The atmosphere contains about 20,000 PPM greenhouse gases. The increase of 100 PPM CO2 over the past century, represents a 0.5%increase in total greenhouse gases. The graph below shows the frightening reality. Nothing is happening to the climate system.
CO2 absorption spectra is largely saturated by 30 PPM, and the small increase in DLWR over the last century is mainly due to increased blackbody radiation as CO2 increases.