Increase in the greenhouse gas (GHG) concentrations and decreasing of the ozone layer concentration are the most important events that affect the atmospheric radiative fluxes and heating (cooling) rates. The goal of this study is to simulate the radiative impacts of changes in O3, CO2 and H2O concentrations on the radiative heating rates at different levels of the atmosphere. To this aim, the rapid radiative transfer model for General Circulation Models, RRTMG, has been implemented in short wavelength (SW) and long wavelength (LW) ranges for decrease in O3 concentrations and increase in CO2, O3 and H2O concentrations, respectively. Results show that decreasing of the O3 concentrations in the SW range increases downward fluxes and weakens atmospheric heating at the lower stratospheric levels. On the other hand, the atmospheric heating due to increase in GHGs (CO2, O3 and H2O) is observed at the lower troposphere. In addition, increase in CO2 and O3 concentrations leads to more cooling at the upper troposphere. Overall, the strengthening of atmospheric cooling due to the both events is evident at the upper troposphere and lower stratosphere.