Saturation of the Infrared Absorption by Carbon Dioxide in the Atmosphere

Abstract

Based on new radiative transfer numerical evaluations, we reconsider an argument presented by Schack in 1972 that says that saturation of the absorption of infrared radiation by carbon dioxide in the atmosphere sets in as soon as the relative concentration of carbon dioxide exceeds a lower limit of approximately 300 ppm. We provide a concise brief and explicit representation of the greenhouse effect of the earth's atmosphere. We find an equilibrium climate sensitivity (temperature increase ∆T due to doubling of atmospheric CO 2 concentration) of ∆T ≃ 0.5 0 C.

CO2 sensitivity studies under laboratory and outdoor conditions as contribution to climate change discussions

“…18 already at 200m complete saturation at current CO2 concentrations, without significant contributions to further ATE. Schildknecht 15 using similar arguments finds that doubling of the CO2 content in air from 380 ppm to 760 ppm in one century an increase of ∆T ≃ 0.5 °C, which corresponds well with the expected values of this and other works.…”