Climate system properties influence asymmetry in global surface air temperature evolution under changes in carbon dioxide （CO₂） concentration； however， it remains unclear which properties contribute more significantly. Owing to the insufficient number of samples from the Coupled Model Intercomparison Project Phase 6 （CMIP6） experiments， this study utilized the output of 45 CMIP6 models and constructed 391 sets of experiments using a two-layer energy balance model that was both rapid and reproducible. The experimental results demonstrate that the Equilibrium Climate Sensitivity （ECS）， ocean heat capacity， and coefficient of vertical heat exchange in the ocean play primary roles in the asymmetry of the Global Surface Air Temperature （GSAT） evolution under a fixed CO₂ concentration rise and fall. This was achieved by altering the cooling rate after the GSAT peak during the CO₂ concentration decline period. Therefore， a deeper understanding of the ECS， ocean heat capacity， and the coefficient of vertical heat exchange in the ocean may facilitate a more scientifically realistic achievement of the goals of the Paris Agreement.