fkasner wrote:

The data essentially prove nothing. What those who espouse global
warming have done is posit models of the atmosphere and other
meteorological variables and then massaged the models so they can
produce time dependent results. Then they compare these to the
purportedly neutral data. If they don't match they recalculate the
models with changed parameters to make new predictions. And so forth.
When they finally get what they consider a reasonable match to their
predictions and the so-called data they proclaim the proof of their
model and the underlying bias in the model called global warming.
FK

What FKasner is saying here is absolutely true. More significantly they are
deliberately concealing this from the public. For example the following is
a link to IPCC website that, purportedly, is intended to explicate the
concept of climatic (radiative) "forcing."

http://www.grida.no/climate/ipcc_tar/wg1/214.htm#611

Therein they offer the following definition of "climatic forcing:"

"The radiative forcing of the surface-troposphere system due to the
perturbation in or the introduction of an agent (say, a change in greenhouse
gas concentrations) is the change in net (down minus up) irradiance (solar
plus long-wave; in Wm-2) at the tropopause AFTER allowing for stratospheric
temperatures to readjust to radiative equilibrium, but with surface and
tropo-spheric temperatures and state held fixed at the unperturbed values".

After reading this definition you might be scratching your head wondering
how "climatic forcing" is calculated/quantified. You won't find the answer
to this question on this page. Surely, you might think, a concept so
central to the GW argument must be accessible through the IPCC website.
Again you would be wrong. However, further down the page you will find a
hint:

"Defined in the above manner, radiative forcing of climate change is a
modelling concept that constitutes a simple but important means of
estimating the relative impacts due to different natural and anthropogenic
radiative causes upon the surface-troposphere system."

After reading how it is actually calculated (below) you might think it
rather comical that they describe it, here, as, "simple." (I suspect if we
were to put the question to the whackos here in sci.environment that they
would respond that it is simple because it is defined as simple.)

How then is "climatic forcing," actually calculated. Does it involve direct
measurement of atmospheric phenomena? Does it involve conclusions based on
laboratory data? No. It involves the methods that FKasner described above.
A more detailed description of the process can be found on the realclimate
website:

http://www.realclimate.org/index.php?p=142

Take a radiation computer model (GCM) and remove each long-wave
absorber (principally the greenhouse gases, but also clouds and aerosols)
and see what difference it makes to the amount of long-wave absorbed. This
gives the minimum effect from each component. The complementary
calculation, using only each particular absorber in turn, gives the
maximum effect. The table shows the instantaneous change in long-wave
absorption when each component or combination of components is removed
using the radiation code from the GISS GCM. (The source code is available
for those who have the patience to get it to work). This isn't a perfect
calculation but it's quick and easy and is close enough to the right
answer for our purposes.

The IPCC managed to conceal this in the first three assessment reports.
Let's not let them get away with it in the fourth.

Question: I read in one of the posts that the working draft of the fourth
assessment can be requested from the IPCC website by email request. But I
was unable to find it on the IPCC website. Please post a link.

Claudius Denk