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Can a blanket violate the second law of thermodynamics?

Filed under: — stefan @ 20 September 2016

One of the silliest arguments of climate deniers goes like this: the atmosphere with its greenhouse gases cannot warm the Earth’s surface, because it is colder than the surface. But heat always flows from warm to cold and never vice versa, as stated in the second law of thermodynamics.

The freshly baked Australian Senator Malcolm Roberts has recently phrased it thus in his maiden speech:

It is basic. The sun warms the earth’s surface. The surface, by contact, warms the moving, circulating atmosphere. That means the atmosphere cools the surface. How then can the atmosphere warm it? It cannot. That is why their computer models are wrong.

This is of course not only questions the increasing human-caused greenhouse effect, but in general our understanding of temperatures on all planets, which goes back to Joseph Fourier, who in 1824 was the first to understand the importance of the greenhouse effect.

The atmosphere acts like a blanket which inhibits heat loss. In fact according to Roberts’ logic, a blanket could also not have a warming effect:

It’s simple. The body warms the blanket. This means that the blanket cools the body. So how can the blanket warm it? It cannot!

The answer is simple. The warm body loses heat to the cold air. The blanket inhibits and slows this heat loss. Therefore you stay warmer under a blanket.

The Earth loses heat to the cold universe. The atmosphere inhibits this heat loss. Therefore, the surface remains warmer than it would be without the atmosphere.

It is true that the surface loses heat to the atmosphere – but less than it would otherwise lose directly to space. Just as I lose less heat to the blanket than I would otherwise lose to the air, without blanket.

Of course, in neither case is the second law of thermodynamics violated. The heat always flows from warm to cold – just more or less effectively. The processes of heat transfer are quite different – for the blanket it is mainly heat conduction, for the greenhouse effect it is thermal radiation. The climate deniers claim that the colder atmosphere cannot radiate thermal radiation towards the warmer surface. This is of course nonsense. The cool Earth also sends thermal radiation towards the hot sun – how would thermal radiation leaving Earth know how warm the surface is that it’s going to hit? It’s just that the sun sends more radiation back to us  – the net flow is from hot to cold. More is not implied by the second law of thermodynamics.

Thanks to two Germans (Gerlich and Tscheuschner of the TU Braunscheig – deeply embarrassing for this university), the absurd claim that the greenhouse effect violates the second law of thermodynamics even made it into an obscure physics journal – obviously there was no peer review to speak of. The bizarre article was promptly demolished by some US physicists. Just recently I read the claim again in an article of coal lobbyist Lars Schernikau – with such fairy-tale beliefs of its representatives, one is not surprised by the decline of the coal industry.

The thermal radiation from the atmosphere toward the ground, which allegedly cannot exist, is of course routinely measured, including its increase (see e.g. Philipona et al. 2004, 2012).

And you can even feel it. Those who sometimes sit outside in the garden after dark know this. Under a dense, low cloud layer you do not nearly get cold as fast as on a clear starry night. This is due to the thermal radiation coming from the clouds. They are colder than our body, but warmer than the night sky in clear air.

Roberts said: “Like Socrates, I love asking questions to get to the truth.”  Perhaps he will ponder my answer next time he sits in his garden at night, or slips under a blanket.


Here is the energy balance diagram for our Earth, explained in IPCC FAQ 1.1. The “Back Radiation” makes the greenhouse effect. It is larger than the solar radiation reaching the ground, and measured by a global radiation measurement network.



R. Philipona, “Radiative forcing – measured at Earth’s surface – corroborate the increasing greenhouse effect”, Geophys. Res. Lett., vol. 31, 2004.

R. Philipona, A. Kräuchi, and E. Brocard, “Solar and thermal radiation profiles and radiative forcing measured through the atmosphere”, Geophys. Res. Lett., vol. 39, pp. n/a-n/a, 2012.

229 Responses to “Can a blanket violate the second law of thermodynamics?”

  1. 201
    Thomas says:

    200 Nick Gotts – thanks for restoring my faith in humanity Nick. Proof that there are some people can read (and think properly and maturely) on this site’s comments section. :-)

    197 Keith Woollard – bollocks – go read the empirical data — better yet ask a science maths academic to explain it to you.

    194 Titus: The mods deleted my most appropriate response to you. Check back for my previous comments about you. They still fit.

    199 Mack, go back to Marohasy’s blog where you belong and tell her the arctic & antarctic ice isn’t shrinking, it’s not 37C in perth today, and the fires in NSW are merely candles on a birthday cake.

  2. 202
    Ray Ladbury says:

    What if the science indicates that action is needed?

  3. 203
    Ray Ladbury says:

    All Mack can muster is the same old “Al Gore is Fat” argument.

    Sad, really.

  4. 204
    Nick Gotts says:

    Keith Wollard@197,

    Are you serious? The history of a single glacier convinced you that the whole of climate science is completely wrong? Individual glaciers can advance while global climate is warming, or retreat while it is cooling, for local reasons. For example, warming can produce more snowfall while still not speeding melting enough to compensate, and cooling can have the opposite effect.

  5. 205
    Thomas says:

    Senator Malcolm Roberts has prepared a report about the CSIRO info provided to him re AGW/CC/co2 etc etc

    “Senator Malcolm Roberts in his maiden speech asserted that CSIRO had no empirical evidence that human emissions of CO2 caused any significant global warming.
    A meeting was arranged between CSIRO and Senator Roberts’ staff where CSIRO presented their empirical evidence.
    This document is a detailed review of that empirical evidence and has raised many questions.”

    Duly supported by Prof. Tim Ball, Tony Heller, and Australian scientist, engineer and inventor Mr Peter Bobroff (huh?)

    I think he’s Australia’s answer to Jim Inhofe and Lamar Smith.

    News report

    The Board of the Australian Environment Foundation has invited Dr Ball to give the inaugural Robert Carter Commemorative Lecture in Melbourne on the evening of Wednesday, 9 November 2016.

    [now ain’t this fun?]

  6. 206
    Mal Adapted says:


    You are not helping your cause by taking your approach. Only reinforcing already skeptical folks to increase their skepticism.

    So tell me, Titus, just what do you think my “cause” is? You’re not skeptical, you’re pseudo-skeptical, and you’re putting it on display here for all to see. You are in denial in the psychological sense, “in which a person is faced with a fact that is too uncomfortable to accept and rejects it instead, insisting that it is not true despite what may be overwhelming evidence.” We might be sympathetic to denial when it’s a response to severe personal trauma, but determined AGW-deniers like you and Mack merely wish to preserve the “freedom” to make others pay for your personal comfort and convenience. That’s bound to elicit scorn and derision in anyone who respects genuine skepticism. All I’m doing is putting my scorn and derision on display. Ain’t freedom grand?

  7. 207
    Titus says:

    Thomas @205. Thanks for the links (The news report is pay walled so didn’t get to look). Had a read of the report. Interesting to note this statement:

    “On Monday 26 September 2016 CSIRO presented, at my request, its case on climate.
    That revealed that:
    i)CSIRO has no empirical evidence proving carbon dioxide from human activity affects climate
    ii)CSIRO’s presentation contradicted the empirical climate evidence.”

    Not sure about your idea of ‘fun’ but this report seems pretty damning.

  8. 208
    Titus says:

    Thomas asking for warming/climate prediction failures.

    Okay. I took a look and to my surprise I came across oodles of examples although I’m sure many of them would not pass your test but many would. This one from one of those sites you disparage a lot gives a huge list:

    And this link is a pertinent reminder of how all this warming stuff started and what was predicted at the outset:

  9. 209
    Titus says:

    Ray Ladbury @202 says: “What if the science indicates that action is needed?”

    Then using the scientific method you retest to prove it isn’t.

    That was easy:)

  10. 210
    Thomas says:

    Roberts walks out of his own press conference – news report with short video

    In the US, where much of the climate science denial machinery has its base, the same groups who have funded organisations pushing climate science denial have started to pour money into journalism. There is now a network of outlets stridently pro-climate science denial. […]

    What happens if journalists fail to give context, fail to expose potential vested interests or fail to distinguish between genuine expertise and fringe beliefs?

    The impact is not benign. Instead of protecting the public interest, we can end up doing harm.

    Yes, politics and the media is wild and crazy as all over the West of late, and it’s getting worse very fast.

  11. 211
    Keith Woollard says:

    So I ask for an explanation on historical recede rates and I get the following responses:-
    1) Ask someone to explain it to you (hmmm, I did)
    2) Bollocks (very mature)
    3) It’s only one glacier, it must be regional.

    Do I hear you guys calling out Obama, or Greenpeace, or the National Park Service? They have all said this one glacier is a sign of CC. Should you as scientists be pointing out their error?

    Thanks for your useful responses

  12. 212

    #211–Keith Woolard, what do you want explained, exactly, and why do you think that someone here is likely to know? That is just one glacier, and for any one glacier there are going to be quite a few factors in play. One is warming; another prominent one is precipitation and the distribution thereof in time. There is a lot of sensitivity to local conditions, and hence a relatively weaker correlation to global conditions. Indeed, what we see in the recede rates teased out by the researchers is a lot of ‘noise’. (Cf., the episode of extremely rapid retreat during World War I.) To understand that, one would need to study what temperature and precipitation were doing locally.

    If you want to draw conclusions about CO2 and glaciers, I suggest it would be a whole lot more logical to ask why the great majority of glaciers world-wide are receding, and quite rapidly.

    One final note: you seem to think that warming earlier in the 20th century ‘couldn’t’ be related to anthropogenic emissions. That is not the case.

  13. 213

    Ray Ladbury @202 says: “What if the science indicates that action is needed?”

    Then using the scientific method you retest to prove it isn’t.

    That was easy:)

    Also, I am afraid, foolish.

  14. 214

    Titus, #208–

    On your two links:

    1) The WUWT ‘failed predictions’ didn’t include a single one that included a time frame (That I found, at least; I didn’t read every item on the list though I must have read at least half.) That’s not a quibble; if a ‘prediction’ is relative to, say, the year 2100, you obviously can’t judge it ‘failed’ in 2016. Many also were unclear in terms of spatial limits, which poses a similar problem. None had context, either, so we don’t know how they were intended, or even if they were intended as proper ‘predictions’ or ‘projections.’

    Bottom line: I don’t see any way that any of those supposedly ‘failed predictions’ can actually be assessed objectively, based solely on the link.

    2) The second one, far from finding that Dr. Hansen’s original prediction was wrong, found that it was at the low end of his predicted range. Ie., it was a successful prediction, albeit imperfectly so. The state of the art in 1986 was much more primitive than it is today; knowledge of forcings, computational power and modeling sophistication have all advanced tremendously. So if Mark I was already significantly successful in 1986, don’t you think we should take much more seriously today’s projections?

  15. 215
    Ray Ladbury says:

    Titus: “Then using the scientific method you retest to prove it isn’t.”

    You keep using that term “scientific method.” I don’t think it means what you think it means.

    (Please tell me you get the reference.)

  16. 216
    Titus says:

    Ray Ladbury @215

    Did a Google search of ‘scientific method’ and this was a top result:

    Quote: Step 7:
    7. Repeating the work: Arguably, the most important part of scientific inquiry! When an experiment can be repeated and the same results obtained by different experimenters, that experiment is validated.

    Also called ‘retest’, ‘falsify’, etc. What am I missing?

  17. 217
    Titus says:

    Added to 216:
    Also to note that the ‘scientific method’ does not ‘prove’ it ‘validates’ until it demonstrates a failure. That’s an important part of how science progresses.

    Big difference and a very important aspect of science that does not appear to be understood.

  18. 218
    Thomas says:

    216 Titus asks: What am I missing?

    “You can only understand what your brain allows you to understand.”
    Prof George Lakoff

  19. 219
    Chris O'Neill says:



    Number 1 on that list: ““Due to global warming, the coming winters in the local regions will become milder.”
    Stefan Rahmstorf, Potsdam Institute of Climate Impact Research, University of Potsdam, February 8, 2006”

    So how far do we have to go down that list before we get to an actual proven failure?

    What a stupid list.

  20. 220
    Chris O'Neill says:

    “Senator Malcolm Roberts in his maiden speech asserted that CSIRO had no empirical evidence that human emissions of CO2 caused any significant global warming.

    Roberts probably denies that there is any significant global warming so there is none for human emissions of CO2 to cause.

  21. 221
    zebra says:

    @ Titus #217,

    Classic case of citing something that “falsifies” your own argument.

    Either you are completely misunderstanding the meaning of words or you are trolling in a time warp back to when people said “Evolution is only a theory.”

    Theories are never falsified.
    Hypotheses are falsified.

    A Scientific Theory is not a hypothesis. A hypothesis is what you put at the top of the page of your experimental design. It is a shorthand formal way of describing the parameters of the experiment.

    Theories are never falsified.

    They may be replaced with one that provides a better framework for successful prediction, or if prediction is equal, with one that meets certain logical criteria. Until that happens, the current theory is “valid”, even if someone’s hypotheses for some experiment is falsified.

    “All glaciers will recede.” is a hypothesis.
    “The majority of glaciers will recede.” is a hypothesis.
    “Some glaciers will recede..” and so on.

    What don’t you understand about this?

  22. 222
    Ray Ladbury says:

    And the science has been repeated…again and again and again. And it keeps telling us the same thing: You cannot keep dumping powerful greenhouse gasses into the atmosphere without it changing the climate–and there are going to be some changes you really don’t like.

    And what the scientific method explicitly does not contain is a clause that allows you to keep repeating tests until you get a single result you like and then stop.

    Titus, science is my day job. I understand the scientific method–and as one who understands it, I can say pretty definitively that you do not. And no amount of cherrypicking quotes from laymen’s simplified versions of that method is going to change that.

  23. 223
    Thomas says:

    220 Chris O’Neill says:
    “Senator Malcolm Roberts probably denies that there is any significant global warming so there is none for human emissions of CO2 to cause.”

    That’s correct Chris, Roberts falls in the ‘if there’s been some warming, it’s only minor anyway.’

    Roberts is connected to the group that posits a long term ‘conspiracy’ at CSIRO/BOM in Aus and Nasa/Giss in the USA to manipulate the raw temperature data.

    As such he is a member of the Galileo movement in Aus, and has direct personal connections with Jenifer Marohasy and denier rightwing libertarian ‘unthinking tank’ the IPA, sydney institute, and others. He then has connections with Tony Heller (who co-authored this latest ‘lunacy report’) who also has been on nasa/giss for manipulating temperature data… and best cherry picking ‘sites’ that FIT THE AGW theory and dismissing all others.

    Both Roberts & Marohasy has direct connections to Bob Carter (deceased) and his #1 supporter John Nicol from JCU in qld, aus. Marohasy can no linger get a job in University, and is funded directly and indirectly by a secretive “benefactor” who owns coal mines in Indonesia [My work at CQU was wholly funded by the B. Macfie Family Foundation, and this will continue to be the source of funding for my employment at the IPA] and is friends with Gina Reinhardt (mining magnate) who is very supportive of one Christopher Monckton et al.

    example refs

    Why we should rally against homogenization,

    BIRDS OF A FEATHER FLOCK TOGETHER …. Marohasy and her hubby John Abbot (and Carters mate JOHN NICOL retired JCU professor) have been developing an alternative BUSINESS enterprise they CLAIM is a better forecaster of weather than the BOM who they are repeatedly ATTACKING SCIENTIFICALLY and POLITICALLY at the very same time.

    The next transformative technological breakthrough could come from accurate weather and climate forecasts developed from sophistical artificial neural networks.


    So while some people come up with all kinds of dubious/irrational conspiracy theories, there are some people who are IN FACT engaged in REAL CONSPIRACIES of SELF-INTEREST and FRAUDULENT activities because they have powerful friends and believe they can get away with it.

    Look up “narcissistic personality disorders” and “pathology” for more insights as to how and why people get away with lying through their teeth 24/7 as they feathered their own lifestyles of the rich and infamous.

    The world is full to the brim with Marohasys, Nicols, Abbots, Roberts, Hellers, Moncktons and worse – some also end up becoming PMs, Ministers, and Presidents.

  24. 224
  25. 225
    Titus says:

    Zebra @221 and Ray Ladbury @222

    Okay, I’ll concede a bit and use the more scientific language of ‘paradigm shift’.
    So 15 centuries of Ptolemy’s theory of an earth centered universe was falsified by Copernicus and empirical evidence supplied by Galileo. Then we have Newtons theory of gravity which was falsified by empirical evidence and Einstein came up with another theory with more in the wings. So lets put that to one side.

    Zebra brings up evolution. So let me respond to that. There is good empirical evidence that life forms change with changing environments and survival of the fittest. So there’s your theory. However, to say that life evolved from a single organism is an hypothesis with more than a dozen different hypothesis that created it. Add to that the blank slate of consciousness and what do you get? Depending on how you define evolution you get theory, hypothesis, concept and guess.

    So where does that lead me on climate change? Empirical evidence shows that CO2 is a so-called ‘greenhouse gas’ along with others, the most prominent being water vapor. So we can call that a theory. It’s effect on planetary warming is debatable, as evidence from observations and acknowledge by organizations like IPCC shows. That therefore is a hypothesis. Having this global warming hypothesis that then says it creates climate change with even less empirical evidence drops it into the reals of idea/concept.

    I majored in science at school and have a B.Sc in Chemistry. Never pursed it and 55 years has past. Times change I understand, however, that’s my two cents worth for what its worth.

    Thanks for discussion opportunity……..

  26. 226
    zebra says:

    Titus #225,

    Your age and background may explain a lot.

    Look, if you want to ignore what words mean, that’s your choice, but you are just wasting everyone’s time when you do that. It isn’t possible to have a useful discussion if you are too fixed in your ways/thinking to hear and understand what others are telling you.

    I’ll just make a couple of points.

    1. The issue of climate change is not one of Philosophy of Science– it is applied physics and engineering, using well-established disciplines like quantum mechanics, thermodynamics, fluid dynamics, and so on.

    When scientists say “hey, CO2 is going to create problems if we keep burning fossil fuels”, it is just like engineers saying “the O-rings could fail in the launch vehicle” or “you could get a bigger tsunami than you are planning for at that nuclear plant.”

    There is no “paradigm” to “shift” with respect to the science. It is just an engineering decision about what kind of energy infrastructure we (as a species) will use. Most of us who know anything about those kinds of decisions believe that the risks of BAU are substantial and the risks of reducing FF use are minimal.

    2. If you really want to stop with the climate trolling and discuss Philosophy of Science, tell me this: If Newtonian mechanics is “falsified”, how come I can calculate a trip to the moon using it?

  27. 227
    Ray Ladbury says:

    As I don’t wish to attract Creationist imbeciles to this site, I’ll forego discussion of evolution. The greenhouse effect is an observation dating from the 1820s. The mechanism was pretty well worked out by the 1850s. By the 1890s, we understood the role of greenhouse gasses well enough for Svante Arrhenius to HYPOTHESIZE that emissions of greenhouse gasses from burning fossil fuels would eventually warm the planet.

    So, the theory is that of Earth’s climate, including the role of greenhouse gasses. The hypothesis was that Earth would warm. The fact that Earth warmed provides confirmation of the hypothesis, and therefore support for the theory of Earth’s climate. There are no serious climate scientists left who dispute any of this. There are no serious climate scientists left who posit any serious rival mechanism to explain the warming–and certainly none who have a mechanism that simultaneously explains warming of the troposphere and cooling of the stratosphere. Some science is settled.

  28. 228
    Titus says:

    Zebra @225 says: “Your age and background may explain a lot”

    Do you mean the ‘wisdom that a productive full life imparts’? I’ll go along with that.

    BTW. Thanks for heads up on O rings. Never realized they behaved in a chaotic non-linear type way. Scary:)

    On your point 2. Same as saying you could use Ptolemy instead of Copernicus. They both gave pretty similar results for their time.

  29. 229
    Titus says:

    @227 Ray Ladbury. We agree on the ‘green house effect’. I don’t agree we have the knowledge or understanding of what an almost infinite number of influences have on the overall climate system.
    We just don’t have the minds, senses or tools in our current world of understanding. That’s not to say we give up. We just need to be aware and humble ourselves to admit it. Only then can we have a rational approach and work out serviceable risk. Alarm-ism, calling out fact and consensus just creates miss-trust.