Forcings and feedbacks

After my lengthy exchange with Roger Pielke Sr, I thought I might write a quick post about forcings and feedbacks. I thought I might also comment on this tweet from Roger

I’m really not sure quite why this is a “Wow” thing to have said. The only thing I probably regret saying is “I don’t think” at the beginning. They very obviously are not the same thing. The units are different, and one is a vector (force), the other a scalar (radiative forcing). For clarity, a radiative forcing is

In climate science, radiative forcing or climate forcing, is defined as the difference of insolation (sunlight) absorbed by the Earth and energy radiated back to space.

In physics, a force is

a force is any interaction which tends to change the motion of an object.

Consider Newton’s laws of motion if you want a more extensive discussion of the concept of a force. I can see why climate science uses a forcing/feedback paradigm (a forcing pushes the system out of energy balance, and the feedbacks act to return it to energy balance) but that doesn’t mean that they’re exactly equivalent.

Okay, back to forcings and feebacks. A forcing is some external influence that causes, as pointed out above, a change in the energy balance of the system. For example, if we are in energy balance and there is then a change in forcing of \Delta F, then if \Delta F is positive, it means – if nothing else changes – that we’ve moved into a state where we are now accruing energy at a rate of \Delta F Joules per square metre per second. If \Delta F is negative, then we will be losing energy. If the initial energy imbalance was not zero, then \Delta F tells us how much it has changed.

If we are out of energy balance, then that we are accruing – or losing – energy means that we will either warm, or cool. The change in temperature then causes a feedback response, and these are normally quantified with respect to the change in surface temperature (\Delta T). Examples of feedbacks are the Planck response (negative), water vapour (positive), lapse rate (negative), and clouds (probably positive). The units of feedbacks are Wm^{-2}K^{-1}, so it tells us what impact that feedback would have on our energy balance if the temperature changed by 1K. If a feedback is positive, it causes additional warming/cooling. If it is negative, it acts to drive us back to energy balance.

Given that our climate is long-term stable, overall feedbacks (including the Planck response) are clearly negative. If not, a small change in radiative forcing would cause runaway warming; it clearly does not. The more interesting question is whether or not the feedbacks other than the Planck response are positive or negative. Our current understanding is that these feedbacks (water vapour, lapse rate, clouds) are overall positive. This means that we expect a change in radiative forcing to be amplified by these feedbacks and for the overall warming to be larger (by a factor of 2 – 3) than would be the case in the absence of these feedbacks.

To put this into a slightly more formal context, consider a situation where – at time t_0 – we have a planetary energy imbalance of N_0. Now consider a later time, t, where there has been a change in forcing of \Delta F, and a change in temperature of \Delta T. The planetary energy imbalance, N_t, at t, will be

N_t = N_0 + \Delta F - 4 \epsilon \sigma T^3 \Delta T + W_{\rm feed} \Delta T,

where, the second term on the right-hand side is the Planck response (and includes the emissivity, \epsilon \sim 0.6, of the atmosphere), and the final term is all the other feedbacks. We can rewrite this as

N_t - N_0 = \Delta N = \Delta F - 4 \epsilon \sigma T^3 \Delta T + W_{\rm feed} \Delta T.

So, the forcings and feedbacks are both determined as changes relative to some earlier time (t = t_0, when the planetary energy imbalance was N_0) and they, together, tells us how the planetary energy imbalance has changed between time t_0 and t. It is, however, a fairly simple formalism and the system is clearly much more complex than this simple formalism can – alone – indicate. However, it is still a useful way to quantify – in a globally averaged sense – how we might respond to changes in forcings, or – if we already have some information – how we have responded to known changes in forcings. We can, essentially, use it to estimate our climate’s sensitivity to changes in radiative forcings.

Anyway, I hope that roughly clarifies the situation with regards to forcings and feedbacks. If anyone has anything to add, or would like to correct something, feel free to do so; there are some complexities that I’ve ignored. I’ll also add that some may be aware – via Twitter – that I’m not very happy with the manner in which Roger has chosen to represent our discussion. However, since this is not WUWT, I’m not really interested in some kind of lengthy discussion about Roger’s behaviour. He can own it, as far as I’m concerned. The only reason I’m saying this is to simply warn commenters that I’ll aim to moderate anything that I regard as non-constructive.

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204 Responses to Forcings and feedbacks

  1. I guess to a lay person like me ‘forcings’ and ‘force’ have similarities, in that we think of them both in general terms as ‘pushes’ or ‘pulls’. However we also know that in disciplines such as physics and chemistry words are often given very specific meanings. Such differences in interpretation are often the source of confusion when a wide audience is addressed. However, Roger Snr is a physicist is he not, and he must know you, aTTP, are also; so just what did he mean by ‘Wow’? And then why did he just leave it hanging?

  2. john,
    I’m confused too. I had first thought that maybe his “Wow” was because I wasn’t more definite, but it wasn’t me who brought up the comparison with a force in physics. Anyway, I’m really keen to not have this degenerate into a WUWT-like comment thread, so I’m going to refrain from guessing someone’s motives.

  3. angech2014 says:

    This means that we expect a change in radiative forcing to be amplified by these feedbacks and for the overall warming to be larger (by a factor of 2 – 3) than would be the case in the absence of these feedbacks.
    these feedbacks (water vapour, lapse rate, clouds) are overall positive.
    The factor of 2-3 interests me.
    You are using IPCC assessments of the amount of the feedbacks to derive this degree of positive response.
    Yet you state
    “Given that our climate is long-term stable, overall feedbacks (including the Planck response) are clearly negative.”
    Seeing we have had periods of much higher CO2 in the very distant past which lasted for millenia should there not have been runaway or at least extremely high temperatures back there with the
    same feedbacks giving 2-3 times amplification?
    No one has mentioned extremely high temperatures during those millenia or epochs that I am aware of hence your comment on long term stability.

  4. angech,

    Seeing we have had periods of much higher CO2 in the very distant past which lasted for millenia should there not have been runaway or at least extremely high temperatures back there with the same feedbacks giving 2-3 times amplification?

    Well, no, not really. Firstly, for runaway you need positive feedbacks overall. The Planck response will almost always dominate, so runaway warming is difficult, except in extreme scenarios. You also need to consider all the external forcings. If you consider the period about 500 million years ago, atmospheric CO2 was maybe 7000ppm. Relative to 280ppm, that is a change in forcing of 5.35 \ln (7000/280) = 17Wm^{-2}. If we assume 3.7Wm^{-2} per 1oC, then without feedbacks that would be a warming of 5oC. If we increase this by a factor of 3 we get about 15oC warmer than pre-industry.

    However, solar insolation was maybe 3 – 4% lower during that period than it is today. Roughly, that would reduce solar forcing by about 7Wm^{-2}. This means that the net change in forcing (relative to pre-industry) would be around 10Wm^{-2} which would imply maybe 10oC warmer than it is today. This – as I understand it – is not far off what’s been estimated.

    Of course, albedo would be different, which would have an impact too, but – as I understand it – even these periods when CO2 was much higher than today are consistent with what I’ve presented here.

  5. MikeH says:

    The tactic that Pielke Sr. employed is cheap and well worn.

    “Debating creationists on the topic of evolution is rather like trying to play chess with a pigeon; it knocks the pieces over, craps on the board, and flies back to its flock to claim victory.”

  6. I wonder if the problem is an American/British language-use thing? Americans living in the UK often say it takes them a while to get used to British understatement. When you said “I also don’t think…” any British person knew that what you actually meant was that there was no doubt. Two nations divided by the same language? http://en.wikipedia.org/wiki/Understatement

  7. john,
    Well, yes, possibly. When I say something like “I don’t think it means that” what I’m really saying is “Don’t be stupid, it doesn’t mean that” 🙂

    There’s a great chart showing the difference between UK and US PhD supervisors. I can’t seem to find it anymore.

  8. Joshua says:

    Well, that wasn’t very useful, was it?

    Please delete comment above. I tried to post this:

  9. Joshua,
    Yes, thanks, that’s the one.

  10. cgs says:

    After reading through some of Roger’s comments, especially the one below, I wonder if he is not saying the following:

    1. Both a forcing and a force change the energy of a system. When there is a force imbalance on a mass, it will accelerate. When you accelerate a mass, you change its kinetic energy. The force imbalance leads therefore to a change in the energy of the mass. When all forces sum to zero on a mass, there is not change in the energy of the mass.

    2. When there is a radiative forcing imbalance, there is a change in the energy of the system. When the radiative forcings on a system sum to zero, there is no energy imbalance and the system’s energy will therefore not change..

    I think this, because in the comment below he says:
    We can apply the same use of the concept of force to radiative forcing and feedbacks.

    So he seem to understand these are different concepts. But if the similarity that he is trying to draw is indeed based upon what I wrote above, I am still not clear what advantage is gained. If that is not the similarity that he is trying to draw, then…

    Watt about Roger’s questions?

  11. cgs,
    I’m sure that is roughly what he is suggesting. It’s indeed true that the forcing/feedback paradigm is one in which you consider changes from some kind of equilibrium situation and how these changes then drive the system to a new state of thermal equilibrium. I have no issue with the basic statement

    We can apply the same use of the concept of force to radiative forcing and feedbacks.

    However, none of that invalidates that a forcing in climate science is not equivalent to a force in physics. It’s simply a representation based on a similarity in how one might view these two physical situations. The “Wow” would seem to be an odd way to respond to that basic suggestion.

    One obvious difference between the forcing/feedback paradigm and the basic physics force, is that when you apply a force to an object, there is no automatic feedback response. The object simply accelerates. You need to apply another force in order to bring the object back to a state of rest or to a state of constant velocity. In the climate science scenario, applying a forcing does – as you say – lead to a change in the energy of the system which – unless the heat capacity were infinite – would ultimately always lead to a new state of thermal equilibrium.

  12. cgs says:

    Thanks for the reply. Yes, it is critical to point out the feedback response in the climate system, which is always present, as compared to the pure force where it is not always present. In the force case, that depends upon the potential the mass finds itself in. Gravity acting as a restoring force for a pendulum is one I can think of. In that case, one could end up moving a pendulum mass to a new position if you balance the pushing force with the gravitational response..

    But, I totally agree with your statement:
    However, none of that invalidates that a forcing in climate science is not equivalent to a force in physics. It’s simply a representation based on a similarity in how one might view these two physical situations.

    It seems strange that Roger appears to want to have civil debates, yet some of his actions are not in line with that desire. The use of “Wow”, because of the implications it attaches to the sentence he quoted from you, is one example. Odd indeed.

  13. cgs,
    Thanks, my comment to Roger was really a response to this comment where he said

    You want the radiative imbalance in 2015 and the 2015 radiative forcings and feedbacks.. I would like that too.

    I can see how one can define a radiative imbalance in 2015 – difference between the energy in and the energy out, divided by time. I can’t quite see how one can define a radiative forcing and feedback in 2015, other than as a change relative to some earlier time. This is especially true for feedbacks since they depend on a temperature change, which has to occur over some time interval. Since the feedbacks are typically associated with a change in forcing, it doesn’t make sense to me to try and defing a forcing in 2015, as opposed to the change in forcing in 2015, relative to some earlier time. I could be convinced otherwise, but Roger didn’t seem to be willing to define what he meant by the 2015 radiative forcings and feedbacks.

  14. Willard says:

    I think I now understand the difference: ClimateBall exchanges are forcings because they generate lots of feedback. But most lack real force. Correct?

  15. Yes, but it’s not exactly equivalent to a force in physics 🙂

  16. Catalin C says:

    Just two quick things – the Planck response can not be completely modeled by a single “average” value over the entire Earth, and that is most obvious if you consider the two hemispheres and compare a (hypothetical) scenario where each one warms by 1 degree vs a (hypothetical) scenario were one warms by 2 degrees and the other does not warm at all. In the 2nd example the Planck response would be much bigger even if the amount of average warming would be the same.

    The 2nd observation (and the reason I disliked the entire way Pielke Sr. framed the story) is that ocean heat transport is not something that simply depends just on the amount of radiative forcing present, ocean heat transport varies by more than a factor of 2 from other factors, and as such claims that the OHC depends just on the amount of radiative forcing is misleading at best.

  17. Catalin,
    You’re right that

    \sigma \left[ (T_o + 1)^4 + (T_o+1)^4 \right]/2 - \sigma T_o^4 \ne \sigma \left[T_o^4 + (T_o + 2)^4 \right]/2 - \sigma T_o^4,

    but the difference is quite small for the regime of interest. This essentially comes from the fact that you can approximate the Planck response from

    \Delta F_{\rm Planck} \propto 4 \sigma T_o^3 \Delta T.

    As long as \Delta T is small relative to T_o, the above is reasonable.

    I’m not quite sure what you’re getting at with the final bit of your comment. I think it’s reasonable to argue that the rate of change of OHC is a decent estimate for the planetary energy imbalance.

  18. Catalin C says:

    The delta-T above is small but not insignificant.

    The rate of change of OHC certainly IS a decent ESTIMATE for the planetary energy imbalance, but suggesting that the measured OHC is outside of the energy imbalance suggested by IPCC (as Pielke Sr. seems to try here) requires a far more precise assessment of the effective ocean heat transport during the period involved.

  19. Catalin,
    Okay, yes, I agree.

  20. John Hartz says:

    ATTP: It’s quite obvious Pielke Sr was playing to his adoring fans in Deniersville with his “Wow” Tweet. He is afterall one their “Exalted Ones.”

  21. jsam says:

    You stumped him at scalar versus vector.

  22. dave S says:

    Perhaps this is a UK English thing, but when writers exclaim “Wow” I tend to think they’re barking….

  23. John Hartz says:

    ATTP: I dislike your OP because it forces me to relearn stuff I was taught some 50 years ago during my undergraduate days. 🙂

  24. Albatross says:

    There is another possibility regarding Roger Sr’s “Wow” comment. It could be that Roger Sr. meant “Wow” as in “Wow, I did not know/realise that”.

    That scenario would actually explain his confusion on the subject.

    It would help others understand where Roger Sr. is coming from if he would, on this thread, clarify mathematically what he understands by “forcing” in a climate context versus “forcing” in a Newtonian context. ATTP has done so and what ATTP has shown and described is quite correct.

  25. Willard says:

    A long time ago in a galaxy far, far away:

    ATTP is correct as far as everyone else understands radiative forcings. There is a distinction between radiative forcings which are fixed and the climate changes (the feedbacks) that adjust on the way to a new equilibrium. Your definition of radiative forcing is non-standard, and so perhaps you should expand on what you think RF is. In the standard approach, RF is not a function of the subsequent evolution of the climate. – gavin

    http://www.realclimate.org/index.php/archives/2014/10/ocean-heat-storage-a-particularly-lousy-policy-target/comment-page-3/#comment-614856

    Was this a response to a question Senior asked?

  26. John Hartz says:

    Albatross: May the Force be with you! 🙂

  27. BBD says:

    It would help others understand where Roger Sr. is coming from if he would, on this thread, clarify mathematically what he understands by “forcing” in a climate context versus “forcing” in a Newtonian context.

    “I realised a while back that we were having entirely different conversations”…

    Sorry. All the physics made me do it.

  28. BBD says:

    Willard

    Later on the RC thread you linked (thanks!):

    [Response: ‘radiative flux divergence’ is not ‘radiative forcing’. The definition of radiative forcing has been developed over many years and appears in much of the literature. If you want to talk about something else, with a definition you are supplying, you mught want to try and make that clear right at the beginning so that people don’t get confused and waste their time talking at cross purposes. – gavin]

  29. Willard says:

    Very Tall made AT do it:

    ATTP, now you’ve attracted our attention to Judy’s, the previous post “An alternative metric to assess global warming” appears to be right up your street in terms of applying basic physics to the issues and also features your favourite commenter.

    They appear to conclude that OHC rise is not (or only barely) compatible with stated radiative imbalance from forcings and feedbacks.

    Mud wrestling with a pig

    Sounce Science ™ – Maybe it’s just a vocabulary thing

  30. ‘radiative flux divergence’ is not ‘radiative forcing’.

    They even have different units.

  31. Albatross says:

    “They even have different units.”

    Exactly ATTP! One of the best bits of advice I learned during my undergrad– “check your units!”

    Just for clarity what Roger Sr. was talking about (radiative flux divergence) has units of W m^-2 s^-1, whereas radiative forcing has units of W m^-2. Strictly speaking Roger Sr. should be referring to the “dynamic radiative flux divergence” rather than the “radiative flux divergence”. But whatever…point is that Roger Sr. is confused.

  32. BBD says:

    You are a patient man, ATTP. I hadn’t realised that you and RPSr had been ‘communicating’ elsewhere. I really should keep up.

  33. BBD,
    Only on the RealClimate post, I think.

  34. Pierre-Normand Houle says:

    “The rate of change of OHC certainly IS a decent ESTIMATE for the planetary energy imbalance, but suggesting that the measured OHC is outside of the energy imbalance suggested by IPCC (as Pielke Sr. seems to try here) requires a far more precise assessment of the effective ocean heat transport during the period involved.”

    This glossing over the spatial variations of the radiative imbalance seem minor compared with the glossing over the temporal variations of the imbalance over the whole 60 years period. Pielke Sr’s utilization of his own “exact” formula (GAARI = GAARF + GAARFB) amounts to assuming that the imbalance is constant over the whole period and hence that its value calculated on the basis of observations made near the end of the period ought to be representative of the value for the whole period. This would only be true if (1) there were no internally (e.g. PDO/ENSO, AMO, etc.) driven variations in the top of atmosphere radiative imbalance and (2) the part of the imbalance caused by the external forcing were the exact same from beginning to end. The second assumption is equivalent to the claim that there hasn’t been any increase in the amount of anthropogenic warming still in the pipeline. And this contradicts his explicit simplifying assumption that radiative balance holds at the beginning of the period.

  35. Pierre,

    Pielke Sr’s utilization of his own “exact” formula (GAARI = GAARF + GAARFB) amounts to assuming that the imbalance is constant over the whole period and hence that its value calculated on the basis of observations made near the end of the period ought to be representative of the value for the whole period.

    Yes, I agree. That is essentially the problem with Pielke Sr’s assumptions. The main reason he gets such a discrepant result (compared to models) is that he is implementing the energy balance formalism incorrectly.

  36. > Only on the RealClimate post, I think.

    I supposed this depends upon what “the RC post” means. There is one dated October 2014. In the May 2014 at AT’s, there’s a mention of a previous encounter:

    I once had a reasonably lengthy exchange with Roger Sr about his definition of the term feedbacks, so would be interesting to see what he says here.

    Mud wrestling with a pig

    ***

    > Roger Sr. is confused.

    How to not target Senior’s mind, from A to T:

    Abstruse
    Befuddling
    Confusing
    Daedal
    Enigmatic
    Fanciful
    Glib
    Hermetic
    Idiosyncratic
    Jesuitical
    Knotty
    Labyrinthine
    Mystifying
    Outlandish
    Peripatetic
    Quixotic
    Roundabout
    Scrupulous
    Tutorial

    Adjectives are oftentimes unneeded. In doubt, omit needless words.

    Res ipsa loquitur.

  37. Willard,

    There is one dated October 2014. In the May 2014 at AT’s, there’s a mention of a previous encounter:

    Yes, that was here, about 18 months ago, so not technically “elsewhere”.

  38. BBD says:

    Willard

    Adjectives are oftentimes unneeded. In doubt, omit needless words.

    Fine style advice that bears repeating 😉

    Not least, to myself.

  39. Steven Mosher says:

    style advice that bears repeating.

    just sayin

  40. BBD says:

    Steven

    And then there’s ‘wow’.

  41. Arthur Smith says:

    ATTP – The Planck portion is conveniently well-defined for calculation from models, but it’s arbitrary, not particularly natural or necessarily a good starting point. Andy Dessler argued for a much better reference feedback that includes some of the water-vapor terms in his Ringberg talk – see link and discussion at Eli’s: http://rabett.blogspot.com/2015/03/ringberg-2015-andy-dessler-ecs-2k.html

    The difference is – the Planck response is normally defined by what happens when the temperature everywhere changes by the same fixed amount (say increases by 1 degree C) while “all else” stays the same – including absolute humidity. Dessler (and he’s apparently not the first) merely suggests modifying that to keep *relativey humidity* fixed, rather than absolute – that has several logical benefits and matches reality much better than the rather arbitrary Planck term. I’d encourage everybody to use Dessler’s feedback framework going forward!

  42. Eli Rabett says:

    Non-Newtonian fluids

  43. ‘radiative flux divergence’ is not ‘radiative forcing’.

    They even have different units.

    ???

    radiative flux divergence:The differential increase of radiative flux leaving a region compared to that entering it.

    ‘radiative forcing’ is the ‘radiative flux divergence’ for earth defined at the tropopause under a lot of idealized conditions.

  44. Arthur,
    Yes, I do remember something about that. I’ll have a look, thanks.

    TE,
    I don’t think that changes that the units are still different. Unless I’m mistaken the units of radiative flux divergence are Wm-3.

  45. Following on from Arthur’s comment, here is Andrew Dessler’s talk from Ringberg in which he defines feedbacks with relative humidity fixed, rather than absolute humidity.

  46. Joshua says:

    advice that bears repeating.

  47. WRT water vapour feedback, the theory appears sound, but what that’s meant for the last 35 years over much of the Pacific and Southern Ocean is falling humidity because of falling temperatures there:

    Borne out by the precipitable water vapour:

  48. BBD says:

    Global trends are what drive global warming, TE.

    The April globally-averaged sea surface temperature was 1.08°F (0.60°C) above the 20th century average. This was the highest for April in the 1880–2015 record, surpassing the previous record of 1998 by 0.05°F (0.03°C).

    NOAA

  49. John Hartz says:

    Turbulent Eddie: Why do you refuse to document the source(s) of the graphics that you post?

  50. BBD says:

    Well, his second figure is from AR5 WG1 ch 3 but the first – as so many others – is taken from a closed site owned by a contrarian entity called ‘Climateweenie’ who posts garbage elsewhere. Whether this is TE by (yet) another name I have no idea.

  51. In calculus, a forcing is the term on the right-hand side (RHS) of a differential equation. The left-hand side is the differential equation itself. The forcing is the impulse that the system responds to,

    Many aspects of climate science, from the impulse response to anthropogenic CO2 release to the quasiperiodic behavior of ENSO can be modeled in this way.

  52. Sorry,

    thought you’d immediately recognize the NASA GISS graphics.

  53. Willard says:

    > the NASA GISS graphics

    There’s even an animation:

    What does it have to do with what you said about radiative forcing, Turbulent One?

  54. BBD says:

    So TE, are you ‘Climateweenie’ or not?

  55. I’ve ended up in a Twitter debate with Roger again. He refers to this Chapter of the AR5 report and says

    However, I don’t think that instantaneous means what Roger seems to think that it means. For example, it says

    The instantaneous RF refers to an instantaneous change in net (down minus up) radiative flux (shortwave plus longwave; in W m–2) due to an imposed change. ……

    Climate change takes place when the system responds in order to counteract the flux changes, and all such responses are explicitly excluded from this definition of forcing.
    ……
    In both the Third Assessment Report (TAR) and AR4, the term radiative forcing (RF, also called stratospherically adjusted RF, as distinct from instantaneous RF) was defined as the change in net irradiance at the tropopause after allowing for stratospheric temperatures to readjust to radiative equilibrium, while holding surface and tropospheric temperatures and state variables such as water vapour and cloud cover fixed at the unperturbed values. RF is generally more indicative of the surface and tropospheric temperature responses than instantaneous RF, especially for agents such as carbon dioxide (CO2) or ozone (O3) change that substantially alter stratospheric temperatures. To be consistent with TAR and AR4, RF is hereafter taken to mean the stratospherically adjusted RF.

    I’ll see if I can explain. We essentially have two different RFs, an instantaneous RF and a stratospherically adjusted RF. It appears that Roger thinks that the instantaneous RF is the RF at some instant in time. This, as I understand it, is not correct. It still represents the change in radiative flux resulting from some external change (CO2, the Sun) but it is then determined under the assumption that nothing else changes (i.e., as if it were an instantaneous change). The stratsospherically adjusted RF is also the change in radiative flux resulting from some external change, but it is determined after allowing the stratosphere to adjust, while keeping everything else constant. The different RFs are explained here.

    I’m happy to be corrected if I have misunderstood this, and happy to be corrected if my understanding of what Roger is implying by “instantaneous” is incorrect.

  56. BBD says:

    Well, Willard, now that TE has discovered the cool!!! E. Pacific upwelling he perhaps feels compelled to over-share.

    He might wonder what causes increased upwelling.

  57. I’m happy to be corrected if I have misunderstood this, and happy to be corrected if my understanding of what Roger is implying by “instantaneous” is incorrect.

    Yes, the IPCC defines ‘Instantaneous’ as before stratospheric temperature adjustment as opposed to ‘Adjusted’ after adjustment.

    But it’s a good place to point out that Radiative Forcing is an imaginary number.

    Not because GHGs don’t absorb/emit, but because the calculation is for imaginary circumstances.
    ( instantaneous addition of GHGs, and ‘atmosphere held fixed’ ).

    It’s worth reading over Chapter 8 including ‘Effective Radiative Forcing’ which is the IPCC’s out –
    it means no one really knows how much radiative forcing is actually realized because:

    “Forcing agents such as carbon dioxide can directly affect cloud cover and precipitation, without any change in global temperature.”

  58. BBD says:

    it means no one really knows how much radiative forcing is actually realized because

  59. TE,

    Not because GHGs don’t absorb/emit, but because the calculation is for imaginary circumstances.
    ( instantaneous addition of GHGs, and ‘atmosphere held fixed’ ).

    Well, yes, but the fundamental point is that “instantaneous” doesn’t mean “this is the radiative forcing at this instant in time”, it means “this is the radiative forcing if we determine the effect on the basis of the change being instantaneous”.

  60. Willard says:

    > But it’s a good place to point out that Radiative Forcing is an imaginary number.

    Parsomatics engines might dispute that one:

    An imaginary number is a complex number that can be written as a real number multiplied by the imaginary unit i, which is defined by its property i2 = −1. The square of an imaginary number bi is −b2. For example, 5i is an imaginary number, and its square is −25. Except for 0 (which is both real and imaginary), imaginary numbers produce negative real numbers when squared.

    http://en.wikipedia.org/wiki/Imaginary_number

    “But it’s imaginary” doesn’t quite respond to the question “is Senior’s wowing moment justified”?

  61. Well, FWIW, here’s Roger’s response to my comment. Not only do I still not get how one can define a radiative forcing or a feedback at some instant in time (rather than as a response to some change), it also appears that we’re all nasty mean people here, so Roger’s gone back to WUWT, where everyone is nice and pleasant, there’s no vitriol, and all that they want to do is discuss the science. Maybe Roger regards quote mining as some kind of compliment?

  62. BBD says:

    Yes, well, alternative reality.

  63. Willard says:

    > it also appears that we’re all nasty mean people here

    Here’s a good ClimateBall rule of thumb: when a player rips off his shirt, look for the answer left unsaid. If this answer pertains to the topic of the discussion, the shirt ripping functions as a deflection. In this episode, our quarterback veteran fails to respond to yet another question.

    ClimateBall ™ – Simply Not Simple.

  64. I’ll add this tweet which was part of my conversation with Roger. It appears as though Roger is suggesting that CO2 is not an external forcing, which would seem quite remarkable if so.

    Especially as the full sentence went

    External forcing refers to a forcing agent outside the climate system causing a change in the climate system. Volcanic eruptions, solar variations and anthropogenic changes in the composition of the atmosphere and land use change are external forcings. Orbital forcing is also an external forcing as the insolation changes with orbital parameters eccentricity, tilt and precession of the equinox.

    [Edit 26/5/15 : I just noticed that I copied the wrong full sentence, so have updated it to the correct full sentence.]

  65. John Hartz says:

    ATTP: You might want to drop Tweeting in order to improve your well-being. 🙂

  66. BBD says:

    Actually that definition is a special case. Solar forcing fits but not added CO2 which is inside the system

    Eh?

    Carbon is mined from geological sinks and introduced into the climate system. It is an external forcing.

    Confused, even wrong.

  67. JH,

    You might want to drop Tweeting in order to improve your well-being.

    Yes, people keep telling me that. 🙂 It’s a trade off between being able to respond when someone misrepresents you on Twitter, and not knowing that you’re being misrepresented on Twitter.

  68. The Very Reverend Jebediah Hypotenuse says:

    This exchange from ‘Through the Looking Glass’ seems oddly appropriate…

    ‘There’s glory for you!’

    ‘I don’t know what you mean by “glory”,’ Alice said.

    Humpty Dumpty smiled contemptuously. ‘Of course you don’t — till I tell you. I meant “there’s a nice knock-down argument for you!”‘

    ‘But “glory” doesn’t mean “a nice knock-down argument”,’ Alice objected.

    ‘When I use a word,’ Humpty Dumpty said, in rather a scornful tone, ‘it means just what I choose it to mean — neither more nor less.’

    ‘The question is,’ said Alice, ‘whether you can make words mean so many different things.’

    ‘The question is,’ said Humpty Dumpty, ‘which is to be master — that’s all.’

  69. Eli Rabett says:

    To be willard like, it’s not the CO2, but the carbon that is moved from the lithosphere.

  70. Eli,
    Yes, that is rather Willard like. Aren’t they both external?

  71. Willard says:

    Let’s pay due diligence to the concept of radiative forcing in the glossary the Editor passes at Senior:

    Click to access WG1AR5_AnnexIII_FINAL.pdf

    To prevent any accusation of cherry-picking, I’ll consign all the occurences.

    [1-15]

    Aerosol–cloud interaction

    A process by which a perturbation to aerosol affects the microphysical properties and evolution of clouds through the aerosol role as cloud condensation nuclei or ice nuclei, particularly in ways that affect radiation or precipitation; […] The radiative forcing from such interactions has traditionally been attributed to numerous indirect aerosol effects, but in this report, only two levels of radiative forcing (or effect) are distinguished:

      Radiative forcing (or effect) due to aerosol–cloud interactions (RFaci)

      The radiative forcing (or radiative effect, if the perturbation is internally generated) due to the change in number or size distribution of cloud droplets or ice crystals that is the proximate result of an aerosol perturbation, with other variables (in particular total cloud water content) remaining equal.

      Effective radiative forcing (or effect) due to aerosol–cloud interactions (ERFaci)

      The final radiative forcing (or effect) from the aerosol perturbation including the rapid adjustments to the initial change in droplet or crystal formation rate. […] The total effective radiative forcing due to both aerosol–cloud and aerosol–radiation interactions is denoted aerosol effective radiative forcing (ERFari+aci).

    Aerosol–radiation interaction

    An interaction of aerosol directly with radiation produce radiative effects. In this report two levels of radiative forcing (or effect) are distinguished:

      Radiative forcing (or effect) due to aerosol–radiation interactions (RFari)

      The radiative forcing (or radiative effect, if the perturbation is internally generated) of an aerosol perturbation due directly to aerosol–radiation interactions, with all environmental variables remaining unaffected. Traditionally known in the literature as the direct aerosol forcing (or effect).

      Effective radiative forcing (or effect) due to aerosol-radiation interactions (ERFari)

      The final radiative forcing (or effect) from the aerosol perturbation including the rapid adjustments to the initial change in radiation. […] The total effective radiative forcing due to both aerosol–cloud and aerosol–radiation interactions is denoted aerosol effective radiative forcing (ERFari+aci).

    ***

    Turbulent One might note that the Twomey effect is said to be a largely theoretical concept.

  72. BBD says:

    Eli:

    To be willard like, it’s not the CO2, but the carbon that is moved from the lithosphere.

    Yes, I just said that 😉

  73. Willard says:

    [16-17]

    Climate Feedback Parameter

    A way to quantify the radiative response of the climate system to a global mean surface temperature change induced by a radiative forcing. It varies as the inverse of the effective climate sensitivity. Formally, the Climate Feedback Parameter (a; units: W m–2 °C–1) is defined as: a = (ΔQ – ΔF)/ΔT, where Q is the global mean radiative forcing, T is the global mean air surface temperature, F is the heat flux into the ocean and Δ represents a change with respect to an unperturbed climate.

  74. Willard says:

    [18]

    Climate projection

    A climate projection is the simulated response of the climate system to a scenario of future emission or concentration of greenhouse gases and aerosols, generally derived using climate models. Climate projections are distinguished from climate predictions by their dependence on the emission/concentration/radiative forcing scenario used, which is in turn based on assumptions concerning, for example, future socioeconomic and technological developments that may or may not be realized.

    ***

    Connecting all these concepts together would make for a good post.

  75. Willard says:

    [19]

    Climate sensitivity

    The climate sensitivity parameter (units: °C (W m–2) –1) refers to the equilibrium change in the annual global mean surface temperature following a unit change in radiative forcing.

    ***

    I’ll continue later.

  76. Willard says:

    [20]

    Cloud radiative effect

    The radiative effect of clouds relative to the identical situation without clouds. In previous IPCC reports this was called cloud radiative forcing, but that terminology is inconsistent with other uses of the forcing term and is not maintained in this report.

    ***

    As auditors would say, there may be a dig here.

    SEEPAGE.

    Nooooooooooooooooooooooooooooooooooooo!

  77. Willard says:

    [21-22]

    Effective radiative forcing See Radiative forcing

  78. Willard says:

    [22-23]

    Efficacy

    A measure of how effective a radiative forcing from a given anthropogenic or natural mechanism is at changing the equilibrium global mean surface temperature compared to an equivalent radiative forcing from carbon dioxide.

    ***

    An alternative definition: the opposite of an extensional wordology.

  79. BBD says:

    The IPCC made him do it.

  80. BBD says:

    Like shirt-ripping while leaving the stage, definitional pea-and-thimble is a tactic, not an argument.

  81. Willard says:

    Parsomatics, BBD:

    http://neverendingaudit.tumblr.com/tagged/parsomatics

    A recent episode where some parsomatics has been engineered:

    The dictionary lists “help or stimulate (an activity, state, or view) to develop.” Her behavior and post do “help or stimulate (alarm) to develop”. That’s precisely what I meant and it is what she did. Perhaps if you actually looked up definitions you would gain sufficient mastery of language to not be constantly ‘misunderstood’ and you might not “struggle” so much understanding others.

    http://blogs.nottingham.ac.uk/makingsciencepublic/2015/05/14/lukewarmers/#comment-973142

    I owe the concept of parsomatics to Eli:

    Also, there are questions about what precisely, they have copyright in. As the authors are not employees of ‘ “THE” IPCC’inc, the work can’t be “work for hire”. The review comments are… what? Did the reviewers transfer copyright ownership to ‘ “THE” IPCC’inc? If so, is ‘ “THE” IPCC’inc the sole owner, or do the reviewers co-own with ‘ “THE” IPCC’inc? All these would be interesting questions if ‘ “THE” IPCC’incany UN document — draft, not draft, obtained by hacking etc. is going to fall under fair use for comment most of the time. So whatever case against copying they want to make US copyright law isn’t going to help them much.

    http://rabett.blogspot.com/2012/02/law-blogging.html

  82. Roger Jones says:

    ATTP @6:29

    RP Sr is saying that humans and human activity is part of the climate system if he reckons CO2 forcing is internal. This is an interesting redefinition of the climate system (I am not as lonely as a cloud, I am a cloud) and it shows that he sees the system as a shape, or a geography of different places, not a system of interacting forces. This is enough to show why he is confused by forcings and feedbacks.

  83. Roger,
    Well, yes, but however he might choose to see it, he should be able to define some framework in which we can actually have discussions. It’s one thing to decide to define things differently to how it is normally defined, it’s another to not bother making this alternative clear when having a discussion.

  84. Roger Jones says:

    I don’t think he is capable of doing that, being a rusted on iconoclast.

  85. Possibly, judging by his WUWT comment, it does seem as though, rather than actually explaining his definition, I have to go and read all his papers 🙂

  86. John Hartz says:

    ATTP:

    Moral of the story:

    Never interact with Roger Pielke Sr. without an interpreter — and a bottle of Scotch.

  87. Willard says:

    [24]

    Equilibrium and transient climate experiment

    An equilibrium climate experiment is a climate model experiment in which the model is allowed to fully adjust to a change in radiative forcing.

  88. Willard says:

    [25-26]

    Equivalent carbon dioxide (CO2) concentration

    The concentration of carbon dioxide that would cause the same radiative forcing as a given mixture of carbon dioxide and other forcing components.

  89. Willard says:

    [27]

    Equivalent carbon dioxide (CO2) emission

    The amount of carbon dioxide emission that would cause the same integrated radiative forcing, over a given time horizon, as an emitted amount of a greenhouse gas or a mixture of greenhouse gases.

    “Integrated” radiative forcing. Hmmm.

  90. BBD says:

    Please stop or

  91. BBD says:

    …who knows where it will end.

  92. Willard says:

    The audit never ends.

    [28-29]

    Global Warming Potential (GWP)

    An index, based on radiative properties of greenhouse gases, measuring the radiative forcing following a pulse emission of a unit mass of a given greenhouse gas in the presentday atmosphere integrated over a chosen time horizon, relative to that of carbon dioxide. The GWP represents the combined effect of the differing times these gases remain in the atmosphere and their relative effectiveness in causing radiative forcing. The Kyoto Protocol is based on GWPs from pulse emissions over a 100-year time frame

  93. BBD says:

    The audit never ends.

    To be fair, you did mention that some time ago. I should keep up.

  94. Mal Adapted says:

    Yep, Who knows, alright!

  95. Willard says:

    A radiative forcing “follows” some kind of emission. Hmmm.

    [30]

    Land use change

    Land use change refers to a change in the use or management of land by humans, which may lead to a change in land cover. Land cover and land use change may have an impact on the surface albedo, evapotranspiration, sources and sinks of greenhouse gases, or other properties of the climate system and may thus give rise to radiative forcing and/or other impacts on climate, locally or globally.

  96. Willard says:

    GWP represents the effect of gases “causing” radiative forcing. Ah.

    [31]

    Ocean heat uptake efficiency

    This is a measure (W m–2 °C–1) of the rate at which heat storage by the global ocean increases as global mean surface temperature rises. It is a useful parameter for climate change experiments in which the radiative forcing is changing monotonically, when it can be compared with the Climate Feedback Parameter to gauge the relative importance of climate response and ocean heat uptake in determining the rate of climate change.

  97. Willard says:

    At long last:

    [32-39]

    Radiative forcing

    Radiative forcing is the change in the net, downward minus upward, radiative flux (expressed in W m–2) at the tropopause or top of atmosphere due to a change in an external driver of climate change, such as, for example, a change in the concentration of carbon dioxide or the output of the Sun. Sometimes internal drivers are still treated as forcings even though they result from the alteration in climate, for example aerosol or greenhouse gas changes in paleoclimates. The traditional radiative forcing is computed with all tropospheric properties held fixed at their unperturbed values, and after allowing for stratospheric temperatures, if perturbed, to readjust to radiative-dynamical equilibrium. Radiative forcing is called instantaneous if no change in stratospheric temperature is accounted for. The radiative forcing once rapid adjustments are accounted for is termed the effective radiative forcing. For the purposes of this report, radiative forcing is further defined as the change relative to the year 1750 and, unless otherwise noted, refers to a global and annual average value. Radiative forcing is not to be confused with cloud radiative forcing, which describes an unrelated measure of […]

  98. Does someone have time to investigate this? Does Willis Eschenbach simply not get the difference between an initial value problem (weather and climate predictions) and a boundary value problem (climate projections, average seasonal and daily cycle computations) and as a consequence misquoted Pielke talking about a completely different boundary and also about climate prediction, not projection?

    The boundaries in the context of climate prediction are the ocean surface and the land surface. If these boundaries are fixed in time, evolve independently of the atmosphere such that their time evolution could be prescribed, or have response times that are much longer than the time period of interest in the climate prediction, than one may conclude that climate prediction is a boundary problem.

  99. Willard says:

    If Willis misquoted Senior, then Senior ought to write a blog post challenging Willis. A bit like this:

    Gavin Schmidt should have invited me (or one of our other co-authors to respond). Clearly, however, despite clear evidence of his inadequate lack of knowledge of boundary layer physics, he elected to be the authority on our research papers. This just further documents that Real Climate does not present balanced viewpoints on research papers, but uses misinformation to seek to discredit them. This is a pity, since Gavin Schmidt, if he would educate himself on the issues we raise, could contribute significantly to a constructive discussion of our papers. So far, he has not done so.

    Does Gavin Schmidt Understand Boundary Layer Physics?

    Since this would be worded like Senior allows himself to write, it would meet the most stringent standard in the etiquette of blog science communication.

    Sound Science ™ – Educate Yourself

  100. Willard says:

    Of course, if you prefer less Senior-like, you could say something like that:

    That post of Lucia’s is nothing short of nutty. And Roger calling it “wonderfully clear” just takes the biscuit. I wonder if he’s on a sort of scientific suicide mission.

    http://julesandjames.blogspot.com/2008/05/consistently-wrong-chronicles.html?showComment=1210856940000#c3794337797416237516

  101. Victor,

    Does someone have time to investigate this?

    What’s there to investigate? Isn’t it clear that Willis doesn’t understand the difference between an initial value problem and a boundary value problem?

  102. Investigate whether Pielke understands what a boundary condition is. The “ocean surface and the land surface” are boundaries of the atmosphere, but for most problems, they do not define the boundary (input) of the weather or climate simulation. They are normally modelled and part of the problem, not the boundary of the problem.

  103. Victor,
    Yes, I see. I was rather confused about that response. We probably need to resolve what is regarded as external versus internal, and the definition of a radiative forcing, before moving onto that, though.

  104. Boundary condition problems can be formulated in terms of both spatial and temporal constraints.

    As a case in point, the behavior of ENSO is strongly defined by the boundary conditions of a few periodic forcing conditions. These forcings temporally align the motion of the Pacific ocean to undergo quasi-periodic sloshing movements.

    One of the boundary conditions is set by the nearly periodic cycle which aligns with the upper atmosphere’s quasi-biennial oscillation (QBO) cycle. This is actually a rather strict 2.33 year period that shows some jitter about this value.

    Another boundary condition is the 6.4 year cycle in the variation of the angular momentum of the earth’s rotation known as the Chandler wobble. As everyone knows when attempting to carry a bucket of water, maintaining a constant motion is vital to prevent the water from sloshing in the bucket. The Pacific ocean is no different in this regard, and will undergo a pronounced sloshing motion when guided by strong external forcing from the mechanisms behind QBO and the Chandler wobble.

    The solution to the sloshing problem is covered in texts on hydrodynamics and amounts to a modulated second-order differential equation, with the forcing provided as the stimulus on the right-hand side (RHS) of the DiffEq. The formulation is numerically solved and fit to ENSO metrics such as the Southern Oscillation Index (SOI) and the agreement is striking.

    This model of periodic boundary conditions is substantiated by applying the model to coral proxy records that date back hundreds of years. The evidence strongly supports that both the QBO and the periodic wobble in the earth’s rotation have acted as stationary forcings over the entire period.

    Progress on working this sloshing model is being worked on the Azimuth Project forum, which has an ongoing project to solve the ENSO problem and thus to be able to predict future El Nino events. I also report the progress on my blog ContextEarth, with a submitted research paper at ARXIV.

    Why this rather obvious physics approach has slipped through the cracks of climate science is rather puzzling to me. My own rationale is that ENSO is more of a geophysics model than a climatology problem. It is unlikely that the standard GCM are set up to incorporate the necessary physics and the boundary conditions to describe the well-known angular momentum boundary condition forcings. If they were, then the highly predictable ENSO sloshing would be easily observed in simulation results. In reality all the GCMs show is a chaotic jumble of outcomes that may on occasion show some similarity to the ENSO time-series. They then change initial conditions to generate a stochastic ensemble of time-series. Unfortunately, this has shifted the focus to an initial-value problem. Grrrr. Climate scientists ought to pay more attention to doing as they say instead of saying as they do …

  105. Willard says:

    Almost done.

    [40-42]

    Representative Concentration Pathways (RCPs)

    Scenarios that include time series of emissions and concentrations of the full suite of greenhouse gases and aerosols and chemically active gases, as well as land use/land cover (Moss et al., 2008). The word representative signifies that each RCP provides only one of many possible scenarios that would lead to the specific radiative forcing characteristics. The term pathway emphasizes that not only the long-term concentration levels are of interest, but also the trajectory taken over time to reach that outcome. (Moss et al., 2010). RCPs usually refer to the portion of the concentration pathway extending up to 2100, for which Integrated Assessment Models produced corresponding emission scenarios. Extended Concentration Pathways (ECPs) describe extensions of the RCPs from 2100 to 2500 that were calculated using simple rules generated by stakeholder consultations, and do not represent fully consistent scenarios. Four RCPs produced from Integrated Assessment Models were selected from the published literature and are used in the present IPCC Assessment as a basis for the climate predictions and projections presented in Chapters 11 to 14: RCP2.6 One pathway where radiative forcing peaks at approximately 3 W m–2 before 2100 and then declines (the corresponding ECP assuming constant emissions after 2100) RCP4.5 and RCP6.0 Two intermediate stabilization pathways in which radiative forcing is stabilized at approximately 4.5 W m–2 and 6.0 W m–2 after 2100 (the corresponding ECPs assuming constant concentrations after 2150)

  106. Willard says:

    [43]

    Semi-empirical model

    Model in which calculations are based on a combination of observed associations between variables and theoretical considerations relating variables through fundamental principles (e.g., conservation of energy). For example, in sea level studies, semi-empirical models refer specifically to transfer functions formulated to project future global mean sea level change, or contributions to it, from future global mean surface temperature change or radiative forcing.

  107. Willard says:

    AT,

    Here’s something Senior agrees with:

    A climate forcing is an energy imbalance imposed on the climate system either externally or by human activities. Examples include changes in solar energy output, volcanic emissions, deliberate land modification, or anthropogenic emissions of greenhouse gases, aerosols, and their precursors. A climate feedback is an internal climate process that amplifies or dampens the climate response to a specific forcing. An example is the increase in atmospheric water vapor that is triggered by an initial warming due to rising carbon dioxide (CO2) concentrations, which then acts to amplify the warming through the greenhouse properties of water vapor. Climate forcings are usefully subdivided into direct radiative forcings, indirect radiative forcings, and nonradiative forcings. Direct radiative forcings directly affect the radiative budget of the Earth; for example, added CO2 absorbs and emits infrared (IR) radiation. Indirect radiative forcings create an energy imbalance by first altering climate system components (e.g., precipitation efficiency of clouds), which then lead to changes in radiative fluxes; an example is the effect of solar variability on stratospheric ozone. Nonradiative forcings create an energy imbalance that does not directly involve radiation; an example is the increasing evapotranspiration flux resulting from agricultural irrigation.

    http://www.nap.edu/openbook.php?isbn=0309095069

    Senior cited this as evidence that he and his community (the Pielkesphere?) used “radiative forcing” the way he used it in this previous shell game (H/T James Annan) with Gavin and you. Later he somewhat implicitly conceded that what was being called “radiative forcing” should be referred to as “TOA radiative forcing”.

    See more at: http://www.realclimate.org/index.php/archives/2014/10/ocean-heat-storage-a-particularly-lousy-policy-target/comment-page-3/#comment-614867

  108. Albatross says:

    Willard,

    CAn you please explain the point of all the posts containing “radiative forcing”. I could speculate, but won’t. Anyways, an explanation would help.

    The following statement by senior is not strictly incorrect,

    “Nonradiative forcings create an energy imbalance that does not directly involve radiation; an example is the increasing evapotranspiration flux resulting from agricultural irrigation.”

    Evapotranspiration is very much a function of incoming solar radiation. Look at the definition of the Penman–Monteith equation equation, for example, and note the Rn term (net radiation term).

    http://en.wikipedia.org/wiki/Penman–Monteith_equation

  109. In the RealClimate comment to which Willard links, Roger says

    ‘radiative flux divergence’ is not ‘radiative forcing’

    The two are the same as I define in my modeling book and as a large segment of our community uses the two.

    I agree with you, however, that since the climate modeling community in which you are a member uses a different definition, this has resulted in confusion. (Your approach is more complicated than necessary, in my view, but it is your field to chose as you would like).

    However, now that my definition is clear, I hope comments can move forward to discuss the issues I am raising.

    Does anyone have a source for Roger’s definition of radiative flux divergence and how he has managed to define it as the same as Radiative forcing? I still don’t know what Roger’s definition is.

  110. Willard says:

    Albatross,

    The impetus was provided by a pair of tweets. One of them is this one:

    https://twitter.com/RogerAPielkeSr/status/602851068788088832

    The other is by the Editor’s, where he refers to the IPCC’s Glossary. I’ve got some unfinished business at the Fabius’. Will come back on this afterwards.

    ***

    > The following statement by senior is not strictly incorrect.

    It’s not Senior’s, it’s the NRC’s.

  111. ATTP,

    the flux divergence is just the difference into or out of a given body, in this case the earth/atmosphere defined at the idealized tropopause.

    Now, some of the energy flux into/out of the atmosphere is not radiative energy at the top, but rather sensible heat at the bottom – thus the focus on ocean heat content.

    But radiative forcing IS the radiative flux divergence, defined at the tropopuase, for a bunch of idealized circumstances.

  112. BBD says:

    ATTP

    This excerpt from RPS’s book might help, although there are some gaps.

  113. BBD,
    Thanks, I would like to see Eq. 4.24, but it doesn’t seem to be available. It looks like it’s going to be similar to the one-box model (e.g., as described by Isaac Held).

    C \dfrac{dT}{dt} = F(t) - \lambda T,

    where F(t) is a forcing timeseries. Although, it does still look as though the units of dR/dz is still different to F(t). but Roger should be able to convert if he has a forcing timeseries (which isn’t hard to find).

  114. BBD says:

    ATTP

    Sorry, I meant to link that. See page 48.

  115. BBD,
    Thanks, I think I’ve worked the units out. In the standard one-box formalism, the heat capacity C is normalised with respect to the mass of the relevant part of the system, and the total surface area, so that it has units of J K-1m-2.

    In Roger’s equation, we have

    \dfrac{dT}{dt} = -\dfrac{1}{\bar{\rho} C}\dfrac{dR}{dz},

    in which – I think – C still has units of J kg-1K-1, so that – as expected – dR/dz ends up with units of Js-1m-3. At least, I think that’s right. If so, radiative flux divergence has different units to radiative forcing. One can – I think – convert from one to the other, but they clearly cannot be the same.

  116. BBD says:

    ATTP

    That was an interesting essay and I’m not at all sure why I haven’t already read it 😉 Thanks for the link.

    I was particularly interested to see Held refer to the ’emergent simplicity’ of the transient forced response. One hears any amount of talk about emergent complexity in dynamic, chaotic systems from the ‘you must be joking’ claque, so this was a tonic.

  117. Willard says:

    No hit for “radiative forcing” in Senior’s 100$ manual.

  118. Willard says:

    Another blast from the past:

    Thus, while I agree with Issac that added anthropogenic greenhouse gases will affect the climate, it is not clear that the response will be so close to linear as he has concluded from global climate models. These models have yet to skillfully predict years in advance ENSO, the PDO, the NAO ect, and, the changes in the statistics of these major atmospheric/ocean features on this time scale as a result of anthropogenic climate forcings. His weblog post Summer is warmer than winter oversimplifies the complexity of this issue.

    A Different Interpretation Of Issac Held’s View Of Forced Climate Change

    I smell seepage.

  119. BBD says:

    ATTP

    One can – I think – convert from one to the other, but they clearly cannot be the same.

    This appears plausible in my extremely limited ability to judge 😉

  120. Willard says:

    Sound Science ™ reached new heights at this point of the exchange:

    Roger: I prefer to call my anticipation that next summer will be warmer than the past winter a “prediction” (a very high confidence one, admittedly) and you don’t, and we could discuss this semantic point.

    http://www.gfdl.noaa.gov/blog/isaac-held/2011/04/27/9-summer-is-warmer-than-winter/#comment-188

  121. it is not clear that the response will be so close to linear as he has concluded from global climate models.

    It’s hard to see how it can be strongly non-linear (c.f., Isaac Held again).

  122. This bit of Isaac Held’s comment is also good

    If this signal/noise ratio is too small, than predicting climate anomalies a century from now will be analogous to the prediction of departures from the climatological seasonal cycle (for example, the phase of ENSO) many seasons in advance — and extremely difficult if not impossible due to the underlying chaos in the system. If this signal/noise ratio is large enough, as I am confident it is (I hope to explain my own personal basis for this confidence as these posts evolve) then predicting climate anomalies a century from now, given plausible CO2 trajectories, becomes possible.

  123. BBD says:

    Willard

    I noticed that Held also wrote:

    Each realization from a particular initial condition consists of this forced response plus internal variability, but I want to focus here on the forced response. Observations are not expected to closely resemble this forced response unless the internal variability in the quantity being examined is small compared to the variations in the forced response.

    And, later:

    Additionally, there exist components of the oceanic circulation with decadal to multi-decadal time scales that have the potential to impact the evolution of the forced response over the past century. (This is a different question than whether this internal variability contributes significantly to individual realizations.) I would like to clarify in my own mind whether the ability to fit the 20th century evolution in this particular GCM with the simplest possible energy balance model, with no time scales longer than a few years, is typical or idiosyncratic among GCMs. Other GCMs may require simple emulators with more degrees of freedom to achieve the same quality of fit. There is no question that more degrees of freedom are needed to describe the full equilibration of these models to perturbed forcing, as already indicated by the difference in CM2.1′s transient and equilibrium responses described above, but my question specifically refers to simulations of the past century. I would be very interested if this is discussed somewhere in the literature on GCM emulators. The problem seems to be that accurate computations of the RFP’s felt by individual models are not generally available.

    Which would seem to counter RPSr’s concerns.

  124. Willard says:

    > This bit of Isaac Held’s comment is also good

    I don’t always underline the most relevant bit, but when I do, it’s for ClimateBall’s sake. There was this other episode with James which was also quite good. Here’s a quote to substantiate the “shell game” I alluded to earlier:

    “shell game”

    Yes, although perhaps bait-and-switch would have been a better choice on my part, since the pea is always there, it just changes its meaning seamlessly. In context, “bias” would normally be taken to mean a measurement error but they clearly include real physical effects (such as CO2 warming!) in their use of the term, at least in one place. This seems to be a common Pielkian trait (to be fair, not unique to them) which is one reason why people have such difficulty interpreting their real positions on various topics.

    I’ve been coming across this phenomenon fairly frequently. Another example is the local versus global CO2 forcing thing you pointed to in Eastman et al. RPSnr also has an odd new paper [1] which appears to confuse synoptic short-term response to forcings (think weather modification) to the equilibrium sensitivity. Then the RPJnr thing where he apparently confuses the uncertainty of model predictions due to natural variability, with the uncertainty of measurements due to limited coverage and data processing [2].

    http://initforthegold.blogspot.com/2009/08/pielkes-all-way-down.html?showComment=1250387673313#c3733317464747703667

    Related:

    [1]: The link does not work anymore.
    [2]: http://julesandjames.blogspot.com/2008/05/putting-roger-out-of-his-misery.html

  125. BB says

    “I was particularly interested to see Held refer to the ’emergent simplicity’ of the transient forced response. One hears any amount of talk about emergent complexity in dynamic, chaotic systems from the ‘you must be joking’ claque, so this was a tonic.”

    We have a discussion on this topic at the Azimuth Forum. It is in the context of James Sethna’s concept of “sloppy” models. These are models that manifest themselves with just a few primary factors.

    I think Isaac Held is a big proponent of this approach with his simplified “fruit fly” models.

    Climate science is too complex for its own good, IMO.

  126. Eli Rabett says:

    You bunnies miss the point. Except for natural gas that leaks directly into the atmosphere, fossil fuels and the associated carbon that are dug up from the earth are not climate forcings because they do nothing to the atmosphere. It is only when they are oxidized to CO2 that there is any effect on the atmosphere, but since they are burnt in the atmosphere their effect is internal**.

    **Quibble, organic molecules that are released directly from the oil/coal as they are brought up might be technically thought of as external forcings.

  127. Eli Rabett says:

    t least, I think that’s right. If so, radiative flux divergence has different units to radiative forcing. One can – I think – convert from one to the other, but they clearly cannot be the same.

    Now some, not Eli to be sure, would object to Eli defending Roger, but the fact is that the Bunny has an organiker colleague who sputters when he uses inverse frequency as a unit of energy. Different units, but related by a constant.

  128. Eli,

    Different units, but related by a constant.

    Sure, that was what I was getting at. They might be equivalent, but I think the norm would be to be clear about what quantity you’re discussing. However, I am still not quite clear as to whether or not they are quite equivalent. Either they are and Roger’s suggestion that he can define a radiative forcing at some instant in time is wrong, or they aren’t the same. I can see how one can define a radiative flux divergence at some instant in time, but that wouldn’t be equivalent to a radiative forcing.

  129. BBD says:

    Eli

    It is only when they are oxidized to CO2 that there is any effect on the atmosphere, but since they are burnt in the atmosphere their effect is internal**.

    What about tectonic forcing?

    I thought the salient point was that the carbon came from outside the climate system. The atmospheric chemistry was considered secondary and not enough to render the classification of CO2 as a forcing moot.

    But WTF do I know?

  130. BBD says:

    Eh.

    Let’s tighten that up a bit:

    “The [subsequent] atmospheric chemistry was considered secondary and not enough to render the classification of CO2 as a[n external] forcing moot.”

  131. Willard says:

    Sometimes it’s semantic:

    This is semantic word twisting. A projection is a prediction assuming a specified forcing [in the case of the IPCC “projections” it is the amount of anthropogenically caused greenhouse gases and aerosols and emitted into the atmosphere].

    Climate Science Myths And Misconceptions – Post #5 On Climate Predictions and Projections

    Sometimes it’s more than semantic:

    The term “climate sensitivity” is not an accurate term to define how the climate system responds to forcing, when it is used to state a response in just the global average surface temperature. This is more than a semantic issue, as the global average surface temperature trend has been the primary metric used to communicate climate effects of human activities to policymakers. The shortcoming of this metric (the global average surface temperature trend) was discussed in depth in [the 2005 NRC booklet cited above].

    Repost Of Weblog Climatequotes.com “Climate Scientists Answer Question: Should Climate Sensitivity Be Measured By Global Average Surface Temperature Anomaly?”

  132. Willard says:

    Beware “climate change”:

    What Does “Climate Change” Mean? Does A Lack Of Preciseness In Its Definition Discourage Effective Discussion Of The Risks From Climate On Key Societal And Environmental Resources?

    What Does “Climate Change” Mean? Does A Lack Of Preciseness In Its Definition Discourage Effective Discussion Of The Risks From Climate On Key Societal And Environmental Resources?

  133. I think I’ve worked the units out. In the standard one-box formalism, the heat capacity C is normalised with respect to the mass of the relevant part of the system, and the total surface area, so that it has units of J K-1m-2.

    In Roger’s equation, we have

    \dfrac{dT}{dt} = -\dfrac{1}{\bar{\rho} C}\dfrac{dR}{dz},

    in which – I think – C still has units of J kg-1K-1, so that – as expected – dR/dz ends up with units of Js-1m-3. At least, I think that’s right. If so, radiative flux divergence has different units to radiative forcing. One can – I think – convert from one to the other, but they clearly cannot be the same.

    OK, this describes the heating rate of a layer, dz.

    It’s kinda strange, because when I executed the CRM model for CO2 doubling runs, the individual layers of the troposphere incurred very small changes in heating rate. That’s probably because of the partial absorption by numerous layers.

    But if one considers the troposphere as a whole as a layer, the difference in radiance at the top ( the tropopause ) certainly does imply warming of the whole layer.

  134. TE,

    But if one considers the troposphere as a whole as a layer, the difference in radiance at the top ( the tropopause ) certainly does imply warming of the whole layer.

    Sure, and as I think Eli is pointing out, you can certainly cast a radiative flux divergence in a manner that is consistent with a radiative forcing. That still doesn’t change that it would still have to be related to some kind of change.

  135. BBD says:

    Ex niliho, nihil fit, innit?

  136. Willard says:

    NG reviews Milloy:

    Page 12: “So, according to the definition quoted above the IPCC is talking about changes in forcing (ΔF) at the tropopause even though this is not where we expect to find enhanced greenhouse forcing.”

    You know, since you’re talking so authoritatively about forcing, it might behoove you to look up the definition of radiative forcing. If you’re having trouble finding it, let me help you: it’s in IPCC AR4 WG1 Chapter 2 (PDF), which is entitled “Changes in Atmospheric Constituents and in Radiative Forcing”, and more specifically in Section 2.2, which is entitled “Concept of Radiative Forcing”. There, the very first sentences say:

    “The definition of RF from the TAR and earlier IPCC assessment reports is retained. Ramaswamy et al. (2001) define it as ‘the change in net (down minus up) irradiance (solar plus longwave; in W m–2) at the tropopause after allowing for stratospheric temperatures to readjust to radiative equilibrium, but with surface and tropospheric temperatures and state held fixed at the unperturbed values’.”

    Or, if you’re still wondering what scientists mean by the term radiative forcing, you could thumb forward three pages to FAQ 2.1, “What is Radiative Forcing?” In between, you’ll also find Fig. 2.2, which helpfully illustrates the concept. Perhaps you’re confused because you are imagining radiative forcing to be a change in radiative flux in the final equilibrated state. At that time, the radiation leaving the top of the atmosphere is indeed identical to what it was prior to forcing, and the downward radiation at the bottom of the atmosphere will have changed to some extent. But that’s not what radiative forcing means!

    http://bloggers.chron.com/climateabyss/2012/09/american-thinker-jumps-shark-publishes-steve-milloy/

  137. Eli Rabett says:

    TE, exactly right, what happens is that the top layer (the one that radiates to space in the CO2 band) moves up and it is colder because of the lapse rate, so radiation in the CO2 band is slower and the surface has to heat to maintain balance.

  138. Albatross says:

    Hi Willard,

    Thanks, but you didn’t really help. I now understand what inspired all the quotes; but what is the end goal? It is to…?

    Roger Sr. sat on the committee that drafted the report in question and Roger is keen to take “ownership” of that report when trying to defend his position, so that it has an error is relevant. But, then again, perhaps they unintentionally mangled the wording or an error snuck through somehow. Either way, the assertion in question is not strictly correct.

  139. Willard says:

    > what is the end goal?

    We’ll see when it’ll emerge. There is none beforehand. It’s an audit: who knows where Senior’s tweeted advice may lead.

    Also, it’s an exchange, not a monologue. I don’t know what will happen on the field. All I need to know is my next move. My next move will be to try to articulate all the concepts together. Since I got distracted by looking at how many times Senior expressed his insatisfaction regarding such and such concept, it will have to wait.

    Other projects also emerged. A series of questions I’d like to ask Senior, e.g. if he asked Gavin before publishing his correspondence. Documenting how in his many exchanges with other climate scientists he recycles talking points. Compiling the falls from his blog posts also sounds intriguing.

    ***

    My main constraint is to document instead of editorializing. To show what there is to know instead of saying what to think. Next time the “but radiative forcing” will resurface, I’ll know where to look.

    You ought to try, sometimes. For instance, you could backup your claim that “the assertion in question is not strictly correct.” Citing thy Wiki is not enough in this case: Senior’s tweet requires we look into the IPCC’s documents. Tracing back this definition into Senior’s own research would be even better.

    Also, showing why this error matters might be needed if you’re to use this error to speculate, and sooner or later epilogue. As far as I’m concerned, who cares who mangled what. Errare humanum est, more so in committee.

  140. Albatross says:

    Hi Willard,

    OK, I think I understand where you are coming from now now.

    As for the Penman-Monteith equation, I cited Wiki because it is easily accessible to readers. The source in this case does not matter much the equation is sound and is used by many, many researchers. The formula is key because it represents the latent heat flux (LE, or evapotranspiration) portion of the surface fluxes. The other portion being the sensible heat flux (H). Their sum (LE +H) has to equal the net radiation (Rn) in order to close the surface energy balance. If LE goes up (in magnitude), then H has to go down (in magnitude), as dictated by the conservation of energy.

    So Pielke et al. saying that the increasing evapotranspiration flux creates an energy imbalance is not correct and is at odds with the theory.

    If you don’t like Wiki, then you will find ample information on this in any paper dealing with eddy-covariance measurements in which they are trying to close the surface energy budget, or any paper dealing with estimating ET or any good science text on hydrometeorology.

    If you (or others) would like for me to list some then please just ask and I’ll be more than happy to deliver 🙂

  141. Willard says:

    Thanks, Albatross

    Don’t get me wrong, I love thy Wiki. It’s just verboten according to Senior’s tweet:

    https://twitter.com/RogerAPielkeSr/status/602851068788088832

    Any ClimateBall episode should be a good reason to promote the IPCC’s reports. My own experience with contrarians is that they don’t RTFR. As for myself, delving into the new glossary is just too good to miss.

    ***

    Here’s the fall of one post where Senior mentions evapotranspiration:

    The new Sracklen et al 2012 is yet another example of why land use/land cover change is a first order human climate forcing.

    New Paper “Observations Of Increased Tropical Rainfall Preceded By Air Passage Over Forests” By Spracklen Et al 2012

    The bag of these falls (i.e. including all the repetitions) may indicate something more faithful than Senior’s official position statement.

  142. Albatross says:

    Hi Willard,

    Aha,and now we have come full circle back to Pielke Sr.’s pet tool to distract from anthro GHG forcing, namely land-use and land cover change (aka LULCC). The strong belief that he has that LULCC causes radiative forcing changes on the order as is GHG forcing, is key to his whole argument. It is why he downplays the importance of anthro GHG forcing.

    The Nature by paper by Spracklen et al. (2012) is a good one and nicely demonstrates how important land-atmosphere feedbacks can be at local and regional scales.

    However, it does not support the claim that increasing ET causes a radiation energy imbalance. Instead, healthy transpiring vegetation (and/or high soil moisture) affects the partitioning of the available radiation (Rn-G; where G is the ground heat flux) by increasing LE at the expense of H, so the energy balance is maintained. This change in partitioning of the available energy results in cooler, but more moist near-surface conditions, which in turn can increase the potential for thunderstorms as shown by Spracklen et al.

    IIRC, nowhere do the authors draw the conclusion that Pielke did. Pielke Sr. is overstating and misrepresenting their results.

  143. Willard says:

    Another one before bed:

    A section in every paper of this type titled “Limitations in results presented”, should be a requirement so that readers can more appropriately place such studies in ther proper perspective as “sensitivity studies”.

    Comments On A New Paper “Seasonal Climate Change Impacts On Evapotranspiration, Precipitation Deficit by Harmsen Et Al. 2009”

    Concerns about caveats.

  144. Willard says:

    From the suggested reading links:

    This paper reinforces two issues that have been repeatedly emphasized on climate science and elsewhere:

    1. Adding additional real-world complexity to weather and climate prediction models makes skillful forecasts more difficult. If this difficulty is so serious with respect to seasonal weather predictions, it will be even more so for multi-decadal global climate predictions.

    2. The regional models cannot correct for biases (i.e. errors) in the parent global model. Regional dynamic model downscaling based on output from parent models (such as the IPCC multi-decadal projections) cannot add predictive skill over and beyond what is already present in the parent model. If the parent model (e.g. an IPCC simulation) does not have all of the climate forcings and feedbacks that are important on multi-decadal climate time scales, the regional model cannot correct for these shortcomings.

    A New Paper “Ensemble Re-Forecasts Of Recent Warm-Season Weather: Impacts Of A Dynamic Vegetation Parameterization” By Beltan-Przekurat Et Al 2008

    The last sentence of #1 looks like a fallacy and the #2 creates a double bind in the light of #1. Also note: bias, shortcoming, IPCC.

    Yet another paper that reinforces Senior’s main conclusions:

    The Climate Science Weblog has clearly documented the following conclusions since July 2005:

    Main Conclusions

    Compare these conclusions with the questions to Gavin. In fact, compare these conclusions with just about any of Senior’s exchanges.These exchanges look like opportunities to “reinforce issues” more than anything.

  145. Willard says:

    Speaking of unfinished business at the fabulous Fabious’, I left a comment:

    Dear Editor,

    My first comment pertained to the smarmy concerns expressed both by Senior and in your own editorial. Your own concerns are a bit moot considering your latest scattered shots. Senior’s concerns have little merit considering his usual modus operandi, and now that we can read back how his ClimateBall exchange evolved with AT.

    Your response regarding my competence was unresponsive to that first point. Nor is doubling down with your scattered shots responsive to that point. Questioning my competence only serves to excuse yourself from answering my second comment, which pertained to your misinterpretation of psychological predicates. This other response was also an excuse for your dignified unresponsiveness regarding my first point.

    ***

    Your scattered shots may indicate some kind of openness. I will address what I believe is your main shot, while acknowledging your anonymous authority:

    > I have sat through hundreds (thousands?) of hours of discussions about expert analysis […]

    I doubt these hours of discussion were made in what we would call a critical discussion [1], whose object is seldom (if never) about the interlocutors, but about their arguments. Unless one can show how an interlocutor’s competence is relevant to what the interlocutors say, using such talk as argument would be fallacious.

    The best we can say about such cheap ad homs is that they are offered as justification to bring the communication to a close. People do that all the time. Including scientists: both Senior and AT did that. The main difference is that Senior can’t bring himself to disengage, which is part of his modus operandi alluded to above.

    ***

    So that’s for your “I’m big in Japan” move. (My canned response to such silly appeal to authority are: sure, and I’m a ninja.) If you want a response to any other ones, feel free to ask.

    Beware your wishes,

    W

    [1]: http://en.wikipedia.org/wiki/Pragma-dialectics

    Let’s hope the Editor will take the fig leaf.

    PS: In restrospect, Albatross, I think the answer you were looking for earlier is contained in the expression modus operandi.

  146. Louise says:

    I see ATTP is now in e-mail dialogue with RPSnr. Be prepared to have selected exerpts reproduced at WUWT as per RPSnr’s modus operandi.

  147. Willard says:

    Perhaps more relevant to this thread, an historiographical note:

  148. Willard says:

    Stop the press!

    Senior is now ready to move on:

    https://twitter.com/nevaudit/status/603907920447823872

    Some “F=MA” were thrown previously in that discussion.

  149. pbjamm says:

    Willard, I generally enjoy your input into discussions (though I dont always understand it) and I admire your perseverance in the face of aggressive dismissiveness but…

    As someone who does not Twitter the excerpts from an already under-charactered discussion are just a word salad to me. I get that at the end there Senior has yet again kicked over the board and blamed everyone else for ruining the game. Can you summarize the ‘debate’ in 141 characters or more?

  150. Willard says:

    Will try tomorrow, pbjamm. Am a bit busy right now convincing Oliver Geden that not all scholars appreciate today’s academic press business model.

    To understand the context of tweets, click on the date at the bottom of them. This should lead you to the conversation, if you can call that so.

    Thank you for the kind words,

    W

    PS: I don’t always understand what I do either, so at least we have this in common. I guess it removes some bias in what I do.


  151. “Forcing” comes from differential eq’ns “forced” (or inhomogeneous) vs “free” (homogeneous) solutions

    Kinda slow on the uptake.

    #comment-56827

    Lots of people talking past each other on this topic.

  152. Marco says:

    “I am moving on to others who are actually talking about science, not semantics”.

    Let’s use that excuse every time Pielke Sr claims someone has described something incorrectly. “All semantics, Roger, I’d rather talk to those who talk about science.”

  153. The Very Reverend Jebediah Hypotenuse says:

    “Forcing”

    Lots of people talking past each other on this topic.

    Welcome to the internets.

    Let us now take up the topic boundary conditions…
    https://archive.is/LpZfG#selection-653.0-657.30

    All your semantics are belong to us.

  154. Susan Anderson says:

    Oddly, having read the exchange at RealClimate when it came out, this reminded me of how it felt then. There’s no getting anywhere with all this; you expect logic, but that’s not what it’s about.

    Lots more in this chapter:
    https://www.cs.cmu.edu/~rgs/alice-V.html

    `I haven’t the least idea what you’re talking about,’ said Alice.

    `I’ve tried the roots of trees, and I’ve tried banks, and I’ve tried hedges,’ the Pigeon went on, without attending to her; `but those serpents! There’s no pleasing them!’

    Alice was more and more puzzled, but she thought there was no use in saying anything more till the Pigeon had finished.

    `As if it wasn’t trouble enough hatching the eggs,’ said the Pigeon; `but I must be on the look-out for serpents night and day! Why, I haven’t had a wink of sleep these three weeks!’

    `I’m very sorry you’ve been annoyed,’ said Alice, who was beginning to see its meaning.

  155. Pielke even gets that wrong. Boundary conditions don’t have to be only spatial. They can also be temporal — for example, a periodic forcing that serves to align a response function over time so that it stays “on the leash” so to speak.

  156. for example, a periodic forcing that serves to align a response function over time so that it stays “on the leash” so to speak.

    That’s not a boundary condition, that’s a property of the forcing.That enters the mathematical formulation of the problem in a totally different way.

  157. Willard says:

    > I get that at the end there Senior has yet again kicked over the board and blamed everyone else for ruining the game. Can you summarize the ‘debate’ in 141 characters or more?

    Your feeling is not far from being what has been accomplished, pbjamm. To get the modus operandi into action, let’s start by how it oftentimes start:

    https://twitter.com/RogerAPielkeSr/status/603662710618861568

    First, the “anonymous!” card. Senior conflates pseudonymity and anonymity here. More importantly, he forgets that he cited a post where AT was mentioned by name. In matter of minutes an Egg face linked to Pop’s, and Richard Tol competed with others to fill up the relevant details.

    Second, the “rude!” card. Yes, right after having played the “anonymous!” card in an episode which starts with a “wow,” an episode that follows another one that started at Tony’s, and right after “updated” his experience of AT’s. You can’t make this up.

    Third, the “colleague!” card:

    https://twitter.com/RogerAPielkeSr/status/603615867285438464

    Notice the smarmy dots. This card has been played right after Senior declared at Tony’s that Gavin wasn’t his “colleague”. There, it was more “you’re a director, all your answers belong to us”.

    Fourth, the “not me!” card:

    https://twitter.com/RogerAPielkeSr/status/603627074520223744

    Of course Senior would never stoop at the level of personal attacks. Fishing out quotes from AT’s about page, whining about anonymity and rudeness, wowing, bitching about AT’s, and questioning his interlocutor’s competence based on silly word games are just normal activities in a scientist’s life. Nothing personal there.

    ***

    The story goes on. I need to go.


  158. That’s not a boundary condition, that’s a property of the forcing.That enters the mathematical formulation of the problem in a totally different way.

    If I drive an audio amplifier with an input consisting of a musical tune, the boundary condition is that musical tune. The response is that tune amplified and possibly filtered so that establishes what is heard. It is not an initial condition because the input is constantly keeping the output aligned.

    Give it a rest Pekka and quit being such a scold.

    So #WHUT does that make me ? 🙂

  159. If I drive an audio amplifier with an input consisting of a musical tune, the boundary condition is that musical tune.

    Really?


  160. Really?

    Whereas if you put that input though an amplifier that does the same thing as a Lorenz equation, you will get chaos that looks nothing like the input.

    In many cases, the input is the boundary condition “leash” that guides the output.

    We are making great progress in showing that the phenomenon of ENSO is not as complicated as many would lead you to believe — it is in fact governed by well-known hydrodynamics that can be effectively modeled with a modified second order differential equation and the appropriate cyclic forcing.

    That’s how scientific progress is made Pekka, not by your constant negativity and scolding.

  161. The Very Reverend Jebediah Hypotenuse says:

    All parts should go together without forcing.
    Therefore, if you can’t get them together, there must be a reason.
    By all means, do not use a hammer.

    – IBM maintenance manual, 1925

  162. Willard says:

    The fundamental theorem of forcing is that, under very general conditions, one can indeed start with a mathematical structure M that satisfies the ZFC axioms, and enlarge it by adjoining a new element U to obtain a new structure M[U] that also satisfies ZFC. Conceptually, this process is analogous to the process of adjoining a new element X to, say, a given ring R to obtain a larger ring R[X]. However, the construction of M[U] is a lot more complicated because the axioms of ZFC are more complicated than the axioms for a ring. Cohen’s idea was to build the new element U one step at a time, tracking what new properties of M[U] would be “forced” to hold at each step, so that one could control the properties of M[U]—in particular, making it satisfy the negation of CH as well as the axioms of ZFC.

    Click to access Beginner%27s%20guide.pdf

    I have no idea what this means, but I find it beautiful.

  163. BBD says:

    And listen.

  164. Willard says:

    Before you type, preferably. Or as you type, if you’re me.

    One of my favorite albums evah, BBD.

  165. anoilman says:

    I think its safe to say that Roger A. Pielke Sr is a failure. He’s failed to explain his position. He’s failed to provide evidence. Then he failed to show up and defend himself.

    Clearly this is a victory for andthentheresphysics.

  166. Eli Rabett says:

    Clearly anoilman does not understand Roger’s boundary conditions.

  167. Eli – aren’t Roger’s initial conditions and boundary conditions one and the same?

  168. Willard says:

    > Roger’s initial conditions and boundary conditions one and the same?

    Semantics in, semantics out, with some concerns about tone, collegiality, and authority. In between, a furious recursion of the talking points one can read on this page:

    1. The needed focus for the study of climate change and variability is on the regional and local scales. […]

    2. Global and zonally-averaged surface temperature trend assessments, besides having major difficulties in terms of how this metric is diagnosed and analyzed, do not provide significant information on climate change and variability on the regional and local scales.

    3. Global warming is not equivalent to climate change.

    4. The spatial pattern of ocean heat content change is the appropriate metric to assess climate system heat changes including global warming.

    5. [T]he IPCC Reports, the CCSP Report on surface and tropospheric temperature trends, and the U.S. National Assessment have overstated the role of the radiative effect of the anthropogenic increase of CO2 relative to the role of the diversity of other human climate forcings on global warming, and more generally, on climate variability and change.

    6. Global and regional climate models have not demonstrated skill at predicting regional and local climate change and variability on multi-decadal time scales.

    7. Attempts to significantly influence regional and local-scale climate based on controlling CO2 emissions alone is an inadequate policy for this purpose.

    8. A vulnerability paradigm, focused on regional and local societal and environmental resources of importance, is a more inclusive, useful, and scientifically robust framework to interact with policymakers, than [other things that goes beyond Senior’s area of expertise].

    Main Conclusions

    All the so-called “discussions” I’ve read with Senior end up becoming opportunities for him to peddle these talking points. Most if not all his posts have a fall related to these points, unless they reinforce the smarmy wrapper of semantics, tone, collegiality, and authority concerns.

  169. anoilman says:

    Eli… or even the middle bit.

    He’s like the Otto of the scientific community;

  170. Albatross says:

    Willard found a peculiar assertion made Pielke Sr. on Twitter. Roger claims,

    “I agree. I will never stoop to that level. It accomplishes nothing”

    Wow! History shows that claim by Pielke Sr. to be absolutely false. Sr. is trying to fool Fabius maximus and others on Twitter.

    Read the following thread and follow the embedded links:
    http://www.skepticalscience.com/SkS-Weekly-Digest_20.html

    He seems to have deleted the images, but the internet does not forget Roger 😉

    https://web.archive.org/web/20130126114351/http://pielkeclimatesci.wordpress.com/2011/07/19/ignored-request-for-nsf-to-respond-on-the-issue-of-downscaling/
    https://web.archive.org/web/20131014102020/http://pielkeclimatesci.wordpress.com/2011/10/05/erroneous-information-in-the-report-procedural-review-of-epas-greenhouse-gases-endangerment-finding-data-quality-processes/

    In fact Pielke Sr. has stooped to “that level” by insulting scientists on his blog, and at times he has most certainly not held the moral high ground on his blog and on the internet. I do agree with Pielke Sr. then, his attitude and treatment of others has accomplished nothing.

  171. Willard says:

    Let us stay classy, please.

  172. Eli Rabett says:

    7. Attempts to significantly influence regional and local-scale climate based on controlling CO2 emissions alone is an inadequate policy for this purpose.

    But it is a necessary step, and in many cases may be sufficient.

  173. John Hartz says:

    Given that Pielke Sr. has gone over to the Dark Side (Deniersville), the best way to deal with him is to simply ignore him.

  174. Willard says:

    > to simply ignore him.

    How do you know that, JH?

    ***

    A more recent example, Albatross:

    https://twitter.com/RogerAPielkeSr/status/602830641323855872

    The “science” card is pervasive in ClimateBall. The mind reading adds a nice touch.

    I recall having seen the Pinocchio image at Junior’s.

  175. Given that Pielke Sr. has gone over to the Dark Side (Deniersville), the best way to deal with him is to simply ignore him.

    Currently we are engaged in what – so far – has been a constructive email exchange.

  176. John Hartz says:

    ATTP: A private email exchange is a much more appropriate forum for scientists to engage in a serious discussion of scientific matters than are Twitter or the coment threads of blog posts where particpants are typically playing to their admiring followers. Kudos to you for doing so with Pielke Sr.

  177. Willard says:

    > But it is a necessary step, and in many cases may be sufficient.

    Senior’s judgment regarding an “inadequate policy” seems to conflict with the “I’m not a policy analyst” card I’ve seen him play when asked about policy-making, e.g.:

    In terms of how to involve scientists in working with policymakers, I recommend my son’s books

    Interview With James Wynn In The English Department At Carnegie Mellon University

    His judgment may also presuppose the linear model. Honest brokers react negatively to that model. How is the linear model a model is not a question I’ve ever seen them answer.

  178. Willard says:

    Let’s not forget the tweet that made me visit Fabius’:

    https://twitter.com/RogerAPielkeSr/status/602100953551011840

    At least it started with the Editor praising the conversation at AT’s. This laudatio has a bit toned down in the hours that followed. What a ClimateBall day or two can do.

  179. John Hartz says:

    Willard:

    How do you know that, JH?

    There’s no need for us to waste valuable time and energy rehashing Pielke Sr.’s well-known contraian positions. As has been noted on this thread, discussions with him generally follow the same worn-out script.

  180. Willard says:

    > discussions with him generally follow the same worn-out script.

    One does not simply break out of that script by ignoring it, JH. ClimateBall history shows where ignoring it leads. First, script the script. An algorithm would be better. A rule-based system would be best:

    http://en.wikipedia.org/wiki/Rule-based_system

    There’s no need to go that far. However, there’s a need to find the preconditions that trigger the script.

    ***

    Moreover, that behavior has been reinforced. Senior does not act ab nihilo. Revisit how the discussion at SkS evolved. You really could not find another cartoon than one with a “Roger” in it?

    This choice of cartoon reveals you have no idea whom you are confronting. It shows poor ClimateBall skill. Reread your preemptive strike:

    Lest there be any confusion, the above Toon of the Week satirizes how Fox News and other like media outlets perpetuate the myth of scientific debate by giving equal weight to the findings of legitimate scientists and the opinions of non-scientists. The fact that the couch potato in the toon is named “Roger” has absolutely nothing to do with Dr. Roger Pielke Sr., a distinguished scientist.

    http://www.skepticalscience.com/SkS-Weekly-Digest_20.html#65625

    You linked to a story involving Senior in your review. This is quite suboptimal, JH.

    Worse, you’re doing the very same thing on this very thread, i.e. let’s ignore Senior, but let’s exchange emails with him. Notice how you decide to portray Senior in that defense: a distinguished scientist. Compare with what your guilt by association you just used to dismiss him as a valid interlocutor: gone over to the Dark Side (Deniersville).

    If you don’t care about ClimateBall, JH, stop playing ClimateBall, and stick to science and linking random articles you read.

  181. John Hartz says:

    Willard:

    The SkS Weekly Digest your refer to was posted in Oct 2011. My opinion of Roger Pielke Sr. has evovled over the intervening years. The fact that he chose to pose questions to Gavin Schmidt in a post on WUWT is, in my opinion, disgusting. He then compounded his effrontery by posting the texts of Schmidt’s emails to him in the comment thread.

    Re the Toon of the Week, I did not notice that the name “Roger” was in the text ballon until Pielke Sr cried fowl. You won’t believe that, but frankly I don’t give a damn.

  182. Willard says:

    Compare and contrast how this thread evolved and that other one linked in JH’s weekly review. More specifically, notice how it derails, and why. Look at what is being said. For instance, #36:

    Dr. Pielke, you made a rather odd statement: […]

    http://www.skepticalscience.com/pielke-sr-and-sks-warming-estimates.html#65058

    From then on, the Gods of Snark and Smarm gradually take over and ClimateBall reach 11 at around #40:

    You are not debating; you are lecturing.

    http://www.skepticalscience.com/pielke-sr-and-sks-warming-estimates.html#65073

    Another common card by Senior: “no debate!”.

  183. Willard says:

    > I did not notice that the name “Roger” was in the text ballon until Pielke Sr cried fowl. You won’t believe that […]

    I don’t see why I should not believe you. You still can’t prove that except by appealing to your own mind states. This is invalid.

    Even if you did not intend any snark, if you care about Senior’s smarm at all, you take back that stupid cartoon, you apologize for the inconvenience, and you present another one.

    If you don’t care about Senior’s concerns, you don’t need that stupid excuse.

    ***

    > My opinion of Roger Pielke Sr. has evovled over the intervening years.

    It even evolves over the minutes:

    A private email exchange is a much more appropriate forum for scientists to engage in a serious discussion of scientific matters than are Twitter or the coment threads of blog posts where particpants are typically playing to their admiring followers. Kudos to you for doing so with Pielke Sr.

    That was posted two hours ago, right after conselling we ignore Senior because he has gone over to the Dark Side!

    Why would you engage in a serious discussion with someone who has gone over to the Dark Side (Deniersville), again?

    This is unwinnable, JH. Ignore me at your own risk.

  184. John Hartz says:

    Willard:

    There’s a world of difference between a climate scientist such as ATTP engaging in a private email conversation with Roger Pielke Sr. and the rest of us engaging him in the social media.

  185. Willard says:

    > There’s a world of difference between a climate scientist such as ATTP engaging in a private email conversation with Roger Pielke Sr. and the rest of us engaging him in the social media.

    I don’t think “the rest of us engaging him” correctly describes what you called “rehashing Pielke Sr.’s well-known contraian positions”, JH. Yet another instance where your framing changes in a radical manner. Your private/social wedge cuts very little ice too: either we ought to engage with someone who has gone to the Dark side, or not. The type of channel is irrelevant to that ethical stance.

    Also, I don’t think many here is “engaging with him.” Conversely, Senior ignored all but one questions I asked him. Since his only response played against his shirt ripping at Tony’s, I don’t expect him to respond to me again.

    Finally, I don’t think that analyzing Senior’s script is time wasted.

    ***

    Here may be why Senior relies on that instantaneous doctrine:

    “the radiative forcing requires a baseline year.”

    is not correct. The quote you have states

    “ΔF is the change in forcing”.

    That does require a base year. The forcing does not and is instantaneous.

    One would never state that “acceleration requires a base time period.” Acceleration is the derivative of the velocity at any time. Similarly, radiative forcing is at a specific time although one could time average (e.g. the yearly global averaged radiative forcing).

    http://www.skepticalscience.com/pielke-sr-and-sks-warming-estimates.html#65078

    Vintage 2011. At John’s. Fancy that.

    It may not only be a semantic point, after all.

  186. BBD says:

    Finally, I don’t think that analyzing Senior’s script is time wasted.

    I would agree. I’ve found Willard’s commentary on events – and terminology – extremely useful as I am too lazy to go and find all this stuff out for myself. I appreciate the effort that Willard has spared me 🙂

    Also, as a non-tweeting entity, I’d miss *everything* that goes on in the tweet-o-sphere were it not for the selected highlights (re) presented in these august pages by W.

  187. There’s a world of difference between a climate scientist such as ATTP engaging in a private email conversation with Roger Pielke Sr.

    Climate scientist is a bit of a stretch. In this context, just a scientist.

  188. John Hartz says:

    ATTP:

    Out of curiousity, did you and Pielke Sr. agree up front to keep your email exchange private?

  189. John Hartz says:

    Willard: Other than posting them on this thread, what do you intend to do with your analyses of Pielke Sr’s script?

  190. Willard says:

    > Other than posting them on this thread, what do you intend to do with your analyses of Pielke Sr’s script?

    The good ol’ “let’s pretend we’re into a job interview and let me ask you tough questions” decoy, JH. Right after having ignored everything I said or tried to frame your way out of your SkS mess. That’s just great.

    ***

    Nevertheless, here are my intentions so far:

    – linking back to this thread when Senior will repeat his modus operandi somewhere else;

    – documenting this modus operandi the best I can;

    – analyzing it to understand how it works;

    – abstracting this modus operandi into an algorithm;

    – writing a poem to reflect that modus operandi, for poetry’s sake and for mnemonics;

    – generalizing the procedure to identify where else parts of this MO appears in ClimateBall;

    – connecting this with argumentation theory, as it substantiates the dynamic aspect of it (for a new project called RHETORICS ™);

    – writing something more formal, which may or may not become a paper, a thesis, whatever.

    ***

    This question presumes that these ClimateBall episodes are of lesser value than a “real” scientific discussion. While this may correspond to our actual experience of it, this is only contingent to the fact that ClimateBall players don’t realize the importance of ClimateBall. We are in a somewhat public sphere, and this is where ideas ought to be debated. There’s very little reason to prefer a predatory and outdated publishing system. What I write under my name is my honor, and very little of what I write here could not become part of the lichurchur, pending clarification and more time to edit, it goes without saying.

    Welcome to the Internet.

  191. John Hartz says:

    Willard: How does what you do impact public opinion about the need to take meaningful action on the climate change front?

  192. John Hartz says:

    Willard: I have no compelling reason to respond to your personal insults of what I did and said in Oct 2011. You have set yourself up a judge, jury, and executioner. I do not recognize your authority to do so.

  193. Okay, maybe we can avoid another Willard vs JH comment thread.

  194. Pingback: 2015 blog summary | …and Then There's Physics

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