Wasn't it Socrates that said:

I've looked at clouds from both sides now
From up and down, and still somehow
It's cloud illusions I recall
I really don't know clouds at all

I love Joni Mitchell.

Wasn't it Socrates that said: — Bitter Crank

Definitely. And Euripides was definitely a better philosopher than Plato )

The quantity of CO2 that would be required to account for the young climate would have left a mineral behind that is absent from the young rocks. — frank

Those are empirical estimates that have huge margins of uncertainties associated with them. The atmospheric CO2 concentrations several million years ago are estimated roughly by a few different proxy methods that give somewhat discrepant results give or take one or two orders of magnitude. Those remaining uncertainties and open scientific questions regarding the state of the climate in the very distant past can't be used to cast doubt on our understanding of the physics of the current climate system (for the last million years or so) where the data is known much more precisely.

Those are empirical estimates that have huge margin of uncertainties associated with them. The atmospheric CO2 concentrations several million years ago are estimated roughly by a few different proxy methods that give somewhat discrepant results give or take one or two orders of magnitude. Those remaining uncertainties and open scientific questions regarding the state of the climate in the very distant past can't be used to cast doubt for our understanding of the physics of the current climate system (and the last million years or so) where the data is known much more precisely. — Pierre-Normand

I think you must be giving this thread only a small portion of your attention. No problem. :wink: