melting. But this is not a real solution. It might work for small ski resorts, but not on a large scale. The only way to truly protect glaciers is to address the root cause of the problem: reducing emissions.

We do know that some glacier loss is inevitable. Even if we stopped all emissions today and kept the climate as it is, glaciers would continue shrinking for decades due to their response time. In the Alps, for example, studies estimate that at least half of the glacier mass will disappear regardless of what we do now.

The best-case scenario? That we manage to slow the process enough to preserve some of them. The worst-case scenario? That we continue on our current path and lose most glaciers in the Alps by the end of the century. Some regions, like the Himalayas or Pamir, will retain their glaciers because they are much larger, but in many places, we will have to accept that glaciers will be gone—and with them, critical water sources.

Research is often limited by technological possibilities. Do you wish you had one tool that could revolutionize glacier research?

I think we have it now—artificial intelligence. I recently submitted a research proposal with AI scientists to use machine learning in glacier modeling. Right now, our models are complex and computationally heavy, taking months or even years to run some of the simulations. AI has the potential to revolutionize this, speeding up calculations and allowing us to run models over larger areas and perform ensemble simulations.

Your field of work combines natural science with adventure. What does a typical research day on a glacier look like?

Glacier work is dangerous. The first days are all about setting up camp—digging a toilet, setting up the kitchen, preparing equipment. Then, we wake up early, have breakfast with our local team, and head to the glacier. The work is exhausting, especially at high elevations. Acclimatization is crucial and safety is always on our mind, but even then, the physical strain is intense. On debris-covered glaciers, like those in Nepal, the terrain is particularly tricky. Walking on unstable rocks and carrying heavy equipment feels like meditation—your focus is completely on every step.

Did a particular experience on a glacier mark you?

I will never forget the time I broke my leg on a Chilean glacier. I was alone for more than an hour before rescue arrived, and as darkness fell, I experienced something new—true existential fear. I had never thought about my own mortality so directly before. But that accident solidified my path. It was during my first postdoc, and despite the injury, I decided to stay in Chile instead of returning to Europe for treatment. That was the best decision I ever made. It taught me resilience and opened up an entirely new perspective on the country and its people.

World Glacier Day is also about the glaciers’ impact on communities and water security. Can we humans build an emotional relationship with glaciers?

Communities living close to glaciers often have a deep connection to them. In some places, glaciers are even considered sacred, not to be disturbed. But the further downstream you go; the less glaciers are understood. Some people in lowland valleys don’t even know what glaciers are.

This presents a dilemma. People should respect and appreciate mountains, but does greater awareness mean more tourism? I have witnessed troubling things—mass tourism at 4,000 meters altitude in Nepal, for example, where visitors have porters carrying their suitcases (not even backpacks) and are ordering pizza and soft drinks from down-valley at such extreme altitudes. So, what does it truly mean to “know” the mountains? It must come with respect and humility. Mountains teach humility at every level—from the sheer scale of their existence to the personal experiences of those who venture into them. They are both powerful and fragile, and we must protect them.

Despite our technological advancements, I often feel that we are increasingly unprepared to live on this planet. In fact, the more proficient we become technologically, the more disconnected we seem from the natural world. I wish humanity would invest as much in awareness, wisdom, and respect for the environment as we do in technology.