And yet we're making enormous policy changes with them.
So one, I don't think it's worth trying to use these models for policy. Two, sea level rise has only been 1-3 mm per year since the sixties, temp about 0.08 degrees centigrade per decade. Easily adaptable.
You can also look at the IPCC reports themselves where they admit to model "limitations". Also note the confidence level their far out proclaimations are made with. It is typically "moderate" or "low". The news pieces rarely make mention of this confidence level though.
There are plenty of articles debunking his points as outdated strawman arguments, e.g. https://climatefeedback.org/evaluation/wall-street-journal-a...