This ‘modern-looking’ pattern suggests that those ancient carbon dioxide levels could not have been as high as previously thought, but were more modest, at about five times current levels (they would have had to be somewhat higher than today’s, because the sun in those far-off times shone less brightly).
"Mssrs Williams, Zlackiewicz, and Vanderbrouke, can we discuss something here?" - Johnny Suntrade
"Certainly."
"Mssrs Williams, Zlackiewicz, and Vanderbrouke, you say that there is an accepted paradox during the Ordivician, given high pCO2 yet rapid glaciation, do you not?"
"Yes."
"And Mssrs Williams, Zlackiewicz,and Vanderbrouke, you maintain that the climate, and its variation, was similar to recent era's, do you not?"
"We do."
"Then you maintain that given the Sun's reduced insolation (intensity) during the Ordovician that pCO2 of that era simply could not be as high as previously suggested (15x) because the climate was the same as today, do you not?"
"We do so say."
"Then Mssrs Williams, Zlackiewicz, and Vanderbrouke are you not explicitly declaring that pCO2 in Earth's atmosphere is the cause of Earth's climate conditions?"
"Hmmmm, I guess we are saying that, yes, of course."
"Well Mssrs Williams, Zlackiewicz, and Vanderbrouke, that appears to us circuitous and presumptous logic. For after all that is the question of today is it not? I mean given that that is a totally arbitrary assumption, how can the Proceedings for the National Academy of Sciences allow you (as peer reviewed) to make such a circuitous statement, that because the climate was the same, pCO2 coupled to the Sun's output had to be the precursor for that era's glaciation?"
"Ahem, well Son, we do have to make some assumptions, and you know this WAS reviewed by the PNAS editors."
"OK, just saying. At least you do now consider the proper chronological proportions, hundreds of millions of years, to gain some perspective on phenomena that is yet significantly beyond our modeling comprehension. But then of course, 'the science is in' according to BO." -
Johnny Suntrade