Unraveling the Role of Vegetation CO₂ Physiological Forcing on Climate Zone Shifts in China

Increasing atmospheric CO 2 causes substantial spatial and seasonal changes in air temperature and precipitation through its radiative (RAD) and vegetation physiological (PHY) effects. However, it remains poorly understood on how these two effects impact the integrated climate zone shifts over China. Here, we disentangle the RAD and PHY effects on the shifts of Köppen‐Geiger climate zones from pre‐industrial to 4 × CO 2 in China using nine Earth system models. We find that climate zone changes over approximately 56.1% of China, and PHY contributes 15.2% of such changes at 4 × CO 2 . PHY shifts regional climate to warmer and wetter classifications, shrinking (−42.8%) the arid zone distributions and promoting (26.8%) the tropical zone northward extensions. Our findings highlight the critical role of vegetation in reshaping the overall climate zone distributions, yet introduce potential risk to climate mitigation and adaptation.