TNC Science Brief

Deforestation Exposes Rural People to Dangerous Heat Stress

a worker in a field
A rural worker labours under the sun in Indonesia. Photo © Nick Wolff / TNC

Tropical deforestation causes increases in local temperatures, putting human health at risk. Now, new science shows that rural Indonesians are already noting the absence of forest cooling services and changing their behavior to avoid adverse impacts from  increasing temperatures.

The Gist

Published in Global Environmental Change, the paper reveals that forested areas in East Kalimantan are up to 8.3 degrees Celsius cooler than nearby cleared areas.

Led by Ike Aggraeni from Mulawarman University, researchers collected data from more than 360 individuals across 10 rural villages in East Kalimantan, Indonesia. Those interviews revealed that workers are already noticing the increased temperatures associated with deforestation, which is impacting their ability to work.

Ninety-five percent of workers, most of whom are farmers, are altering their behavior by working less or beginning work earlier in the day. Those working in open areas, with no forest cover, are experiencing up to 6.5 hours of exposure to temperatures above accepted safe limits.

The data indicate that people who work in forests are more aware of forest cooling services, because they frequently experience the temperature difference between cleared and forested areas.

The Big Picture

Temperatures don’t vary as much in the tropics as they do in higher latitudes, so even a small increase pushes things outside of the normal range. That effect is especially concerning given that most people living in rural tropical areas make a living through subsistence farming, or other work requiring extended time outside. This work puts them at risk of heat stress or heat illness, which can weaken the immune system and exacerbate chronic illnesses over time.

Little is known about how increased temperatures will affect the health of rural populations — to date, most of the existing research on heat stress is from the developing world. “People are noticing that it’s getting hotter and it’s affecting their well-being and life choices,” says Nick Wolff, a climate change scientist at TNC and author on the research. “And in the future the impact will be even more severe.”

deforested fields
These forests in East Kalimantan, Indonesia are being cleared to make way for oil palm agriculture. Photo © Nick Hall / TNC

The Takeaway

Forests conservation is often highlighted as the key to safeguarding biodiversity and mitigating climate change. Research from another group of TNC scientists indicates that nature can provide 37 percent of the emissions reductions needed to hold global warming below 2 degrees Celsius by 2030. Reforestation, better forest management, and avoided forest conversation together contribute more than 60 percent of that nature-based mitigation potential.

But this research demonstrates that forests provide other critical services. “Reducing deforestation through better land-use planning is critical to preserve biodiversity, but it’s also critical for human health and economic productivity,” says Yuta Masuda, a sustainable development and behavioral scientist at TNC and lead author on the research.

Tropical deforestation is already affecting human health and behavior, and those effects will only worsen as the climate changes. Building on this work, the research team is analysing additional data to understand the physiological impacts of heat stress on rural workers’ cognitive performance, heat strain symptoms, and productivity.

Data collection for this research was led by Ike Aggraeni from Mulawarman University, Indonesia.

Justine E. Hausheer

Justine E. Hausheer is an award-winning science writer for The Nature Conservancy, covering the innovative research conducted by the Conservancy’s scientists in the Asia Pacific region. She has a degree from Princeton University and a master's in Science, Health, and Environmental Reporting from New York University. Justine's favorite stories take her into pristine forests, desolate deserts, or far-flung islands to report on field research as it's happening. When not writing, you can find her traipsing after birds, attempting to fish, and exploring the wild places around her home in Brisbane, Australia. More from Justine

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1 comment

  1. My TNC program, LANDFIRE, visited East Kalimantan in 2006 in order to work with local, tribal fire personnel on a plan to deal with the impacts of illegal forest burning to open areas for ag. I’m glad to see that the situation is slowly evolving. The struggles within the local communities, particularly with regard to illegal fire-setting, can be daunting.