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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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The greenhouse effect and the 2nd law of thermodynamics

What the science says...

Select a level... Basic Intermediate

The 2nd law of thermodynamics is consistent with the greenhouse effect which is directly observed.

Climate Myth...

2nd law of thermodynamics contradicts greenhouse theory

 

"The atmospheric greenhouse effect, an idea that many authors trace back to the traditional works of Fourier 1824, Tyndall 1861, and Arrhenius 1896, and which is still supported in global climatology, essentially describes a fictitious mechanism, in which a planetary atmosphere acts as a heat pump driven by an environment that is radiatively interacting with but radiatively equilibrated to the atmospheric system. According to the second law of thermodynamics such a planetary machine can never exist." (Gerhard Gerlich)

 

At a glance

Although this topic may have a highly technical feel to it, thermodynamics is a big part of all our everyday lives. So while you are reading, do remember that there are glossary entries available for all thinly underlined terms - just hover your mouse cursor over them for the entry to appear.

Thermodynamics is the branch of physics that describes how energy interacts within systems. That interaction determines, for example, how we stay cosy or freeze to death. You wear less clothing in very hot weather and layer-up or add extra blankets to your bed when it's cold because such things control how energy interacts with your own body and therefore your degree of comfort and, in extreme cases, safety.

The human body and its surroundings and energy transfer between them make up one such system with which we are all familiar. But let's go a lot bigger here and think about heat energy and its transfer between the Sun, Earth's land/ocean surfaces, the atmosphere and the cosmos.

Sunshine hits the top of our atmosphere and some of it makes it down to the surface, where it heats up the ground and the oceans alike. These in turn give off heat in the form of invisible but warming infra-red radiation. But you can see the effects of that radiation - think of the heat-shimmer you see over a tarmac road-surface on a hot sunny day.

A proportion of that radiation goes back up through the atmosphere and escapes to space. But another proportion of it is absorbed by greenhouse gas molecules, such as water vapour, carbon dioxide and methane.  Heating up themselves, those molecules then re-emit that heat energy in all directions including downwards. Due to the greenhouse effect, the total loss of that outgoing radiation is avoided and the cooling of Earth's surface is thereby inhibited. Without that extra blanket, Earth's average temperature would be more than thirty degrees Celsius cooler than is currently the case.

That's all in accordance with the laws of Thermodynamics. The First Law of Thermodynamics states that the total energy of an isolated system is constant - while energy can be transformed from one form to another it can be neither created nor destroyed. The Second Law does not state that the only flow of energy is from hot to cold - but instead that the net sum of the energy flows will be from hot to cold. That qualifier term, 'net', is the important one here. The Earth alone is not a "closed system", but is part of a constant, net energy flow from the Sun, to Earth and back out to space. Greenhouse gases simply inhibit part of that net flow, by returning some of the outgoing energy back towards Earth's surface.

The myth that the greenhouse effect is contrary to the second law of thermodynamics is mostly based on a very long 2009 paper by two German scientists (not climate scientists), Gerlich and Tscheuschner (G&T). In its title, the paper claimed to take down the theory that heat being trapped by our atmosphere keeps us warm. That's a huge claim to make – akin to stating there is no gravity.

The G&T paper has been the subject of many detailed rebuttals over the years since its publication. That's because one thing that makes the scientific community sit up and take notice is when something making big claims is published but which is so blatantly incorrect. To fully deal with every mistake contained in the paper, this rebuttal would have to be thousands of words long. A shorter riposte, posted in a discussion on the topic at the Quora website, was as follows: “...I might add that if G&T were correct they used dozens of rambling pages to prove that blankets can’t keep you warm at night."

If the Second Law of Thermodynamics is true - something we can safely assume – then, “blankets can’t keep you warm at night”, must be false. And - as you'll know from your own experiences - that is of course the case!

Please use this form to provide feedback about this new "At a glance" section. Read a more technical version below or dig deeper via the tabs above!


Further details

Among the junk-science themes promoted by climate science deniers is the claim that the explanation for global warming contradicts the second law of thermodynamics. Does it? Of course not (Halpern et al. 2010), but let's explore. Firstly, we need to know how thermal energy transfer works with particular regard to Earth's atmosphere. Then, we need to know what the second law of thermodynamics is, and how it applies to global warming.

Thermal energy is transferred through systems in five main ways: conduction, convection, advection, latent heat and, last but not least, radiation. We'll take them one by one.

Conduction is important in some solids – think of how a cold metal spoon placed in a pot of boiling water can become too hot to touch. In many fluids and gases, conduction is much less important. There are a few exceptions, such as mercury, a metal whose melting point is so low it exists as a liquid above -38 degrees Celsius, making it a handy temperature-marker in thermometers. But air's thermal conductivity is so low we can more or less count it out from this discussion.

Convection

Convection

Figure 1: Severe thunderstorm developing over the Welsh countryside one evening in August 2020. This excellent example of convection had strong enough updraughts to produce hail up to 2.5 cm in diameter. (Source: John Mason)

Hot air rises – that's why hot air balloons work, because warm air is less dense than its colder surroundings, making the artificially heated air in the balloon more buoyant and thereby creating a convective current. The same principle applies in nature: convection is the upward transfer of heat in a fluid or a gas. 

Convection is highly important in Earth's atmosphere and especially in its lower part, where most of our weather goes on. On a nice day, convection may be noticed as birds soar and spiral upwards on thermals, gaining height with the help of that rising warm air-current. On other days, mass-ascent of warm, moist air can result in any type of convective weather from showers to severe thunderstorms with their attendant hazards. In the most extreme examples like supercells, that convective ascent or updraught can reach speeds getting on for a hundred miles per hour. Such powerful convective currents can keep hailstones held high in the storm-cloud for long enough to grow to golfball size or larger.

Advection

Advection is the quasi-horizontal transport of a fluid or gas with its attendant properties. Here are a couple of examples. In the Northern Hemisphere, southerly winds bring mild to warm air from the tropics northwards. During the rapid transition from a cold spell to a warm southerly over Europe in early December 2022, the temperatures over parts of the UK leapt from around -10C to +14C in one weekend, due to warm air advection. Advection can also lead to certain specific phenomena such as sea-fogs – when warm air inland is transported over the surrounding cold seas, causing rapid condensation of water vapour near the air-sea interface.

Advection

Figure 2: Advection fog completely obscures Cardigan Bay, off the west coast of Wales, on an April afternoon in 2015, Air warmed over the land was advected seawards, where its moisture promptly condensed over the much colder sea surface.

Latent heat

Latent heat is the thermal energy released or absorbed during a substance's transition from solid to liquid, liquid to vapour or vice-versa. To fuse, or melt, a solid or to boil a liquid, it is necessary to add thermal energy to a system, whereas when a vapour condenses or a liquid freezes, energy is released. The amount of energy involved varies from one substance to another: to melt iron you need a furnace but with an ice cube you only need to leave it at room-temperature for a while. Such variations from one substance to another are expressed as specific latent heats of fusion or vapourisation, measured in amount of energy (KiloJoules) per kilogram. In the case of Earth's atmosphere, the only substance of major importance with regard to latent heat is water, because at the range of temperatures present, it's the only component that is both abundant and constantly transitioning between solid, liquid and vapour phases.

Radiation

Radiation is the transfer of energy as electromagnetic rays, emitted by any heated surface. Electromagnetic radiation runs from long-wave - radio waves, microwaves, infra-red (IR), through the visible-light spectrum, down to short-wave – ultra-violet (UV), x-rays and gamma-rays. Although you cannot see IR radiation, you can feel it warming you when you sit by a fire. Indeed, the visible part of the spectrum used to be called “luminous heat” and the invisible IR radiation “non-luminous heat”, back in the 1800s when such things were slowly being figured-out.

Sunshine is an example of radiation. Unlike conduction and convection, radiation has the distinction of being able to travel from its source straight through the vacuum of space. Thus, Solar radiation travels through that vacuum for some 150 million kilometres, to reach our planet at a near-constant rate. Some Solar radiation, especially short-wave UV light, is absorbed by our atmosphere. Some is reflected straight back to space by cloud-tops. The rest makes it all the way down to the ground, where it is reflected from lighter surfaces or absorbed by darker ones. That's why black tarmac road surfaces can heat up until they melt on a bright summer's day.

Radiation

Figure 3: Heat haze above a warmed road-surface, Lincoln Way in San Francisco, California. May 2007. Image: Wikimedia Commons.

Energy balance

What has all of the above got to do with global warming? Well, through its radiation-flux, the Sun heats the atmosphere, the surfaces of land and oceans. The surfaces heated by solar radiation in turn emit infrared radiation, some of which can escape directly into space, but some of which is absorbed by the greenhouse gases in the atmosphere, mostly carbon dioxide, water vapour, and methane. Greenhouse gases not only slow down the loss of energy from the surface, but also re-radiate that energy, some of which is directed back down towards the surface, increasing the surface temperature and increasing how much energy is radiated from the surface. Overall, this process leads to a state where the surface is warmer than it would be in the absence of an atmosphere with greenhouse gases. On average, the amount of energy radiated back into space matches the amount of energy being received from the Sun, but there's a slight imbalance that we'll come to.

If this system was severely out of balance either way, the planet would have either frozen or overheated millions of years ago. Instead the planet's climate is (or at least was) stable, broadly speaking. Its temperatures generally stay within bounds that allow life to thrive. It's all about energy balance. Figure 4 shows the numbers.

Energy Budget AR6 WGI Figure 7_2

Figure 4: Schematic representation of the global mean energy budget of the Earth (upper panel), and its equivalent without considerations of cloud effects (lower panel). Numbers indicate best estimates for the magnitudes of the globally averaged energy balance components in W m–2 together with their uncertainty ranges in parentheses (5–95% confidence range), representing climate conditions at the beginning of the 21st century. Figure adapted for IPCC AR6 WG1 Chapter 7, from Wild et al. (2015).

While the flow in and out of our atmosphere from or to space is essentially the same, the atmosphere is inhibiting the cooling of the Earth, storing that energy mostly near its surface. If it were simply a case of sunshine straight in, infra-red straight back out, which would occur if the atmosphere was transparent to infra-red (it isn't) – or indeed if there was no atmosphere, Earth would have a similar temperature-range to the essentially airless Moon. On the Lunar equator, daytime heating can raise the temperature to a searing 120OC, but unimpeded radiative cooling means that at night, it gets down to around -130OC. No atmosphere as such, no greenhouse effect.

Clearly, the concentrations of greenhouse gases determine their energy storage capacity and therefore the greenhouse effect's strength. This is particularly the case for those gases that are non-condensing at atmospheric temperatures. Of those non-condensing gases, carbon dioxide is the most important. Because it only exists as vapour, the main way it is removed is as a weak solution of carbonic acid in rainwater – indeed the old name for carbon dioxide was 'carbonic acid gas'. That means once it's up there, it has a long 'atmospheric residency', meaning it takes a long time to be removed. 

Earth’s temperature can be stable over long periods of time, but to make that possible, incoming energy and outgoing energy have to be exactly the same, in a state of balance known as ‘radiative equilibrium’. That equilibrium can be disturbed by changing the forcing caused by any components of the system. Thus, for example, as the concentration of carbon dioxide has fluctuated over geological time, mostly on gradual time-scales but in some cases abruptly, so has the planet's energy storage capacity. Such fluctuations have in turn determined Earth's climate state, Hothouse or Icehouse – the latter defined as having Polar ice-caps present, of whatever size. Currently, Earth’s energy budget imbalance averages out at just under +1 watt per square metre - that’s global warming. 

That's all in accordance with the laws of Thermodynamics. The First Law of Thermodynamics states that the total energy of an isolated system is constant - while energy can be transformed from one component to another it can be neither created nor destroyed. Self-evidently, the "isolated" part of the law must require that the sun and the cosmos be included. They are both components of the system: without the Sun as the prime energy generator, Earth would be frozen and lifeless; with the Sun but without Earth's emitted energy dispersing out into space, the planet would cook, Just thinking about Earth's surface and atmosphere in isolation is to ignore two of this system's most important components.

The Second Law of Thermodynamics does not state that the only flow of energy is from hot to cold - but instead that the net sum of the energy flows will be from hot to cold. To reiterate, the qualifier term, 'net', is the important one here. In the case of the Earth-Sun system, it is again necessary to consider all of the components and their interactions: the sunshine, the warmed surface giving off IR radiation into the cooler atmosphere, the greenhouse gases re-emitting that radiation in all directions and finally the radiation emitted from the top of our atmosphere, to disperse out into the cold depths of space. That energy is not destroyed – it just disperses in all directions into the cold vastness out there. Some of it even heads towards the Sun too - since infra-red radiation has no way of determining that it is heading towards a much hotter body than the Earth,

Earth’s energy budget makes sure that all portions of the system are accounted for and this is routinely done in climate models. No violations exist. Greenhouse gases return some of the energy back towards Earth's surface but the net flow is still out into space. John Tyndall, in a lecture to the Royal Institution in 1859, recognised this. He said:

Tyndall 1859

As long as carbon emissions continue to rise, so will that planetary energy imbalance. Therefore, the only way to take the situation back towards stability is to reduce those emissions.


Update June 2023:

For additional links to relevant blog posts, please look at the "Further Reading" box, below.

Last updated on 29 June 2023 by John Mason. View Archives

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Comments 476 to 500 out of 1613:

  1. Tom Curtis @ 471: It appears to me that you are confusing the mechanisms responsibly for a planetary average temperature with those determining with the average temperature distribution across a planet. These two types of mechanisms are very different. Let me explain: The average near-surface temperature on a planet is a linear function of the total internal energy in the lower atmosphere. Therefore, that temperature can only be changed by increasing or decreasing the total internal energy. Winds, thermal inertia, axial rotational speed and other heat-transfer mechanisms on the surface of a planet only serve to redistribute that total energy, but do not change its overall amount. As a result these mechanisms can only affect the degree of uniformity of the equilibrium temperature field, but cannot change the planetary mean temperature. This follows from the law of conservation of energy (First Law of thermodynamics), for any change of average temperature requires a net change in total internal energy. I'm working as fast as I can to complete my manuscript and submit it for publication. But it takes time to explain in a clear yet bullet-proof way the new concept, simply because there has been at least one whole generation of scientists indoctrinated into the wrong paradigm. The situation is analogous to that described in this legend, where American Indians could not see at first Columbus's ships on the horizon, because they had no mental concept of what a sail ship is. It wasn't until the local shaman explained to them the new 'event' in terms they could understand that they were able to see the ships (I think this legend was portrayed in the movie "What the Bleep Do We Know"). In other words, what we believe in and are accustomed to (i.e. our worldview) determines to large extend our ability to see or not certain things. In no way am I implying that I'm the 'shaman' here and everybody else represents the 'unenlightened Indians'! The new concept I'm presenting in the paper is actually quite simple (since it's rooted in physical principles that are 150 years old). BUT it does require a shift in perception in order to fully grasp it. That is in part why it constitutes a new paradigm... :) NO, I'm not planning to submit it to E&E, although this journal has published a number of articles that have brought some important valid points to the climate debate. I can bring up a similar objection with respect to Nature as well, since that journal has published the hockey-stick temperature paper by Michael Mann & Co in 1998, which has been since discredited for its [snipped] statistical analysis both in the peer-reviewed literature and at Congressional hearings (Note that IPCC is longer using the hockey-stick graph).
    Response: Your claims about the hockey stick are incorrect. Regarding your claim that the hockey stick has been discredited, see the Argument "Hockey stick is broken." Regarding your claim that the IPCC is no longer using the hockey stick graph, you can see the hockey stick just by looking in the 2007 IPCC report itself!
  2. "(Note that IPCC is longer using the hockey-stick graph)." You may have to add a few pages to your monograph to elaborate on your claims about this aspect of the science. It will be a lot of pages in fact. Lotta hockey sticks here
  3. scaddenp @ 474: The short answer to your question is YES - my new theory fully accounts for known observational results AND is in full compliance with standard thermodynamics theory, which is not the case with the current GH concept as I explained in #458. It also perfectly predicts the observed temperatures on hard-surface planets in the solar system! This is actually one of the main strengths of the new theory ... Ladies & Gents, I will be leaving you now for a while, since I've got work to do and have already stirred enough the pot for couple days ... Keep thinking about this discussion in an open-minded way and wait till my paper is published ... We will continue the discussion then. Good luck to all of you!
  4. adelady @ 477: Sorry for the missing word in that sentence. What I meant was "(Note that IPCC is no longer using the hockey-stick graph)" .. The problem of perception in scientific inquiry is a psychological issue and a topic of another discussion ...
    Response: Your change in phrasing doesn't make your claim correct. You have been pointed to the Skeptical Science thread where your claim is rebutted, and where you must post any further comments on that particular topic.
  5. I hope the answer is still YES to my actual question not your rephrasing of it. ie "do you also accept the principle that your claims must account for empirical results? Ie if the textbook interpretation of thermodynamics accounts for observation results and yours do not, then perhaps the textbook is correct and you need to do more reading? " You have untold empirical mountains to climb and excuse my extreme skepticism until that is presented. My money is on you not being able to get published given what you said to date.
  6. PhysSci (RE: 458), "If the GH effect were due to absorption and re-emission of IR energy by greenhouse gases ultimately traceable to solar input as claimed by the current theory, then how is it possible that the down-welling thermal flux exceeds the total solar input by 44% (343/239 = 1.44)." This is not correct. The downward emitted flux is only about 150 W/m^2. The surface on average emits about 390 W/m^2. About 90 W/m^2 passes through unabsorbed and goes straight out to space. About 300 W/m^2 is absorbed and re-emitted by the atmosphere, of which half goes up and half goes down (150 W/m^2 up and 150 W/m^2 down).
  7. PhysSci (RE: 459), "As I said in my previous posting, the lower troposphere contains more energy than supplied by the Sun. Where is that energy coming from?" It's coming back from the atmosphere. The rate at which the energy is coming in from the Sun is faster than the rate at which it's able to leave to planet. In essence it takes 1.6 W/m^2 at the surface to allow each 1 W/m^2 to leave the planet, offsetting each 1 W/m^2 entering the system from the Sun. (390 W/m^2 at the surface divided by 239 W/m^2 from the Sun = 1.6).
  8. PhysSci, BTW, I agree that Conservation of Energy is the biggest Achilles heel of the entire CO2/AGW theory but not for the reasons you claim.
  9. PhysSci, "Why do variations in global temperature over the past 27 years correlate much better with observed changes in cloud albedo than with those in GH gases?" My guess is because the temperatures are tied mostly to the available energy in the system (i.e. the amount of post albedo energy from the Sun), rather than GHG concentrations or atmospheric opacity.
  10. Response to RW1 @ 481: Forgive me, but comments like yours make me smile and really wonder what's the level of scientific expertise on this blog?... A global down-welling thermal flux of over 320 W m-2 has been extensively measured and confirmed by both satellite and surface observations for 15 years now! The actual estimates vary between 324 and 348 W m-2. This is now considered a basic information about Earth's radiation budget!! Here are some references (in chronological order) to help you update your knowledge base on this: Rossow, W. B. and Zhang, Y.C. 1995. Calculation of surface and top of atmosphere radiative fluxes from physical quantities based on ISCCP data sets, 2, Validation and first results, J. Geophys. Res., 100, 1167–1197. Trenberth, K. E. 1997. Using atmospheric budgets as a constraint on surface fluxes. J. Climate, 10, 2796–2809. Gupta, S. K., Ritchey, N. A., Wilber, A. C., and Whitlock, C. A. 1999. A Climatology of Surface Radiation Budget Derived from Satellite Data, J. Climate, 12, 2691–2710. Pavlakis, K. G., D. Hatzidimitriou, C. Matsoukas, E. Drakakis, N. Hatzianastassiou, and I. Vardavas. 2003. Ten-year global distribution of downwelling longwave radiation. Atmos. Chem. Phys. Discuss., 3:5099-5137. Trenberth, K.E., J.T. Fasullo, and J. Kiehl. 2009. Earth’s global energy budget. BAMS, March:311-323 Also, look at the NASA's Surface Radiation Budget (SRB) project page, where you can get global maps of LW and solar fluxes on a monthly basis for 24 years, where you'll clearly see that LW fluxes at the surface exceed incoming SW fluxes by a large margin: http://mynasadata.larc.nasa.gov/las/servlets/dataset?catitem=21
  11. PhysSci, "Forgive me, but comments like yours make me smile and really wonder what's the level of scientific expertise on this blog?... A global down-welling thermal flux of over 320 W m-2 has been extensively measured and confirmed by both satellite and surface observations for 15 years now! The actual estimates vary between 324 and 348 W m-2. This is now considered a basic information about Earth's radiation budget!!" I'm not referring to the total downward flux, but the downward amount that last originated from the surface emitted. I think you're forgetting that a good amount of incoming solar energy is absorbed by the atmosphere/clouds and emitted down toward the surface. Conservation of Energy dictates that the downward emitted amount that last originated from the surface cannot be 300+ W/m^2. If you are claiming this is so, show me the power in = power out calculations that prove it.
  12. General Response to RW1: RW1, I suggest you stop embarrassing yourself with comments like the ones you made in 482 to 484 ... I'm not even going to respond to a such a profound lack of understanding. You are totally excused, if you are not a scientist, but if you are, then you've got a BIG problem with basic physics ... Thank you for participating and good luck!
  13. PhysSci, Sorry, clarification to my own #481, I meant 'back radiation'- meaning the downward emitted that last originated from the surface.
  14. PhysSci, "RW1, I suggest you stop embarrassing yourself with comments like the ones you made in 482 to 484 ... I'm not even going to respond to a such a profound lack of understanding. You are totally excused, if you are not a scientist, but if you are, then you've got a BIG problem with basic physics ..." Sorry, you're going to have to do better than that.
  15. PhysSci, "RW1, I suggest you stop embarrassing yourself with comments like the ones you made in 482 to 484" #484 I was guessing. #482 - are you claiming that the post albedo energy of 239 W/m^2 does NOT become about 390 W/m^2 at the surface? Are you claiming that 390/239 is NOT about 1.6? Are you claiming that this does NOT mean that it takes 390 W/m^2 at the surface to allow 239 W/m^2 to leave the planet, offsetting the 239 W/m^2 entering? If yes, please explain why in detail and then we'll discuss via give and take.
    Response: [muoncounter] Please be aware that this is not necessarily the best forum for such give and take. Much of this detail has already been the subject of numerous comments, both on this thread and climate sensitivity threads.
  16. From Trenberth, Fasullo and Kiel (2009): Globally averaged incoming SW radiation at the Earth's surface is shown to be 184 w/m^2, of which 23 w/m^2 are relfected back to space. Total backradiation (all sky downward long wave flux) globally averaged is 333 w/m^2. Total upwelling engergy from the Earth's surface, globally averaged is 17 w/m^2 (thermals) plus 80 w/m^2 (evapotranspiration) plus 396 w/m^2 (upwelling long wave radiation), or 493 w/m^2. Downward = SW + LW = 161 + 333 = 494, the difference between them being the net absorbed. So, no contradiction of conservation of energy involved. That wasn't so hard, was it?
  17. "Globally averaged incoming SW radiation at the Earth's surface is shown to be 184 w/m^2, of which 23 w/m^2 are relfected back to space. Total backradiation (all sky downward long wave flux) globally averaged is 333 w/m^2. Total upwelling engergy from the Earth's surface, globally averaged is 17 w/m^2 (thermals) plus 80 w/m^2 (evapotranspiration) plus 396 w/m^2 (upwelling long wave radiation), or 493 w/m^2. Downward = SW + LW = 161 + 333 = 494, the difference between them being the net absorbed. So, no contradiction of conservation of energy involved." But latent heat and thermals are kinetic (not radiative) - meaning their energy moved into the atmosphere didn't come from from surface emitted radiation. So even assuming all the latent heat and thermal energy is ultimately returned to the surface as downward emitted radiation (highly unlikely), the net effect is zero relative to surface emitted radiation. It has to be for Conservation of Energy to be met. The bottom line is only about 150 W/m^2 of the surface emitted radiation can be returned as 'back radiation'. By 'back radiation' I specifically mean radiation that last originated from surface emitted (this is a key distinction, especially since all the energy ultimately originated from the Sun). You do know that the surface emitted radiation of about 390 W/m^2 is directly due to its temperature and nothing else, right?
  18. If you notice, even Trenberth is showing 169 W/m^2 emitted by the atmosphere and 70 W/m^2 passing through completely unabsorbed (40 W/m^2 through the atmosphere, 30 W/m^2 through the clouds) for 239 W/m^2 leaving. This means that of the 396 W/m^2 emitted by the surface, using Trenberth's numbers at least, 157 W/m^2 of it has to be 'back radiation' from the atmosphere. He's obfuscating this by absorbing some of the post albedo energy by the atmosphere and returning it as 'back radiation' when it's really 'forward radiation' that last originated from the Sun - not the surface. He's then returning the latent heat and thermals as 'back radiation' to come up with at total downward emitted of 333 W/m^2, which he incorrectly designates as being all 'back radiation'. It's a mess.
  19. 161 W/m^2 + 78 W/m^2 = 239 W/m^2 post albedo at the surface. 239 W/m^2 from the Sun + 157 W/m^2 downward emitted from the atmosphere = 396 W/m^2 emitted by the surface.
  20. The moderator of this website has an agenda to prevent a free and open discussion on important subjects. He deletes postings that are totally relevant to the subject at hand but do not conform to his ideology or agenda.
    Response: Discussion of hockey sticks and the little ice age are not relevant to this thread. You have already been pointed to the appropriate threads for discussion of these topics, feel free to post your comments there.

    In addition, your latest comments have been peppered with inflammatory invective. This will not be tolerated. You are a guest on this site, and as such you are expected to abide by this site's comment policy. Please try and behave like a mature adult if you want to be taken seriously.
  21. The moderators, plural, at this site ensure that the contributions from all of us conform to the Comments Policy... This might mean that this comment disappears along with your #495 but that doesn't matter. To comply with the policy, your statements must avoid politics, accusations of dishonesty, against anyone, and your scientific statements have to have some backing or reference to the scientific literature. You've set yourself a difficult task in trying to overturn 150 years of physics and nearly as many years of observations from glaciology, biology and the rest. But if your science is sound, you should be able to point out scientific references that support whatever limited statements you do make about your new theory. There is an agenda. "Stick to the science" best describes it. There are some exceptions but this thread isn't one of them.
  22. RW1 @492-5, "First of all, what is “back-radiation” ? It’s the radiation emitted by the atmosphere which is incident on the earth’s surface. It is also more correctly known as downward longwave radiation – or DLR" There is nothing in that definition that depends on the original source, or penultimate source of the energy in the Downward Longwave Radiation, and with good reason. If you want to use some different concept other than DLR, then find your own term and define it clearly. Don't lazilly misuse an already defined technical term and then accuse people who are using it correctly of doing so incorrectly. Not only is it lazy, it is bound to cause confusion for other when they try to understand you; and yourself when you do the same. The very good reason why back radiation is DLR only is that, when a GHG emits IR radiation, it does not have a phycical state correlating to the penultimate source of the energy it is about to emit. It only has the energy itself. Therefore it can make no difference to the properties of that emitted radiation whether that energy was originally carried into the atmosphere by evaporation, or convetion, or IR radiaton from the ground, of from volcanic emissions, or what ever. Indeed, as most energy transfers in the astmosphere are by collision, it is doubtfull you can say sensibly of any parcel of energy what its penultimate source was. Therefore, energy carried into the atmosphere by evapotranspiration will be radiated to the surface, or to space in the exact ratios as energy carried into the atmosphere by IR radiation, or energy absorbed from SW radiation from the sun. Trying to treat it as a discrete entity after it has been carried into the atmosphere is, scientifically, gobbledy-gook. To finish, Trenberth, Khiel and Fasullo are not obfusticating by indicating some SW radiation is absorbed in the atmosphere. They are describing an indirect emperical result, and one that is more easily determined than, for example the proportion of SW light reflected from clouds, or from the surface. The method is to measure downward SWR at the Top of the Atmosphere, upward SWR at the TOA, and subtract the later from the former. You then measure downward SWR at the surface, and subtract that result from the difference; giving you the amount of SWR absorbed. (Clearly the measurements need to be made at a large number of points and times to determine a global average.) T,K, & F (2009) list a summary of such mesurements on table 2b. It is a telling indictment of your "science" that you cannot use standard definitions correctly, and have to dismiss observational results as "obfustications".
  23. To demonstrate the equivalence of work and energy, elementary physics uses the example of a paddle wheel in a gas filled, insulated container, driven by a falling weight. (Page 51 of Schaum’s Themodynamics for Engineers, since this blog likes references) The potential energy of the weight is converted to kinetic energy as the weight falls, and the rotation of the paddle works on the gas content, increasing its temperature. Neglecting frictional losses, the energy content of the gas (its temperature increase) is equal to the potential energy of the weight. The questions that really elementary Physics does not ask, are these: Is it possible to use the additional energy in the gas to restore the weight to its original position? If not, why not? It is not possible because the quality of the energy has changed. It has been dispersed throughout the gas and, unlike the energy of the weight, its possible use is very limited. To recover the energy, even in principle, we would need to treat the gas as a source of energy, and connect it to a sink at a lower temperature. Energy could then be transferred, and some work could be done to raise the weight, but we would have to discharge most of the additional gas energy into the sink, so the weight would not rise very far. If this concept of energy quality is acceptable to advocates of atmospheric back-warming, we can go on to debate that proposition.
  24. Fred Staples @499, contrary to your claim in 498, your "proof" of the second law of thermodynamics is nothing but hand waving. It seems plausible, and we believe it to be true; but we do so because we are assuming heat loss to the environment through friction, air resistance and imperfect insulation. Absent those assumptions, ie, in an ideal system, it is not clear that the increased pressure and temperature could not be converted to work and raise the weight to its original position. Your merely asserting this is not the case does not constitute proof, and is, contrary to your claim, hand waving. Having said that, why not simply appeal to the second law of thermodynamics:
    "When two isolated systems in separate but nearby regions of space, each in thermodynamic equilibrium in itself, but not in equilibrium with each other at first, are at some time allowed to interact, breaking the isolation that separates the two systems, and they exchange matter or energy, they will eventually reach a mutual thermodynamic equilibrium. The sum of the entropies of the initial, isolated systems is less than or equal to the entropy of the final exchanging systems. In the process of reaching a new thermodynamic equilibrium, entropy has increased, or at least has not decreased."
  25. How can anybody learn anything from the supposed heat transfer shown in the diagram in #491? The author who drew this failed to provide any temperature information anywhere. How can he possibly know the energy tranfers (all over the diagram in W/m^2) without indicating the temperatures? Whoever drew this diagram obviously hadn't the slightest knowledge of the 2nd Law of Thermodynamics. Who pays money for 'stuff' like this? It is the appearance of dagrams like this in IPCC reports that makes one instinctively mistrust all of 'global temperature increase' figures produced by the IPCC.

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