On Fri, 11 Dec 2009 06:57:27 +0100, Tom P wrote:

Bill Ward wrote:
On Thu, 10 Dec 2009 18:24:56 +0100, Tom P wrote:

I M @ good guy wrote:
On Thu, 10 Dec 2009 05:14:41 -0800 (PST), Dawlish
wrote:

On Dec 10, 1:00 pm, "Stan" wrote:
"I M @ good guy" wrote in
messagenewsfq1i5taabqfsl4nrlcst0bjh907pc1tpe@4ax .com...
On Thu, 10 Dec 2009 03:57:22 -0800 (PST), Dawlish
wrote:
On Dec 10, 10:56 am, "I M @ good guy" wrote:
AGW has to be
based on more than the simplistic assumption that CO2 increases
causes temperature increases.

Obviously it is. CO2 increases will cause temperature increases
unless other (natural) factors override the increase which is being
caused by increasing CO2. The physics behind that was settled over
a century ago. Pumping more CO2 in the earth's atmosphere *will*
increase absorption of outgoing IR radiation and it will cause
warming. That is accepted by almost all climate scientists and
physicists and whether you like it, or not, it is. The greenhouse
effect is well understood and the physics behind it really are
settled. The degree of warming that will be caused caused by
increasing the atmospheric concentration of CO2 is also settled,
unless you wish to change those physical laws.

GHGs are what cool the atmosphere, and
all the scientists think the minor trace gas is what warms the
atmosphere?

Scientists I know don't seem to think this, although they do say that
some of the minor gases have a potential greater green house effect.
Can you please give me some links so I can read up? (Not that I doubt
you but I know several people can read same article and all come up
with different conclusions due to selective reading, and may not
realise they are doing it, see my reply to article on greenhouse
effect on Mars)

Also my earlier point regarding graph is that the time scale at
bottom is not even but they are evenly spaced. But I agree about your
point regarding too small to catch the peaks and troughs etc.

That brings me to the point of my original post. Given that the
physics is settled, why isn't the earth cooler than it presently
is, given that two of the major natural varients (PDO and Solar
output) are in a state that ought to mean that they are having a
negative effect on temperatures - which they clearly aren't? They
should be causing cooling and we should not be experiencing some of
the warmest conditions in 130 years - unless the natural effects
are *not* managing to override the effects of CO2; which logically
leaves CO2 as the main driver of global temperature increase.
Unless I (and also the vast majority of climate scientists) see
something else affecting global temperatures in a greater way than
the physics shows the increases in CO2 should, I'm more likely to
strengthen my views on CO2 being the cause of GW, than not.

Why isn't it cooler? Maybe if the methods
and weather stations used 50 years ago would show more cooling, but
if you are cock-sure, no sense in exploring any possible
explanations.

I agree with Dawlish here, the sun is at a solar Minimum and global
climate should be showing, even with global warming, global average
temperature heading towards a trough, although with global warming I
would expect the min of the trough to be slightly higher than last
trough.

However with 1998 as starting point there was a slight dip followed
by rising i.e. almost steady Taking out the 1998 blip, temperatures
have only slowed down in the general rising, and look like they are
starting to speed up again.

Note to Dawlish and good.guy try and keep tone friendly even if you
disagree on this. Debate can be fun even if you think other guy is
talking a load of rubbish.


I agree entirely with your remarks on keeping the tone reasonable,
Stan, even when so many scientists are tarred with a "nucase" brush
they simply don't deserve.

I don't even believe fully that CO2 is the main driver for GW; I just
think, on the basis of evidence, that it is likely to be - unlike guy,
who even denies the science and says that GHGs *cool* the atmosphere.
Well, I'll just point out again that the vast majority (and I make no
apology for using that term again, as it is true) of climate
scientists and physicists would regard that as twaddle. Not just me,
guy, but almost everyone else.

You're joking aren't you?

If not, state what you (and the scientists
and physicists) think cools the atmosphere after the sun warms it, the
outgoing energy has to equal the incoming.

[[Please note: I do not call rational scientists names, it is the
foul mouthed idiots posting in alt.global-warming nonsense about
absolute certainty in AGW]]


Ok, here we go - the temperature at which the earth is in radiative
equilibrium with the incoming solar energy is around -20°c. This is the
temperature of the atmosphere at an altitude of around 6km - I have to
say "around", because this varies by latitude, but for the sake of
simplicity if we are going to get anywhere in the discussion, we have to
stick to averages and approximations. So, at this altitude, we can say
for simplicities sake that the LWR is being emitted by the GHGs in the
atmosphere at this altitude. (There is also a component that gets
through from the surface directly in certain spectral bands, which we
leave aside). That means that in a very strange sense of the word, GHGs
"cool" the atmosphere. It's an expression that denialists (sorry,
sceptics) are fond of using even if it doesn't really mean anything.
It's like saying that if I wear an anorak, the anorak "cools" me because
my body heat ultimately can only escape from the surface of the
anorak...

Good analogy. If you were wearing a Dewar flask, you'd melt down,
because there'd be no way to lose the heat you generate.

That aside, the next thing to note is that the temperature at the
surface is always higher than the temperature at the -20°c level as a
result of the Lapse Rate.
The Lapse Rate is a consequence of the hydrostatic equation and the
gas laws. This is basic physics. The exact amount depends on the amount
of water vapour in the atmosphere, but this again is limited by the
Clausius-Clapeyron equation, which in turn is derived from the
fundamental physics of thermodynamics.

And the mass of the atmosphere.

Now, the important thing to note is that the composition of GHGs at
this altitude is not the same as the surface. At the surface, the higher
temperature allows water vapour to exist in large quantities measurable
in percentages. As we go up higher in the atmosphere, the temperature
drop (lapse rate) causes the maximum water vapour content to drop
dramatically. Again, the relationship between temperature and saturation
vapour pressure is determined by Clausius-Clapeyron. That means that at
6km altitude, instead of being the overwhelming GHG ,water vapour is
less than 10 times the concentration of CO2 - still higher than CO2, but
with the result that changes in the CO2 concentration are by no means
negligible, but have a direct effect on the overall greenhouse gas
effect. Note we are talking about the MAXIMUM concentration possible of
water vapour - at any moment, the actual concentration can be even
lower.

Nice description, Tom. You included part of the WV effect, so you're
even closer than before. All you need to do now is ask yourself where
the WV went as it convected upward. I'm sure you'll immediately realize
it condensed into clouds and released the latent heat it absorbed from
the surface. Otherwise there'd have to be the same concentration aloft
as below.

Since clouds are broadband radiators, they efficiently radiate that heat
as LWIR from the top of the cloud directly to space, because, as you
pointed out, there is very little WV remaining at high altitudes to
absorb it.

The warmer the surface, the more WV (higher specific humidity), so the
condensation temperature (dew point) is higher, causing clouds and
radiation to occur at a lower altitude. That increases the radiated
power by the S/B T^4 relation, so forms a strong negative feedback. The
warmer the surface, the stronger the cooling effect.

Any small change in 15u CO2 emission is easily swamped out by that
regulating mechanism, so CO2 can't have much of an effect on surface
temperature. That's set by the properties of water and the mass of the
atmosphere, via the lapse rate.

Congratulations on your progress. You may be ready to try Miskolczi
again:

http://www.landshape.org/dokuwiki/doku.php?id=introduction
(Dr. Noor van Andel)

http://www.met.hu/doc/idojaras/vol111001_01.pdf
(Dr. Ferenc Miskolczi)



Bill, if you could finally get round to the idea that there are climate
researchers in the world, and Miskolczi is not one of them, you could
make a lot of progress.


Hey, research away, just don't ask me to
pay extra unless you can send some warmer
weather this direction, I will pay for warmer
weather gladly.