Inside a scientist’s quest to understand why climate change is making Europe’s highest peak more dangerous

In July 2020, a young climber was trapped in a brutal rockfall on “Death Row.” on Mont Blanc, the highest peak in Europe. The Estonian was trapped in the steep, open ravine, halfway along a narrow path that runs through it. She was curled up in a fetal position, her backpack protecting her as rocks, dirt and chunks of granite, some as big as bricks, fell. The projectiles bounced off his backpack, and one even hit his helmet, making a loud noise on its metal surface. This short stretch of the north face of Mont Blanc in the French Alps is the Grand Couloir, and it ranks as one of the most dangerous in the world for the thousands of climbers, professional and amateur, who seek the approximately 16,000-foot summit of the mountain every year.

“He is very lucky that the rocks that fell were not larger, as they could well have been,” explains Ludovic Ravanel, a French geomorphologist and veteran mountaineer.. Surprisingly, the woman, whose ordeal was captured on a youtube video— was practically unharmed and was eventually removed from a nearby location by the mountain rescue service.

Rock collapse – Goûter Route, Couloir Goûter, Mont Blanc

“Most people who climb Mont Blanc are not aware of the risk they are taking,” says Ravanel.

About 100 Every year people die in the Mont Blanc mountain range, which includes 11 independent peaks. In the French ascent to the summit of Mont Blanc alone, an average of ten climbers have died each year since 2018. The death toll on Mount Everest. at approximately 29,000 feet, a peak considerably higher and more complex to ascend than those of the Mont Blanc mountain range.

The explanation for this alarming number of fatalities is, in part, the number of adventurers who each year try to reach the summits of Mont Blanc: about 20,000. that total is More than 25 times the number of climbers reaching the summit of the popular Nepalese side of Everestand includes many novices, some of whom happily attempt climbing without guides. And then there is the particularly lethal Grand Couloir.

Ravanel probably understands the dangers and dynamics of the highest faces of the legendary peak better than anyone. The 42-year-old grew up in the town of Chamonix in the French Alps, at the foot of Mont Blanc, where for generations his family had trekked across the granite and glaciers of the mountain range as alpine guides. As a teenager, Ravanel devoted himself to the southwestern corner of the Alps as a naturalist, climber, and amateur mountaineer. And he climbed Mont Blanc for the first time aged just 17, before maturing into one of France’s leading alpine climbers, one who competed on his national team in the 1990s.

But the deaths of several friends and teammates on the climb, and some of his own close calls, gave him pause and sent him back to the classroom. The 20-year-old began studying geology in 2002 at the University of Savoie Mont Blanc, in Chambéry, France, before realizing that it was the glaciers and ice shelves of the high peaks (the thin ice on the faces of high altitude) those who shot the most. your curiosity. “I fell in love with science,” says Ravanel, a geomorphologist who is now on the faculty at the same institution. The university is dedicated to the study of the Alps, one of the longest mountain ranges in Europe that spans eight countries.

After Ravenel moved into geomorphology, he focused on the way global warming was altering the conditions and configurations of the alpine landscape before his eyes. Since then, he has made the impact of climate change on Europe’s highest slopes his life’s work. In recent years, he has watched rockfalls skyrocket as global warming melts glaciers and ice fields in the Alps, altering the terrain of the mountains. The Estonian woman in the video may not have realized it, but she almost became a victim of the climate crisis.

“The entire Alps have been hit hard by the climate crisis, more so than most places in the world,” Ravanel says, somberly.

“In 2022 and 2023 alone,” he continues, “Mont Blanc has lost 10 percent of its ice. Since 1950, half.”

Ravanel wonders aloud what will be left of Blanc’s glaciers when his three children, all mountaineers themselves, reach adulthood.

Ravanel, a wiry man with an angular face and scraggly beard, explains that ice is the glue that holds together the upper regions of peaks over 8,500 feet, such as Mont Blanc. When this glue dissolves, the mountains begin to move and crumble. “The mountain becomes less stable: the glaciers, the moraines, the ice shelves, the rock walls, everything,” he says.

Rockfalls on stretches of Mont Blanc have become so dangerous in the height of summer that experienced guides (as is Ravanel) refuse to take clients there. In 2022, the mayor of Saint Gervaisa French village on the lower slopes of Mont Blanc, proposed that thrill seekers pay a deposit of 15,000 euros (about $15,600) before attempting to climb Mont Blanc: 10,000 euros for the costs of the rescue operation and 5,000 euros for funeral fees. The idea was that if they returned safely, and did not need an emergency rescue, they would be refunded in full. Small communities like Saint-Gervais struggle to bear the financial burden of these types of emergency services, he said.

The dynamics at work on Mont Blanc are multiple, as Ravanel and his colleagues have found. Glacier crevasses are becoming more frequent as the ice shrinks and shifts. Summit ridges become narrower as the once-solid terrain erodes. And snowy slopes have transformed into steep, exposed ice as the snow melts and refreezes. Research teams at the University of Savoie Mont Blanc are only now discerning patterns and charting the frequency of extreme mountain events.

Using high-tech sensors and ground-based laser scanners, Ravanel and his fellow scientists are studying exactly how temperature fluctuates and how permafrost reacts to it. Ground permafrost that has been frozen for years (perhaps even millennia) is warming and eventually melting as temperatures rise. By placing sensors in deep wells, scientists discovered that the permafrost of the French Alps is warming 1 to 1.5 degrees Celsius (approximately 1.8 to 2.7 degrees Fahrenheit) per decade. He studies on permafrost degradation and rock slope instability have found that warm water from melting permafrost, or from rain and melting snow, seeps into colder rock structures. The pressure builds and fractures the rock, causing rockfalls and avalanches. And water accumulating at the base of glaciers can even cause ice to slide, Ravanel says, noting that this phenomenon has now disappeared. mountain refuges and bridges.

Studies published by Ravanel, often conducted as part of a larger scientific team, have found 25 geomorphic changes related to climate change that may influence mountaineering. BesidesRockfalls on peaks affected by permafrost are much more frequent when temperatures rise and thaw begins. The scientists found a daily correlation between the frequency of rockfalls and air temperature; On average, only two hours separate the rise in temperature and the subsequent rockfall. another study shows that on some of the faces of the Mont Blanc mountain range, the annual rate of erosion of the 18.3 millimeters (3/4 inch) rock walls between 2005 and 2022 is one of the highest rates in the Alps Europeans. The same team also identified that rockfall between 2016 and 2022 was almost nine times greater than between 2005 and 2014.

But the region’s native son also always has the broader alpine community in mind, from mountaineers to alpine village populations. “Even today, when I look at a rock face or a glacier,” he says, “I think of it first as a mountaineer and then as a scientist.”

The geomorphologist communicates what he has learned about the Alps while traveling between France, Switzerland and Italy, presenting his findings to outdoor enthusiasts, local officials and schools. The transformation of mountains is very important for ski resorts, property owners, cable car operators, infrastructure planners and backpackers, he notes. For example, the town of Brienz in the Swiss Alps, east of Mont Blanc, lies in the path of a disintegrating slope formed by 42 million cubic feet of rubble. It is periodically evacuated due to rock avalanches that are getting closer and closer to it. When the experts make the decision, based on calculations of the sliding speed of the rock masses, the 80 residents of Brienz pack up their equipment and leave, as they did again this year in November 15.

Not all geomorphologists working on Ravanel’s subject (and even working closely with him) understand that scientific research is so closely linked to the well-being of recreational mountaineers like him. “We are academics and our goal is to study mountains, glaciers, seracs and moraines,” explains Philip Deline, also a geomorphologist at the University of Savoy Mont Blanc. “It is not our job to give advice to fans. “We don’t know enough to say, ‘Use this trail or that trail.'”

However, Ravanel’s message to alpine guides is to respect research that shows when and where rockfalls are most common and to constantly re-evaluate the technical capacity involved in the routes. So far they have, says Jörn Heller, a German guide who knows Ravanel and his colleagues. He is grateful for scientific research, he says, and takes it into account in his calculations. “Routes that we could take a couple of years ago at a certain time of day now have to be taken earlier,” Heller says. “In July and August, some routes, like the Couloir, are simply out of the question.”

The contributions of scientists and the caution of the guides, Heller points out, have prevented an increase in fatalities on Mont Blanc.

Ravenel’s research into ice and terrain dynamics at high altitudes is aided by his climbing skills. Recently, Ravanel accessed ice from a Mont Blanc peak that the university’s laboratories calculated to be the oldest ever found in the alpine regions: 6,250 years old.

“In this ice lies the memory of past climates,” he says. “It is now melting, which means the mountain has not had as little ice as it does now for more than 6,000 years. “That is the climate crisis.”