A physical demonstration of the increase in global surface energy due to increasing PCO2

Abstract

Abstract Although study of the effect of energy-absorbing gases in our atmosphere has a two-hundred year history and an unequivocal explanation based on scientific observation and theory, a significant fraction of the public and even a few scientists doubt the correlation between the increasing the partial pressure of atmospheric carbon dioxide (PCO2) and the observed increase in terrestrial temperature over the past 120 years. Although the basic science showing that CO2 would absorb the infrared radiation emitted by the earth produce a surface-warming effect was first calculated by Arrhenius in 1896, the issue was neglected by the scientific community for decades. Today there are ample climate models of the climactic effects arising from the forcing term of increasing PCO2. In this paper we follow Arrhenius’ concept, although we use the HITRAN database as the input to prove the connection between earth’s surface temperature and atmospheric absorption of terrestrial radiation. The spectra of CO2 are enormously complicated, broadened by Fermi Resonance, and intense because of the quantum coupling of the rotation of CO2 to its bending. The absorption by CO2 reduces the transmittance of the Earth’s thermal radiation through the atmosphere, which in turn results in heating of the surface. The model does not make any predictions other than that the global temperature will increase as a function of PCO2. A rigorous statement of that connection will hopefully foster greater appreciation of the significance of atmospheric chemistry. We hope that the presentation of a simple model will give scientists the impetus to reach out to the public with lucid explanations based on physical principles.