Sunlight, the Bond Albedo, CO2, and Earth's Temperature

Abstract

The main determinants of Earth's absolute surface Temperature, T, are the solar constant, S, the Bond albedo, A, and the effective emissivity for thermal radiation, e. In this note we assume that the value of the effective emissivity, e = e(C), is determined by the atmospheric concentration C of CO2. We show that the solar constant is most important, the albedo is second, and the CO2 concentration is a distant third.

Figures (1)

• Figure 1: The relative changes $d \ln T=dT/T$ of Earth's average, absolute surface temperature $T$ caused by relative changes $d \ln S=d S/S$, $d \ln C=d C/C$ and $d \ln A=d A/A$ of the solar constant $S$, the CO$_2$ concentration $C$, and the Bond albedo $A$. Relative changes of CO$_2$ have a much smaller effect on temperature than changes by the same relative amount of the solar constant $S$ or the Bond albedo $A$.