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Increasing atmospheric CO2 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 × CO2 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 × CO2. 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. Plain Language Summary: Ongoing rise in atmospheric CO2 not only alters the magnitudes of temperature and precipitation, but also shifts their spatial and seasonal variations, reshaping climate zone distributions. Vegetation amplifies global warming and modulates precipitation through its physiological response (PHY) to rising CO2, but how this process affects the local climate zone shifts is understudied, especially in China. Using nine CMIP6 Earth system models, we find that climate zone undergoes shifts across 56.1% of China at 4 × CO2, and PHY contributes 15.2% of such changes. PHY aids the northward expansions of tropical and temperate zones, and generally shifts the regions to warmer and wetter climate from pre‐industrial to 4 × CO2. Importantly, PHY diminishes (−42.8%) the arid zone coverage, indicating an important role of vegetation to alleviate water stress in those regions. Strong PHY contributions to the total climate zone area changes caused by rising CO2 emerges in Shandong, Shanxi, Ningxia, Guangdong and Guangxi at 4 × CO2. Our results clarify the climate zone shifts at 4 × CO2 and unravel the role of vegetation physiological response on shifting future climate zone distributions in China, providing new perspective on the role of vegetation in climate system. Key Points: Climate zone shifts across 56.1% of land area in China at 4 × CO2, 15.2% of which is contributed by vegetation CO2 physiological forcingCO2 physiological forcing shifts the regions to a warmer climate through lifting temperature, expanding tropical zone northwardVegetation acts to shrink arid zone as precipitation increases through CO2 physiological forcing [ABSTRACT FROM AUTHOR]

China, the world's largest CO 2 emitter, is making every effort to transition to a low-carbon economy and fulfill its part of a concerted global commitment to combating climate change. In tandem with decarbonizing energy and industries, feasible supplementary measures are urgently needed to help remove anthropogenic CO 2 from the atmosphere. A burgeoning literature has emphasized the CO 2 removal capability of land re-naturalization (such as afforestation and wetland restoration), thereby regarding cognate land-use conversions as Nature-based Solutions (NbS) and potential climate policy options. However, little empirical evidence exists concerning the effectiveness of different land re-naturalization pathways (such as converting wetlands to forests or agricultural lands to grasslands), and it also remains unclear how NbS alternatives (i.e., land-use conversions resulting in negative CO 2 emission) and non-NbS options (i.e., land-use conversions resulting in positive CO 2 emission) could affect the social cost of carbon (SCC), a conventional measurement for prescribing carbon mitigation approaches. This study aims to fill in this knowledge gap via embedding NbS into the dynamic integrated climate-economics (DICE) model to quantify their impacts on the SCC. Using the Pearl River Delta region (south China) as a case study for the temporal horizon during 2000–2020, we find that both positive and negative CO 2 fluxes have been brought by different natural/semi-natural land conversions, affecting the SCC correspondingly. A total of 7 out of 17 types of land-use conversions could be identified as feasible NbS interventions, including forest restoration, forest-to-wetland, grassland-to-forest, grassland-to-wetland, grassland-to-cropland, cropland-to-forest, and cropland-to-wetland conversions, which could reduce the SCC values (comparing 2020 base-year with 2000 base-year) by 0.0132, 0.0009, 0.0033, 0.0030, 0.0001, 0.0082, and 0.0001 (USD/tCO 2), respectively. While the SCC is mainly determined by energy and industrial structure, the overall effect of NbS is larger than the sum of land urbanization and non-NbS land-use conversions. Via embedding the real-world inter-dynamics of land-use conversions into the SCC quantification, this study presents a pioneer assessment of the impacts of NbS on the SCC in an integrated framework, sheds important insights into the effectiveness of NbS, and offers practical implications for policy-makers to devise comprehensive policies covering all feasible CO 2 abatement options. [ABSTRACT FROM AUTHOR]