The impact of climate change on migration: a synthesis of recent empirical insights

Concern about the human impact of climate change has led to predictions of how people living in areas vulnerable to drought, flood, and temperature changes will respond to such events. Early studies warned that climate change would lead to dramatic increases in human migration as households became unable to adapt to the impacts of climate change. More recently, empirical studies focused on observed climate events and trends have documented how migration flows vary as a function of both the severity of the event and the ability of the household to migrate, among other factors. In this paper, we provide a systematic review of this literature, based on a conceptual framework in which climate shocks (e.g., drought, floods, or temperature extremes) affect (a) household capability to migrate, by depleting household resources necessary for migration, and (b) household vulnerability in staying, by increasing the risk that a household falls (further) into poverty. In combination, these factors help explain four key patterns seen in the empirical literature: (1) climate-induced migration is not necessarily more prevalent among poorer households; (2) climate-induced migration tends to be more prevalent for long-distance domestic moves than local or international moves; (3) slow-onset climate changes (such as droughts) are more likely to induce increased migration than rapid-onset changes (such as floods); and (4) the severity of climate shocks impacts migration in a nonlinear fashion, with impacts influenced by whether the capability or vulnerability channel dominates.