Laboratory measurements of the infrared absorption of carbon dioxide using an FT-IR spectrometre suggest that the radiative forcing for CO2 doubling must be much less than assumed by climate scientists until now. A reduction factor of 80 is likely.

The main debate on Hug's spectroscopic experiment -
Dr Roy Spencer                        (USA)
Emma Daly                               (Australia)
Dr Jarl Ahlbeck                         (Finland)
Dr Hartwig Volz                         (Germany)
       Dr Jarl Ahlbeck                  (Finland), (responding to Dr Hartwig Volz)
       Peter Dietze                       (Germany), (responding to Dr Hartwig Volz)
Prof Paul S. Braterman              (USA)
Dr Heinz Hug                            (Germany), (responding to above review comments)
Mark Schoeberl                         (USA)
       John Daly                          (Australia),  (responding to Mark Schoeberl on `Web Publishing')
Prof Roland List                        (Canada)
Renato Quiñones                      (Chile)
Dr Jarl Ahlbeck                         (Finland)
Dr Hartwig Volz                        (Germany) (responding to Heinz Hug and Peter Dietze)
Prof Paul Braterman                  (USA)
Jack Barrett                              (Britain)
Curtis Covey                             (USA)         (commenting on Hug's paper)
Peter Dietze                             (Germany)  (in reply to Curt Covey)
Richard Courtney                      (Britain)       (response to Paul Braterman)
Jack Barrett                             (Britain)        (Disputes claims by Paul Braterman)

The second debate on Web Publishing and Peer Review
Prof Paul Braterman               (USA)
Dr Heinz Hug                          (Germany)
Mark Schoeberl                       (USA)
John Daly                               (Australia)
Dr Jarl Ahlbeck                       (Finland)
        Mark Shoeberl                (USA) (Responding to John Daly)
Dr Theodor Landscheidt          (Canada)
        Manfred Mueller              (Germany) (Responding to Mark Shoeberl)
Prof Paul Braterman               (USA)
       John Daly                       (Australia) (Responding to Paul Braterman)

Subject: RE: Spectroscopic sensation
Date: Wed, 5 Aug 1998 10:46:55 -0500
From: "Spencer, Roy" <Roy.Spencer@msfc.nasa.gov>
To: Hartwig.Volz@rwedea.de, "'091335371-0001@t-online.de'" <091335371-0001@t-online.de>
CC: (large mailing list)

Peter:
Thanks for making available the interesting paper by Hug. I certainly applaud any critical examination of even our most strongly held scientific beliefs. However, in this case, I think the conclusions of this paper can not be supported. Here is why:

It appears Hug bases his conclusions on the opacity of the whole atmospheric column in one of the CO2 absorption bands (around 15 microns). What he has neglected is the VERTICAL DISTRIBUTION of the change in radiative processes due to a doubling of CO2. For instance, the strong upper stratospheric cooling (peaking near 2 mb) in response to increasing CO2 would, by itself, require warming at some lower level in order to maintain radiative balance, even if the entire atmospheric column is essentially opaque. This upper level cooling (observationally documented by Kokin & Lysenko, 1994, J. Atmos. Terrest. Phys., pp. 1035-1040) and lower level warming is a common feature of all greenhouse atmospheres that are subjected to increasing greenhouse gas concentrations. The equilibrium temperature change at any specific level (including the surface) can NOT be determined by intuition. It requires time-dependent radiative transfer calculations throughout the entire atmospheric profile. This has been performed by many people (including ourselves).

Of course, the nature of the vertical distribution of temperature change also depends upon feedbacks, which are ignored in this whole discussion. I believe that feedbacks still remain the area of largest uncertainty about how the tropospheric temperature profile will change in response to CO2 increases.

-Roy

Roy W. Spencer
Senior Scientist for Climate Studies
NASA/MSFC/GHCC
977 Explorer Boulevard
Huntsville, Alabama 35806
Fax: (205)922-5788
Voice: (205)922-5960

Subject: CO2 Absorbance
Date: Fri, 7 Aug 1998 06:31:52 -0700 (PDT)
From: Emma Daly <emmadaly@yahoo.com>
To: daly@vision.net.au

Hi Dad,

Just read that paper you sent me.

Essentially the chemistry is correct.

The only major problem I have with the paper which wasn't really made clear was that the Beer-Lambert law which he used to determine the molar extinction coefficients is only valid up to 0.01M of CO2 or 440ppm. At higher concentrations it is not necessarily true.

Secondly this work was done in a lab in controlled conditions so Spencer's points are valid. You can not necessarily assume what is occuring in a 10cm glass vessel is valid in an atmospheric column. He is assuming a temperature and absorbance distribution in the atmosphere will remain constant. That is not a fair comparison between a static and dynamic system.

Emma

---
Emma Daly
Ian Wark Research Institute
University of South Australia
Adelaide, S.A., Australia

Subject: Re: Spectroscopic sensation
Date: Sat, 8 Aug 1998 19:03:30 +0300 (EET DST)
From: Jarl Ahlbeck AT <jahlbeck@ra.abo.fi>
To: daly@vision.net.au (John Daly)

Hello John,

I read the comment of Roy Spencer about the spectroscopic sensation, he may be right.

In the stratosphere there is no water vapour, and the influence of carbon dioxide might be significant, as it can be in very dry regions, say Siberia at winter night (and Finland too at winter night). The diurnial difference has decreased, and that might be because of increased carbon dioxide. But no general warming has occured, and that points towards zero net feedback from vater vapour (I really cannot believe in significant positive feedback !) The stratospheric cooling would require a slight warming to maintain the energy balance, but this GW must be very small compared to that projected by significant positive water vapour feedback.

The "spectrospcopic sensation" is based on experiments performed in a tube containing a substantial amount of water. I think these experiments are OK, but the conclusions drawn may not be correct.

Regards    Jarl Ahlbeck

---
Jarl R. Ahlbeck D.Sc.(Chem Eng.)
Research Associate,
Abo Akademi University, Finland

Subject:  AW: Spectroscopic sensation
Date:      Tue, 11 Aug 1998 14:11:13 +0200
From:     "Volz, Dr. Hartwig" <GPRHV@rwedea.de>
To:          "'John Daly'" <daly@vision.net.au>, 091335371@t-online.de
CC:        (large list)

Dear John,

please find attached my discussion of the Hug draft paper.   For your information I attach excerpts of a letter which I wrote in a context similar to Hug’s publication in November 1997.

Greenhouse physics based on absorption considerations alone are meaningless and the corresponding conclusions are wrong.  Funny enough, I learned only a few weeks after having written this letter of the corresponding contribution of Braterman (citation [7] in the Hug draft paper), who invented the same “perpetuum mobile” as described below and who uses the same physical arguments as in my letter,
though in different wording. Having had some correspondence regarding this subject already in the past, I am not overly optimistic that a “normal” natural scientist will ever understand greenhouse physics without
studying energy transfer by radiation. Nonetheless, this contribution is another attempt to put some
contrarians on a higher level of understanding on the learning curve.

As Braterman writes: “However one may view the debate over global warming, .... (my addition: Hug’s)
argument is not a useful contribution to that debate.”  The radiative and anthropogenic forcing calculations in the IPCC reports have been verified by me and are basically correct. There do exist quite some good
physical arguments against established IPCC climatic science, but these arguments are more sophisticated than those put forward by Hug.

Quote
It seems to me that my understanding of greenhouse physics is completely different from yours. I would like to remind you of the well-known method to measure the temperature of flames. A zirconium dioxide lamp (black body radiator) is placed behind a flame and the black body radiance is measured by a spectrometer through the flame. If the temperature of flame is lower than the lamp's, you will see absorption lines in the black body spectrum. If the flame is hotter, you will see peaks on the black body spectrum at the same wave number positions; if the temperature of lamp and flame equal each other, you will see the ideal black body spectrum.

A similar experiment: in the spectrum of the sun you see Fraunhofer lines (absorption lines). During an
eclipse you see emission lines in the chromosphere at the very same wave numbers of the Fraunhofer lines. In both experiments thermodynamics and quantum mechanics are closely interconnected. If you replace the hot lamp by the black radiator earth and the excited states in the flame by the vibration/rotation of gases in the atmosphere, you are in the correct greenhouse physics.

A summary of the correct physics is given in this figure:

For example, if you climb into a balloon and measure from an altitude of 100 m to ground, the measured
spectrum would be case 3, not something similar to case 1. I know from experience that this is hard to digest for many scientists. Nonetheless, from a thermodynamic and quantum mechanics point of view it is trivial.  With low energy sources (like earth) you are not allowed to consider absorption without taking emission into account. Greenhouse physics cannot be understood by absorption alone, but by both, absorption and emission of the gaseous phase, which both are mathematically described by radiative transfer equations. In the above spectra in all cases the transferred energy is the integral of the shaded areas. Please note that in case 3 no energy is transferred at all. A statement like “everything that can be absorbed, will be absorbed within a few hundred meters above ground” is bluntly wrong in greenhouse physics. Naturally in spectroscopy, with high energy sources, this is different. That’s why spectroscopic results have to be transferred with caution into greenhouse physics considerations.

I attach spectrums of the original publication of Hanel et al. (Journal of Geophysical Research, 77, 1972, p. 2629/41) that are very close to case 3 (Greenland) and to case 2 (Antarctica; in fig. 12d the air in the sinking whirl is warmer than the ground) as well as to case 1 (North Africa).

I would like to close this letter with my invention of a "perpetuum mobile" (thermodynamic paradoxon). In an evacuated black room hangs a hollow ball, with walls transmissable to infrared radiation and filled with CO2.  If something similar to my case 1 happened (absorption without emission and/or complete absorption within a few meters of the gaseous phase), the gaseous phase would warm by the radiation of the outer black wall and you could, for example, create electricity with a Peltier element between (cooler) outer black wall and (warmer) inner gas phase. Unfortunately, if case 3 was correct, you couldn't.
Unquote

Best regards

H. Volz

Dr. Hartwig Volz  -  Labor Wietze  -  RWE-DEA AG  -  Industriestr. 2  -
D-29323 Wietze
Tel: ++49 5146 89230  Fax: ++49 5146 89275  e-mail:
Hartwig.Volz@rwedea.de

Subject: comment to Dr. Hartwig
Date: Thu, 13 Aug 1998 11:48:20 +0300 (EET DST)
From: Jarl Ahlbeck AT <jahlbeck@ra.abo.fi>
To: daly@vision.net.au (John Daly)

Hi John,

I had some doubts about that the Hug's conclusions were against the second law of thermodynamics, and Dr. Hartwig's letter pointed out that the second law of thermodynamics is valid also for radiative heat transfer. Of course no radiation can be absorbed by a gas of the same temperature as the radiating surface. But in fact, the temperature of the air and of the surface are never the same, the air might be colder (absorption dominating) or hotter (emission). The greenhouse effect should occur at higher, colder levels and the influence of water vapour is essential.

Although the radiative calculations used by the IPCC might be basically correct, the modeler must have some view of the atmospheric water distribution and I don't think anybody can model the complicated connections between evaporation, condensation,convective heat transfer, radiative heat transfer, clouds, water content a.s.o. They may not even know enough about the influence of the composition of the atmosphere on the radiative properties.

What we can learn from this discussion, is that it may be a good idea to perform more laboratory experiments using modern spectroscopic equipment and realistic temperatures for the "black body" source and the temperature, pressure and chemical composition of the absorbing/emitting gas. We have seen too much of computer simulations, probably using garbage input....

regards, Jalle

---
Jarl R. Ahlbeck D.Sc.(Chem Eng.)
Research Associate,
Abo Akademi University, Finland

From: Peter Dietze
Fax to: Dr. Hug 0611-543301, Dr. Sundermann 0721-683446

Dear Dr. Volz, Sept 03, 1998

your comment of Aug 11 at http://www.microtech.com.au/daly/hugdebat.htm regarding Dr. Hug's spectroscopic draft paper /artifact.htm needs some clarification. You wrote "Greenhouse physics based on absorption considerations alone are meaningless and the corresponding conclusions are wrong". Right, within the 15 µm band that we are considering here, there are two independent - for a given atmospheric temp profile - processes: absorption and emission. Both result in the net radiative transport. The (omnidirectional) emission of CO2 (N2 and O2 are inactive) depends on the layer temperature.

I have no doubt the cases 1-4 in your figure 1 are correct. And your two examples with the circonium dioxide Nernst lamp radiating trough a flame are correct as well. In our case the earth surface (warmed by solar short wave radiation) is the IR radiator and the CO2 within the cooler air is the absorber of the 15 µm band. In this case Braterman's CO2-filled glass ball (held in the atmosphere) will be warmed - and this is neither a perpetuum mobile nor does it contradict Hug's or Barrett's essential conclusions about absorption (which to call 'not a useful contribution to that debate' seems quite impertinent and unscientifical).

Moreover I find it obscure that you and Braterman got to assert that their conclusions would lead to a warming of the glass ball in the isothermic case 3, thus creating a thermodynamic paradoxon. In this case *no* radiative transport (comparable to an IR beam) exists and thus no absorption! You seem not being aware that Hug clearly said, a zero bias measurement (i.e. thermal background radiation) was subtracted and only the signal ratio I/Io has been measured. Your conclusion that his absorption is arbitrary and mainly caused by the high temperature of his source (and will go towards zero if the source temp will hardly differ from the environment) is completely out of reality.

You say "if you climb into a balloon and measure from an altitude of 100 m to ground, the measured spectrum would be [the isothermal] case 3, not something similar to case 1". This is a sheer unproved assumption of yours and cannot hold as the air has definitely to be cooler than the ground (otherwise no net radiation within the 15 µm band will leave upwards). If your assertion would be right, we could extrapolate the same for the next 100, 500, 1000 m and so on - and finally absurd Hanel's satellite measurements (your figure 2)!

"A statement like 'everything that can be absorbed, will be absorbed within a few hundred meters above ground' is bluntly wrong in greenhouse physics" is your essential issue - which cannot be accepted in this way. Suppose we have a given atmospheric temp profile. Then the emission along the temp gradient will be acc. to Stefan-Boltzmann and be independent of the absorption. The absorption of the emission from ground - correctly measured by Heinz Hug - will be done to 99.94% within the first 10 m. If we double CO2 the same absorption will be within 5 m. As the troposphere is well mixed and the absorbed amount of energy is mostly unchanged, the temp profile (and thermal emission and radiative transport) should be mostly unchanged as well. Whether Jack Barrett's thermalization of the 15 µm band takes place or not, has hardly any influence as the back-radiation is thermalized by the earth in any case.

You believe (as IPCC, Sir John Houghton, Joos, Mitchell and Bengtsson) that the 1.2 degC temp increment for CO2 doubling at the upper troposphere (or lower tropopause) will be 'beamed' down to near ground by *adiabatic* parallel shifting of the atmospheric temp profile. I do not deny that adiabatic processes exist for convection, but the temp gradient is to my opinion essentially caused by radiative transfer and eddy mixing. We have never observed the air cooling down to -18 degC when it doesn't move or moves laterally only. So your assumption has to be rejected. In spite of being expressively asked in my mails to explain how the 1.2 degC get down to near ground, you never answered to this problem. Jack Barrett has asked Sir John the same question - and he couldn't answer. The fact is, we live on ground and it is of entire indifference whether the upper troposphere warms by 1.2 degC or whether the stratosphere cools or warms. Roy Spencer is right - the problem of tropospheric temp profile change for CO2 doubling cannot be solved by intuition, but only by a sophisticated computation of averaged radiative transport, taking into account evaporation, precipitation, clouds, various feedbacks, vertical mixing, winds, day/night and different latitudes and seasons - a nearly unsolvable task.

To "verify" IPCC's forcing you practically used the same simple radiative model based on satellite measurements and the assumption of broadening edges of the absorbed 15 µm band. This is not verification, but recapitulation! Your absorption area that broadens logarithmically for CO2 doubling, is proportional to the temp difference between ground and tropopause though the IR absorption is a property of the gas column and hardly depends on temperature - and definitely not on the -53 degC at the bottom of the absorption gap. Probably you mixed absorption and radiation, thus overlooking that the atmospheric 15 µm radiation into space *increases* (and not decreases) for doubling - which will compensate for absorptive warming.

So far I know you got a doubling sensitivity of about 1 degC mainly because you curbed the feedbacks (similar to Richard Lindzen). But you never solved the radiative transport equations! Btw. even the "advanced" MPIM Hamburg didn't (see Cubasch/Santer/Hegerl in Phys. Bl. 51, 269 (1995) 4 and the ECHAM3 model documentation that you can load down in postscript from http://www.dkrz.de/forschung/reports.html). So the near ground warming is more or less "best guess" - as Tom Wigley in 1992 honestly called IPCC's 2.5 degC in Nature 357. You claim to know the "correct greenhouse physics" - then what about Lindzen who only got about a quarter of IPCC's radiative forcing and one eigth of their doubling sensitivity? See Proc. Nat. Acad. of Sciences 94, 8335 (1997) 8. Why do you try to "verify" IPCC's warming though observations clearly show that it is by far exaggerated?

To me it seems obscure that IPCC has not documented all about their radiative model - for years we are trying in vain to get a proper basic paper from adequate members of the community. Their practice was to hide model details and create scientific facts and majority consensus by repeated quotation of results that originally have been based on assertions, assumptions and widely spread remarks in hardly accessible literature. The same holds for their carbon cycle: I never saw how they have converted the emission scenarios into future CO2 concentrations (in SAR chapter 11 their knowledge seems so poor that any proper calculation deems impossible). I got the impression, radiative warming is rather based on myths than on proved (and published) solid physics backed by near-ground measurements. So I appreciate that you are preparing such a paper though I think your approach is erroneous.

Peter Dietze

Phone&Fax +49/9133-5371 Email 091335371@t-online.de http://www.microtech.com.au/daly/carbon.htm (Carbon Model) http://www.wuerzburg.de/mm-physik/klima/cmodel.htm (Klima-Flop des IPCC)

Subject: Re: Spectroscopic sensation
Date: Tue, 8 Sep 1998 11:50:39 CST6CDT
From: "PAUL BRATERMAN" <psb@unt.edu>
Organization: UNT College of Arts and Sciences
To: 091335371@t-online.de, Paul S Braterman <psb@unt.edu>, 091335371-0001@t-online.de (P. Dietze)
CC: (large CC list)

Barrett's paper cited here with approval is erroneous, ignores an important term, and thus violates the second law of thermodynamics, as I have shown (Spectrochim Acta, '97).

The present contribution (unless and until it is accepted by a reputable journal, it should not be referred to as a "paper") appears to commit similar errors, and to ignore, or claim with no evidence to supersede, the voluminous experimental studies on the spectrum of carbon dioxide.

Are we being faced with yet another media pseudo-event?

Paul S. Braterman,
Regents Professor of Chemistry,
Department of Chemistry,
Masters Hall (Avenue C and Sycamore),
University of North Texas,
Denton, TX 76203

psb@unt.edu Tel: 940-565-2357, fax 940-565-4824

(This email is also included with the `Web Publishing' debate here - Ed)

Subject: Re: Spectroscopic sensation
From: Dr Heinz Hug
To: John Daly

Dear John, Sept 14, 1998

Re the contributions of Prof. Braterman and Dr. Volz, I want to point out that they accuse me for not taking the emission into account. Their approach (and IPCC's) is based on spectral satellite measurements and the assumption of broadening absorption slopes for CO2 doubling from which the area and thus the radiative forcing is derived. In this way the increased emission is not taken into account at all! Neither does the 'standard atmosphere' measurement cope with the night (the measurement was taken during day and clear sky). Moreover downwards to ground we have the cloud impact and variation of the atmospheric temperature profile that needs solving the radiative transport equation, as Roy Spencer correctly mentioned (he said he solved it - his result would be of interest).

To my knowledge these points has not been considered. So I wonder how Dr. Volz "verified" IPCC's radiative forcing - their figure must be flawed in the same way! Moreover Volz and Braterman erroneously assume, I inferred an absorption (and thus a perpetuum mobile) for the isothermal case 3. As Peter Dietze correctly mentioned, the thermal background radiation has been kept out of my calculations that are based only on the 'signal' ratio I/Io - which does not depend on the temperature of the source. Without source I is zero and the absorption is zero as well.

I determined the molar absorption coefficient which is a sort of constant, a gas property that has nothing to do with emission. I used this to integrate the broardening absorption edges for CO2 doubling in the atmosphere and to determine the ratio of the additional absorption to the existing one. In a second step I applied this ratio to the existing radiative forcing for CO2 of 32 W/m² that was determined by IPCC and Dr. Volz (who claims using correct greenhouse physics). For the 15 µm band I got a forcing of 1/80 of 4.3 W/m² for doubling. If he and Prof. Braterman say this result is wrong, they implicate i) my measurement is wrong and/or ii) my extrapolation to the whole atmosphere is wrong and/or iii) their forcing is wrong.

I did not (need to) determine the radiative flux which certainy depends on emission as well - so the discussers should not argue this to be a deficiency.

So far I know, the German DLR Institute for Atmospheric Physics (see http://dv.op.dlr.de/op_zentrum.html and http://dv.op.dlr.de/NE-PA/) got interested in the matter and they intend to take spectral measurements at different height from aircraft. Only then Dr. Volz will definetely know what spectra are measured above ground. I think these are extremely important because (within the 15 µm band) satellite measurements only show the IR emission emerging from the stratosphere. Possibly the 15 µm peak is flawed by collisions with other molecules. Fig. 12d presented by Dr. Volz, showing the antarctic emission spectrum, is supporting this. The emission temperature of the peak is essentially higher than that of the ice on ground.

Re Emma Daly's contribution: Certainly the Beer-Lambert law has its limits of validity. But it can be used for concentrations >400 ppm for a small thickness of the measured probe. Nonlinearity occurs for decadic extinctions >2. Analytic chemistry will not go beyond E=3. My probe was 10 cm only and for 714 ppm and 15 µm, E was 0.06. The extinction coefficient 20.2 m^2/mol that I took from the calibration curve and applied onto the whole atmosphere, yields E =2080. This means an extremely small transmission that in reality can never be measured.

Re Prof. Braterman claiming that my paper should not be regarded as a 'paper', I feel this was rather pretentious. Most papers only receive anonymous peer review, the motivations, misunderstandings, errors and bias of the reviewers being open to question. My paper is being reviewed at Daly's website and then gains acceptance or rejection in an open discussion by any scientist interested in the details of the experiment that I performed. To my mind this is a superior way for scientific literature to proceed. Papers - specially those nonconforming with the mainstream - should be published freely without the (often prohibitive) censorship implied in peer review, carried out by a few arbitrarily selected persons.

(Above paragraph also included with the `Web Publishing' debate here - Ed)

I heard your site is soon heading to 100,000 accesses, my congratulation! Peter Dietze who is forwarding this response of mine by email, told me he has now informed 800 people about the discussion and my paper that you made available at http://www.microtech.com.au/daly/artifact.htm. I am thankful for all the assistance and discussions and hope, more essential contributions and arguments will come in.

Sincerely, Dr. Heinz Hug

Wiesbaden, Germany,
September 13, 1998
Fax +49/611-543301 or contact Peter Dietze <091335371@t-online.de>

Subject: Comment to Dr. Hartwig
Date: Thu, 13 Aug 1998 11:48:20 +0300 (EET DST)
From: Jarl Ahlbeck AT <jahlbeck@ra.abo.fi>
To: daly@vision.net.au (John Daly)

Hi John,

I had some doubts about that the Hug's conclusions were against the second law of thermodynamis, and Dr. Hartwig's letter pointed out that the second law of thermodynamics is valid also for radiative heat transfer. Of course no radiation can be absorbed by a gas of the same temperature as the radiating surface. But in fact, the temperature of the air and of the surface are never the same, the air might be colder (absorption dominating) or hotter (emission). The greenhouse effect should occur at higher, colder levels and the influence of water vapour is essential. Although the radiative calculations used by the IPCC might be basically correct, they modeler must have some view of the atmospheric water distribution and I don't think anybody can model the complicated connections between evaporation, condensation,convective heat transfer, radiative heat transfer, clouds, water content a.s.o. They may not even know enough about the influence of the composition of the atmosphere on the radiative properties. What we can learn from this discussion, is that it may be a good idea to perform more laboratory experiments using modern spectroscopic equipment and realistic temperatures for the "black body" source and the temperature, pressure and chemical composition of the absorbing/emitting gas. We have seen too much of computer simulations, probably using garbage input....

regards, Jalle

---
Jarl R. Ahlbeck D.Sc.(Chem Eng.)
Research Associate,
Abo Akademi University, Finland

From: schom@zephyr.gsfc.nasa.gov (Mark Schoeberl)
Re: Spectroscopic sensation

Having looked at the paper and the responses, including the response by Dr. Hug, I think that there are good reasons to dismiss this paper as incorrect and poor science. Pushing a paper like this onto the open web for debate among non-technical experts before a thorough peer review smacks of political motivation and moves us away from seeking the truth - which should be the goal of scientific study and debate. The argument (by Hug) that the peer review system would not give this paper a fair shake is specious. The peer review system is essentially honest and has worked well over the last 150 years. Those that criticize the peer review system are usually those whose "scientific" findings cannot be supported or justified (e.g. creationists). The practice of web publishing (and including statements like "sensational") prior to review reduces the credibility of this research. I am sorry you have done this.

- Mark Schoeberl

(This email is also included with the `Web Publishing' debate here - Ed)

Dear Peter,

Many thanks for the information about the CO2 upheavel. I have passed it on to friends within IAMAS. I will look at the webpage once I am back in Toronto from the Utah desert.

All the best

Roland SG IAMAS
Roland List
Dept. of Physics, Univ. of Toronto
Toronto, Ontario, Canada, M5S 1A7
Prof.Roland.List@atmosp.physics.utoronto.ca

Dear Dr. Dietze:

Thanks very much for the information regarding the paper "The Climate Catastrophe - a spectroscopic artifact?". The article is extremely interesting.

Best regards,

Dr. Renato Quinones
Member of the JGOFS SSC
Uni of Conception,
Chile
Renato Quiñones <rquinone@udec.cl>

Subject: Hug report, continuing comment
Date: Fri, 18 Sep 1998 13:35:14 +0300 (EET DST)
From: Jarl Ahlbeck AT <jahlbeck@ra.abo.fi>
To: daly@vision.net.au (John Daly)

This is to continue the comment I sent earlier today: P.S. A description of the etablished way of calculating the radiative mechanisms of the atmosphere and the temperature profile can be found in the book by

Goody and Young "Atmospheric Radiation, Theoretical Basis" 2. ed., Oxford Univ. Press, 1989. Calculating the profile acc. to these equations gives a global surface temperature of 350 K (77 deg. C).

I remember that Lindzen has mentioned that the modellers simply have put in the correct temperature profile (15 deg C at the surface) and claimed that they have performed a "convective adaption", and then went on by using the same radiative equations to calculate radiative forcing......

So much for that science.

regards. Jalle

---
Jarl R. Ahlbeck D.Sc.(Chem Eng.)
Research Associate,
Abo Akademi University, Finland

Subject: WG: Hug paper; Hug and Dietze comment
Date: Fri, 18 Sep 1998 12:52:09 +0200
From: "Volz, Dr. Hartwig" <GPRHV@rwedea.de>
To: "'daly@vision.net.au'" <daly@vision.net.au>

Comments to Mr. Dietze,

having read the final version of the Hug paper as well as some comments, it seems appropriate to me to discuss some elements of radiative transfer and radiative forcing in the context of the statements and opinions put forward by you both. It is my conviction that greenhouse physics and radiative forcing cannot be understood without some basic knowledge in energy transfer by radiation.

To start with: You dislike my example "if you climb into a balloon and measure from an altitude of 100 m to ground, the measured spectrum would be case 3, not something similar to case 1" and you continue: "This is a sheer unproved assumption of yours and cannot hold as the air is definitively cooler than the ground...". Actually for this balloon example the calculations of radiative flux, CO2 radiative forcing and anthropogenic forcing are pretty simple, so let me calculate it.

Assumptions 1. Earth temperature 288 K, in thermal equilibrium with the air (as, for example, after sun set). 2. The temperature gradient in the atmosphere can be measured and may amount to e.g. 0.5 K / 100 m, i.e. the temperature around the balloon is 287.5 K.

Hug states correctly that one has to apply the radiative transfer equation according to his citations [11] and [12] in order to calculate this (or any other) example. Unfortunately he does not apply it, but considers only the sink function (absorption) without taking the source function (emission) into account.

Calculation of radiative flux The primary source is earth with 288 K. The radiation is calculated with the Planck equation, which is temperature dependant. My computer tells me that at 15 µm (667 cm(E-1) wave number) the radiation is 0,1309328 W / (m² * sr * cm(E-1)). (sr = steradiant, by definition 65.6 ° room angle). Hug calculates correctly that in an altitude of 100 m the radiance originating from the primary source is practically zero. The term sa (Hug calls it "absorption coefficient") in the radiative transfer equation is contained in both parts, the sink function and the source function (so it might as well be nominated "emission coefficient"). Full absorption at 15 µm implies fully developed emission, so the air around the balloon radiates at the corresponding wave number with the same energy as a black body of 287.5 K, which is 0,1302387 W / (m² * sr * cm(E-1)). This radiation is completely neglected by Hug.

At 15 µm Hug calculates a transmission value of 0.6 per mille after only ten meters. His text and his figures want to make believe, or he may believe himself, that this is the actual radiation going into the upper atmosphere. The actual radiation measured by the man in the balloon in an altitude of 100 m, however, is still 99.47 per cent of the original value of the primary source earth. Somewhat frivolous I had claimed in my first contribution that radiation would be unchanged, which is a rough approach and not precisely correct. But who was closer?

In your contribution you also commit a serious mistake in this context, by writing "Suppose we have a given atmospheric temperature profile. Then the emission along the temp gradient will be acc. to Stefan-Boltzmann and be independent of the absorption." A gaseous phase does not emit acc. to Stefan-Boltzmann (which is a black body emission over the entire black body spectrum), but according to the radiative transfer equation. If the absorption coefficient is zero, e.g. at 11 µm (909 cmE-1), then also the emission coefficient and thus emission will be zero. For example at 11 µm earth of 288 K emits with 0.096383 W / (m² * sr * cm(E-1)). The man in the balloon, measuring to ground, will precisely measure this same value. When he turns his instrument into the zenith during night, he will measure the energy to be attributed to the temperature of space, i.e. zero energy. Conclusion: Forget about Lambert-Beer on its own, forget about Stefan-Boltzmann, use radiative transfer equations with Planck function and Lambert-Beer together and nothing else in greenhouse physics.

It is not by chance that I have opened my first contribution with two illustrations of Kirchhoff's law (measurement of the temperature of flames; Fraunhofer lines). Kirchhoff's law was postulated in 1859 and has never been experimentally falsified since then. Theoretically it can be shown that any deviation of Kirchhoff's law would violate thermodynamic rules such as they are generally accepted. The flux calculation presented here is a trivial application of Kirchhoff's law. It seems absurd to me that a scientific institution (the German DLR Institute for Atmospheric Physics) should try to verify once more Kirchhoff's law by spectral measurements over ground from aircrafts (Dr. Hug: "so far I know" and "only then Dr. Volz will definitely know what spectra are measured above ground."). These spectra are predictable with elementary physical tools, as demonstrated here.

Calculation of CO2 radiative forcing The radiative forcing value in the air column between the ground and the observer in the balloon corresponds to the loss (difference) in energy of the radiative flux at the lower and upper end of the 100 m air column. For the width in wave number of 1 cm(E-1) the forcing is (0.1309328 - 0.1302387) = 0.000694 W / (m² * sr) or, integrated over a room angle of 180°, 0.00218 W / m². For the band absorber/emitter CO2 it has to be integrated over the entire band width of the 15 µm-band. From precision spectroscopic measurements offered or cited elsewhere [e.g. in the IPCC report "Climate Change 1994 - Radiative Forcing of Climate Change (remark: sorry for that, this is the interesting part) and an Evaluation of the IPCC 1992 Emission Scenarios (this is the poor part)", Cambridge University Press, 1995] it can be shown that is has to be integrated over round about 180 cm(E-1), of which results a 15 µm-band forcing of roughly 0.4 W / m² over the 100 m air column. Making the same type of calculation over many atmospheric layers and adding up over the height of the entire atmosphere, total forcing amounts to round about 38 W / m². (My personal calculation. It has to be noticed that with increasing altitude pressure and thus optical density of CO2 decrease. That is why the width of integration over the 15 µm-band decreases with increasing altitude.) Hug cites with approval "the possible maximum greenhouse effect occurs within a 100 m layer near ground", whereas the calculation reveals an effect of slightly more than 1% only for this layer. You may judge on your own whether or not this cited statement is "a useful contribution to that debate" (the greenhouse debate).

Calculation of anthropogenic forcing Assumptions: CO2-concentration doubles. Temperature gradient remains constant, thus the air around the balloon is still 0.5 K warmer than the ground. (The second assumption is not trivial. But I would like to keep it simple).

In addition to radiative transfer considerations the main reason for the existence of an anthropogenic greenhouse effect is a spectroscopic one. To start with some qualitative statements, most scientists familiar with infra red spectroscopy know about the following. 1. IR active gases have an absorption/emission band structure, not a line structure 2. With increasing concentration of the IR active gas the band structure becomes wider 3. With decreasing concentration the band structure becomes more narrow 4. At sufficiently high concentration the band is "saturated" in the centre 5. IR absorption spectroscopy uses high energy (hot) black body sources and determines e.g. the concentration of trace gases with the aid of the sink function of the radiative transfer equation 6. IR emission spectroscopy uses high energy (hot) gases as sources (for example flue gas) and determines e.g. the concentration of trace gases with the aid of the source function of the radiative transfer equation 7. In absorption spectroscopy "saturation" means that "everything that can be absorbed will be absorbed" (you have heard about that) 8. In emission spectroscopy "saturation" means that "everything that can be emitted will be emitted" (which might be somewhat new to you).

Back to the observer in the balloon. In the initial situation most of the CO2-band width (as mentioned, a width of round about 180 cm(E-1)) is saturated. From spectroscopic precision measurements (see citation above) it can be shown that the band will widen by rather precisely 15 cm(E-1) when the CO2-concentration is doubled. Thus the original forcing over the first 100 m of the atmosphere will increase by roughly 100 * 15 / 180 = 8.3 %, which is the additional (anthropogenic) forcing caused by doubling of CO2. Again this calculation has to be carried out over many layers and added up over the entire atmosphere. An important feature is that the optical thickness of CO2 and thus the band width will decrease with increasing altitude, whereas the widening of the band by CO2-doubling will always stay at about 15 cm(E-1). That is why with increasing altitude the anthropogenic forcing becomes relatively more important as compared to the original forcing value. Integrated over the entire atmosphere, I calculate an increase in forcing by CO2-doubling of 11 % or 4.2 W / m² for the 15 µm-band, which is close to other published values. Whatever the value of a more precise and numerically fine-tuned calculation might finally be; Dr. Hug's conclusion "a reduction factor of 80 is likely" is wrong. It goes without saying that one cannot expect to calculate a quantitatively correct number from a qualitatively incorrect physical model.

Concluding remarks - Having read for years some literature about the greenhouse effect, with laymen as well as scientists as target group, it seems justified for me to state that frequently one reads quite some scientific oddities in this context. There are additional errors in Dr. Hug's paper, reflecting some of these oddities. The objective of this communication was to concentrate on the prime misconception in the context of radiative forcing. I do not intend to discuss peripheral subjects raised in your contribution now or later. Feeling as contrarian by preference, none-the-less I feel as scientist in the first place. I do like good science, I dislike poor science, whatever the result may be.

Sincerely

Hartwig Volz

Dr. Hartwig Volz - Labor Wietze - RWE-DEA AG -
Industriestr. 2 - D-29323 Wietze
Tel: ++49 5146 89230
Fax: ++49 5146 89275
e-mail: Hartwig.Volz@rwedea.de

Subject: Re: Climate predictions
Date: Sat, 19 Sep 1998 21:21:25 CST6CDT
From: "PAUL BRATERMAN" <psb@unt.edu>
Organization: UNT College of Arts and Sciences
To: MUELLER.ICS@t-online.de CC: "P.Dietze" <091335371-0001@t-online.de>, John Daly <daly@vision.net.au>, Paul S Braterman <psb@unt.edu>, Hartwig.Volz@rwedea.de, roy.spencer@msfc.nasa.gov, Peter.Die@facstaff.cas.unt.edu

To avoid misunderstandings, I am not a "NASA guy", though NASA funds part of my work (in a very different area). I am NOT being paid by anyone for my contributions, such as they are, to the debate on climate. I am NOT a climatologist, and only find myself in this debate because of my rebuttal of Barrett's work.

I made the following points:

1) Barrett's work is thermodynamically unsound, and therefore any work that quotes it with an approving flourish should be regarded with circumspection

2) A claim that everyone to date has got the spectroscopy wrong should be submitted to the discipline of careful and, so far as such a thing is possible, impartial examination before being publicly trumpeted as a "sensational discovery".

3) We have had a media pseudo-event with a pseudo-paper which found its way into the mail box of everyone in my own Department and indeed many others, formatted to resemble a PNAS paper. There is the risk that excessive self-promotion could lead to similar episodes, which discredit science. For this reason, I now only refer to items accepted by journals as "papers".

I stand by these points.

You raise the issue of money; I assume you know of the existence of a "global climate change" lobby, dedicated to discrediting the IPCC and all its works, which is fully funded by the fuel industry, and that Shell and BP have withdrawn from this group. These events were reported as they happened in Chem & Eng News, the house organ of the American Chemical Society.

You criticize current climate models; I cannot comment on this, except to say that every improvement in these models for the past ten years seems to have broadened the consensus that anthropogenic global warming is already most probably under way.

I thank you and other readers (if any) for your time; at this point, I feel that I have made my contribution, and will leave further debate to others.

Sincerely,

Paul Braterman

Paul S. Braterman,
Regents Professor of Chemistry,
Department of Chemistry,
Masters Hall (Avenue C and Sycamore),
University of North Texas,
Denton, TX 76203

psb@unt.edu
Tel: 940-565-2357,
fax 940-565-4824

(see John Daly's response here)

Subject: Reactions to the Hug paper etc
Date: Sun, 18 Oct 1998 16:09:35 -0400
From: Jack Barrett <100436.3604@compuserve.com>
To: John Daly <daly@vision.net.au>

Comments on paper by Dr. Heinz Hug

In view of the recent comments about my ability to violate the laws of thermodynamics and the refusal of Prof. Braterman even to acknowledge my letters to him (Dr. Volz does reply, but seems to ignore the re-statement of my position) I should begin by making some comments on my original paper [J. Barrett, Spectrochimica Acta, 51A, 415, (1995)].

The paper was about the 1992 version [Houghton, J. T.,Callander, B. A., and Varney, S.K., eds. Climate Change 1992, Cambridge University Press, p. 7, (1992)] of the IPCC mechanism of global warming which was described entirely in terms of radiative transfer. "Some of the thermal radiation is absorbed by radiatively active gases in the atmosphere.... The absorbed energy is re-radiated in all directions...such that the radiation that is lost to space is from higher, colder levels ....". Later on there is the assertion "Increases in the concentrations of greenhouse gases will reduce the efficiency with which the Earth cools to space and will tend to warm the lower atmosphere and surface." Having heard about convection currents which transport energy and water vapour from the surface to the cloud-tops and knowing that when the Sun shines that the lower atmosphere warms caused me to look further into the physics.

McIlveen's admirable textbook [McIlveen, R., "Fundamentals of Weather and Climate", Chapman & Hall, (1992)] informed me that "the atmosphere is almost completely opaque in substantial parts of the spectrum... and the atmosphere is really very opaque indeed to the wavelengths strongly absorbed by water vapour and carbon dioxide and that a layer only 30 m deep contains enough carbon dioxide and water vapour to absorb all terrestrial radiation" [apart from that exiting through the 7.5 - 13 micron window]. So far, so good.

Then I read that "radiant energy emitted by the Earth's surface... will be completely absorbed by the first 30 m of air, warming first the molecules of water vapour and carbon dioxide, and then almost immediately sharing this heat with the surrounding air molecules." Great! But then came the statement "by Kirchoff's law, water vapour and carbon dioxide must emit these same wavelengths with the same efficiency as they absorb them; in fact a layer deep enough to be opaque must emit as a black body at the layer temperature." This statement surprised me as I was under the impression that Kirchoff's law applied accurately to condensed phase surfaces. In the Appendix to Chapter 8 this impression was confirmed with the additional statement that "water vapour and carbon dioxide have very complex lines and bands of lines... which arise from quantized staes of molecular rotation and vibration." What disturbed me was the statement that "Kirchoff's law applies throughout" [the atmospheric system]. "There is enough [water] vapour and carbon dioxide to make the lines merge." The conclusion is that the lower atmosphere approximates to a black body absorber and emitter. Now, depending upon the resolving power of the spectrometer used, it can be observed that the line/band structures of water vapour and carbon dioxide are intact and do not merge to any significant extent. If the pressure of a radiatively active gas is sufficiently low then its constituent molecules will, in a quantized manner, absorb and emit characteristic quanta with equal probability. At the high pressure of the lower troposphere collisional deactivation of excited states must contribute significantly to the redistribution of the absorbed terrestrial radiation. Otherwise the air would not warm up in the daytime.

The proponents of radiative transfer theory make the approximation that emissions from water and carbon dioxide molecules can be modelled by the use of the Einstein B coefficient which, in effect, is Stefan's law in which the emission is entirely a function of temperature and independent of the chemical nature of the absorber/emitter molecule. The spectral characteristics of water and carbon dioxide are built into the model by including their absorption coefficients at all wavelengths concerned and by assuming that the absorptivity is identical to the emissivity.

In my paper I included the assertion that "such an assemblage of gaseous molecules cannor radiate energy over a continuous range of wavelengths as would a cavity [i.e. a black body] with the same temperature." This has been misinterpreted by Prof. Braterman, Dr. Volz and the IPCC [Houghton, J.T., Meira Filho, L.G., Callander, B.A., Harris, N., Kattenberg, A., & Maskell, K., (eds), Climate Change 1995, Cambridge University Press, (1996)] as indicating that I believe that no emissions from water and carbon dioxide molecules are possible. Letters to them have been ignored and have led Prof. Braterman and Dr. Volz to their fantasies about violations of the thermodynamic laws.

Any misunderstandings of the physics have been thoroughly dealt with by my correspondence with Sir John Houghton [Spectrochimica Acta, 51A, 1391, (1995)] and Keith Shine [Spectrochimica Acta, 51A, 1392, (1995)]. My replies [Spectrochimica Acta, 51A, 1395, (1995)], the first of Prof. Braterman's conjectures about the thermodynamic laws [Spectrochimica Acta, 52A, 1565, (1996)] and its refutation by Richard Courtney [Spectrochimica Acta, 53A, 1601, (1997)] amplify the debate.

I have placed my current position in an adjoining contribution on this web-site (I hesitate to call it a paper, maybe an electronic phenomenon would be better) and it would seem that Dr. Hug, with his careful observations, has come to the same conclusion that I did, that virtually all the initially emitted terrestrial radiation (apart from that sailing through the window) is absorbed by the lower part of the atmosphere. What this means is that the rate of warming of the lower atmosphere will be unaffected by an increase in carbon dioxide partial pressure. Even Sir John agrees with this.

In his criticism Sir John begins his argument by stating that I "assert that the absorption and emission of radiation in the atmosphere ... can only occur effectively if the collisional deactivation time of the relevant molecular vibrations is substantially longer than the radiation lifetime." We agree on this point. What Sir John inferred was that because of this that I conclude that greenhouse warming is negligible in the lower atmosphere. I included the above assertion to argue that significant emissions occurred in the upper atmosphere, again a point about which there is no disagreement.

Both Sir John and Keith Shine point out that the surface temperature of the Earth depends upon the rate of cooling of the atmosphere in addition to the rate of warming. Again, we agree completely and I express doubts about the accuracy (i.e. is the prediction of 2 K accurate?) and precision (i.e. what are the error limits of the 2 K?) of the values produced for the enhancement of surface temperature when the carbon dioxide partial pressure doubles.

The theory of radiative transfer is fully described by Goody and Yung [Atmospheric Radiation, Oxford University Press, (1989)], but from there to the IPCC's latest prediction of a 2 K increase if carbon dioxide doubles its partial pressure lie many approximations and uncertainties. Wentz and Schabel [Nature, 394, 661, (1998)] have identified a systematic error in the satellite temperature measurements of the lower troposphere. Roy Spencer and John Christy have posted their reactions to this on their web-site. The error due to the ever-decreasing altitudes of the satellites has been welcomed by Hansen et al., [Science, 281, 930, (1998)] who regard the satellite data as "the refuge of those who deny the reality of global warming." I resent this implication that groups of scientists are selective in their choice of observations upon which to base their conclusions. The IPCC surely would not do that? The sea-change in the global warming debate that Hansen et al., desire will only come about when all the errors in the satellite and terrestrial temperature records have been properly assessed and those of the temperature changes arising from the various models have also been computed.

I have yet to be convinced that more atmospheric carbon dioxide leads to a retardation of cooling of the upper atmosphere. It is asserted [J. T. Houghton, Global Warming—the Complete Briefing, Lion Publishing, (1994)] the average altitude of emission is increased to a region of lower temperature where collisional activation of the radiatively active gases would be lower leading to a lower rate of cooling and thence to an overall warming of the atmosphere (the rate of warming being constant). Certainly, at lower temperature (~3.3 K per 500 m), the collision rate is reduced, but by no means as much as to offset the larger number of radiative molecules.

With regard to what should be called a paper my opinion is that the web-debate is beneficial to the outsiders who otherwise have to run the gauntlet of Editors who take upon themselves a role of filtering potential papers and the referees which they choose who are most likely to be insiders. In any such debate the scientific principles will always win in spite of the vested interests represented. My own experiences at having papers published in the scientific journals are varied. I have had papers rejected by editors without them being subjected to the refereeing process and I have had papers turned down by referees. I don't approve of the former process, but accept the latter as it is normal practice. What I find odious is that some sympathizers of the IPCC have caused the powers that be at Imperial College to forbid me to use the College affiliation on my publications—hows that for free and above-board scientific debate?

Jack Barrett

Subject: CO2 radiative forcing
Date: Wed, 21 Oct 1998 16:13:50 -0700
From: covey@rabbit.llnl.gov (Curtis Covey)
To: 091335371@t-online.de (Peter Dietze)
CC: covey1@llnl.gov, mmaccracken@usgcrp.gov, rlindzen@mit.edu

Dear Dr. Dietze,

Thanks for a stimulating paper. It got me to dig an old notebook on radiative forcing out of my garage.

As an IPCC lead author, I believe I have a responsibility to respond to serious questions about global warming. Dr. Hug seems to be genuinely puzzled at his results.

Although I'm no expert on radiation transport, I did a little work on the subject ten years ago. As I recall, the value of ~4 Watts per square meter for doubled CO2 ultimately derives from a long series of laboratory measurements, e.g., as published by D. K. Edwards in the Journal of the Optical Society of America (v. 50, p. 617, June 1960), which were later fitted to empirical formulas by V. Ramanathan (Journal of Quantitative Spectroscopy and Radiative Transfer, v. 12, p. 933, May 1972; Journal of the Atmospheric Sciences, v. 33, p. 1330, 1976). I notice that these papers were not referenced by Hug. Perhaps he could have a look at them and compare with his results. The number 4.3 is not too precise -- in fact I've heard that it will be revised downward to 3.8 -- but I find it hard to believe it's really as low as 0.054. (I think Lindzen's "5% of 32" accounts for convection in a way many of us find dubious, but in any case that number involves a separate consideration.) I don't understand what Hug means by "sum of slope integrals," so I can't say why his results are so different from previous laboratory work. Maybe the problem involves extrapolating from 357 and 714 ppm CO2 in a 10-cm cylinder up to the full atmospheric column amounts.

If you and/or Hug wish to discuss this matter further, let me know.

Sincerely,

Curt Covey covey@pcmdi.llnl.gov http://www-pcmdi.llnl.gov/ covey/resume/cchome.html

Subject: Re: CO2 radiative forcing
Date: Fri, 23 Oct 1998 09:55:33 -0700
From: 091335371-0001@t-online.de (P. Dietze)
Reply-To: 091335371@t-online.de
To: covey@rabbit.llnl.gov (Curt Covey)
CC: mmaccracken@usgcrp.gov, rlindzen@mit.edu, daly@vision.net.au, Jack Barrett <100436.3604@compuserve.com> Fax: Dr. Heinz Hug 0611-543301

Dear Dr. Covey,

thanks for your cooperative message of Oct 21 which I have faxed to Dr. Hug who is not online.

Indeed we are puzzled about the huge discrepancy to the IPCC radiative forcing that so far could not be cleared up. Our problem is that obviously IPCC has not prepared a reference paper where the whole story of their basic parameter is documented in a comprehensive way.

We are in contact with two German researchers, Prof. Raschke from GKSS Institute for Atmospheric Physics (Raschke@gkss.de) and Dr. Volz from RWE/DEA oil labs (Hartwig.Volz@rwedea.de) who say IPCC's figure is correct. Dr. Volz has verified it by taking satellite-measured spectra as base, determining the present absorption area (39 W/m^2 for 180º steradiant) and a hypothetic slope broardening for CO2 doubling which he derived as 49 x log2 = 14.8 cm^-1 and thus getting an increment of 11-12%. The broardening he got from the original "Sum of linestrengths" triangular graph with the 15 µm peak that is shown in IPCC 1994 on page 175.

Prof. Raschke who had written an effective algorithm for the radiative transfer from tropopause via troposphere to ground, that is in use for the MPIM ECHAM3 model in Hamburg, supports Dr. Volz. As he seems to agree about the lacking IPCC documentation, he is now preparing a paper about radiative forcing (and transfer, I suppose), but no details leaked out so far. Dr. Volz is going to publish his paper (in German) soon. His contributions to our discussion you find at http://www.microtech.com.au/daly/hugdebat.htm (after the microtech server disk crash has been repaired).

These two (and Keith Shine and Paul Braterman who are in opposition to Jack Barrett) are objecting that Dr. Hug has not coped with the emission of CO2. So far I know the IPCC figure stems from integration of absorption line strengths from HITRAN (?) spectra, computed for tropopause conditions i.e. 1/10 density, 250 K and theoretical doubling. Nobody has ever mentioned that a CO2 doubling even means a doubling of 15 µm band radiation into space (radiative cooling!).

Indeed Hug's beam-measured absorption is too high because the beam is scattered and any re-radiation effects (thermalized or isofrequent) mostly go aside instead of 50% reaching the detector. This is why I had suggested, a mirrored and heat-insulated tube should be used. But I think, this will not yield the huge difference.

As you supposed, that may be because he considered the decadic extinction for the whole atmosphere whereas IPCC operates within the (thin and cold) tropopause only. And here the "Barrett effect" - thermal collisions with O2, N2 and H2O molecules - which disseminate and thermalize the 15µm absorption (shifting it out of the band and sharpening the peaks), are essentially less than under near-ground conditions.

On the other hand Hug has really measured the spectrum for CO2 doubling whereas the other ones are merely analytic. Moreover we don't know so far whether the used HITRAN (?) spectra are from plain CO2 gas or mixed in a realistic atmosphere, which may cause a great difference in the slope absorption.

> I don't understand
> what Hug means by "sum of slope integrals," so I can't
> say why his results are so different from previous
> laboratory work. Maybe the problem involves
> extrapolating from 357 and 714 ppm CO2 in a 10-cm
> cylinder up to the full atmospheric column amounts

To explain this I append his Fig.2 which I have corrected (as he is not so familiar with computer graphics). You see, he only adds up the difference in absorption line strengths for doubling from a point lower than extinction 10^3 for the 1*CO2 case.

So far I know, Jack Barrett is preparing a comment for John Daly's web site. Dr. Hug will comment after we identify the clou for IPCC's factor 80. Any support from you (or other colleagues) are very appreciated. I suggested Heinz to make another PC evaluation for the first 100m layer and possibly another measurement at simulated hight (low density and temperature) to identify the Barrett effect which is known in literature, but which IPCC has not coped with.

Best regards, Peter Dietze

Phone&Fax +49/9133-5371 Email 091335371@t-online.de

Subject: A False Assertion
Date: Fri, 2 Apr 1999 19:12:20 +0100 (BST)
From: Richard Courtney <richard@courtney01.cix.co.uk>
To: "John L. Daly" <daly@vision.net.au> CC: Jack Barrett <100436.3604@compuserve.com>

Dear John:

In the debate concerning Heinz Hug's paper published on your web site, Paul Braterman asserts;

"Barrett's paper cited here with approval is erroneous, ignores an important term, and thus violates the second law of thermodynamics, as I have shown (Spectrochim Acta, '97)."

This assertion of Braterman is false. I published a refutation of his misunderstanding in a subsequent edition of the same journal; ref. Courtney, RS: Spectrochimica Acta, vol.53A, 1601 (1997).

It is - at best - disingenuous to assert that one "has shown" something when what one "has shown" has been demonstrated to be an error.

All the best

Richard

Subject: Braterman attack
Date: Mon, 5 Apr 1999 12:45:39 -0400
From: Jack Barrett <100436.3604@compuserve.com>
To: Onar Aam <onar@con2.com>, Sallie Baliunas <baliunas@cfa.harvard.edu>, Roger Bate <101627.2464@compuserve.com>, Sonja Boehmer-Cristianse <sonja.b-c@geo.hull.ac.uk>, boettiger <boettiger@wiesbaden.netsurf.de>, Nigel Calder <nc@windstream.demon.co.uk>, John Christy <christy@atmos.uah.edu>, Richard C <richard@courtney01.compulink.co.uk>, John Daly <daly@vision.net.au>, Hartmut Damrau <hartmut@netcom.com>, Peter Dietze <091335371-0001@t-online.de>, "E.S.Posmentier" <eposment@titan.liunet.edu>, John Emsley <j.emsley@ic.ac.uk>, Franz Gerl <gerl@Theorie.Physik.UNI-Goettingen.DE>, Vince Gray <vincegray@xtra.co.nz>, Heuseler <Klimabrief@aol.com>, Angela Kelly <angela.kelly@which.net>, Krahmer <Krahmer@t-online.de>, Mueller <Mueller.ics@t-online.de>, "R.Bartlett" <r.bartlett@virgin.net>, Tom Segalstad <t.v.segalstad@toyen.uio.no>, Fred Singer <ssinger1@gmu.edu>, Willie Soon <wsoon@cfa.harvard.edu>, Roy Spencer <roy.spencer@msfc.nasa.gov>, Robert Stevens <snevets@execpc.com>, Henrik Svensmark <hsv@dsri.dk>, Robin Vaughan <r.a.vaughan@dundee.ac.uk>, Hartwig Volz <Hartwig.Volz@rwedea.de>, Gerd-Rainer Weber <gvst_URE.weber@t-online.de>, "C. Wiin-Christensen" <fkomet@post7.tele.dk>, "O. Wildgruber" <OWildgruber@csi.com>