[rktman]

So, what was growing where the giant redwoods are before the giant redwoods?

[Aliska]

Possibly other giant redwoods that burned or fell over. I don't know and didn't claim to know everything about the science or any of it, am entitled to an opinion.

[jonrick46]

The levels of CO2 in the atmosphere was so beneficial to plant life that we had forests growing all the way up to the 50th latitude.