Water vapour feedback is simply written into climate models as parameters?

Over in another article, a commenter claims: ..Catastrophic predictions depend on accelerated forcings due to water vapour feedback. This water vapour feedback is simply written into climate models as parameters. It is not derived from any kind simulation of first principles in the General Circulation Model runs (GCMs).. [Emphasis added] I’ve seen this article of … Continue reading Water vapour feedback is simply written into climate models as parameters?