Are Water Vapor Feedbacks From Added CO2 Well Understood?
The issue of the relative roles of the human addition of CO2 and the resulting water vapor feedback remains an incompletely understood issue [and thanks to Tom Fuller for encouraging me to address this question]. As reported on Watts Up With That in a post titled NASA says AIRS satellite data shows positive water vapor feedback “AIRS temperature and water vapor observations have corroborated climate model predictions that the warming of our climate produced as carbon dioxide levels rise will be greatly exacerbated — in fact, more than doubled — by water vapor,” said Andrew Dessler, a climate scientist at Texas A&M University, College Station, Texas. Dessler explained that most of the warming caused by carbon dioxide does not come directly from carbon dioxide, but from effects known as feedbacks. Water vapor is a particularly important feedback. As the climate warms, the atmosphere becomes more humid. Since water is a greenhouse gas, it serves as a powerful positive feedback to the clim
