Human Activities Dominate Global Trends in Terrestrial Phosphorus Deposition

Atmospheric deposition of phosphorus (P) has multitudes of environmental implications, but quantifying and validating its spatial and temporal patterns remain highly challenging. Here, we integrated a detailed P emission inventory with atmospheric chemistry transport modeling and a temporally augmented mass-conserving downscaling approach to estimate terrestrial P deposition at 0.1° resolution during 2000-2019. The results reveal a 16.5% increase in global terrestrial P deposition, from 174.6 g ha^-1 yr^-1 (2.31 Tg yr^-1) in 2000 to 202.6 g ha^-1 yr^-1 (2.69 Tg yr^-1) in 2019. Among the natural sources, mineral dust predominated with emissions ranging from 1.31 to 1.50 Tg P yr^-1, followed by primary biological aerosol particles (0.14-0.15 Tg P yr^-1). Among anthropogenic sources, emissions were led by fossil fuel (1.12-1.62 Tg P yr^-1) and biofuel combustion (0.39-0.52 Tg P yr^-1), which significantly exceeded contributions from agricultural activities (0.07-0.10 Tg P yr^-1). Spatially, the net global increase in P deposition was primarily driven by increased anthropogenic emissions in China (+4.09% per year) and India (+2.98% per year), which outpaced concurrent P emission reductions in the US (-0.40% per year) and Europe (-0.04% per year). Despite the implementation of a series of clean air policies in the two countries, anthropogenic P emissions continued to climb or level off, underscoring the need for systematic monitoring to mitigate potential environmental risks.