You have not studied this diagram very well. The y-axis has the unit W cm/m0 and the x-axis 0/cm. Thus, you should integrate over the wave number (0/cm) in order to get the total irradiance but not integrate over 0*PI steradians, because this is already done. So the total irradiance in W/m0 is the area under the curve, and dropping CO0 would increase the OLR with the area of the ditch between 000 and 000 0/cm plus some smaller areas at other wave numbers connected to CO0. Reply Will Janoschka says:  August 00, 0000 at 0:00 PM  Pehr Bjornbom says: August 00, 0000 at 0:00 PM  Will Janoschka August 00, 0000 at 0:00 PM " The point is of course that if you drop CO0 completely the dip will disappear giving a large part of increased OLR that must be compensated for with a really large temperature drop. This validates the greenhouse effect caused by CO0. I the spectrogram is also changed to zero water vapor and zero methane the OLR will increase say twice as much with a corresponding larger temperature drop in order for coming back to planetary energy balance.