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Granity · 03-01-2011, 09:53 PM

Quote:

Originally Posted by Stewart Robert Hinsley

In message , Martin
lid writes
On Mon, 3 Jan 2011 11:31:20 +0000, Stewart Robert Hinsley
wrote:

In message , Martin
lid writes
On Mon, 3 Jan 2011 09:47:40 +0000, Stewart Robert Hinsley
wrote:

In message , Granity
writes

="" a=""What mechanism do you propose operates to prevent the addition
of
greenhouse gases resulting in (on average) a warming of the climate?

Physics. .

The physics of heat transfer in the atmosphere imply that the addition
of greenhouse gases results in (on average) a warming of the climate.
What other physical mechanisms do you propose operate to prevent this
happening?

Radiation?

Radiative transfer is part of the physics of heat transfer in (in and
through if you want to be picky) atmosphere.

and? The earth loses heat via radiation.

As radiative transfer is part of the physics of heat transfer in the
atmosphere it is not another physical mechanism.

As for why increased radiation does not prevent warming, the basic
principle is that half the radiative heat absorbed in the atmosphere is
re-radiated back to the surface. This means that the incident radiation
at the surface is increased. This means that more energy has to leave
the surface.

The amount of energy radiated by the surface depends on the temperature.
(For a black body it is proportional to the 4th power of the
temperature.)

So, if the additional energy is leaving the surface by radiation the
temperature of the surface has to be higher. In other words radiation is
not a process which prevents the addition of greenhouse gases from
resulting in an (on average) increase in temperature.
--
Stewart Robert Hinsley

CO2's properties as a 'greenhouse gas' come from its absorption of infrared radiation coming from the Earth's surface (which it then re-radiates, thus keeping the heat in the lower levels of the atmosphere rather than letting it escape to space). The contention is that *all* the IR radiation which *can* be absorbed by CO2 already is, so adding more CO2 to the atmosphere can't increase the heating because there's no more radiation to be absorbed.