On the direct impact of the CO₂ concentration rise to the global warming

Physik-Department E11, Technische Universitaet Muenchen - James-Franck-Str. 1, 85748 Garching, Germany

Received: 27 March 2013
Accepted: 15 October 2013

Abstract

The growing amount of carbon dioxide in the atmosphere is often considered as the dominant factor for the global warming during the past decades. The noted correlation, however, does not answer the question about causality. In addition, the reported temperature data do not display a simple relationship between the monotonic concentration increase from 1880 to 2010 and the non-monotonic temperature rise during the same period. We have performed new measurements for optically thick samples of CO₂ and investigate its role for the greenhouse effect on the basis of these spectroscopic data. Using simplified global models the warming of the surface is computed and a relatively modest effect is found, only: from the reported CO₂ concentration rise in the atmosphere from 290 to 385 ppmv in 1880 to 2010 we derive a direct temperature rise of . Including the simultaneous feedback effect of atmospheric water we still arrive at a minor CO₂ contribution of less than 33% to the reported global warming of . It is suggested that other factors that are known to influence the greenhouse effect, e.g. air pollution by black carbon should be considered in more detail to fully understand the global temperature change.