Tropical deforestation is associated with considerable heat-related mortality.

Tropical deforestation induces local warming and is a potential human health risk, having been linked to elevated human heat stress and reduced safe outdoor working hours. Here we show deforestation-induced local warming is associated with 28,000 (95% confidence interval: 23,610-33,560) heat-related deaths per year using a pan-tropical assessment. Analysis of satellite data shows tropical deforestation during 2001-2020 exposed 345 million people to local warming with population-weighted daytime land surface warming of 0.27 °C. Estimated heat-related mortality rates are greatest in Southeast Asia (8-11 deaths for every 100,000 people living in deforested areas) followed by tropical regions of Africa and the Americas. In regions of forest loss, local warming from deforestation could account for over one third of total climate heat-related mortality, highlighting the important contribution of tropical deforestation to ongoing warming and heat-related health risks within the context of climate change.