Currently, mass-producible passive daytime radiative cooling materials (including metamaterial films and coatings) with solar reflectivity exceeding 95% have been applied in various fields such as building thermal management and mitigation of the urban heat island effect. Previous studies have indicated that this type of technology can indirectly mitigate global warming by reducing anthropogenic greenhouse gas emissions associated with cooling energy consumption. However, quantitative research is lacking regarding the potential of large-scale radiative cooling technology to directly mitigate global warming by reducing Earth′s energy imbalance. To fill this research gap, this study aims to quantify the immediate impact of land-based large-scale radiative cooling technology on planetary albedo. Analysis shows that in most regions, the contribution of increased surface albedo to planetary albedo is significantly weakened due to the atmosphere′s shielding effect (reflection and absorption) of solar radiation reflected from the surface. Further quantitative analysis reveals that even large-cale deployment (e.g., covering 5% of the global land area) of daytime radiative cooling technology cannot directly and completely offset the currently observed trend of Earth′s energy imbalance.