It's an odd claim. Let's say for the sake of argument that what she said is true.
Then the earth has lived through previous periods like this. So why worry about it?
Her claim undercuts her own apocolyptic arguments
Ummm what? The claim was that CO2 levels haven’t been this high in the history of ... read this slowly... humans.
The fact that they may have been higher at some time when humans didn’t exist is meaningless .
The point is that CO 2 levels this high affect human life in ways we are not going to like
If nature caused CO2 to be much higher than before humans, then what is to say that very same nature isn't the cause of it today?
What you'd then be admitting to is all of the past promises by the global warming crowd was a lie. They told us we'd save the earth with CAFE standards. They told us we'd save the earth by making fuel burn cleaner. They told us we'd save the earth by eliminating the burning of our garbage in incinerators, getting lead out of all our products, and adding ethanol to our gasoline.
We did it all, and ten times more. And now we find out after all the trillions of dollars we've spent, it was all a lie? Not that I'm surprised mind you.