While end Permian CO2 levels were 2000ppm to 3000ppm, the sun was substantially cooler back then.
With the hotter sun of today similar forcing might occur at much lower CO2 levels.
Today's C02 is at around 412ppm, plus we have added methane and nitrous oxide gases, and others, which takes us to an equivalent of about 500ppm CO2 forcing, and rising.
Could current CO2 levels kick off feedback loops that bring on a Permian 2000ppm+?
Could we be kicking off a Permian event already?
Interesting article here ... https://www.skepticalscience.com/Lee-co ... ating.html
A study ... https://www.pnas.org/content/111/9/3316.short