Warming increases the risk of civil war in Africa

Abstract

Armed conflict within nations has had disastrous humanitarian consequences throughout much of the world. Here we undertake the first comprehensive examination of the potential impact of global climate change on armed conflict in sub-Saharan Africa. We find strong historical linkages between civil war and temperature in Africa, with warmer years leading to significant increases in the likelihood of war. When combined with climate model projections of future temperature trends, this historical response to temperature suggests a roughly 54% increase in armed conflict incidence by 2030, or an additional 393,000 battle deaths if future wars are as deadly as recent wars. Our results suggest an urgent need to reform African governments' and foreign aid donors' policies to deal with rising temperatures.

Fig. 1.

Projected changes in climate and conflict to 2030. (Left) Projected changes in climate to 2030 for 5 sub-Saharan Africa subregions and the region as a whole. Boxplots show the range of model ensemble projected changes for precipitation (% change, Top) and temperature (°C, Bottom), for 2020–2039 minus 1980–1999, based on the 18 models running the A1B scenario, with the dark vertical line representing the median, the colored boxes showing the interquartile range, and the whiskers indicating the extremes. (Right) Projected percentage point change in the incidence of civil war for the same period and regions, based the same climate model projections and a 10,000-run bootstrap of model 1 in Table 1. For each region, boxplot 1 represents projections including uncertainty in both climate model projections and in conflict response to climate, boxplot 2 represents uncertainty only in conflict response to climate, and boxplot 3 represents uncertainty only in climate projections. Dark vertical lines represent median projection, colored boxes show the interquartile range, and whiskers indicate the 5th–95th percentile of projections.

Fig. 2.

Projected percent changes in the incidence of civil war for all of sub-Saharan Africa, including both climate and conflict uncertainty as calculated as in Fig. 1. (Top) Projections based on alternative specifications of the relationship between climate and conflict, with other factors fixed. (Bottom) Projected combined effects of changes in climate, per capita income, and democracy. Dark vertical lines represent the median projection, colored boxes show the interquartile range, and whiskers indicate the 5th–95th percentile of projections, using climate projections from all climate models for the A1B scenario, such that each boxplot represents 180,000 projections. Each specification includes the variables listed on the left (contemporaneous and lagged for the climate variables) in addition to country time trends and country fixed effects.