The scientists who interest me in this field are those who can draw on the experience of a lot of people who have come before them. And uniformly in these areas I find scepticism. People who write mathematical models of complex systems for a living tend to find the climate models very unconvincing. Geologists find the arguments very unconvincing. Engineers find the arguments unconvincing. And astrophysicists find the arguments unconvincing….
The climate models seem to be largely driven by over-fitting to a small sample set and positive feedback. The small sample set – at most 30 years of accurate data – might be enough to try and predict one or two years, but 50 year predictions? Ignoring the biggest effect on global warming – water vapour – is surely going to cause problems.
Positive feedback in engineering invariably results in unstable systems – so we have to ask why do most if not all of the climate models rely on it to get doomsday predictions? For the Earth to have survived as long as it has with a stable climate, through major events like ice-ages or volcanic eruptions, there is little doubt that a degree of negative climate feedback is essential.