Defeat has already been admitted at the valley station of the Diavolezza cable car in Switzerland. Even before climbing to the peaks, an exhibition called “VR Glacier Experience” offers visitors the opportunity to measure the effects of climate change on glaciers, “understand the importance of water and imagine models up to the year 2100.” A few South African tourists, fully equipped for the high mountains (backpacks, ropes, ice axes, etc.), put on a virtual reality headset and discover a short animation in which the epithet “inevitable” stands out: “If we let’s nothing do, declaims a valley resident with a gloomy expression, even a giant like the Morteratsch glacier will disappear in a few decades, there is no doubt about that. »
A few minutes later, at an altitude of 3,000 meters, the glacier cirque in front of the eye has already lost its splendor. The Morteratsch glacier towers over the Piz Bernina massif (4,048 meters), the highest point in the Eastern Alps, which marks the border between Switzerland and Italy, and initially surprises with its color palette. Gray and charcoal everywhere, a far cry from the cobalt blue hues of the seracs previously associated with this type of landscape.
“The problem is right there. The ice melts faster and faster and wears away the rock on which it slides and is mercilessly ground down by its weight. The result is an increase in mineral dust, explains Hans Oerlemans, a world-renowned Dutch glaciologist and winner of the prestigious 2022 Balzan Prize for his pioneering work. A glacier is an autonomous dynamic system in which thermal differences cause wind to constantly blow. This dust is transported and deposited on the increasingly darkening glacier, causing the albedo effect to decrease. White, a glacier repels the sun’s rays; dark gray, it absorbs them. »
In the three decades since he installed measuring stations on glacier systems around the world, the researcher has recognized the evidence. “They will disappear, but we can slow their predicted disappearance” – this risk of large-scale disappearances was raised in the debates at the Polar Summit, which took place in Paris from Wednesday 8th to Friday 10th November.
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Originally a geophysicist, Hans Oerlemans quickly turned to studying ice, fascinated by the effects of weather on their long-term behavior. Back in 1989, in an article published in the journal Climate Change, the man who is now a professor of climate dynamics at Utrecht University predicted sea level rise under current global warming conditions by emphasizing the melting of the Arctic Circle ice caps and the thermal Expansion of sea water. “It was almost shocking at the time,” he says, “but our initial forecasts are not that different from what we see today.” Today. »
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