Monday, October 18, 2010

The fallacy of the greenhouse effect

A recommended post from the planetary vision blog, The fallacy of the greenhouse effect, explains in simple terms why the conventional explanation of the "greenhouse effect" violates both the 1st and 2nd laws of thermodynamics:

An object can warm through the absorption of electromagnetic radiation (EMR). However, an object passively warmed can't warm the object providing the warmth. Were this to be so energy could be multiplied for no extra input merely by having objects mutually radiate EMR. But there is no such temperature multiplication because the amount mutually exchanged cancels. It does not add as is required by greenhouse theory.

The reason that an object can be heated by EMR on earth by the sun is because the sun is warmer than the earth.  The idea of the greenhouse effect is that the cooler, upper layers of air are able to warm a warmer ground by backradiation. But this can not happen.

Greenhouse theory would even require that the backradiation from the earth to the sun warms the sun by a small (if practically imperceptible) amount. This is impossible too because a cooler object can not warm a warmer one unless work is done.  But greenhouse gas, not having an energy source, can not provide this work nor can the earth provide work to the sun.

200-plus years of thermal study must be thrown out the window if we are to believe that EMR from a colder object can warm a warmer one. If that were the case energy could be made from nothing merely by bringing two objects together mutually radiating EMR (such as the air and ground) such as the following examples show.

Let object A represent a warmer object radiating to an infinite heat sink C maintained at absolute zero.  Object B is introduced into its field of radiation and so is warmed:

Object B comes up to equilibrium temperature.    Now it has its own radiation and object A is subject to more radiation than it was before (which was zero).  If the cooler object B can warm the warmer object A through backradiation then object A will heat to a higher temperature than before for free merely because object B is passively warmed.

Object A and B now radiate more energy to the universe then when A was by itself merely by B's presence. This is clearly not possible.

Now to carry it further let the sphere B be replaced by many such spheres B on one side of A.  They all radiate as much EMR as the original object B. With eight spheres the energy is multiplied eightfold according to greenhouse theory:

Object A is eight times as warmed by backradiation as it was when there was only one sphere B.  In the case of the atmosphere this is the equivalent of putting more greenhouse gas "energy absorbers" in the atmosphere.

Now let the EMR blocking coverage continue from eight spheres B to a hemispherical shell B.  This is a cross-section through B:

Now half the radiation of A is blocked by B.   According to greenhouse theory half of this half will be radiated back to object A thus warming it.  Object A now emits 100% +  25% now re-radiated back by the hemisphere B.  An extra 25% energy gain for free!

Let the hemispherical shell B become a fully enclosing spherical shell B:

According to greenhouse theory as much of the amount emitted outside of shell B will be emitted inside.  But what happens to the amount emitted inside?  Does it add to the energy?  According to greenhouse theory yes, but how can it?  Only the amount emitted to the outside of the system is relevant.

(The outside shell B must radiate a total amount which was equal to A's original output.  Being at a larger radius it will have a lower emission temperature.  Effectively the shell B is a red shifter of the EMR spectrum.  Yet the amount of energy emitted in total will be the same.)

If adding shells as greenhouse blockers could work as an energy multiplier then Willis Eschenbach's steel greenhouse model would work.  Many commenters on that thread in defence of the greenhouse effect objected to its preposterousness but it is not warranted because the model is an accurate representation of the greenhouse effect; it's just that the greenhouse effect is preposterous.

For me the resolution to the paradox is to view heat energy like a stream that only flows downhill, from warmer to cooler, despite the presence of backradiation.

An ordinary, human blanket creates warming by blocking convection not by "backradiation". An emergency aluminium foil blanket warms by a high reflectivity/low emissivity, not by absorption and re-emission.

In the case of the earth the only way that a chemical can alter temperature is by a lowered emissivity.  But greenhouse gases being good absorbers are also good emitters as per Kirchhoff's law.

An empirical example of how a cooler object can not warm a warmer object can be seen in the operation of a vacuum furnace.

go to SOURCE for rest


  1. Thanks for the post. There is some good material in it but there is also some information missing that is usually left out in these kind of thought experiments:

    Is there any HEAT ENERGY PRODUCTION in body A, for example by nuclear fusion/fission. If there is, the problem must be redefined as a heat conduction problem with source and sink, and in that case if we increase the insulation the temperature of body A will in fact increase.

    On the other hand, if there is no heat production in A the temperature will not increase, the insulation will merely slow down the cooling.

    In the case of the earth, many people are somewhat ambiguous on how they treat the incoming sunlight. Is it a heat flow that should be simply added to the outgoing radiation or is it an energy source equivalent to if it had been produced in the inside of the earth.

    In any case though, I don't think there is any substance to the claim of greenhouse gas warming.

  2. Readers should also read the treatment Dr Roy Spencer gives to this question.In his 6th of August post."Help! Back Radiation has Invaded my Backyard!"

  3. Gibo,

    Dr. Spencer's post does not prove "the greenhouse effect." Simply because a cold atmosphere at an average radiating temperature of -5C does radiate or "back-radiate," does not prove that it is capable of heating the hotter Earth at 15C in violation of the 2nd law. You will find that comments by 'Gord' and others on that post show that it proves nothing of the sort and in fact undermines the claim that greenhouse gases make the Earth hotter. As Anders notes above, insulation or GHGs merely slow cooling at night and cannot make the Earth 33C hotter in violation of the 1st and 2nd laws. Dr. Spencer admits this himself buried in the comments on his post.

  4. Thanks Anders, I noticed the limitation in my own A and B model too. For example, at first I thought maybe B doesn't warm up at all! I thought maybe the infinite heat sink was creating the paradox. And I wondered if A or B had a power source, as you say, whether that power source would be affected.

    Thanks for the plug from Hockey Schtick. I read here regularly now and it was a key site for me to understand the fallacy of the greenhouse theory. I have many links in the post back to the Hockey Schtick!

    Also, I'll be mentioning Roy Spencer in a follow-up post.

  5. I'm sorry, not to be a basher or anything, but this is completely wrong. Heat travels in three ways: convection, conduction, and radiation. The energy recieved by the earth is in the form of radiation. Then a certain amount (unaffected by the atmospheric CO2 due to the frequency of the radiation) is absorbed by the earth. This number is decreased by heavy cloudcover, which has a high "albedo" or reflectivity. Then the energy absorbed by the earth is convected and conducted around the atmosphere. But a large amount is radiated back to space (in a different frequency). The greenhouse gasses reflect the radiative energy of this wavelength back to the earth, which reabsorbs it. Then the process is repeated. Ironically, you are correct that there may be a cooling trend because, due to the higher global temperatures, more water evaporates from the oceans and other bodies of water. This evaporated water in turn creates increased cloud cover, which reflects more energy into space. The fresh-fallen snow and ice created by these clouds also increases the albedo, reflecting more energy into space. This decreases the temperature of the earth more, and as more and more ice and snow build up, the albedo (remember, that's reflectivity) increases and this cooling cycle becomes self-reinforcing and there is a global ice age. so yes, there may be a cooling trend (although i think this data is way too narrow to be able to tell for sure) but that's bad news, not good.

  6. Anonymous,
    You really don't have to try to explain the "greenhouse effect" to me - I'm very familiar with the erroneous notion you repeat - that "greenhouse gases" "trap IR heat" and "back-radiate" to supposedly make the earth hotter. As I have shown many, many times on this blog, this concept is a fallacy that violates the 1st and 2nd laws of thermodynamics. Suggest you read more posts since I can't repeat everything in this comment.

    However, the negative feedback from water vapor you discuss is probably correct and is supported by empirical evidence (e.g. Paltridge et al). The IPCC & alarmists, however, claim the water vapor feedback is highly positive.

  7. Although overall the radiation will be increased because of increased surface area, this model is incorrect.
    Because this energy is distributed via radiation, it is possible to have the radiation be reflected. That is in fact what happens. B does not "backradiate;" it instead reflects it back to the earth. Some would argue that if the energy is reflected interiorly, that it would also be reflected exteriorly. This is false, because the two radiations have two different wavelengths; this is because of an effect called "black-body radiation." The radiation from the sun (which is the form of heat we get from it) is different from that of the earth. this is the critical difference.
    Also, as a side note, your blanket model is also faulty. If that was how it worked, and the earth would get hotter, then space would serve as the ultimate blanket because it completely (for all practical purposes) insulates from conduction and convection. We would be boiling! And the 25% "free" energy cannot be true because of the conservation of energy!
    Sorry for the downer of a comment... I hope this opens your perspective a bit. but believe what you will. I really respect the time and work put into this idea, though.

  8. just saying- I never ever said anything about "trapping ER heat" and "back-radiation." The problem I have seen in this and a few other posts (I haven't seen more) is that you confuse "reflection" and "back-radiation."

    Also, I didn't mean to imply that you needed an explanation of the greenhouse effect but I figured it would be valuable for other readers.

    Just for the record, I really respect you for posting my opinion (contrary though it is) because there have been others who reject dissenting posts. Thank you

  9. No, we are not confusing reflection & "back-radiation"

    Some greenhouse proponents say that greenhouse gases are 50% reflectors of IR radiation, which I would agree with since they radiate isotropically, but even if they were perfect 100% reflectors like a mirror, they would not cause the Earth to be hotter:

    radiating cold bodies CANNOT heat hotter bodies in violation of the 2nd law and a body CANNOT heat itself by reflecting off a perfect mirror or a 50% mirror

    If you are Kiehl/Trenberth, you not only assume that greenhouse gases are perfect 100% reflectors, but that they multiply the total energy by a factor of 3 to become a 300% mirror:

  10. You are correct about reflection v. back radiation. I apologize.

    I went to your first link. I am not sure of the correctness of the "spotlight and a mirror" system; it seems like a lot to try. but the blackbody case (and maybe the whitebody case too) seem wrong. you don't take into acount other kinds of heat transfer, and atmospheric absorbtion of the radiation without re-radiation or reflection. The earth convects and conducts some of the recieved heat to the atmosphere, ect. only a certain percent will be radiated. the rest is converted to "non-radiative" (I don't know the correct term; hereafter "tangible") heat. when the reflective energy is reabsorbed, more will be lost to tangible heat, causing a rise in temperature. Another thing your models seem to fail to include is the interaction between conduction+convection, and radiation.

    First consider if the earth was in a vacuum, with no reflectors. then the earth stabilizes when:

    Energy absorbed = energy radiated

    I think (I again am not sure) that if the earth was surrounded by a vacuum with some reflectors floating (thermally isolated, one way) in space, the temperature would be where the total received radiation was equal to the total output of radiation. because some (say 50%) of the energy would be reflected back, then it would reach thermal equalibrium when:

    energy received from the sun + the 50% reflected back +25% doubly reflected + ...
    energy radiated

    I don't understand the implications of this.

    [note: .5+.25+.125 + ... = 1, so when energy is radiated in all directions, the total output does, under this set of assumptions, = the energy radiated.]

    also, I don't know if the cold/hot radiating thing is correct.
    PS I don't know what Kiehl/Trenberth is...

  11. Yes energy in=energy out, but greenhouse proponents show energy in > energy out thus supposedly warming the Earth.

    Kiehl & Trenberth are the originators of the hilarious Earth Energy Budget used by the IPCC and alarmists worldwide. For some Earth energy budgets that don't even use greenhouse gases or back-radiaiton see

  12. I think the only discrepancy is that if my case were not in a vacuum, then each time enrgy is radiated from the earth, some is (let's say x%)retained as heat (by the earth and atmospher). so for the first case, equilibrium is:

    energy recieved - energy retained = energy ratiated

    which equals:

    energy recieved - x% (energy recieved) = energy radiated

    which equals

    (100 - x)% energy recieved
    = energy radiated (which increases with the temperature of the earth)

    now, for the second case, call
    "energy recieved + 50% energy recieved + 25% energy recieved + ..." y.

    so then without transfer of heat it is:

    y= energy radiated

    note y is the total energy that hits the earth, so:

    y - x% * y = energy radiated.

    now, y is greater than "energy recieved without reflection" [because x + .5x + .25x + .125x + ... >x and x > 0 or in a generic case, x + zx + (z^2)x +... > x + wx + (w^2)x, x>0 and z>w] so then
    x% * y> x%* "energy recieved without reflection"
    and x% * y is the equilibrium temperature of the earth with reflection, and
    x% * "energy absorbed w/o reflection" is the equilibrium temperature of the earth w/o reflection,

    the equilibrium temperature of the earth w/ reflection > the equilibrium temperature of the earth w/o reflection

    or in the generic case, the world gets hotter as relfection increases, because greater reflection means greater net energy falling on the earth, despite greater net ratiated energy, causes greater absorbtion and greater temperature.

  13. also, I just went here:

    and I have an explanation for that. the energy absorbed by the atmosphere through thermals, incoming radiation, ect does equal 169, but then the outgoing radiation goes from 350 up to the atmosphere down to 165 + 30 = 195 so there is a discrepancy of 350-195 = 155. 155 + 169 = 324, thus explaining your discrepancy.

  14. This article is horribly wrong. And yes, I am a climate skeptic and I do not believe adding more CO2 will cause any significant warming.

    But yes, cooler objects DO affect how warmer objects lose their heat. As said before on the comments section, heat transfers in three ways - conduction, convection and radiation.

    The 2nd law of thermodynamics literally applies only on conduction.

    On radiation, the NET flux is always from warmer to cooler. But that simply does not mean that a cooler object can not make a hotter one cool slower.

    Here is an example pic:
    Question A: how fast is T2 cooling?
    Answer: 7F
    Question B: how fast is T2 cooling if T1 is removed?
    Answer: 8F
    This does not violate any lawas on thermodynamics or entropy since the NET flux is always on one direction.

    Photons do NOT know how warm objects will be on the route. They just radiate randomly on all directions.

    If a cooler object couldnt radiate towards warmer objects, things like IR-meters wouldnt work. I personally have an IR meter which I can measure temps between -35C and 950C, and the colder scale is measurable even if my meter itself is 20 degrees celcius.

    So in short: somehow engineers have built devices which directly measure IR radiation emitted by COLDER objects, without cooling the meter it self. If this article was right, that wouldnt be possible but someway it just is.

    Greenhouse effect is real. Positive feedbacks arent.

  15. Anonymous,
    No, this article is not wrong. The 2nd law DOES NOT only apply to conduction. The 2nd law DOES apply to radiation.

    The GHE claims the NET flux of heat is 33C from the colder atmosphere to hotter Earth to make the Earth "33C hotter than it would otherwise be."

    You are wrong about IR thermometers - they use a thermister that decreases resistance when pointed at a colder object and therefore can measure objects colder than the thermister because the thermister is LOSING heat by radiation to the colder object.

    You are wrong about 2 bodies independently spitting out photons regardless of relative temperature. Wave mechanics explains why cold bodies don't heat hotter bodies. Suggest you read several posts at Claes Johnson's site (author of several textbooks on thermodynamics). Start by reading his new chapter on "Climate Thermodynamics" linked in this post:

  16. whoa. sorry. two anonymouses going on here. I was the one posting before, but the most recent commentor (who I must say was very rude, but made some good points). just thought I'd like to clarify that. Also, did my other comment(s) get lost in the scuffle?

    Sorry for the mixup,
    Anonymous #1

  17. Anonymous,
    Not sure which comment you are referring to, but I don't necessarily take the time to refute all comments that I've already addressed ad nauseum over & over on this blog.

    If you really think that an object can make itself hotter by reflecting off a mirror, then I suggest you get a patent on your perpetual heat engine right away. And exercise extreme caution if you use 2 mirrors instead of a mirror and an object, as you could create a laser of infinite power and vaporize the planet even before AGW!!!

  18. A Fundamental Analysis of the Greenhouse Effect
    By John Nicol is worth a look..

  19. This site is just ridicilous. You dont even understand your own examples. Lets look at A first:

    Both objects are cooling, losing their heat. A black body always radiates its T^4 times bolzmanns constant. The coldy body just doesnt stop radiating just because there are hotter ones present.

    2nd law of thermodynamics says a systems entropy does not decrease unless work is done.

    The Clausius statement correctly cited:
    "No process is possible whose sole result is the transfer of heat from a body of lower temperature to a body of higher temperature."
    I couldnt emphasize the words on "SOLE RESULT!"

    Now what you are doing, you are making a huge straw man from from a half-process when 2nd law is about process and the WHOLE RESULT. 2-body systems process is radiative transfer between ALL objecs. The net flux between is what matters which is the WHOLE RESULT and which constitutes a "process", and which ultimately defines the 2nd law. Its always from hotter to colder.

    Its so basic physics anyone who doesnt understand it isnt simply credible on the whole climate issue. Not single influental skeptic scientist suspects backradiation...

    Now lets get to another example where you radiate half of the hots object back to the surface. Lets calculate it with simple vectors. Intensity of I is going away from mirror. Another similar intensity of I is also goin off. So -2I, without the mirror.

    Now you add the mirror. -I is going to mirror which reflects +I back which constitutes +-O. No energy is created it all sums up. So now the object is cooling only with a rate of I instead of 2I without the mirror. The mirror slows down the cooling rate of the object.

    As simple as that.

    None of what you have said here or none of the examples you have provided here hurt the common greenhouse theory in any way. What it does instead is ruin the credibility of many other credible climate skeptics who are focusing on the real issues...

  20. Anonymous,


    Since you are so dense on this, here's a science fair project for you: Place a body radiating at a temperature of -5C [equivalent to the average atmospheric radiating temp] close to a body radiating at a temperature of 15C [Earth] and then report back on whether the 15C body gets 60C hotter as predicted by the 'GHE'.

    Secondly, read and study Claes Johnson's chapter on climate thermodynamics:

    and then report back on all of Professor Johnson's errors. BTW if you don't find any, it is you who is ruining credibility by supporting a theory disproven by RW Wood in 1905 (and several other times since).