This book, through historical and forward-looking analysis carried out across various study sites by around fifty researchers and stakeholders involved in Mountain Transhumance, aims to anticipate the major changes and challenges facing this pastoral activity, in order to inform policymakers at the local, regional, national, and even global levels. The findings presented in this book are based on research conducted in the early 2020s across twenty case studies on four continents: Asia (Qilian Mountains in the northeast of the Tibetan Plateau, China; Kazakhstan; and Mount Lebanon), Africa (Green Mountains in Libya; Eastern Atlas in Algeria; High Atlas in Morocco; Tigray in northern Ethiopia; and Kamiesberg Mountains in South Africa), Americas (Canadian Rockies; Chimborazo Watershed in Ecuador; Cordillera Blanca and Altiplano in Peru; Malargüe and Southern Patagonian Andes in Argentina), and Europe (Serra da Estrela in Portugal; Cévennes and Upper Tarentaise/Alps in France; Pindos Mountains in Greece; Romania; and Scandinavian Alps in Norway). From a methodological standpoint, the research sought to combine approaches from the human and social sciences—particularly interviews and text analysis involving stakeholders recommended by local transhumance actors—with tools from life and natural sciences, such as forage balance assessments and factorial analyses. In terms of results, the research confirmed and refined the key functions of transhumance, which were found in nearly all the case studies. These functions—listed in no particular order—include: i) making use of a seasonal pastoral resource essential to the forage balance of herds, while maintaining landscapes across altitudinal gradients (one of the key ecosystem services provided by livestock farming); ii) freeing up labour for other important agricultural tasks while protecting cultivated areas from grazing; iii) strengthening food security and livelihoods for pastoral families, villages, and mountain regions; iv