CO2 wasn’t higher in the Little Ice Age and certainly not 10-15 times higher. There were prior periods in earth’s history when CO2 was 10 times higher or more and I believe some of those were cold (or at least not excessively warm). Those were millions of years ago. So there is paleohistorical support, but not historical support (although there are cases of spot measurements made in the 1800’s being high from local conditions).
From the link I provided:
The atmospheric CO2 concentration was many times higher than today in almost all earlier geologic periods when no runaway greenhouse effect occurred. For example, during the Jurassic period the CO2 concentration was at least 10 times higher than today, and during the Cambrian period it was at least 10-15 times higher than today. Interestingly, during the late Ordovician period the earth experienced an extremely cold glacial period despite the fact that the CO2 concentration was at least 10 times higher than today.
Do you disagree with that? I am not exactly sure which part of that was the Little Ice Age but CO2 was extremely high during long periods before man ever entered the scene.
I first responded to this comment by you:
Greenhouse gas theory is settled and CO2 increases will cause some slight warming. Manmade CO2 releases cause most of the observed atmospheric CO2 increases.
The link provided disagrees that greenhouse gas theory is settled. In fact, the purpose of the discussion is to explore why it was quickly declared settled without the normal scientific inquiry and why those who did not want to rush to judgement are vilified. Why were many scientists who were listed as in agreement later to declare that they were never asked nor do they agree. Also many of the scientists listed as in agreement are not scientists in that field at all. That deception itself raises doubt about the conclusions of the AGW crowd.
I encourage you to go to the link. It is not a political blog. It is a scientific one.
I am also not sure of why you are distinguishing between historic and geologic records. Surely certain historic records are as questionable as interpretations of geological data.