Re: Arctic summers ice-free 'by 2013'

On Dec 12, 12:42 pm, Mike Tullett
<mike.tullett1.for.newsgro...@xxxxxxxxxxxx> wrote:
On Wed, 12 Dec 2007 04:04:50 -0800 (PST), Keith (Southend)G wrote in
<news:a79f547f-ff86-46cd-aa21-dd7f80da7095@xxxxxxxxxxxxxxxxxxxxxxxxxxx>

http://news.bbc.co.uk/1/hi/sci/tech/7139797.stm

That's very interesting but won't come as a big surprise to some in this
ng. It seems the faster rate than previous model results is down to taking
a full account of the current thinning of the ice.

--
Mike Tullett - Coleraine 55.13°N 6.69°W posted 12/12/2007 12:42:39 GMT

Yes, but why is the ice thinner faster than expected? The answer is
that the climate models are wrong!

It seems that here and elsewhere meteorologist have always been
sceptical of the models and rightly so. The models are based on the
radiative effect of greenhouse gases but that is not the way they
alter the climate. Greenhouse gases absorb radiation and so warm the
air around them. Maximum absorption of the radiation happens in the
air closest to the surface and falls off with the logarithm of the
distance from the surface (Lambert's Law.) When you increase the CO2
concentration the layer of air close to the surface absorbsed more
radiation and hence being warmer it prevents the surface from losing
heat by conduction. Fourier's Law states that heat flow depends on
the temperature difference.

In the tropics the main greenhouse gas is water vapour, and so
increasing CO2 will not have much direct effect there. However, at
high altitudes and latitudes where the surface is covered with snow or
ice the water vapour concetration is very low and carbon dioxide is
the more important greenhouse. By raising the global carbon dioxide
concentration we also raise the altitude and latitude at which the
surface can remain snow covered during the summer, the main pre-
condition for an ice age.

The original greenhouse theory was that changes in carbon dioxide were
responsible for the climate shifts that had happened in the geological
past, especially the ice ages. That was what Arrhenius investigated
in his 1896 paper http://www.globalwarmingart.com/wiki/Image:Arrhenius_pdf
As an aside he considered what would happen if CO2 doubled as a result
of industrialisation, and is now regarded as a hero of global
warming. His calculations were based on the radiative effects of CO2.
Karl Angstrom son showed that the radiation is saturated so increasing
CO2 will not change the radiative effect. So the greenhouse theory,
first proposed by John Tyndall an Irishman, is correct, just not the
way that Ahhrenius and most scientists believe.

So CO2 is melting the Arctic ice, but when it has gone water vapour
will take over as the main greenhouse gas and temperatures there, and
all other parts of the Northern Hemisphere affected directly or
indirectly by polar air will see a major change in climate.

The ideas that greenhouse gases act mainly through conduction/
convection rather than radiation is something that has only recently
occurred to me. I would be interested in hearing from others, probably
better qualified then me, on what they think of my idea.
.

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