A Curious Paleo Puzzle
16 hours ago Willis Eschenbach 95 Comments
Guest Post by Willis Eschenbach
I was wandering through the fabled land of X yesterday and came across the following post:
Figure 1. Post on X showing a shortened version of the original Figure 6 from the paper linked below.
Hmmm, sez I … looks like an interesting study. Paleo CO2 levels back to about 65 million years ago, which peaked at about 2000 ppmv.
I was reminded of an earlier graphic I’d done, showing paleo CO2 levels over a much longer time span. Figure 1 above only covers the Tertiary and Quaternary ages, the far right two boxes on Figure 2 below.
Figure2. Full history of CO2 since the Cambrian Explosion of life.
So I went to the source listed in Figure 1, a study yclept “Atmospheric CO2 over the Past 66 Million Years from Marine Archives” by Rae et al. The graphic below is a shortened version of Figure 6 of the Rae et al. study.
FIgure 3. Panels a) and c) of Rae et al., Figure 6
The authors have fully bought into the “CO2 Roolz Climate” theory, saying inter alia:
Changing levels of atmospheric CO2 have long been implicated in the well-documented cooling of the climate through the Cenozoic; however, outside of a handful of well-studied climate transitions, it has been hard to make a close link between CO2 and climate. Our new combined marine-based CO2 compilation shows, more clearly than in previous studies, a close correlation between CO2 and records of global temperature (based on either geochemical reconstructions and/or the state of the cryosphere) through the entire Cenozoic (Figure 6).
https://wattsupwiththat.com/2024/02/23/a-curious-paleo-puzzle/
