[aruanan]

I wonder why they didn't go back and use those approximately 90,000 data points of actual atmospheric CO₂ measurements from the 19th century.

[Ernest_at_the_Beach]

Probably would not give the results they wanted....

[Hoodat]

I wonder why they include 600,000 years of ice core data on CO2 but omit the current atmospheric CO2 level at the site where those ice cores were extracted.