I don't see any mentioning of ice ages in that quote. If you want to argue that no meaningful science can be done with data from 1500, then of course the answe

I don't see any mentioning of ice ages in that quote. If you want to argue that no meaningful science can be done with data from 1500, then of course the answer of the effect of human CO2 output has to wait for a couple of million years. The whole research is then impossible in your opinion. I don't know about that... As for Patterson's claims, I am no climatologist, so I can't comment. I don't think CO2 is generally thought to be the only thing affecting temperatures. Ok, off the top of my head: it is known that ice ages affect temperatures. That must probably be independent of CO2 (ice ages are not driven by CO2 changes), otherwise Patterson's remark would make no sense. So there is clearly at least one other known factor (the one that brings about ice ages), which Patterson conveniently forgets to mention. What do you say?