<p>Vegetation greening is often expected to increase evapotranspiration and reduce streamflow, implying a trade-off between ecosystem restoration and water supply. Here, using global hydrological observations from over 4,000 catchments and coupled land–atmosphere simulations, we find that nearly half of greening catchments exhibit simultaneous increases in evapotranspiration and streamflow, particularly in semi-arid regions. Based on the case of the Chinese Loess Plateau where the largest revegetation activity ever occurred on Earth, we show that conventional offline approaches neglect vegetation–atmosphere feedbacks, underestimating greening-induced evapotranspiration by more than 50% and misrepresenting water-availability trends. Greening reduces surface albedo and alters energy partitioning, intensifying net radiation, convection and the atmospheric efficiency of converting moisture into precipitation. This enhanced precipitation supply offsets evaporative losses and sustains or increases streamflow. Consistent results across four other global greening hotspots confirm that albedo-driven energy-mediated feedbacks are a dominant mechanism linking greening to water availability. These findings underscore the need to integrate these feedbacks into restoration and management frameworks for sustainable water and ecosystem outcomes.</p>