The study, which used large-ensemble climate models to examine trends across the continent, links these changes primarily to greenhouse gas and black carbon emissions from fossil fuel use.
The researchers compared heat wave trends between two time periods: 1950–1979 and 1985–2014. The results showed that while the earlier period experienced infrequent and relatively weak heat waves, the later decades saw events occurring up to every two years and lasting three times longer on average.
The study highlights the specific vulnerability of African nations to extreme heat, due in part to limited adaptive infrastructure and insufficient meteorological data. In countries where early-warning systems and cooling infrastructure are often lacking, heat waves pose direct threats to public health, agricultural productivity and energy systems.
During one particularly extreme event in April 2024, the West African city of Kayes recorded temperatures exceeding 119 °F (48 °C). Similar events strain already overburdened power grids and reduce crop yields. Populations such as infants, older adults and those with chronic conditions are especially susceptible to heat-related illness.
Using computer model simulations from the Community Earth System Model 2—Large Ensemble, the researchers were able to isolate the factors contributing to daytime, nighttime and compound heat waves, including human-driven influences like greenhouse gas and aerosol emissions as well as natural variability.
In the earlier period, natural variability explained most of the observed activity, but by 1985–2014, only 30% of heat wave events were attributed to natural causes.
The team also notes that sulfate aerosols – a type of airborne particle produced naturally by volcanic activity and through fossil fuel combustion – once played a cooling role in the earlier decades by making clouds reflect more light back into space. However, their relative influence has diminished over time.
In the more recent data, greenhouse gas and black carbon emissions – linked to incomplete combustion of fuels – emerged as a strong contributor to increased heat wave intensity and frequency.
The study also found that rising near-surface air temperatures closely correlate with heat wave frequency, suggesting shared underlying drivers such as changes in air circulation and energy balance at the land surface.
Notably, these trends were not isolated to specific countries or regions. Instead, consistent increases in heat wave activity were observed across North, West, East, Central and Southern Africa.
Looking ahead, the researchers plan to assess how global mitigation strategies, including those proposed under the Paris Agreement, might influence future heat wave patterns in Africa.
While Africa contributes a relatively small share of global greenhouse gas emissions, climate change is a global issue that is intensifying heat waves everywhere. Addressing this requires global cooperation to aggressively reduce emissions and build adaptive capacity.
A Guest Editorial