Peatland fires in Alaska will double by the end of the century

TL;DR

Alaskan peatland fires are expected to double by the end of the century due to climate change, leading to increased carbon emissions.

Contribution

A new high-resolution peatland map and machine learning models improve predictions of peat-fire dynamics in Alaska.

Findings

Reduced soil moisture, higher temperatures, and evapotranspiration are key predictors of peat-fire activity.

Peatland fires are projected to double by the end of the century under various climate scenarios.

Wildfires will increasingly affect organic-rich peat soils, amplifying carbon release.

Abstract

During recent summers, warm and dry conditions have increased the occurrence of wildfires and potentially peat-fires across Alaska. Limitations in resolving the fine-scale distribution of peatlands and climate observations have constrained our ability to accurately predict peat-fire dynamics. Using a new high-resolution peatland map of Alaska, we evaluated the climate and environmental controls of past and future peat-fire activity. Ensemble machine learning models identified reduced soil moisture, higher temperatures, and evapotranspiration as key predictors of annual total burned peatland area (tenfold CV R2 = 0.62, RMSE = 221.1 km2). By the end of the twenty-first century, models forced with climate datasets from representative concentration pathways (RCPs) 4.5, 6.0, and 8.5 emission scenarios project a statewide doubling of burned peatlands (increasing 61–121%), with regional increases ranging from 25–165% in polar, 61–95% in boreal, and 102–106% in maritime ecoregions. These projections indicate that wildfires will progressively encroach further into organic-rich moist and wet peaty soils, potentially amplifying soil carbon release across Alaska.

The online version contains supplementary material available at 10.1038/s41598-025-19682-4.

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