Slide 26 of this series.
The phsyics of Water Vapor in absorbing IR is dominant over CO2 to a great degree. It is more prevalent. It can absorb more of the spectrum, and it has a larger absorbtion area per moleculte. The diagram below only shows the spectrum or wavelenght advantate of WV.
NEXT: The influence of WV on the atmosphere is huge.
These links are the topics for this section.
Modelling Temp Natural Factors
Earth and the Science of Radiation
Milankovith Overlapping Cycles