Tuesday, January 01, 2013

Greenhouse effect doesn't contradict any laws of physics

It's the new year, 2013, and I will start it with some sort of "hardcore skeptic bashing".

Needless to say, it's not the first time when you can read a text on this blog that could be described in this way. Your humble correspondent is balanced when it comes to the catching of mistakes spread by "alarmists" as well as "skeptics", "believers" as well as "infidels", and so on.

The glass greenhouses resemble the greenhouse effect in the sense that they make it harder for the heat to escape. However, the methods to achieve so are different. The greenhouse mechanically stops convection; the greenhouse effect reduces the escaping thermal radiation by absorption and re-emission of some of it downwards.

Roy Spencer wrote the following text today:
Misunderstood Basic Concepts and the Greenhouse Effect
It's of course a basic stuff but I still think it's useful to start with the comment that I agree with every word he wrote. Amusingly enough, Spencer starts with pointing out that the definition of the greenhouse effect is wrong because it suggests that the greenhouse effect depends on the sunlight and its ability to get from the Sun to the Earth's surface easily.

In reality, the greenhouse effect doesn't depend on the sunlight at all. Also, as Spencer says, it would work even if the atmosphere were absorbing the visible (solar) radiation more proactively than the infrared (thermal) radiation from the Earth.

The wrong idea that the sunlight is essential for the greenhouse effect is actually widespread – and some slightly misguided and mixed-up popular presentations of the greenhouse effect (in movies, perhaps on both sides) may be blamed for this situation. The first Google hit I get for greenhouse effect definition is the free dictionary.com and it also says that it's essential for the Earth to allow the incoming light to get through.

Let me reformulate Spencer's six basic "corrections of generally popular misconceptions" in my words:
  1. Greenhouse effect requires a warm surface but the origin of the heat may be arbitrary, e.g. geothermal, not necessarily solar. This differs from the popular delusion that the sunlight has to be there to drive the essential processes in the greenhouse effect.

  2. To determine the temperature at a given place, one must consider both incoming and outgoing energy. At thermal equilibrium, these fluxes (in the opposite directions) are equal. This contrasts with the general misconception that only the incoming energy matters.

  3. Entropy still increases, in agreement with the second law of thermodynamics, despite the preserved increased temperature difference. The usual misconception seems to assume that the thermal exchange has to lead to the equal temperatures everywhere (higher entropy) – and this thermal exchange becomes stronger when we add the infrared absorption etc. However, in reality, significant temperature differences may be created with a tiny flow of energy per second as long as the energy loss is even smaller i.e. as long as you insulate the surface well enough which is what the greenhouse effect does.

  4. Infrared absorption rate and infrared emission rate are almost always (for each layer of the air) very different from one another. This contrasts with some (mainly) skeptics' incorrect idea of a perfect balance. When you derive the rates, they're different because the emission rate grows with the fourth power of the absolute temperature while the absorption rate doesn't. What the absorption rate may depend upon is the amount of radiation around which may depend on the fourth power of the layer that emitted the heat which is mostly a hotter layer (closer to the surface) – that's really why the absorption mostly wins. Also, you can't derive the equality between the two rates from equilibrium because there are many other terms (convection etc.) that must be added to the budget when you demand that the budget is balanced. The infrared radiation-related terms don't have to cancel and usually don't cancel by themselves.

  5. Radiation going up and radiation going down from a layer aren't equal, either. This is a similar point as the previous one. The emission of radiation mostly depends on the "last molecules" on the surface and their temperature and the molecules at the top of a thin layer are slightly cooler due to the lapse rate (note that the temperature outside the flying aircraft is chilly) which means that in this discipline, the radiation going downwards slightly wins again. Despite Roy Spencer's explanation of the origin of the asymmetry, the first commenter Docmartyn seems to pretend that he hasn't seen any explanation.

  6. The existence of the lapse rate requires the greenhouse effect by itself. In the previous points, I suggested the point that the lapse rate is a necessary condition for the asymmetries that allow the greenhouse effect to operate. Once the greenhouse effect operates, it increases the insulation of the surface which means that the lapse rate becomes even larger. But the opposite causal relationship holds, too. There wouldn't be any lapse rate to start with – no cooling with the altitude – if there were no greenhouse gases (mostly water wapor) in the atmosphere. The lapse rate is close to the adiabatic one which arises because the colder air at higher altitudes is heavier (at the same pressure) so it drops down, shrinks (because the pressure is higher at lower attitudes), and heats up (squeezing a gas makes it hotter). But you see that this mechanism only works if the air at higher altitudes is actually colder then the air near the surface – and the greenhouse-effect-induced heating from the surface up is a necessary condition.
Needless to say, I do think that the physical mistakes leading some people to believe and say that the greenhouse effect is impossible as a matter of principle are mostly spread among certain groups of climate skeptics. Climate alarmists would probably not even dare to question any of the tenets – and not even learn them or verify them because even that would already be a blasphemy for most of them. ;-)

The skeptics mentioned in the previous paragraph make the right first step – to question and look for possible symmetry arguments and related arguments that could imply that the overall effect (the strength of the would-be greenhouse effect) is obliged to be zero. Some of them think that they have found such arguments but all such arguments are ultimately wrong even though one could argue that the reasons why these arguments are wrong are somewhat subtle. In some sense, you could say that the necessary asymmetries (pre-requisites) for the greenhouse effect resemble Sakharov's conditions for baryogenesis – and Sakharov had to be pretty smart to realize that they're necessary and (in principle, if you don't care about the magnitude) sufficient.

Now, every effect that can't be proved to be zero (by symmetry arguments etc.) is guaranteed to be nonzero; particle physicists call this rule "Gell-Mann's totalitarian principle" (everything that isn't forbidden is mandatory: I remember pre-1989 Czechoslovakia, too).

Still, I find it a bit frustrating that almost all the comments on Spencer's blog show the commenters' lack of understanding of the basic physical mechanisms here. Some people say that Spencer hasn't explained the origin of the downward/upward radiation asymmetry – he has. Other people claim that the greenhouse gases reduce the insulating ability of the atmosphere – the truth is the opposite. And there are lots of comments that just uncritically repeat variations of some of the "symmetry myths".

Commenter Nullius in Verba claims that the lapse rate could exist even without the greenhouse gases because of the Hadley cells. This claim is still wrong but it is really, really subtle. I think that the relevant comment here is that even the existence of the Hadley cell circulation depends on the assumption that the temperature of the air depends on the altitude – that's why the winds have altitude-dependent velocities (including direction). One needs a pre-existing lapse rate again and the greenhouse gases – heating from the surface – is necessary for that, too. Quite generally, the temperature's dependence on the latitude is thousands of times smaller than the dependence on the altitude so it would be strange to imagine that the latter is "caused" by the former. The vertical gradients are primary and they're caused directly by the (mostly) "vertical" (mostly) radiation effects – solar radiation and the greenhouse effect. The lapse rate already enters as a pre-existing condition to any sensible derivation of the Hadley cells. Another argument: you may ask how high the troposphere (with the lapse rate) is – i.e. where is its upper boundary, the tropopause. You will find out that the tropopause is determined by a balance between the downward (solar) radiation and the upward (mostly thermal) radiation and without the greenhouse effect, the tropopause would drop to the surface, a flaw that no Hadley cells could really "lift".

Finally, I find it sort of necessary to add the disclaimer that the existence of the greenhouse effect – something that has been known to physics since the 1824 arguments by Joseph Fourier – is extremely far from having any evidence that any dangerous climate change is behind the corner. What's important is how strong these effects are. We find out that the water vapor in the atmosphere is responsible for roughly 30 °C of warming near the Earth's surface while all other greenhouse gases may add 3-5 °C or so.

All these gases are contributors to the normal climate we know and love and hate, depending on the weather and our mood. If you want to study the temperature changes due to changes of the greenhouse gases, you find out that the concentration of the main contributor – water vapor – may be changing and these changes may be important for the regional climate change etc. but there's no reason to expect any trend or our contribution to this trend because the average global water vapor concentration in the air tends to quickly return to the equilibrium that is dictated mainly by the temperature. And the changes of the non-water greenhouse gases lead to pretty much negligible changes of the temperature – probably well below one Celsius degree since the beginning of the industrial revolution.

As we often say, the question whether the carbon dioxide may have a substantial effect depends on the existence of large positive feedbacks – that would amplify the "bare effect" 3 times or 5 times or more. The overall feedbacks are almost certainly not positive and large, at least not this large. I have presented tons of arguments over the years. Let me offer you a simple new one. If the greenhouse effect were amplified by a brutal multiplicative coefficient, this amplification would probably apply to the greenhouse effect caused by water, too. But the bare greenhouse effect caused by the actual water vapor in the atmosphere may be shown to be close to 30 °C and we may empirically exclude that the greenhouse effect from water adds 100 or 150 °C. So we may apparently rule out a 3-fold or 5-fold amplification of the CO2 greenhouse effect, too.


  1. I have not previously heard the simple argument of your last paragraph, Lubos. I believe that it proves conclusively that the feedback from any greenhouse gas cannot be much larger than one. Even two times is implausible.

  2. manicbeancounterJan 1, 2013, 11:46:00 PM

    Could I ask a dumb question as a non-scientist?

    The forcings that generate 30-33oC of greenhouse effect are about 324 Wm-2.

    A doubling of CO2 gives 3.7 Wm-2.

    If the relationship of forcings to temperature was linear, I would expect that doubling to increase temperatures by 0.35 to 0.4 oC. Instead I read that without feedbacks the temperature impact of a CO2 about 1.1 oC. I would expect diminishing returns from each additional unit of warming, whereas this suggests increasing returns. (I am an economics graduate)

  3. Why can't one associate knots with the Calabi-Yau manifolds and then apply Witten's recent results in Khovanov homology?

  4. The argument doesn't seem convincing to me. It might show that some conceivable feedbacks can't be very large, but not the one that is most often put forward, which is that an increase in temperature leads to more water vapour, leading to higher temperatures. The "water vapour leads to more water vapour" feedback can't be tested by looking at the present amount of water vapour. (Of course, this feedback can't be too large, or water vapour would go to infinity).

  5. Thanks, Gene, but I would not use the word "conclusively". There can be lots of surprising effects that operate under certain conditions only etc. At most, however, I would say that it's another argument that makes a strong CO2 warming hypothesis "contrived".

  6. Right, manicbeancounter, good point. The conventional coefficient lambda in

    TemperatureChange = lambda * ForcingChange

    *is* what is known as the climate sensitivity,


    so when it's small, it may be indeed linearized, and your argument would hold. However. for much lower concentrations of the water vapor, the climate would be different and would be a different sensitivity. This causes a nonlinearity - a different one than the nonlinear (logarithmic...) dependence of the forcing on the concentration.

    Nevertheless, I ultimately think that your estimate is close to the truth - it's pretty much equivalent to the argument in the last paragraphs of my text, too.

  7. http://wwwth.mpp.mpg.de/members/strings/strings2012/strings_files/program/Talks/Friday/Aganagic.pdf

  8. Item 6: "squeezing a gas makes it hotter"

    This seems at odds with the way refrigeration works Lubos, where a compressor squeezes the heat out of a gas, returning it to liquid form before it leaves the compressor and runs through the box where it returns to a gas as it picks up heat from the box and then enters the compressor where that heat is again compressed, or squeezed, out of it again.

  9. Well, eventually you run out of water to vaporize, i.e., you boil the oceans.

    I don't think even the IPCC's most extreme projection thinks this is likely, but roughly speaking it's what happened to Venus.

  10. No, woodnfish, you're confused about the way how compressors work. Gas compressor, a device that increases the gas' pressure by shrinking its volume


    always naturally increases the gas temperature, see


    The increase is somewhere in between the isothermal process (in which the temperature stays the fixed) and the adiabatic process (in which it strictly goes up).

    An easy way to see that the general temperature increase is positive is to realize that the inner energy of the gas is simply given by the kinetic energy of the molecules. One had to spend energy - do work - to compress the gas, and the only place where it could have been stored is the motion of the molecules. Because the temperature is an increasing function of the speed or kinetic energy of the molecules, it has to go up, too.

    In the fridges and other thermal engines, there are other processes that may have confused you. For example, if one keeps the pressure fixed, the volume increases with the temperature, pV=nRT. But this isn't relevant for the calculation of the lapse rate because the pressure isn't constant as a function of the altitude. Instead, the relevant condition is close to "adiabatic" (or between adiabatic and isothermal). Adiabatic means that no heat flows; isothermal means fixed temperature. In those cases, compression can never cool down the gas, and it is *especially* true and important for compressors.

  11. Jon-Anders GrannesJan 3, 2013, 11:28:00 AM

    At my house in Norway the avg yearly temperature is about 6 deg C(close to sealevel). At my cabin not so far away its 0 deg C. The difference is that my cabin is at 1100 meter height. Logically my cabin should receive more sunlight and the ground should be warmer and radiate more IR than the the surface at my house, but since its colder there than at my house other factors are at Play here? And the problem is to express this in a simple way to the public? If I took with me air from my cabin down to my house and no energy goes in or out during travel it would be approx the same temperatur as the air at my house?If not it would either sink or rise and not be there in the first place, on average?

    To make my cabin climate 6 deg warmer I would first have to make the Artic and my region climate warmer?

    Add more energy to the atmosphere Or add more air and airpressure to Earth so that the airpressure at my cabin would be 1013 hPa?

  12. Hi Jon-Anders, there may be various factors – wind, especially from the North, missing urban heat, and so on. I can't make the exact attribution without seeing the geometry around your cabin etc.

    But your example is an almost perfect textbook example of the lapse rate. The cabin is 1.1 km higher and higher altitude simply mean colder temperatures (recall the low temperature outside the airplane reported when you fly with airlines) and the difference happens to be, accidentally or not, almost exactly 6 degrees Celsius per 1.1 km, so this decrease of temperature with the height - the so-called lapse rate - almost exactly reproduces your observation. The lapse rate was discussed mainly in Spencer's point 6, but also elsewhere in this article. See a review, e.g.


    To make the complicated story short, the colder air at higher altitudes is heavier (because it is denser), therefore it drops, but as its height decreases, the pressure goes up, and increasing pressure reduces the volume and increases the tempeerature, making the previously cold air warmer. Reproducing this process (or the inverse one, the motion of warmer air up) including numbers implies that the drop of the temperature with the height should be about 6 deg C per kilometer.

  13. Jon-Anders GrannesJan 3, 2013, 11:41:00 AM

    Its also important to understand that the warmness radiates out of your fridge and not the other way around.

  14. The sun seems to warm a shallow surface layer of the oceans, plus the thermocline. Let's say 1 km deep max.
    Is the IR from (colder) greenhouse gasses of the deep ocean penetrating type? Or does warm water sink to the deep oceans? How do you explain the temperature of the deep oceans (~273K)? Maybe the geothermal flux of ~100mW/m^2 has something to do with that? Takes only ~5000 year to warm all of the oceans 1K. So the surface temperatures of the oceans can be easily explained by taking the temp. of the deep oceans plus a little sunshine. So the GHE is about 0K in total.

  15. False. you confuse temperature with energy. The higher you go, the less mass the air has, the less energy it can hold. Doesnt mean the temperature of the individual molecules is lower, there are simply less of them to warm your thermometer. To make an accurate reading on temperature, your thermometer should also lose mass as it gains altitude.

    The atmosphere's mass and opacity is what drives it's temperature, not some perpetuum mobile CO2 feedback. And it's indeed a violation of the laws of thermodynamics for an object to be warmed further by it's own heat. So the earth, transforming visible light into infrared cannot possibly be warmed any further by the same infrared.

    The greenhouse effect (IPCC version) does not exist in real life.
    Just my uneducated 2 cents.

  16. Jon-Anders GrannesJan 3, 2013, 2:11:00 PM

    Air and atmosphere is also an good insolator. The more atmosphere above you the more warm it will be above the ground with the same energy input from the Sun.
    Another another way tolook at it:
    The Winter doesnt come from the North. It comes from above? And all over the world you will find winter weather if you have high enough montains.

  17. No, Matthijs, you're wrong about all your claims, not only the non-existence of the greenhouse effect, but also about the claim that the temperature and energy shouldn't be "confused". Temperature and energy for a fixed type of molecule is always the same thing, up to a fixed coefficient independent from all other variables.

    For example, the average kinetic energy of a monoatomic gas atom is always (3/2)kT and similarly for other molecular gases where it can be (5/2)kT and so on. Temperature *is* energy per degree of freedom, and this relationship is independent of the altitude, pressure, and other things.

    At the molecular level, we have another way to calculate the lapse rate. By energy conservation, a molecule at a higher altitude falls down and gains kinetic energy, as it converts some potential energy to the kinetic form, and as the kinetic energy increases, so does the temperature. That's another reason to see why in the troposphere, the lower layers are warmer - and the gradient calculated by this molecular calculation is the same lapse rate we may determine by thinking about the compression and heating of a macroscopic body of the air.

  18. One had to spend energy - do work - to compress the gas, and the only place where it could have been stored is the motion of the molecules.

    What work does the Earth do to keep and compress gas - set and maintain the tropopause? That would be gravity.
    But gravity is a constant negative energy. You need to spend energy - do work - to overcome gravity.

    So we get to a chicken verses the egg.

    Gravity isn't changing, so the only thing a greenhouse gas can do is lower the tropopause. Conversely this action brings greeenhouse gases, or what is more commonly named nutrients, closer and more readily available to lubricate our biofunctions.

    This is why I don't swim in this shit. Introducing conundrums is the opposite of a spirit to inform in my opinion. Itjust confuses our friends and eases the way of the enemy.

  19. Jon-Anders GrannesJan 3, 2013, 7:12:00 PM

    If you bring 1 cubic with air up to my cabin it will expand and become more than a 1 cubic of air and on average 6 deg C colder than at sea level.
    If you take the same air back again it will regain its 6 deg C warmness and its 1 cubic.
    There is some sort of relativeness to it all? And you cant measure in cubic when comparing airmasses with different density(different airpressure)?

  20. Apologies, papertiger, I have no clue what you're talking about.

    For example: What does it mean "gravity is a constant negative energy"? Gravity isn't energy; gravity is an interaction, a force. Also, it is not negative: gravity adds positive or negative terms to the energy, depending on whether one moves in or out. ;-) And constant? Why constant? Gravity - gravitational force as well as gravitational energy as well as gravitational anything - is surely non-constant. So the only word in your description of gravity ("a constant negative energy") that could be preserved is the word "a".

    But equally importantly, why does it matter whether the agent doing the work is gravity? What's important is that we know that the work is done because the gas ends up having a higher pressure. It's hard to compress gas to a higher pressure so the work has been done. It doesn't matter by whom. It has been done and the invested energy only had one place to go, the kinetic energy of the gas, which is why it heated up.

    Or: "We get to a chicken verses egg". What!? ;-) First, "versus" is spelled with an "u". Second, more importantly, it doesn't matter whether you call gravity and energy chicken or egg or vice versa. I can still exactly calculate what happens in all these compression processes. It's elementary undergraduate thermodynamics. You can make it look complicated by renaming gravity as a chicken and it probably genuinely *is* complicated for you because you have clearly not mastered undergraduate thermodynamics. But it is not hard for me. It is not hard for anyone who knows basic physics. I can give you the right calculation at midnight, even if you force me to rename gravity, force, and perssure as chicken, egg, and papertiger. It's just fucking easy.

    Greenhouse gases are known as nutrients. WTF? Is that a joke? ;-) It's like confusing an elephant with a truck. What do you want to achieve by this complete linguistic chaos? A nutrient is a compound that an organism swallows to live and survive - it's a term in biology. Greenhouse gases is a gas absorbing IR radiation - a term in physics. Why do you mix up these two? Why do you mix them with mixed eggs and baked chickens or everything else? If your comment were meant seriously, could you please try to focus at least 100 more intensely than you did when you were writing your comment?

  21. Let's start with the easy part.

    Gravity is constant.

    I gained a couple pounds over the holiday. Unless you know something I don't about the Earth, it was me eating, not the Earth's gravity increasing, that caused the scale dial to spin up the few extra pounds.

    I know it offends your physics professor sensibilities to say it, but for humans and every other thing on Earth gravity is a constant. A rock, for example, as long as it's not chipped away by some activity, will weigh the same tomorrow as it does today.

    Greenhouse gases as nutrients.

    I can't see how you don't see this?

    Water, whether in vapor form or liquid, is the essential nutrient of life. Co2 is plant food. You take these things away and the plant dies. You take the by products of these things away and we die.

    I have some errands to run

  22. LOL, your explanation about eating didn't help me to follow your thought processes. Maybe I should learn some psychopathology to follow them. ;-)

    Greenhouse gases have nothing to do with eating, nutrients, or changing mass of any objects. And if one substitutes the pressure's dependence on altitude (which is of course decreasing because of gravity) as input to the calculations of the lapse rate, gravity doesn't play any additional role in the calculation whatsoever.

  23. Well, at the very least I amuse you. That's something.

    What I'm getting at is these type of posts by Spencer brush up against or are akin to the backradiation arguments. The branding iron is warmed up by the cowhide, he says.

    Load of horse manure, I say.

    You are talking about cold air getting heavier and sinking back to the Earth to be heated again. So there is gravity involved. Plus I'd say that the cold air doesn't get heavier, but rather that it runs out of the energy to fight gravity. That's why it sinks, not because it got heavier or because the earth's gravity got stronger. If you increase the insulation, less energy will escape, and the energy that formerly pushed the tropopause to x height will be something less, causing the tropopause to contract.

    Are you following my train of thought?
    Remember. I love you even if it's only to abuse me.

  24. With all due respect to Lubos explanation, what I don't think was clear is that, once the compressor compresses and heats the refrigerant, it's passed through a radiator on the outside of the refrigerator which cools the now compressed gas back to near room temps. Then as the this pressurized gas bleeds through a discharge orifice, expanding greatly, it absorbs heat to equalize the mentioned equation pV=nRT. The heat comes from the inside of the refrigerator.

  25. Lubos, there's another line of evidence that i think strengthens your argument. You've seen my examination of daily rising/falling temps here: http://www.science20.com/blog/3763

    I've found that on average worldwide temps go up and down ~18F daily. I did some mining on low wind/low humidity days and found some that the swing is as large as 60F rise/fall per day. I think this represents an average swing with water vapor vs a few rare days with very low water vapor. The 60F swing includes any effect that CO2 adds, the 18F represents the added regulation of water vapor in the mix. Daily temps are regulated by water vapor, CO2 hardly matters.

  26. Okay, confused is right, and maybe more so now, which is why I don't typically intrude on the physics discussions. But thanks for taking the time to try and cure my ignorance, Lubos.

  27. Apologies, papertiger, I don't follow your train of thought.

    In this calculation of the adiabatic lapse rate, gravity is responsible for making the pressure decay with the altitude - essentially exponentially - which may be interpreted as coming out of the Boltzmann distribution.

    But once the pressure depends on the height like that, the work needed to "lift" the air becomes irrelevant.

    One cubic meter of colder air *is* heavier than one cubic meter of hotter air at the same pressure - and the same pressure is needed for them to exist in "mechanical balance" for a while (mechanical imbalance would manifest itself before the heat exchange could smoothen the temperature).

    Why is it heavier? It boils down to pV=nRT, the state equation of the gas. If the amount of molecule "n" is fixed and the pressure is fixed, you see that the volume V is proportional to T. Colder molecules therefore occupy a smaller volume, so that there is a larger number of such colder molecules per cubic meter, and the colder gas is therefore heavier.

    This dependence of specific mass on temperature has absolutely nothing to do with gravity; it's about the inner behavior of the gas. Why don't you try to learn and understand at least this simple piece of high school physics before offering another rant about horse manures, chicken, eggs, constant and non-constant gravities, cowhides, branding irons, and other things that have nothing whatsoever to do with this physical problem?

    Thank you.

  28. When you close a cycle and return to pretty much the same state as the initial state, you may attribute the heat to the inside or outside as coming from transfer etc.

    But in individual stages of the cycle in the fridge - or any heat engine, for that matter - the heat isn't "conserved". Heat isn't a material that is just moved from one place to another - this idiotic medieval theory was called phlogiston theory.


    Temperature is the measure of (kinetic) energy carried by a single atom, more precisely single atomic degree of freedom. It may be created out of nothing. When one compresses a gas, he makes the gas hotter and the thermal energy is directly obtained from the mechanical work one has to do to compress the gas. The heat isn't stolen from any other object that would have to cool down. No one is cooling down when a vessel of gas is being compressed!

    This is really high school physics, to some extent. It's embarrassing for so many of you to be so ignorant about this basic stuff and to be so ignorant so loudly.

  29. Then you didn't either read or understand what I said. The compression of the gas increases it's temperature due to compression. Since it's now warmer than the environment, this difference is used to move this heat from the gas to the environment in the condenser. If you didn't do this, when you decompressed the gas, it would go back to a little above room temp, since you added energy during compression.

    This is how all modern air conditioners, and refrigerators work. It's also how gases are liquified.


  30. Dear Michael Crow, there's some heat flowing due to temperature differences in heat engines – and all real-world physical systems.

    But it's completely essential for the calculation of the adiabatic lapse rate that this heat flow doesn't occur at a substantial rate. It's so slow that it may be neglected, set to zero: this is what the very adjective "adiabatic" means. It means that "no heat flows". It essentially means "at fixed entropy".

    So you may be discussing some other phases of the cycles in heat engines but these phases are not relevant for the understanding of the adiabatic lapse rate and/or other topics that are on-topic in this thread. You're just confusing yourself.

  31. Since you seem a firm believer in the GHE, would you please explain the following: Earths Efffective Temperature (Te) is given as 255K. This is supposedly the base radiative temperature of a blackbody (or greybody) at the same distance from a sun as the planet under consideration.
    On top of this Te we have geothermal energy, GHE etc. that increases a planets temperature above the Te.
    Now pse explain why the moon has a Te slighly higher than that of Earth (270K iso 255K) due to lower albedo, yet it's actual average temperature is ~197K, more than 70K LOWER than its Te. Perhaps its albedo is ~0,75 iso 0.11? Or maybe this whole Te calculation is utterly wrong?
    (hint: consider the effect of averaging the inputs of non-linear functions)
    Once you discover that Earths correct Te is ~151K, let's see if an atmosphere with a heat capacity equal to that of ~3 METER of water is capable of warming the surface PLUS the deep oceans some 139K.

  32. Dear Ben,

    when you ask "correct?" for the first time, I would probably say "mostly no". Geothermal energy is completely negligible for the calculation of surface energy on Earth. Recall that 10 centimeters of wall is pretty much enough to isolate your living room from much colder/warmer temperature outside, for a long time. And we are separated not by 10 cm but kilometers of "insulation material" from the warmer places beneath the surface, so the heat flows are basically zero.

    The Moon has no greenhouse effect to speak of. Its albedo (reflectivity) is much smaller, 0.12 in average, so one expects a higher lunar temperature when "properly averaged". The proper averaging really averages not the temperature itself but the energy flows that roughly speaking scale as T^4, the fourth power of the absolute temperature.

    The lunar temperature has huge swings, due to the absence of water, atmosphere etc. It is between 40 and 400 kelvin,


    When you calculate the "average" energy thermally radiated from the Moon, it goes like T^4, so at temperatures near 400 K, it is 10,000 times greater/faster than it is at 40 K. Consequently, what happens at low temperatures - and how low the temperatures may go - is irrelevant for the energy budget. With these huge swings, what matters is pretty much the maximum temperature that is routinely achieved, and it is close to 400 K. This is the temperature you should be comparing with the average or near-record temperatures on the Earth, and be sure that the result is that the temperature-averaged-by-considering-average-thermal-radiation-as-energy-flows of the Moon is greater than that of the Earth, just like you expect.

    If the swings were small, the differences between the various kinds of averages wouldn't matter, much like they matter much less for the Earth.


  33. Takes only ~5000 year to warm all of the oceans 1K.

    Which is near the age of the world, 6,000 years, isn't it? ;-)

    In reality, the Earth has had 4.7 billion years to achieve the thermal equilibrium of the oceans, more than enough. The water is circulating in various cycles - by wind near the surface; the slowest cycles take a few thousand years - so ultimate every "molecule" of the water is exposed to the surface of the ocean where the equilibrium between the incoming solar energy and outgoing thermal energy is imposed, thus determining the water temperature.

    That's the only constraint and because the contraction of water by pressure etc. is negligible, the "adiabatic lapse rate" gives a negligible correction, too. At the end, the ocean water inevitably ends up pretty much uniformly warm. This story has nothing to do with the greenhouse effect because the solar radiation only penetrates a few meters of water and there's no significant temperature jump over there.

    Geothermal energy is negligible for the temperature of the land surface as well as the temperature of anything in the oceans.

    In reality, the ocean temperature drops more quickly in a surface layer - a kilometer or so - of "thermocline". It has various reasons, see e.g.:


    The misconception shown in your comment is *exactly* what is addressed in Spencer's points 2,3. Again, I must say that you failed to learn anything here, perhaps you didn't want to. It's a layman's misconception that the incoming energy flows have to be intense for the final temperature to be significant or significantly different than elsewhere, and so on.

    But this is just rubbish, a rudimentary misunderstanding of what actually determines the temperature. Both incoming and outgoing energy flows matter. The temperature is dictated by the equilibrium conditions. Equilibrium is when the total outgoing and incoming energy flows are equal to each other. You may think that the incoming solar energy increasing the hypothetically cooler initial temperature of the oceans is slow. But the Sun is damn strong and at any rate, the flow is fast enough so that the equilibrium is achieved in subgeological timescales and the Sun is the main "incoming" part of the budget which is why it finally determines the temperature at every place that sufficiently quickly exchanges the heat with the Earth's surface (where the need for balance is most obvious). These places include all of ocean water.

  34. You seem to forget that the sun heats the oceans from above. So any heating will almost immediately radiate/evaporate/conduct to the atmosphere and be sent off to space. At the ocean floor every Joule that escapes from inside the Earth adds to the ocean heat content.

    In eg a Snowball Earth situation this heat will buildup under the ice. Takes only ~50.000 years to warm all of the oceans ~10K.

    But more important is the fact that Earth has a temperature. The ocean floor is ~273K, and most of the ocean above has about the same temperature. Only the surface layer is considerably warmer, heated by the sun.

    So let's see about the energy budget:

    Earths ocean temperature is ~275K. The sun adds ~240W/m^2 to the surface layer, warming only the surface layer to an average ~290K. (a mere 15K warming) The oceans warm the atmosphere and in the end lose ~240W/m^2 to space. (air is a pretty good insulator) So budget balanced and temperature explained.

    For other forms of geothermal energy warming the oceans, Google "Ontong Java Plateau" and please explain how dumping 44 million km^3 of magma (may be 100 million km^3 if you include now separated other basalt floods) in the oceans will not have a warming effect.

  35. No, Ben, geothermal energy has always been negligible relatively to the solar energy propagating by circulation for the ocean temperature at any depth in all regimes of the geological history, including the Snowball Earth.

    It may be true that it takes 50,000 years for geothermal energy to modify a temperature by a few degrees, I won't check the precise numbers now. But it takes a week for solar energy (incoming) or Earth's thermal radiation (outgoing) to do the same, so these two processes simply have a much faster rate than the geothermal energy.

    When you consider the frozen ocean, it's of course a different matter. A relatively constant gradient develops at that time that interpolates between the surface temperature dictated by Earth's and solar radiation and the deep temperature - just like it works in the crust today. However, it's still true that at any reasonable depth, like 10 km of the Marianna Trench, the temperature is de facto dictated by the solar-Earth radiation balance and the thousands of Celsius degrees that are found deep inside the Earth aren't able to drag the near-surface layer of the Earth to very high temperature.

    The ocean floor is ~273K, and most of the ocean above has about the same temperature. Only the surface layer is considerably warmer, heated by the sun.

    But what you don't seem to understand is that the ocean floor has the temperature comparable to 273 K for the same reason - because the ocean circulates and the temperature from the ocean surface ultimately propagates to the ocean floor as well. There isn't any other reason than the solar-Earth radiation balance at the surface why one gets temperatures around 273 K anywhere on Earth. Your assumption that the ocean floor temperature is completely independent and determined by some totally different driver - such as geothermal energy - is completely flawed. There isn't any other driver.

  36. "The naive linear "average temperature" is calculated roughly as (40+400)/2 = 200 kelvin or so." Actually the ~197K average lunar surface temperature has been measured by satelites orbiting the moon ( Diviner project). Call NASA naive if you want, but this 197K can be explained much easier than the Te of 270K. Even the moon has a temperature. It's ~40K looking at the temp. near the pole in winter (months of zero sunshine)

  37. The reason why I called it "naive" is that it is "naive", not a good or accurate calculation of the expected energy range. This is an objective question.

    As my previous comment has demonstrated, my way of estimating the temperature range by considering the average energy flows is right while your naive method is just wrong. You may invent idiotic excuses and "references to authority" why you want to work with the naive estimate even though it's demonstrably wrong but this attitude only emphasizes your utter irrationality and inability to think about the world as a physicist.

  38. See eg


    Just below the oceans crust the temperature is already hundreds of degrees. Although small, even a heat flux is established.
    In my world warm(er) water floats to the surface, it doesn't sink to the bottom.
    Looking at
    any where on the world at and below ~2000m the temperature is roughly equal to the bottom temperature.
    How would your greenhouse gasses warm the deep oceans?
    (I am aware of the thermohaline circulation)

  39. So you are saying that dumping 100 million km^3 magma with a temperature of at least 1200K into 1300 million km^3 ocean will not change its temperature?

  40. No, as everyone who knows how to read has noticed, I have never talked about dumping cubic kilometers of magma to the ocean.

    I was talking about the oceans separated from the magma by kilometers of rock, and indeed, it's a totally different situation than dumping magma to the ocean. The exchange of heat with hot magma separated by a kilometers-thick layer of rock is completely negligible.

  41. Dear Ben,

    you're very confused about the picture. The temperatures 600 deg C on the picture are in the middle of the lithosphere and the lithosphere is 50-100 km thick. So it's surely not "just below" the ocean crust. It's tens of kilometers lower.

    The temperature gradient in the rock never exceeds a dozen of degrees per kilometer or so and this is such an incredibly slow temperature change that the resulting heat flux induced by the gradient is pretty much zero, surely negligible - at least by a factor of a million smaller relatively to the convection.

    Be sure that the greenhouse gases do impact the temperature on the ocean floor, too. If there were no greenhouse effect in the atmosphere, the ocean floor would be 30 deg C cooler in average, too. Well, it would freeze rather soon.


  42. I don't claim that geothermal energy does anything on a day to day basis. In special cases like extended ice cover of the ocean surface, it takes only ~50.00 years to warm the ocean under the ice some 10K. Should be enough to melt that ice.
    I assume you didn't read this article:
    This is about 100 million km^3 hot magma bursting through the crust and forming a basalt flood ON the crust after cooling down. The deep ocean temperatures after this major seismic event and following smaller ones reached about 15-17K above present temperatures. We have been cooling down since a peak some 80-85 million years ago.

  43. Thanks for the compliment, but you still haven't answered the question why moons actual temperature is so much LOWER than the Te, which is calculated in the same way as the welknown 255K Te for our Earth.

    See http://bartonpaullevenson.com/Albedos.html
    for a discussion of Te.

  44. Go to a Scuba Diving Store that fills tanks. See how hot the tank valve gets during filling. Next, take a full SCUBA tank and open the valve and see how frost forms.

  45. I give as much as I get while shoveling the manure. Maybe more.

    So I don't mind getting cuffed a bit for belligerent rants, but saying that the branding iron doesn't get heated up by
    the cowhide - that is my formulation of the 2nd law of thermodynamics - it's not a rant. It's a truism.

    I availed myself of your kind suggestion and discovered this guy. Rudolf Clausius.

    Rudolf said, "Heat can never pass from a colder to a warmer body without some other change, connected therewith,
    occurring at the same time."

    Which can be stated another way as,

    "No process is possible whose sole result is the transfer of heat from a body of lower temperature to a body of higher temperature."

    Heat cannot spontaneously flow from cold regions to hot regions without external work being performed on the system.

    Which means that there is no way that the cowhide will heat up the branding iron, or there is no way that the layers of air no matter their composition, or how convoluted they become, will heat up the Earth or any volume of air closer to the Earth. The Earth is the air's supply of heat. The air is the Earth's heat sink.

    Lord Kelvin said it like this, "It is impossible, by means of inanimate material agency, to derive mechanical effect
    from any portion of matter by cooling it below the temperature of the coldest of the surrounding objects."

    Or said another way, "No process is possible in which the sole result is the absorption of heat from a reservoir and
    its complete conversion into work."

    Don't you love the way they talk? No ambiguity.

    What is the work in this case? It's the lifting of air away from the
    surface of the Earth. Everything between the sea level and the tropopause is lifted to it's height by Earth emissions.
    The tropopause is the point in space where the emission can no longer overcome the Earth's gravitation.
    If someone were to calculate the weight of everything floating in the troposphere and the amount of energy it takes to lift it, adding that bit on the emission side of the ledger would go along way toward reconciling the discrepency
    between absorption and emission.

    Once that is done there will be no need for a greenhouse effect to describe reality. Co2 will be returned to it's rightful position, it's concentration determined as a result of temperature changes, rather than as a cause.

  46. Dear papertiger, your approach to thermodynamics is just utterly irrational.

    You quote some founders of thermodynamics, probably to fool yourself into thinking that you're in harmony with them, and then you continue with totally preposterously wrong statements such as "Earth is air's heat sink and heat source". The Earth (geothermal energy) is completely irrelevant for the determination of the temperature near the surface, of the air, or anywhere in the ocean as it contributes less than 0.05% to the energy budgets.

    None of the processes that you declared impossible is impossible, none of them contradicts the second law of thermodynamics. The layer of greenhouse gases is just a damn blanket on your bed. It slows down the escape of energy, thus raising the equilibrium temperature just like in the bed. Or in the glass greenhouse, for that matter. What's so difficult about the basic fact that this effect surely does occur?

  47. Lubos has answered your question, but you obviously didn't understand his answer. You should inform yourself about the basic physical principles before continuing this discussion.

  48. Lubos, Ive been waiting a year for you to answer my question as to why you believe outer space is "cold." Once you disabuse yourself of that notion you can then understand that vacuum space is nature's perfect insulator obviating the bogus 'blanket effect' analogy. There are 200+ scientists at PSI itching to challenge you to a public debate. You claim the GHE is "basic stuff." If you know all this "basic stuff' you should then easily defeat my colleagues in any such debate. Thanks.

  49. Dear John, I am not aware that the (trivial) question "why the space is cold" has ever been asked to me. If I had seen the question, I would have immediately answered it, just like I do it here.

    First, operationally. You may measure the temperature of outer space by a thermometer, e.g. one based on mercury. Shoot a mercury thermometer to outer space and wait once the mercury stops moving i.e. thermal equilibrium is reached. Clearly, it will only be reached once the mercury will stop radiating. The thermometer will have cooled down to 2.7 kelvins, i.e. -270 Celsius degrees or so, the temperature of the microwave background.

    Theoretically. Empty space, vacuum, is the state of the Universe with the lowest possible energy. It means that the probability is zero that the energy is higher than the minimum one by E. However, the thermal ensemble is defined by having the probability of energy "E" suppressed by exp(-E/kT). Because exp(-E/kT) already has to be zero for a finite E, it follows that kT itself has to be zero (an infinitesimal positive number), too. Its inverse is +infty and exp(-infty) is zero.

    Also, it's wrong in the physics of radiation to say that the vacuum is a perfect insulator. The heat may propagate through it - in the form of radiation because the vacuum is transparent with respect to radiation. If it can propagate through it, it is a heat conductor. The addition of the greenhouse gases makes the region less transparent to the thermal radiation so the heat that arrives in the form of radiation may be absorbed and stored for a while before it's re-radiated, typically at a higher temperature than what we would have with the vacuum where the "delay" or "storage" is absent.

    I just want to make you sure that this is really basic, basic 19th century physics that someone who wants to be a physicist should understand already at the high school. It is very stupid and arrogant for you to be both ignorant about this basic physics and to be proud about it.

  50. I imagine that's John O'Sullivan the journalist. Especially in science, very especially with global warming, journalists can mislead by knowing some things and not others, especially when the latter are basics. Anyone can be misled, if, by chance, he has only read those parts of the journalist's writings which happen to be more or less correct. When he runs into an incorrect part, he's shocked.

    I know that may sound trivial, but I've been shocked this way more than once, and it's quite an experience - funny, among other things.

  51. Yet on the night side of Venus it can get as WARM (sorry I obviously mean cold...) as MINUS 90C.
    Maybe that is due to the fact the day is longer than the year on Venus. Sounds far more probable to me than some imaginary "greenhouse effect".

  52. First of all I didn't say the Earth was a heat sink, it's the other way around of course. And I didn't say anything about geologic activities. (Maybe you were thinking of the other guy?). My statements are in regard to the solar power absorbed and reemitted as IR only. I consider the vulcanic heat output inconsequential as well (If the sun stopped shining (the Earth only ran on geothermal) then we really would have the tropopause dropping to the deck).

    Neither Kelvin nor I said anything about "impossible". We just said it would be a lot of work. More like dunking a cat into the toilet to warm up the water, than like a nice cuddly blanket.

    But if you don't like Kelvin I got other people I know.

    Here's a quote for you,

    The entropy is increasing in every cubed inch of matter. It is increasing every second. It is not increasing just if you average the observations over cosmological distances. The thermodynamic phenomena are universal and their key underlying processes are associated with physics at the atomic, microscopic, and possibly mesoscopic scales, not the astronomical or cosmological ones!

    And here's another,

    For example, if you boil a soup, it will be "almost certainly" getting cooler once you turn the stove off. This is obviously true even in a very big multiverse with many bubbles and pockets. The correctly calculated probability that the soup will spontaneously warm up by cooling down the (already cool) table and extracting extra energy out of it will be exponentially small in any universe or multiverse.
    You would need a wrong calculation - e.g. one that "cherry-picks" anomalous events and abuses them in a flawed "statistical" calculation - to obtain a different result. The very same comment applies to any lab predictions you can think of. Get used to it. There's no logically valid derivation of anomalous phenomena - such as Boltzmann's Brains - in any cosmological setup as long as the approximate locality, Standard-Model-like local laws of physics, and basic rules of logic are preserved.

    That's from this guy I know, one of the best posts he's ever written called The Arrow of Time Understood for 100 years.

    Speaking of impossible, since you brought it up, how is it possible that the co2 greenhouse effect warming arrives 400, 800, or 1000 years before the co2 blanket (depending on which interpretation of the ice cores you use)?

    And if the co2 and methane gases control the temperature (no matter in how slight a fashion) rather than the temperature deciding the concentrations, why do the co2 and methane levels rise in unison after the temperature lag?




    Your's and Spencer's speculative interpretation is in violation of the arrow of time.

  53. Dear papertiger, this is tiresome. You clearly seem to think that you know something about physics of the Earth - and any relevant physics - but you just obviously don't.

    The Earth is neither a significant source nor a significant sink, as far as geothermal energy's contribution in the energy budgets of the surface, oceans, or the atmosphere goes.

    If the Sun stopped, the surface of the Earth after billions of years would obviously be (even) colder than it is today. Its temperature would be close to the temperature of the outer space, -270 Celsius degrees. What does it mean for you to say that the Earth would switch to geothermal energy? It makes no sense.

    The thousands of degrees that would still exist deep inside the Earth would still make no impact on the surface temperature of the Earth simply because the exchange of heat between the surface and the outer space in the form of radiation is far more effective than the conduction of heat through kilometers of insulating rock. Geothermal energy would always be negligible for a solid celestial body of a planetary size.

    All the quotes you offered are right but none of them supports your indefensible positions about the energy flows. In particular, entropy is always dominated by atoms, microscopic building blocks' entropy. That's true for any part of the Earth, too. The entropy change associated with the heat transfer is mostly carried by the photons of the radiation and atoms. This has nothing whatsoever with cosmology. The degrees of freedom governing the shape or size of the Universe are completely irrelevant for the Earth's budget. But the heat coming from the Sun isn't negligible. But the heat coming from the Sun isn't about cosmological parameters; the radiation is a flow of quintillions of photons, lots of massless "matter", lots of elementary particles.

    As explained by Spencer and me, your "new" proposition that the greenhouse effect or any component of it violates the second law of thermodynamics - heat never spontaneously flows from a colder object to a warmer one - is also wrong. It has been explained many times. Why are you offering this crackpottery again? Sorry but if you continue in this way, I will have to start to delete your comments because they are crackpottery spam and above a certain level of repetitiveness, it's simply my policy not to allow this junk-status material to be repeatedly posted on this blog.

  54. Why are you still pounding on the geothermal? I didn't address the topic except to point out that I didn't bring the topic up.

    You must be confusing me with Ben is the only thing I can figure.

  55. Always possible that I read it wrong, as drunk as I am most of the time. Let's revisit my understanding of the thing, then at least you'll know what I'm bitching about. Forget the geothermal stuff. This is the part that bothers me. Item number 5.

    5) "Each layer of the atmosphere does not emit as much IR upward as it does downward."

    Cutting out the flowery stuff, the operative bit being "Ground-based, upward-viewing IR radiometers measure much stronger levels of downward atmospheric emission than do space-based, downward-viewing radiometers of upward atmospheric emission."

    Lab experiment. Let's use a caldera made from a substance which is a perfect emitter of heat. I don't know what substance that would be, but let us imagine there is a caldera which is perfectly transparent to heat. Lets give it ten foot legs, so it resembles the Olympic flame rising over a stadium. Now lets throw some charcoal on the barbie.Stoke that fire up real hot. Now lets set up a platform (better make it fireproof) ten feet above the caldera. Then we throw in some test subjects. Since there will be no volunteers, I'll stand on the platform. You stand underneath the caldera. Who do you think is going to get burned?

    Every fibre of my being tells me that I will be burned, while Professor Motl, standing safely underneath, will be unscathed.

    There's not a question of just a little temperature difference between the two - there is a huge gaping chasm between the two.

    Every experience in my life tells me Spencer is wrong about number five. Every luminary from the pantheon of thermodynamics tells me Spencer is wrong about number five. The lab says Spencer is wrong about number five. What am I missing that makes you think he is right?

    Could it be the matter of perspective leading Spencer to missinterpreted measurements? Could it be that ground based IR radiometers, being nested in the bosom of the Earth's warmth do not share a one to one relationship with satellite based radiometers? Is it a question of comparing apples and oranges?

    At least you can scold me for the right reason this time.

  56. Dear papertiger, I am pounding on "geothermal" because you (and I checked it's you and not [just] Ben) wrote that the Earth is the opposite of a heat sink - i.e. a heat source. Now, translate "Earth's heat" into classic languages and you will get "geo-thermal". Earth is geo and heat is thermal.

    In reality, the bulk of the Earth - the rock deep beneath the surface - has a virtually negligible effect on the temperature near the surface, atmosphere, or oceans.

    " Let's use a caldera made from a substance which is a perfect emitter of heat. I don't know what substance that would be, but let us imagine there is a caldera which is perfectly transparent to heat."

    Papertiger, this is physically impossible. A perfect emitter of heat is a "black body" but a black body must simultaneously be a perfect absorber of radiation, i.e. perfectly *opaque* to heat. The equality between emissivity and absorptivity is known as Kirchhoff's law.


    I won't discuss your thought experiment because it's a "what if" kind of experiment about something that is forbidden by the most universal laws of physics. Once you allow things that are forbidden by the laws of physics, everything goes.

  57. Lubos, as you are not a space scientist and engineer who helped design the Apollo spacecraft I tend to dismiss your "stupid and ignorant" pseudo science concerning "cold" space and nature's perfect vacuum. I prefer to rely on those space scientists at Principia Scientific International who have highly successful careers in such endeavors. That you actually believe your thermometer in space is measuring anything other than itself is laughable. The thermometer is only measuring itself because it is in a vacuum. I suggest you try to read up on what NASA has to say on this:


    NASA admits, in the above link ‘Staying Cool in Space’ that the "ISS needs huge radiators to get rid of its excess heat." So much for the ‘cold’ of space! So deadly is the risk of astronauts being cooked alive in the ‘cold’ tin can of the ISS that the vehicle requires 14 honeycombed aluminum panels each measuring 6 by 10 feet (1.8 by 3 meters), for a total of 1680 square feet (156 square meters) of ammonia-tubing-filled heat exchange area just to stay cool.

    Even Wikipedia understands this: "Deep space is generally much more empty than any artificial vacuum."


    This is why we use thermos flasks: to inhibit the exchange of heat energy between the liquid inside and the environment outside. IF the vacuum of space were cold - then it would be true what Spencer (and many GHE supporters) maintain, namely: the colder body reduces the rate of the heat loss by the hotter body, etc.

    But because we know that vacuum space is neither cold nor hot (being almost void of matter and thus having no temperature) we can clearly see the aftermath of Spencer's wrong idea of a 'cold' vacuum of outer space. This basic astrophysics fact you should admit. Once you do then you then will see that there is no GHE ‘Heat Loss Blanket Effect’ because Vacuum Space is ‘Neutral’ not ‘Cold.’

  58. Dear John,

    with all my respect to you, I won't discuss your references to Apollo rocket scientists who allegedly support your crackpot physics because the idiocy of such a proclamation is self-evident.

    It doesn't matter that there's a vacuum around. The heat is still inevitably propagating via radiation, so even with the vacuum in between, objects ultimately reach thermal equilibrium. It's just a matter of how quickly. And be sure that when it comes to energy flows in the atmosphere, the exchange of heat by radiation is the most efficient one. Radiation is responsible for the largest contributions in energy budgets and temperature changes of anything in the atmosphere.

    Please try to learn some basics of physics such as black-body radiation


    and reduce your frequency of posting utter rubbish on my website - and, if possible, other websites - at least by a few order of magnitude because you're one of the guys who reinforce the flawed opinion by many otherwise reasonable people that climate skeptics are universally cranks.


  59. Yeah that "geothermal". Just as a word, it's almost designed to cause confusion. Shame people still resort to it.

    A cauldron's not forbidden here. It's just prohibitively pricey.
    Steel Campfire Cauldron Tripod fire pit.

    Strange about the different laws people have to live with. Like here for instance, you can't have a spittoon open to the public in your place of business.

    A constructive suggestion you made for modifying the experiment. Lets forget about impossible and work with what we got.

    Instead of a cook pot full of burning charcoal, let's fill it with molten iron at 1500°C . That way it glows the same in all directions.

    I'll still take the Pepsi challenge with you on that. All day and every day.

  60. This exchange between Boss and Tyger had been leading inexorably to a re-enactment of a certain well-known PF scene but now... anticlimax! I feel cheated.

  61. I'm a hard core skeptic, and for the record Marcella Wallace looks like a quadruple bypass slipping on a cheeze burger waiting to happen.

  62. "Do not give what is holy to the dogs; nor cast your pearls before swine,
    lest they trample them under their feet, and turn and tear you in
    pieces." Matthew 7:6
    (not bad for an atheist :) )
    It seems like the topic "Greenhouse effect" is a crackpot magnet. Maybe we can quarantine them like virus scanners do when they can't delete them. Denying the Greenhouse effect just provides ammo for RealClimate and its toxic cohort.

  63. John O'Sullivan

    NASA admits, in the above link ‘Staying Cool in Space’ that the "ISS needs huge radiators to get rid of its excess heat." So much for the
    ‘cold’ of space!

    If space, as you say, is "Nature's perfect insulator," how can the radiators work, and how does the sun heat the earth?

  64. Let's give Mr. O'Sullivan a tank with a breathable mixture of gases, attached via a hose to a tight-fitting facemask. We will now put him in an airlock aboard the ISS and push him out to space. He has plenty of air so there is no danger of suffocation. We made sure he would not be harmed by a sudden drop in atmospheric pressure. An hour later, we reel him back in and pay him a million dollars if he is still alive. I forgot to say that he is still wearing civilian clothes only, no spacesuit. However, that shouldn't be a problem because Vacuum Space is Neutral :)

  65. Another thing... O'Sullivan writes, "This is why we use thermos flasks: to inhibit the exchange of heat energy between the liquid inside and the environment outside". Well, yes. A thermos flask does work that way. However, he forgets that it isn't the near-vacuum in the flask wall alone that does this, you need to line it with a reflective layer, too! See

  66. I don't know Boss. You said it yourself that "the thermodynamic phenomena are universal and their key underlying processes are associated with physics at the atomic, microscopic, and possibly mesoscopic scales,".

    My experiment is closer in scale to Spencer's radiometer, then Spencer's radiometer is close to individual molecules.

  67. It is frightening to think that someone who does not understand how the sun heats the earth can have an opinion on climate change (and can vote). Here is some basic education for you at a very elementary level, with pictures, on heat transfer, conduction, convection and radiation: http://www.wisc-online.com/Objects/ViewObject.aspx?ID=sce304.

  68. Lubos,

    You say "There wouldn't be any lapse rate to start with – no cooling with the altitude – if there were no greenhouse gases (mostly water wapor) in the atmosphere."

    When did you start ignoring potential energy?

    Please see http://climateofsophistry.com/2013/01/02/the-fraud-of-the-aghe-part-9-the-truth-about-the-cooling-atmosphere-and-the-lapse-rate/ where Joseph Postma gives a succinct explanation of the lapse rate, plus a good, and in my opinion correct, explanation of water's influence on lapse rate via transfer of latent heat.



  69. Dear David, the greenhouse effect on Venus is far stronger than the greenhouse effect on the Earth and CO2, not water, is the dominant greenhouse gas there. Not shocking it's important because the partial density of CO2 is about 100,000 times greater on Venus than it is on Earth.

    So the greenhouse effect is far more important for the lapse rate on Venus and adds much more temperature increment to the climate of Venus than it does on Earth.

    Therefore, everything I said about the Earth is even more true about Venus. The greenhouse gases also play a crucial role in the planet's having any circulation and lapse rate. Venus also has many other differences like dark clouds that make the atmosphere largely opaque to sunlight etc. but these are independent issues.

    Many wrong things have been said about Venus in the past, arguably including myself, but be sure what what I wrote here is right.

  70. Dear Lubos,

    Thank you for your reply, but I am disappointed.

    If you no longer believe that the pressure profile created by gravity also creates the lapse rate, could you at least, please explain exactly what a greenhouse gas is, what it does, and how it causes circulation or lapse rate; in a quantitative way that is consistent with conditions found on both Earth and Venus?

    Thank you,


  71. Dear David, why don't you search in the basic literature to answer these elementary questions?

    A greenhouse gas is a gas that absorbs - and emits - infrared radiation which is the thermal radiation corresponding to the temperature of the Earth. It's important because the radiation emitted by the Earth and by the atmosphere is partially absorbed and the rate by which the heat may radiatively escape from the Earth is therefore reduced, like in a blanket.

    Consequently, the atmosphere is being heated from below which means that warmer - and therefore less dense, lighter - air is at lower altitudes and wants to go up, and vice versa, which is why this layer of the atmosphere heated from below - the troposphere - is circulating, has the lapse rate, and has all the interesting and complex circulation patterns and weather.

    The lapse rate in the troposphere is therefore caused by the greenhouse gases and the more greenhouse gases one adds, the thicker the troposphere may become, and - given a nearly constant temperature of the tropopause, the top of the troposphere - the warmer the surface ends up.

    Greenhouse effect, mostly due to H2O, adds 30-35 Celsius degrees to the surface of Earth and hundreds of degrees of Venus (where it's due to CO2, almost entirely).

    I am confident that I have explained those things in quite some detail and you just want to waste my time and create the feeling of doubts where there are no doubts.

  72. Lubos,

    If Pv does not equal nRT, then perhaps you are correct, but otherwise, I have serious doubts that you could ever derive values for "radiative forcings" that would give consistent results for atmospheres of both Earth and Venus.

    Just my two cents.

  73. The reasonable temperature to assign to a point in space is the temperature equivalent to energy density at that point which can be calculated by summing the energy impinging on it .

    That is the temperature to which a flat spectrum gray ball will come to . In our obit that is about 279 kelvin , about 4 centigrade .

    Note that when Apollo 13 lost its power it didn't plunge towards absolute zero , it fell to somewhere around that 4 or 5c value .

  74. Dear David, no, none of the mechanisms above - such as the greenhouse effect - depend on deviations from the ideal gas.

  75. Dear Bob, again, the surface of Venus is some hundreds of degrees warmer than it would be because of CO2 because of the greenhouse effect.

    The greenhouse effect isn't caused by "reflection". It is caused by emission and especially absorption of IR radiation which is something entirely different.

    Quite generally, venuso-thermal (not "geothermal") energy doesn't play any significant role because the surface is isolated from the interior by thousands of kilometers of rock. The bodies where the internal energy - thermonuclear energy - plays a role are called stars. They're burning. But nothing in planets is burning and if it is, it wouldn't manage to burn for billions of years, and so on, and so on.

  76. Dear Lubos , That's a specific example of what I said . By my calculation at http://climatewiki.org/wiki/Category:Essential_Physics#Calculating_the_Temperature_of_a_radiantly_heated_Gray_Ball , , the energy contributed by the 3k of 0.9999946 of the celestial sphere not covered by sun is utterly insignificant .

    What I take issue with is the confusion which comes from the notion that vacuum is intrinsically cold rather than determined by the radiant energy density at a given place .

    Your critique of the Heartland wiki page would be most useful .

  77. As I said , the surface of Venus is about 2.25 times the temperature of a point ( gray ball ) in its orbit . That is , the energy density at its surface is about 25.6 time that of a point next to it in its orbit . That is NOT explainable by CO2 "trapping" energy from the sun altho that is surely very much a factor in holding in internally created , venuso-thermal if you like , heat . Io is a good example of a planetary body , to be picky moon , with enormous internal heating , in that case , likely tidal .

    For an opaque object , and planets appear opaque from the outside except for their thin atmospheric limbs , radiation is either absorbed or reflected . I could have stated the the "radiant balance" condition in terms of absorption=emission ( they are the same coin ) rather than reflection , but Venus's reflectivity , albedo , is what is striking about it .

    The bottom line is that given Venus's reported albedo with respect to the sun of about 0.9 , absorptivity 0.1 , in order to create a ratio of 25.6 in energy density , its absorptivity=emissivity in the long wavelengths must be about 0.004 . It's the view from outside which determines the equilibrium , not from the surface . If the surface temperature of Venus is to be explained totally in terms of energy from the Sun , it's "albedo" in the IR must be around 0.996 . Otherwise Stefan-Boltzmann and Kirchhoff are wrong .

    I would very much appreciate your comments on my http://cosy.com/y12/NewsLetter201212.html#PlanetaryModel and Calculating the Temperature of a Radiantly Heated Colored Ball on which it builds .

  78. I certainly fail to understand . We come to the same values for the energy density at a given distance from the sun don't we ? We agree that that is the mean temperature a flat spectrum ball in that orbit will come to don't we ?

    We agree on the ratio between Venus's surface temperature and that of a flat spectrum ball in that orbit don't we ?

    So , our disagreement is whether the classical calculation of incoming short wave solar absorptivity versus long wave emissivity has to be in the ratio I calculate if there is no internal heating ?

    You definitely ought to check out the Heartland Climatewiki page and correct any errors .

  79. Nope, David, I haven't agreed with those things. Instead, all these explanations of mine were meant to show that and why your reasoning is wrong and what is the right one.

    The average temperature of an object at a given distance from the Sun may deviate from your value in both directions and this temperature isn't uniform over the object but, as importantly manifested by the lapse rate, depends on the altitude - location within the object etc.

    There is no upper bound on the equilibrium temperature in principle, even at a given distance from the Sun. If an object is made to absorb the incoming sunlight but prevented from emitting its own radiation, the temperature will rise well above your naive estimate.

  80. Please read my http://cosy.com/views/warm.htm . It covers all your points quantitatively .

  81. As a conservative physicist I love your blog. Unfortunately there are many things you write about that I don't understand like "Strings" and Higgs Bosons. My field is quantum electro-optics; prior to retiring in 2002 I spent 12 years building "Free Electron Lasers" funded with DoD dollars. It is not "Rocket Science"; it is way more complicated given that it involved building relativistic particle accelerators to provide the "Working Fluid". Since retiring I do a little part time teaching which means I have far too much time on my hands.

    Most of what you say about the "Greenhouse Effect" above makes perfect sense. However, if you believe that gas composition has a significant influence on the surface temperature of rocky bodies you are mistaken. If we could miraculously replace the CO2 in the atmosphere of Venus with Helium to maintain the ~90 bar gas pressure at the surface, the temperature would not fall. If you believe otherwise, show me your calculations. Don't try the "Rubbish" bomb you dropped on David Burton Russell if you want to retain my respect.

    Remember that Venus has 100% cloud cover so you need to calculate the energy balance at the cloud tops as Carl Sagan did in the 1960s rather than at the surface itself.

  82. Ben,

    The "wellknown equation" that calculates Earth's average temperature "sans atmosphere" as 255 Kelvin would be correct for a planet composed of a thermal "Super Conductor". In other words it assumes that the surface temperature is uniform.

    While our oceans and atmosphere are very effective in distributing heat they cannot entirely eliminate temperature differentials between the equatorial regions and the poles. The differentials are more extreme on the Moon because it lacks oceans and atmosphere. Detailed measurements of the Moon's surface show that the average temperature of the equatorial regions is 206 Kelvin and the overall average is ~155 Kelvin.

    How could "Climate Scientists" with their "wellknown equation" be wrong by such a large margin (100 Kelvin)? While their equation is correct it should not be applied to bodies with large surface temperature differentials. As Lubos points out elsewhere surfaces at 400 Kelvin radiate 10,000 times more energy than ones at 40 Kelvin. Nikolov & Zeller are physicists rather than climate scientists so they have made an effort to explain planetary surface temperatures:

    Note that N&K calculate Tgb =154.3K for both the earth and the Moon. While we don't have a way to measure Tgb directly for Earth, the Diviner Experiment is in close agreement with theory in the case of the Moon.

  83. Ben,
    Lubos sent a reply a month ago that covered thermal capacity of the oceans and the transfer of heat into the oceans. When it comes to temperature gradients there is a relatively simple explanation based on thermodynamics:

    Temperature falls with increasing depth in the oceans until one reaches a temperature of ~4 degrees Centigrade at which point water reaches its maximum density. In the Arctic this temperature is reached near the surface, while in the tropics you may have to descend 1,000 meters. At greater depths the temperature will continue to fall slowly, reaching a minimum of ~1.2 Centigrade at 8,000 meters because the temperature of maximum density is a function of pressure.
    For a more scientific explanation please read this lecture that uses thermodynamics to derive lapse rates for the oceans and for the troposphere: