I understand what he is saying.
My point is this, what is “normal shielding”?
Is there such thing as “partial” shielding or is it like being “just a little bit pregnant”?
The atmosphere either shields or it doesn’t, if it does, we’re fine, if it don’t we’re so screwed.
It’s an overall effect of certain atmospheric gases on how much of the incoming sun energy is kept on the globe rather than either being bounced away before reaching the surface or radiating back out into space from the surface. A larger proportion of such a gas in the atmosphere produces more of the effect.
Carbon dioxide is one gas in the atmosphere that has this kind of effect. It isn’t the only gas that does.
It’s kind of a “backwards shielding.”