Effects of climate change on high Alpine mountain environments: Evolution of mountaineering routes in the Mont Blanc massif (Western Alps) over half a century

Jacques Mourey,Mélanie Marcuzzi,Ludovic Ravanel,François Pallandre

doi:10.1080/15230430.2019.1612216

Abstract

ABSTRACTIn high alpine environments, glacial shrinkage and permafrost warming due to climate change have significant consequences on mountaineering routes. Few research projects have studied the relationship between climate change and mountaineering; this study attempts to characterize and explain the evolution over the past 40 years of the routes described in The Mont Blanc Massif: The 100 Finest Routes, Gaston Rébuffat’s emblematic guidebook, published in 1973.The main elements studied were the geomorphic and cryospheric changes at work and their impacts on the itinerary’s climbing parameters, determining the manner and possibility for an itinerary to be climbed. Thirty-one interviews, and comparison with other guidebooks, led to the identification of 25 geomorphic and cryospheric changes related to climate change that are affecting mountaineering itineraries. On average, an itinerary has been affected by nine changes. Among the 95 itineraries studied, 93 have been affected by the effects of climate change – 26 of them have been greatly affected; and three no longer exist. Moreover, periods during which these itineraries can be climbed in good conditions in summer have tended to become less predictable and periods of optimal conditions have shifted toward spring and fall, because the itineraries have become more dangerous and technically more challenging.

Highlights

Climate change led to a temperature increase of 2°C in the Alps between the end of the nineteenth century and the beginning of the twenty-first (Auer et al 2007), with a strong acceleration in warming since the 1990s (IPCC, 2014)
These people all have a good knowledge of mountaineering itineraries and 19 of them have been active in the Mont Blanc massif (MBM) since the 1980s, but only four senior alpine guides who have frequented the range since the 1970s were interviewed
The degree and type of evolution to an itinerary depends on the nature of the terrain In general, snow, ice and mixed itineraries have been more affected by climate change, with a 2.4 average level of evolution, than rock routes with a 1.6 average level of evolution

Summary

Introduction

Climate change led to a temperature increase of 2°C in the Alps between the end of the nineteenth century and the beginning of the twenty-first (Auer et al 2007), with a strong acceleration in warming since the 1990s (IPCC, 2014) In this context, and due to being very sensitive to climate variations, high alpine environments have undergone major change. The total surface area of alpine glaciers decreased by half between 1900 and 2012 (Huss 2012; Vincent et al 2017), while rock faces experienced an increase in the frequency and volume of rockfall (Geertsema et al 2006; Ravanel and Deline 2011; Ravanel et al 2013, 2017) These changes raise the question of what the effects might be on recreational mountain activities, and especially on mountaineering. This article aims to describe and explain the evolution— over nearly half a century—of mountaineering itineraries in the Mont Blanc massif (MBM), the birthplace of mountaineering and still a major mountaineering destination (Modica 2015)

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