As one of the highest and most prominent mountains in Europe, Mont Blanc is a very popular mountain to climb among mountaineers all over the world. However, this venture has become increasingly challenging, as many of the routes have undergone significant changes, and in some cases disappeared completely.

As climate change causes an increasing level of physical alterations to routes on Mont Blanc, it is taking its toll on mountaineering in the region. However, the new conditions climbers encounter on the mountain are still widely unknown and barely researched, particularly in the western Alps. A new study published in the journal Arctic, Antarctic, and Alpine Research attempts to go some way towards addressing this, working closely with mountaineers to investigate their perception of and adaptation methods to the changing conditions.

The research attempts to chart the evolution of 95 of the routes described in Gaston Rébuffat’s 1973 guidebook The Mont Blanc Massif: The 100 Finest Routes, which – in addition to its popularity among mountaineers – includes a wide range of route difficulty levels and typology (snow, rocks, and mixed routes).


As the lead author, Jacques Mourey, explains, this study has achieved multiple contributions to the mountaineering community. For example, by identifying an average of nine geomorphic, climate-related changes on every route, mountaineers and climbers are now able to plan and prepare for these previously unknown elements and, where possible, adapt their practices to address them.

The researchers also investigated and evaluated the modification level for each route. “One third of the routes studied have greatly evolved, which means they can no longer be climbed in summer,” says Mourey. “Objective dangers and technical difficulty have greatly increased due to the number and intensity of the geomorphic changes affecting them.” Mountaineers can therefore no longer rely on guidebooks written several years ago; instead, they have to fundamentally change the manner in which they climb their chosen route. In three cases of the 95 investigated routes, the changes have been so drastic that they can no longer be climbed at all – due to their disappearance.

According to Mourey, perhaps the most significant impact this study can have is the development of a specific prevention campaign, using the results. This campaign would target the mountaineering community and raise awareness of the effects of climate change in their sport. “Mountaineering routes tend to have become more technically difficult and more dangerous. Optimal periods during summer months have become increasingly rare and unpredictable.”

Mountaineering changes worldwide

Following the conclusion of his study, Mourey was confronted with several questions concerning the mountaineering conditions on a global scale. A research gap continues to exist among different mountain ranges, especially high elevation mountain ranges, such as the Andes or the Himalaya.  There is no data as yet which determines how much these regions and their routes are affected by climate-related changes, and whether the optimal climbing season has been modified. Mourey is especially interested in the comparison to the Alps: Are the geomorphic changes the same all across the world? And how are mountaineers adapting to them?

In order to investigate some of these questions, Mourey conducted a follow-up study and will be presenting its results at the International Mountain Conference 2019 in September, hosted in Innsbruck.

Although extensive, Mourey is aware of the limits of his research. While identifying and listing the affected areas of the routes and the changes, he and his team did not keep a record of their localizations. The ideal research would be a basis for a map which locates and keeps record of all the processes affecting the routes. “This would be a very useful tool, leading to a more precise analysis and more visual results, especially for the prevention campaign.”

And although enjoying his field work, Mourey leaves us with a word of warning: “It was fascinating but also disturbing to see how fast high mountain environments in the Alps are changing due to climate change.”

Read More:

Mourey, Jacques & Marcuzzi, Mélanie, Ravanel, Ludovic & Pallandre, François. 'Effects of climate change on high Alpine mountain environments: Evolution of mountaineering routes in the Mont Blanc massif (Western Alps) over half a century.' Arctic Antarctic and Alpine Research. 51. 176-189. (2019):

Newsletter subscription