Paul Saladino· MD
1.64 million years ago the the pliocene and the pleistocene our ancestors were around this is their hominins homo sapiens homo erectus were around when carbon dioxide was i can't extrapolate exactly on this graphic patrick but i've got to imagine that i mean it looks like you know carbon dioxide might have been might have been as high as 500 or 600 or 800 or maybe even a thousand parts per million when when homo species walked the earth