Mapping climate-change-related processes affecting most frequented routes by French mountain guides

Abstract. This paper examines the impact of climate change on alpinism in the western European Alps, focusing particularly on the routes most frequently used by French mountain guides. The aim is to identify the geomorphological and glaciological processes affecting these routes and to evaluate how these changes impact guiding practices. Two complementary approaches were employed. First, a survey of the French Mountain Guides Association (SNGM) was conducted to identify the 24 most frequented routes used by French mountain guides between 2017 and 2022. Semi-structured interviews were then conducted with guides and hut keepers to recognise 24 climate-related processes, which were then compared with the iconic itineraries detailed in Gaston Rébuffat's classic guidebooks. The analysis shows that the most frequented routes are affected by an average of seven glaciological or geomorphological processes, compared to nine for the historic routes. Itineraries involving high-altitude and mixed terrain are particularly exposed to glacier retreat, permafrost degradation and rockfalls. In response, guides are adopting various strategies, such as abandoning the most dangerous routes, choosing safer alternatives and scheduling ascents for spring or autumn. They are also temporarily suspending climbing some routes during heat waves. These adaptations illustrate the emergence of a culture of adaptation to climate change within the guiding profession. However, the discussion also highlights persistent tensions. While high-altitude alpinism remains central to the cultural identity of guides, it is also becoming increasingly risky. Meanwhile, the shift towards mid-altitude routes is creating conflicts with other land users and raising ecological issues. The long-term sustainability of these adaptations is unclear, particularly in light of the hardly predictable effects of cryosphere evolution. French mountain guides are at the forefront of this transition through mobility and innovation. Supporting their adaptive strategies is crucial to preserving both the safety of high-altitude guiding and its cultural significance.