Projected intensification of soil salinization in global drylands under future aridity increase

Soil salinization threatens agricultural production, water management, and ecosystem health. Yet, how increasing aridity will reshape 21st-century soil salinity patterns across drylands, particularly in croplands, remains unclear. Here, we compile a relatively comprehensive global soil salinity dataset from the past two decades, projecting future dryland soil salinity dynamics using climate-driven machine learning models with multiple covariates, including dynamic dryland extent and human influences. Our results show an 8% expansion of global drylands saline soils under increasing aridity by 2100 (SSP5-8.5) relative to 2004–2023. Southwestern US, Mexico, southern Europe, central South America, eastern and southern Africa are highest-risk hotspots. We further show dryland croplands face serious salinization, especially irrigated systems, where half of these newly salinized areas project more than 4.9% (maize), 17.2% (dryland rice), 3.3% (sorghum), and 21.2% (wheat) potential production losses. Our findings inform long-term adaptation strategies to mitigate emerging salinization risks and sustain water and food security.