• Study projects 250–300 heat wave days annually in most regions by 2065–2100
• Land-use change, including deforestation, amplifies extreme heat
• Researchers urge emissions cuts and forest protection to limit impacts

Large parts of Africa could face heat waves lasting 250 to 300 days a year from 2065 onward, driven by a combination of global greenhouse gas emissions, radiation, humidity and local land-use choices, according to a study published January 7 in the scientific journal Communications Earth & Environment.

Titled “Coupled climate–land-use interactions modulate projected heatwave intensification across Africa,” the report was produced by a team of African and Western researchers. It draws on ten global climate models whose outputs were adjusted to match observed heat wave patterns, including frequency, duration, magnitude, amplitude and timing, across Africa’s nine climate regions: Mediterranean, West Africa, Central Africa, Sahara, Northern East Africa, Southern East Africa, Madagascar, Eastern Southern Africa and Western Southern Africa.

Assuming that atmospheric warming is also shaped by land-surface changes, the authors used artificial intelligence methods to quantify the role of temperature, humidity, soil moisture, wind, radiative fluxes and land use in the evolution of heat waves. The study shows that rapid land-use changes such as deforestation alter soil and atmospheric moisture, intensifying episodes of extreme heat.

The researchers examined two projection periods: mid-century (2025–2060) and late century (2065–2100), using 1979–2014 as the historical baseline.

Forests as natural air conditioners

The models show that heat waves are expected to shift from rare events to regular occurrences across all nine African climate regions. In practical terms, most regions would no longer face occasional extreme heat but sustained high temperatures for much of the year from 2065 onward.

During 2065–2100, all African climate regions except the Mediterranean and Madagascar could experience heat waves lasting 250 to 300 days annually, a five- to sevenfold increase compared with the historical period. Western Southern Africa could see the duration and frequency of heat waves rise more than twelvefold relative to the baseline.

The report stresses that the projected increase in frequency, duration and intensity will result not only from global emissions but also from local land-use decisions. In areas where intact forests cool the air and act as natural air conditioners, heat and humidity generally remain below lethal thresholds.

When forests are cleared and replaced with agricultural land, however, local climate conditions shift. Heat and moisture accumulate, surfaces warm more quickly during the day and cool less at night, effectively trapping heat. Under such conditions, a heat wave that might have been tolerable under forest cover can become prolonged and dangerous.

To reduce the intensity and duration of future heat waves and limit their socioeconomic impact, the study identifies two main levers: cutting global greenhouse gas emissions and protecting and restoring forests and natural vegetation.

Walid Kéfi