text: Like water vapour, carbon dioxide also absorbs some incident Solar radiation, particularly in the 2.7 micron band. So it prevents this radiation from reaching and warming the surface. However, the atmosphere has only about 0.04% carbon dioxide, compared with about 1% to 4% water vapour. Each water vapour molecule absorbs and radiates in a far wider range of wavelengths than each carbon dioxide molecule and so, as some have estimated, the overall effect of all the carbon dioxide could be as little as 0.1% that of all the water vapour. And that effect is likely to be a net cooling effect anyway.