It didn't before due to a whole host of reasons, for starters the entire map of the world was completely different. I could go on and detail the scientific reasons but you are just like the young earth creationists and refuse to listen to scientific fact despite insurmountable evidence, so I wont waste my time with close-minded fools.
Sure it was a different world map and the world did not fry despite high levels of CO2, probably for a whole host of reasons, none being high atmospheric sensitivity to CO2.
But please show me the "insurmountable evidence" that manmade CO2 has caused this warming, that by the way has stopped for the last 15 years.
Please enlighten me with your facts, I have been waiting to be informed of the truth for a long time now.
So far I have only seen guessing machine results that have been wrong, followed by goal post moving, "its hiding under the oceans now".
Don't just repeat appeals to authority like the discredited cook paper "97% of climate scientists say", show me the empirical evidence showing the sensitivity of our climate to CO2.
Show me the model where they have accurately modelled our climate, taking into account natural variability , its a fact you say, show this proof you know of.
I know you cant, same as nobody can prove its low sensitivity, we just don't know yet, but it isn't looking as high as the IPCC scaremongers would have us believe for sure, but you seem to know otherwise.
Scepticism is part of science until we know the answers, to mock it shows lack of understanding of how science works.
Lets see who the fool is, I am all ears.