In the study, which was published on Aug. 27 in Nature Climate Change, researchers examined satellite images on tropical forests across Central and South America, Africa and Southeast Asia taken between 2001 and 2020 to measure the temperature changes. The study also analyzed how much the heating was caused by deforestation.

The study found that deforestation had exposed over 300 million people worldwide to hotter temperatures, with the phenomenon also associated with 28,000 heat-related deaths each year in those areas.

When a plot of land is deforested, it loses trees that naturally regulate the climate through shade, moisture release and carbon dioxide absorption. Without these natural cooling mechanisms, local heating amplifies, leading to various illnesses and even death for people living near the former forest area.

Indonesia, home to many of the last few remaining tropical rainforests globally, had the highest mortality rate among other countries in the study. Researchers estimated up to 6,730 deaths per year due to illnesses associated with rising temperatures in and near deforested areas across the country.

The rapid deforestation in Indonesia, combined with relatively high heat vulnerability among Southeast Asian populations, contributed to the high rate observed in Indonesia, said Carly Reddington, research fellow at University of Leeds’ Institute for Climate and Atmospheric Science, in the United Kingdom, who coled the study.

Read also: Deforestation climbed to 175,000 ha in 2024, ministry admits