There are too many variables in the formation and depletion of water vapor to reliably model.
Don’t talk to me about computing power.
We don’t know enough about the variables to model predictions.
In my personal library I have a book by Peter Freuchen that lists several different theories regarding climactic changes. The discussion revolves around why we have climate changes and ice ages. The theories that Freuchen lists are changes in ocean currents, surface salinity, the inclination of the Earth’s axis via precession, changes in the orbit, CO2 levels, cosmic rays, galactic dust which cuts sunlight, solar output, and volcanoes.
The copyright is 1957!
IMHO, the answer is ALL OF THE ABOVE. The Earth’s climate is an incredibly complex interaction of many variables most of which we barely understand. AGW was a hoax from the beginning. It served many political and econut goals.
The jig is up.