On Jul 23, 12:44*pm, Dawlish wrote:
On Jul 23, 11:23*am, "Gaz" wrote:

I'm so glad that no-one is listening to some of this morning's stuff.
Some of them abusive, from the usual quarters. Some of it quite
ridiculous. Some people thinking no-one has put any thought into this
subject except themselves.

Nobody is saying that those who (out of knowledge) promote AGW theory)
are daft. Quite the contrary!

Of course these objections have been addressed. The problem is that
more theory has been used in support of an initial theory.

The most important of these centres on the true fact that at low
pressures such as those found in the upper atmosphere, the absorption
lines broaden allowing frequencies previously transmitted to be
blocked.

The first question I would ask here is when we talk of global warming,
are we talking of a phenomenon that affects us here on the surface of
the earth or something that is happening 30,40 or 50 thousand feet
above our heads? If a temperature change measured in terms of tenths
of a degree way up there has such a significant effect down here then
by what mechanism?

The second question is more basic. All solar energy reaching the earth
must eventually leave it by means of radiation (since space is a near
perfect vacuum) However, only the very smallest proportion of heat
leaving the surface of the earth leaves either in the form of IR or if
it does reaches outer space directly. The earth surface cools
essentially through convection and latent heat used in the evaporation
of water. That radiation that is emitted is mmostly absorbed most
significantly by water vapour rather than CO2. These are the reasons
why at all times the surface of the earth is significantly warmer than
at altitude.

Radiation is signicant not here on the earth surface but at altitude
where water vapour is relatively absent and, although the proportions
of atmospheric constituent gases remain exactly the same the partial
pressures (concentrations) of all of them are much much lower and so
the relative spectroscopic properties of these gases are less
relevant. Radiation can occur from there relatively unimpeded.

So now I advanced the argument a stage further. I've no doubt that if
I delved further into the literature I would find suggested answers to
those questions also but that is hardly the point.

The AGW argument has acquired a momentum of its own and there are far
too many people involved (TV presenters, website compilers,
politicians, journalists, band wagon climbers, free loaders), some
influential, some less so, who lack the academic background necessary
even to appreciate the complexities of the issue let alone anything
else.

You apparently rank amongst their number.