The sensitivity of the global climate is essentially determined by the radiative damping of the global mean surface temperature
anomaly through the outgoing radiation from the top of the atmosphere (TOA). Using the TOA fluxes of terrestrial and reflected
solar radiation obtained from the Earth radiation budget experiment (ERBE), this study estimates the magnitude of the overall
feedback, which modifies the radiative damping of the annual variation of the global mean surface temperature, and compare
it with model simulations. Although the pattern of the annually varying anomaly is quite different from that of the global
warming, the analysis conducted here may be used for assessing the systematic bias of the feedback that operates on the CO
2-induced warming of the surface temperature. In the absence of feedback effect, the outgoing terrestrial radiation at the
TOA is approximately follows the Stefan-Boltzmann’s fourth power of the planetary emission temperature. However, it deviates
significantly from the blackbody radiation due to various feedbacks involving water vapor and cloud cover. In addition, the
reflected solar radiation is altered by the feedbacks involving sea ice, snow and cloud, thereby affecting the radiative damping
of surface temperature. The analysis of ERBE reveals that the radiative damping is weakened by as much as 70% due to the overall
effect of feedbacks, and is only 30% of what is expected for the blackbody with the planetary emission temperature. Similar
feedback analysis is conducted for three general circulation models of the atmosphere, which was used for the study of cloud
feedback in the preceding study. The sign and magnitude of the overall feedback in the three models are similar to those of
the observed. However, when it is subdivided into solar and terrestrial components, they are quite different from the observation
mainly due to the failure of the models to simulate individually the solar and terrestrial components of the cloud feedback.
It is therefore desirable to make the similar comparison not only for the overall feedback but also for its individual components
such as albedo- and cloud-feedbacks. Although the pattern of the annually-varying anomaly is quite different from that of
global warming, the methodology of the comparative analysis presented here may be used for the identification of the systematic
bias of the overall feedback in a model. A proposal is made for the estimation of the best guess value of climate sensitivity
using the outputs from many climate models submitted to the Intergovernmental panel on Climate Change.