Spatial quantification of the impact of the Russo–Ukrainian War on landscape fires and greenhouse gas emissions (2022-2025)

Military conflicts and wars can trigger landscape fires that cover large territories, leading to significant greenhouse gas (GHG) emissions into the atmosphere and reducing the carbon sequestration capacity of the burned forests. Assessing the scale of this negative impact using ground-based methods is impossible due to contamination by Unexploded Ordnance (UXO) and landmines, the constant shelling, damage to monitoring systems, power outages, and a shortage of personnel. To spatially quantify the impact of the ongoing Russo-Ukrainian War on landscape fires, GHG emissions, and reductions in the carbon sequestration capacity of forests, we utilized remotely sensed data from 2022 to 2025 in combination with geoscientific approaches.First, we identified the fire perimeters using satellite monitoring data and expert estimation. We then classified the burned areas into different land cover types: coniferous forests (Scots pine and spruce) and deciduous forests (common oak, beech, hornbeam, other hardwoods, and softwoods), croplands (wheat, barley, sunflower, and corn), and other landscapes (pastures, shrub vegetation, wetlands, and water vegetation). Using Canadian Fire Weather Index (FWI) for each land cover type summarizing by calendar seasons, we estimated the attribution factor spatially, which identifies the share of landscape fires that were war-related and not caused by natural factors or human activities typical of peacetime. The assumption was that under the no-war scenario, the same weather conditions (FWI) on the same type of land cover and in the same season should cause commensurate areas of fire across Ukraine.To calculate the biomass losses due to war-related fires, we considered the land cover type, the species and age structure of the forest stands, the distribution of fires according to their intensity based on the differenced normalized burn ratio, their landscape-damaging severity, and the biomass content. On this basis, we estimated the immediate GHG emissions from war-related landscape fires as well as the longer-term biomass losses due to current forest fires and their corresponding GHG emissions.Finally, we estimated the loss of carbon sequestration capacity in the burned forests and the associated uncertainty in the results achieved. Our study has demonstrated that during the first 3 years (2022–2024) of the Russo–Ukrainian War, the GHG emissions from war-related landscape fires, including forest, cropland, grassland, and wetland fires, have been substantial, and their spatial pattern has been significantly impacted by the location and intensity of the hostilities. The corresponding GHG emissions in the immediate term were estimated to be 14.18 Mt carbon dioxide equivalent (CO2e), and in the future (long-term), the biomass losses due to current forest fires and their corresponding GHG emissions were calculated to be 32.37 Mt CO2e.