Equilibrium Sensitivity of a Climate Model to an Increase in the Atmospheric CO2 Concentration Using Different Methods to Account for Cloudiness

Variations in the equilibrium sensitivity of the INM-CM4-8 climate model to a quadrupling of the CO2 concentration are considered if changes in the cloudiness parameterization are specified in this model. It is shown that regulating the account for various mechanisms of formation and dissipation of cloudiness can lead to a change in the equilibrium sensitivity of the model from 3.6 to 8.1 degrees C, which covers more than half of the range of variation in this value in the modern climate models. To do this, the mechanisms of cloudiness formation in the atmospheric boundary layer and dissipation of clouds are regulated by mixing with unsaturated surrounding air. Regulating the mechanism of convective cloud formation influences the sensitivity, but to a lesser extent.