Michael Tobis wrote:
> On 10/14/06, bill <[EMAIL PROTECTED]> wrote:
>
> > From one of your responses "It seems to me your argument (which
> > peculiarly seems perfectly happy with a 7 C increase in mean
> > temperature, albeit on an unspecified time scale) remains based on the
> > idea that the greenhouse effect saturates."
> > Looked rather like a denial to me.
>
> A reasonable person would understand and acknowledge that in this
> discussion my intent is not to argue that bands don't saturate. It is
> to argue that the surface keeps warming even so.
This is the usual confusion. The saturaters somehow never come to the
point that emission also increases. The base idea is that if
atmospheric absorption increases, then the temperature of any packet of
air must increase until emission can match absorption. Absorption is
measured over a path length, so if it is saturated over 100 meters
(reduced by exp(-2) for example), it is not saturated over 10 m. If
you double the CO2 mixing ratio, the absorption will be saturated over
50 m, but not 5.
When a CO2 molecule absorbs an IR photon, the energy is transferred to
other molecules, primarily O2 and N2 as translational and rotational
energy. Thermal energy excites the bending vibration in other CO2
molecules which radiate. The relevant distances are several times the
mean free path for energy transfer between molecules and the average
path length of the IR photon. You would be gasping for breath before
they are comparable.
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