Abstract Aerosols play a very important role in climate change with large uncertainties. Using the multimodel results from CMIP6, we analyzed the aerosol effective radiative forcing (ERF) and aerosol-induced surface air temperature (SAT) change in China in the present day (PD; 11-yr mean of 2004–14) relative to the preindustrial (PI) time (11-yr mean of 1850–60). With the increase in the anthropogenic emissions, the simulated surface PM2.5 concentration and aerosol optical depth (AOD) averaged over eastern China (EC; 18°–44°N, 103°–122°E) increased by 21.43 ± 7.58 μg m−3 and 0.47 ± 0.33, respectively, from PI to PD. The simulated aerosol ERFs in EC were −4.91 ± 2.56 and −5.35 ± 2.40 W m−2 from equilibrium and transient simulations, respectively. The simulated change in SAT caused by the increases in aerosols was −1.37° ± 0.38°C in EC from PI to PD. The simulated values of equilibrium and transient climate sensitivity to aerosols (CSA; aerosol-induced SAT change per unit aerosol ERF) in EC were 0.236° and 0.222°C (W m−2)−1, respectively. By using the observed AOD from MODIS to constrain aerosol ERF, the constrained aerosol equilibrium and transient ERFs over EC were −4.66 and −4.93 W m−2, respectively, which were smaller in magnitude than the simulated values directly from the models. By using the observed SAT from the Climatic Research Unit temperature version 5 to constrain aerosol-induced cooling, the surface cooling caused by aerosols was magnified to −1.47°C. The adjusted CSA after the constraint was calculated by dividing adjusted aerosol-induced SAT change by adjusted aerosol ERF. Adjusted equilibrium and transient CSA values in EC were 0.32° and 0.34°C (W m−2)−1, respectively.
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