> There is evidence for high CO2 concentrations between 200 and 150 million years ago of over 3,000 ppm, And it didn't end up well, Permian-Triassic extinction

> There is evidence for high CO2 concentrations between 200 and 150 million years ago of over 3,000 ppm, And it didn't end up well, Permian-Triassic extinction event was the biggest mass extinction in history. https://marinebiology.co/2015/04/10/greatest-mass-extinction-event-driven-by-ocean-acidification/ https://marinebiology.co/2015/04/10/greatest-mass-extinction...