Behind the Haze of Indonesia’s Land and Forest Fires

This gap in information prompted The Nature Conservancy’s Indonesia affiliate, Yayasan Konservasi Alam Nusantara (YKAN), together with the National Research and Innovation Agency and Tanjungpura University, to conduct a prescribed peatland burning experiment in Singkawang, West Kalimantan. The region was selected because it is prone to forest and land fires, particularly in peatland ecosystems, and because local communities here have a longstanding tradition of using fire to clear land for cultivation.

Our goal is to generate empirical data that can improve the accuracy of peat fire emission calculations.

Indonesia is home to one of the largest tropical peatland ecosystems in the world. Over thousands of years, peat soils have stored enormous amounts of carbon within water-saturated soil layers. Under natural conditions, these ecosystems serve as highly effective carbon sinks and reservoirs. However, when peatlands become degraded, dry out and eventually burn, these carbon stocks can be released into the atmosphere in large quantities in the form of carbon dioxide (CO₂) and methane (CH₄) all of which contribute to global climate change.

Forest and land fires in Indonesia frequently occur on peatlands. In 2026, for example, the Ministry of Forestry reported that approximately 50 percent of fire-affected areas were located within peatland ecosystems. This figure is significant because peat fires generally produce far greater emissions than fires on mineral soils. Not only does the vegetation burn, but the carbon-rich organic soil layers themselves are consumed by fire.

For example, the extent of burned areas can be mapped through remote sensing technologies. However, burned area is only one component of emissions calculations. To determine how much carbon has been lost, researchers must also understand how deeply the peat has burned, the carbon content of the affected layers, moisture levels, and the completeness of the combustion process and emissions released from the peat soil. Each of these variables can differ from one location to another, even within the same landscape. Small differences can lead to dramatically different emission estimates.

The diversity of Indonesia’s peatlands further magnifies this challenge. Peat depth, hydrological conditions (or water levels), degree of degradation, vegetation type and fire history can all influence fire behavior and the amount of carbon released. As a result, the use of generalized emission factors often falls short of adequately representing actual field conditions. Consequently, uncertainty in emissions calculations remains high.

Through direct field measurements, the research team seeks to better understand the relationship between peat burn depth and carbon loss, observe changes in the physical and chemical properties of soil after fire, and monitor greenhouse gas emissions before, during and after burning events. Such information is invaluable for refining the emission factors from peat emissions currently used in national calculations.

More broadly, field research can help answer several questions for which data remain limited: How much do vegetation and peat layers each contribute to total emissions? How do fluctuations in groundwater levels influence carbon release? How long do fire-related greenhouse gas emissions continue after the flames have been extinguished? Answers to these questions are essential for advancing scientific understanding of tropical peat fires.