Heavy rains and floods in East Africa that began in October have killed at least 300 people and displaced millions more. Locations in Ethiopia, Somalia and Kenya, including the giant Dadaab refugee complex in Kenya, have been hardest hit, but extreme rainfall has affected the entire region and continues.
East Africa has an annual rainy season in autumn, but this year’s catastrophic rainfall is about twice what it would have been without anthropogenic climate change, according to research released Thursday. A natural climate cycle called the Indian Ocean Dipole also contributed to heavier than usual rainfall, but this phenomenon alone does not explain the extreme amount.
Multiple isolated storms over the past two months have caused widespread flash flooding and overflowing rivers.
“The effect of climate change on rainfall can be quite large,” said Friederike Otto, a climatologist at Imperial College London and founder of World Weather Attribution, the group behind the findings.
The team took rainfall measurements from weather stations in Kenya and compared what happened in the real world with a hypothetical world without climate change, simulated by mathematical climate models.
The researchers calculated that with current climate conditions, similar extreme rainfall events would have a 2.5 percent chance of occurring in any given year. This probability finding, however, is less certain than those from World Weather Attribution’s analyzes of other events.
Part of the problem is the lack of weather and climate data. In this case, the researchers had access to robust data from Kenya, but other African countries do not have as many well-maintained weather stations.
“In Africa, everything we can say is more uncertain than in North America or Europe», said Doctor Otto.
Today’s rains follow a three-year drought, which dried out the ground and opened the way for flash floods, and which had already caused widespread crop failures, animal deaths and starvation in the region. That drought has also been exacerbated by climate change, according to a previous analysis by World Weather Attribution.
“Even if in isolated events maybe the effect of climate change is small, if more and more of these events happen, it just completely destroys people’s ability to cope,” Dr Otto said.