Tropical Peat Fires Reach Highest Level in 2,000 Years

Tropical peatland fires have reached their highest levels in at least 2,000 years, according to a new study published in March 2026 in the journal Global Change Biology.

The study, titled “Unprecedented Burning in Tropical Peatlands During the 20th Century Compared to the Previous Two Millennia,” reveals a sharp increase in peat fires during the 20th century—marking a shift away from natural climate-driven patterns toward human-caused impacts.

Led by Yuwan Wang of the University of Exeter, the international research team analyzed charcoal records preserved in peat sediments across tropical regions worldwide.

“We found that peatland fire activity increased dramatically during the 20th century, far exceeding natural variability over the past two millennia,” Wang said in a statement accompanying the study.

How Scientists Reconstructed 2,000 Years of Peat Fire History

To understand long-term fire patterns, researchers compiled and analyzed 58 charcoal records from peatlands in South America, Africa, Southeast Asia and Australasia.

Charcoal fragments trapped in peat layers act as natural archives, allowing scientists to reconstruct fire activity over thousands of years.

The findings show that, for most of history, peat fires were largely controlled by climate factors, particularly temperature and drought intensity.

Between 0 and around 850 CE, fire activity was relatively high. However, it gradually declined and remained stable for more than a millennium, closely tracking natural climate variability.

Why Peat Fires Surged in the 20th Century

That long-standing pattern changed abruptly in the 20th century.

The study identifies a sharp and unprecedented rise in peatland fires that cannot be explained by climate alone. Instead, regional differences point to human activity as the dominant driver.

The most significant increases were observed in Southeast Asia and Australasia—regions that have undergone rapid land-use changes in recent decades.

Peatland drainage for agriculture, deforestation and large-scale land conversion have significantly altered these ecosystems, making them more vulnerable to fire.

Once drained, peat dries out and becomes highly flammable—even small ignition sources can trigger long-lasting underground fires.

In contrast, peatlands in South America and Africa—where ecosystems remain relatively intact—did not show the same increase in fire activity.

However, Wang warned that these regions could face similar risks in the future as development pressures grow.

A Major Threat to the Global Climate

Peatlands play a critical role in regulating the Earth’s climate. Although they cover only a small portion of the land surface, they store vast amounts of carbon accumulated over thousands of years.

When peat burns, that stored carbon is rapidly released into the atmosphere, accelerating global warming.

The impacts extend beyond climate change, contributing to severe air pollution and posing serious health risks to nearby populations.

“To avoid massive carbon emissions that worsen climate change, we must urgently protect these carbon-rich ecosystems,” Wang said.

Researchers emphasize that reducing peat fires will require a combination of conservation, sustainable land management and large-scale ecosystem restoration.

Southeast Asia Emerges as a Global Hotspot

The study highlights Southeast Asia as the global epicenter of rising peat fire activity.

The region, including Indonesia, contains some of the largest tropical peatland areas in the world—but also some of the most degraded.

Peat forms from partially decomposed plant material in waterlogged, oxygen-poor conditions. In its natural state, it acts as both a carbon sink and a water reservoir.

However, when drained through canals for agriculture or plantations, peat loses its moisture, becomes unstable and highly flammable, and is extremely difficult to extinguish once ignited.

Indonesia: Recurring Fires and Emerging Risks in Papua

In Indonesia, peatland fires have become a recurring environmental crisis, particularly in Sumatra and Kalimantan.

Major fire events, such as those in 2015, triggered transboundary haze that affected millions of people across Southeast Asia, causing widespread health problems and significant economic losses.

These fires are closely linked to land clearing practices that involve draining peatlands on a large scale.

Concerns are now growing in eastern Indonesia, particularly in Papua, where large-scale agricultural development—often referred to as food estate projects—is being planned.

If such projects involve peatland drainage and land conversion, they could significantly increase fire risks in a region that remains relatively intact.

Previous studies have shown that Papua’s peatlands are still largely undisturbed and serve as important carbon sinks. Their degradation could have far-reaching consequences not only locally, but also for the global climate. (Sulung Prasetyo)