How vegetation greening mitigates climate-driven aridification in mid-latitude Asia

Mid-latitude Asia, one of the world’s most extensive arid zones, exhibits heightened vulnerability to climate change, manifesting in pronounced surface warming and spatially heterogeneous drought patterns. While the central-western sector has experienced intensified aridification, the southeastern regions have maintained relatively stable conditions―a disparity whose mechanisms remain insufficiently understood. This study utilizes observational analysis and numerical modeling to investigate the spatiotemporal characteristics and drivers of drought variability across mid-latitude Asia from 1982 to 2018, focusing on investigating the impacts of climate change and vegetation dynamics. Our findings reveal that the intensified Standardized Precipitation-Evapotranspiration Index (SPEI) trend in central—western mid-latitude Asia (Xinjiang: −0.016 per year, p < 0.05; Mongolia: −0.017 per year, p < 0.05) can be attributed to rising surface temperatures and declining precipitation, mediated by a persistent high-pressure anomaly over the northwestern Mongolian Plateau. This high-pressure system reduces cloud cover, increases net radiation, enhances evaporation, and suppresses water vapor transport. These conditions contribute to elevated temperatures and decreased precipitation, exacerbating drought severity. In contrast, the southeastern region benefits from weaker climatic anomalies under global warming and more pronounced vegetation greening trend (North China: 0.15 per year, p < 0.05; Northeast China: 0.08 per year, p < 0.05), which mitigates drought through hydrological processes and land‒atmosphere interactions. The enhanced evapotranspiration related to greening lowers the surface temperature, thereby creating an atmospheric cold source that feedbacks into land and water cycles. These findings reveal a biogeophysical dichotomy in drought responses across mid-latitude Asia, advancing mechanistic understanding of dryland ecosystem resilience in the context of global warming.