Abstract.The relationship between migration and environmental and climatic changes is a crucial yet understudied factor influencing mountain livelihoods in the global South. These livelihoods are often characterized by high prevalence of family farming, widespread dependence on natural resources, and high sensitivity to climatic changes. Except for a limited number of empirical case studies, the literature on migration and global environmental change has not yet moved beyond case study results to address and explain global patterns and specificities of migration in mountain areas of the global South. After an introduction to the topic, the authors present a new synthesis of three field studies combining household surveys, participatory research approach (PRA) tools and key informant interviews in Pakistan, Peru, and Tanzania. This article suggests that the systematic use of transdisciplinary approaches, with a combination of quantitative and qualitative empirical methods, is the key to understanding global migration patterns in rural mountain areas of the global South. The results of our synthesis suggests that survey data should be triangulated with PRA results as well as secondary data in order to build household profiles connecting vulnerability (measured through a multidimensional index) with human mobility patterns. Such profiles can be conducive to better understand the feedback processes between livelihoods and mobility patterns both within each case study and across case studies, helping researchers to draw general lessons.