Climatic Stress, Internal Migration, and Syrian Civil War Onset

Syria recently suffered a once in 500-year meteorological drought followed by one of the worst conflicts of the twenty-first century. We exploit subnational variation in drought impact to examine associations between climatic stress and Syria’s political unrest. Climatic stress may produce instability through both immediate hardship and, indirectly, internal migration. Consistent with the internal migration hypothesis, we find less severely drought-stricken Syrian regions more likely to experience protest. We employ nighttime lights as a proxy for population density to examine the association between climatic stress and internal displacement. We find climatic stress decreased nighttime light intensity during the drought period. Increases in nighttime lights from 2005 to 2010 are associated with added risk of protest in Sunni Arab areas, suggesting an influx of migrants bolstered local grievances. Our findings support the internal migration hypothesis and suggest extreme climate events may impact civil unrest via geographically and temporally indirect paths.