This is BS- We were over 1000 ppm, and science is learning that deep ocean CO2 was somehow churned up and released NOT by warming- but by cyclical turnover in oceans and lakes- (There is a term for it but can’t think of it right now)
The ‘consensus’ would have the low info masses believe CO2 NEVER rose to high levels before the industrial age- yet we know for a fact that it has - all due entirely to nature!
If only we had saved Pangea.............. No doubt drifted apart due to CLIMAGEDDON!