Soil salinization trend from 2003 to 2022 across the globe response to climate change

Abstract

Climate change affects soil salinization and is responsible for food production threats and unsustainable development. However, global salinization trend and its temporal response to climate remains unclear. Here we show global soil salinization changes from 2003 to 2022 at 500 m resolution estimated by a machine learning approach, remote sensing, climate, and geographical data. Globally, soil showed a stable trend with an average trend slope value of -0.00002 ± 0.000024 dS m-1. The trend shows a large variability across the globe depending on local water regimes, and soil salinization has intensified in semi-arid and humid areas. Soil salinization trends are influenced by soil hydro-thermal conditions. Reduced terrestrial water reserves intensify salinization, and soil moisture patterns drive salinization through a three-year lag time and a three-year accumulation effect. A soil salinity change equation was proposed describing vegetation, soil moisture, climate, and topography which can be used for guiding salinization trend evaluation. Our findings reveal the global soil salinization trend and its response to climate change, providing detailed guidance for improving soil quality under different climate and hydrological conditions.