A second example is sunlight striking a black pavement. Little visible light is reflected off it, but there is lots of infrared, which we feel as heat. Once we accept that there is a wavelength shift to longer wavelengths, then the energy associated with these longer wavelengths are trapped by the greenhouse gases in the upper atmosphere. It is not because the tropopause was put there to separate the two . Once something gets into stratosphere, it stays there.
Fluorocarbons are example.
Pinatubo is another. Gas molecules scatter light. The shorter the wavelength, the more it is scattered. Blue has the shortest wavelength and is the most scattered. That s why the sky seems blue.