Siberian Greening Enhances Coastal Spring Chlorophyll in Western North America

Climate change is driving unprecedented changes in terrestrial and marine ecosystems, with profound effects on global atmospheric dynamics, carbon cycling, and productivity ^1,2 . In particular, Siberia has experienced an earlier onset of the growing season ^3,4,5 and increased productivity ⁴ , contributing to regional warming ^4,5,6 and altered aerosol emissions ^7,8 . At the same time, coastal spring chlorophyll in the northwestern US and Canada is undergoing significant changes due to coastal upwelling and resulting nutrient enrichment, affecting ecological dynamics and fisheries sustainability ^9–15 . However, trends in the spring chlorophyll and its future changes remain uncertain. This study shows a significant increasing trend in coastal spring chlorophyll along the west of North America, associated with enhanced northerly winds induced by Siberian spring greening under greenhouse gas warming. Increased warming in Siberia, associated with spring greening, induces positive atmospheric pressure and northerly winds along the northwest coast of North America during spring. These winds drive enhanced upwelling, leading to elevated nitrate concentrations and significant spring chlorophyll blooms. Model simulations incorporating current and future CO2 forcings consistently confirm the observed increase in chlorophyll levels along the coastal waters of northern California, Oregon, Washington, and southern British Columbia. This study underscores the central role of Siberian spring greening in shaping the Northeastern Pacific Ocean spring ecosystem. The results highlight the complex linkages between terrestrial greening, atmospheric teleconnections, nutrient cycling, and marine ecosystems. A comprehensive understanding of these linkages is critical for predicting and managing the impacts of greenhouse gas-induced warming on fish catches and broader ecosystem dynamics. This research will help refine predictions and develop strategies to mitigate the broad impacts of climate change on marine ecosystems.