No glacier below 3,500 metres by 2050 and two thirds lost by 2100. What will happen in the Alps, where glaciers are melting and peaks such as the Matterhorn are crumbling due to a changing climate.
The world's ice is inexorably melting, from Antarctica to the Arctic, where Greenland lost 11 billion tonnes of ice sheet in a single day, to the Himalayas, where the world's highest peaks are melting twice as fast. But the mountains on our doorstep, the Alps, are also falling victim to rising temperatures, and their glaciers are recording unprecedented rates of retreat.
In the last 100 years alone, the Alpine glaciers have in fact halved in volume. Of that lost volume, 70 per cent has been recorded in just the last 30 years, as stated by glaciologist Renato Colucci of the National Research Council (Cnr). According to the expert, we will also no longer see any Alpine glaciers below 3,500 metres, which are destined to disappear within two or three decades. And of those above 4,000 metres, half will melt by 2050.
If we take the average temperatures of the last 15 years, these are not compatible with the existence of glaciers below 3,500 metres.Renato Colucci, glaciologist
Indeed, if temperatures continue to rise, the eternal glaciers of the eastern and central Alps could shrink considerably or even disappear entirely, surviving only in the western Alps, which are the highest. In this regard, a study conducted by Eth University of Zurich shows how global warming is already condemning the Alps across Europe, and presents two scenarios. In the worst case — that is, if nothing is done to halt the climate crisis — it is estimated that more than 90 per cent of Alpine glaciers could disappear by 2100. In practice, almost none would remain. If, on the other hand, countries were to meet the targets of the Paris Agreement, significantly reducing their emissions, two thirds of Europe's glaciers would still be lost by 2100. A sentence either way.
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These are dramatic predictions, but perhaps not entirely unexpected after the heatwaves of this summer, which set a series of temperature records in several countries around the world, in very many cities, and even on the peaks of the Alps. At the end of June, for example, the temperature at Europe's highest mountain hut, the Capanna Margherita at 4,554 metres, reached ten degrees without dropping below zero for several days. A temperature that experts estimate to be ten times higher than the average for this period. Alongside the excessively high thermometer readings, there were other warning signs, such as glacial lakes found by some mountaineers at altitudes between 3,000 and 4,000 metres, where there should be nothing but a expanse of snow and ice, or the critical situation of one of the Alps' most iconic peaks, the Matterhorn.
The Alpine glaciers in Europe and their recent evolution are among the clearest indicators of the climate changes currently under way.Daniel Farinotti, glaciologist, Eth University of Zurich
What is happening on the Matterhorn could serve as something of a symbol of the scourge striking the entire Alpine arc. With rising temperatures, alongside the glaciers, the permafrost is also melting — that is, the ground that remains permanently frozen, usually above 2,500 metres in altitude. When the permafrost melts, the rock beneath it loses stability and begins to crumble.
"When the mountains thaw in summer, rigidity decreases and soil sediments become soggy and unstable due to the water," said Jan Beutel of Eth University. "Cracks expand and move. Some keep moving in the same direction for years, and when at a certain point it becomes too much, they break." To explain this phenomenon, scientists at the University of Zurich who monitor the mountain have compared the melting of the Matterhorn to stracciatella ice cream, full of streaks of chocolate: when the chocolate pieces become softer, the ice cream loses its strength. And the same happens on mountains. For this very reason, 50 motion sensors have been installed on the Swiss side of the mountain, at 3,592 metres, to monitor the relative stability of the rock, thereby anticipating the landslides that are already increasing in frequency.
The Matterhorn will not collapse, but its iconic shape will undergo significant changes.Jan Beutel, researcher, Eth University of Zurich
This summer the Matterhorn saw its glaciers melt considerably, and a sign of this was felt in the valley below when the town of Zermatt — located at its foot on the Swiss side — was hit by a small flood with no rainfall. Indeed, as a section of glacier melted due to the high temperatures, the town was overwhelmed by water. Switzerland itself also saw its largest glacier — which is also the most extensive in the Alps — the Aletsch glacier, retreat by more than 3 kilometres since 1870.
Read also: The Stelvio glaciers are getting darker and darker
Compounding the situation of the glaciers is the phenomenon of albedo — that is, their capacity to reflect light. With the loss of the surface layer of snow, glaciers are left exposed and become darker due to the dust that settles on them — as is already happening on the Ortles-Cevedale range at Stelvio. As they darken, they absorb more heat (white is the colour that reflects the most, black the least), making them more vulnerable and thus accelerating the rate of melting.
Not only will the melting of glaciers permanently alter the morphology of ridges, peaks and valleys, but it will have significant consequences for people's lives. Indeed, even though they are hundreds of kilometres away, cities and entire territories depend on glacial water reserves for their survival, and their retreat will jeopardise the water security of millions of people. Examples of this phenomenon are already occurring, for instance at the foot of the Andes, in Chile, Ecuador and Peru, or in the Himalayas, where the inhabitants of Afghanistan, Bangladesh, Bhutan, China, India, Myanmar, Nepal and Pakistan depend on its glaciers for their water supply: in that region alone, one billion people.
That a first point of no return has been crossed is certain, but this does not mean that all is lost and that it is time to throw in the towel. On the contrary, countries must commit even more strongly to reducing their CO2 emissions and neutralising their impact on the planet in order to try to break out of this vicious circle that at times seems unstoppable. By doing so, it is still possible to save the glaciers on the world's rooftops and limit the impact of these changes on the people who depend on them — from the mountaineer who challenges the mountain, to the Alpine farmer who calls it home, to those who survive thanks to its water.
The future of these glaciers is at risk, but there is still the possibility of limiting future losses.Daniel Farinotti, glaciologist, ETH University