Unprecedented fire activity above the Arctic Circle linked to rising temperatures

Abstract

Arctic fires can release large amounts of carbon from permafrost peatlands. Satellite observations reveal that fires burned ~4.7 million hectares in 2019 and 2020, accounting for 44% of the total burned area in the Siberian Arctic for the entire 1982–2020 period. The summer of 2020 was the warmest in four decades, with fires burning an unprecedentedly large area of carbon-rich soils. We show that factors of fire associated with temperature have increased in recent decades and identified a near-exponential relationship between these factors and annual burned area. Large fires in the Arctic are likely to recur with climatic warming before mid-century, because the temperature trend is reaching a threshold in which small increases in temperature are associated with exponential increases in the area burned.