Accelerating biomass loss from forest disturbances across Europe

Abstract

Forest disturbances are rising globally due to climate change and land-use pressures, weakening the terrestrial carbon sink. However, declines in aboveground biomass from tree cover loss remain poorly quantified, limiting our understanding of the role of disturbances in global carbon dynamics. Here we present a spatially explicit estimate of aboveground biomass losses from natural disturbances and harvest across Europe’s 216 million hectares of forests, using satellite remote sensing. From 1985 to 2023, gross aboveground biomass losses totalled 6.5 ± 0.8 Pg. Of these, 18% were caused by high-severity natural disturbances, whereas stand-replacing harvests accounted for 82%. From 2018 onward, aboveground biomass losses increased by 46% reaching annual values unprecedented in the preceding four decades. This acceleration coincided with high natural disturbance activity in biomass-rich temperate forests. After 2018, the sensitivity of aboveground biomass loss to disturbance area increased substantially, suggesting that even small increases in natural disturbances can result in large losses. As climate-driven natural disturbances intensify, we thus expect sustained aboveground biomass losses across Europe, despite policies to enhance the forest carbon sink until 2030. Satellite observations reveal accelerating aboveground biomass loss across Europe’s forests since 2018, increasingly driven by natural disturbances. These trends weaken the forest carbon sink and challenge climate mitigation efforts through forest policy.