Introduction

Droughts are a regularly occurring phenomenon in many parts of the world, and have had adverse impacts on more than a billion people in the past century (Below, Grover-Kopec, and Dilley 2007; see Table 6.1). Most migration that occurs because of drought, or as a means of mitigating the impacts of it, takes place as temporary labor migration, especially in rural populations where household livelihoods and incomes are closely tied to agricultural productivity. Extreme cases, such as distress migrations in dryland Africa of recent decades, tend to occur when the impacts of drought combine with political or economic crises, and are rarely the outcome of drought alone. Although drought-related migration originates primarily in rural areas, a number of urban centers have come perilously close to running short of water during droughts in recent years, presenting a potential future risk for which greater planning and preparation is needed. Droughts are expected to become more frequent and/or severe in many parts of the world in coming decades because of anthropogenic climate change. Recent years have seen global food prices spike in part because of droughts in key grain-exporting areas, suggesting that we are entering an era when droughts will have greater impacts on human well-being generally, even for populations not living in drought-prone areas.