Wildfires in the Arctic tundra of Alaska have reached levels not seen at any point in the last 3,000 years, according to a new scientific study that warns of accelerating climate-driven changes in one of the world’s coldest ecosystems.
The study, conducted by an international team of researchers from Germany, Poland, the United Kingdom, Romania and the University of Alaska Fairbanks, found that tundra fire activity during the past century has surpassed anything recorded since around 1000 B.C. The findings highlight how warming temperatures are reshaping the Arctic landscape in alarming ways.
Researchers used a multidisciplinary approach to reconstruct the region’s fire history by extracting peat soil cores from nine sites north of Alaska’s Brooks Range, along the Dalton Highway between Toolik Lake and Franklin Bluffs. These peat layers contained charcoal fragments, pollen, plant remains and microbial material, each providing clues about past fires, vegetation patterns and soil moisture conditions.
By analysing these materials and applying radiocarbon and lead dating techniques, scientists were able to trace wildfire activity over thousands of years. The results showed that fire activity remained very low for nearly 2,000 years. A modest increase occurred between about A.D. 1000 and 1200, a period marked by drying tundra soils, before fire activity declined again for the next seven centuries.
A dramatic shift began around 1900, when wildfire activity started rising sharply. By the mid-20th century, fires reached unprecedented levels as peat soils became extremely dry and woody shrubs spread across the tundra. This trend continued through 2015, the year the soil samples were collected, indicating a long-term and ongoing intensification of fire conditions.
To compare ancient fire patterns with recent events, researchers combined charcoal evidence from the peat cores with modern satellite data. Satellite records confirmed a significant rise in tundra fires since the latter half of the 20th century, with particularly frequent fires occurring in the late 1960s, the 1990s and the 2000s through the 2010s.
The study also suggests that recent tundra fires may be burning hotter and more intensely than earlier ones. Scientists noted that modern fires appear to consume more fuel and leave behind less charcoal, indicating higher burn severity and greater ecosystem damage.
The Arctic tundra is typically defined by extremely cold temperatures, low rainfall, permanently frozen ground and short growing seasons. Historically, these conditions limited wildfire activity. However, rising temperatures, drying soils and expanding woody vegetation are now creating conditions that allow fires to ignite and spread more easily.
The researchers warned that increasing tundra fires could further accelerate climate change by releasing large amounts of stored carbon from peat soils into the atmosphere. The study was published in the scientific journal Biogeosciences.