From a new paper by Cullen Hendrix and Idean Solehyan:
This paper examines the relationship between rainfall, water, and socio-political unrest in Africa. In particular, we are interested in how deviations from normal rainfall patterns, and extreme events such as flooding and drought, affect the propensity for individuals and groups to engage in disruptive activities such as demonstrations, riots, strikes, communal conflict, and anti-government violence. In contrast to much of the environmental security literature, we use a much broader definition of conflict that includes, but is not is not limited to, organized rebellion. Using a new database of over 6,000 instances of social conflict in the past 20 years - the Social Conflict in Africa Database (SCAD) - we examine the effect of deviations from normal rainfall patterns on various types of conflict. Our results indicate that rainfall variability has a significant effect on both large-scale and smaller-scale instances of political conflict. We find that rainfall is correlated with civil war and insurgency, although wetter years are more likely to suffer from violent events. Extreme deviations in rainfall - particularly dry and wet years - are associated with all types of political conflict (violent and nonviolent, government-targeted and non/government-targeted), though the relationship is strongest with respect to violent events, which are more responsive to abundant rather than scarce rainfall. By looking at a broader spectrum of social conflict, rather than limiting the analysis to civil war, we demonstrate a robust relationship between environmental shocks and violence.
This is part of a growing body of research on how natural disasters and environmental changes affect politics. A recent article by Alastair Smith and Alejandro Quiroz Flores looked at how democracies perform relative to autocracies in mitigating the effects of disasters, and of course Amartya Sen famously showed that the worst famine in Indian history was a result of poor government response to a drought. (Johann Hari argues that this was at least partially Winston Churchill's fault.) Keep this in mind when reading about the ongoing flooding in Pakistan, the the fires in Russia, and the Chinese mudslides.