The point I’m making with all this is: If “the total growth response of a tree is the product of all environmental factors”, and forest modelers have to separate temperature and precipitation diameter increments, plus create different models for different forest regions, how can then one accurately divine temperature over millenia from width analysis of tree ring growth from trees in a single region?

Or for that matter, how could anyone disentangle all the elements (temperature, precipitation, solar, shade, nutrients, etc.) and tell us it’s a proxy for the jet-stream position? The answer is: they can’t.