In the alpine north of Italy, summer is approaching and the alpine ice must be protected from the coming heat. The Presena glacier, straddling Trentino Alto Adige and Lombardy, has lost more than a third of its volume since 1993. So for the past 10 years, a dozen men have installed several thousand square meters of canvas each year a technical material, which reflects light and prevents the ice from overheating below.
100,000 square meters of canvas installed this year
"There is a 10-degree difference between the air temperature and the temperature under the fabric," says Sonia Menicci of Carosello-Tonale, who spends more than a month at the top of the glacier to install the fabric. .
Each year, the surface to be covered increases. The team is currently installing nearly 100,000 square meters of canvas. Each of these bands is 70 meters long and 5 meters wide. It takes almost six weeks to install them in late spring, and as much in the fall to remove them.
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"A questionable operation if it is extended to very large areas"
"The fact of covering the glacier with a textile is something that has been proven to be effective. This allows the melting to be greatly reduced, from 50% to 70%. However, there are costs transport, implementation, which make this operation delicate and questionable if one wants to extend it to very large areas ", explains Samuel Morin, CNRS researcher Météo-France and author of Giec.
Such an operation has already been carried out in France, but on a very ad hoc basis. For example in the Chamonix valley, to prevent crevices from opening too quickly and blocking access for skiers or mountaineers.