Europe’s glaciers melt extreme

Punishing summer heat waves caused the thaw, but the process of initiating a rapid thaw began months ago.

Jacquemart said there was less snow than usual in the winter, and by the end of the season there was only half of what it normally would be, limiting the growth of the glacier. For example, the Gries Glacier in Switzerland had its lowest snow cover ever in April, about 53% below average.

In late winter and early spring, large amounts of dust from the Sahara covered the snow surface and darkened the glaciers. Rather than reflecting sunlight back into space, the darker surface absorbed more sunlight, helping to warm the fallen snow.

The spring was also unusually warm and dry across much of Western Europe, with little snow in the glacial highlands.

Then the summer heat kicked in early on. Southwestern Europe hit the highest average May temperature on record in 55 years. Europe then experienced her second warmest June on record.

“Intense heat and lack of precipitation are putting glaciers in an unprecedented state,” said Jacquemart of the Swiss Federal Institute for Forests, Snow and Landscape. The fact that the situation is very bad everywhere in the European Alps is alarming,” she said.

Satellite data shows that some glaciers are shrinking after a mid-June heatwave brought temperatures 10 degrees above average in some areas. After about a week of unusually high temperatures, the Savione Glacier, which supplies water to the hydroelectric reservoir, has lost about 35% of its snow cover, says glaciologist Mauri Pärt.

Bare glacier ice melts 50% faster than when it is covered with snow, so the loss of snow cover early in the melting season is problematic. Melting accelerated in July as the heat wave continued.

“July’s glacier melt was higher than the full-season maximum ever recorded,” Fisher said.

Satellite data show that the Rhone Glacier, which flows into the Rhone River, is melting significantly from June to July. By July 15th, the glacier’s snowline had reached 2950 meters. This is about 150 meters higher than normal for this time of year.

Egli remembers running with his father along the snowy ridges of the central Swiss Alps when he was 12. This was one of his first mountaineering adventures before competing professionally. Zurich could be seen in the distance from the summit. Even in summer, the mountain slope facing the city was covered with snow.

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Twenty years later, he found the area to be mostly rock and rubble, with both ridges and summits devoid of snow cover. The glaciers leading up from the summit were bare of ice as temperatures became too hot to hold the snowpack. Ice and firs, or thick snow left over from the previous season, also disappeared from the ridges.

Climbing practices have already changed in the last few decades, he said. Some routes only become safe in April or May, before the trail becomes too dangerous.

Egli said he began to realize that “some of the glaciers we’ve ridden over will no longer exist.”

Fisher said the changes are consistent with long-term changes in climate. Since the 1980s, temperatures in the Alps have risen by 0.2 degrees Celsius to 0.5 degrees Celsius every decade, having a significant impact on spring and summer snowfall and melting.

“Over the past 20 years, snowless summers have become the norm and the melting season has become longer and longer,” Fisher said in an email.

According to the Alpine Ecosystem Research Center, the duration of snow cover near the valley floor in the Northern Alps has shortened by five weeks since the 1970s. By 2050, snow cover could decrease by another 4-5 weeks.

In addition, valley floors and hills can add 15 to 30 hot days. Today, the region experiences such temperatures for only 2-5 days.

Professor W. Tad Pfeffer of the University of Colorado Boulder said: “The Alps have been hit very hard. Alaskan glaciers are shrinking, but not as much as the Alps.”

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On rare occasions, rapid melting can lead to exceptional events such as the collapse of the Marmolada Glacier in Italy’s Dolomites region. During a July heatwave, a glacier mass separated from the mountain, causing an avalanche of ice, rock and debris beneath it, killing 11 hikers.

“All Alpine glaciers are suffering from heat, accelerating the melting process. Dolomites glaciers are generally smaller and more susceptible to climate change,” says Mauro, a glaciologist at the Alava Avalanche Center. Mr Wald said.

Outside the Alps, other mountain glaciers are also experiencing record melting. Glacier melt in Norway’s Svalbard archipelago was the highest on record during the first two months of summer.

“Without this, we wouldn’t have seen this. [human] It’s the impact on the climate,” Pfeffer said. “What was like a once-in-a-lifetime event started to become kind of routine…we’re looking to the future.”

Washington Post