Summary/Abstract
Between March and May of 2024 a series of heavy rainfall events in East Africa caused significant flooding in Kenya and Tanzania. In this peer-reviewed event study, the authors assess the impact of climate change, along with several compounding factors, on these events.
Climatological event studies are complicated in East Africa by a long-standing trend, sometimes referred to as the “East Africa Paradox,” in which model projections suggested a drying trend in the region, but observations actually showed a wettening trend. This divergence was particularly pronounced from the mid-1990s to the first decade of 21st century. The authors conclude that, without a full understanding and statistical model of the mechanisms behind this regional climate phenomenon, “it is not currently possible to isolate and identify the effect of climate change on the accumulated rainfall in this region.” However, the authors also assess whether there are wettening or drying trends in the region for the long rains in climate models, and identify a trend of increased wettening, and accompaning increases in rainfall intensity and likelihood, as the climate warms.
The authors also discuss the impact of several confounding social, economic, and political factors on flood risk in the region. The authors note that flood risk in East Africa has been compounded by land management practices that have led to agricultural expansion and deforestation, and that flood resilience in urban areas is undermined by “unplanned growth” which has resulted in vulnerable informal settlements lacking adequate infrastructure near urban cores.