Atmospheric Heat Engine

In the interests of unfanning (not actually a word, it would seem) the flames, or not fanning them any further, I thought I would write about what seems to be an interesting paper brought to my attention by William Connolley. It’s by Laliberte et al. (2015) called Constrained work output of the moist atmospheric heat engine in a warming climate. It’s also covered in a recent Smithsonian article.

To be quite honest, I’m not sure I quite understand it, so I’m hoping some of my more informed (than me, that is) commenters can elaborate. As I understand it, the idea is that one can think of the atmosphere as some kind of heat engine, with energy transported from the surface, through the atmosphere where it can do some work, and then to the upper atmosphere where it is radiated into space. In this scenario, one ignores the energy lost directly to space from the surface via radiation, and need only consider the energy transported via convection and evaporation. So, one can write that the work done per unit time, W, is the difference between the total amount of energy avaliable per unit time \dot{Q}_{total} and the energy associated with evaporation and then precipitation (water cycle – \dot{Q}_{moist}). In other words,

W = \dot{Q}_{total} - \dot{Q}_{moist}.

Figure 4 from Laliberte et al. (2015)

Figure 4 from Laliberte et al. (2015)

What they’ve done in this paper is then use climate models to consider how these quantities will change as we warm. The basic result seems to be that the increase in the water cycle, \dot{Q_{moist}}, exceeds the increase in the total available energy, \dot{Q_{total}}, and hence the amount of energy available to do work and to drive actual atmospheric circulation goes down. The conclusion they draw is

As the climate warms, the system may be unable to increase its total entropy production enough to offset the moistening inefficiencies associated with phase transitions. This suggests that in a future climate, the global atmospheric circulation might comprise highly energetic storms due to explosive latent heat release, but in such a case, the constraint on work output identified here will result in fewer numbers of such events. Earth’s atmospheric circulation thus suffers from the “water in gas problem” observed in simulations of tropical convection, where its ability to produce work is constrained by the need to convert liquid water into water vapor and back again to tap its fuel.

Therefore, there will be less energy available to do work, with the consequences that there will be fewer storms, but that they could be highly energetic when they do happen.

Carnot_heat_engine_2.svgAlthough I could embarrass myself by doing this, I thought I might try and understand why this could be the case. In a basic Carnot heat engine, you take energy Q_H from a reservoir at temperature T_H, you then do an amount of work W, and then transfer the remaining energy, Q_C, to a reservoir at temperature T_C. The maximum efficiency \eta is then given by

\eta = \dfrac{W}{Q_H} = 1 - \dfrac{T_C}{T_H}.

One of the feedbacks that we expect as we warm is lapse rate feedback. What happens here is that water vapour evaporates from the surface and then condenses in the atmosphere, releasing heat. However, this doesn’t happen uniformly throughout the vertical atmosphere, but preferentially happens at higher altitudes, rather than lower. Consequently, the upper atmosphere warms more than the lower atmosphere/surface, changing the lapse rate (vertical temperature gradient). Therefore, if we think of this as a heat engine, the cool reservoir (upper atmosphere) is warming more than the hot reservoir (surface/lower atmosphere) and therefore the maximum efficiency reduces.

Now, I don’t know if my basic explanation above is correct, or if my understanding of this is correct at all. So, if anyone understands this better than I do (which isn’t hard) feel free to explain it in the comments. This also might be an interesting topic, given the small furore about the recent snowstorm in the NE USA.

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174 Responses to Atmospheric Heat Engine

  1. -1=e^ipi says:

    Since many climate phenomena are basically giant heat engines, if you reduce the polar-equatorial heat gradient or the surface-tropopause heat gradient then one would expect that these climate phenomena get weaker/less frequent.

    Of course this basic physics is inconvenient for the climate alarmists who often claim that global warming will cause the Earth’s climate to become more extreme in every since way.

  2. -1=e^ipi.
    Yes, good point. Changes to the polar-equatorial gradient could also influence the maximum efficiency and, hence, the amount of energy available to do actual work.

  3. jsam says:

    As soon as I read “alarmist” in a comment I feel for my wallet. Someone is trying to fleece me.

  4. jsam,
    Blast, I didn’t read the latter half of -1=e^ipi’s comment. Seems his/her basic physics is pretty good, but otherwise a bog standard conspiracy theorist/strawmanner.

  5. -1=e^ipi, I am a climate scientist or what your ilk calls “climate alarmist”. Thus I am afraid that your statement is not entirely correct as you can see from my comment here from 2013. But it is nice that some ideas of scientists are picked up by the mitigation sceptics, that can lift the level of the discussion a little.

    Victor Venema says:
    October 5, 2013 at 7:58 pm

    I wouldn’t say that increases in extreme weather are guaranteed. In as much as the mean temperature and precipitation increases, you would expect that also the extremes increase. However, also the variability around the mean is important for the probability of getting an extreme event.

    Many types of variability are expected or observed to decrease. The temperature difference between the equator and the poles. The temperature difference between summer and winter (stronger trends for winter temperatures), and between night and day (stronger increases in daily minimum temperature). Also the year to year variability in the yearly mean temperature may get smaller. (Other types of variability do increase.)

    In the end, climatology expects that heat waves will get worse and that strong precipitation will increase stronger as mean precipitation. However, that is not fully trivial, you do have to study for every phenomenon what will happen. Studies on extremes are still in their early stages. A lot can still happen to our understanding a changes in extreme weather.

    If climate ostriches had one a little understanding of science, they would not make ludicrous claims about CO2 not being a greenhouse gas, they would not claim that the mean temperature is not increasing or only half, they would not claim that homogenization is just smoothing and all that other much too obvious nonsense that hurts their credibility, they would talk about all the uncertainties in projections for extreme weather and thus uncertainties in the societal costs of climate change.

    This naturally assumes that climate ostriches would keep their strange slogan that uncertainty means that nothing will happen.

  6. Andrew Dodds says:

    -1=e^ipi –

    The problem is, some of what we call extreme events are things like atmospheric blocking patterns – persistent high pressure, a constant stream of storms, that kind of thing – that go on for great lengths of time. So if we are doing less work, then that sort of event would be expected to become more common.

    This is speculative stuff, admittedly, and it would help to have a few spare planets to experiment on. Therein lies the real problem.. (unless someone can work out a way to deduce weather from paleo records)

  7. -1=e^ipi says:

    “to become more extreme in every since way.”

    Sorry, mean to say single not since. I might need to see a neurologist about these spelling mistakes, it might be due to my brain injury. :/

    “Yes, good point. Changes to the polar-equatorial gradient could also influence the maximum efficiency and, hence, the amount of energy available to do actual work.”

    I think a good example of a phenomena that will be greatly affected by this is tornadoes in Tornado Alley. They should greatly decrease due to global warming.

    “but otherwise a bog standard conspiracy theorist/strawmanner.”

    So does using the word alarmist mean I am a conspiracy theorist/strawmanner? Isn’t that jumping to conclusions? Isn’t it possible to think that the positions of both Christopher Monckton and David Suzuki are nonsense?

    @ Victor Venema –
    As soon as you define extreme weather as ‘deviation from the historic mean by a few sigma’ then the definition you use and the definition the public uses are different. If you asked the public what extreme weather means, they would say things like floods, droughts, blizzards, hurricanes, tornadoes etc. Most people would probably agree that -30 C is more extreme than -5 C. But if is July in Winnipeg and it is -5C, that is ‘extreme weather’ where as -30C is normal. Furthermore, if you define extreme weather in this way, then any change (global warming, global cooling) to the Earth’s climate will increase ‘extreme weather’.

  8. -1=e^ipi says:

    Sorry, I meant January in Winnipeg, not July.

  9. -1=e^ipi,

    So does using the word alarmist mean I am a conspiracy theorist/strawmanner? Isn’t that jumping to conclusions? Isn’t it possible to think that the positions of both Christopher Monckton and David Suzuki are nonsense?

    Possibly, it was mainly a response to your “physics is inconvenient for the climate alarmists” rhetoric. In my experience, many who accuse others of alarmism haven’t actually read what is supposedly alarmist in the first place.

  10. Brandon Gates says:

    ATTP, no help from me here with the maths but more of a peanut-gallery type observation that …

    Therefore, there will be less energy available to do work, with the consequences that there will be fewer storms, but that they could be highly energetic when they do happen.

    … is getting mangled beyond all recognition by the usual suspects, so I appreciate you soliciting comment.

  11. -1=e^ipi says:

    “The problem is, some of what we call extreme events are things like atmospheric blocking patterns – persistent high pressure, a constant stream of storms, that kind of thing – that go on for great lengths of time.”

    Are you referring to the slowing of the Northern Polar Jetstream due to the decrease in the temperature gradient between the Polar and Ferrel cells? If so, an increase in global temperatures by ~3C will increase the frequency of the Jetstream getting stuck by something like ~28% (based on the calculations I did nearly a year ago).

  12. -1=e^ipi says:

    “to your “physics is inconvenient for the climate alarmists” rhetoric. In my experience, many who accuse others”

    More accurately I said, ‘this basic physics’ and I didn’t accuse anyone specifically. If you want me to give you some names of people I think this is inconvenient for, I would say Al Gore and David Suzuki.

  13. Brandon Gates says:

    -1=e^ipi,

    Furthermore, if you define extreme weather in this way, then any change (global warming, global cooling) to the Earth’s climate will increase ‘extreme weather’.

    “Reality is that which, when you stop believing in it, doesn’t go away.” ~Philip K. Dick

    Or in other words, the train is still going to hit you even if you shut your eyes.

  14. -1=e^ipi,

    More accurately I said, ‘this basic physics’ and I didn’t accuse anyone specifically. If you want me to give you some names of people I think this is inconvenient for, I would say Al Gore and David Suzuki.

    Yes, I know you didn’t. My point was a general observation. No, I’m not interested in a “but Al Gore” or “but David Suzuki” discussion. I don’t even specifically object to you using “alarmist”, I just think that if you want to have reasonable discussions here it would probably be better if you didn’t, or if you did so carefully.

  15. Willard says:

    > I didn’t accuse anyone specifically.

    The good old “if the shoe (hat, …) fits” gambit.

    Please don’t mix equations with such gambits, Minus One.

  16. OPatrick says:

    -1=e^ipi’s us of ‘alarmist’ is a flag, but what seems offensive to me is not the term iteself but the accusation that there are a significant number of people who claim that global warming is going to make the Earth’s climate more extreme in every single way. In my view a reasonable discussion would be aided much more by either withdrawing or carefully justifying that accusation, and the assertion that this is ‘inconvenient’ for anyone, rather than by avoiding the use of the word alarmist.

  17. Lucifer says:

    This is an important phenomenon to understand.
    We should note that the predicted result, increased warming aloft, has not occurred,
    as I depict here in a comparison of the GISS model compared to observations since 1979:

  18. Lucifer,
    Maybe try treading this. Also, bear in mind that the tropospheric hot spot is not an AGW specific signature.

  19. -1=e^ipi says:

    @ Brandon Gates –

    All I’m saying is defining ‘extreme weather’ as a certain variation from the historic mean is misleading/flawed. If pre-industrial temperatures were 3 degrees warmer and then the Earth cooled by 3 degrees, that would lead to ‘more extreme weather’. And if pre-industrial temperatures were not 3 degrees warmer and then the Earth warmed by 3 degrees, that would lead to ‘more extreme weather’. So if you go from climate A to B, that leads to more extreme weather. And if you go from climate B to A, that leads to more extreme weather. What if you go from A to B to A, does that mean you have more extreme weather even though you have the exact same climate?

    Basically, any useful definition that tries to quantify ‘extreme weather’ needs to have the transitive property.

    Otherwise, the definition of extreme weather about as useful as economists/sociologists that define poverty to be a certain fraction of medium income (which violates the pareto principle).

  20. -1=e^ipi says:

    “I just think that if you want to have reasonable discussions here it would probably be better if you didn’t, or if you did so carefully.”

    Maybe you are right. Everyone seems so defensive here. Example: I made 3 estimates in a row of the ESS in the ‘models don’t over estimate warming’ comments and this made BBD conclude that I “very clear intention of confecting low sensitivity estimates by any means possible.”.

  21. -1=e^ipi says:

    “but the accusation that there are a significant number of people who claim that global warming is going to make the Earth’s climate more extreme in every single way.”

    But there are. Just like there a significant number of people who think that global warming is some sort of socialist conspiracy, a significant number of people that don’t believe in evolution, and a significant number of people that think vaccines cause autism.

    If you want me to back up my claim with examples I can. But I don’t think it is helpful to deny that large segments of the population misunderstand the scientific implications of climate change, especially since many of these people are politicians and policy makers.

    “this is ‘inconvenient’ for anyone, rather than by avoiding the use of the word alarmist.”

    But it is inconvenient for some people. For some people, climate alarmism is basically a religion. Us humans have sinned against Mother Gaia (via materialism and fossil fuel emissions) and now we will be punished (via global warming) unless we repent (via mitigation policies). People will dogmatically try to justify their belief however they can, so anything that goes against the ‘global warming will be the end of the world’ narrative is inconvenient.

  22. -1=e^ipi,

    But there are. Just like there a significant number of people who think that global warming is some sort of socialist conspiracy, a significant number of people that don’t believe in evolution, and a significant number of people that think vaccines cause autism.

    If you want me to back up my claim with examples I can.

    No, not really.

  23. BBD says:

    But it is inconvenient for some people.

    Conflating ‘environmentalism’ with physical climatology is an old and threadbare rhetoric.

  24. -1=e^ipi says:

    @ ATTP –

    Your last post is a bit ambiguous to me. Do you mean not really you don’t want me to back up my claim, not really that you don’t agree with my claims, or not really that you don’t think the comparison is appropriate?

    @ BBD –

    Are you suggesting that I am doing that?

  25. Joseph says:

    climate alarmism is basically a religion

    Isn’t the simplest explanation that these people trust the science and think we need to do something about it? I mean why does that have to be some religious experience? Sure there probably are people who believe in some sort of Gaia just like there are people who believe that Bigfoot is out there and are looking for him actively.

  26. -1=e^ipi,

    Your last post is a bit ambiguous to me. Do you mean not rally you don’t want me to back up my claim, not really that you don’t agree with my claims, or not really that you don’t think the comparison is appropriate?

    What I mean is I don’t want to have a discussion where you try to find examples of people who’ve been alarmist. I don’t really care. BBD highights the reason. Conflating environmentalists who might ver-hype something like climate science has no actual bearing on physical climatology.

  27. Michael 2 says:

    ATTP says “Therefore, if we think of this as a heat engine, the cool reservoir (upper atmosphere) is warming more than the hot reservoir (surface/lower atmosphere) and therefore the maximum efficiency reduces.”

    Yes, that is the way I see it. The mechanism is easily visible on a hot summer day by the “lumpy” nature of the tops of clouds — each is a small heat plume pushing heat upwards but each is competing with its neighbors, none is strong enough to dominate and push upward to 15.000 meters or higher — except occasionally, and then you’ll probably have a storm.

    At the surface, warming is constrained by evaporation of water; it cannot become much warmer, and yet there’s a lot of “heat energy” available. So, lots of evaporation, lots of latent heat, not much of a vertical gradient (lapse rate). The latent heat won’t be released until high in the air column, and then usually gradually — a LITTLE of the vapor will condense, releasing heat and reducing the lapse rate (as you have proposed) even further.

  28. Michael 2 says:

    Joseph says: “Isn’t the simplest explanation that these people trust the science and think we need to do something about it? I mean why does that have to be some religious experience?”

    It’s just a definition. Trusting an authority and then taking action based on your belief is a reasonable definition of “religion”, some versions of which have as a supreme being just a human of some virtue (Buddha or Confucius for instance).

    More to the point, when “doing something about it” becomes imposing that action on non-believers, then it resembles both Christianity and Islam.

    Note also the parallel — the actual scientists doing climate research are seldom the public authorities. Al Gore, for instance, has a degree in political science. Pachauri is an engineer. Same in religion — many people (me included) have some pretty solid religious experiences and yet are not, and never will be, religious authorities. I have so little charisma I probably could not persuade people to leave a burning building.

  29. Lucifer says:


    This is an important phenomenon to understand.

    Why is it that these puzzled commenters have names such as Lucifer, Shub Niggurath, CatWeazle666, Genghis, etc ? Are they using alarmist tactics by choosing these names ?

    #WHUT’s up with that?

  30. verytallguy says:

    -1=e^ipi (and everyone responding ),

    An interesting post but 27 comments later we’re still discussing alarmism after you pitched in at the top, which IMHO is a bit dull and detracts from the topic. 

    Could I suggest a pause for breath and then some on topic posts?  It’s a really interesting topic.

  31. vtg,

    Could I suggest a pause for breath and then some on topic posts? It’s a really interesting topic.

    Yes, the goal of this post was indeed an attempt to get away from discussing ClimateballTM and onto something a bit more substantive.

  32. Steven Mosher says:

    Of course this basic physics is inconvenient for the climate alarmists who often claim that global warming will cause the Earth’s climate to become more extreme in every since way.

    Of course this basic physics is inconvenient for the argument that global warming will cause the Earth’s climate to become more extreme in every single way.

    See how easy.

  33. -1=e^ipi says:

    @ Joseph –

    “Isn’t the simplest explanation that these people trust the science and think we need to do something about it?”

    ‘Trust the science’ is a very ambiguous statement. People should follow the scientific method, but I think what you mean is closer to ‘people should blindly believe what authority figures in science tell them’. This can get very dangerous and appeal to authority is not part of the scientific method. Rather the scientific method involves questioning authority and skepticism.

    As for ‘doing something about it’, usually the action (for example, mitigation policies) that people want to take has not been properly justified and sometimes the best action can be no action. The scientific method does not tell people what to do, and if you want to properly justify mitigation policies (for example) then a cost-benefit analysis needs to be done. Yet too often I see people trying to justify mitigation policies using a bizarre variant of Pascal’s Wager or by making a significant amount of unjustified assumptions such as any change to the Earth’s climate is necessarily bad.

    “I mean why does that have to be some religious experience?”

    It doesn’t have to be. But people make it into a religion.

  34. Willard says:

    > But people make it into a religion.

    Don’t be so defensive.

  35. -1=e^ipi.

    As for ‘doing something about it’, usually the action (for example, mitigation policies) that people want to take has not been properly justified and sometimes the best action can be no action. The scientific method does not tell people what to do, and if you want to properly justify mitigation policies (for example) then a cost-benefit analysis needs to be done.

    Well, yes, but you also need to do this with the best evidence available which means not ruling out, for example, that climate sensitivity could exceed 3k.

    Yet too often I see people trying to justify mitigation policies using a bizarre variant of Pascal’s Wager or by making a significant amount of unjustified assumptions such as any change to the Earth’s climate is necessarily bad.

    Well, I see many justifying doing nothing by arguing that climate sensitivity will probably be low. It might be low, but it probably won’t be. Also, I don’t think people are simplistically saying that any change is bad. The more sophisticated argument is that we’re changing our climate faster than at any time in human history and that the range of parameter space over which these changes could be bad is probably significantly greater than the range over which it could, by chance, be good. Bear in mind that we can’t survive if the wet bulb temperature exceeds 35oC.

  36. Steven,

    Of course this basic physics is inconvenient for the argument that global warming will cause the Earth’s climate to become more extreme in every single way.

    And changing the words doesn’t make it “not a strawman” 🙂

  37. verytallguy says:

    So, first to confess that I really don’t understand this.

    As I understand it, the “heat engine ” works thus:

    Moist air rising cools.  The cooling rate falls as latent heat from water vapour condenses.  This increases buoyancy of the air, which continues to rise until the tropopause is reached.  The air can now cool radiatively and does so until it sinks. Thus circulation is driven.

    What I don’t understand is why this would be weaker in a warmer world (or if it’s right at all to be honest) The temperature difference surface to tropopause is higher.  The latent Hest release is higher due to moister air at the surface.   So what’s the mechanism to weaken the heat engine? 

    A good explanation of hurricanes as heat engines here:

    http://www.ems.psu.edu/~nese/ch11sec3.htm 

  38. Willard says:

    > alarmism after you pitched in at the top

    Not at all, Very Tall, for “but religion” puts it to eleven:

    Even then, we can push it to infinity.

    You’ll never guess how.

  39. Joshua says:

    Much simpler

    Of course this basic physics shows that global warming will not cause the Earth’s climate to become more extreme in every single way.

    Implying that the shoe fits has nothing to do with the science..

  40. guthrie says:

    Of course we could go off on a tangent speculating about the names people use. I happen to use my own, but some people like ‘lucifer’ because it translates as light bringer, thus they bring the light to poor benighted folk. Shub niggurath is a reference to the Cthulhu mythos, and if I recall correctly is a bit goat like. Or was that his 9000 children? Anyway, since it’s from a work of fiction it has less widely known connotations as lucifer.

  41. MikeH says:

    You are being trolled by -1.

    The idea that “fewer but more intense” is a good news story is ridiculous. It will take the Phillipines generations to recover from Typhoon Haiyan. The richest country in the world is recovering from the effects of Superstorm Sandy. And we face more intense storms than that?

    If you had to choose, surely you would select the exact opposite – more storms but less intense since “less intense” is what our defences are currently built to cope with.

    As I recall, in respect of tropical cyclones, the idea of fewer but more intense has been a part of the IPCC reports for a while although that has been challenged more recently.

    e.g. http://www.pnas.org/content/110/30/12219.abstract

  42. -1=e^ipi says:

    “What I mean is I don’t want to have a discussion where you try to find examples of people who’ve been alarmist. I don’t really care.”

    Sorry, my intention was never to derail the discussion. I never expected to so many people acting so defensively to the use of the words ‘climate alarmists’.

    This topic is very interesting and I’ve mentioned this issue in the past to c̶l̶i̶m̶a̶t̶e̶ ̶a̶l̶a̶r̶m̶i̶s̶t̶s̶ ‘people that disagree with me’. Decreasing the polar-equatorial heat gradient should reduce tornadoes in places like Tornado Alley and Tornado Alley should move upwards. So you get more frequent Tornadoes in Southern Canada, but more frequent Tornadoes in Tornado Alley. The net result should be less frequent and less severe Tornadoes.

    The effect on Hurricanes is also interesting. Since hurricanes are giant heat-engines that transfer heat from the surface to the tropopause, one would expect that a reduction of this heat gradient reduces the frequency and intensity of hurricanes. There seems to be confusion in the public that because hurricanes happen more frequently in equatorial places that warmer temperatures = more hurricanes. Hurricanes do occur in polar regions, they are called polar lows. As for mid-latitudes, the fact that winds go from west to east in the Ferrel cells makes it difficult for hurricanes to form. Didn’t the IPCC change its positive from ‘the intensity and frequency of hurricanes is expected to increase’ to ‘climate models show that the intensity and frequency of hurricanes will either stay the same or decrease’?

    Though what is really interesting is the effects on the jetstreams. The reduction in the polar-equatorial temperature gradient will arguably make the climate more mild. However, this reduces the speed of the jetstreams (particularly, the Northern Polar Jetstream is most relevant) which increases the jetstream’s amplitude, increases the jetstream’s wavelength, increases the frequency of the jetstream getting ‘stuck’, reduces the group velocity of the jetstream, and has other effects. I wrote why this is exactly a few months ago and how one can easily derive this relationship as well as how one can get the approximate expected changes due to climate change, but unfortunately I used those two words that you guys seem to dislike, so it is probably a bad idea to provide a link to that explanation.

  43. -1=e^ipi says:

    @ ATTP –

    “Well, yes, but you also need to do this with the best evidence available which means not ruling out, for example, that climate sensitivity could exceed 3k.”

    So just take into account the uncertainty when doing a cost-benefit analysis and go with the policy that has the highest net-benefit.

    “Also, I don’t think people are simplistically saying that any change is bad.”

    Well I see that all the time (both implicitly and explicitly). I’ve even had a friends who stopped speaking to me when I dared to question ‘how do we know that global warming is actually bad’ one time as they were so surprised that someone would even ask the question. The idea that the Earth’s climate was somehow optimal in pre-industrial times is an unjustified assumption that many are making so they can circumvent the burden of proof required to justify mitigation policies.

    “The more sophisticated argument is that we’re changing our climate faster than at any time in human history”

    That by itself is no where near sufficient to justify mitigation policy. If that is the ‘more sophisticated’ argument then that just shows what I mean about people not justifying their positions properly and jumping to conclusions.

    The level of climate is far more important than the rate of change in climate (followed by acceleration, then higher order derivatives). If we are currently below the optimal global temperature for life on Earth (which we might be given the Earth’s evolutionary history since the Cambrian explosion) then the level-effect of increasing temperatures will be good while the ‘rate-of-change’ effect will be bad. The net effect is that it is a priori indeterminant as to whether warming is good or bad; thus one needs to use empirical data and appropriate methodology to determine the best course of action.

    “and that the range of parameter space over which these changes could be bad is probably significantly greater than the range over which it could, by chance, be good.”

    What metric of good and bad are you using to make this statement?

    “Bear in mind that we can’t survive if the wet bulb temperature exceeds 35oC.”

    Yes and global average temperature is 15 C. Humans are a tropical species that like room temperature (~23 C). We have a long way to go before the Earth becomes unlivable to humans. Arguably, since global temperatures are much lower than temperatures preferred by humans, a small increase will make the planet more comfortable for humans to live.

  44. BBD says:

    I wrote why this is exactly a few months ago

    Why don’t you link to your blog? I have an idea who you may be and am curious to see if it is correct.

  45. BBD says:

    Arguably, since global temperatures are much lower than temperatures preferred by humans, a small increase will make the planet more comfortable for humans to live.

    And a relatively rapid and relatively large one will be extremely disruptive. Where’s this assumption come from that the change will be small come from?

  46. -1=e^ipi says:

    “You are being trolled by -1.”

    No.

    “The idea that “fewer but more intense” is a good news story is ridiculous.”

    If a bad event becomes fewer and more intense, then it is a priori indeterminant if the net effect is good or bad. So I wouldn’t a priori exclude such a position as ridiculous.

    “If you had to choose, surely you would select the exact opposite – more storms but less intense since “less intense” is what our defences are currently built to cope with.”

    No, it depends on how much more intense vs how much less frequent. It’s a tradeoff.

  47. Michael 2 says:

    By the way, what is the significance of “-1=e^ipi “?

  48. -1=e^ipi,

    So just take into account the uncertainty when doing a cost-benefit analysis and go with the policy that has the highest net-benefit.

    Ideally, yes, but I’m not convinced that we can project economic models more than a few years ahead.

    That by itself is no where near sufficient to justify mitigation policy. If that is the ‘more sophisticated’ argument then that just shows what I mean about people not justifying their positions properly and jumping to conclusions.

    I didn’t say it was a justification for mitigation. My reason for saying that was to illustrate that the change is not normal. We’ve never experienced such a change before, in either magnitude or speed. That doesn’t mean it would be bad, but should suggest some thought should go into whether or not we should risk that the consequences could be severe.

    Yes and global average temperature is 15 C. Humans are a tropical species that like room temperature (~23 C). We have a long way to go before the Earth becomes unlivable to humans. Arguably, since global temperatures are much lower than temperatures preferred by humans, a small increase will make the planet more comfortable for humans to live.

    I think you misunderstand. As I understand it, there are no regions of the planet that currently experience wet bulb temperatures that exceed 35oC. I think the highest so far is 31oC. However, a warming of 5K (which is possible if we continue to follow a high emission pathway) could lead to some regions of the planet having extended periods where the wet bulb temperatures exceed 35o. Try reading this.

  49. -1=e^ipi says:

    @ BBD –

    “Why don’t you link to your blog? I have an idea who you may be and am curious to see if it is correct.”

    It wasn’t a blog and if I wasn’t using the same user name then it was not me.

    “And a relatively rapid and relatively large one will be extremely disruptive.”

    Yes.

    “Where’s this assumption come from that the change will be small come from?”

    No where. I am making no such assumption. All I’m saying is that what to do is a priori indeterminant. So you should look at the empirical evidence and then perform a Cost-Benefit analysis.

  50. M2,

    By the way, what is the significance of “-1=e^ipi “?

    It comes from this

    e^{i \pi} = \cos \pi + i \sin \pi = -1

  51. verytallguy says:

    So, everyone more interested in playing climateball with imaginary guy than relieving me if my ignorance on the topic at hand then.

    Or is there a taker amongst the cognoscenti here to give me a hand?

    https://andthentheresphysics.wordpress.com/2015/02/05/atmospheric-heat-engine/#comment-46673

  52. -1=e^ipi says:

    @ ATTP –

    “Ideally, yes, but I’m not convinced that we can project economic models more than a few years ahead.”

    And some are not convinced that people can project climate models more than a few years ahead. That doesn’t mean you can’t. You just have to treat the uncertainty appropriately. Also, if it were not possible to project economic models more than a few years then how can we come up with CO2 emission scenarios to be able to run climate models on? And honestly, the economic models needed do not have to be anywhere near as complicated as the climate models to perform a reasonable CBA.

    “That doesn’t mean it would be bad, but should suggest some thought should go into whether or not we should risk that the consequences could be severe.”

    Yes, I agree. Which is why I suggest thought is used to perform a proper cost benefit analysis to make conclusions about what policies to implement.

    “As I understand it, there are no regions of the planet that currently experience wet bulb temperatures that exceed 35oC. I think the highest so far is 31oC. However, a warming of 5K (which is possible if we continue to follow a high emission pathway) could lead to some regions of the planet having extended periods where the wet bulb temperatures exceed 35o.”

    And we also have tens of millions of uninhabitable frozen tundra that could become habitable and be able to sustain more biomass if the planet warmed. Canada and Russia are the two largest countries on Earth and they are largely uninhabited for this reason. Antarctica is an entire continent that is uninhabited due to it being so darn cold. Why do you think the USA has 10 times the population of Canada? Could it have something to do with most of Canada being a frozen wasteland? Warming the planet has both costs and benefits, and both should be taken into account when deciding upon the best policy.

  53. -1=e^ipi,

    And some are not convinced that people can project climate models more than a few years ahead. That doesn’t mean you can’t.

    Sorry, but I think that there is a massive difference between physically motivated climate models and economic models.

    And we also have tens of millions of uninhabitable frozen tundra that could become habitable and be able to sustain more biomass if the planet warmed.

    You do realise that a high emission pathway means that we could reach wet bulb temperatures in excess of 35oC by 2100 and that some of the regions affected would be the Eastern seaboard of the USA. I find it hard to believe that following a high emission pathway that requires hundreds of millions (if not billions) moving north in the next century is economically preferred to simply finding a way to provide energy without increasing atmospheric CO2 concentrations. You might think we should do a full cost benefit analysis but some things just seem rather self-evident.

  54. wehappyfew says:

    Attp,

    I have a simple (maybe too simple – I am a very simple person) observation:

    You initial calculation for higher surface temp (heat source Th) and higher troposphere heat sink(Tc) is based on the final equilibrium state, not the transitory state we are in now.

    The immediate effect of GHGs is to raise the height of, and thus lower the temperature of the tropopause, reducing outgoing IR, thus retaining more heat in the system. So initially, we have higher surface temps and lower temps at the tropopause. (assuming I’ve got the physics right, never a perfectly safe assumption)

    2nd observation (just thought of it while typing)…

    The ocean is a thermal flywheel, warming slower than the land, so one of the many complications is a higher ocean-to-land temperature differential, which might provide more energy to some kinds of weather.

    And greater contrast between NH and SH…

    … and another big-bad problem we face now is from the reduction in Arctic albedo, pushing heat into new places, and apparently driving the cold into very uncomfortable places (for East Coast US’ers at least).

    I think there are good reasons why climate and weather are too complex to model with one-simple-trick equations (as we know thanks to the Good Lord Mockton).

  55. BBD says:

    -1

    Tundra does not magically transmute into fertile agricultural land when it thaws. It also releases very large amounts of carbon as the permafrost melts. Carbon cycle feedbacks cannot be blithely ignored as you seem to be doing in favour of fantasising about the agricultural bounty we wond’t be reaping from non-cultivable acidic peat bogs up North.

  56. Steven Mosher says:

    “And changing the words doesn’t make it “not a strawman” :-)”

    If I wasnt posting and driving I would have fixed all the problems.
    The main goal was to de personalize..

    Although now that I’ve finished writing something about Booker, I’m not so sure
    I want to champion depersonalization.

    hmm.. looking at it all the zing would go out of the piece…

  57. wehappyfew,

    You initial calculation for higher surface temp (heat source Th) and higher troposphere heat sink(Tc) is based on the final equilibrium state, not the transitory state we are in now.

    Technically, the results of the paper were based on projected warming scenarios, but we’d expect lapse rate feedback to operate as we warm, not only once we’ve warmed.

    The immediate effect of GHGs is to raise the height of, and thus lower the temperature of the tropopause, reducing outgoing IR, thus retaining more heat in the system. So initially, we have higher surface temps and lower temps at the tropopause.

    No, that’s not quite true. If the lapse rate stays the same, then the temperature increases equally everywhere in the troposphere (and reduces in the stratosphere). Lapse rate feedback suggests it should warm more at higher altitudes than at lower.

    as we know thanks to the Good Lord Mockton

    I really hope you’re joking.

  58. Steven,

    If I wasnt posting and driving I would have fixed all the problems.
    The main goal was to de personalize..

    I realised.

    Although now that I’ve finished writing something about Booker, I’m not so sure
    I want to champion depersonalization.

    I understand.

  59. -1=e^ipi says:

    “You do realise that a high emission pathway means that we could reach wet bulb temperatures in excess of 35oC by 2100”

    Yes but there are very few places where this could occur. We are only look at ~2C warming by end of century and there are very few places on Earth with global average temperatures high enough for this to occur especially since the polar regions warm much faster than equatorial regions.

    “some of the regions affected would be the Eastern seaboard of the USA.”

    I was not aware of that. What evidence to you base this claim off of?

    “I find it hard to believe that following a high emission pathway that requires hundreds of millions (if not billions) moving north”

    Again, this is a huge conjecture. Why do you think the high emission pathway requires hundreds of millions or billions of people migrating north? And is so, is the cost of migration more than the cost of mitigation?

    “is economically preferred to simply finding a way to provide energy without increasing atmospheric CO2 concentrations. You might think we should do a full cost benefit analysis but some things just seem rather self-evident.”

    To me, what to do is a priori indeterminant. So I do not know (nor do I think most other people know) what is the best policy. Thus my preference that a CBA is performed before people jump to conclusions.

  60. -1=e^ipi,
    You could read this paper. I realise that they’re considering an extreme scenario, but the conclusion is

    A global-mean warming of only 3–4 °C would in some locations halve the margin of safety (difference between TWmax and 35 °C) that now leaves room for additional burdens or limitations to cooling. Considering the impacts of heat stress that occur already, this would certainly be unpleasant and costly if not debilitating. More detailed heat stress studies incorporating physiological response characteristics and adaptations would be necessary to investigate this. If warmings of 10 °C were really to occur in next three centuries, the area of land likely rendered uninhabitable by heat stress would dwarf that affected by rising sea level. Heat stress thus deserves more attention as a climate-change impact.

    Where’s VTG? 🙂

  61. -1=e^ipi says:

    @ wehappyfews –

    I thought that in the transient state the increase in water vapour, particularly around the tropopause, makes the upper troposphere more opaque and therefore warm faster than the surface, especially around the tropics. So the gradient is still reduced.

    @ BBD –

    “Tundra does not magically transmute into fertile agricultural land when it thaws”

    Yes. I never claimed it does.

    “It also releases very large amounts of carbon as the permafrost melts.”

    Yes. I am aware of positive feedbacks.

    “Carbon cycle feedbacks cannot be blithely ignored as you seem to be doing”

    I am not doing that.

    “in favour of fantasising about the agricultural bounty we wond’t be reaping from non-cultivable acidic peat bogs up North.”

    Actually, many places are too cold to even have peat-bogs. But with respect to agriculture. A priori the net effect on global agricultural production is indeterminant. Longer growing seasons in places like Canada and Russia will help increase yields, and the CO2 fertilization effect should also have a positive effect globally. The effects are very complicated, which is why I think a proper CBA should be done before people jump to conclusions.

  62. Eli Rabett says:

    There is a simple physical basis for this, as Eli pointed out a few days ago. The atmospheric heat engine is driven by temperature differences not total energy so fewer storms makes sense. OTOH the size of fluctuations varies with energy content so more intense storms make sense. Add to this the fact that most clouds are withing 1 to 2 km of the surface and you have a story.

  63. Eli Rabett says:

    -1 growing anything on the Canadian Shield is an exercise in futility

  64. -1=e^ipi says:

    @ ATTP –
    I always appreciate new information. But with respect to the paper you just linked to, it only looks at costs and not benefits of climate change, which I think is a very biased approach. If you only look at things that are bad and ignore the good, of course one is going to get a skewed understanding that is more favorable to mitigation policy. Humans might not be able to survive outside at 35 C for extended periods of time, but they also can’t survive outside at -20 C for extended periods of time either (such as the temperature outside the warm room temperature building I am currently in).

    Also, I apologize that this comment section is getting derailed due to my initial comment. I never intended on that. Want to just stuck with the current topic?

    @ VeryTallGuy – “The latent Hest release is higher due to moister air at the surface. So what’s the mechanism to weaken the heat engine? ”

    Because the temperature of the air that moves from the surface to the tropopause cannot be lower than the temperature of the tropopause when it is released from the heat engine. So as you increase the temperature of the tropopause, the temperature at which air leaves the heat engine also rises. Since the tropopause warms faster than the surface, the change in temperature of air as it goes through the heat engine reduces.

    Of course if you want to get really fancy, you could also point out that warmer air generally has more water vapour and therefore has a higher heat capacity. The increase in heat capacity should offset the reduction in heat gradient effect somewhat.

  65. -1=e^ipi,

    I always appreciate new information. But with respect to the paper you just linked to, it only looks at costs and not benefits of climate change, which I think is a very biased approach. If you only look at things that are bad and ignore the good, of course one is going to get a skewed understanding that is more favorable to mitigation policy. Humans might not be able to survive outside at 35 C for extended periods of time, but they also can’t survive outside at -20 C for extended periods of time either (such as the temperature outside the warm room temperature building I am currently in).

    Okay, maybe you don’t realise this but if it is -20oC you can put on clothes and survive for hours, nay, even days. I know I’ve been in temperatures that low and even lower. If the wet bulb temperature exceeds 35oC you could be completely naked, covered in water, with a fan blowing on you and you will die.

  66. Nick Stokes says:

    I think there are some global constraints that people (maybe even Laliberte et al) need to bear in mind. The Earth gets sunlight at an effective thermodynamic temperature of 2310K. That is, with focussing etc it could heat fluid to that temperature to drive a heat engine. So it’s mostly free energy, low entropy.

    It moves through the atmosphere etc, creating entropy as it cools, and losing free energy. Eventually, it is emitted at an average BB temperature of 255K, having lost all its free energy (relative to heat sinks on Earth). The entropy that has accumulated goes with it.

    The emission temperature is constrained by Stefan-Boltzmann; for black body at uniform temperature it is 255K. That gives the maximum possible entropy export rate. Any non-uniformity will export less entropy.

    There are theories going back to Paltridge and others in the 60’s saying that the atmosphere tends to a state of maximum entropy production. Put another way, any available free energy (FE) will be used, dirving heat engines.

    If you track the FE, much is lost on original thermalisation. The effective temp drops from 2310K to about 300K. What is left is what sustains winds, life, the whole damn thing.

    Warming the surface reduces this initial FE loss (entropy production). That means more available for atmospheric processes.

    So when they say
    “As the climate warms, the system may be unable to increase its total entropy production enough to offset the moistening inefficiencies associated with phase transitions.”
    that is the wrong direction. Entropy production is constrained. 238 W/m2 exiting at 255K, at MEP, minus 238 W/m2 at 2310K. Water vapor allows air to carry more heat at a given velocity. Poleward transport is part of the entropy maximisation process (exit at uniform temp); wv lets it happen with less KE. So it’s not a limit on energy available for storms; that increases. But it may reduce the KE that is required.

  67. -1=e^ipi says:

    @ ATTP –
    There is always air conditioning. Just make an air-conditioning suit or something. If wearing uncomfortable clothes is reasonable when it is really cold, why is it unreasonable when it is really hot?

    Again, it is all about the costs vs benefits. That’s why I put emphasis on CBAs. Some places are worse off due to increasing CO2 levels, while other places are better off.

  68. Willard says:

    > Implying that the shoe fits has nothing to do with the science..

    What if it’s a glove: should we acquit?

  69. Willard says:

    > Again, it is all about the costs vs benefits.

    Elementary cost-benefit and business economics teach that this is an incorrect criterion for selecting investments or policies. The appropriate criterion for decisions in this context is net benefits (that is, the difference between, and not the ratio of, benefits and costs).

    http://www.nybooks.com/articles/archives/2012/mar/22/why-global-warming-skeptics-are-wrong/

  70. Nick,
    Interesting, although it’s now late enough that I shall have to give it some more thought tomorrow.

    -1=e^ipi,

    There is always air conditioning. Just make an air-conditioning suit or something. If wearing uncomfortable clothes is reasonable when it is really cold, why is it unreasonable when it is really hot?

    Indeed, such technology is possible. Just make sure you don’t have a power cut or it stops working (or build homes underground). I realise that it should be a CBA. Personally, though, I would find it hard to believe a CBA that concluded that moving north and allows us to survive in regions where there will be extended periods where it is no longer habitable for mammals was preferable to simply trying to prevent atmospheric CO2 from rising to levels where this becomes possible.

  71. Nick,

    So it’s not a limit on energy available for storms; that increases. But it may reduce the KE that is required.

    Let me see if I understand what you’re saying here. If you warm you increase the amount of of water vapour that the air can carry. Since condensation releases energy, this means that a given parcel of air moving with a given velocity can actually be carrying more energy in the form of water vapour than would be the case in a cooler world. Is that about right?

  72. Joseph says:

    ‘Trust the science’ is a very ambiguous statement. People should follow the scientific method, but I think what you mean is closer to ‘people should blindly believe what authority figures in science tell them’.

    The blind leading the blind so to speak? But no I admit I don’t have the background to properly evaluate every statement made to me by experts. So in that sense I am blind. But I don’t think the vast majority of scientists would accept a theory unless that theory has some basis in fact. I do that based on the history of modern science. Bad theories rarely last very long in science. I expect that to continue. I do think in general experts have better vision than you or I do. Science also gives “skeptics” the opportunity to overturn the consensus through research. Nor do I blindly accept what they say without testing it for logical consistency whether I understand all of the details or not.

  73. -1’s, “the optimal global temperature for life on Earth”, is a really sloppy concept. In the past when the climate has been much warmer globally, it’s true that ‘life’ has thrived. But look at what sort of life it was: very little of the fossil record is mammals. On the other hand human development, which bumbled along without making headway for tens of thousands of years, suddenly started to advance with the start of the relatively stable, warm climate period we call the holocene, and has progressed increasingly rapidly ever since.

    So the optimal temperature for ‘life’ is a meaningless concept within the last billion years on Earth. You need to be more specific about what sort of life you’re rooting for. As humans have thrived during the Holocene it would be logical to believe it’s our optimal global temperature. To maintain, complacently, that there’s no harm in carrying out an irreversible global experiment to see what happens if we turn the thermostat up, appears reckless in the extreme.

  74. john,

    To maintain, complacently, that there’s no harm in carrying out an irreversible global experiment to see what happens if we turn the thermostat up, appears reckless in the extreme.

    Yes, the irreversible aspect of this is indeed something worth stressing.

  75. BBD says:

    Thousands of years of relentless, unstoppable sea level rise. Our gift to posterity. I’m sure it will aid the future flourishing of the species no end.

  76. Easy. As temperature increases, all the atmospheric conditions will rise in altitude to keep the thermodynamic laws invariant, i.e. cloud banks will increase in altitude by a percentage according to the largely fixed lapse rate.

    So if a golf-ball-sized hail stone forms, by the time it reaches the ground it may pick up a little more speed, in which case you wake up with a larger bump on your head than before global warming kicked in.

    Commenters named after devils can stop reading at this point,.

    As Nick Stokes indicated, keeping track of entropy is the key. Remember that heat capacity has exactly the same units as entropy. The heat capacity moving up and down in altitude will change dramatically depending on how much water vapor is in the air. Any latent heat of phase transformation of the water vapor will modify the effective heat capacity. That’s why they have that odd heuristic equation for lapse rate which includes water.

    Yet there is something to be said for interpreting the average lapse rate as being some sort of maximum entropy value derived from considering the range of possible values of the lapse rate. This ranges from a value of 9.8C/km max for the pure atmospheric constituents down to below the 6.5C/km that the Standard Atmosphere is specified. This 6.5 “average” value has been set in stone since 1928 and has a value that is almost exactly 2/3 of the “dry” rate. Is that a coincidence, or does it have to do with some fundamental maximum entropy averaging that is going on? The additional odd coincidence is that the other planets and possible even the sun shows this same 2/3 ratio when considering the molecular gas composition of each of the respective atmospheres.

    I spent some time researching this on one of my old blogs. I ended up getting into the virial theory of polytropic atmospheres deep enough that worry-warts such as Pekka Pirrilla started tssk-ing me.

    But listen to what Nick is saying because he has some interesting ways of thinking about entropy, i.e. that vortices are manifestations of entropy and that eddy-scale diffusion is the transport mechanism of heat. This is stuff that the skeptics do not want to hear because they assert that infrared energy never penetrates the surface of the ocean.

  77. Here are two elliptical involved posts on the lapse rate coincidence that I wrote up:

    The first: http://theoilconundrum.blogspot.com/2013/03/standard-atmosphere-model-and.html

    The second: http://theoilconundrum.blogspot.com/2013/05/the-homework-problem-to-end-all.html

    I was essentially trying to find if there was some maximum entropy trick to manipulating thermodynamic variables so as to get an invariant average lapse rate value that would work across different planetary atmospheres.

  78. Nick Stokes says:

    ATTP,
    “Is that about right?”
    Yes. Heat transport by wind is approx ρs v.∇T, where s is specific heat capacity of air. Water, going from vapor to liquid, effectively increases s by a lot. Other things equal, if s increases, v can decrease for the same heat flux.

  79. -1=e^ipi says:

    @ Willard, I never said anything about costs divided by benefits. I don’t know where this is coming from.

    @ ATTP – I’m glad that you agree a CBA should be done. 🙂

    @ John Russel
    “But look at what sort of life it was: very little of the fossil record is mammals.”

    What about the Eocene?

    “As humans have thrived during the Holocene it would be logical to believe it’s our optimal global temperature.”

    No, because humans never existed before the Pleistocene (pre-hominid species did though). So humans have only lived on an Earth that was either ~ Holocene temperature or colder (as it was during ice ages). The most you could infer is that Holocene temperatures are preferable to colder temperatures. But you don’t know if increasing temperatures slightly above Holocene temperatures is good or bad.

    “there’s no harm in carrying out an irreversible global experiment to see what happens if we turn the thermostat up, appears reckless in the extreme.”

    Good thing I’m not suggesting that. I suggest that a CBA done to evaluate what is the best policy. I’m also not sure if ‘irreversible’ is the correct word to use here though since there are always geoengineering options.

    @ BBD –
    “I’m sure it will aid the future flourishing of the species no end.”

    Yes, the fish will be very happy. 🙂

  80. -1=e^ipi says:

    @ WebHubbleTelescope –

    “Easy. As temperature increases, all the atmospheric conditions will rise in altitude to keep the thermodynamic laws invariant”

    I know this is a decent approximation, but density should still change, right?

    “So if a golf-ball-sized hail stone forms, by the time it reaches the ground it may pick up a little more speed”

    Never thought of that. I’ll be sure to wear a hard hat. Wouldn’t there be more time & energy to melt the hail before it gets to you though?

  81. uknowispeaksense says:

    Anders… the sign of an expert troll is that they manage to get numerous points across very subtly, bit by bit. So far, your expert troll has appeared as a lukewarmer but probably isn’t. They have brought up Al Gore, have equated AGW proponents with antivaxxers, subtly painted climate science as a religion, raised the “it won’t be bad on balance” canard, questioned the models and 3 or 4 other flags that I can see. While his demeanor appears benign, the garbage he is writing isn’t.

  82. Willard says:

    > I never said anything about costs divided by benefits.

    Don’t be so defensive, Minus One.

    Here’s another quote from the same op-ed:

    My research shows that there are indeed substantial net benefits from acting now rather than waiting fifty years. A look at Table 5-1 in my study A Question of Balance (2008) shows that the cost of waiting fifty years to begin reducing CO2 emissions is $2.3 trillion in 2005 prices. If we bring that number to today’s economy and prices, the loss from waiting is $4.1 trillion. Wars have been started over smaller sums.

    http://www.nybooks.com/articles/archives/2012/mar/22/why-global-warming-skeptics-are-wrong/

    Would that count as alarmist to you?

  83. -1=e^ipi says:

    @ Willard –

    You can pretend I don’t understand how to do a CBA if you want to.

    With respect to that specific net benefit, I haven’t read it so I do not know if it is done properly. It is very easy to perform a terrible cost benefit analysis, especially with an issue as politicized as Climate Change and where there is a big disconnect between the people that are doing the economics and the people that are doing the physics.

  84. MikeH says:

    @-1

    No, it depends on how much more intense vs how much less frequent. It’s a tradeoff.

    Well yes. Since we cannot predict the future with absolute certainty, it is about risk. I was dealing with the implication in your opening troll/comment that this paper indicated fewer extreme events.

    I don’t think that is necessarily true, at least based on the lead author’s comments here

    “Put more simply, powerful storms are strengthened at the expense of weaker storms,” said Laliberte. “We believe atmospheric circulation will adapt to this less efficient form of heat transfer and we will see either fewer storms overall or at least a weakening of the most common, weaker storms.”

    http://www.sciencedaily.com/releases/2015/01/150129143040.htm

    So perhaps not even fewer storms. They are confident however that the stronger storms will get stronger consistent with the IPCC reports – which is not surprising since their research was motivated by this outcome in the models (see the Smithsonian article). Although not all the models – see the Emmanuel paper for example.

    So potentially the number of extreme events could increase.

    Didn’t the IPCC change its positive from ‘the intensity and frequency of hurricanes is expected to increase’ to ‘climate models show that the intensity and frequency of hurricanes will either stay the same or decrease’?

    I think from memory the other way around. The IPCC reports have pointed to “fewer, but more intense” for a while. The fewer is now being challenged.
    e.g. from 2007 SPM “likely increase in tropical cyclone intensity; less confidence in global decrease of tropical cyclone numbers”

  85. -1=e^ipi says:

    Sorry, meant ‘specific CBA’ rather than ‘specific net benefit’ in my last post.

  86. Willard says:

    I have no idea why you’re so defensive, Minus One.

    I was asking you if the quote you just read sounded alarmist to you.

    Here’s the next paragraph:

    My study is just one of many economic studies showing that economic efficiency would point to the need to reduce CO2 and other greenhouse gas emissions right now, and not to wait for a half-century. Waiting is not only economically costly, but will also make the transition much more costly when it eventually takes place. Current economic studies also suggest that the most efficient policy is to raise the cost of CO2 emissions substantially, either through cap-and-trade or carbon taxes, to provide appropriate incentives for businesses and households to move to low-carbon activities.

    http://www.nybooks.com/articles/archives/2012/mar/22/why-global-warming-skeptics-are-wrong/

    Does this paragraph sound alarmist to you?

  87. Oale says:

    ‘Atmospheric Heat Engine’ was an kinetic scupture in which Maxx Lange built a contoured representation of the earth surface and oceans in an encased box, filled the ‘oceans’ with distilled water an set some sailed bark ships on it. Then he set an infrared emitting glasstube over the equator and two fridge cooling engines over the poles and watched the ships sail on it. The sculpture was destroyed in the bombings of Dresden physical chemistry building when someone running to the shelter accidentally spilled some sulfuric acid solution cooled with dry ice over it. These naturally destroyed the sealed metal joints in the casing and destroyed the electrical connection powering the infrared lamp. Thus the scupture was not considered very succesful by the staff and they decided to discard it. The remains of this we’re found by Revelle who attempted to replicate it, but found it lacking in that it didn’t simulate the nights. The rest is history.

  88. -1=e^ipi says:

    @ Willard – No, I do not see a reason to believe that the paragraph is alarmist. Why do you ask?

  89. Brandon Gates says:

    -1=e^ipi,

    All I’m saying is defining ‘extreme weather’ as a certain variation from the historic mean is misleading/flawed.

    Yes, climate is always changing.

    What if you go from A to B to A, does that mean you have more extreme weather even though you have the exact same climate?

    “What if” B kills every living human on the planet by deep-freezing us? Will trees falling in the forest upon return to the “normal” A make any sound?

    Basically, any useful definition that tries to quantify ‘extreme weather’ needs to have the transitive property.

    Then please tell us your useful definition of extreme weather so that your wisdom is no longer reserved. Be sure it is not based on any arbitrary baselines so that it cannot be attacked by insinuations of equivocation despite the fact that you have explicitly defined it. Thanks.

  90. Rachel M says:

    A bit OT sorry but I read a post recently about the link between anti-vaccine ideology and right-wing conservatism:
    https://faustusnotes.wordpress.com/2015/02/04/is-anti-vaccine-ideology-the-next-step-in-republican-denialism/

  91. Andrew Dodds says:

    Rachel –

    That’s interesting, because the anti-vax brigade was long associated with ‘hippy types’ – the idea being that the diseases were natural and vaccines unnatural. Mind you, many religious conservative types have held similar views.. painful early death/disfigurement from preventable disease being part of the Great Ineffable Plan, apparently.

    Me neither.

    Now, a REAL conspiracy theorist would point out that the profits to Big Pharma(tm) from vaccines are actually quite marginal, and there are much greater profits to be had from treating all the complications of people getting things like measles (never mind polio – they nearly let that one go extinct!), so could they be the ones really funding vaccine denial..?

  92. BBD says:

    -1

    Yes, the fish will be very happy.

    But not humanity. And for you, the appropriate tone is childish flippancy. Thanks for the insight.

  93. Brandon Gates says:

    Nick,

    If you track the FE, much is lost on original thermalisation. The effective temp drops from 2310K to about 300K … Warming the surface reduces this initial FE loss (entropy production). That means more available for atmospheric processes … Entropy production is constrained.

    It may not be correct to use such a global constraint. Though the paper itself is paywalled, there is a supplemental which is open-access: http://www.sciencemag.org/content/suppl/2015/01/28/347.6221.540.DC1/Laliberte-SM.pdf

    I paraquote the first two bullet points from their stepping-through the Carnot cycle (emphasis mine):

    1. The first step is to add a small amount of liquid water to the air parcel isothermally at input temperature T in and isobarically at input pressure Pin.

    2. Since the air parcel is unsaturated, the added liquid water will evaporate and expand at constant [wet-air enthalpy] and constant [water vapor content]. This process is irreversible because it is physically impossible to convert the water vapor back to liquid water without bringing the air parcel to saturation first. Adding water vapor to unsaturated air therefore results in the production of irreversible entropy.

    Hold that thought. Next you write:

    Water vapor allows air to carry more heat at a given velocity.

    Agree. In a different comment you then say to ATTP:

    Heat transport by wind is approx ρs v.∇T, where s is specific heat capacity of air. Water, going from vapor to liquid, effectively increases s by a lot. Other things equal, if s increases, v can decrease for the same heat flux.

    But other things are not equal. We’re assuming solar flux is constant, which is fine, but we’ve got an additional forcing from well-mixed GHGs globally, including over the tropics. We’ve got a wv feedback radiative forcing weighted toward the tropics, with a negative lapse rate feedback in the same latitudes. Let’s make it easy and assume cloud feedbacks are nil.

    The argument as I understand it is the additional energy gained in latent heat can only do work if we desaturate our air parcel from (2) above. By what I just wrote above, the tendency is that poleward transport becomes the more dominant mechanism. Which leads to your ultimate comment:

    Poleward transport is part of the entropy maximisation process (exit at uniform temp); wv lets it happen with less KE.

    Assuming this theory … holds water … there cannot be any change in KE due to the additional entropy of the wv itself, so now we invoke the global constraint of solar-derived FE for entropy production. We’re moving more heat around with the same KE. Or in engine speak, doing the same work even though more energy has been pumped into to the system, which is less efficient.

    Reduction in storm frequency due to the negative lapse rate feedback in lower latitudes. When storms happen, they’re larger and more violent, and also tend to happen at higher latitudes. Or such is my understanding, I’ve likely mucked up something. I took some hints from this editorial comment in the same issue of the journal:

    http://www.sciencemag.org/content/347/6221/475

    It has been widely accepted since Carnot’s seminal work (1) that the atmosphere acts as a thermodynamic heat engine: Air motions redistribute the energy gained from the Sun in the warm part of the globe to colder regions where it is lost through the emission of infrared radiation to space. Through this process, some internal energy is converted into the kinetic energy needed to maintain the atmospheric circulation against dissipation. The analogy to a heat engine has been applied to explain various atmospheric phenomena, such as the global circulation (2), hurricanes (3), and dust devils (4). On page 540 of this issue, Laliberté et al. (5) show that the hydrological cycle reduces the efficiency of the global atmospheric heat engine.

  94. Andrew Dodds says:

    @EyePie –

    Bear in mind that the cost-benefit analysis of decarbonisation has to include both the costs of acute pollution, and the political costs as well. Acute pollution includes things like particulates, smog, acid rain, etc; political costs are those like stationing fleets in the Persian Gulf for the protection of our freedom-loving Saudi friends (Don’t mention the flogging) (or ISIS).

    Or, in the case of the UK, tip toeing around Vlad’s involvement in the Ukraine..

    There is a more technical economic argument as well. At the moment, the cost of energy is basically determined by the cost of fossil fuels – be it minehead cost of coal, well head cost of oil or gas – and no matter how good and efficient the rest of your economic chain is, there is a fundamental cost there. I strongly suspect that this puts a cap on the possible standard of living for the population at large – after all, if the basics of life depend on energy and energy has a floor cost and limits to availability, then it follows that the standard of living will be capped.

    This would explain why my lifestyle is similar in many ways to that of my parents, just with more consumer electronics.

    So – if we move to energy sources that are not fuel bound (which includes breeder reactors of various types, renewables, et. al.) then it follows that there is far more room for real economic expansion, because technology can then push the cost of energy down to an asymptote of zero (how much does a transistor cost nowadays, anyway? )

  95. Everett F Sargent says:

    This one is way above my pay grade.

    However, having said that, the underlying data are fixed, that being the AOGCM CMIP5 database. An analysis of the fixed underlying database exposes new understandings of that fixed database, So GMT and other common metrics don’t change one iota. Also, unless I’m missing something, the thermodynamic equations, must be an integral part of the modelling process to begin with in the 1st place, if not, then WTF?

    But, here’s what I don’t explicitly understand with respect to either weather prediction or AOGCM’s, that being how do thy model precipitation? I mean, it’s certainly not as individual rain drops, so my current conjecture is they model relative humidity, then a parameterization miracle (of sorts) occurs, and moisture falls to the ground. Given the rather course grid structure of these models, specifically at the AOGCM level, I will remain somewhat suspicious of drawing too many conclusions (other than say GMT, and water is over here and land is over here and atmosphere is over here) through different detailed analyses of what I consider to currently be a very imperfect modelling paradigm.

    So I await CMIP6, … , CMIP666, with (at least) much higher grid resolutions, and deeper understandings of biases between these further numerical efforts coupled to further advances in observational methods. (note this does not change my basic view that action be taken now)

    Anyone have good intermediate-to-advanced textbook references focused on (specifically parameterizations and other modelling assumptions) generic AOGCM’s (not much interested in specific AOGCM’s as there are so many to begin with in the 1st place), that they could recommend (specifically aimed at both/either finite difference and spectral element methodologies (really want I want is a better understanding of SEM’s))?

  96. Nick Stokes says:

    Brandon,
    “Adding water vapor to unsaturated air therefore results in the production of irreversible entropy.
    Hold that thought”

    No, I can’t. The water vapor does not irreversibly remain in the air. It rains.

    As to irreversible entropy, that’s part of my comment above. Entropy is being produced all the time, and it’s irreversible in the Universe. But it doesn’t accumulate on Earth (else …). It is exported to space.

    “The argument as I understand it is the additional energy gained in latent heat can only do work if we desaturate our air parcel from (2) above.”
    Well it does some then. Thunderstorms. But it does quite a lot in various ways. wv is bouyant, and helps drive the Hadley cells. The Hadley cells run further, because the moist air condenses, transferring LH to the air, so it doesn’t descend (because of IR cooling) until higher latitudes.

    Here is Hadley cell as Carnot engine:
    1. Tropical rise. Air charged with heat (sensible and latent) rises adiabatically. It cools as it goes, but rises until its temperature reaches ambient. If wv condenses with cooling, the LH allows further rise. KE gained.
    2. The rise creates higher pressure aloft. This drives a poleward wind. Heat is transferred to space by IR. And remaining wv will chip in its LH
    3. The cooled (heavy) air at mid-lat descends. Again KE gained, and pressure created at low level.
    4. With pressure gradient, air returns (trade wind), gaining heat and moisture from the surface, and back to 1.

  97. verytallguy says:

    Nick,

    a couple of questions vs carnot cycle:

    If we consider the source temperature to be the surface temperature in the topics, is the sink temperature better thought of as the
    – deep space temperature (IR to space)?
    – tropopause temperature?
    – pole temperature?

  98. John says:

    -1

    There is always air conditioning. Just make an air-conditioning suit or something.

    Never thought of that. I’ll be sure to wear a hard hat.

    Yes, yes, of course! If global warming is bad, we can just wear air-conditioned suits and hard hats. And if sea level turns keeps rising, just throw on a pair of fishing waders or something. The solutions are simple. Why can’t you alarmists get this through your religiously-fervent heads!

  99. Andrew Dodds says:

    @John –

    Well, even if we destroy the entire atmosphere, biosphere and hydrosphere we can just walk around in spacesuits and import water by comet mining. What’s the problem?

  100. -1=e^ipi says: Since many climate phenomena are basically giant heat engines, if you reduce the polar-equatorial heat gradient or the surface-tropopause heat gradient then one would expect that these climate phenomena get weaker/less frequent. Of course this basic physics is inconvenient for the climate alarmists who often claim that global warming will cause the Earth’s climate to become more extreme in every since way.

    Just for the record and for the lurkers who would like to judge who is credible, while I could show that I, as a climate scientists did talk about the polar-equator heat gradient, -1=e^ipi never acknowledged being wrong nor replied that climate scientists are not “climate alarmists”

  101. Willard says:

    > No, I do not see a reason to believe that the paragraph is alarmist. Why do you ask?

    Because I have no idea why you’d peddle alarmism if you dig CBA, and why you would bitch about Pascal’s wager (which, unless you’re a philosopher or a decision theorist, you may not have studied) or green-bash Suzuki instead of looking at what someone like Nordhaus says.

    I hope you noticed Nordhaus’ conclusion about the need to mitigate ASAP.

    ***

    Another quote:

    One might argue that there are many uncertainties here, and we should wait until the uncertainties are resolved. Yes, there are many uncertainties. That does not imply that action should be delayed. Indeed, my experience in studying this subject for many years is that we have discovered more puzzles and greater uncertainties as researchers dig deeper into the field. There are continuing major questions about the future of the great ice sheets of Greenland and West Antarctica; the thawing of vast deposits of frozen methane; changes in the circulation patterns of the North Atlantic; the potential for runaway warming; and the impacts of ocean carbonization and acidification. Moreover, our economic models have great difficulties incorporating these major geophysical changes and their impacts in a reliable manner. Policies implemented today serve as a hedge against unsuspected future dangers that suddenly emerge to threaten our economies or environment. So, if anything, the uncertainties would point to a more rather than less forceful policy—and one starting sooner rather than later—to slow climate change.

    http://www.nybooks.com/articles/archives/2012/mar/22/why-global-warming-skeptics-are-wrong/

    Do you find any alarmism in that paragraph?

    (MikeR might appreciate how what Nordhaus says about uncertainty lukewarmingly undermines his insistence on constraining sensitivity.)

  102. Pingback: How Should the Public Interact with Scientists? | Compromise and Conceit

  103. Joshua says:

    -1

    ==> “Of course this basic physics is inconvenient for the climate alarmists who often claim that global warming will cause the Earth’s climate to become more extreme in every since way.”

    I think that if you don’t want to distract, even if you make a statement such as that you can just walk it back: “It was a stupid and inflammatory thing to say. Apologies. Sometimes it happens. We’re all tribal at times, and sometimes my tribalism gets the better of me. But I do try to control for it, and thanks for the feedback. So now, let’s talk about the science, shall we?”

    It would have gone better, IMO.

  104. Brandon Gates says:

    Nick,

    The water vapor does not irreversibly remain in the air. It rains

    My fault for not fully qualifying. The way I read the authors’ argument, the entropy is irreversible until saturation is reached. At which point it rains. This paper may be wrong about how GHG forcing + feedbacks in the tropics reduces that. Your Hadley cell explanation, or some other part of your argument, may be the more correct physical — I’m not fluent enough with the maths or the theory to argue that piece of it. IF this research is correct, I believe it does challenge your argument that solar FE is a global constraint on entropy production. That’s mainly what I had to say and all I have the chops to reasonably argue.

    This is an enticing paper to me since it might explain (lack of) trends in observed tropical cyclone frequency.

    Thank you for the additional info on the ful cycle as you understand it in this context. That helps.

  105. Willard says:

    > Entropy is being produced all the time, and it’s irreversible in the Universe.

    This does not apply to Grrrowth.

    ***

    > But it doesn’t accumulate on Earth (else …).

    Else, not Grrrowth on Earth.

    ***

    > It is exported to space.

    Why do you think Sir Richard Branson launched there?

  106. BG says:

    Of course, let’s do a CBA. Realizing that ‘C’ = Cost. ‘Cost’ = ‘Economic Analysis’. ‘Economic Analysis’ means writing ‘equations of motion’ that include the human reactions of fear, panic, greed, hate, prejudice, the economic system,….. and so on. Meaning that any outcome is highly susceptible to GIGO.

    A CBA is the last refuge of……..

    Our Whiz Kids in the US Pentagon did lots of CBAs in the ’60s and ’70s which justified the US Vietnam War. How’d that work out? Millions killed in SEA and 57,000 kids’ names on a Black Wall on the Mall in DC.

    The Bush Administration calculated (obviously never shown to the US public) that the benefit of removing Saddam Hussein would far exceed the cost. How is that working out?

    How would that work out if Canada were told 10s of millions of us USers were coming to ‘visit’ on a permanent basis?

    Just bear in mind that cities in the SE US never amounted to much until the advent of AC. It will not take a lot to make it pretty unbearable there. I know, I lived there without AC.

  107. David Blake says:

    [Mod : Sorry, a bit too much of a conspiracy rant.]

  108. -1=e^ipi says:

    @ Brandon Gates –

    “Then please tell us your useful definition of extreme weather”

    I don’t have the ultimate definition of extreme weather, but any useful definition should satisfy the transitive property and not be based on some arbitrary point in the past.

    For example, defining wet-bulb temperatures above 35 C as extreme weather because humans will die in it is fine.

    @ BBD –

    “But not humanity.”

    How do you know? Humans are a tropical species that evolved primarily in Eastern Equatorial Africa. Why else do you think humans are relatively hairless and have sweat glads all over.

    @ Andrew Dods –

    “political costs are those like stationing fleets in the Persian Gulf for the protection of our freedom-loving Saudi friends”

    Or we could just get oil from Alberta and North Dakota. But the politicians think it is much better to not build pipelines so things get transported by rail…

    “if the basics of life depend on energy and energy has a floor cost and limits to availability, then it follows that the standard of living will be capped.”

    Maybe. Depends on how you are defining the standard of living.

    “if we move to energy sources that are not fuel bound then it follows that there is far more room for real economic expansion.”

    No it doesn’t. This is a very oversimplistic way of looking at things. When you think of the cost of 1 source of energy vs another, fuel costs are not the only cost that should be considered.

    “because technology can then push the cost of energy down to an asymptote of zero”

    Why do you think this? There are physical limits in the universe. Conservation of energy or the second law of thermodynamics will make it difficult for the cost of energy to approach zero.

  109. Arthur Smith says:

    On the original question here – I completely agree with Nick Stokes that a warmer planet has more free energy available to do work overall. The relevant Carnot reference temperatures are roughly Earth’s surface temperature in the tropics (high temperature heat bath) and the point in the atmosphere of average radiation to space (low temperature heat bath). That latter temperature is fixed in steady state at 255 K independent of GHG concentrations (though there is an albedo dependence). The fact that the surface is warming means there is definitely more free energy and more ability for atmospheric heat engines to do work. I’m not sure this was accounted for in the paper being discussed.

    However, what the paper does seem to analyze is the breakdown of “work” between moving chunks of the atmosphere around (circulation) and the water cycle (evaporation and precipitation). The argument is that a greater fraction of the total available is going into the water cycle as Earth warms, so there’s less available for circulation. The reasoning does not seem entirely obvious to me though.

    A very large fraction of the Sun’s incoming energy goes to the water cycle already; I’ve long wondered if instead of trying to get energy from wind (pulling useful energy out of the atmospheric circulation) we might be better off finding some way to extract energy from the water cycle – some new form of hydroelectricity that can catch a more complete fraction? Other than creating artificial mountains I haven’t had any actual practical ideas on this though…

  110. Arthur,

    I completely agree with Nick Stokes that a warmer planet has more free energy available to do work overall. The relevant Carnot reference temperatures are roughly Earth’s surface temperature in the tropics (high temperature heat bath) and the point in the atmosphere of average radiation to space (low temperature heat bath). That latter temperature is fixed in steady state at 255 K independent of GHG concentrations (though there is an albedo dependence).

    Yes, this does make sense now that you put it like that.

    The argument is that a greater fraction of the total available is going into the water cycle as Earth warms, so there’s less available for circulation. The reasoning does not seem entirely obvious to me though.

    Yes, I’m a little confused now. I think I had assumed that lapse rate feedback meant that the cool reservoir (upper atmosphere) warmed more than the hot, but as you point out that doesn’t necessarily make sense since the radiative temperature remains fixed at 255K. Could it be that the kinetic processes are restricted to be within some altitude and that that then means that the effective cool reservoir warms faster than the warm reservoir? Also, what about polar amplification? Could it be that this is more to do with reducing the latitudonal temperature gradient than the vertical temperature gradient?

  111. -1=e^ipi says:

    @ Victor Venema –

    “nor replied that climate scientists are not “climate alarmists””

    It depends on the climate scientist. Not all climate scientists are climate alarmists and not all climate alarmists are climate scientists. Climate scientists can believe in all kinds of religions (Islam, Christianity, Sikhism, Climate Alarmism, Homeopathy, etc.).

    @ Willard –

    “why you would bitch about Pascal’s wager”

    Because the arguments many give to justify mitigation policy take the same form as Pascal’s wager. Both arguments are nonsense because they create a false premise of only 2 possible outcomes and then they ignore the probability of different outcomes.

    “I hope you noticed Nordhaus’ conclusion about the need to mitigate ASAP.”

    Yes, I can read.

    “Do you find any alarmism in that paragraph?”

    Mostly just opinion. Though I would suggest that going on about a run-away greenhouse effect as a significant possibility is alarmism.

  112. verytallguy says:

    ATTP,

    I don’t think the TOA radiative temperature is quite fixed. The surface warms, so more IR passes through the “atmospheric window” meaning less leaves from the TOA when in balance, so TOA should be slightly cooler.

    I think.

  113. vtg,
    Interesting point. Yes, possible, but then that – in a simple sense – could suggest that the heat engine should become more efficient.

  114. -1=e^ipi says:

    @ BG –

    People incorrectly doing CBA’s does not discredit the methodology of CBA’s. Much like people doing climate science poorly does not discredit the field of climate science.

    “How would that work out if Canada were told 10s of millions of us USers were coming to ‘visit’ on a permanent basis?”

    Actually, that would probably increase Canada’s economic well-being since Canada suffers greatly from being sparsely populated. Canada would have lower per-capita expenditure on public goods, more competition (this would greatly help for telecommunications), lower average transportation costs, etc. My understanding is that the GDP elasticity of population for Canada is ~ 0.06.

  115. -1=e^ipi says:

    @ Arthur Smith – You mean something like Ocean Thermal Energy Conversion?

  116. Joseph says:

    It seems like it would be difficult to do an accurate CBA when you have a large range of potential costs. Like others have said it about mitigating risks, not against something we know will happen.

  117. Joshua says:

    -1 –

    ==> “Mostly just opinion. Though I would suggest that going on about a run-away greenhouse effect as a significant possibility is alarmism.”

    Says the fella/gal that doesn’t want to distract.

    ==> “going on about…”

    What does that mean?

    ==> “as a significant possibility”

    What does that mean?

    ==> “is alarmism.”

    Opinion = fact.

    My opinion is that -1’s assertion of “alarmism,” because of the facile nature of his/her reasoning, despite his/her intent, functions as a distraction.

    That s/he would persist after it is pointed out, I would suggest, is evidence of intent other than what was stated.

  118. Andrew Dodds says:

    @EyePie –

    As far as US oil sources go – come back when the US stops keeping a fleet or two in the Gulf.

    Regarding energy – take fuel out of the equation and it does indeed become a manufacturing/technology issue, and for good or bad the price of manufactured items does seem to collapse to near-zero nowadays. Unlike things like fuel, food or land. Turn the energy supply from fuel based to manufacturing based and the price can go down. Thermodynamics does not really come into it (unless EROEI is problematic or your total energy use is hitting some very, very high limits)

  119. It is well understood that the wind drag of the Himalayas and other large mountain ranges are enough to slow down the Earth’s rotation rate. Remember that friction not only can heat but slow things down in the context of conservation of angular momentum.

    “The two types of El‐Niño and their impacts on the length of day” — http://hal.archives-ouvertes.fr/hal-01087222/document

    Surface drag has to be taken into account along with the other thermodynamic variables to do accurate book-keeping of the free energy of the earth. I am inclined to think that the long term variations in the temperature are correlated with the Length-of-Day changes, and the measurements substantiate this. Slight angular momentum changes can cause sloshing of the oceans (remember inertia and conservation of angular momentum) and therefore exposure of deeper colder water to the surface. Not forgetting the wind driven windward-leeward height differential.

    What sends all this in an unpredictable motion? The key is likely in understanding what causes the jittery 2.33 year quasi-biennial oscillation in the stratospheric winds. What kind of weird solar annual influenced heat engine cycle is that?

    Put the geophysics and free-energy thermodynamics together and this will account for temperature variations IMO. And then you can explain to Andrew Revkin of the NYT the origin of the inexplicable temperature wiggles that he keeps tweeting about

  120. -1=e^ipi says:

    @ Joshua –

    I was responding to Willard who asked me to respond to a paragraph that contained “the potential for runaway warming”. Perhaps you should go back and read Willard’s post for better understanding of the context.

    @ Jospeh –

    Yes there is uncertainty and it should be acknowledged and taken into account. You can use risk analysis in a CBA. Of course trying to reduce uncertainty of various parameters (though better research in climate science) helps.

  121. -1=e^ipi says:

    Typo. I meant through not through in my last post.

  122. BBD says:

    And we’re back to talking about ‘alarmism’ again. What a surprise.

  123. verytallguy says:

    ATTP,

    that – in a simple sense – could suggest that the heat engine should become more efficient.

    Absolutely. Both hotter surface and colder TOA = more efficient.

  124. Willard says:

    > Because the arguments many give to justify mitigation policy take the same form as Pascal’s wager.

    That “many” give these “arguments” does not explain why you:

    – choose to peddle unspecified “many” and “arguments” here;
    – associate these “many” and these “arguments” with what is being said here;
    – keep talking about alarmism and Pascal’s Wager when you prefer CBA;
    – dismiss Nordhaus as “mostly opinion” whence it’s supported by CBA and basic risk analysis.

    Unless you studied Pascal’s Wager and the precaution principle, Minus One, you might be surprised where this leads. Infinity is a big concept, so big in fact only Grrrowth may approximate it.

    TL;DR – http://en.wikipedia.org/wiki/Argument_from_fallacy

  125. Willard says:

    > I would suggest that going on about a run-away greenhouse effect as a significant possibility is alarmism.

    Then why are you the only one who mentioned “run-away greenhouse effect” on this thread, Minus One?

    [Chill, W. -W].

  126. Brandon Gates says:

    -1=e^ipi,

    I don’t have the ultimate definition of extreme weather, but any useful definition should satisfy the transitive property and not be based on some arbitrary point in the past.

    I’m not looking for an ultimate definition. A useful one would suffice. I’ll be particularly interested to see what non-arbitrary reference point you use for the baseline.

  127. Brandon Gates says:

    ATTP,

    I think I had assumed that lapse rate feedback meant that the cool reservoir (upper atmosphere) warmed more than the hot, but as you point out that doesn’t necessarily make sense since the radiative temperature remains fixed at 255K.

    I think it does make sense. Agan, I’m just going to parrot what I think I understand about what I’ve read. So lapse rate feedback can be positive or negative. A negative feedback means that a given air parcel will need to rise higher for the same degree of cooling. None of the KE to raise that parcel can come from the additional entropy due to latent heat prior to saturation point, by definition, it can only come from, or only mostly come from, the constant solar entropy addtion. But the wv in the parcel itself is out.

    I think the argument further goes that lapse rate feedback is more negative in the tropics than at higher latitudes. So saturation points will increasingly favor lateral movement poleward, not vertical. It seems a very elegant explanation. I want it to be correct.

  128. VTG’s and Nick’s comments have made me realise that there’s something else that confuses me about this atmospheric heat engine idea. In an idealised heat engine, you take energy from a warm reservoir, you do some work (kinetic energy), and the remaining energy is deposited in a cool reservoir. The efficiency of the engine then depends on the ratio of the temperatures of the warm and cool reservoirs. What’s not, typically, discussed is what happens to the kinetic energy. Presumably it is dissipated somewhere, but that doesn’t matter for the efficiency of the engine.

    In our atmosphere, however, the kinetic energy that drives storms has to be dissipated somewhere, turned into heat, and lost into space. This makes me think that somehow you have a heat engine in which you also have to dissipate the kinetic energy in one of the reservoirs too.

    Having written this, I’m not sure it’s actually all that relevant, but it does confuse me somewhat.

  129. Brandon,
    I’m going to have to think about you’ve said, because I think I’m just getting more and more confused 🙂

  130. Brandon Gates says:

    ATTP, yes, storms. Condensation happens which then puts the latent heat to work, entropy leaves the system radiatively.

  131. verytallguy says:

    ATTP,

    I had the same thought too; but also that the cold reservoir is really deep space at 4K or whatever, as the heat loss from TOA is radiative. I think it is the temperature gradient surface to TOA which is relevant here rather than equator to pole.

    All of which should convince me that I’m out of my depth, except that I once took a class so know I’m much better informed than any actual scientists studying this sort of thing 😉

  132. Brandon Gates says:

    ATTP, PS I could be just as confused as you. But it feels like it’s clearing up for me.

  133. Michael 2 says:

    Wolfram Alpha confirms this interesting relationship that “e” and “pi” can be related to each other producing an integer. I understand the significance of pi but I don’t remember the derivation of “e”, the root of natural logarithms. Who would have thought that it relates to pi in any way.

    At any rate, Wolfram Alpha returns “true” so I suppose it is a very exotic way of creating an alias for a handle of “true”.

  134. A couple of things are essential for the atmospheric heat engine.

    1) Heat must be added at locations, where the temperature of the atmosphere is higher and removed from cooler atmosphere. That combination leads to the addition of free energy to the atmosphere, and only free energy can drive a heat engine.

    2) Availability of free energy does not guarantee that the heat engine will work, as it’s possible that the efficiency of the engine is essentially zero. The atmosphere can have a significantly non-zero efficiency only, when the cold side is located at a higher altitude than the hot side, The surface temperature difference between the tropic and the high latitudes is not enough to keep the engine running with a significant efficiency.

    The main heat engine that runs the large scale circulation is in the Hadley cells. The get their energy from the combination of air heated at the surface going up and air cooled in the upper troposphere coming down. The Hadley circulation is powerful enough to force the Ferrel cells to run in the direction that consumes work as well as all the other main circulation. (The cells are coupled by the jet stream.)

    The atmospheric heat engine is not efficient, it’s efficiency is only a few percent. Many different factors contribute to its low efficiency. Therefore it’s impossible to conclude much from the changes in one of the factors.

    From the numerous processes that dissipate the work produced by the atmospheric heat engine one of the easiest to estimate is related to precipitation. Water is carried up as vapor. Much of that condenses and falls down as liquid droplets or ice. All the potential energy of that water is lost from the power generated by the heat engine, and even more as the rain falls usually in regions, where air is rising. This is, however, only a small fraction of the total dissipation.

  135. Michael 2 says:

    verytallguy says: “I once took a class so know I’m much better informed than any actual scientists studying this sort of thing”

    And I read this blog which is practically the equivalent of earning a degree; or at least picking up some homework assignments now and then.

  136. Michael 2 says:

    Minus One says “My understanding is that the GDP elasticity of population for Canada is ~ 0.06”

    How many Canadians know or care; or use logic in their everyday lives? I’m really pretty sure they would not like it, depending of course on what Americans go north and where they go. Already citizens of Seattle go to Vancouver and culturally they are quite similar. Likewise citizens of northern Minnesota go to the Boundary Waters canoe area which extends well into Canada.

    But a bunch of Arizona Republicans going to Toronto would probably not be very welcome (nor, for that matter, are the Arizonans going to want to go to Toronto — by the way, leave your guns at the border, there’s no Second Amendment in Canada. In fact, there’s not even a Constitution!).

  137. Willard says:

    I dare you MOOC MikeR, Very Tall.

  138. BBD says:

    M2

    Who would have thought that it relates to pi in any way.

    More here.

  139. Michael 2 says:

    Victor writes “climate scientists are not climate alarmists”

    Some are, some aren’t. Since I do not know most of them, I suspect most are not. The ones I know are the ones that make themselves known, ie, raising an alarm. Of them, how many are actually afraid for the future is a thing I cannot discern (as compared to how many are just squeezing the teat of government grants).

  140. verytallguy says:

    Pekka, thanks.

    So what, to a first estimate, is the expected impact of a warming climate on the Hadley cells?

    I would presume the larger temperature difference surface to tropopause should increase the circulation if that temperature difference is what drives the circulation?

    But I’m sure I’ve read the opposite…

  141. Michael 2 says:

    verytallguy writes “If we consider the source temperature to be the surface temperature in the topics, is the sink temperature better thought of as the – deep space temperature (IR to space)?
    – tropopause temperature? – pole temperature?”

    I propose a better metaphor is a modern steam turbine which consists of a daisy chain of sources and sinks; each sink is also the source for the next stage which operates at a lower temperature and pressure.

    The first stage atmospheric heat engine doesn’t really count but is being ignored; that’s the stage that creates the “fuel” — water vapor. This is the stage that consumes a great deal of solar energy and produces water vapor.

    The next stage is condensation. Where and why it happens depends on geography mostly (IMO). But the “engine” metaphor tends to require a self-contained cell of some kind as without a container you also have no barrier between source and sink, no engine, no useful work.

    So a rising column of air is doing work (rising), and is pumped along by its own heat-generation relative to immediately adjacent air that is sinking to replace the uptake.

    There’s no need to consider deep space at this stage.

    So, what about that cooler air adjacent to the rising plume? How did it get colder? Well, it did radiate into space, the product of an earlier thermal plume. BUT it doesn’t come down where it went up because the earth rotates under the air and Coriolis forces bend its northward (and southward) outward flow after, and while, radiating heat into space.

    But the stage of radiating heat into space isn’t really part of the engine itself; it is mere preparation to become part of the engine, the cold sink for the engine is adjacent cooler air.

    So ATTP has a good understanding, it is a difference in air temperature that powers the engine, not deep space. But deep space is merely the way the cold sink is “regenerated” once heated by the “engine”.

    There’s rather more to it; such things as the plume itself cannot radiate into space if it still contains condensation — the water droplets are opaque to IR (and reflective to visible) and also at a much lower temperature, having given up their heat to atmosphere. Only the outer surface of the cloud can radiate, also any CO2 can radiate; warm air by itself neither absorbs radiation nor radiates itself.

    Because of that it is really very complicated; CO2’s effect at the surface is to heat the surface, but its effect at high altitude is to enhance radiation — increasing the vertical thermal gradient while other forces are working to reduce the vertical thermal gradient. May the best molecule win!

  142. anoilman says:

    -1=e^ipi I love the reference to using irrational numbers. Its somehow fitting with you.

    “If you asked the public what extreme weather means, they would say things like floods, droughts, blizzards, hurricanes, tornadoes etc.”

    Yes.

    And we have already tied floods, droughts, and blizzards to Global Warming. The Jet Stream is meandering because of the lower thermal gradient from the poles to the equator. This causes long early springs in places, and late long winter storms. Its meandering so its kinda random.

    The meandering Jet Stream has also been locked in place (so not meandering) over California causing a drought and driving up food prices. In Canada, we’ve already seen prices going up.

    Warmer climates moving north have decimated logging towns in BC due to Pine Beetles. It seems poor form to support financially liquidating people because you think paying 35 cents a Kwh is ruinous. (solar on battery in Canada, home installed)

    But for a guy arguing that its not a concern to deal with Global Warming, I have turn this back to you.

    Since you are a pro-terraformer wanting to alter the Earth’s bio sphere, what are your intended goals? What is your plan? How much damage is the right amount for you? What kind of damage? What is the amount of deaths you wish to achieve?

    As an engineer, I can tell you that this kind of project fails and ends in a law suit. I am indeed alarmed that this project isn’t defined somewhere.

  143. Joseph says:

    Michael what you do think makes a scientist an alarmist? Is ATTP an alarmist?

  144. VTG,
    I looked at the paper only after I wrote my previous comment. The paper approaches the questions in a way that’s not easy to follow without expertize in the same specialties the authors have, but they seem to make comments similar to what i wrote as the last paragraph of my previous comment.

    I have on a couple of earlier occasions looked at the nature of the atmospheric heat engine and written comments on that at Climate Etc. At that time I tried to find more on what has been written on the mechanisms in the scientific literature, but could not find much. Perhaps some of the references of the Laliberté et al paper will help in that.

    The paper emphasizes the dissipative losses related to precipitation. They seem to think that these losses are larger than the addition to free energy production from the increased GHE. That’s quite possible. Whether the models that they use are capable of capturing all relevant changes is impossible for me to tell.

  145. Steve Bloom says:

    My inexpert and somewhat vague understanding is that the Hadley circulation weakens with warming primarily due to expansion of the tropics (a little up and a lot poleward), hotter air wanting to do what hotter air does. I have no idea what the numbers are, but it seems to me that the energy required to keep it in that expanded state must be very large. But at the same time, the rate of circulation (i.e. winds) decreases.

    The effect of polar amplification is interesting. It too implies a weakening of heat transport due to a declining temperature difference between equator and poles, but countervailing that is the need for a large increase in heat transport (known to have to happen due to direct evidence for a much warmer Arctic during the Pliocene). Overall this is not at all intuitive for me, nor as far as I can tell anyone else since the mechanism for the heat transport isn’t clear. But because of the general expectation for stronger albeit less frequent storms as the planet warms, the tropical cyclone mechanism proposed by Emanuel, Fedorov and Brierley et al. (the latter is co-author on a new paper on the topic that may shed further light) is very appealing. Sandy and Nuri might be harbingers, but it’s really too early to expect observations to shed clear light on the subject.

    Note that the GCMs continue to hit a brick wall on getting the needed polar amplification. Ballantyne et al. (2012 IIRC) managed to do a Pliocene-like climate at equilibrium with a simpler model, which is some progress, but I’ve been watching for some sort of fundamental breakthrough on this and have yet to see one.

    Interesting times.

  146. Joseph,

    Is ATTP an alarmist?

    People keep telling me that I am 😀

  147. Steve Bloom says:

    OT: These comments from U.S. coal executives are illuminating, in part because they’re public, in part because they verge on foaming at the mouth, and in part because these are some of the folks who’ve been orchestrating the denial campaign these past years. Note in particular the claim that science is on their side. .

  148. Nick Stokes says:

    VTG
    “If we consider the source temperature to be the surface temperature in the topics, is the sink temperature better thought of as the
    – deep space temperature (IR to space)?
    – tropopause temperature?
    – pole temperature?”

    I think tropopause. In a Carnot cycle, the essential thing about the heat sink is that the heat disappears into it at that temperature. It doesn’t really matter what happens afterward. Tropopause gas is the coldest thing on Earth that can act actually participate in heat exchange at signficant rate.

  149. Steve,

    I don’t think that the polar amplification is quantitatively significant for these considerations. I would take it as a almost totally unrelated issue.

    I raise another point from the comment article of Olivier M. Paulus on the Laliberté article in the same issue of Science. Paulus writes:

    .. Second, water mostly evaporates in unsaturated air, and this evaporation is thus thermodynamically irreversible. Such irreversibility reduces the work produced by a heat engine compared to a Carnot cycle.

    I think that the statement is misleading. In a sense it is true, but the real effect is included in the actual temperature. Without the effect, the temperature would get higher and that would increase efficiency, but when the temperature is taken as given, I don’t think that the effect is true. In typical analysis the temperatures are taken as the observed ones and thus given. For that reason the comment seems to be misleading.

    Furthermore the actual evaporation does not take place far from saturation. Thus the entropy increase does not occur at that stage, but later, when the moist air is mixed with less moist.

  150. Nick,
    I agree. The relevant temperature is the temperature of the air at the point of heat exchange. That applies both to heating and to heat loss by radiation.

    Cooling of air at low altitude does not contribute much to the power of the heat engine, because cold air at low altitude has no way of converting it’s relative coldness to a work. Cooling air at high altitude makes it descend (or makes it at least easier to force it descend), and that adds to the generation of work.

  151. This issue is also related to another issue discussed recently on this site: What constraints evaporation?.

    In both cases a larger fraction of heat is transferred as latent heat in a warmer case. Thus the same amount of total energy transfer involves smaller mass flows (less circulation). A larger fraction of the energy is released to the atmosphere as sensible heat at higher altitude through condensation. At surface some constraints can be derived to linked energy fluxes there. The top of the atmospheric boundary layer is another place where constraints may apply.

  152. izen says:

    I too would welcome a clearer, or better explanation of this research, both the claims it is making, and the implications of that for the actual impacts on human life at ground level.

    So far I think I get that warming the atmosphere increases its energy carrying capacity by increasing the water vapor content. Therefore the same amount of energy can be transported polward with lower volumes and velocity of air movement. As most storms/high winds are the emergent turbulence from such air flows, there will be fewer and less intense storms because the driving air flow is reduced because it can distribute the heat to the sinks (pole/tropopause) more effectively.
    As an additional effect of the greater transport efficiency, the equator-pole temperature gradient also decreases because the greater energy transfer capability of the atmosphere driven by the increased surface temperatures can distribute the energy by phase changes of water more effectively. And without the large thermal gradient between equator and pole that exists at present.

    This seems to be confirmed by the paleoclimate data that shows warmer periods had ice-free poles, or at least arctic, with temperate climate zones extended inside the arctic circle. Even the S pole seems to have melted during the Pliocene ~4 million BPE.

    I am sure I am missing a lot, but that seems to be the Heat-Engine Thermodynamic processes this paper is referencing. Perhaps others with a better grasp can point out all the errors!

    But I am not sure the deductions made about the weather, the frequency and intensity of storms, are of much relevance. As Pielke keeps telling us, storm damage, or weather extreme damage is only partly correlated with weather intensity. The wealth, resilience and adaptive capacity of the population and human infrastructure hit by a storm is as much , if not more a factor in extreme weather damage than the relative intensity of the event.
    Although YMMV on that CBA.

    If we could be certain that the ONLY impact of warmer air carrying more energy was fewer, and less intense storms, but perhaps with the occasional, rare mega storm, then perhaps it would be justified to see that as ‘good’ news about the effects of AGW, physics refuting the alarmists.
    But that seems… unrealistically Panglossian.

    ATTP may be ‘alarmist’ about the risk of >35degC wet bulb temperatures, a warmer climate with warmer poles because of WV heat transfer will be able to shed the extra surface energy from the GHG effect. Perhaps avoiding the tropical dead zones that such temperature imply.
    But that does imply the Greenland ice-cap and much of the W Antarctic sheets will go. That alters sea level rather profoundly, it is also likely to have significant impacts on where and when rainfall occurs.
    Adapting is neither easy or cheap for water based agriculture and coastal infrastructure.
    There are likely to be rather more profound effects than those of us who dislike the winter cold enjoying a stable year-round Cote-D’Azur or California climate.
    If they do, it may well come with droughts.

    I agree with vtg about this, I would like to grasp more of the thermodynamics, and how it is applied. That might help tease out what are, and are not credible deductions about the climate, and weather, that human cities and agriculture may experience if the analysis is correct.

    I would politely remark that the poster with the transcendent, complex and irrational screen-name has probably been the least helpful in elucidating the science, and implications of this. Their first contribution seemed to be a science ‘gotcha’ aimed at the mainstream concern over climate change. Further comments have done little to show any interest in this research beyond that.

    One final complication, I had thought that around half the energy transport from Equator to pole was by the horizontal movement of water in the oceans. How does a diminishment of wind driven currents affect this?

  153. verytallguy says:

    Nick, Pekka,

    re tropopause as heat sink temperature. Yes, after thinking that’s clearly correct. Thank you.

  154. Thanks for writing this, and saving me the effort of reading it. What you wrote was about what I was expecting.

    FWIW, I think this thread is too contaminated by off-topic stuff. I think you need to clamp down on the non-science (because your commentators can’t resist being trolled, as they should); having yet another round of the alarmism wars is tedious. How about just putting a note on some pure-science posts, like this, to say that OT comments will be deleted and OT portions of otherwise interesting comments, ditto? Oh, and doing it :-).

  155. WMC,

    Oh, and doing it :-).

    I actually agree with your suggestion, but – believe it or not – I delete a fair number already. Probably do need to do more, though 🙂

    Oh, and there is the whole “other work to do and not getting paid for this issue”, but your point is well made, nonetheless.

  156. izen says:

    @-verytallguy
    “re tropopause as heat sink temperature. Yes, after thinking that’s clearly correct. Thank you.”

    Yes, but it is HOW the surface energy gets there that matters. As always ‘Lucy’ looks after the details..!
    perhaps this paper is directed at those pathways.

  157. Actually this paper is mainly about observations, and only rather superficially on the mechanisms. Observation based data (from reanalysis) is compared with model calculations, but that’s not enough to tell, why things are as they are.

  158. > FWIW, I think this thread is too contaminated by off-topic stuff.

    Why not start with Dr. Connolley’s comment, AT, since playing the ref’s against the house rulz?

    Then you could delete this one too, of course.

  159. Joshua says:

    I know it’s off topic, and thus might upset WC, but I read this:

    ==> “Murray was much more pointed in his remarks, calling Obama “the greatest enemy of my lifetime”

    And wanted to make sure that -1 knows I’m here if he needs me, you know, in case he gets overwhelmed by Murray’s alarmism.

  160. izen says:

    @-Pekka Pirilä
    “Actually this paper is mainly about observations, and only rather superficially on the mechanisms. Observation based data (from reanalysis) is compared with model calculations”

    So this might be relevant, if only because of possible discrepancies between model/observed lapse rates over short/long timescales?

    http://www.gfdl.noaa.gov/blog/isaac-held/2015/01/20/55-tropical-tropospheric-warming-revisited-part-2/

  161. Steve Bloom says:

    “your commentators can’t resist”

    Indeed, nor can Anders himself.

  162. Steve Bloom says:

    Careful, Willard, that train of logic might end with Anders vanishing in a puff of smoke.

  163. Brandon Gates says:

    Having slept on my previous comments, thinking about feedback from Nick and ATTP, and waking to read the comments by Pekka and VTG I realize I’m definitely confused and out of my depth but still seduced by this paper. Which is discomforting. So. I’ll not stump for this paper in my travels, but not throw it under the bus either.

    Anders, again, thank you for posting this. Distractions aside this has been a very interesting thread.

  164. Michael 2 says:

    BBD wrote “M2 Who would have thought that it relates to pi in any way. More here.”

    Thanks for the link. I’m a little embarassed to have forgotten that e involves sin and cos which are of course related to pi. That’s one thing about my profession, I don’t need calculus but I *like* calculus. It can do magical things if you need magical things done.

  165. Nick Stokes says:

    I’ve been thinking more about Hadley Cells and Carnot cycles. I wrote a post here. Incidentally, the paper is available here.

  166. deminthon says:

    The ones I know are the ones that make themselves known, ie, raising an alarm.

    a) Those are not the same thing at all.

    b) It’s good to raise an alarm about something alarming. If that’s all that “alarmist” means, then being an “alarmist” is a good thing. Of course, that’s not what the word is intended to convey.

    Of them, how many are actually afraid for the future is a thing I cannot discern (as compared to how many are just squeezing the teat of government grants).

    Perhaps you are missing vital information needed to discern it. The correct answer is 100% (as compared to 0%).

  167. deminthon says:

    Trusting an authority and then taking action based on your belief is a reasonable definition of “religion”

    No, actually, it’s not. Rather. it’s an example of a fallacy of affirmation of the consequent.

    More to the point, when “doing something about it” becomes imposing that action on non-believers, then it resembles both Christianity and Islam.

    No, it resembles a law-based society.

    Note also the parallel — the actual scientists doing climate research are seldom the public authorities. Al Gore, for instance, has a degree in political science.

    Al Gore is neither a scientist nor a public authority. He did however communicate, fairly accurately, the work of “the actual scientists doing climate research” and their concerns.

  168. -1=e^ipi says:

    I have thought more about this and I want to retract my claim that a reduction in the surface-tropopause temperature gradient suggests a reduction in the frequency/intensity of certain climate phenomena (although I still stand by my claim with respect to the polar-equatorial temperature gradient). My claim was naive and I apologize (although claims like ‘more heat -> more extreme weather events’ or ‘more water vapour -> more heat transport -> more extreme weather events’ are also naive).

    Rather, ask yourself why the lapse rate is the way it is. My simplistic understanding (please correct me if I am wrong) is that the lapse rate can be approximated to be on the edge of adiabatic stability (because if it were not stable, then various weather events such as storms and hurricanes would take place until the lapse rate approaches adiabatic stability). At the surface, the air is at roughly 75% humidity. If an air parcel moves upwards adiabatically from the surface, it will cool with the dry lapse rate of 9.8 C/km. At a certain point, the air reaches saturation (because colder air cannot contain as much water vapour, according to the clausius-clapeyron relation), at which point as the water vapour moves upward adiabatically some of the water vapour will condense, releasing latent heat. This causes the lapse rate to drop to the wet lapse rate of approximately 2/3 the dry lapse rate. However, the wet lapse rate is not constant and it is lower for air of higher temperature (since that air contains more water vapour due to the clausius-clapeyron relation).

    So the temperature difference between the surface and the tropopause decreases as the Earth warms because the wet lapse rate is smaller for warmer air since warmer air contains more water vapour. Previously I was under the impression that the reduction of the lapse rate was primarily due to the upper troposphere becoming more opaque to long wave radiation. But as long as the surface tends to get more energy from the sun than the upper troposphere, the lapse rate should tend towards the edge of adiabatic stability.

    So perhaps when thinking about the creation of storms / hurricanes, it should be thought of as a result of adiabatic instability. And the sun is the primary cause of that instability since the atmosphere is relatively transparent to sun light, so the sun warms the surface more than the upper troposphere, creating adiabatic instability (which must be corrected for by storms and other weather events).

    So take two scenarios: one where the atmosphere is warm and at the edge of adiabatic instability, an one where the atmosphere is cool and at the edge of adiabatic instability. Now lets say that the sun comes along and heats a small parcel of air by 1 Joule for each scenario. Then adiabatic instability will be created and that parcel of air will rise adiabatically to the troposphere. When the air gets to the top, it has cooled due to rising (depending on the lapse rate) and it should have 1 J more of heat that a comparable parcel at the tropopause. So this means that there is 1J to perform work in both cases. So the change in the lapse rate and the increase in water vapour due to warming basically cancel each other out exactly.

    So many climate phenomena such as storms are driven by adiabatic instability that are caused by the sun heating the surface more than the upper troposphere since the atmosphere is relatively transparent to sunlight. And the places where you have the most direct sunlight (the tropics) have the most adiabatic instability, so have the most intense and frequent storms. So even if global warming hypothetically caused Britain to have tropical temperatures, there would still not be hurricanes being created at that latitude because the cause of adiabatic instability (the sun) is still the same. If anything, the fact that a warmer earth will have more cloud cover (reducing sunlight reaching the surface) and the fact that a warmer earth will have a more opaque upper troposphere will reduce the ‘uneven’ heating caused by the sun, which will reduce the amount of adiabatic instability, and will therefore reduce the frequency (and maybe intensity) of various climate phenomena such as storms and hurricanes.

  169. -1=e^ipi says:

    My comment in the last post that there would be 1J of energy to perform work in both cases, is not correct because a the heat engine will not have anywhere near 100% efficiency in either case. If we take the efficiency to be 1 – Tc/Th (perfect carnot engine efficiency), then the warmer scenario will have a lower efficiency since saturated air of higher temperature has a higher heat capacity (thus the temperature difference will be lower) and also increasing Tc and Th by the same amount reduces efficiency.

  170. -1=e^ipi says:

    I was going to comment earlier on how the reduction in equator-polar temperature gradient affects the jetstreams, but was derailed. A short summary is basically as follows:

    – The poleward height gradient of the tropopause is proportional to the latitudinal temperature gradient.
    – The rate at which air at the tropopause accelerates poleward is proportional to the poleward height gradient (actually, sine of the arctan of the gradient, but the gradient is small).
    – The speed at which air at the tropopause moves poleward is proportional to the square-root of the poleward acceleration (since the force of air resistance is roughly proportional to the square of the speed).
    – The zonal speed of a jetstream is proportional to the speed at which air at the top of the tropopause moves poleward at the latitude of the jetstream.
    – Put these together suggests that the speed of the jetstream is proportional to the square-root of the poleward temperature gradient (at the latitude of the jetstream).

    – The properties of a jetstream can be obtained by looking at conservation of potential vorticity (which can be obtained from conservation of angular momentum).
    – By considering forced standing waves that result from the conservation of potential vorticity, one can show that the wavelength of the jetstream is roughly proportional to the square root of the zonal velocity, that the amplitude of the jetstream is roughly proportional to the inverse of the square root of the zonal velocity and that the frequency of resonant phenomena of the jetstream is roughly proportional to the zonal velocity to the power of -1.5.
    – By considering plane-wave solutions that result from the conservation of potential vorticity, one can show that the group velocity of the jetstream is proportional to the zonal velocity.

    Put this together and you get that the amplitude of a jetstream is proportional to the temperature gradient to the power of -0.25, the wavelength of a jetstream is proportional to the temperature gradient to the power of 0.25, the frequency of resonant phenomena of a jetstream is proportional to the temperature gradient to the power of -0.75, and the group velocity is proportional to the square root of the temperature gradient.

    The northern polar jetstream is probably of the most interest here, since the tropical jet streams are weaker and the southern polar jet stream does not have as much topological features to generate forced Rossby waves (cause it’s mostly ocean at that latitude).

    If one assumes that the global average temperature at 40 N (which is ~15 C) represents the Northern Ferrel Cell, that the global average temperature at 70 N (which is ~1.5 C), that the temperature as a function of latitude is roughly linear between these two latitudes, and assume a polar amplification factor of 2.5, then one can approximate the expected change in some of the properties in the jetstream for a given warming. For example, using a temperature increase of 3C for global temperatures and the assumption that polar temperatures will decay roughly exponentially to global temperatures (since polar temperatures exceeding global temperatures would not make any sense) one would get that the polar temperatures increase by ~8.33 C. This corresponds to a reduction in the zonal velocity & group velocity of the northern polar jetstream by 15.4%, an increase in the amplitude of the northern polar jetstream by 18.1%, and an increase in the frequency of resonant phenomena of the northern polar jetstream by 64.9%.

  171. -1=e^ipi says:

    woops, I made a mistake in the last part of my last post (forgot to take a square root). I should have written:

    This corresponds to a reduction in the zonal velocity & group velocity of the northern polar jetstream by 15.4%, a reduction in the wavelength of the northern polar jetstream by 8.0%, an increase in the amplitude of the northern polar jetstream by 9.7%, and an increase in the frequency of resonant phenomena by 28.4%.

  172. pbjamm says:

    -1 “woops, I made a mistake”

    You should have stopped there.

  173. -1=e^ipi says:

    @ pbjamm – I thank you for your very insightful input. Thank you very much for your attempt to bring the thread discussion back to science, rather than try to derail it.

  174. Michael 2 says:

    deminthon says (referencing my comment: More to the point, when “doing something about it” becomes imposing that action on non-believers, then it resembles both Christianity and Islam.)

    “No, it resembles a law-based society.”

    Of course; and who makes the laws? Christians and Muslims, where they are dominant that is.

    Law is whatever people say it is. But what do the people say? Most will say what they are told to say (or else pay some sort of penalty in this life and the one to come). That is true on many fronts.

    When climate science reaches the public, all 7 billion of them, it’s no longer science. It’s being told something not visible evident which they are to trust because someone in authority, self appointed (or by a very small club such as the college of cardinals) quite often, SAYS so — whether that authority is the Pope or the director of the IPCC.

    How exactly did Pachauri become director?
    http://en.wikipedia.org/wiki/Rajendra_K._Pachauri

    “On 20 April 2002, Pachauri was elected Chairman of the United Nations established Intergovernmental Panel on Climate Change.”

    By whom?

    It’s a bit vague. A little over 100 votes are cast, one per nation and I think NGO’s also get a vote. How a nation chooses its delegate is unclear but possibly interesting, doubtless more political than scientific. Obviously this scheme heavily weights in favor of tiny developing nations hence the UN’s goal of 100 billion dollars per year for those same tiny developing nations.

    Book: “Carbon Politics and the Failure of the Kyoto Protocol” goes into it in great detail, excerpts of which can be seen on Google Books.

    Additional reading suggests that the executive branch of the United States (the President thereof) chooses the delegates, making USA participation heavily dependent on the party in power. So it doesn’t matter so much WHO is the delegate but how appointed.

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