[ RadSafe ] Re:"State of Fear", false greenhouse analogy

[Dukelow, James S Jr]

Rainer Facius wrote and Jim Dukelow has interpolated some comments:
-----Original Message-----
From: Rainer.Facius at dlr.de [mailto:Rainer.Facius at dlr.de] 
Sent: Wednesday, February 22, 2006 1:57 AM
To: farbersa at optonline.net; Dukelow, James S Jr
Cc: schapel at chapelconsulting.com; idias at interchange.ubc.ca;
didi at tgi-sci.com; radsafe at radlab.nl
Subject: AW: [ RadSafe ] Re:"State of Fear", false greenhouse analogy

Jim:

"This is a false analogy"! That is what I wanted to convey and what
apparently I failed to achieve.

In an actual greenhouse it is NOT the spectral transmissivity of the
glass cover/surface which determines the internal temperature - IN
CONTRAST to the temperature of a body whose thermal equilibrium with its
surroundings is established by radiation only (barring of course
internal energy sources).

[JSD comment:  The false analogy is not Arrhenius' use of the phrase
"greenhouse gas", which although not perfect is pretty good, but rather
Rainer's suggestion that removing the side panels of a greenhouse has
ANYTHING to do with the greenhouse effect in the atmosphere.  In an
actual greenhouse the warming is due to a combination of low
transmissivity of long-wave radiation by the glass and the glass
providing a barrier to prevent the convective removal of the trapped
heat.  Were it not for the low infrared transmissivity, the contents of
the greenhouse would simply heat up to the point that the energy of the
outgoing T^4 Stefan's Law radiation was sufficient to balance the
incoming solar short- and long-wave radiation.  Prevention of convective
removal would be irrelevant.  The only transmissivity spectrum for a
glass that I was able to find in a short Google/Yahoo search shows 80%
transmissivity in the visual spectrum and a broad minimum of 10%
transmissivity in the near-infrared spectrum for high-redox Solextra
glass from PPG, Inc. [American Ceramic Society Bulletin, Vol 84, No. 1,
p. 35].  The heat that can't get back outside the greenhouse warms the
contents including the air and the glass not only blocks the long-wave
radiation but prevents convective removal of the heat. End JSD comment]

And yes, you are correct. It was Arrhenius who introduced this false
analogy.

[JSD comment: And Rainer introduced his false analogy.]

Stewart:

A look from the moon back to earth reveals the overwhelming influence
which cloud coverage has on the variability of its albedo - or rather
the all-decisive spectral absorptivity-to-emissivity (alpha-to-espilon)
ratio, a source of variability which to my knowledge has been neglected
entirely by 'greenhouse-forcers' until recently. 

For recent discussions (or "fossil-fuel-industry-funded pseudoscientific
disinformation") of non-anthropogenic sources responsible for this cloud
variability see: 

Carslaw K S, Harrison R G, Kirkby J, Cosmic rays, clouds, and climate.
Science 298(2002)1732-1737

[JSD comment: The Abstract of Carslaw et al and the paper itself make
clear the speculative nature of their suggestions.

Abstract:  It has been proposed that Earth's climate could be affected
by changes in cloudiness caused by variations in the intensity of
galactic cosmic rays in the atmosphere.  This proposal stems from an
observed correlation between cosmic ray intensity and Earth's average
cloud cover over the course of one solar cycle.  Some scientists
question the reliability of the observations, whereas others, who accept
them as reliable, suggest that the correlation may be caused by other
physical phenomena with decadal periods or by a response to volcanic
activity or El Nin~o.  Nevertheless, the observation has raised the
intriguing possibility that a cosmic ray-cloud interaction may help
explain how a relatively small change in solar output can produce much
larger changes in Earth's climate.  Physical mechanisms have been
proposed to explain how cosmic rays could affect clouds, but they need
to be investigated further if the observation is to become more than
just another correlation among geophysical variables.

This abstract is perhaps the densest concentration of subjunctive mood
in the English language since Shakespeare -- 'proposed', 'could',
'intriguing possibility', 'may help explain', 'proposed to explain',
'could affect', 'need to be investigated further', and 'become more than
just another correlation'.  One admires the carefulness of the authors'
claims and should apply similar care in citing the paper.

Some mainstream commentary on the solar/cosmic ray/cloudiness hypothesis
can be found by going to  www.realclimate.org , clicking on Archives,
and searching on "cosmic".  This will turn up several threads discussing
the papers advancing this hypothesis.  End JSD comment]

Harrison R G, Stephenson D B, Empirical evidence for a nonlinear effect
of galactic comics rays on clouds. Proc. R. Soc. A (2006-01-18)
published online

Finally, regarding internal sources. : Geothermal heating alone is good
for about 0.2 Kelvin-per-year 'geothermal-forcing' of atmospheric
temperature - with huge error margins (Araki T, et al., Experimental
investigation of geologically produced antineutrinos with KamLAND.
Nature 436(2005)499-503). What do greenhouse-forcers assume regarding
its uncertainty (and variability?)?.

[JSD comment:  I think rather than huge error margins, we have fairly
large geographical variability.  I don't suppose you are suggesting that
geothermal heating was INCREASING sufficiently during, say, the 20th
century to account for any significant fraction of the 0.6 K increase in
Earths' average surface temperature.  I suspect it hasn't increased at
all on century time scales. I think climate modelers assume that the
goegraphic variability of geothermal heating gets carried around the
world by wind and ocean current and completely smoothed out on any time
scale of interest.  end JSD comment]

Best regards, Rainer 

   <snip>

Best regards.

Jim Dukelow
Pacific Northwest National Laboratory
Richland, WA 
Jim.dukelow at pnl.gov

These comments are mine and have not been reviewed and/or approved by my
management or by the U.S. Department of Energy.