###### Abstract  
Three Earth system models (ESMs) from the Coupled Model Intercomparison Project phase 6 (CMIP6) were chosen to project ecosystem changes under 1.5 and 2 \({}^{\circ}\)C global warming targets in the Shared Socioeconomic Pathway 4.5 W m\({}^{-2}\) (SSP245) scenario. Annual terrestrial gross primary productivity (GPP) was taken as the representative ecological indicator of the ecosystem. Under 1.5 \({}^{\circ}\)C global warming, GPP in four climate zones--i.e., temperate continental; temperate monsoonal; subtropical-tropical monsoonal; high-cold Tibetan Plateau--showed a marked increase, the smallest magnitude of which was around 12.3%. The increase was greater under 2 \({}^{\circ}\)C of global warming, which suggests that from the perspective of ecosystem productivity, global warming poses no ecological risk in China. Specifically, in comparison with historical GPP (1986-2005), under 1.5 \({}^{\circ}\)C global warming GPP was projected to increase by 16.1-23.8% in the temperate continental zone, 12.3-16.1% in the temperate monsoonal zone, 12.5-14.7% in the subtropical-tropical monsoonal zone, and 20.0-37.0% on the Tibetan Plateau. Under 2 \({}^{\circ}\)C global warming, the projected GPP increase was 23.0-34.3% in the temperate continental zone, 21.2-24.4% in the temperate monsoonal zone, 16.1-28.4% in the subtropical-tropical monsoonal zone, and 28.4-63.0% on the Tibetan Plateau. The GPP increase contributed by climate change was further quantified and attributed. The ESM prediction from the Max Planck Institute suggested that the climate contribution could range from \(-12.8\%\) in the temperate continental zone up to 61.1% on the Tibetan Plateau; however, the ESMs differed markedly regarding their climate contribution to GPP change. Although precipitation has a higher sensitivity coefficient, temperature generally plays a more important role in GPP change, primarily because of the larger relative change in temperature in comparison with that of precipitation. G 2021  
over the 21 st century under the Representative Concentration Pathway [6] 8.5 W m\({}^{-2}\) (RCP8.5) in comparison with regions closer to the equator. Under 1.5 \({}^{\circ}\)C of global warming, the GPP in China is expected to increase by 15.5% \(\pm\) 5.4% on a stabilized pathway and by 11.9% \(\pm\) 4.4% on a transient pathway [7]. [PERSON] et al. [3] explored the trend features of GPP/NPP in the 21 st century under the Shared Socioeconomic Pathway [8] 24.5 W m\({}^{-2}\) (SSP245) with the Beijing Climate Model. Their results predicted the overall trends of increase in both the near-term and long-term terrestrial GPP/NPP. However, in certain districts, the trend of GPP/NPP showed an initial increase followed by a decrease. [PERSON] et al. [9] investigated the variation in NPP over the 21 st century using the Earth system models (ESMs) of the Coupled Model Intercomparison Project phase 5. The results obtained under all four RCP scenarios suggested an increasing trend of NPP over China, especially in western areas. In summary, GPP/NPP in China under different scenarios is expected to show a trend of increase in the 21 st century. However, large uncertainties exist in the various ESMs [5; 9]. Under the global warming targets of 1.5 and 2 \({}^{\circ}\)C above preindustrial levels set by the Paris Agreement, many regional impacts wait to be assessed. In particular, as the Coupled Model Intercomparison Project enters into the 6 th phase (CMIP6), more and more ESMs have distributed their latest climate simulation under the Shared Socioeconomic Pathways (SSPs). How the latest ESMs will project the future ecosystem change in China and the corresponding climate attribution remains to be determined and revealed. In a recent study on performance in presenting historical terrestrial GPP in China, three out of seven ESMs evaluated were found to perform well in terms of climatological GPP, spatial pattern, and the ecosystem-climate relationship [10].