
An attempt has been made to figure out the magnitude of the Green House Effect. Three different approaches have been tried. First, a purely theoretical approach is presented. Secondly, an estimation based on the observations is given. Finally, an estimate using the Radiative forcing of various Green House Gases has been given. Since the concentration of water vapor is a highly variable quantity and due to the non-availability of concentration data for some gases, the contribution of Carbon dioxide, Methane, Nitrous oxide, Chloro Flouro Carbon – 11 and 12 have been calculated and it amounts to about 75% of the total value. A special attention has been given to study the contribution of Carbon dioxide alone since it is the major man made GHG.