drought in Ethiopia

Major drought in the Horn of Africa ‘100 times more likely’ due to climate change

Image credit: reuters

Recent extended droughts in the Horn of Africa that left 4.35 million people in need of humanitarian assistance would not have occurred without climate change, a study has found.

Since October 2020, large parts of Eastern Africa have been experiencing extended dry conditions followed by short intense rainfall events that often led to flash floods.

The drought has led to substantial harvest failure, poor pasture conditions, livestock losses, decreased surface water availability and human conflicts.

The below-average rainfall seen in the final quarter of 2022 continued a pattern that had been recurring since 2020.

A group of international climate scientists with World Weather Attribution (WWA) collaborated to assess to what extent human-induced climate change altered the likelihood and intensity of the low rainfall that led to drought, as well as the increase in evaporation due to climate change.

The team analysed rainfall over the most impacted region - covering parts of southern Ethiopia, southern Somalia and eastern Kenya - for 24 consecutive months from January 2021 to December 2022, as well as the 2022 March-May and October-December seasons separately.

In the current climate, which has been warmed by approximately 1.2°C by human-induced greenhouse gas emissions, the below-average rainfall in the March-May season is a one in 10-year event. For the entire 24-month period, there is a 5 per cent chance in every year for such an event to develop.

The researchers found that there is a trend towards less rainfall in the long rains but not over the short rains, which displayed the opposite. Using climate models, they determined that low rainfall events, like those currently observed in the long rains, have become about twice as likely due to human-induced climate change, while a low rainfall season in the short rains has become less likely, also attributed to climate change.

"Climate change has made this drought exceptional," said Joyce Kimutai, a climate scientist with the Kenya Meteorological Department who worked with WWA.

The team found that in a world 1.2°C cooler, the drought likely would not have occurred at all, but that under current rates of warming droughts such as this one have become about 100 times more likely.

The researchers said that the regional climate variability and the projections indicate the need to invest in “adaptation strategies” that are robust to both wet and dry extremes. These strategies can be iterated over time as future climate projections become more certain.

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