The response of the regional and global climate to the changes of the external forcing can be model dependent. Here we analyze two large ensembles from two CMIP6 class models – Community Earth System Model  version 2 (CESM2) and Energy Exascale Earth System Model version 2 (E3SMv2)  to study the contributions of different forcings to the changes of the surface climate during the 20th century. We found that the simulated surface climate is much cooler during 1920-2014 in E3SMv2 than observations, but that in CESM2 evolves similarly as the observations. EOF analysis of the ensemble mean surface temperatures shows that the anthropogenic aerosols seems play an important role in determining the surface climate response. Further analysis shows that the weaker mean AMOC state in E3SMv2 may be responsible to the cooler 20th century climate in E3SMv2 than in CESM2.