Mr. Huss, which glacier did you last stand on?
I was last on the Rhone Glacier. What I saw there was very extraordinary. This summer's never-ending heat waves have taken enormous toll on the glacier. Within a month, more than four meters of ice thickness was lost on its tongue. The cumulative loss over the entire year will certainly be very high.
How many glaciers have disappeared in recent years?
Between 2016 and 2023, 160 glaciers disappeared in Switzerland. That means a decline of around ten percent. We will lose many more glaciers this summer.
How many of the approximately 1,300 Swiss glaciers will still be there at the turn of the century?
In the best case scenario, the ice volume of glaciers will decrease by 70 to 80 percent by the end of this century. In our extreme scenario, the ice is completely gone.
The permafrost above the glaciers is also thawing. So will there be more landslides in the future like in the Lötschental in Valais, where the village of Blatten is now buried under rubble?
The permafrost warms up and thaws to greater depths every year. This means there are more rock falls and rock falls. This endangers mountaineers and hiking routes. In the case of large landslides, other factors come into play. The disaster in Blatten is not just a consequence of warming in recent years. The specific geological conditions also played a role. But climate change makes such events more likely.
What consequences does glacier melting have on the water supply in the Alps and beyond?
The consequences are not yet clearly visible. Because of the intense heat, the melting is currently progressing extremely rapidly. This means that a large additional amount of water comes from the high mountains. The negative consequences of ice melting are therefore still masked. But every day and year of high melting rates reduces the water reservoir that was naturally created decades and centuries ago. This puts us in a situation in which heat waves will have significantly greater impacts than they do now. The meltwater then stops flowing in the middle of summer - that is, in the dry phase in which we urgently need this water to maintain the levels of the rivers and lakes to some extent.
When will the point be reached at which the water supply from the Alpine ice buffer will inevitably decrease year after year?
We are pretty much now at this peak point in the Alps called “Peak Water”. The maximum amount of water is currently flowing away from the glaciers. From then on, the runoff volumes decrease until all the glaciers have melted. As long as we still have a certain amount of ice, there will be something else that will help reduce the water shortage. But this inflow becomes smaller and smaller as the ice area becomes smaller.
In a hot summer like this, what percentage of the Rhine and Rhone runoff comes from glacial ice?
An exact determination is difficult because the water is used intensively along its path. For example, it is stored in reservoirs and used for irrigation. According to our estimate, the proportion of glacier water in the Rhine in August is seven to eight percent and in the Rhone around 20 percent. These are averages. In extremely hot years, the proportion in the Rhine can rise to up to 20 percent.
So the problems of navigation on the Rhine will worsen if less and less glacier water flows in during the summer?
Yes, these problems will become significantly more pronounced in the next few years, especially as extreme weather events continue to increase. This will extend the low water periods in the Rhine and will pose major challenges for Germany and Switzerland. Switzerland obtains many goods via transport on the Rhine.
Water plays a major role in Switzerland's electricity production. Are there any problems?
At the beginning of August, the Beznau nuclear power plant had to temporarily shut down its two units due to the high water temperature. River hydropower plants can often only operate to a limited extent when water levels are low. However, we do not expect that we will have less water overall in Europe over the course of the year. The point is that water is not available in sufficient quantities at all times. So far, the high mountains have held on to water in the form of ice and snow at times when we already have enough water. In summer, when it is dry and hot, it releases the water again. This effect will increasingly disappear in the future.
What conflicts threaten between hydropower, agriculture and ecology when water becomes increasingly scarce in summer?
These conflicts are already being hotly debated today. The power plant operators strive to fill the reservoirs in summer so that in winter, when there is less solar energy, they can use the stored water to produce electricity that can be sold more easily. In the future it should actually be the other way around. Since the glaciers gradually lose their natural storage function, the reservoirs would have to be emptied in summer. The many plants and fish that depend on water also need stable drainage.
What role does glacier melt play in sea level rise compared to Greenland and Antarctica?
If all glaciers melt, sea levels are expected to rise by 30 to 40 centimeters. If the ice sheets of Greenland and Antarctica melt, we are talking about a rise of seven and 60 meters respectively. However, Greenland and Antarctica are reacting much more slowly to global warming than the glaciers, whose retreat is currently contributing significantly to sea level rise.
What does the melting of glaciers mean for tourism in the Alps?
The mountain areas attract tourists with their glaciers. So you lose an identifying feature. A new landscape is emerging with new valleys and mountain lakes. It remains to be seen whether this will ultimately attract fewer people.
In some places, glacial areas are covered with fleeces to protect them from the sun. What do you think of it?
Glacier fleeces are only available in ski areas. They serve to preserve the ice at critical points a little longer and so the slopes can be better prepared for guests in winter. This is a purely economic initiative by the ski resort operators, which is often incorrectly interpreted as a glacier rescue operation.
What should Alpine countries do to mitigate the future consequences of water shortages?
They would have to start building new reservoirs now. In this way, the lost effect of the glacier as a natural water reservoir could be compensated for. There is often and justifiably opposition from environmentalists to such projects. It is not easy to create a reservoir in an undeveloped valley. In certain regions you probably won't be able to avoid it.
If you could impose a single instrument, which would have the greatest impact on glaciers?
That's very simple: climate protection. If this is increased, it will also help the glaciers. Their disappearance is only a small but clearly visible expression of global warming. Heatwaves and droughts have a much larger and more widespread impact on people.
Will this hot summer increase people's awareness of climate protection again?
I hope so, but I'm not overly confident. Problems such as wars and economic crises are always at the forefront because they have an immediate impact and require a direct response. The climate crisis seems less urgent in comparison. And as soon as it gets cooler again, you forget about the problems again.
They have been documenting the retreat of glaciers for years. So things are always going downhill in your field of research. How do you endure this without becoming resigned or cynical?
That's a good question. I always hope that a year will come that won't be so bad. But then one piece of bad news follows the next. On the other hand, this also offers the opportunity to continually point out how serious the situation is. And I don't just mean the glaciers.
