Growth Under Rising Pressure: Weather Shocks in Sub-Saharan African Cities

Sub-Saharan African cities are among the fastest growing in the world but face significant climatic risks. This study investigates how the four most important weather shocks (floods, heat waves, drought, and storms) have shaped the physical expansion of 5,721 cities in the region between 2000 and 2019. Using high-resolution remote sensing data combined with a panel of weather shocks observed over time, we find that floods, especially, reduce urban growth by 3-9%, most notably in western Africa. The effects are substantially amplified when floods follow heat waves, a common cooccurring combination. Droughts, when considered in the surrounding areas of cities, are associated with a 3% growth in urban areas. However, inverse effects are observed when treatment history is taken into account. Storms appear to accelerate the growth of wealthier towns, although the evidence is limited. Heatwaves alone show no clear effect. Our findings emphasize the need for integrated flood adaptation policies that take common co-occurring hazards equally into account. Furthermore, we emphasize the importance of considering both the historical context and the spatial dimension of the shock in empirical work.