Tropical deforestation causes considerable heat-related mortality

Tropical deforestation causes local climate warming and is a potential risk to human health. Previous studies have shown tropical deforestation increases heat stress and reduces safe outdoor working hours, but the impact of deforestation on heat-related mortality has not been quantified. Here we make the first pan-tropical assessment of the human mortality resulting from the local climate warming caused by tropical deforestation. Analysis of satellite data shows tropical deforestation during 2001 to 2020 exposed 345 million people to local climate warming with population-weighted daytime land surface warming of 0.27°C. We estimate this warming results in 28,000 additional deaths per year. Heat-related mortality rates were greatest in Southeast Asia with 9 deaths for every 100,000 people living in deforested areas, followed by Tropical Africa (5 deaths per 100,000 people) and Tropical Central and South America (3 deaths per 100,000 people). In regions that experienced forest loss, the local climate warming from deforestation is responsible for over one third of total climate related mortality highlighting the human health risk of local warming due to tropical deforestation.