资源环境科技发展态势分析平台

The newest generation of the Coupled Model Intercomparison Project (CMIP6) exhibits a larger spread in temperature projections at the end of the 21st century than the previous generation. Here, a modular Earth System Model emulator is used to evaluate the realism of the warming signal in CMIP6 models on both global and regional scales by comparing their global trends and regional response parameters to observations. Subsequently, the emulator is employed to derive large “crossbred” multi‐model initial‐condition ensembles of regionally‐optimized land temperature projections by combining observationally‐constrained global mean temperature trend trajectories with observationally‐constrained local parameters. The warmest temperature projections are generally reduced in the optimized ensembles, whereas for the coolest projections both higher and lower optimized projections are found depending on the region. The median is only weakly affected in large parts of the globe. These regional differences highlight the importance of a geographically‐explicit evaluation of Earth System Model projections.