Comments and reviews on the above paper are collected below.

Subject: Radiative Forcing paper - final version
Date: Thu, 20 Apr 2000 12:46:35 +0200
From: "Bert Bolin" <bert.r@osteraker.mail.telia.com>
To: <091335371@t-online.de>

Dr Dietze,

Please, delete me from your address list. Your meessages have so far not provided me with new meaningful information

Bert Bolin

Subject: Radiative Forcing paper - Intermediate questions
Date: Thu, 20 Apr 2000 13:51:37 -0600
From: Chick Keller <cfk@lanl.gov>
To: Jack Barrett <100436.3604@compuserve.com>, 091335371-0001@t-online.de (P. Dietze), Fred Singer <ssinger1@gmu.edu>

Peter and Jack,

I've been asking some radiative transfer people here at the Lab about your arguments and we may have some clarification questions for you soon.

But it did occur to me that I could understand your points better if you could tell me how your model would deal with the atmosphere of Venus where there is a monstrous greenhouse effect raising surface temperatures some 500°C above what an airless body would see.

If I understood your conclusions they were that collisional deexcitation and optical saturation would limit the effect of CO2 such that it would be restricted to a close surface effect and would not increase much with increasing CO2 concentrations. Venus would seem to be a test of those conclusions.

Regards,

Charles "Chick" F. Keller,
Institute of Geophysics and Planetary Physics/University of California
Mail Stop MS C-305
Los Alamos National Laboratory
Los Alamos, New Mexico, 87545
cfk@lanl.gov
Phone: (505) 667-0920 FAX: (505) 665-3107
http://www.igpp.lanl.gov/climate.html

Subject: Radiative Forcing paper - Intermediate questions
Date: Sun, 23 Apr 2000 05:18:54 +0200
From: p_dietze@t-online.de (P. Dietze) Reply-To: 091335371@t-online.de
To: Charles F Keller <cfk@lanl.gov>

Dear Chick,

you wrote

You didn't catch my conclusions correctly. The collisional deexcitation is not essential as half of the absorbed energy has to be re-radiated to ground direction anyway. I did not say that optical saturation would limit the effect of CO2 - except for a certain wavenumber range. The doubling effect at the fringes is always quite the same, no matter what starting concentration (or layer thickness) you consider. I even replicated the IPCC forcing of 3.7 W/m².

My essential reductions come from water vapor overlap in the lower troposphere, less vapor feedback, cloud coverage and by not transmitting the warming of the upper atmospere 1:1 down to the ground (constant lapse rate), but by proper application of Stefan-Boltzmann's law near ground.

Not at all. The Venus atmosphere has 90 bar, mostly sulfur acid and CO2 and is by no means comparable to Earth. So far the reasons for the heat on Venus are not cleared up. A physicist told me, it cannot be due mostly to the greenhouse effect. Venus may be emitting considerably more energy (may be from a former huge impact and/or from being younger) and so the heat insulation by the extremely dense atmosphere could considerably raise the ground temperature. It does not make sense to pull out the Venus to back global warming belief or to doubt a reasonable radiative model of the Earth atmosphere. The question is only whether our physics (applied on known Earth conditions) are correct - I doubt, Venus can be useful to question HITRAN, Lambert-Beer, Planck and Stefan-Boltzmann.

Best regards,    Peter

Subject: Radiative Forcing paper - Intermediate questions
Date: Sun, 23 Apr 2000 02:30:26 -0400
From: "Onar Aam" <onar@con2.com>
To: Peter Dietze <091335371@t-online.de>, "Charles F Keller" <cfk@lanl.gov>

<Peter Dietze wrote:>

Ok, with 90 bar my calculation changes slightly. I assumed 1 bar. 90 bar should give 6.5 doublings or so more than my initial estimate of 11. As Roy pointed out Venus is closer to the sun and therefore should get 1/r^2 times more energy per area than Earth (r = Venus'/Earth distance to the sun). However, it's worth pointing out that due to the thick clouds very little sunlight actually penetrates to the surface.

Whether geothermal activity is a significant source of heat on Venus I cannot answer. On Earth geological fission is certainly an important factor in geological time scales (As Lord Kelvin demonstrated, our planet would be geologically dead without it!), but I am not sure how important it is to the Earth's day to day energy budget. Speaking of which, given that the Earth is one gigantic nuclear power plant, I'm curious as to whether -

1) it is worth taking into account in the climate models and
2) if so whether this already is being done.

Onar.

Subject: Radiative Forcing paper - Intermediate questions
Date: Sun, 23 Apr 2000 11:47:52 -0600
From: Chick Keller <cfk@lanl.gov>
To: "Onar Aam" <onar@con2.com>, <091335371@t-online.de>

Dear Onar,

Thanks for the points and questions. I'm right now just collecting ideas and data, no judgments.

One question though. Several people have referred to Venus as a "young" planet. What can that mean? Unless I missed something, it's just as old as the rest of the planets give or take a bit. And, if so, we need to explain why it's acting "young". Any help here?

Charles. "Chick" F. Keller,

Subject: Radiative Forcing paper - Intermediate questions
Date: Mon, 24 Apr 2000 08:13:19 +1000
From: "John L. Daly" <daly@vision.net.au>
To: Chick Keller <cfk@lanl.gov>

Dear Chick

you wrote:

The age of Venus is one thing. How long it has been in its present orbit is another question. Is it possible for a planet to be a `blow-in' from outside? Or a dislodged Jovian satellite or something? If so, that would explain Venus being old and yet behaving young.

Venus rotates backwards, ever so slowly. A day on Venus is almost like a year here. I don't know what such a slow rotation would have on a planet's climate, but I would'nt like to be on the daylight side.

Venus also has no magnetic field, so it gets the full brunt of corpuscular bombardment from the sun, a secondary energy input.

Venus has no large tilt angle and therefore little precession. This would prevent any Venusian equivalent of our `ice ages' (speaking very relatively of course)

The topography of Venus was shown by satellite radar sweep to have vast lava flows etc. So geothermal activity is a possible real factor here and may go part of the way to explain the high temperature (465°C)

In short, an astronaut landing on Venus would find himself asphyxiated by the carbon dioxide atmosphere, burned to a crisp by the searing heat, poisoned by the acid rain, and crushed by the super-dense atmosphere. That's why goddesses are vest viewed at a distance :-)

Chick, I hope that your original assumption that it was 1 bar is not the same assumption being made by others who are quick to compare Earth with Venus. It's well known in Astronomy that Venus has a super-dense atmosphere of almost pure CO2. The atmospheric pressure there is 90 times ours. Since we only have 0.036% CO2, whereas Venus has 98% CO2 in an atmosphere with 90 times our pressure, that means Venus has 2,500 times our density of CO2, or 5.5 times our CO2 for every extra degree of temperature.

I don't think Venus can possibly be used as a surrogate comparison with Earth. The baseline parameters are so horrendously different to make all such comparisons meaningless.

Regards

John Daly

--
John L. Daly
"Still Waiting For Greenhouse"

Subject: Radiative Forcing paper - Intermediate questions
Date: Sun, 23 Apr 2000 19:10:30 -0400
From: "Onar Aam" <onar@con2.com>
To: John Daly <daly@vision.net.au>, "Chick Keller" <cfk@lanl.gov>

No that was my assumption, and I explicated it because I suspected that it was wrong. But as my calculations show, 90 bar or 1 bar doesn't really make that much of a difference on Venus.

Wrong. You forgot to multiply by 90 bar. The CO2 concentration on Venus is 98/0.037*90 = 240,000 times greater than on earth. While seemingly impressive this corresponds to a puny 18 doublings.

Actually nearly 50 times our CO2 for every extra degree of temperature, but this is irrelevant given that forcing is not linear, but logarithmic with concentration.

I agree. The only thing we can say for certain is that the CO2 on Venus, despite its massive concentration, causes only a fraction of the greenhouse effect.

I guess the only useful thing we can learn directly from Venus is that logarithmic forcing is a tricky thing. For instance, we know that in response to the end of the ice age, the CO2 level rose more than 50% over a very small time period. Thus, even though we humans have increased the CO2-level into unchartered territory we have yet to rival the percentage growth of CO2 at the end of the ice age. And after all it's the percentage growth that counts.

If the rise in CO2 was dramatic it was nearly rivaled by the dramatic plunge in CO2 that followed. The increased CO2 and the warmer climate lead to a dramatic plant growth which sucked out a lot of the new CO2 from the atmosphere (much like the effect we are observing right now, where a stunning 4 GtC is sucked out of the skies every year). CO2 levels dropped from 320 ppm to 270 in a short time. This change is as dramatic in magnitude as the increase we've experienced since 1900.

Onar.

Subject: Recent questions
Date: Mon, 24 Apr 2000 09:17:22 +0100 (BST)
From: richard@courtney01.cix.co.uk (COURTNEY)
To: daly@vision.net.au

Dear John:

I have been following the informative, interesting (and amusing) discussions concerning atmospheric compositions and volcanic heating as they pertain to the surface temperatures of Earth and Venus. And I write to disagree with your statement to Chick Keller when you said;

Sherwood Idso did the comparison in Section 4.2 of his book titled 'Carbon dioxide and Global Change: Earth in Transition' as long ago as 1989 (ref. Idso S.B., IBR Press). He plotted CO2 greenhouse warming vs CO2 atmospheric pressure for Earth, Mars and Venus using a log/log scale (his Figure 4.1) and obtained a straight line. (I observe that almost all data sets give straight lines when plotted log/log). He drew this line as a solid-line on the graph and calculated its equation to conclude:

The example I cite above demonstrates that Venus has been used as a surrogate comparison with Earth to provide a climate-forcing result that agrees with recent suggestions of 'climate sceptics' (e.g. Hug, Dietze, etc.). But various 'climate proponents have cited Venus as a surrogate to support their case.

John, I said I am writing to disagree with your statement that I quote above. My opinion of the matter is:

I think Venus is as useful a surrogate as many other proxies now often used for indication of atmospheric temperature as a function of atmospheric CO2 concentration. The comparison of Venus with Earth allows almost any assertion to be made concerning the importance of CO2 concentration to temperature and, therefore, it has similar value to most proxy studies of this relationship (e.g. tree rings, forminfera, bore hole temperatures, etc.).

Additionally, while writing, I take this opportunity to comment on a statement Chick Keller recently made to Nigel Calder when he wrote;

Chick's above statement is flawed for two reasons; i.e.

1. It lumps "all" global warming 'sceptics' together as saying the same thing, and I don't know of any time or climate issue where that has been true. One of the very few things that unites the 'sceptics' is their abhorrence of the IPCC's practice of seeking and proclaiming "consensus": the 'sceptics' are united in their opinion that this practice is an attack on the scientific method.

2. It is revisionist in that it asserts the opposite of recorded history. The 1995 IPCC Report did not provide aerosol cooling as a "significant new point": Pat Michaels (a 'sceptic' included in this circulation list) had made the point years before as an example of significant flaws in the models, and IPCC representatives then scoffed at it. Later, when passage of time had disproved the 'ocean-sink' excuse for non-warming, the modellers adopted the aerosol hypothesis as an alternative excuse. Many 'sceptics' (including myself) ridiculed this change of excuse. A famous historian has lost everything this month because a UK law court proved he is revisionist; and this implies that IPCC supporters should be careful when making historical statements.

All the best      Richard

Subject: Radiative Forcing paper - Intermediate questions
Date: Mon, 24 Apr 2000 08:38:43 -0600
From: Chick Keller <cfk@lanl.gov>
To: John L. Daly <daly@vision.net.au>

Dear John,

Thanks for the parsing of my questions. I am asking my planetary friends about Venus. I know a fair amount about its tectonic situation--apparantly it doesn't have plate tectonics as we know it--rock is too viscous due to lack of water in the minerals. It does seem to heat up so much inside that at times there is a complete turn over in of the surface. Other isolated features called "coronae" point to sporadic upwellings of a very different sort than seen on Earth. The planet seems to have been in its present orbit since the "beginning" and its strange rotation may be do to tidal interactions with the sun although I'm not clear about this and am asking - (recall Mercury is entirely phase locked to the sun as our Moon is to the Earth). The lack of magentic field could be a result of no rotation. Our dipole field is partly a result of the Earth's rotation (its caused by chaotic convection in the liquid core affected by coriolis force from the rotation--with normal orientation close to axis of rotation interrupted from time to time by a change in polarity with intermediate stages where the field is largely neither dipole nor aligned with the rotation axis--see publications by Glatzmaier et al in the last few years).

My original question was perhaps a bit naive, but to clarify, I was simply asking if Jack Barrett's and Peter Deitze's radiative transfer model could be used on Venus to predict its greenhouse effect. That the pressures and temperatures are very different didn't seem to me to affect their results, that collisional deexcitation and optical thickness would result in GH effect only near the surface and not increase with increasing CO2. I thought it was worth considering.

As to viewing goddesses from afar, I heartily agree!

Cheers,    Chick Keller

Subject: Recent questions
Date: Mon, 24 Apr 2000 08:54:58 -0600
From: Chick Keller <cfk@lanl.gov>
To: richard@courtney01.cix.co.uk (COURTNEY), daly@vision.net.au

Dear Richard,

Thanks for clarifying some points. However, it still seems to me that many (of course not all) GH critics took great exception to the aerosol models presented in the 1995 SAR asserting that the effect wasn't strong enough and was just a rationalization of the models' inability to reproduce the 20th century temperature record.

One point of note. You mentioned that ocean uptake was disproved, "Later, when passage of time had disproved the 'ocean-sink' excuse for non-warming, the modellers adopted the aerosol hypothesis as an alternative excuse."

To the contrary, have you seen the recent (March 24, 2000 Science) papaer by Levitus et al which seems to show rather clearly that the global ocean has indeed taken up much heat in the past 50 years (also recall the Warren White et al paper a year earlier seeing a similar effect). Both the paper itself and an highlight by Richar Kerr are very informative and should strengthen the non-equilibrium nature of the present warming. I note that perhaps serendipidously, but nevertheless accurately, the observed ocean uptake of heat is very close to what has been predicted by the coupled ocean/atmosphere general circulation models. Often people have challenged the models to make predictions that can then be observed. In this case, they appear to have made such a prediction.

Regards,   Chick Keller

Subject: Recent questions
Date: Mon, 24 Apr 2000 17:52:30 +0100 (BST)
From: richard@courtney01.cix.co.uk (COURTNEY)
To: Chick Keller <cfk@lanl.gov>

Dear Chick:

I take your point about the Warren White et al paper. I have not seen the recent paper by Levitus et al and I will look it up. However, I stand by my assertions that
1. warming has not been as great as was originally predicted (e.g. in IPCC 1990),
2. many GHG warming proponents claimed oceanic thermal uptake was responsible for this,
3. passage of time indicated that this claim was not correct, and
4. there would have been no need for the aerosol hypothesis if passage of time had shown the claim to be correct.

There must have been some oceanic thermal uptake, and White et al. quantified this. I have not yet seen the work by Levitus et al. (but I assume their finding is similar to that of White et al. because the aerosol hypothesis has not been abandoned).

I agree that, as you say, "many (of course not all) GH critics took great exception to the aerosol models presented in the 1995 SAR ... was just a rationalization of the models' inability to reproduce the 20th century temperature record". Indeed, I was - and I am - one who does not accept the aerosol hypothesis although not because "the effect wasn't strong enough". Indeed, it is too strong. I will summarise my view of why I disagree the hypothesis briefly as follows, but a more complete explanation is in my paper in 'Energy & Environment' vol. 10, No. 5 (1999).

The GCMs have coarse spatial resolution, and anthropogenic sulphur emission has short atmospheric residence time. Therefore, at any point in time, the modelled spatial distribution of the aerosol must approximate the spatial distribution of the sulphur emissions.

The total aerosol forcing is only known to an accuracy of about +/_ 400 per cent. However, if the aerosol forcing is responsible for the discrepancy between predicted and observed GHG forcing, then the total forcing of the aerosol must equal the discrepancy.

The GCMs that include the aerosol forcing include a distribution of negative forcing across the planet in a similar pattern to that of the sulphur emissions. The total negative forcing is set to correct for the discrepancy between the previously predicted and the observed GHG forcings. The used total negative forcing in the GCM makes the modelled mean global temperature agree with observed mean global temperature. Please note that the total negative forcing is chosen to create the agreement: other values of the total negative forcing (e.g. the median value, maximum value and minimum value) are not modelled.

Hence, the agreement between modelled and observed mean global temperature is fixed as an input to the model, and it is not a result of the model.

The pattern of predicted surface temperatures across the planet is the output of a GCM which includes the negative forcing from anthropogenic aerosol.

If the aerosol hypothesis were correct then use of the input negative forcing should cause a GCM to predict the history of temperature changes across the Earth's surface. But these models don't predict the observed history of such changes. For example, central Europe had the world's largest sulphur emissions through the twentieth century, and so it is not surprising that the Hadley Centre GCM predicts central Europe then had the world's greatest cooling. But observations indicate that central Europe had the world's largest warming through that time (N.B. the model predicts the world's GREATEST COOLING for the region of observed GREATEST WARMING).

The 'aerosol GCM' predictions of changes to historic temperature patterns show greater disagreement with observations than could be expected by random chance.

If the aerosol hypothesis were correct then the modelled and observed temperature pattern changes would agree. They don't, and this demonstrates that the aerosol hypothesis is not an explanation for most, if any, of the discrepancy it is being used to explain.

Please note that the predictions of 'global warming' are generated by the GCMs. It is discrepancy between those predictions and observations that we are discussing. And the GCMs themselves demonstrate that the aerosol hypothesis does not remove the discrepancy.

All the best    Richard

Subject: Radiative Forcing paper - Intermediate questions
Date: Thu, 27 Apr 2000 12:07:02 +0200
From: "Weber, Gerd-Rainer" <Gerd-Rainer.Weber@gvst.de>
To: "'Onar Aam'" <onar@con2.com>, daly@vision.net.au, Chick Keller <cfk@lanl.gov>

Dear all:

What is this thing about Venus and CO2? What makes (and made) the big difference in the evolution and present composition of planetary atmospheres is THE DISTANCE FROM THE SUN - even assuming that the planets formed from roughly the same material of the solar nebula. The primordial atmospheres of the terrestrial planets Venus, Earth and Mars were probably very similar; the present atmospheres evolved from degassing from the interiors and crusts of the planets and subsequent chemical evolution of the degassed material. No questions that you have different chemical reactions as you get closer to the sun, the difference in present chemical compositon and physical state of the atmospheres of the terrestrial planets is then to a large degree due to the distance to the sun (planetary mass, Jeans escape flux and so forth also play a role). But just as a reminder, Mars´ atmosphere also is about 95 per cent CO2, just like Venus, and it´s a hell of a lot colder there.

Greetings,

Gerd Weber, Essen, Germany

Subject: The significance of Venusian climate
Date: Thu, 27 Apr 2000 12:32:08 +0100 (BST)
From: richard@courtney01.cix.co.uk (COURTNEY)
To: "Weber, Gerd-Rainer" <Gerd-Rainer.Weber@gvst.de>

Dear Gerd:

Yes, you are right. Solar distance is of course important when considering thermal input to planetary atmospheres.

I hope you will forgive my failure to mention mention solar distance when I reported Idso's analysis to John Daly. Chick Keller had cited Venus as 'evidence' for the strong CO2 radiative forcing estimated by the IPCC, and I was claiming that the 'Venus argument' could also be used as 'evidence' to oppose that estimate. I illustrated my claim by citing Idso's analysis which provides a result that agrees with the estimates of Hug and Dietze, not IPCC. (Idso had published his analysis more than a decade before Hug and Dietze conducted their very different analyses). Perhaps wrongly, I did not think a detailed description of Idso's analysis was required but I provided a reference.

In response to your clear point, and in fairness to Idso, I should say that he did take account of solar distance in his considerations of Earth, Mars and Venus. He also included paleo-data for the Earth (a series of points at 500 million year intervals back to 3.5 x 10^9 years before present) on his graph, and they fit his 'straight line' for "CO2 greenhouse warming vs. CO2 atmospheric pressure". To obtain the data for his graph, he considered both the change to thermal ouput of the Sun with age (25% increase over the considered time period) and the change of received thermal flux with distance from the Sun.

I find it interesting that Idso, Hug and Dietze each evaluated CO2 greenhouse effect using very different methods, and they each analysed very different data, but they reach the same conclusion (i.e. approx. 0.4 deg. C increase to the Earth's mean global temperature for a doubling of the Earth's atmospheric CO2 concentration). This does not make them right, but it does demonstrate that the 'Venus argument' can be used to support claims of 'global warming sceptics'. Hence, the 'Venus argument' is not the clear support for the IPCC argument that Chick had asserted. Indeed, it is clear support for Hug and Dietze.

Thankyou for raising the point.

All the best    Richard

Subject: The significance of Venusian climate
Date: Thu, 27 Apr 2000 10:38:08 -0600
From: Chick Keller <cfk@lanl.gov>
To: richard@courtney01.cix.co.uk (COURTNEY), "Weber, Gerd-Rainer" <Gerd-Rainer.Weber@gvst.de>

Dear Richard,

With all due regard, if you reread my note (reproduced below), I made no such assertion. I simply asked if Peter's analysis could be applied to Venus and what it would get. One of the problems I see in much of what I'm reading from this list, is such unfounded attribution. People read too much into what has been written, and then go on to "quote" by paraphrasing what they assume the writer meant. I will include examples of this in my critique of John Daly's web site analysis of the IPCC's TAR second draft of Policy Makers' Summary where he interprets some of the text in a particularly interesting way.

Please reread carefully what has been written before you paraphrase it. I repeat, I never said Venus' atmosphere proved or disproved anything. I just asked if Peter and Jack could apply their work to it. Finally, if I fall into this same trap and misquote any of you, please point it out.

For clarity I reproduce my original note to Peter and Jack:

Charles. "Chick" F. Keller

Subject: The good ship Venus
Date: Thu, 27 Apr 2000 13:27:55 -0600
From: Chick Keller <cfk@lanl.gov>
To: Jack Barrett <100436.3604@compuserve.com>

Dear Jack,

Thanks for the reply to my slightly academic question. My comments appear below in the text in color.

First my current probably inadequate understanding of your point. If I understand from below and elsewhere the IR photon from the Earth's surface is absorbed by a CO2 molecule which collisionally deexcites before it can re-radiate. This seems to me to be no problem because by so doing the process heats the atmosphere. Since the mean free path for such IR radiation is probably very very short near the surface (and decreases with increasing concentrations of CO2), the heating will be local. However, some process, either conduction, convection or radiation carries heat upwards. If radiation, the the process is repeated again and again as we move higher in the atm. Net result is a GH heated atmosphere and surface. Similarly with conduction. But, if the additional heating near the surface is advected upwards in deep convective cells we get the familiar cumulo-nimbus features in which heat is lost by phase change, as well as the other processes. But since such features make up a very small fraction of the earth's surface and are limited in their temporal existence to fraction of a day, this can't be the major story. Thus, your mechanism should heat the surface and that heating should increase with increasing GHG while the quantitative heating of the troposphere above the PBM is very complex and needs complex models and good observations to be understood. So I can't see why you mechanism wouldn't result in GHG heating that increases with GHG concentration.

Dear Friends, I am asked to give m views about Venus. Venus is the morning and evening star (Elmer Gantry). Its brightness is due to the sulfuric acid clouds that have a high reflectivity. The IPCC use them on Earth to offset some of the warming that has'nt happened. Venus is a small planet a long way from Earth and I only have a small piece of paper with information about it. On Venus the sulfuric acid clouds completely close the infrared window that is open on Earth. As ZJ has pointed out Venus is a young planet, still cooling down I'm not sure what this means. No one has yet told me what they mean by "a young planet", and "still cooling down" is a statement without quantitative constraint. Given the convective and conductive nature of Venus, my planetary interior friends assure me that its geothermal flux is negligible. Finally are you saying that the reason Venus' surface is so hot is that sulfuric acid clouds block the IR wavelengths?. and has an atmosphere which is 96% carbon dioxide at a surface pressure of 90 atmospheres. It aint half hot there I don't understand this statement. It's extremely hot at the surface of Venus. Do I miss your point? and most of the lighter molecules have escaped to space and there will be losses of water and carbon dioxide occurring as well. All this kind of thing happened on Earth before Sir John took over and our early atmosphere of carbon dioxide largely dissolved in the new oceans and it began to rain and wash soluble salts into the rivers and oceans. Do you have any reference where people posit that Venus will follow the Earth's atmospheric history? It seems to me that its atmosphere is stable and that it will never make the changes you mention above.

The calcium ions combined with the hydrogen carbonate ions via help from some shellfishy friends to give us our stock of carbonate rock. When photosynthesis began the remaining carbon dioxide in the atmosphere (about the same as there is oxygen now) was made use of by the first cyanobacteria. Eventually the Earth became green as nearly all living matter became desperate to get into the act of making use of this new material and to grow. When humans came upon the scene they were also impressed by the power of carbon dioxide and they wanted some for themselves and they wanted more for the green things that they fed upon. What with all this scavenging its a wonder there is any carbon dioxide left. Its low level in pre-industrial days is rate limiting for some crops. Whoever is producing more carbon dioxide is helping green things to burgeon. Whether this is also causing global warming is what we are debating. In the last week we have had 15 cm of rain and there was certainly no sign of global warming here. Perhaps this is Sir John's revenge and is part of the positive feedback where more carbon dioxide warms us up and produces more water vapour which warms us even more and then since what goes up must come down it rains more. We could do with some of the negative rainfall which the modellers predict for some regions until they decided that this was unrealistic. Fancy negative rain, what would the umbrella designers do? What does all this have to do with applying your mechanism to the Venus problem? Given the Venusian surface temperature, there will never be liquid water at its surface.

Last word on Venus; its day (243 Earth days) is longer than its year (225 Earth days) and it spins clockwise. But forget about runaway greenhouses, concentrate on runaway theories that don't work. Now for the sunshine which sometimes occurs here. In the morning the sun shines upon us and the Earth feels the warmth. It radiates this warmth upwards and some ofit excapes through the IR window. The rest of it is absorbed by the water and carbon dioxide in the fisrt 100 m of the atmosphere. That's why the air warms up, I'm told. The absorbed radiation causes the molecules of water and carbon dioxide to vibrate more that they are accustomed to doing. They would dearly love to return to their ground states and would do so by re-emission if they had the time. But, in the congested lower atmosphere they bump into nitrogen and oxygen molecules who steal their energy from them. By doing a lot of this theft the whole bottom layer of the atmosphere warms up because the molecules are travelling more quickly (I had a message from Maxwell and Boltzmann about this). The point I have been trying to make for some years is this.

Radiative transfer is fine for blue skies, especially dry blue skies. But, there are other ways in which absorbed energy is transferred to the upper troposphere. The main route is by convection and we have had plenty of that this week. Once in the upper troposphere radiation rules, there is no other way. Now what we have to decide is whether extra carbon dioxide will alter this state of affairs. Are you saying that nearly all the excess energy at the surface is transported to the upper troposphere by convection? This might be true to get it out of the planetary boundary layer, but above that also? (see my initial comments above)

The arguments put forward by the IPCC and Peter, based upon extra absorption by hot bands allow two ways of calculating the possible outcome. When that is agreed upon there will then be the argument about the water feedback and that seems to be a large problem for the modellers who are divided 50/50 about whether the effect is positive or negative. Can you give me some references to papers where modellers argue that the water vapor feedback is negative? It is no problem for anyone who has lived alongside the tropical oceans. They know that the water feedback is negative and that it has a cooling influence. Go inland until this feedback disappears and really feel the heat. With all due respect, this well known effect has little to do with the radiative effects of increased water vapor in the atmosphere.

Now that Bob Watson did not like to agree with me about residence times although he clearly does, so he invents a non-scientific term in politician-speak to cover up his ignorance. He said the residence time for carbon diaoxide was 50-200 years. I said it was 5 years and that the half-lifetime for the return to equilibrium is 38 years and I stick by those figures. Not good enough for Bob though. He now says he was talking about the adjustment lifetime whatever that is. It is an IPCC word not to be found in any chemistry dictionary. It is a loose way of saying that if the recent increase in carbon dioxide stopped this very day that it would take several of my 38 year half-lives to return to the equilibrium value. It is not beyond his capabilities to mutliply 38 by three (say) to get to within his 50-200 years. Its the Braterman syndrome where you disagree with someone so you make up a statement of that person's views which that person does not hold and then criticise the person for holding them. Pathetic. That's enough, Happy Easter, Jack

It's interesting to read your disagreement with Bob Watson just above, but I was hoping for a discussion of application of your theory to Venus.

As to putting words in your opponent's mouth--there's a lot of that going around.

Regards, Charles. "Chick" F. Keller

Subject: The significance of Venusian climate
Date: Thu, 27 Apr 2000 22:26:53 +0100 (BST)
From: richard@courtney01.cix.co.uk (COURTNEY)
To: Chick Keller <cfk@lanl.gov>

Dear Chick:

I have again read your note and also your note of 20 April. I agree that I misunderstood your note of 20 April and that you did not make the assertion that I inferred from it. I offer my sincere apology for this. I hope you will accept that my error was a stupid mistake and not a deliberate misrepresentation of your words.

I am circulating this apology to all concerned in the - probably unobtainable - hope that this will go some way to correcting any damage I may have caused.

I am very sorry. I have no excuse, but I point out that in the past others have refered to Venus as a 'proof' that the IPCC estimate is correct (you have had a copy of at least one such assertion that was made to me) and I wrongly assumed that your note of 20 April was another example of this. I freely accept that it was not and that I made a false assumption.

I apologise.    Richard

Subject: The significance of Venusian climate
Date: Thu, 27 Apr 2000 11:55:58 -1000
From: George and Teresa Birchard <gfb@aloha.net>
To: Chick Keller <cfk@lanl.gov>

Dear Chick,

I think that before you ask Peter to model the CO2 greenhouse effect on Venus that you might provide him with a model that he could accept of the effect of H2SO4 clouds on the radiation budget of Venus. Would it be reasonable to ask those that propose aerosol caused cooling on earth to model Venusian sulfuric acid clouds? Clearly the clouds reflect radiation from the surface of Venus. Are the clouds contributing to the high surface temperature by blocking outgoing radiation?

It appears that Venus has an adiabatic lapse rate. Adiabatic compression to 90 bars makes a large contribution to the high surface temperature. A drive into Death Valley is a great way to get a feel for compressional heating. The surface pressure on Venus makes Death Valley look like paradise.

Obviously, the greenhouse effect contributes to the high surface temperature of Venus. However, I get the feeling that original reference to Venus in the context of Peter's model was really a disguised appeal to emotion. We don't know enough about Venus to model its radiation balance well. So, what's left? It leaves an appeal to emotion that CO2 is bad. I am concerned that much of the public discussion of the greenhouse effect is based on emotion, not reason. It's ok to have feelings and emotional responses to articles like Peter's. Maybe you have a gut feeling that he is wrong. I just think that there is a problem when the emotional and scientific arguments get mixed up by scientists. When the non-scientists get mixed scientific and emotional arguments from 'experts', results like the O.J. trial can be expected.

Maybe, I'm just sensitive to this problem after working on the nuclear waste research.

I am eagerly awaiting the analysis of Peter's model that your group will be providing.

Regards,    George

Subject: The significance of Venusian climate
Date: Thu, 27 Apr 2000 16:54:17 -0600
From: Chick Keller <cfk@lanl.gov>
To: richard@courtney01.cix.co.uk (COURTNEY)

Dear Richard,

No need to apologize. I have come to understand that you are careful and courteous and I value our interactions. Thus, I'd like to clarify my statement, that I did not mean to suggest you misrepresented my position on purpose. I merely used this as an example of a problem we all have from time to time of quickly responding in a well-meaning albeit inaccurate way.

No, no, our interchanges are very good and I continue to value them.

Best wishes,     Chick

Subject: Radiative Forcing Paper - Some Answers
Date: 7 May 2000
From: Peter Warlow
To: John Daly

There is a fallacy in Dietze's argument.

Take two identical planets; put soot into the atmosphere of one and snow into the atmosphere of the other, then switch off the Sun. The sooty planet cools quicker than the snowy planet. If, however, you use Dietze's argument, you would say that soot absorbs lots of the radiation from the ground and re-emits a lot back to the ground. Snow absorbs very little of the energy radiated from the ground, so re-emits little back to the ground. You would conclude that the sooty planet must cool down more slowly.

The temperature of a passive planet depends only on the solar input and the colour of the planet. The colour determines the input absorptivity and the output emissivity. A neutral-coloured planet, grey or white, has the same equilibrium temperature as a black body, for a given solar input. Relative to this, the Earth is only 9K warmer than expected. Part of this can be explained by the fact that there is more snow in winter, which reduces the emissivity but has no effect on the absorptivity.

Venus is 400K above expectations, which no colour can explain. It must be cooling down. The cooling rate is in the order of 1K per century. The surface solidified in the order of 30,000 years ago, and the planet is only in the order of 100,000 years old. Venus is giving us a re-run of Earth's history. It tells us nothing about Earth's future. The atmosphere of Venus did not produce the high temperature. The earliest high temperature state produced the dense atmosphere as the planet outgassed.

Peter Warlow

Subject: The significance of Venusian climate
Date: Thu, 11 May 2000 15:26:44 +0200
From: "Volz, Dr. Hartwig" <Hartwig.Volz@rwedea.de>
To: Chick Keller <cfk@lanl.gov>

Dear Chick,

you wrote:

The discussion of Venus or Mars in the context of earth's climate irritates me for years. One can read quite some oddities from promoters of the potentially dangerous greenhouse effect and of sceptics alike. This communication is meant to be a primer how to calculate or at least reasonably estimate Venus' ground temperature.

Astronomy, geothermal heat flow, Venusian heat flow

Basic facts about Venus and Mars are compiled in http://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html and http://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html

The data on these sites are compared with corresponding parameters on earth.

According to textbooks on astronomy it is generally assumed that the inner planets (Earth, Venus, Mars among them) are formed from the debris of a dying star (presumably a supernova explosion) some 5*10^9 years ago. On earth only a very few naturally radioactive mother nuclides (from potassium, rubidium, thorium, uranium) have survived this long time, all with half life times above 10^8 years. These nuclides and their daughter nuclides generate a geothermal heat flow of round about 0.2 W/m² on average, naturally unevenly distributed over the surface of earth. Because of the same astronomical origin it is safe to assume that the Venusian heat flow is in the same order of magnitude and thus negligible compared to the energy by insolation. (No "young planet", no impact whatsoever. Note that an impact would hit the outer planets Saturn and Jupiter with much higher probability because of their sheer size and gravity). This was stated correctly by your colleagues. Correct is also that the black body radiation temperature of Venus is lower than earth's, because of the higher albedo (see link venusfact).

Calculation of lapse rate, kinetic gas theory, basic thermodynamics

Basic thermodynamics of a planet with atmosphere can best be understood by an experiment of thought:

1. Imagine a planet-like star without rotation and with a nitrogen atmosphere, located in space without any short or long wave background radiation, and heated from the inside with 240 W/m². By Stefan-Boltzmann's law one calculates the surface temperature of the star to be 255 K (the famous temperature of earth without a greenhouse effect). But what is the temperature or temperature distribution of the atmosphere? Molecules moving upwards are slowed down by gravity (this means a cool-down in kinetic gas theory), those moving downwards are speeded up (which means a warming). By the movement potential energy (Epot) is transformed in kinetic energy (Ekin) of molecules and vice versa.

A more detailed analysis shows that also rotational energy (Erot) - in the case of molecules made up of 2 atoms - has to be taken into account. If you wait long enough, the atmosphere of the motionless star would be without motion by itself and its energy evenly distributed. You can write for the total atmospheric energy (Etot):

Any layer of the star's motionless atmosphere has the same energy Etot; but because Epot varies with altitude, also Ekin (i.e. temperature) varies with altitude. With some thermodynamical transformation you get from (1)

which is identical with the equation one finds in textbooks on meteorology for the dry (or sometimes called theoretical) adiabatic lapse rate. dT/dz is the temperature gradient of the atmosphere, g is the star's gravitational acceleration and cp is the specific heat of the atmospheric gas at constant pressure (in this example cp incorporates the sum of Ekin and Erot). Applying this knowledge to above example with earth parameters g = 9.78 m/s² and cp = 1005 J/(kg*K), one calculates dT/dz = - 0.0097 K/m or the well known ~ -1K/100m. For various theoretical reasons the experimentally determined dry adiabatic lapse rate of earth is somewhat lower with 0.75K/100m, but in the same order of magnitude. Border temperature conditions are 255 K at the surface and 0K as temperature of space, from which one gets a formal thickness z of 26 km of the atmosphere.

2. As a second example, imagine the same motionless star heated from inside, nitrogen atmosphere, no background radiation from space, but by some experimental trick the lower 10 km of the atmosphere densely covered with fog and clouds. After waiting long enough, the atmosphere would again be motionless. One now has introduced very many black body radiators in the lower atmosphere. Seen from space, one would still measure the radiation of a 255K black body, but this time the radiation originates from the top of the cloudy part of the atmosphere, i.e. from an atmospheric altitude of 10 km. What is the temperature distribution of the atmosphere? To the energies of equation (1) radiation energy (Erad) must be added, either positive for absorbed energy or negative for emitted energy (Eradabs and Erademi).

Compared to example 1 nothing does change above the cloud cover, because no energy can be absorbed or emitted there. Obviously an atmospheric layer within the fog or clouds is sandwiched by and absorbs black body radiation from a warmer layer below and a cooler layer above, in stationary state emitting the average in both directions. This is why in a motionless atmosphere the radiation term averages to zero, and the lapse rate is the same within or outside the clouds. The point is however: The altitude of effective radiation to space has been shifted to an altitude of 10 km, and the lower foggy atmosphere adds another 97 K from the 255K-10km layer to ground. Ground temperature in example 2 would be 352 K, uncomfortably hot, though only heated by 240 W/m². Note that this has nothing to do with greenhouse gases, just with very simple and straight-forward physics, thermodynamics and black body radiation. Before discussing an example 3 (Venus), some additional information.

Venusian atmosphere and spectroscopic properties of CO2

As can be seen from above link, partial pressure of CO2 in the Venusian ground atmosphere amounts to ~89 bar and ground temperature to 737 K on average. The "critical point" data of CO2: p(crit.) = 72.9 bar; T(crit.) = 304 K (handbook of physics). A substance beyond the critical point is neither gas nor fluid, though in general referred to as supercritical fluid. It surely is not a gas and very surely not a trace gas. It is very important to note that the evaporation enthalpy of a substance beyond the critical becomes zero; this means there exists no cooling effect by evaporation, which is a very important energy transfer and cooling mechanism on earth. Though I have never seen the absorption or emission spectrum of a supercritical fluid, it seems safe to me to assume that such a substance behaves like a black body, not like a line or band absorber (cf. a very moist atmosphere, where water - far away from its critical point - starts behaving like a black body). Anyhow, it definitively does not make sense to extrapolate spectroscopic data of a trace gas to its supercritical conditions. And it definitively does not make sense to directly compare the physics of atmospheric band radiation (greenhouse gases) with the black body radiation of fog or clouds.

Back to Venus. According to a handbook of astronomy the top of clouds of Venus is in an altitude of about 65 km, at a pressure level of 0.2 bar. Actually the altitude of the atmosphere can be optically seen, because at the transition zone of day and night the scattered twilight looks like a sickle reaching in the night zone. Day temperature at 65 km is about 300 K, night temperature slightly below 200 K (with question mark, I cannot read the figure more precisely). Black body radiation temperature is 232 K. So there will be an above cloud greenhouse effect, but nothing overly exiting.

3. As a third example, imagine a planet-like star without rotation and with a 3-atomic atmosphere, located in space without any short or long wave back ground radiation, and heated from the inside with 163 W/m². By Stefan-Boltzmann's law, neglecting the greenhouse effect, one calculates the surface temperature of the star to be 232 K (I hope that NASA has calculated correctly; I did not check this one). Now modification by some experimental trick: the lower 65 km of the atmosphere densely covered with fog and clouds. After waiting long enough, the atmosphere would again be motionless. One now has introduced very many black body radiators in the lower atmosphere. Seen from space, one would still measure the radiation of a 232 K black body, but this time the radiation originates from the top of the cloudy part of the atmosphere, i.e. from an atmospheric altitude of 65 km. What is the temperature distribution of the atmosphere? (Sorry for this one; it is just the ease of copying).

Because no greenhouse effect (no net energy transfer) exists between atmospheric layers of very similar temperature, equation (2) can still be applied, at least in good approximation. Venus parameters for equation (2): g = 8,87 m/s²; cp = 1294 J/(kg*K) at 1 bar and 4166 J/(kg*K) at 84 bar (handbook of physics; hopefully you can see from these data alone that a supercritical fluid is not a gas). dT/dz with 1 bar data: -6.9K/km; delta T over 65 km of cloudy layer: 449 K. Surface temperature of Venus 449 + 232 = 681 K. dT/dz with 84 bar data: -2.2K/km; delta T over 65 km: 138 K. Surface temperature 370 K. Ok, this one is really too low, but it should be kept in mind that only a small fraction of the near ground atmosphere is supercritical. Also my top of the clouds altitude is presumably not very precise. Anyhow, the point of this message is that it does not make sense to attribute these ground temperatures to a greenhouse effect of trace gases. The physical reason is outlined above, quantifying the experimental observation rather satisfying.

I close this communication with a temperature emission spectrum of earth and mars, one of my favourites (ordinate radiation temperature, abscissa wave number). Note that the CO2-forcing of mars and earth (the integer of the triangle and trapezoid, respectively) are of about the same size. Here the distance of the planet to sun makes on important part of the difference. Not so with Venus. The important thing with Venus is the huge z in the dT/dz term, causing a huge delta T. By the way, could anybody provide me with an emission spectrum of Venus, comparable to the one below? I have also seen spectra from Jupiter and Saturn, but never from Venus.

kind regards       Hartwig Volz

Subject: The significance of Venusian climate
Date: Thu, 11 May 2000 21:11:16 +0100 (BST)
From: richard@courtney01.cix.co.uk (COURTNEY)
To: "Volz, Dr. Hartwig" <Hartwig.Volz@rwedea.de>

Dear Hartwig:

Thankyou very much for your analysis of equilibrium Venusian mean surface temperature. I enjoyed it and found it informative.

However, despite your superb analysis, I still do not believe that Venusian climate gives clear support for nor against strong CO2 radiative forcing on the Earth. As I previously said;

Again, thankyou.

All the best      Richard

Subject: Radiative Forcing Paper - Peter Warlow and George Birchard
Date: Fri, 12 May 2000 12:14:58 +0600
From: Peter Dietze <dommy@sltnet.lk>
To: <daly@vision.net.au>

Mr. Warlow,

I read your message during my stay in Sri Lanka and try to answer from here. You can indeed assume the CO2 effect (within the 15 µm band only) to act comparable to soot in the air. As the atmospheric emissivity (but not the available energy) increases, the upper atmosphere is cooling indeed. But the soot in the air does by no means act as if the ground becomes sooty and thus will be cooling as well (in radiative equilibrium with constant solar short wave irradiation - or cooling faster in case the Sun would be switched off). In contrary, the soot of the lower atmosphere back-radiates a part of the absorbed IR, which will result in a ground warming and increasing lapse rate as indicated in my Fig.2 - or taking your example: a slower cooling will result than if all IR emission from ground would go to space directly. In case you still doubt this and you are convinced, increasing CO2 will cause a ground cooling, you should immediately alert leading IPCC scientists about your sensational idea.

Actually, if we apply proper physics, i.e. cooling of the upper troposphere for increasing CO2, and we use IPCC's constant lapse rate, the ground should indeed be cooling instead of warming. I was very surprised when Bert Bolin wrote "Your messages have so far not provided me with new meaningful information". Possibly he had been aware of IPCC's model errors since long.

Regards, Peter Dietze

-----------

Dear George,

in your message of 27 April to Chick Keller you reasonably pointed out the cooling effect Venus' H2SO4 clouds should have, comparable to sulfate aerosols on Earth. I think, we have indeed to allocate most of the Venus heat to excessive volcanic activity in combination with an extremely dense and insulating atmosphere. Venus cannot have a greenhouse mechanism similar to Earth as solar short wave irradiation hardly reaches the ground.

Please forget most adiabatic effects in an open atmosphere - I have to tell this to many meteorologists as well. And especially to those few who even deny any natural greenhouse effect because the ground warming is asserted to be caused by air pressure. It is only a fast compression (of descending air masses) that warms the air for a short time. The static atmospheric pressure has no warming effect at all. Otherwise the warmed ground would permanently emit additional radiative energy into space and thus act as an energy producing perpetuum mobile.

Regards, Peter

Subject: Radiative Forcing Paper - Reply to Peter Dietze
Date: Sat, 20 May 2000 21:22:01 +0100
From: "P. Warlow" <warlow@globalnet.co.uk>
To: <daly@vision.net.au>

Dear John,

Would you be prepared to consider the enclosed answer for publication ? I know it's a long one again, but I don't know how to get my point across without a bit of detail in the explanation. Alternatively, perhaps, a brief note in the Open Review to say it exists and could be sent to interested individuals by request. Would that solve the problem ?

Regards, Peter Warlow

<As this was too long for the usual contributions to this file, it can be obtained from Peter Warlow at the above linked email address - JD>

Subject: [Fwd: Re: Radiative Forcing paper - final version]
Date: Tue, 23 May 2000 08:06:23 +0200
From: p_dietze@t-online.de (P. Dietze) Reply-To: 091335371@t-online.de
To: Heinz.Hug@t-online.de, Jack Barrett <100436.3604@compuserve.com>

I append a response from Tom Sheahen who had formerly measured CO2 absorption, re my radiative forcing paper www.john-daly.com/forcing/forcing.htm

I'll be at Fred Singer's Team_B TAR (anti-report-) workshop and press conferencein Washington DC 29-30 May.

Have a look at two very interesting papers by John Daly rsp Vincent Gray analyzing the 2nd IPCC TAR 2000 draft, especially the Summary for Policymakers (SPM) http://www.john-daly.com/tar-2000/tar-2000.htm http://www.john-daly.com/tar-gray/tar-spm.htm

Regards, Peter

------------------------------------------

Subject: Radiative Forcing paper - final version
Date: Mon, 22 May 2000 13:46:24 -0400
From: "Sheahen, Thomas P." <THOMAS.P.SHEAHEN@saic.com>
To: "'p_dietze@t-online.de '" <p_dietze@t-online.de>

Dear Peter:

About 20 years ago, while at the National Bureau of Standards (now NIST), I was doing an experimental study of an infrared "Thermograpy" camera, trying to see how accurate it would be under factory conditions. [T.P. Sheahen, Applied Optics 22, 1070 (1983)] Enroute to all that, I imagined that the CO2 inside the factory doubled, and the infrared device had to look through about 10 or 20 meters of such air. I used LOWTRAN, which I got from Air Force Cambridge Research Lab, to calculate the attenuation of the infrared CO2 band around 2.1 microns. To my surprise, the band saturated at rather modest distances (e.g., 10 meters). In turn this meant that changing the CO2 content of the air wasn't all that important whenever the path length exceeded 20 meters. I never followed this calculation any further, because I was only interested in a certain infrared range. Whether any other CO2 bands behave similarly is unknown to me. LOWTRAN also had another variable that could be set, called the "uniformly mixed gases", which would allow modification of CH4 in the same computational way. Probably by now these kinds of calculations are far more sophisticated. Still, I thought you'd be interested in knowing about what was being done 20 years ago with regard to CO2 doubling.

Tom Sheahen

Subject: The significance of Venusian climate
Date: Tue, 23 May 2000 14:18:21 -0600
From: Chick Keller <cfk@lanl.gov>
To: "Volz, Dr. Hartwig" <Hartwig.Volz@rwedea.de>

Richard and others,

Since I originated this discussion I'd like to head it back in the direction I originally intended, namely, I didn't ask if Venus could tell us something about CO2 greenhouse effect on Earth. I asked what would happen if the reasoning being used, (that larger amounts of CO2 than at present would not have significantly increased effects on warming) were applied to Venus which clearly has warmed a bit more than the Earth presumeably due in large part to the greenhouse effect. The reasoning used had said that more CO2 couldn't do much for several reasons. If applied to Venus, what would be its conclusions?

It was interesting to me from many (not all) of the ensuing reponses how little most people know about Venus, so this was a worthwhile exercise. I still don't think I heard an answer to my original question. Perhaps that's because Venus doesn't act enough like the Earth, i.e. sunlight doesn't make it through the thick clouds to warm the surface making the radiative transfer problem more complicated.

Charles "Chick" F. Keller,

Subject: The significance of Venusian climate
Date: Wed, 24 May 2000 10:00:20 +0200
From: "Volz, Dr. Hartwig" <Hartwig.Volz@rwedea.de>
To: 'Chick Keller'

Chick,

A remark about Venus among experts: naturally it is the convection (high winds were measured by sondes; strong turbulences in the cloud cover can be seen e.g. in UV-images) which causes the even distribution of the incoming energy from the sun. This "stirring" creates the lapse rate in the Venusian atmosphere (sum of inner and potential energy of the gas being of about the same size at all altitudes). A few days ago I read that the most dense cloud cover on Venus is between 40 and 75km (not 65km, as assumed in my example calculation). So the Venusian temperature is calculated precisely with the altitude of 75km and the corresponding CO2 lapse rate. (Looks like cheating, but is not). Just to be on the safe side (lack of knowledge on your side?), I attach an emission spectrum of earth, with and without a high cloud cover.

A with high cloud, B without cloud. I estimate this cloud forcing - without having done the precise integration - to be in the range of 200W/m². Close to no greenhouse gas (CO2) forcing above the cloud cover (spectrum A).

regards, Hartwig

Subject: Venus
Date: Wed, 24 May 2000 13:29:48 -0700
From: "Barton Levenson" <blevenson@ihfincorp.com>
To: <daly@vision.net.au>

All --

The planetary astronomy community has accepted since Sagan's 1960 paper that the greenhouse effect, due almost solely to carbon dioxide, is responsible for the high surface temperature of Venus. That's also the result I get when I use Hart's (1978) convection-corrected gray approximation for Venus. As to Venus being young -- Velikovskian catastrophism is not accepted by astronomers. There is no evidence that Venus is any younger than the rest of the planets.

Also, there is plenty of light at the surface of Venus, as the many Soviet Venera and Vega lander photographs show.

-Barton Paul Levenson

Subject: Venus again+
Date: Thu, 25 May 2000 06:27:34 -0400
From: Jack Barrett <100436.3604@compuserve.com>

Dear Friends,

Hartwig Volz has really said it all about Venus. My last message was not correct about the emissions from the planet, sorry about that. My reference to Venus being young was not meant to refer to its age, but to its maturity. I am not sure whether the venusian atmosphere was ever cooler than it is now. I think we are intended to believe that because the atmosphere of Venus looks like a runaway greenhouse effect that the same fate could happen to the Earth if we keep driving our cars and making electricity from gas and oil and coal. I do not see it like that.

Venus has a lot of carbon dioxide, but it has very little water. The water vapour content of the venusian atmosphere is about a quarter of that on Earth. It has no oceans, all water being in the gas phase. We have oceans, oceans of liquid water. HV makes the very valid point about the supercriticality of carbon dioxide, which it shows certainly at the lower levels. This means that the only means of thermal transfer are radiative transfer and molecular collisions. There is no large term from the transport of water as on Earth.

The spectroscopy is such that there is no infrared window on Venus. It is blocked by sulfur dioxide and other nasties such as aluminium chloride, iron(III) chloride and phosphorus oxides. The solar constant is around twice as large as that of Earth, but the albedo of Venus is larger so that the surfaces of both planets receive about the same intensity of solar radiation.

Whereas we are concerned about the future of our atmosphere and its thermal and spectroscopic properties, there are no Venusians to have any feelings at all. Nor will there be because the rate of escape of the nasties is not sufficient to cause any changes. Even if there were to be a cooling there is not enough water to form any kind of ocean so aqueous chemistry is forbidden. No carbonate rocks.

The BBC has had a series of programmes recently based upon current theories of global warming (except those connected with solar wind variations) and had Stephen Schneider pontificating (not about the coming ice-age) about the horrors to come. He said that there were sceptics 'who were paid to say what they say' and one wonders who is paying him for saying what he says? What is good for the goose is good for the gander as they say!

Best wishes      Jack

Subject: Additional comment
Date: Thu, 25 May 2000 12:02:08 -0400
From: Jack Barrett <100436.3604@compuserve.com>

Dear Friends,

As usual I forgot to include a comment in my previous message. It is to agree with Vincent 100% about models that do not assess their errors being 100% useless! The first thing a physicist is taught is to assess his/her errors and quote them in any physical quantity that is produced by experiment or theory. This is not done by any IPCC person and until they do a proper error assessment nobody should believe a word they say. I have constructed my own zero-order model of the atmosphere with seven parameters which are chosen by inspecting the energy budget. Allowing the chemist's rule-of-thumb 5% error in these parameters showed that the model was not worth putting any money on as a predictor of future climate.

The IPCC models have many many more than seven parameters and I think they would be ashamed of the errors that are introduced by their choices of the values used in the calculations. How about publishing an error assessment, IPCC?

Best wishes      Jack

Subject: Venus
Date: Fri, 26 May 2000 20:41:03 +0100
From: "Zbigniew Jaworowski" <jaworo@clor.waw.pl>

Dear Colleagues,

I traced the paper from which I got the information on Venus emitting forty times more energy than its get from the Sun. This is a paper by prof. Gunnar Heinsohn, Bremen University, Germany, a politologist. His source of information was probably a New York Times/Science Times issue to which I do not have access. Below is an excerpt from Heinsohn 1997 paper: "Anfang und Ende des Klimawahns", published by MZSG Management Zentrum St. Gallen, Switzerland.

Best regards, Zbigniew Jaworowski

++++++++++++++++

Venus has a smooth surface: only about 900 impact craters, when Mercury, Mars and Moon have myriad of them. This suggest that the surface of Venus has about ten times shorter age than the surface of these other bodies. The younger surface of Venus could be an effect of a giant impact, the energy of which boiled the planet (Gerald Schaber et al., US Geological Survey Flagstaff AZ). Venus irradiates forty times more energy than it receives from the Sun, as is indicated by the data from Magellan Sonde between 1990 and 1994 (Broad, W.J. 1996, "Venus's remade face offers hints of cataclysm: Earth's twin planet, with its surface radically remade by inner heat, is no twin after all" in New York Times/Science Times, 16 July, 1996).
_____________

Zbigniew Jaworowski
Central Laboratory for Radiological Protection
ul. Konwaliowa 7, 03-194 Warszawa,
Poland
voice: (48-22)717-6250;
fax: 717-5324;
e-mail: jaworo@clor.waw.pl

Subject: More on Venus
Date: Tue, 30 May 2000 06:59:03 -0700
From: "Barton Levenson" <blevenson@ihfincorp.com>
To: <daly@vision.net.au>

Zbigniew Jaworowski says:

I don't believe Venus does anything of the kind. Every analysis I've seen says Venus is in thermal equilibrium. Perhaps forty times more in the infrared is meant, since incoming solar energy is mostly in the visual. I refer the interested reader to the compilation, Venus, published by T. Gehrels and others in 1983 from the University of Arizona, especially Taylor's paper on Venus's radiative balance.

P.S. How ideologically driven is this website complex? If I were to submit a paper for open review that came to a pro-global warming conclusion, would it be posted? Please let me know.

-Barton Paul Levenson