Droughts are significant drivers of land degradation, which in turn has adverse effects on resource-dependent rural populations and can potentially lead to livelihood losses and subsequent migration out of affected areas. Linkages between land degradation and migration are complex and not particularly well documented, as they occur within a larger context of multi-scale interactions of socio-economic, political, demographic, and environmental processes.

Given these uncertainties, further research in this field is needed. Here, we review existing research on how droughts affect land degradation-migration dynamics, and illustrate the pathways by which migration is affected by and responds to the climatic driver. We pay particular attention to methods used to identify, measure, and understand migration related to land degradation – including statistical approaches, application of remote sensing data and qualitative approaches – and identify common challenges encountered by researchers. We conclude by identifying future directions and priorities for research.

Why are linkages between climate change, droughts, land degradation and migration important?
Droughts, heat waves, and changes to seasonal precipitation patterns are important physical drivers of land degradation, and are expected to become more frequent and/or severe due to climate change [1,2]. This is worrisome, given that over a quarter of the Earth’s ice-free land area is already observably degraded, affecting at least 1.3 billion people, primarily in the Global South [2]. The human impacts of land degradation in low income countries include increased competition for scarce natural resources, livelihood losses, land abandonment, migration, and displacement [3•].

The specific linkages between climate change, droughts, land degradation and migration and displacement are complex and situated within wider, multi-scale interactions of environmental and non-environmental processes [3•,4]. In recent years, considerable achievements have been made in understanding the impacts of climate change on drought-related migration [5,6] but the role of land degradation (including desertification) within climate-migration processes has been understudied [2,7]. In this article we review existing scientific understanding of how droughts affect land degradation-migration dynamics (Figure 1), and describe notable methodologies used in recent research. We focus primarily on agricultural and pastoral systems in sub-Saharan Africa, although many of the key concepts and methodological approaches are relevant to similar systems on other continents, and to land degradation associated with forest clearance. We conclude by suggesting ways to move the debate forward and refer to good practice.