Global Nitrogen budget 1980-2022

Human activities have profoundly altered the global nitrogen (N) cycle, with far-reaching consequences for the environment and human well-being. By integrating data from multiple sources and employing advanced modeling techniques, here we present an up-to-date comprehensive assessment of the global nitrogen budget from 1980 to 2022, quantifying the major flows and redistributions of reactive nitrogen (N_r) among the atmosphere, terrestrial ecosystems, and aquatic systems. Our analysis reveals a 49% increase in anthropogenic Nr release over the past four decades, largely driven by agricultural intensification and industrial expansion. Emissions to the atmosphere (NH₃, NOₓ, N₂O) rose by 37%, while nitrogen losses to water bodies surged by 72%, intensifying air pollution, eutrophication and climate change. Regarding the terrestrial fate of Nr, we estimate that terrestrial ecosystems eliminate approximately 100 Tg N yr⁻¹ via denitrification to N₂, while net accumulation in soils, biomass and industrial products accounts for 130-150 Tg N yr⁻¹. Hotspots of nitrogen accumulation and deficiency emerging in different regions, exacerbating regional and global inequalities. These findings underscore the urgency of coordinated global policies and region-specific strategies to mitigate nitrogen pollution and advance sustainable nitrogen management.