Greenhouse effect from the point of view of radiative transfer

TL;DR

This paper analyzes the Earth's radiative power balance and estimates the greenhouse effect of CO2, concluding it contributes about 21% to observed global warming from 1880 to 2010, excluding feedback mechanisms.

Contribution

It introduces an effective atmospheric column approximation and provides a quantitative estimate of CO2's radiative contribution to global warming.

Findings

CO2 contributes approximately 21% to global warming since 1880.

The paper derives an integral formula for outgoing long wave radiation based on greenhouse gas column density.

Limits of radiative forcing are estimated considering true absorption and coherent scattering.

Abstract

Radiative power balance of a planet in the solar system is delineated. The terrestrial powers are transformed to average global flux in an effective atmospheric column (EAC) approximation, its components are delineated. The estimated and measured secular changes of the average global flux are compared to the fluxes derived from the Stefan-Boltzmann law using the observed global annual temperatures in the decades between 1880 and 2010. The conclusion of this procedure is that the radiative contribution of the greenhouse gas ${\rm CO}_2$ is some $21\pm 7$~\% to the observed global warming from the end of the XIXth century excluding the feedback mechanisms playing determining role in the climate system. Stationary radiative flux transfer is treated in an air column as a function of the column density of the absorbent. Upper and lower limit of radiative forcing is given by assuming true absorption and coherent scatter of the monochromatic radiation. An integral formula is given for the outgoing long wave radiation (OLR) as a function of column density of the components of greenhouse gases.