Tropical Deforestation Exposes Millions to Deadly Heat, New Study Reveals

Tropical forests provide a crucial cooling function, shading the land, releasing water vapor, and seed clouds that reflect sunlight. However, when these forests are cleared, the ground bakes, rain clouds thin, and the risk of fire rises, leaving rural communities vulnerable to deadly heat exposure. A recent study published in Nature Climate Change has estimated that deforestation across the tropics exposes over 300 million people to higher local temperatures and is linked to 28,000 heat-related deaths each year.

Key Takeaways:

• The study found that deforestation across the tropics exposes more than 300 million people to higher local temperatures.
• In places where trees were felled, over a third of all heat-related deaths could be traced back to deforestation.
• The researchers mapped forest loss across Latin America, Africa, and Southeast Asia and compared it with land-surface warming and mortality records.
• The study's lead author, Carly Reddington, noted that vulnerable populations living near deforested regions may be disproportionately affected.
• Protecting tropical forests could save lives by maintaining cooler local temperatures and reducing the risk of deadly heat exposure.
• In Indonesia, some 48 million people live close enough to cleared forest to feel its heat.
• In the Democratic Republic of Congo, 42 million people are exposed, and in Brazil, 21 million.
• The study highlights the stark lesson that forest loss is not only a global climate threat but also a local health hazard.

Statistics:

• 300 million people are exposed to higher local temperatures due to tropical deforestation.
• 28,000 heat-related deaths occur each year due to deforestation.
• 1.7° Celsius (3° Fahrenheit) is the average temperature difference between cleared land and intact forest in Borneo.
• Oil palm plantations in Borneo have recorded extremes of 2.8-6.5°C (5-11.7°F) temperature differences.
• 48 million people in Indonesia live close enough to cleared forest to feel its heat.
• 42 million people in the Democratic Republic of Congo are exposed to deforestation.
• 21 million people in Brazil are exposed to heat from deforestation.

Sources:

• (https://www.nature.com/articles/s41558-025-02411-0) Nature Climate Change, Reddington, C.L., Smith, C., Butt, E.W. et al. Tropical deforestation is associated with considerable heat-related mortality.
• (https://news.mongabay.com/2019/04/less-rainforest-less-rain-a-cautionary-tale-from-borneo/) Mongabay, Erik Meijaard's interview in 2019.
• (https://phys.org/news/2025-08-deforestation-account-deaths-areas-tropical.html#google_vignette) Phys.org news release.