I think you will find that periods with significantly higher or lower CO2 levels have featured vastly different flora and fauna.
I imagine you’re right. I know that when they grow my tomatoes they bump the CO2 levels up to around 1000 to get a good crop.
The changes from one to the other are usually associated with mass extinction of species.
That would be big news. Do we have some examples?
Neither we nor our foodstuffs would have flourished in some previous epochs.
Can you explain what would have prevented us flourishing ? The cold or the heat? The CO2 ?
I still think we should present the facts and not try to display data to tie in with a specific line of thinking.