Increasing atmospheric evaporative demand across the Tibetan plateau and implications for surface water resources

The Tibetan Plateau, known as the "Asian water tower," is a hotspot for complex hydroclimatic changes. We reveal that the previously decreasing atmospheric evaporative demand (E_o ) trend at the end of the 20^th century has reversed over the last two decades. Although both wind stilling and solar dimming have persisted, their effects on E _o rates have been overshadowed by increasing air temperatures and decreasing relative humidity, leading to a net rise in E _o for 1980-2015. Using the empirical "top-down" Budyko approach, we estimate that across seven sub-catchments draining the Tibetan Plateau, a 10% increase in annual-averaged precipitation, assuming all other factors remain constant, would lead to a 15%-19% increase in streamflow. Conversely, a 10% increase in annual-averaged E _o would decrease streamflow by 5%-9%. Our findings provide a deeper understanding of the accelerating hydroclimatic changes and their impact on surface water resources in the Tibetan Plateau.