Dr. Sweger's new paper, Earth’s Climate Engine (PDF), finds that if carbon dioxide has any effect on climate, it must be negligible. Instead, he finds on the basis of data and theory that water vapor is the dominant influence on climate, and its influence is the opposite of that assumed by the IPCC climate computer models.
From the Executive Summary:
… While models can be useful, the results must be compared to actual measurements, i.e. data. Data is the language of science, but little has been done in that regard with the climate change models.SOURCE
It is the premise of the author that water vapor is the dominant influence in determining and understanding global climate. Water vapor is much more abundant in the atmosphere than carbon dioxide, and its physical properties make it more important as well. During daylight hours it moderates the sun’s energy, at night it acts like a blanket to slow the loss of heat, and it carries energy from the warm parts of the earth to the cold. Compared to that, if carbon dioxide has any effect it must be negligible. Thus, the purpose of this paper is to explore the effect of water vapor on climate.
Detailed calculations and analysis of data from several locations clearly demonstrate that the effect of water vapor on temperature dominates any proposed effect of carbon dioxide. Furthermore, it is clear from the data presented that water vapor acts with a negative feedback on temperature, not a positive one. That is, the data demonstrate that increasing the level of water vapor in the atmosphere results in a decrease of temperature, not an increase as predicted by the climate models. In essence, atmospheric water vapor acts as a thermostat.
These results call into question the validity of using the results of the current general climate change models, particularly as the basis for policy decision making.