onsdag 19 januari 2011

The Unassailable Radiative Physics of the Greenhouse Effect

Raymond Pierrehumbert concludes his featured article in Physics Today Infrared Radiation and Planetary Temperature by:
  • The basic radiative physics of the anthropogenic greenhouse effect is unassailable.
The greenhouse effect is described as follows:
  • Adding more greenhouse gas to the atmosphere makes higher, more tenuous, formerly transparent portions of the atmosphere opaque to IR and thus increases the difference between the ground temperature and the radiating temperature.
  • The result, once the system comes into equilibrium, is surface warming.
  • The effect is particularly spectacular for Venus, whose ground temperature is 730 K. If the planet were a blackbody in equilibrium with the solar radiation received by the planet, the ground temperature would be a mere 231 K.
  • Raymond Pierrehumbert has written an excellent overview on infrared radiation and planetary temperature.
  • So, if you have followed the Climate Etc. threads, the numerous threads on this topic at Scienceofdoom, and read Pierrehumbert’s article, is anyone still unconvinced about the Tyndall gas effect and its role in maintaining planetary temperatures?
  • I’ve read Slaying the Sky Dragon and originally intended a rubuttal, but it would be too overwhelming to attempt this and probably pointless. Has anyone else read this?
What to say about this?

First, Pierrehumbert by claiming that certain radiative physics is "unassailable" (impossible to dispute) and as such makes also the greenhouse effect impossible to dispute, in fact admits that he seeks to fool people by presenting a definition as a physical fact.

A no-feedback climate sensitivity of of 1 C is also unassailable, because it is a definition disguised as a physical fact.

That Venus high temperature depends on a greenhouse effect is easy to assail: It depends on a high thermodynamic lapse rate determined by the high pressure of the thick atmosphere and is not an effect of radiation.

Second, Curry claims that she has read Slaying the Sky Dragon: Death to the Greenhouse Gas Theory, but finds it "too overwhelming" and asks for help: Is it perhaps so overwhelming even to the Sky Dragon, that it is almost unassailable? Is the slaying or assail effective and therefore not pointless?

Compare with the true story about Tyndall and His Greenhouse Effect.

PS Also Roger Pielke Sr endorses Pierrehumbert's unassailable greenhouse effect, as another skeptic confused by IPCC CO2 alarmism.

10 kommentarer:

  1. Why don't you suggest Mrs Curry and Mr Pierrehumbert to use "the Tyndall effect" of CO2 to heat their homes and save energy. In any case, it could be useful in the old english houses, they are usually very cold.

  2. Your contribution to the book is controversial. She doesn't dare to dig into this. It will take too much time to dig into properly and it's too complicated.

    But I think there is a "simple" solution to this problem. Computer simulations are popular in these days ;) Why not try to make simulations of an ideal planet with an ideal atmosphere? There are a few things that I would find interesting to modify:

    * Parameters of the atmosphere (CO2, N2, H20 etc).
    * Rotation speed of the planet (it's obvious that there will be difference with a day of 1 s and 1000 years, but is it possible to find oscillating effects or unexpected behavior?).
    * Parameters of the surface and inner of the planet (all ocean, all solid rock etc). I imagine that it will effect how far temperature differences between night and day will travel down into the core.

    As a first step it seems reasonable to omit clouds :) But in reality the clouds will of course be a major driver of the temperature since it will determine the amount of energy reaching the surface. But you have already covered this in earlier blogs.

  3. I think Nicklas makes an excellent suggestion. Rather than just debating this on the blog make a simple numerical model which demonstrate your point and make the program publically available.

    Your credentials in numerical methods are stronger than most and the results of that simple simulation is something your opponents can analyze on their own.

    Use your own favorite mathematical area to make your point!


  4. I am sorry Nicklas you clearly have no engineering background ie no understanding of thermodynamics or heat and mass transfer. There has been lots of research and measurements on these subjects over many decades. I would have thought that most intelligent persons have heard of reduced pressure, and temperature at higher altitudes. There was plenty mentioned about acclimatising for the Olympic games in Mexico city. The efforts of climbing Mount Everest is mentioned regularly in the press. Read up about the lapse rate. It is gravity that causes higher temperatures at the surface of planets with an atmosphere. This particularly applies to Venus. The pressure on the surface is about 90 atmospheres (or 9000kPa). The Russian have landed an unmanned probe on Venus while the Americans have landed on Mars. Russians have long rubbished the concept of "greenhouse" on Venus.
    I hope your year improves with a bit of reading of basic engineering texts.

  5. Cementafriend's comment about the applicable engineering knowledge should be taken to heart.

    Curry, like Pierrehumbert and all the others who keep chanting "the radiative transfer theory", is merely overwhelmed by any hint that the theory can be wrong, or misunderstood by them in any way. Pierrehumbert makes it clear by his breathless presentation of it (thank you for the link, Prof. Johnson -- I put the title before your name for those inclined to forget and dismiss, not for stuffy ritual) that it is sacred writ: The Consensus. The answer, of course, is not in the radiation, but in its effect (backradiation cannot warm the surface), and they insist upon ignoring direct absorption of solar infrared radiation by the atmosphere, even though that is the only way for the Venus atmosphere to be warmed (I know some root for a planetary internal heat, but direct absorption of incoming IR is proved by the comparison of Venus and Earth atmospheric temperatures, at corresponding pressures). We see yet again, with this article in Physics Today, just how entrenched is the incompetence. Note how the magazine (we can no longer call it a journal of science) does not acknowledge the common sense view espoused by Johnson, Gerlich and Tscheuschner, and many others who are beng ostracized in the media -- that view is so overwhelming to them, it does not exist.

  6. Cementafriend, You say "Russians have long rubbished the concept of "greenhouse" on Venus." Give a source for this claim. Without a source it is worth nothing and could be your own invention.

  7. Well try this from Chilingar et al http://www.google.com.au/#q=chilingar&hl=en&ei=exmSTOSQGdO6ccSmyPAG&start=30&sa=N&fp=4ea4a308ac696def. The following is not from a Russian but two Spanish and an Argentian http://www.nonlin-processes-geophys.net/14/641/2007/npg-14-641-2007.pdf

    Others maybe interested in the article from Abdussamatov http://www.gao.spb.ru/english/astrometr/abduss_nkj_2009.pdf given at a symposium in St Petersburg. The scientists at the Pulkovo obsveratory have been predicting for some time cooling of the atmosphere and a possible Maunder Minimum repeat.

  8. @Cementafriend, I think the link between radiation, greenhouse and athletes acclimatising to high altitudes is fairly weak, but if there is an obvious physical connection that I'm missing, please enlighten me. Also, I actually don't really see which parts of Niklas' post you are addressing.

    Given that the blog article is about reluctance to debate the underlying physics, perhaps less hand waving would be more appropriate?

    The key problem for athletes, FWIW (note, in endurance events - sprinters shattered many records in Mexico City) is that in order to transport enough oxygen to the mitochondria (the "power cells" of the body), they need to first produce more "carriers" (red blood cells), as the PO2 is lower than at sea level. This is not least because O2 diffuses from the alveoli in the lungs to the red blood vessels; lower PO2 means a lower pressure differential, and less diffusion. The body compensates by growing the red blood vessel count, thereby increasing the O2 transport capacity, but this cannot be done instantly.

    On rebutting the book, I can imagine that it would be overwhelming, but wouldn't it also be rather unscientific? Why not follow the traditional scientific principle, reduce the problem down to the most basic points of contention and start from there? It seems as if this is what Prof Johnson is trying to do.

  9. Ulf, No doubt you have good medical knowledge. It is good to see that you are reading Claes's posts and the comments. Maybe some of your English is a bit wanting. Did you miss in my comment the words "reduced pressure and temperature at higher altitudes" and the words "lapse rate"?
    The interactions affecting "climate" are very complex. No one in the world has a complete understanding. Interactions by their very nature can not be broken down into simplistic statements. I know little about the medical field but I know that humans have a brain, a heart, liver, kidneys, a spine with nerves down around it connecting the brain to various parts of the body etc. Can you simply explain the functioning of the body? If you think a little it should become apparent that the simple concept of CO2 and the incorrect use of the Stefan-Boltzman black body radiation can not explain climate changes.
    Good health
    Cementafriend (sorry about the use of a pseudonom but I have to guard relatives who are doing useful research)

  10. @Cementafriend, my English is pretty good, I think (at least that's what people tell me). I did see those words in your comment, but my failing was to see exactly which statements in Niklas's comment that upset you so much. He didn't, as far as I could tell, assume that pressure is constant throughout the atmosphere, but perhaps that was implied by "ideal atmosphere"? If so, my apologies.

    My main point of detailing the problem of acclimatisation of athletes was not to imply that *you* didn't understand that it has something to do with reduced pressure, but to illustrate that the connection is rather different from black-body radiation, and therefore not really relevant to the discussion.

    As to whether an experiment like the one Niklas suggests would be meaningful, I really have no opinion. That Prof. Johnson could enter the fray of climate modelling with his credentials seems given, but perhaps it would be better then to modify an existing model? If the altered assumptions about backradiation would improve the forecasting power (or rather the hindcasting performance, since that is testable), that would indeed be a powerful argument.