A Radiative-Convective Model Study of the CO2 Climate Problem

Abstract

A radiative-convective model study of the increase in global surface temperature ?Tg due to an increase in the CO2 concentration is presented. The model considers several weak bands of CO2 which contribute about 30% to ?Tg. A comparison study of the various published results with the present analysis indicates that, for the CO2 bands in the 12?18 µm region, the best estimate of ?Tg for the constant cloud top radiative-convective model is about 1.9 K for a doubling of the CO2 concentration. The inclusion of the CO2 bands in the 10 and 7.6 µm regions increases the value of ?Tg to about 2 K. The computed value of ?Tg is very sensitive to radiative-convective model assumptions regarding cloud top and relative humidity. Because of this sensitivity the estimated value of ?Tg for a doubling of the CO2 concentration ranges from 1.98 to 3.2 K.