Ah. Well, given that water vapor is the single largest greenhouse gas, and because it is so difficult to model because, well, clouds, they simplify it all the models to make models that that take days or weeks to run instead of years or decades.
Water vapor is an “inconvenient truth” to climate models. They take it into account, but in ways that let them say they take it into account.
It is all a sham anyway.
One of the inconvenient truths.
The other being solar forcing models that leave out all the solar factors (like solar flare particles, ion flux, solar wind) except light.
When there are periods of sunspots, the model shows less solar energy being dumped on Earth when the net amount is actually higher!
The current CMIP model includes most of the additional forcing, but isn't widely used. Most scientists are still using the old known flawed CMIP3 forcing. The software is already written, the data sets are well known, and the results fit The Agenda.
It's sorta like grandpa and grandma, who know their speedometer reads high, tooling along in the fast lane with their left tun signal blinking, at 55 (their speedometer says 65!) griping about all the young whippersnappers passing them on the right!
This counter-claim to CO2 being the cause of the warming this year is holding up pretty well.