Nice try Sylvester.. CO2 warming is an impedance to surface cooling, not a heat source. So it is INDEPENDENT of solar input flux. It will raise thermal equilibrium by approximately the same amount REGARDLESS of the state of the sun.. So if the Atmos reached those levels before, the trigger condition for your imagined "thermal runaway" was met -- UNLESS of course that period of time WAS a snowball earth.
You're the only one here talking about "thermal runaway". That's your imaginary theory, not mine, and I'm not obligated to defend what your voices told you I believe.
Back on planet earth, solar output was 4% lower, but there was much more CO2, so more heat was held in, so temperatures were about the same. Then CO2 levels did drop, and there was a snowball earth, which didn't thaw until CO2 levels rose again. Hence, the paleorecord confirms both ways that CO2 is a greenhouse gas.
And what is this ridiculous denial of "reduced solar flux" at the poles? You think the winters there are sunny? I didn't hear BillyBob say that.
His exact words were "The polar regions have had a drop of over 6.2W/M^2.", post #51.
What I heard him say was that the effect of spectral shifts would be magnified at the poles because of reduced atmos thickness.
"Would?" He used past tense, which means he is claiming such shifts have already happened. That's why we're asking him to show us the data. Or if he made an error in tense, he needs to state that.