Ah yes, the second point. I knew we'd be getting into saturation sooner or later.
The term "saturated" has come up, and becomes important now to understanding how extinction is tangentially related to temperature. The amount of
"saturation" refers to how long a molecule will remain relaxed, not excited by a particular wavelength (or the other way around, I guess). So a fully saturated gas would be continually excited by incoming radiation; and a half saturated gas would spend half of it's time relaxed, before absorbing more incoming radiation. Saturation varies differently at different altitudes; but all we need to know is that the IR is 100% absorbed (mostly) before it gets lost to space.
This means that saturation is not totally complete, otherwise the unabsorbable IR would escape to space.
[I typed this hastily, earlier; but I think it's expressed correctly and also applies]
The point being that as CO2 is relaxing, it absorbs more IR to become excited again. It's an equilibrium, depending on the amount of incoming radiation.
[whoops, have to catch Jay Leno's "headlines:" hehe: the Pickle/Ryder wedding; and the Gentle/Bang wedding...
Well, anyway, a certain portion of the CO2 is always losing it's energy via collisions, to the rest of the atmosphere... in proportion to it's concentration (and temperature).
This logarithmic thing really is just a misunderstood juxtaposition of two measurable parameters (or scientific concepts).
But as I said, the how, when, and where of "climate effects" are plenty open to debate.
That cirrus clouds Topic was very interesting. I'm hoping to head over that way eventually.
~Thanks again,
~SA
