Climate Models Predict Severe Impacts for Parts of Africa

Africa Faces Increasingly Permanent Heatwaves

Climate change is causing a shift in weather patterns across Africa, where heatwaves are transitioning from temporary events to a more permanent part of the climate. Research indicates a rapid rise in Africa’s exposure to dangerous heat levels, presenting a significant challenge.

Understanding Heat in Africa’s Diverse Climates

Estimating the severity of this rising heat has been difficult due to limitations in global climate models that often fail to capture the local factors shaping heat in Africa’s varied climate zones, including humid tropics, dry savannas, and agricultural areas. Analyzing these local factors is crucial, as changes in land use, such as deforestation, alter soil moisture and humidity, contributing to extreme heat.

Projecting Future Heatwave Risk

A team of hydroclimate and land-atmosphere scientists developed a framework to produce reliable, locally relevant projections of future heatwaves. This approach considered both the warming atmosphere and the impact of land transformation. The framework was built on four pillars: utilizing data from 10 global climate models, adjusting model outputs to match observed heatwave patterns, employing artificial intelligence (AI) to quantify the impact of various heat drivers, and comparing scenarios with high and reduced carbon emissions.

Projected Heatwave Frequency

Research indicates that by the late 21st century, most regions in Africa will experience extreme heat for the majority of the year, moving away from occasional heatwaves. By 2065-2100, many parts of Africa (excluding Madagascar) could face heatwaves lasting 250-300 days per year. Some areas in western southern Africa are projected to experience heatwaves 12 times longer and more frequent, even with emissions reductions, potentially lasting over 40 days.

The Impact of Land Use

Forests act as natural air-conditioners, preventing fatal heat. However, when forests are replaced with cropland, the local climate changes. Crops release moisture, increasing humidity and creating a heat trap. This rising background heat affects entire regions, particularly impacting rural communities and informal settlements lacking shade and cooling infrastructure.

Reaching a ‘Deadly Threshold’

Modeling reveals a specific combination of heat and humidity that can rapidly intensify heatwaves, particularly in areas dominated by cropland. This is a crop-driven humidity effect that pushes the atmosphere into a danger zone. For example, in west Africa, extreme heat will peak at about 26.5°C-26.8°C with 74%-75% humidity, producing heatwaves that last 30-35 days. In southern east Africa, heatwaves will occur even at lower temperatures (23.6°C-23.8°C) and humidity (70%-72%), with small increases in heat or moisture exacerbating the problem.

A Regular Part of the Year

Across all nine African climate regions, research found that heatwaves will become a regular occurrence, no longer rare events. Fortunately, local land choices can offer immediate protection. Protecting and restoring vegetation, and utilizing climate-smart farming practices, are public health defenses that can weaken the intensity and duration of heatwaves.

What Needs to Happen Next

Protecting the continent requires action on two fronts. Globally, reducing fossil fuel emissions is crucial to lower the risk of prolonged heatwaves. Locally, land-clearing decisions matter significantly; removing natural vegetation adds heat, while preserving forests and vegetation helps regulate temperatures. Countries cannot control global warming alone, but they can manage how the land responds to it.