Irrigation drives dryland productivity gains in Asian endorheic basins

The ecologically fragile Asian Endorheic Basins (AEB) recently exhibited a pronounced productivity increase despite regional drying—a paradox known as the ‘greening despite drying’ dilemma. To quantify its drivers, we integrated satellite observations with Dynamic Global Vegetation Models (DGVMs) from 2001 to 2023. We show that 25.2% of the AEB experienced significant productivity gains, heavily driven by rapid irrigation expansion (43.2%), while climate change and CO2 fertilization played minor roles. Crucially, Terrestrial Water Storage Anomaly (TWSA) analysis reveals these gains coincide with accelerated water depletion, confirming an unsustainable water-carbon trade-off where productivity gains are achieved at the expense of regional water storage. Furthermore, state-of-the-art DGVMs significantly underestimated this irrigation-driven productivity trend, incorrectly attributing it primarily to climate change. Our findings underscore the growing dominance of anthropogenic influences in shaping dryland landscapes. This model-observation mismatch highlights an urgent need to improve DGVM representations of irrigation activities and the severe sustainability risks posed by groundwater depletion. Irrigation-driven greening in Asian endorheic basins has boosted vegetation productivity despite accelerated water depletion, revealing an unsustainable water-carbon trade-off, based on satellite observations and dynamic vegetation model comparisons from 2001 to 2023.