Real science with links to other informative articles. mdn, you are excused, wouldn't want you to hurt yourself. CO2 – An Insignificant Trace Gas? – Part Eight – Saturation The Science of Doom Introduction This is the long-promised eighth part of the seven-part series on CO2 basics. Part One introduced the idea of CO2 with some basic concepts. Part Three opened up the radiative transfer equations, not solvable on the pocket calculator. Part Five showed two important solutions. And Part Seven showed the current best solutions along with what radiative forcing actually means, and where the IPCC logarithmic formula comes from. The even numbers in the series shouldnt be ignored either, especially Part Four which explained band models vs line by line (LBL) calculations. Now the concept of saturation is one that everyone wants an answer to. Saturation, however, means different things to different people. Consider shining a torch through sand. Once you have a few millimeters thickness of sand, no light gets through. So adding a meter of sand wont make any difference. Thats how most people are thinking about saturation and that is the perspective that we will look at in this article: For CO2 will doubling CO2 (from pre-industrial) levels add any more warming? And will doubling it again add any more? The answer already noted in earlier parts of this series is yes, but of course, everyone wants to know why, or what this means for the idea of saturation. Boringly, we will first look at some results from the radiative transfer equations.