Millions of Kenyans and Ugandans will experience extreme heat stress later this century as a result of climate change, a new US scientific study warns.
“People living in already warm climates will have to endure increasingly intolerable conditions,” said Salvi Asefi-Najafabady, a University of Virginia researcher who led the study.
Living conditions for hundreds of millions of East Africans will become “unbearable” in coming decades, Mr Asefi-Najafabady added.
His team of scientists used sophisticated earth-system computer models to predict the impact of climate change by taking account of projected shifts in land use and population patterns as well as atmospheric conditions.
“Earth system models give us a sense for the scope and magnitude of the problems we face,” University of Virginia ecologist Deborah Lawrence said.
“We looked at where heat stress will occur and compared it with where people are likely to be.”
More than 70 million Kenyans and Ugandans currently experience 20 to 25 days of dangerous heat per year, Ms Lawrence noted.
"In 2090, it could be more than 125 days, with far more people at risk.”
The study charts expected increases in “heat stress” in nine countries in Africa's Great Lakes region, with the most severe outcomes likely in western Kenya, Uganda and parts of the Democratic Republic of Congo.
“Heat stress,” which takes account of relative humidity and wind speed as well as temperature, provides a more realistic assessment of human discomfort than do mercury readings alone, the researchers said.
Densely populated and economically insecure parts of Kenya and Uganda will feel heat stress most acutely, suggests the study, which is published in the scholarly journal Climatic Change.
The researchers emphasised the need to begin immediately in planning for adaptation to climate change in East Africa.
“In this dismal message lies an opportunity for clear communication about the absolute necessity for meaningful action on climate change in the present,” said Anton Seimon, a climate scientist at Appalachian State University and a member of the team that compiled the study.