Summary/Abstract
At the end of March and the beginning of April 2024, a very large region across North Africa and the Sahel experienced extreme heat, with maximum temperatures in the Sahel reaching 45 C and more and minimum temperatures of 32 C in Burkina Faso. This heatwave coincided with Ramadan (fasting) and power cuts, which compounded the risk for vulnerable groups and even those not traditionally considered vulnerable.
To estimate the influence of human-caused climate change on extreme heat, this real-time event attribution study combines climate models with observations. The study finds that, even considering the 1.2°C increase in global temperatures since pre-industrial times due to human activities, the extreme heat observed over the Mali/Burkina Faso region is still rare. While the daily temperatures were extreme, with a return time of about 100 years, the authors find that the 5-day maximum temperatures were particularly unusual, with a return time of 200 years. The authors further found that minimum temperatures were less extreme but still rare, with a return time of 20 years over Mali/Burkina Faso and 30 years for the Sahel region.
The authors note that both observations and climate models show that heatwaves with the magnitude observed in March and April 2024 in the region could not have occurred without the global warming of 1.2°C to date. In the absence of anthropogenic climate change, a comparably rare extreme 5-day maximum heat event would have been 1.5 °C cooler over Mali/Burkina Faso, and 1.4 °C cooler over the larger Sahel region. Using forward-looking climate models, the authors additionally find that, over Mali/Burkina Faso, a heatwave like the observed event would be another 1°C hotter in a 0.8°C warmer world (2°C total global warming). Under such conditions, the authors calculate that an event of the same magnitude as that which was observed in 2024 would occur 10 times more frequently than in today’s climate.