When the Mer de Glace disappears …

REPORT – The melting of the glacier, not without consequences on biodiversity, forces us to rethink the emblematic Montenvers site.

From our special correspondent in Chamonix

Shock. For the visitor who has not been there for several years, the Mer de Glace, under the sorry gaze of the Drus and the Grandes Jorasses, looks more like a sea of ​​rocks. On each side, blocks of granite line the tongue of ice which, covered with deposits and debris, is no longer immaculate.

The hordes of Chinese and other mountain dwellers, at the start of autumn, casually surge in the little cogwheel train that takes them from Chamonix to Montenvers, at 1913 m. The site overlooking the Mer de Glace, which attracts around 350,000 visitors per year, remains the starting point for many races in the Mont-Blanc massif. But is this Chinese woman who immortalizes this moment with her smartphone aware that her children may never have the opportunity to attend this show?

According to a survey of, for one in two visitors questioned, such a visit falls under the “Last chance tourism”, even if most of them also try to understand what is going on there. For this English director and architect, “It is a grieving experience”, as he puts it bluntly. “When I was a kid, the ice was a few dozen meters below the cable car “, remembers Kim Bodin, mountain guide. Today, you have to descend 250 steps to be able to touch the ice and access the ice cave, whose galleries, with explanations, are dug every year in the glacier, on the site of Echelets.

53.3 million investment

Because this 40 km white tongue2 going up 7 km towards the back of Mont-Blanc, which makes it the largest glacier in France, is in perpetual motion. Since 1850 – date of the first photos – it has lost 250 m in thickness. “During the XXe century, the Mer de Glace has lost 15 cm of thickness per year. From 1990 to 2020, it accelerated: at Échelets, the glacier lost 137 m (4 to 5 m per year today) and is now only 80 m “, says Christian Vincent, researcher at the Institute of Environmental Geosciences (IGE) in Grenoble. Not to mention that it loses 30 m per year in length.

“Previously, we could make a return trip to the Couvercle refuge during the day; today, that is no longer possible ”, launches Olivier Greber, president of the Compagnie des guides de Chamonix, over a drink at the Montenvers refuge. This is not the only consequence of global warming. The local biodiversity is totally disrupted. “At altitude, there are fewer and fewer spruces, which are disappearing in favor of deciduous trees, more used to higher temperatures ”, explains Ludovic Ravanel, geomorphologist at the CNRS. The gradual disappearance of mountain pastures accentuates this phenomenon. “The “artico-alpine” animal species go up with the vegetation to higher altitudes. But the more they climb to the top, the less space there is, he continues. This is how species such as the rock ptarmigan, threatened by foxes, or the mountain hare, which can no longer protect itself from raptors under the ice, risk disappearing. ”

One can wonder about the advisability of these new installations, considering the threats that tourism poses to this so fragile nature.

But the mountain people have learned to adapt for a long time. Like the mayor of Chamonix, Éric Fournier, who launches: “The biodiversity of tomorrow will not be that of today; there will be fewer glaciers, fewer moraines and more forests. Tourism may not be the same, but we are not going to let ourselves be defeated. “

Hence the decision taken, after seven years of consultation with all local stakeholders, to redevelop the Montenvers site. From 2023, a new, longer gondola, replacing the current one, will make it possible to descend to the ice cave without having to take long steps. A new glaciorum, more complete than the current one, with an immersive experience, will also see the light of day. An investment that represents no less than 53.3 million euros for the Compagnie du Mont-Blanc, manager of the site. One can wonder about the advisability of these new installations, considering the threats that tourism poses to this fragile nature. Because the Mer de Glace will have – in the best case – lost 80% of its surface in 2100, or even completely disappeared by this time in the most pessimistic scenario, estimates Christian Vincent, on the basis of his simulations. And Mathieu Dechavanne, president of the Compagnie du Mont-Blanc, to put into perspective: “There will always be the Grandes Jorasses at 4200 m.”

Le Figaro

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