Why Deforestation Is Causing Heat Deaths to Soar

[LIMA, SciDev.Net] Halting deforestation is not just an environmental issue but also a public health imperative, say researchers after a study found compelling evidence on the rise in heat deaths linked to tree loss.

The study published in Nature Climate Change combined satellite data on tree cover loss with temperature and mortality models to reveal the human cost of forest loss across tropical regions.

It found that, between 2001 and 2020, 345 million people globally were exposed to localised warming that was directly linked to deforestation, due mainly to the loss of the cooling mechanism provided by tree cover.

Agriculture, logging, mining, and other activities have converted vast areas of forest, contributing to substantial local temperature increases.

Carly Reddington, research fellow, School of Earth and Environment, Leeds University

This was found to have led to around 28,000 heat-related deaths a year, mainly across Africa, Southeast Asia, and Latin America.

The researchers say the findings highlight an urgent public health challenge for tropical regions, with indigenous communities heavily affected.

Carly Reddington, the study’s author, told SciDev.Net: “As climate change intensifies, extreme heat will become more frequent and severe, particularly in deforested areas that lack the cooling benefits of trees.

“We have already seen episodes of extreme heat and prolonged drought in places like the Brazilian Amazon in recent years.”

South and Central America is the region with the greatest deforestation in the tropics, with an area the size of Turkey lost during the study period (around 760,000 km2 in Latin America compared to 490,000 km2 in Southeast Asia and 340,000 km2 in Africa).

Latin America also recorded the largest deforestation-induced temperature increase, at 0.53 degrees Celsius, compared to 0.39 in Africa and 0.37 in Southeast Asia.

‘Troubling situation’

“The figures from Central and South America show a troubling situation,” said Reddington, who is a research fellow at the School of Earth and Environment of Leeds University, in northern England.

“Agriculture, logging, mining, and other activities have converted vast areas of forest, contributing to substantial local temperature increases.”

The study reveals that forest loss accounts for nearly 70 per cent of the observed warming in deforested areas of Latin America.

“This means that deforestation is a major driver of heat in the region — more so than global climate change alone,” added Reddington.

In general, the regions with the greatest deforestation-induced warming correspond to those with the greatest forest loss, particularly in the so-called “Arc of Deforestation” in the southern Amazon, and Sumatra and Kalimantan in Indonesia, according to the authors.

However, although Latin America has the greatest localised warming associated with deforestation, it also has the lowest population exposed to the effects of temperature increases. For Latin America the figure is 67 million, compared to 148 million in Africa and 122 million in Southeast Asia.

This, the authors explain, is because fewer people live in rural areas of Latin America compared to other tropical regions.

Vulnerable communities

Reddington cautions that the lower numbers in Latin America do not mean that the health risks are low. “Many communities in these regions — particularly low-income, rural, traditional, or indigenous populations — may face much higher heat-related health risks,” she said.

David Rojas, an environmental epidemiologist at Lancet Countdown South America who was not involved in the research, told SciDev.Net that an important factor to consider is the living conditions of people near deforested areas.

“It’s true that in more rural areas, where there is still a lot of nature, the population exposed to these conditions is smaller,” Rojas said.

“But many of these populations live in extreme social, food, and sometimes occupational deprivation, as well as deprivation of access to sanitation and drinking water services, which are major determinants of health.”

Governments worldwide have pledged to halt forest loss by 2030, but there is a lack of information — such as maps showing reforestation — to track these efforts, according to the World Resources Institute.

Rojas hopes the study will encourage governments to rethink production models that drive forest loss and accelerate action to avert deforestation.

For Reddington, policy priorities should be not only halting deforestation and expanding protected forest areas, but also supporting local communities with climate adaptation measures and including health impacts in climate change mitigation and land-use plans.

She added: “Ultimately, reducing deforestation can help slow local warming, protect ecosystems, and save lives — making it a win-win for people and the planet.”

This article was produced by SciDev.Net ‘s Latin America and Caribbean desk.

You might also like

[related-articles]