måndag 13 december 2010

In Search of a Lost Greenhouse Effect

Judith Curry is making a heroic effort to find the physics of the atmospheric "greenhouse effect", which is much talked about but nobody has really seen:
  • We need to raise the level of our game in terms of explaining the planetary warming by infrared absorption of CO2 etc. The missing area of understanding seems to be the actual physical mechanism.
In the recent post CO2 No Feedback Sensitivity Curry questions even the very starting point of CO2 alarmism, namely a climate sensitivity of 1 C from a direct application of Stefan-Boltzmann's Law Q = sigma T^4, which in differentiated form with Q ~ 280 W/m2 and T ~ 280 K reads dQ ~ 4 dT and thus gives dT ~ 1 C upon input of "radiative forcing" of dQ ~ 4 W/m^2.

This is along the criticism I have expressed: To take 1 C as a starting point for various feedbacks is not science, because the formula Q = sigma T^4 as a model of global climate is so utterly simplistic: One can as well argue that one should take 0 C as starting point, and then enormous feedbacks would be required.

Curry admits that she does not know the physics ("the actual physical mechanism") of any atmospheric greenhouse effect, and she asks if there is anyone somewhere out there in cyberspace who does. Isn't this strange? Is the greenhouse effect dead? Was it never alive?

Compare with Slaying the Sky Dragon: Death of the Greenhouse Gas Theory (now #1 on Amazon ebook lists).

9 kommentarer:

  1. Dear prof. Johnson,

    first of all I would like to thank you for your researches and articles, showing the fallacy of the so called "greenhouse effect", on a physical (thermodynamical) and mathematical standpoint, I completely agree with you.

    I am an Italian engineer (by the way, I see from yr. cv that you have been a visiting professor here in Italy in Pavia, in 1997! I hope you have enjoyed your experience here in Italy, although - as in Sweden - propagadism of the false science of greenhouse effect, and hysteria for AGW are very widespred in media and popular culture also in Italy), and I am interested to know yr. opinion about a very interesting topic.

    As you know, Venus is considered almost everywhere the classic scientific evidence of the so called "greenhouse effect".

    (part 1)

  2. As you know, Venus is considered almost everywhere the classic scientific evidence of the so called "greenhouse effect".

    In 99% of books, articles, websites, etc., you can find almost certainly the usual phrase about the "runaway greenhouse effect", which should be proved by both the very high temperatures (737° K) and the % of CO2, wich is 96.5%.

    Unfortunately, just a few people have thought with their own brain about 2 simple facts:

    1) On Venus you find the same temperature (737°K) everywhere, both in the lighted emisphere, and on the one in total darkness. (diurnal temperatures range = 0)

    2) On Venus every day/night is 116 times longer than the one on Earth, Venus' rotation is very slow, therefore the dark emisphere does not receive ANY solar radiation at all for more than 2800 hours! (nearly 116 terrestrial days).

    And so, how can Venus atmosphere of the dark emisphere "trap" solar rays and IR radiations - as ideologists/propagandists of greenhouse effect say - if for 116 days there's NO SOLAR RADIATION AT ALL hitting the dark emisphere of Venus?

    And yet, the dark emisphere of Venus is as hot (737° K) as the one exposed for 116 days to solar radiations!

    How can it happen?

    Just by thinking about that, if someone is mentally honest, and is competent enough on physics and mathematics, it is not so difficult to find the right answer.

    The answer is that Venus temperatures are wholly caused by the 92 atmosphere of pressure on surface, solar radiations have no role at all, because the atmosphere is so dense at surface, that no solar radiation can reach Venus surface, also in the lighted side of Venus.

    (part 2)

  3. Here's the physical and mathematical proof, by using the general equation of gases.

    General equation is:

    PV = nRT
    where P is pressure in atm. which is 92 bars on Venus surface
    V is volume in liters* m^3, which is 1,000
    n is number of moles* cubic meter, and it is calculated as M (real mass) /atomic mass,
    on Venus you have a real mass of 67,000 gr CO2*cubic meter, and - as atomic mass of CO2 is 44 - you have 67,000/44 = 1522 moles * cubic meter.
    R is the universal constant of gases, which is 0.082

    Therefore, by introducing magnitudes, you have
    T = 92 * 1000/ 1522 * 0.082
    T= 92,000/124 = 737°Kelvin which is 464 ° C and it is exactly the temperature you find everywhere on the Venus surface!

    Therefore, it is not true (as Nasif Nahle writes) that Venus temperatures are caused also by solar winds, and the lack of magnetic field that does not prevent plasma heated particles from reaching Venus surface.

    The theory above cannot explain why temperatures are the same both on lighted and dark emisphere of Venus.

    No, the explaination is that Venus temperatures are caused 100% by the enormous pressures at surface, 92 atm. vs. just 1 atm. on Earth surface.

    But that means simply that 99.99% of people writing about "runaway greenhouse effect" on Venus, and pretending to be "scientists" and "experts" on this kind of topics, did not think at all about the real situation on Venus surface, and the mathemarical calculation by using the general state equation of gases.

    That's almost incredible, but it's true...people are less and less thinking about things, they just copy and repeat what other people say!

    I will be pleased to know yr. kind and important opinion on the subject.

    Thanks for yr kind attention.

    Sincerely yours


    part 3

    ps. : I tried to send you a mail to Chalmers, but mail adddress was changed

  4. You could make a herioc contribution too. Whilst the G&T paper deals mostly with strawmen you could make an attempt to analyse the real greenhouse equations from a mathematical point of view. You will probably find them in Goody and Young. Play around with them at different parameter values and see if it makes sense, and most importantly, if they have any potential of explaining lapse rates on other planets.

    Are you willing to accept the challenge?

  5. By the way. In the rather patronising blogpost of Mrs Curry she complains that the usual analogs are not effective enough to brainwash all physicists, that is, the conventional greenhouse analog and the blanket analog. It surprises me that they havn't thought of using the most striking analog of them all:

    A heatpump.

    I wonder why....

  6. Thank you Anders for yr. proposal.
    Anyway, I am not an "hero" :-))), I only made some evaluations about the commonplace according to which a planet like Venus should clearly be a place in which "greenhouse effect" is so obvious and clear.


    And so, why Venus is so hot even in the emisphere in which there is no solar radiation at all for 116 terrestrial days?
    I do believe that many people are thinking that Venus night is as short as the one on Earth, or similar, they never think about the 116 days of Venus night, and the fact that on Venus temperatures are the same both on the lighted and on the dark emisphere.

    And then if you use the general state equation of gases everything becomes very clear.
    As far as other planets are concerned, I know a very good contribution from Alan Siddons, in which he showed that the Boltzmann constant + Kirchhoff law cannot explain the temperatures of planets like Jupiter, Saturn, Uranus, Neptun, that's was really a good article.

    Anyway, I will see what I can find, and let you know...



  7. Thats great Albert, I'm sure Claes will assist you with the mathematics!

  8. Albert,
    Please do your homework before spreading confusion about Venus.

    As you can see the atmosphere of Venus rotates much faster than the planet, the upper atmosphere circles the planet in about 5 earth days. These and the other circulation patterns on Venus are quite sufficient for evening out the temperature differences over the planet, given the high density of the atmosphere.

  9. Ah, anoymous-knowing-nothing-of-physics...
    By the way, if you want to be even more precise than the Fourier equation (which is good in general for solids and resting fluids, but the concept of gradient direction from Fourier is also good for moving fluids), in calculating the heat trasmitted between two fluid layers, you can also use the Rayleigh number, i.e.
    Ra = g* Δ*ρ* L^3/μ*α

    And you will discover that a denser very hot layer – as the Venus’ atmosphere at surface – takes no influence at all from an upper colder faster rotating layer…

    But it is just a waste of time, you have no idea of thermodynamics…