International audienceClimate change is having a major impact on high mountain areas, with glacier retreat and permafrost warming. Alpinism is deeply affected by this changing environment, which increases the technicality of the routes, their dangers, and the uncertainty of the periods of suitable climbing conditions during the summer. This raises the question of how recreational alpinists perceive and adapt to changing conditions. To answer this question, this paper reports the results of a quantitative social media survey of European alpinists based on the substitutability theory. The results from the 1071 completed questionnaires show that climate change and its impacts are clearly observed and identified by recreational alpinists; the h...