Around the globe, in all latitudes, at all altitudes, glaciers are receding and disappearing at a rapid pace. At a speed that often exceeds even the most alarmist previsions made a few years ago. This tendency has been recently confirmed by a study of the French Alps carried out by researchers of the University of Savoie, located near Chambery.
When we talk about melting glaciers and global warming we often think of faraway polar regions. But here we are in the heart of Europe, close to Mont Blanc, and the surface area of glaciers is shrinking remarkably.
According to the new research, glaciers in the French Alps have shrunk by a quarter in the past 40 years. In the late 1960s/early 1970s, the ice fields creeping down Mont Blanc and the surrounding mountains of the Alpine range covered some 375 sq km. By the late 2000s, this area had fallen to about 275 sq km.
This mirrors findings of glacial retreat in other sectors of the Alps which sit across the borders of several nations, but predominantly Switzerland, Austria, Slovenia, Germany, France, and Italy.
The new French Alps Glaciers Inventory by the University of Savoie was produced by researcher Marie Gardent, and colleagues.
“We’re standing in front of the Bossons glacier, that starts 1500 metres up, but 40 years ago it was almost down to the valley floor. The general retreat of the glaciers is due to the global warming we all talk about.
Summer temperatures are higher, and there’s less snow in winter. The consequences for the glaciers will directly impact on our water resources.
The glaciers around the Alps are huge freshwater reservoirs.
Another consequence is that sudden pockets of water and lakes can appear which, when they rupture, can cause floods. A glacier retreating frees up unstable rock debris and mud that can slide dangerously at any tim.,” says Gardent.
The University of Savoie has one of Europe’s leading centres devoted to the study of the Alpine environment, with around 60 researchers. The recent study assessed around 600 glaciers. Marie Gardent used map archives, satellite imagery and aerial photographs.
“This is the glacier that provides the river Isere with its source. The violet line shows how big it is was in 1850, then in 1970, and the blue line shows where it is today.
To find out where the glacier was in 1850 we used the marks it had made in the landscape. For 1970 we had old maps, and for today’s position we’ve used aerial photography. Thanks to our software we estimate on average glaciers have lost 26% of their cover in the last 40 years, from 1970 to today, and 50% if we go back to 1850,” she says.
Marie Gardent adds that the general retreat of Alpine glaciers since 1850 has considerably accelerated during the last 20 years, and this trend risks worsening in the future if the climatic conditions of the planet do not change.