Europe’s forests are losing aboveground biomass at an unprecedented rate, with annual biomass loss per hectare increasing by 46% since 2018 compared to the previous three decades according to a new satellite based study published in Nature Geoscience.
Researchers from the Technical University of Munich analysed satellite data from 1985 to 2023 to assess changes in forest biomass, which represents the amount of carbon stored in trees. The study found a sharp rise in biomass loss after 2018, raising concerns that Europe’s forests are becoming less effective at absorbing carbon dioxide as climate change intensifies.
Unlike earlier studies that focused mainly on tree cover, the researchers combined satellite observations of forest cover with biomass density data to estimate carbon losses more accurately. The analysis identified 2018 as a turning point, particularly across Central Europe, where forests contain large amounts of standing timber but have become increasingly vulnerable to drought, heatwaves and bark beetle infestations.
The study found that prolonged drought weakens trees by reducing their ability to produce protective resin, making them more susceptible to bark beetle attacks. Countries including Germany, the Czech Republic and Poland experienced extensive forest damage following severe droughts beginning in 2018.
Central Europe emerged as a major carbon hotspot because its forests store higher amounts of biomass. In Germany, disturbed forests now lose an average of about 125 tonnes of biomass per hectare annually, equivalent to around 230 tonnes of carbon dioxide emissions.
Researchers found that forest management activities, including timber harvesting, accounted for 82% of total biomass losses between 1985 and 2023, while natural disturbances such as drought, insect outbreaks, storms and wildfires contributed 18%. However the share of natural disturbances increased from 17% during 1985–2017 to 23% between 2018 and 2023, highlighting the growing influence of climate related impacts.
The findings also indicate that Europe’s forest carbon sink has weakened significantly. Between 2020 and 2022, forests stored around 72% less carbon dioxide than in earlier years, reducing their role in offsetting greenhouse gas emissions.
Scientists warned that this trend could undermine the European Union’s target of removing 310 million tonnes of carbon dioxide equivalents annually from the atmosphere by 2030 through forests and other land use sectors.
The researchers said forests can recover naturally over time, but increasing droughts, heatwaves and pest outbreaks may slow regeneration. They recommended planting more climate resilient tree species, improving forest diversity, conserving soil moisture and strengthening satellite based monitoring to support long term forest management and climate adaptation.