Soil moisture–atmosphere feedbacks mitigate declining water availability in drylands

Global warming alters surface water availability (precipitation minus evapotranspiration, P–E) and hence freshwater resources. However, the influence of land–atmosphere feedbacks on future P–E changes underlying mechanisms remain unclear. Here we demonstrate that soil moisture (SM) strongly impacts changes, especially in drylands, by regulating evapotranspiration atmospheric inflow. Using modelling empirical approaches, find a consistent negative SM feedback P–E, which may offset ~60% decline dryland otherwise expected absence feedbacks. The is not caused thermodynamic responses to declining SM; rather, reduced SM, addition limiting regulates circulation vertical ascent enhance transport into drylands. This effect large source uncertainty projected underscoring need better constrain improve representation SM–atmosphere processes models. Surface will change under climate impacted between land atmosphere. Soil exerts offsetting some decline.