The East Africa region, encompassing Tanzania, Kenya, and Burundi, has recently experienced heavy rainfall and devastating floods, which have been attributed to human-induced climate change. An international team of leading scientists from the World Weather Attribution group has identified climate change as a key driver of the severity of these events in cities and urbanizing areas.
To determine the role of human-induced climate change, researchers assessed whether there are increased or decreased precipitation trends in the region during the long rains in climate models. Although the trends are not statistically significant, they indicate a tendency towards increased rainfall.
Scientists suggest that these extreme weather events are likely to become more frequent, potentially occurring twice as often and being 5% more intense in today’s climate, which reflects the effects of 1.2°C of global warming. Projections for a climate of 2°C warmer than preindustrial times suggest that both the intensity and likelihood of heavy rainfall will further increase.
East African cities face significant pressure from changing climate risks, as climate models predict continued heavy rainfall in the region with further warming. The study focused on the maximum 30-day rainfall during the long rains from March to May, particularly in southern Kenya, most of Tanzania, and areas around Lake Tanganyika in Burundi, where the impacts were most severe. The resulting devastation has included loss of lives, livestock, and up to 27,000 acres of land as well as property destroyed.
Weather observations across the region indicate that the amount of rainfall during the long rains decreased from the mid-1990s until 2008. However, over the past 15 years, the March-May period has shown a trend of increasing rainfall.
Joyce Kimutai, a researcher at the Grantham Institute – Climate Change and the Environment, Imperial College London, echoes these findings. She notes that historical weather observations have shown a drying trend in the region, but recent climate models project heavy rainfall with climate change.
“In recent years, there appears to be a shift, as new climate models reflect the changing behavior of the long rains with global warming,” Kimutai said.
“The most recent weather observations and latest climate models agree that the long rains bring more rain each year, and with further warming, they will become even more intense and dangerous. We must prepare for this new reality and stop burning fossil fuels to avoid worsening an already dire situation.”
