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Waste heat vs greenhouse warming

Posted on 27 July 2010 by John Cook

A vigorous discussion has erupted on the waste heat page. Problem is, there's not meant to be a waste heat page! As I encounter new skeptic arguments, I add them to the to-do list and gradually (very gradually) research the peer-reviewed literature then write an explanation of what the science says, usually in order of popularity. I hadn't got around to looking into the issue of waste heat. Nevertheless, one intrepid Skeptical Science user found the empty page waiting to be populated and began a discussion there (j'accuse Doug Bostrom). So let's look at waste heat...

Firstly, what is waste heat? When humans use energy, it gives off heat. Whenever we burn fossil fuels, heat is emitted. This heat doesn't just disappear - it dissipates into our environment. How much does waste heat contribute to global warming? This has been calculated in Flanner 2009 (if you want to read the full paper, access details are posted here). Flanner contributes that the contribution of waste heat to the global climate is 0.028 W/m2. In contrast, the contribution from human greenhouse gases is 2.9 W/m2 (IPCC AR4 Section 2.1). Waste heat is about 1% of greenhouse warming.

Radiative forcing from waste heat vs anthropogenic greenhouse gas radiative forcing

What do these numbers mean? They refer to radiative forcing, the change in energy flux at the top of the atmosphere. Or putting it in plain English, the amount of heat being added to our climate. Greenhouse warming is currently adding about 100 times more heat to our climate than waste heat.

UPDATE 27 July: there is some confusion about the term 'waste heat'. Here, what I'm talking about is all the heat generated by energy use. When humans generate energy, much of it is immediately dissipated as heat. The rest is converted to electricity or energy of some sort (eg - mechanical, chemical, etc). But even this energy eventually dissipates as heat into the environment. So yes, 'waste heat' is not an ideal term. Flanner uses the term "anthropogenic heat flux".

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Comments 51 to 100 out of 431:

  1. KR writes: There's no Maxwell's demon choosing joules of heat energy based on their origin Excellent reference, much better than my Heat Fairy above. RSVP, maybe it would help if I could try to summarize your argument? Tell me if I have this right: (1) Waste heat is efficiently shunted to the atmosphere, particularly to N2 and O2 molecules which, not being radiatively active, retain the heat, distribute it around the earth, and let it accumulate. (2) In contrast, the radiative forcing from CO2 is overstated because (a) Part of the radiation isn't captured, and escapes into space. (b) The rest of it is just captured by CO2 molecules, which re-emit it, eventually letting it escape to space, so it doesn't accumulate. Is that a good first approximation of your argument? What parts am I not quite getting?
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  2. dcwarrior, yep that's about the shape of it. The only thing which isn't clearly stated (though it may be what you meant) from your summation is that the increasing CO2 doesn't create additional heat directly... rather it slows down the rate at which heat escapes to space. Since more energy is always coming in from the Sun if the rate of energy escape decreases then the total energy in the Earth's climate must increase.
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  3. CBDunkerson @52, you should add to the end of your statement that the energy in the Earth's climate must increase *until a new equilibrium is reached*, since the amount of energy that escapes is a function of the temperature. If CO2 (and everything else) was held constant, then we'd warm up asymptotically to some equilibrium (assuming we don't hit some non-linear feedback before we get there). But, of course, CO2 isn't being held constant, so the equilibrium point is moving away from us even as we chase it.
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  4. dcwarrior at 04:00 AM on 28 July, 2010: "the CO2 greenhouse effect works by adding small amounts of CO2 to the atmosphere faster than the natural processes get rid of it" Almost. ;) The greenhouse effect is already present because there's already CO2 (and other greenhouse gases) in the atmosphere. What happens is that the greenhouse effect is increased because we put more CO2 in the air than nature can handle. And it's a lot: "Currently, humans are emitting around 29 billion tonnes of carbon dioxide into the atmosphere per year. Around 43% remains in the atmosphere - this is called the 'airborne fraction'. The rest is absorbed by vegetation and the oceans." (Are CO2 levels increasing?)
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  5. "Waste heat" has always been somewhat of a misleading term. Perhaps that is why it is used freely in engineering course on thermodynamics, but almost never in physics courses;) The reason it is misleading is because heat, qua heat, is always the same: 'waste' heat and 'useful' heat are physically indistinguishable. The distinction can only be made in a process: the waste heat is the heat you cannot use in the process to do work. It has to be dumped into the environment to dispose of entropy. But there is another kind of 'waste heat, much easier to define: the heat generated in this thread, which is certainly a waste;)
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  6. CBDunkerson #47 "The latter. No one comprehends it... because it is self-evidently false. 2 is 2, up is not down, and watts are watts." Yes watts are watts, but I am sure you comprehend when paying your energy bill if the watts refers to consumption over 1 month, 2 months or one year.
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  7. RSVP - I'm afraid that your last comment has left me scratching my head in puzzlement. What in the world are you talking about?!? No matter what the energy expenditure, it ends up as heat. It might be fast (car radiator), it might be really slow (decomposition of manufactured plastic), it might be IR or even latent heat (water vapor from power plant cooling tower) - but it all ends up as heat. As watts (or more properly joules - 1 watt is 1 joule/second). Direct expenditures (waste heat) end up in the atmosphere or waters within minutes (both IR or convection), energy used (electricity, for example) takes a bit longer. Joules are not stamped with ID tags, any more than photons are. Watts are Watts. If you can't explain your issue more clearly I'm just going to have to say I don't understand your objection.
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  8. Ned 51 Your point #1 "resembles" what I have said, yet why do you have to reword my words when most of what I have said about this has not been deleted. (last time I looked :) Along those lines, I have also asked (more than once) how much of the 2.9 W/m2 caused by GHG is actually assumed to be accumulating? The notion that so much energy isnt raising daytime temperatures as we speak is baffling. What exactly does this number represent in terms of cumulative warming? As I said earlier, if it means no overall accumulation, then maybe even 0.028 W/m2 for waste heat is huge if that heat is accumulating, which gets back to the differnces between radiative and convective mechanisms. As this discussion has gone around circularly three or four times now, I am checking out.
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  9. RSVP - the 2.9 W/m^2 GHG forcing + the 0.028 W/m^2 AHF (total of 2.928 W/m^2) is accumulating, hence increasing temperatures, ocean heat content, earlier seasons, etc. It's just that the 0.028 AHF is small change in that sum. It's all indistinguishable energy once it goes into the pot. I don't think matters can get clearer than that. If you can't follow that paragraph, well, it's end of discussion for me.
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  10. For those of you new to the thread, a bit of an outline. There are various forcings changing the energy level at the surface of the Earth. - Solar input (slightly decreasing slope over the last 30 years) - GHG entrapment (+2.9 W/m^2 retaining solar energy right now) - Aerosols (est. -1.9 W/m^2 via reflecting sunlight, although it's influence is decreasing with pollution controls) - Anthropogenic heat flux (AHF), direct heat from our energy use (est 0.028 W/m^2, albeit highly concentrated at industrial centers, as per this thread) Tied to these direct forcings are feedbacks: water vapor levels, temperature dependent carbon uptake/release from the oceans, vegetation changes with temperature, albedo changes with ice melt, and so on. But the forcings that push temperatures away from current levels are the sum of the direct forcings such as listed above. And hence the discussion of the small influence AHF has with regards to greenhouse gasses.
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  11. KR, I am sure you noticed, but when I added 2.9W/m2 + .028 W/m2 and then round to significant figures I get 2.9 W/m2. The waste heat is so small it doesn't change the result! RSVP: There is NO DIFFERENCE in heat released by radiation and heat released by convection. Your argument is completely mistaken. Heat is heat. They are the same. Most of the commentors here are having trouble responding to you because this is such a basic issue that they don't understand your confusion. Good luck with this argument. I just read the whole thing (and participated in past discussions of this issue) and the deniers cannot accept basic, well understood, high school chemistry and physics. How can we move on to real issues that require an understanding of the science?
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  12. OT but along the lines of what I was musing on in the other waste heat thread... Not to pick on RSVP in particular but if we don't see some acknowledgment here that it's possible to upload facts into another person's head regardless of predisposition I'm left to wonder whether there's any point to comments on a site like SkS other than entertainment. I'm not sure if John keeps stats on this but my intuition tells me genuine puzzlement is exceedingly rare here, at least of the sort that is not founded on diamond-hard obduracy due to matters not having to do with science. Come to think of it, a person popped up on anther thread very loudly proclaiming the Stefan-Boltzmann constant to be all wet and in fact calmed down and seemed to take on board some explanations by BP and Ned. So I guess it's possible to effect improvements, I just wonder how often.
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    Moderator Response: I have anecdotal evidence that a persistent, calm presentation of the science and evidence does have a tangible effect. Not sure that it's a big effect but I have corresponded with a few people who have gone from being skeptical about man-made global warming to convinced that humans are causing global warming via the content on my site. Of course, they all still resist aggressive action on mitigation but hey, one step at a time.
  13. Thank you John, and the Stefan-Boltzmann example serves nicely to illustrate your point. Everybody came away happier, and calmer. Sorry for the interruption in normal programing!
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  14. Ray Pierrehumbert pretty well killed this one off in his letter to Levitt
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  15. Doug, I think your contributions in particular are valuable here on SS. I read much more frequently than I post and your well referenced arguments have helped me to discuss these issues with my high school students. I am more informed because of the material I learn from you when I am silent. I think that there are a lot of people who silently read and begin to understand the science even when you cannot make headway with someone on a thread. Thank you for your help.
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  16. #57, KR: You are illustrating the very confusion I commented about: no, it does NOT "all end up as heat". Some of it is converted to work. 'Work' includes phase changes, i.e. heating water to boil it. Even the whole Earth, accepting radiative energy in low entropy form from the sun and radiating it out into space in higher entropy form, has done work on it, building up the ever more complicated ecosystem -- including us. So far, human civilization is winning the battle against entropy. That could change fast under the influence of climate change as war, famine and pestilence tear down what we built up over thousands of years.
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  17. MattJ - I was trying to take the long view; almost every building put up will eventually get torn down. Of course, anything that goes into a long term or permanent state change doesn't add to the AHF, making it even less of a problem!
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  18. dcwarrior: "The Ville, I think you are factually correct, but I don't think someone who didn't already agree with you would be convinced by that argument." The Ville: Well if that were true and you are probably correct, then there is a lot of work to do. The basic science is not debatable so if it is doubted or questioned then there are serious problems in communication and education. Of course some people exploit that lack of knowledge. It may not be believed, as you say, but the science that the facts are based on isn't just isolated to climate science. The same science (basically quantum mechanics) is fundamental to medicine, engineering, electronics, IR spectroscopy etc. So maybe if someone has doubts, then you can correct them and point that out!
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  19. Doug, When you have a discussion with someone and put them right on something, don't expect them, necessarily, to roll over and declare, "OK, Doug, I'm wrong -- you were right all along". People will often argue to the bitter end, then we all move on with the topic seemingly unresolved. However next time the topic comes up you might suddenly notice that their opinions have changed -- in fact they did listen and did take on-board what you said. The magnanimous amongst us don't make a big deal of this, we just let it go. Not being a scientist, I don't mind being wrong about science or misunderstanding things. One of the best ways to learn or to test one's understanding is, rather than ask a question, to make a statement and see what reaction it gets. Good teachers tell you you're right or, if you've misunderstood, will just explain the facts in simpler terms. What they will never do is belittle the person making the statement. I suppose what I'm saying is that, apart from the occasional small sign that the message is getting through, one will never know for certain how effective a site like this is in changing people's opinions. What one can say for certain though is that it's a lot more influential than any of us will ever know.
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  20. dcwarrior: Further to my last comment to you, your response and adding to what others have said, there's an analogy that we've used before. I'll try to extend it. Imagine Earth as a bucket full of water. Energy from the sun is a tap that is pouring into this bucket from above and this flow is mixing with what's already in the bucket and the excess is spilling over the sides at the same rate. So the water level stays the same; the bucket/Earth is in equilibrium and humans at the bottom of the bucket live under a constant pressure (analogous to the Earth's global temperature). However since the industrial revolution humans have been putting more CO2 into the air, raising the concentration of GHGs, trapping energy; and therefore, in our analogy, we've been raising the sides of the bucket. This increases the pressure (temperature) at the bottom. So where does 'waste heat' fit in? Waste heat is as if humans at the bottom of the bucket had being indulging in activities -- don't ask me what; I've already stretched this analogy way too far -- which are producing a small amount of water as a by-product. That extra water is adding to the water from the big tap in the sky but is a tiny amount and is escaping over the sides with the rest of the water. What really matters though is the rising sides -- that's what's upping the pressure on life on Earth.
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  21. For those of you new to the thread, a bit of an outline. 1) We know (more or less) for sure how much energy is being expended by humans through the burning of fossil fuels. For this discussion, we call this total amount "waste heat". 2) One side of the debate claims that this energy enters the environment in different ways (see 3 for an example) and that this makes a difference in terms of global warming. The other side discounts this claim, saying "watts is watts is watts", and since the amount of waste heat is known to represent only 1% of the purported value due to the effects of anthropogenic greenhouse gases, it can be safely ignored. (somewhere above it has even been claimed that in a few hundred years waste heat wont exist at all as technology becomes more efficient. And perhaps (non nuclear) human waste heat will not exist, but it will likely be for other reasons...getting way off topic). 3) a) When a nuclear power plant is cooled by circulating sea water, the warmed water mixes below the surface of the sea. These "watts is watts" are carried with the current and may take years (or centuries) to finally radiate into the outer reaches of space. b) Convective heat exchange from the heating and cooling of buildings, or the cooling of internal combustion engines directly raises the temperature of non-GHGs (the bulk of what makes up the Earths atmosphere). Since non-GHG do not radiate, as with the warmed water from the nuclear power plant, this heat must find its way to the radiative launch pad, queuing up behind an already solar energized warm Earth. This cumulative back log is the real cause of global warming. 4) Watts is watts yes, but the problem is not about whether watts are watts. The problem is about global warming.
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  22. RSVP writes: Your point #1 "resembles" what I have said, yet why do you have to reword my words when most of what I have said about this has not been deleted. (last time I looked :) I have found that when trying to understand someone else it often helps if I can try to rephrase their information/argument in my own words. The secondary reason is that a lot of people here don't seem to be getting your point, and I thought that perhaps by having someone else try to clarify it we might make some progress. RSVP continues: Along those lines, I have also asked (more than once) how much of the 2.9 W/m2 caused by GHG is actually assumed to be accumulating? All of it. That's what a "climate forcing" is.
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  23. RSVP writes: Since non-GHG do not radiate, as with the warmed water from the nuclear power plant, this heat must find its way to the radiative launch pad, queuing up behind an already solar energized warm Earth. This cumulative back log is the real cause of global warming. The one part of your argument that I think is right is that waste heat that isn't dumped into the atmosphere -- say, water that's used to cool a power plant and then discharged into the ocean -- will have a longer residence time. But, as you and TOP have pointed out in this thread, most anthropogenic waste heat is dissipated directly into the atmosphere. Once it's there, there's no (zero, zilch, nada) difference between it and the heating from GHGs. There isn't some "queue" whereby heat from source A jumps to the head of the line and gets sent off to space while heat from source B sticks around. All the molecules in a given patch of atmosphere share their energy with each other via collisions. You can't say that the energy from waste heat somehow stays in N2 and O2 molecules only and thus avoids getting radiated out to space. That just plain doesn't happen. It's all mixed together indistinguishably.
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  24. Ned #73 "Once it's there, there's no (zero, zilch, nada) difference between it and the heating from GHGs." (Ned refers to energy associated with N2 and O2) AGW contends that CO2 is a portal for transmitting radiative energy between a higher temperature source and non GHGs, or visa versa... (by bringing this up, I am not denying this, just using this to illustrate things)... AGW assumes that the net flow of this portal is in the direct of elevating the temperature of non-GHGs (i.e. arrow is point from surface to CO2 to non-GHGs). When non-GHG are being warmed directly by waste heat sources, this portal is not available (statistically speaking) for getting rid of this heat via CO2 absorption. The only way then for cooling is via convection with cooler surfaces somewhere where it is cooler. Then that energy on the surface or in some colder part of the atmosphere has to somehow by chance not get absorbed by CO2. I think the problem here is in your statement, "Once it's there". The problem is that it shouldnt be there and wouldnt be there if it were allowed to radiate from the source. Just think of a car with huge black, horizontal and insulated heat sink attempting to keep the planet cooler while cooling the engine too.
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  25. RSVP writes: When non-GHG are being warmed directly by waste heat sources, this portal is not available (statistically speaking) for getting rid of this heat via CO2 absorption. The only way then for cooling is via convection with cooler surfaces somewhere where it is cooler. Then that energy on the surface or in some colder part of the atmosphere has to somehow by chance not get absorbed by CO2. Ah, this (the part I have bold-ed) may be the heart of the problem. The portal actually is available equally to heat from absorbed IR or heat from other sources. The atmosphere is well mixed; it's not made up of separate pools of CO2, O2, N2, etc. Imagine that your car engine is somehow able to perfectly discriminate among the atmospheric molecules passing over its radiator. For some reason it refuses to heat CO2 molecules, and saves all its energy for O2 and N2. By the time that air has gone a few feet from your radiator, all that heat has been thoroughly redistributed among its constituent molecules. The "temperature" of the CO2 molecules is exactly the same as the "temperature" of the O2 and N2. Remember, each molecule is interacting with its neighbors around a billion times per second. Does that make sense? It really sounds to me like the root of the problem is that it's natural to think that radiative forcing only warms GHG molecules and waste heat mostly warms non-GHG molecules. (See your first sentence quoted here, "When non-GHG are being warmed ...") In point of fact, in both cases it's the whole atmosphere that's warmed.
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  26. KR #57, I seem to be developing an ability to speak 'rudimentary RSVP'. I believe the one month vs two months bit is referring back to his belief that 'waste heat' accumulates in the climate system while 'greenhouse heat' quickly disperses. It is, of course, complete nonsense. RSVP #71, no one has said (as you claim) that 'waste heat' will cease to exist. I said that it will never become a significant problem unless we are using something like nuclear for most power generation a few hundred years from now. Also, in reference to your points 3a and 3b... plenty of energy reflected back towards the surface by GHGs goes into the oceans and non GHG gases and stays there just as long as waste heat. Water molecules in the ocean do not 'refuse admittance' to 'greenhouse heat' or retain heat that came from a nuclear power plant longer than they do heat that failed to escape the atmosphere due to GHGs. This has been explained to you MANY MANY times. Could you explain what possible reason there could be for believing otherwise? What mechanism exists for individual photons to behave in radically different ways depending upon their history?
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  27. To Ned... You say, "The portal actually is available equally to heat from absorbed IR " I agree, but I did say "statistacally speaking" just for that reason. Try walking into a stadium after the games ends. ----- You say, "Imagine that your car engine is somehow able to perfectly discriminate among the atmospheric molecules passing over its radiator" 370 ppm means 370 parts per million of CO2 versus everything else. That point aside, hot air mixes very fast with surrounding air, but the energy cannot be destroyed and will hangs around. All you have to do is stand by a freeway a few minutes and this is easy to notice. What do you think UHI effect is anyway?
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  28. CBDunkerson #76 Please answer this question... Can GHG radiated heat from the atmosphere cause heating of something that is hot? ... like an asphalt highway midday? or an air conditioners heat exchanger? Hopefully you can see how this is difficult. Along that same idea, the warmer the air (due to whatever) the less effects GHG have. This indicates that this GHG source of global warmging is very relative. I am not saying it is not real. From AGW commenters, one gets the sense that CO2 is spewing power like a hose. Electromagnetics does not work like that.
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  29. CBDunkerson 76 "Water molecules in the ocean do not 'refuse admittance' to 'greenhouse heat' " Overall power normally attenuates when it traverses space. If one square KM of ocean water radiates heat upward, and it hits even a perfect mirror, whatever comes back will be a weakened version of that powerwise. Imagine a business model based on this concept. I send you a $100 (everyday) and you send me back $99. I am going to get richer or poorer?
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  30. Try walking into a stadium after the games ends. Not a useful analogy. If that's how you're envisioning the atmosphere, you're bound to be misled. 370 ppm means 370 parts per million of CO2 versus everything else. Yes, obviously. So? [And we're actually over 390 ppm CO2 now, not 370...] That point aside, hot air mixes very fast with surrounding air, but the energy cannot be destroyed and will hangs around. All you have to do is stand by a freeway a few minutes and this is easy to notice. Again, so? How does this somehow make "air heated by car engine" different from "air heated by absorption of LW infrared"?
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  31. RSVP writes: Please answer this question... Can GHG radiated heat from the atmosphere cause heating of something that is hot? ... like an asphalt highway midday? or an air conditioners heat exchanger? That is getting dangerously close to the Gerlich & Tscheuschner "Second Law of Thermodynamics" nonsense. If you want to get into that, it's discussed elsewhere on this site. (The one-line answer is that warming the atmosphere reduces the rate of cooling of the surface.)
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  32. I have to say that RSVP's comments in this thread seem to be getting increasingly disjointed and incoherent. The "mainstream physics" view of this, as expressed by John Cook's post at the top of this thread, is quite clear and succinct. We know how much waste heat is being produced -- around 0.028 W/m2. We know what the climate forcing is from CO2, CH4, halocarbons, etc. -- around 2.9 W/m2. Since the former is two orders of magnitude smaller than the latter, the former is essentially irrelevant to climate (at the global scale; it's not irrelevant in local areas). Until RSVP can clearly express and preferably quantify an alternative to this -- without relying on inappropriate analogies to traffic jams, stadium crowds, etc., just a clear and simple statement of the proposed physics -- I don't think she/he is going to learn anything. If you cannot express your ideas clearly you cannot test them.
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  33. Oh this is getting really boring RSVP. All you have succeeded in doing is stating what is known about energy and that something 'warm' can not move energy to something 'hot'! Big deal. Great, I now know a hot road or runway (heated by sunlight normally) will dissipate to the cooler surroundings!
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  34. RSVP said "Overall power normally attenuates when it traverses space. If one square KM of ocean water radiates heat upward, and it hits even a perfect mirror, whatever comes back will be a weakened version of that powerwise." erm, I'm no expert in quantum physics and I agree at our bigger scales of observation that is true. But my understanding of physics is that at the quantum level it is impossible to lose anything. eg. the loses you refer to go somewhere. A beam of sunlight disperses over a certain distance, but no photons are lost to the system (universe). It is just that the observer has only collected a smaller number of photons at the particular position. I think there are problems with a lot of engineers and scientists when they start working at a high level and think of things in terms of over arching equations and models, or as one type of energy transport or another. If there are 'losses' at the mirror, those losses go somewhere.
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  35. Ned says... "Not a useful analogy. [referring to stadium] If that's how you're envisioning the atmosphere, you're bound to be misled." If anything, I have had to use this analogy consistent with AGW maintains. Maybe you can describe it better. ----- "We know how much waste heat is being produced -- around 0.028 W/m2. We know what the climate forcing is from CO2, CH4, halocarbons, etc. -- around 2.9 W/m2." The former is like money going into a savings account, the latter a running expense budget. Just because you have more expenses doesnt mean you are getting richer. Its funny how even economist use the term an economy as "over heating". But without using analogies. AGW climate models themselves rely on the term "Radiative" budget. Most of waste heat does not involve radiation, except in the terms that I have done in order to generously accomodate AGW theory.
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  36. Actually adding to my previous post. There are only 'losses' in the beam from the mirror described by RSVP because of imperfections in the mirror, or the mirror is curved (convex) or because there is something between the mirror and the ocean (an atmosphere), or ultimately the photons are bent by gravity. eg. there is only attenuation because of imperfections and other issues. It is attenuated by intervening matter. Assuming the mirror was smaller than the ocean, then even if the 'signal' was attenuated, the energy would be returned towards the ocean and it remains in the system.
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  37. RSVP: The former is like money going into a savings account, the latter a running expense budget. Nonsense. They're both sources of income going into the same account, just that one is your paycheck and the other is the spare change you pick up on the street. There are not two separate atmospheric heat reservoirs. AGW climate models themselves rely on the term "Radiative" budget. So? Why is that significant? Most of waste heat does not involve radiation, except in the terms that I have done in order to generously accomodate AGW theory. We have 0.028 W/m2 of heat entering the atmosphere from anthropogenic sources ("waste heat"). We have 2.9 W/m2 of heat entering the atmosphere from absorption of IR. Both of those packets of heat are now in the atmosphere. Please explain the difference between what happens to packet A and what happens to packet B.
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  38. But without using analogies. AGW climate models themselves rely on the term "Radiative" budget. Most of waste heat does not involve radiation, except in the terms that I have done in order to generously accomodate AGW theory. The radiative budget refers to energy entering and leaving the planet. It isn't a case of 'relying' on it. There is only one mechanism for energy entering and leaving the earth. At some point, energy that isn't in the form of radiation has to be converted to it. The alternative is to lose atmosphere, but that is a bit short term.
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  39. The Ville #84 The reason less energy comes back over the same area (assuming an infinite sized mirror and no losses) is that it disperses. So to find it all you would then have to examine a larger area depending on how far away the mirror. If the entire globe was completely water, GHG would simply dull the energy emission profile such that instead of more radiation from the equator vs poles, it would even out some. This however does not support the idea that GHG cause overall warming.
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  40. Ned #87 Careful. You dont have to declare the money you find on the street. ;)
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  41. Ned #87 "Both of those packets of heat are now in the atmosphere." Are they? We know the waste heat is, that is for sure. What about the virtual heat due to GHGs??? Where exactly is that? Photon radiates off a lizard's back. Hits a CO2 molecule on the way to Pluto (which is now no longer a planet. Oops!). The CO2 writhes, bounching one million times per second and kinetically energizes its nearby N2 neighbors. If it werent for man, this CO2 molecule would not have been there and Pluto would have received the lizard's warmth. However man has been polluting for hundreds of years and the chance is now higher that Pluto will have to wait. A millionth of a second later, a different CO2 molecule comes to the rescue. It picks up this energy. This time the photon shoots upward. Instead of Pluto, it ends up in an uncatalogged black hole. Now, for I billionth of a second, AGW supporters are vindicated. If you call this the same thing, I think then we do agree.
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  42. 1. It is obvious that this is not waste heat caused the current warming, but largely responsible for its “unprecedented”. I had a "reservation" to the Dutch (de Laat), not citing this work: Modeling the impacts of anthropogenic heating on the urban climate of Philadelphia: a comparison of implementations in two PBL schemes. Fan and Sailor, 2005: “Results from a case study series of simulations for Philadelphia suggest that anthropogenic heating plays an important role in the formation of the urban heat island, particularly during the night and winter. Control simulations (without anthropogenic heating) CONSISTENTLY UNDERESTIMATED urban air temperatures and the observed urban heat island effect. Simulations for winter suggest that anthropogenic heating contributes 2–3 °C to the nighttime heat island. In addition, anthropogenic heating is also found to have impacts on the nocturnal PBL stability and PBL structure during the morning transition. The choice of PBL scheme affects the magnitude of these modeled impacts.” 2. The waste heat is present in the atmosphere much longer than it seems to us (A) and present a significant - a long way there is finally somewhere “scatter” (B). A. The waste heat, like solar energy, is difficult to escape the UHI (where it produces the most): „When natural land cover, such as parks, is decreased and replaced by buildings, the cooling process through evaporation is reduced. As well, when rural areas that surround cities are urbanized, the atmospheric circulation systems that carry cooler air to city centres are restricted. These atmospheric cooling systems are normally generated by the temperature differences which exist between cool rural and warm urban environments. Furthermore, the arrangement and size of buildings along narrow streets forms a so-called URBAN CANYON that inhibits the release of the reflected radiation from urban surfaces back to space. This radiation becomes absorbed by the building walls.” (based on: Urban Heat Island Mitigation in Canadian Communities., Forkes, 2009 - I recommend drawing showing URBAN CANYON as a store of energy, of course + NBL, smog, air pollution, etc.). B. The waste heat is obviously “Thermal Plumes” (Rail, 2007, Urban Thermal Plume; Rail, 2010, Anticarbonism: exposing the carbon dioxide myth.) ... here I will give “excerpts” to Wikipedia: “In 2007, Anthony Rail, postulated that London's urban thermal plume, say, will generally have a detectable impact, and at times have a significant impact on the macrometeorology of Northern Europe, and may play as significant a role in Climate change as the anthropogenic augmentation of atmospheric CO 2 . A thermal plume from a large urban area is much more complex than that from, say, a large chimney stack. It is better regarded as a concatenation of several separate thermal plumes, their turbulence increased by the presence of cool-spots such as parks and, especially, lakes within the urban environment. A geographical area such as the British Isles has a thousand urban areas and many industrial sites, all of which will at times produce thermal plumes of different magnitudes. Their effect on the wider meteorology will be cumulative, through interaction between plumes, interaction between local wind variations as affected by plumes, and the influence of other topographical effects, not least of which are the cool areas of estuaries, lakes and man-made reservoirs. Absolute modelling of these collective effects is in a sense impossible, in that we cannot know the dynamics of the native geometeorological system in, for example, the British Isles. We can't model the innate wind patterns, because the innate wind patterns no longer exist. We can't 'turn off' all the anthropogenic thermal influences to rediscover the geometeorological systems before industrialization, urbanization, and large-scale water management; and then turn man's influence back on to observe the differences.[...]” “While recognising that the steady lessening of vertical motion towards the edges of urban thermal plumes will have an ameliorating effect, Rail proposed that such urban thermal plumes play a critical part in producing the changes in ambient wind direction over the ARCTIC and have had a direct impact on Arctic shrink. The impact of urban thermal plumes will vary depending on a large variety of factors including the diameter and temperature gradient of the Urban heat island , the latitude, the thermal stability of the stratiform, the synoptic wind , &c. Thus, for example, urban thermal plumes will have far greater impact at higher latitudes (above 40°N and above 40°S), where the Earth-atmosphere system undergoes net cooling by radiation.” Remember that CO2 can more or less constant throughout the RF of the Earth, causing waste heat (and a small area) differences over 100W (...). Thus, in a waste heat - 1 W heat - many times more (through feedback) efficient than the 1 W in the CO2 from its conjugates by positive feedback (a mailing - we might add) ...
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  43. RSVP writes: Photon radiates off a lizard's back. Hits a CO2 molecule on the way to Pluto (which is now no longer a planet. Oops!). The CO2 writhes, bounching one million times per second and kinetically energizes its nearby N2 neighbors. If it werent for man, this CO2 molecule would not have been there and Pluto would have received the lizard's warmth. However man has been polluting for hundreds of years and the chance is now higher that Pluto will have to wait. This is exactly right. Everything up to here is fine. And the key point is that there's no difference between (a) an N2 molecule warmed by collision with a CO2 molecule that once absorbed an IR photon, and (b) an N2 molecule warmed by collision with another N2 molecule that once was heated by collision with an engine radiator. With that established, let's return to RSVP's entertaining story of the lizard, the atmosphere, and the former planet Pluto: A millionth of a second later, a different CO2 molecule comes to the rescue. It picks up this energy. This time the photon shoots upward. Instead of Pluto, it ends up in an uncatalogged black hole. This is OK too. But the exact same thing happens with the energy from waste heat! The N2 molecules share their energy with CO2 molecules, and the process proceeds exactly as you described. Thank you for taking the time to organize this into a series of clear physical steps. It seems like we might be starting to get somewhere.
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  44. Arkadiusz - you have some excellent points about the localization of urban heat islands (UHI). I do find it interesting that land use changes (albedo changes, microscale wind changes, etc.) are as large or larger effects than energy usage. To some extent these complex UHI's could be considered to be stationary thunderstorms - multiple convection cells of heat input. However, as with real thunderstorms, they occupy a very small area! There may be 100 W/m^2 in some urban areas, but the global average is only 0.028 W/m^2. Much as thunderstorms, which are very powerful redistributors of latent heat, occupy a very small percentage of the atmosphere at any one time. I would readily believe that UHI's produce local effects on weather. However, the land usage change and the anthropogenic heat flux (AHF) of energy usage won't have a major effect on global temperatures, as they are two orders of magnitude smaller than GHG entrapment. We must always be careful not to mistake impressive local events for more dominant (but quieter) global events which are much larger. Size does matter!
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  45. Ned #82 and many other threads: Sorry Ned, the Earth system is not accumulating 2.9W/sq.m of heat flux. The purported figure is 0.9W/sq.m. The critical measurement is the TOA imbalance which nets all the heating and cooling forcings. Ref Fig 2.4 of AR4 which gives a total net anthropogenic forcing of +1.6W/sq.m. To this number is then added the climate responses which mainly consist of radiative cooling (from a raised Earth temperature of 0.75 degC as per S-B) of about -2.8W/sq.m and WV and Ice Albedo Feedback of about +2.1 W/sq.m. (Ref Dr Trenberth Fig 4 'Tracking the Earth's global energy) The sum is then +1.6 -2.8 +2.1 = +0.9W/sq.m It is misleading to claim that +2.9W/sq.m is 'entering the atmosphere' from absorption of IR when all the heating and cooling forcings are acting in concert. S-B is emitting IR, Aerosols and clouds are reflecting incoming Solar heat, while CO2GHG are supposedly trapping Solar heat at lower levels (the mechanism may be slowing down the transfer rather than 'trapping' heat) which tends to raise the equilibrium temperature as the analogy of a better insulator increases the T1-T2 temperature difference for a given heat flux transferred. What is certain is that CO2GHG forcing (currently at about 1.6W/sq.m) is logarithmic with CO2 concentration, and S-B radiative cooling is exponential (proportional to T^4). Where these forcings cross is where the forcing imbalance is zeroed and the new equilibrium temperature approached. The CO2GHG theory hangs on the interaction of WV and CO2 in the atmosphere and what will be the surface temperature rise for a unit rise in the IR emitting temperature of the earth as seen from space. For the first law to be satisfied, most of heat flux 'imbalance' of 0.9W/sq.m should show up in the oceans due to the tiny relative storage capacity of the land and atmosphere. OHC is proving most elusive to measure.
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  46. Ken, I addressed that point when you made it the first time, on the first page of this thread. If you want to look at the net forcing that the climate is actually experiencing, then yes, you need to add up all the positives and negatives. If you want to answer the question "is forcing A (waste heat) larger than forcing B (greenhouse gases)?" then you need to ... look at the magnitudes of the individual forcings A & B. That's what this thread is about. It is a good thing that we don't have a net TOA radiative imbalance of 2.9 W/m2. The estimated actual TOA imbalance of 0.85 W/m2 corresponds to a climate sensitivity of 3.1C per doubling, basically the IPCC consensus value. That is bad enough, IMHO.
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  47. RSVP, Maybe I'm wrong, but it seem that you and Ken are trying to minimize or even dismiss the role of GHG forcing and are suggesting that "waste heat" is responsible for the observed warming. Sorry if you have already addressed this, but given that you believe that the contribution of waste heat to the earth's energy budget is detectable, how much of the observed warming (of the biosphere) over the last century do you attribute to "waste heat". Please explain how you arrive at that number and also specify whether or not you take into account the fact that GHGs were released in the production of said "waste heat"?
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  48. RSVP said: "The reason less energy comes back over the same area (assuming an infinite sized mirror and no losses) is that it disperses." A mirror with no losses would be perfect so there would be no dispersal of photons. eg. a perfect mirror would 'knock' every photon back and there would be no dispersal of photons or weakening of the 'signal'. But in any case if you have a mirror enveloping the planet (which is what you are suggesting the analogy was), it doesn't matter if there are 'optical' faults in the mirror or dispersal, the energy reflected will be retained whether there is 'dispersal' or not. In fact because of imperfections and 'dispersal' you would actually get 'hot spots' and 'cool spots'. I would really like to know your profession RSVP, are you an engineer?
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  49. Dear contenders. Their views suggest that the land is or was in perfect thermal equilibrium. (John R # 70) Our climate is a function of many variables such as solar flux, the evaporation of water, the dissipation by convection, the transfer of energy, the rain, etcetera, Do all these variables are perfectly in balance? Our climate handles 1370 watts per square meter and an error of 1% is already 13.7 W/m2 and making negligible the 0.028 W/m2 discussed here. I want to warn their friends that this error actually exists in our system. The soil is being impermeabilisad by ammonium created in the soil by the decomposition of organic matter. (A natural process). Due to this impermeabilisation not have enough water to keep the indices of evaporation. This problem is to be resolved. But while this have not a solution, we can spread sea water in the desert of the Sahara. With an evaporation potential of 10 liters per day per square meter will be converted to 25.08 MJ day of latent heat and will be redistributed to higher latitudes. This equates to 290.27 W/m2 of desert. Watts is Watts who is not Joule but Joule per second.
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  50. Our climate handles 1370 watts per square meter Divide by 4 to distribute across the globe. Multiply by 0.7 to account for albedo. That gives you the actual solar input (240 W/m2). It varies by less than 1% peak-to-trough of the solar cycle. And of course the solar cycle is a cycle. we can spread sea water in the desert of the Sahara. With an evaporation potential of 10 liters per day per square meter will be converted to 25.08 MJ day of latent heat and will be redistributed to higher latitudes. That would cool the Sahara, yes. What happens to the latent heat when the resulting water vapor condenses and precipitates somewhere else? Again, there's a reason it's called the hydrologic cycle.
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