The devastating drought in the Horn of Africa “would not have occurred without climate change” as global warming made such exceptionally dry conditions in the region about 100 times more likely, scientists have concluded.
The severe agricultural drought that has gripped swaths of east Africa since 2021, the worst in four decades, has led to widespread crop failures, animal deaths and left more than 4mn people in need of humanitarian assistance and 20mn at risk of food insecurity.
In the absence of human-driven climate change, the agricultural drought in southern Ethiopia, southern Somalia and eastern Kenya would not have occurred, the World Weather Attribution group concluded on Thursday.
The independent international collaboration draws on academics and scientists from around the world to assess whether the effects of climate change can be linked to extreme weather events.
The intensity and likelihood of the African drought was “mostly” because of the evaporation of water from soil and plants, which had “significantly” increased as a result of higher than normal temperatures, they said.
“Frequent multi-years droughts . . . will severely impact food security and human health in the Horn of Africa as the climate continues to warm,” said Joyce Kimutai, a climate scientist at the Kenya Meteorological Department and an author of the study.
While people living in the region were “no strangers to drought”, the duration of this one “stretched people beyond their ability to cope”, said Cheikh Kane, climate resilience policy adviser at the Red Cross Red Crescent Climate Centre and a report author.
Extreme weather events will become more likely and intense with every fraction of a degree of warming, scientists have warned.
The researchers for the latest study analysed weather data and computer model simulations to compare today’s climate with what would have happened in the pre-industrial era, before the world had warmed by an estimated 1.1C.
Despite recent heavy rain and flash flooding in the Horn of Africa, Nasa’s Earth Observatory warned in March that drought conditions were “likely to continue”, and that this year’s wet weather “doesn’t just undo three years of drought”.
Over the longer term, the March to May wet season in the region, when most of the yearly rainfall occurs, was becoming dryer because of climate change, although precipitation between October and December was increasing, the report said.
However, both seasons were marked by below average rainfall in 2021 and 2022, in part as a result of the La Nina weather phenomenon, that has unusually persisted for the past three years and is associated with less rain in the region towards the end of last year.
Without the effect of climate change on temperatures, conditions would have been “abnormally dry”, meaning that human-driven warming “was a necessary factor for the current drought to occur”, the 19 authors of the study found.
Climate change had “played a big role” but the strife of food insecurity was “to a very large degree driven by vulnerability and exposure, and not just by the weather events”, noted Friederike Otto, an author of the study and senior lecturer in climate science at Imperial College London.
“There are a lot of other factors that drive how the drought can turn into a disaster like this,” she added.
