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Comments 94351 to 94400:

94351. les at 00:06 AM on 26 February 2011
       2nd law of thermodynamics contradicts greenhouse theory
       366... clearly, and again, we all appreciate the complexities. And, again, I never said gas, I said 'body'. Boltzmann et al don't care what it's made of. Introducing both complexities and irrelevant factors (prompt photon emission? 'prompt' for e-m radiation, is a technical term regarding decay from excited states; does that matter here do you think?) prevent one from seeing the basic facts of the matter which bound such problems - which is the point of idealized models. I really did think going back to basics would help. But I can see that the road is to long and, really, rather than nowhere to go, I have better places to go!
94352. Tom Curtis at 23:48 PM on 25 February 2011
       Climate sensitivity is low
       RW1: 1) When physicists refer to "the atmospheric window" they refer to a portion of the spectrum in which radiation is not absorbed, so radiation can pass through that "window" without appreciable loss or distortion. The atmosphere has several windows - one at the frequencies of visible light, another in the IR spectrum, and still others in the radio spectrum. 2) One of the atmospheric windows in the IR spectrum is in that range of frequencies where the majority of the surfaces IR radiation is emited. As a result, about 40 w/m^2 of IR radiation escapes to space without being absorbed by any atmospheric components (except clouds, if present). 3) Increasing CO2, O3 or H2O content into the atmosphere, or introducing novel GHG can narrow this window slightly, but the effect is very small. 4) Outside of the atmospheric window, IR radiation from the Earth's surface is entirely absorbed by GHGs; but 5) Those GHGs then emit radiation at the same frequency at an intensity that depends on their temperature. The IR radiation emitted towards space by GHGs is then absorbed by higher GHGs, which in turn emit radiation at an intensity depending on their temperature, which is in turn absorbed and so on until the atmosphere is thin enough for the upward emitted radiation to escape to space. 6) Because the radiation outside the atmospheric window that escapes to space is emitted high in the atmosphere, it is emitted by gases that are much cooler than the surface. Therefore, that radiation has a much lower intensity, ie, transmits much less energy than the radiation emitted from the surface at the same frequency. The difference between the energy that is radiated to space outside of the atmospheric window and the energy originally radiated from the surface at those same frequencies is the fundamental basis of the green house effect. 7) If you increase the concentration of a GHG, then the altitude at which radiation from that GHG will effectively escape to space will increase. Because the altitude has increased, the temperature of the radiating gas is lower, so the total energy radiated is also lower. 8) If you double the CO2 concentration, the atmospheric window will narrow slightly as the absorption band of CO2 widens. This does not mean no IR radiation will escape in the frequencies where the absorption band widens - it just means that the IR radiation in those frequencies will come from a higher, ergo cooler, ergo less energetic altitude, reducing the total IR energy escaping in that frequency band by about a third. 9) At the same time, IR in the frequencies of the previously existing absorption band will come from slightly higher in the atmosphere, and therefore carry less energy (because the emitting CO2 is colder). 10) The combination of these two effects will reduce the total energy leaving the atmosphere by 3.7 w/m^2 That is the full and complete answer to your questions (given space limits). It has been given to you ad nauseum above but you refuse to hear the answer because it is not framed according to the frankly fallacious model of the Green House effect used by George White. However, we cannot ignore the physics and give you answers that only make sense if framed in terms of George White's fallacious physics. If you try frame your question in terms of the actual physics, however, you will find you have already been answered repeatedly.
94353. damorbel at 23:37 PM on 25 February 2011
       2nd law of thermodynamics contradicts greenhouse theory
       Re 364 les You wrote:- "Clearly. I was starting, as you observe, from an ideal model" If you start your model as a gas 'behaving like a black body' you really have nowhere to go because the odd CO2 (or H2O) molecule (at the density in the atmosphere - think of the thickness when brought to the surface and liquified) will never get anywhere near absorbing all the radiation from the surface. Even this observation is utterly irrelevant because any radiation absorbed by CO2 & H2O in the atmosphere is promptly re-emitted, if it wasn't the temperature of the intermediate layers would change. The atmosphere really is not, as far as radiation is concerned, different from a solid. Radiating solids also need internal heat transport to get the heat to the emitting suface. The emitting surface of solids is not an ideal, theoretical model; it is very complex and depends on the exact composition of the surface, which is seldom the same as the bulk material, it is an oxide or dirt or something.
94354. Dikran Marsupial at 23:18 PM on 25 February 2011
       It's not us
       Julian: I note that you have failed to attempt to engage with the challenge I suggested, namely: "Try giving a specific example, giving values for all natural and anthropogenic sources and sinks, where the annual rise is less than anthropogenic emissions and where the natural environment is a net source. You will find that you are unable to do so, but the attempt will probably demonstrate to you why the mass balance argument is correct." Can you explain why you responded to every part of my post, except that one? Regarding the analogy regarding bank balances, it seems I will have to spell it out. The partner represents the natural carbon cycle, all of it, so there is no benificent uncle (unless you think aliens are coming here in flying saucers and taking carbon from the atmosphere). As I said, we don't need to know anything about the transactions performed by the partner to know that he/she is a net sink. [S]He could be putting in and taking out millions of dollars a month, or hundreds, and it wouldn't make any difference to the argument at all. The change in bank balance only depends on the difference between income and outgoings, not on the volume of transactions. You say I that I believe all sources and sinks are accounted for. That is not correct, and the mass balance argument does not depend on knowledge of the sources and sinks, I have said that repeatedly, so you ought to know that by now. The mass balance argument is a means of inferring the difference between total natural emissions and total natural sources. That is all you need to know to be sure that nature is a net sink and hence CO2 levels would be falling if not for our emissions. Now, please try an address the challenge repeated above, can you give a counter-example, using any values you like for the fluxes, even if they are not realistic (as long as they are positive real numbers). If you are not willing to try, or not willing to admit that you can't find a counter example, what would that imply?
94355. les at 23:15 PM on 25 February 2011
       2nd law of thermodynamics contradicts greenhouse theory
       364- in 2/ "same amount of energy" should read "same amount of energy / unit time".
94356. RickG at 23:01 PM on 25 February 2011
       Climate sensitivity is low
       RW1: By 'atmospheric window', I'm referring to the amount of the emitted surface power that passes through the atmosphere completely unabsorbed by GHGs or clouds. How do you distinguish what is surface emitted from other emitted sources. And why do you use the word "power"? What is power?
94357. Jesús Rosino at 23:00 PM on 25 February 2011
       How We Know Recent Global Warming Is Not Natural
       I was translating this article and there's one thing I don't undertand. The article says that:

       even a 2°C climate sensitivity would mean that humans have been responsible for more than half of the global warming over the past century.

       However, I don't see how climate sensitivity can affect the distribution between different climate forcings. Natural forcings alone would likely have cooled the planet, so I think we are likely responsble for more than 100% of the warming. Given that ΔT=ΔRF*S, with a given temperature rise (ΔT = 0.8ºC), the fact that climate sensitivity (S) is low, would just imply that the net radiative forcing (ΔRF) has been rather high (i.e. high RF and not that high temp rise), and if the climate sensitivity is high, that would just imply that the net radiative forcing (ΔRF) has been rather low (i.e. low RF and high temp rise). But I don't think that this affects the distribution among forcings, i.e., humans would still be the major contributors to global warming. So I don't see the relationship that the sentence I quoted above means to establish, and I even think the sentence is understating our likely contribution to global warming. Cheers.
94358. les at 22:57 PM on 25 February 2011
       2nd law of thermodynamics contradicts greenhouse theory
       363.... "Which is not the case at all. You are applying Kirchhoff's concept of a black body as a perfect absorber and emitter of radiation " Clearly. I was starting, as you observe, from an ideal model... always good to go back to basics - trying to clarify, at least for my self, your 'model'. which is why, in line with "and it doesn't apply in this case, GHGs in the atmosphere get nowhere near this model because no gas, in any circumstances behaves like a black body." I said that the earth and atmosphere are, indeed, not ideal black body objects. Did you actually read that?!?!? Just for clarity... 1/ no, I think it's clear the radiation is lost. end of. I said nothing of gases - I said 'object', it matters not what the object is made of (p.s. the atmosphere is a gas in a vacuum, but that's by-the-by) 2/... no. Read again they hypothetical - situation. In this highly simple model, not meant to represent the real world, but trying to clarify your 'explanation'... they are the same temp, the same surface area, same everything... except density... They would radiate and absorb the same amount of energy. simple. 3/ no it isn't. if I enclose a dense ball in a less dense shell, the shell will absorb all the radiation from the ball... where else is it going to go!?!? I am certainly not questioning the matter, nor - in general terms - the SoD model, with I rather like. But if you think his thermodynamics is amiss, I'd suggest you concentrate more on that then the e-m radiation bit... which, seems to me, you're struggling with.
94359. damorbel at 22:36 PM on 25 February 2011
       2nd law of thermodynamics contradicts greenhouse theory
       Re 362 les First you wrote:- "Clearly two bodies of the same temperature but different densities contain a different amount of energy." Then you wrote:- "Equally clearly, if they are ideal Boltzmann black bodies they will radiate the same amount of em radiation per unit area." Which is not the case at all. You are applying Kirchhoff's concept of a black body as a perfect absorber and emitter of radiation and it doesn't apply in this case, GHGs in the atmosphere get nowhere near this model because no gas, in any circumstances behaves like a black body. About your 'two extremes' 1/'free space' Really? Far too undefined; a gas in a vacuum? 2/'If, somehow, all the radiation from each was absorbed by the other, they wouldn't cool' Only if the density was the same and this is absolutely not the case for the vertical profile of the atmosphere. 3/'If the radiation from the denser was absorbed fully by the less dense' Simply impossible; see #2 From what you write 'Of course neither... ' you are clearly questioning the matter, like I am. Good luck! PS I have looked at SoD but he is far from having a good grip of the thermal characteristics of atmospheres - too much sloppy thinking.
       Moderator Response: [Daniel Bailey] If you believe SoD to be incorrect, please address that there, as SoD is well-established as an online reference tool known for accuracy in these matters. Until corrected, that status will remain.
94360. Julian Flood at 22:32 PM on 25 February 2011
       It's not us
       quote Can you explain why it would be informative to exclude some natural source and lump the remainder of the natural carbon cycle together with anthropogenic emissions? unquote Because that highlights the logic of the argument. Any increase outside the lumped-together sources can be pointed to as the cause of all of an increase. If one postulates e.g. an increase in metabolised methane from the permafrost (this is, IMHO, uncontentious as the suppression of methane efflux by acid rain is documented), or perhaps warmer deep water is increasing CO2 emissions from metabolised clathrates, then one can by the same line of reasoning say 'it's all coming from the permafrost'. This would of course be wrong, one needs to add up all the changes and then -- in this case -- one can say 'it's X Gt from permafrost and 27 Gt from fossil fuel. The proportions are X:27 and, since we don't know the absolute size of the sinks, we do not know what eliminating fossil fuel emissions will do to the rate of sink, but it will remove the CO2 in proportion to the contribution, i.e. X:27.' If we cut all of the fossil fuel emissions then we might find that the CO2 levels continue to increase because X from permafrost is bigger than the enhancement of the sink. Because we do not know the actual size of the permafrost contribution, we do not know the actual size of the sink which is taking up all but 14 Gt of the enhanced (fossil emissions + permafrost contribution). We do not know enough to make a meaningful statement. quote What is important is whether CO2 levels would be rising if not for anthropogenic emissions, and the answer is quite clearly "no, they would be falling" (which we know because the net effect of the natural environment as a whole is to absorb about half our emissions). unquote No, that is not the case. We know only that all sinks add up to more than the sum of all the sources. We do not know that CO2 levels would be falling because we have not measured the sinks and sources. See above. quote Given that CO2 levels would now be falling if we were to cut our emissions to zero, it seems odd to suggest we are not 100% responsible for the current rise. unquote No, you cannot truthfully make that assertion -- I could say 'if we cut our emissions to zero then the rate of increase of atmospheric Co2 would only diminish by 10%' and I would be talking equal nonsense. See above. This is just assertion of what we are discussing and brings us no further forward. It does point up one of the problems I'm trying to understand: if we cut to zero, would the increase in atmospheric CO2 entirely cease? My contention -- perhaps too strong a word -- my fear is that it would not. quote I have repeatedly explained that you don't need to know the value of individual fluxes to know that the natural environment as a whole is a net sink. If you shared a bank account with your partner and always put in $100 a month more than you spent, but observed your monthly balance only increased by $50 a month, you would know your partner was a net sink (to the tune of $50 a month) without needing to know where he/she spent the money, or how much he/she spent in total or how much he/she deposited each month. The mass balance argument is essentially analogous. unquote But if you have a beneficent uncle who is adding untold amounts to your account, or not, depending on how his ulcer feels, you can then say nothing about what's going on. Your daughter, meanwhile, has found a way of silently tapping off an increased allowance, and a direct debit, which you have had running so long that you'd forgotten it, has ceased. Now you do not know who is doing what because there are too many unknowns, as I have repeatedly pointed out. Unless you know the details about what's going on, you don't know what's going on and you cannot make any meaningful statement about what's going on. I agree that the mass balance argument is analogous. It is, however, incomplete in your presentation. Perhaps here we have an insight into our disagreement -- you believe that the sources and sinks are all accounted for and the only things to be considered are one input and one output, while I am not sure they are, which is why I ask these questions. My own guess is that we have screwed up one or more biological sinks, the pull down of 12C has decreased, leaving more 12C in the atmosphere, and we're misinterpreting that as part of the fossil fuel signal. But that is just a guess -- it might even be MWP deep water at last reaching the deep ocean clathrates. Or something else. However, we'll have to wait for more measurements -- only then, to continue the analogy, will we be able to look at a bank statement and see what everyone's up to. Only then will we be able to truthfully say thngs like 'if we stop emitting fossil fuel CO2 then atmospheric CO2 levels will begin to fall.'
94361. les at 21:17 PM on 25 February 2011
       2nd law of thermodynamics contradicts greenhouse theory
       361 : first, it's not "tautology because that s how you measure temperature remotely", it's a tautology because first you suggest, to paraphrase for clarity: that the em radiation is the same because the temp is the same, then you suggest that the temp is the same because the em radiation is the same. Nothing to do with measuring anything. Anyway, as you then go on to say that in fact they're exchanging "fewer photons", clearly the above is irrelevant, as I pointed out. Then, I'm sure I miss a lot in the real physics, but in this context I'm only looking at your description of how you see things. If something is missing, improve your description. e.g. in "Having a different density does not mean they cannot have the same temperature but 'the different densities' does translate directly into different amounts of energy." Clearly two bodies of the same temperature but different densities contain a different amount of energy. Equally clearly, if they are ideal Boltzmann black bodies they will radiate the same amount of em radiation per unit area. Then at two extremes there are: 1/ If both where in free space, the denser would take longer to cool than the less dense. But eventually both would cool to with a Planks whisker of absolute zero. 2/ If, somehow, all the radiation from each was absorbed by the other, they wouldn't cool. In between 3/ If the radiation from the denser was absorbed fully by the less dense, which in turn lost some energy to free space and some was radiated to the denser object, then, obviously, the amount of energy radiate into space wouldn't be going back to the denser object... it would cool - at some rate depending on it's energy density and the proportion lost in space - etc. till both where again withing a Planks whisker of absolute zero. Of course neither the earth (denser object) nor any part of the atmosphere are anything like that. They are not ideal Boltzmann black bodies. Nor are the em radiation flows so arranged... again, I recommend the SoD series to walk through the incremental complexities of reality.
94362. explorer40503 at 21:01 PM on 25 February 2011
       Monckton Myth #14: Monckton's Hunt for the H-spot Leaves me Unsatisfied
       Hi and first of kudos to all in putting this website together. I've learned a great deal reading it. Who put the circles in the first figure indicating "Even faster warming"? It seems to be pointing to the wrong part of the scale bar. Shouldn't it be closer to the .8 to 1.2 values?
94363. scaddenp at 20:51 PM on 25 February 2011
       Hockey Stick Own Goal
       HR - sorry, I missed the sensitivity calculation, skimming to fast. One other thing though - you shouldnt be just looking at NH temperatures with a global forcing. SH picture is a little different.
94364. MarkR at 19:46 PM on 25 February 2011
       Monckton Myth #14: Monckton's Hunt for the H-spot Leaves me Unsatisfied
       Thanks for the added details Chris; a lot of that is more complicated than I wanted to put here. Ultimately I think 'cooling by sweating' is a perfectly good analogy. If you construct the energy balance at the surface then it's the latent heat transfer that ultimately leads to the 'hot spot'. I looked at some papers discussing the difference in water vapour content vs precip, and there are some long term series suggesting the walker circulation has weakened which is one of the predictions of how to decouple precip from the C-C response... but again, I thought this was too complex and off topic to cover here. The WV+LR interdependence was why I said my above calculation of how to cut warming by a factor of 4 is 'so far wrong I refuse to believe that's how Lindzen did it'.
94365. damorbel at 19:42 PM on 25 February 2011
       2nd law of thermodynamics contradicts greenhouse theory
       Re 360 les You wrote:- "The temperatures are the same because the energies of the photons from both sources are the same;" is a tautology " Indeed it is a tautology because that s how you measure temperature remotely Then you wrote:- "So, two 'bodies', sufficiently identical to emit the same amount and spectrum of e-m radiation, and, we assume, the same absorptivity, so they identically absorb the energy will, by definition" And "Clearly, without interpretation, implies that no energy is escaping to space or any where else" "no energy is escaping"? That is not the case, the upper atmosphere (UA) is less dense than the surface and will exchange fewer photons with the lower atmospheric layers (and the surface) than pass through (the UA) on their way into space. Having a different density does not mean they cannot have the same temperature but 'the different densities' does translate directly into different amounts of energy. What you are missing is the fact that, with a uniform temperature, the lower atmosphere exchange photons but without any change in their relative energy.
94366. les at 19:10 PM on 25 February 2011
       2nd law of thermodynamics contradicts greenhouse theory
       358 damorbel: Clearly that's what I said - and for good reason. Given (for the sake of argument): 1/ "Let us imagine for a moment that the surface and the upper atmosphere are at the same temperature. In this situation both surface and the UA are emitting photons with the same energy" and the assumption it requires... Then, this 2/ "The temperatures are the same because the energies of the photons from both sources are the same;" is a tautology - The spectrum of photons energies would be the same if the temperature, emissivity etc. are the same (said assumptions) - and we ignore it. So, two 'bodies', sufficiently identical to emit the same amount and spectrum of e-m radiation, and, we assume, the same absorptivity, so they identically absorb the energy will, by definition 3/ "there would be thermal equilibrium i.e. no energy transfer and no temperature change." Clearly, without interpretation, implies that no energy is escaping to space or any where else. You couldn't possibly mean that the surface is being headed by anything, like the sun, because you would have said so. yet in your "real" model: "bla bla... it is further radiated into deep space." QED. But really the problem is that you have given a qualitative description of how you feel things work and this leaves the door open to a range of errors - whether interpretation on one side, missing assumptions or just poor physics on the other. As SoD has shown, it is completely possible to build up mathematical models to describe how this works. If someone doesn't agree, the thing to do is present either alternative maths or, at least, show which assumptions or derivations are wrong in the original.
94367. damorbel at 18:54 PM on 25 February 2011
       2nd law of thermodynamics contradicts greenhouse theory
       Re 352 KR You wrote:- "First - Do you think thermal emission is monochromatic? " No. "Second - Absorptivity describes.... ...ground, for example, has about a 95% probability of absorbing a photon at 6 micron wavelength." Probably. Further you wrote:- "The thing is, photons do not carry ID cards" They certainly do. The energy of a photon is E = hv where 'h' is Planck's constant and 'v' is the source frequency. I suggest you check a book on thermal radiation before responding on this, you are clearly lost on this one. And further you wrote:- "So your statement "The temperatures are the same because the energies of the photons from both sources are the same" is incorrect. The sun provides... " Please check my 350; I was writng about an isothermal atmosphere, one with a uniform (vertical) temperature distribution. I didn't mention the Sun because I was on about atmospheric radiation: in an isothermal atmosphere there is no heat transfer of any sort because heat transport only happens with a temperature difference - standard 2nd law of thermodynamics - don't you think?
94368. damorbel at 18:40 PM on 25 February 2011
       2nd law of thermodynamics contradicts greenhouse theory
       Re 357 les You wrote:- "I was alluding to 350 damorbel (where one moment all the radiation is returning to earth and the next it's radiating to space)" No les, that's what you said, not me. I agree it isn't right but of course it's your interpretation, not what I said.
94369. Tom Curtis at 17:37 PM on 25 February 2011
       Hockey Stick Own Goal
       muoncounter @117, response here.
94370. Tom Curtis at 17:36 PM on 25 February 2011
       A detailed look at galactic cosmic rays
       Responding to Muoncounter: ""may be a connection between low solar activity and lack of major volcanoes, ... may also be an impact of galactic cosmic rays, ... on cloud albedo." They're way off topic, but those are new ones on me. If you can find an appropriate thread, care to explain?" This is just a speculative thought of mine about Svenmark's hypothesis. My first thought when I heard Svenmark's hypothesis is exactly described by El @14 above. There is an abundance of Cloud Condensation Nuclei, particularly over ocean (salt from sea spray), desert (dust) and forest (aramotic compounds released from leaves). Adding one more source of CCN is therefore unlikely to increase cloud cover. However, adding additional CCN is known to reduce the average droplet size within clouds. This can be seen most easily in ship tracks: It is also a known effect of industrial polution, with clouds downwind of cities typically having smaller than usual droplet size. (This does not get much discussion when deniers discuss the Urban Heat Island effect, and surface station placement, for reasons that will become obvious.) Decreasing cloud droplet size has two effects. It decreases the probability of rain, and it increases the albedo of the cloud. The former may result in longer lasting clouds, but if humidity drops, it is unlikely to compensate for the faster evaporation due to the increased surface area per unit volume from smaller droplet size. However, the increased albedo is real, detectable, and will have a cooling effect. So, assuming that Svenmaark is right in claiming that GCMs form CCN, and he has at least mounted a plausible case, then increased GCMs will increase cloud albedo by a small amount. It is obviously not a large amount because, if it were, the effect would be very obvious in the temperature record as a strong correlation between temperature and Sun Spot Number. But it may explain the small correlation seen between temperature and SSN surface temperatures, and some of the correlation between deep solar minima and cool temperatures which far excede the ability of TSI changes to explain.
94371. Chris Colose at 17:12 PM on 25 February 2011
       Monckton Myth #14: Monckton's Hunt for the H-spot Leaves me Unsatisfied
       I wish I seen these posts prior to submission but I guess I can use the comments to clarify some matters. I'd do my own post here but I think the hotspot issues are starting to exhaust themselves on the blogs. A rather robust response in global warming simulations is that toward the surface, the pole-to-equator temperature gradient is decreased, and at higher altitudes, the gradient is increased. From the perspective of a vertical-cross section, the temperature tends to be enhanced near the surface in the polar regions and in the upper atmosphere in the tropics (as Fig.1 shows in this post). This behavior as a wide range of dynamic implications, and while it may not be the best behavior to look at for linking GHG's to climate change, much of the literature on responses to climate change (for example, precipitation impacts or hurricane activity) relies closely on the moist stability of the tropics. In the tropics, the coriolis effect is weak and the result is that waves and mixing maintain (roughly) a horizontally uniform temperature profile over the entire tropics (gravity waves spread heat pretty efficiently over an extremely large Rossby radius). In the deep convecting regions, the atmosphere adjusts to stay rather close to the moist adiabat (which is determined by the moisture content in the boundary layer). In non-convecting regions, the free-tropospheric temperatures must also be close to the same moist adiabat. The moist adiabatic lapse rate is not an esoteric concept-- it's just the rate at which temperature declines with height in an atmosphere where you have the typical effects of gas expansion at lower pressure but also a condensing gas releasing its latent heat. The moist adiabatic lapse rate is not a constant value, but is related to the way the saturation vapor pressure increases with temperature (which is not linear). It is easy to show that the steepness of the moist adiabat declines in a warmer atmosphere. See e.g. http://en.wikipedia.org/wiki/File:Emagram.GIF The dashed lines are the slopes of interest, which become roughly dry adiabatic at very cold temperatures and shallow out at warmer temperatures. The amount of latent heat released by condensation by a saturated parcel that moves up the atmospheric column depends on the temperature, which is increased slightly for warmer starting conditions, so the effect is to have enhanced atmospheric warming relative to the surface. Thus the temperature signal discussed in the post doesn't necessarily imply increased “convective activity” or evaporation, but a reduction in lapse rates. The reason the lapse rate feedback is negative is because a warmer parcel of air can radiate more efficiently than a colder one, so the planet can radiate away more from middle atmospheric layers than from the surface (compared to a case with no amplification aloft), which implies a cooler surface temperature. The lapse rate itself is intimately tied to the way the greenhouse effect works. The infrared absorption is only half the story, you need the right vertical profile to get a strong greenhouse effect, and inversions (for example in Antarctica or during the winter in a snowball Earth where there is little convection) can inhibit the ability for GHG's to do much. Regarding Monckton's claim about evaporation, it's usually tough to make sense of anything he says. There's absolutely no clear cut indication the models are doing anything systematically worng with respect to evaporation anyway. There's some studies which suggest global precipitation might be increasing faster than models (starting from Wentz et al 2007 I think), but like the tropical hotspot issue, is an issue that is data problematic...I've also not seen any work that connects this to climate sensitivity at all. In any case, over moist surfaces, what evaporation does is make the surface energy budget "stiff" so that the surface temperature does not deviate substantially from the overlying air temperature. It comes out that the top of the atmosphere energy balance rules the roost in determining the maximum allowed temperature. It should also be noted that theoretical exercises that respect the surface energy budget (or sometimes the tropospheric energy budget), as well as GCMs, indicate that evaporation (and precipitation) increase much less rapidly than the the water vapor actually in the atmosphere (which scales with the Clausius-Clapeyron equation). It's the water vapor content that stays in the atmosphere that determines the water vapor feedback, which itself has little to do with the increase in evaporative flux from the surface. In fact, evaporation could easily decrease in a warmer climate if the wind speeds were to reduce, or if you somehow turned down the solar radiation but kept the temperature increasing (say, by increasing GHG's). Finally, the water vapor feedback is not independent of the strength of the lapse rate feedback. The two feedbacks are connected, so feedback specialists usually talk about a water vapor+lapse rate combined feedback, and the uncertainty in the combined term is less than the individual uncertainties in the individual feedbacks.
94372. muoncounter at 15:42 PM on 25 February 2011
       Hockey Stick Own Goal
       Tom, "may be a connection between low solar activity and lack of major volcanoes, ... may also be an impact of galactic cosmic rays, ... on cloud albedo." They're way off topic, but those are new ones on me. If you can find an appropriate thread, care to explain?
94373. pbjamm at 15:42 PM on 25 February 2011
       Meet The Denominator
       Poptech@719 My argument continues and has always been that only a small fraction of these explicitly endorse "anthropogenic global warming". ===== What exactly is required for research to explicitly endorse AGW? Is it enough that the findings of a study consistent with predicted effects of AGW? Do the researchers have to state that it is consistent with AGW? Do they have to say the results are due to AGW? Just like with your AGW Alarm refrain, only you know what the subjective criteria are. PS - Your scare quotes around anthropogenic global warming make it difficult to take you seriously.
94374. Alex C at 15:35 PM on 25 February 2011
       Monckton Myth #14: Monckton's Hunt for the H-spot Leaves me Unsatisfied
       Thanks for the reply Mark and for trying to follow through. I read Things Break's post (well, the copy here) too and noted the striking similarities (and striking hot spots) in those circumstances. I think that it does clearly show the expected response due to increased forcing, though perhaps the figure above does not so much, as the model output is based not on an assumed 2% increase in solar output but the increase measured over the past century. I'm curious though, this fourfold figure came from Lindzen? I had assumed it was one of Monckton's conjurings as he was the one quoted saying it above, and it doesn't seem as though Lindzen is mentioned in the article.
94375. scaddenp at 15:06 PM on 25 February 2011
       CO2 lags temperature
       Responding from here The newtonian gravity situation is an n-body body, so quite definitely deterministic chaos. However, the milankovitch cycles are predictable, regular cycles at the time scales we are talking about (whether you could extend 100my back is entirely different). However, what you think of a chaotic signal is not - the spectral analysis gives that away. Set up a spreadsheet with =R*sin(a*A1]) + S*sin(b*A1) + T*sin(c*A1) where R,S,T are within an order of magnitude and a,b and c are not multiples of each other, and you get an utterly non-chaotic,predictably cycle but no repeats.
94376. Tom Curtis at 14:56 PM on 25 February 2011
       Hockey Stick Own Goal
       scaddenp @114, HR is allowing for feedbacks in his comment; hence his attempt to caclulate rough climate sensitivities.
94377. Tom Curtis at 14:55 PM on 25 February 2011
       Hockey Stick Own Goal
       (Sorry, my line went down as I was submitting my comment @115. Here is the full version.) HR @113: First, there is nothing wrong with allowing the change in forcings but keeping Husserl's reconstruction. The reconstruction was made independently of estimates of forcings, and based on long series proxies. Second, your back of the envelope calculations ignores the other forcings. Of these, the most important in the MWP is the volcanic forcing, which was three times stronger than solar forcing during that period. Based on laying a ruler against Fig 5 a (after blowing it up 750%), the respective forcings are approximately: Volcanic 0.5 w/m^2; solar 0.2 w/m^2; GHG + Aerosol -0.1 w/m^2. (Note, I have used the temperature scale the other forcings against the reported solar forcing.) Plugging those figures into the back of envelope calculations we get a climate sensitivity approx = (0.7/0.6)*3.7 = 4.3 If we then scale back the solar contribution based on Gray's estimates, the net mean MWP forcing is between and 0.45 and 0.5 w/m^2, for a forcing response of between 5.2 and 5.8 Note that these are probably significant over estimates on the data as I have used the average of Lundqvist's total variation (as given by you) instead of calculating a specific MWP variation. Using the probably more reasonable figure for just the MWP of 0.4 reduces the range to from 3 to 3.3 - hardly a problem for the IPCC. These values are so loosely calculated as to be effectively worthless - I would not trust them to do more than indicate the order of magnitude of the expected effect. But they do show that you cannot simply ignore the non-solar forcings. Even if you do, your calculated values are not out of the IPCC ball park as calculated using temperature and forcing reconstructions of the last century. According to AR4, the sensitivity has a probability of around 66% of falling between 1.5 and 6.5 (from eyeballing the chart above) on that data, and a 99% probability of falling between 1 and 9. So, once again I conclude that you have not shown there to be any problem with climate sensitivities given the limitations of the data. Finally, it is not clear that there is a distinct correlation between temperatures and TSI. Notoriously, such a link has been hard to pin down in the 20th century with regard to the sunspot cycle. Of four reconstructions examined by Husserl 2007, only 1 shows a detectable solar signal, and two show very slight negative correlations with TSI once other forcings have been removed from the signal (or at least require negative scaling factors). The apparent correlation seems to be based in part on periods of intense volcanic activity coinciding with certain solar minimuma, along with a feedback based on increased solubility of CO2 in the oceans with declining temperatures. There may be a connection between low solar activity and lack of major volcanoes, presumably based on the interactions of the Sun and Earth's magnetic fields modifying the length of the day. There may also be an impact of galactic cosmic rays, not on cloud extent (which as been effectively falsified) but on cloud albedo. But these connections are tenuous and, on current evidence, speculative. These may be fruitful avenues of research but because the connections are so unclear on current data, it is highly unlikely that the end result of such research will make major changes to the current (IPCC) understanding of what drives climate. This is especially true as, in anything, current estimates of TSI are to low to fully explain even that weak effect of solar variation that is detectable.
94378. KR at 14:53 PM on 25 February 2011
       Climate sensitivity is low
       RW1 - The answer is not "no", it is "in part". I've (repeatedly) clearly answered your question - narrowing of the atmospheric window is part of the 3.7 W/m^2, and deepening of the intercepted bands due to higher effective emission altitude is also part of the 3.7 W/m^2. It's not an either/or question!
94379. scaddenp at 13:57 PM on 25 February 2011
       Hockey Stick Own Goal
       "TSI changes correlate well with temp change over this period. But the magnitude of TSI is too small to account for the change." That would be what feedback is all about. Any change in T affects water vapour for starters, magnifying the forcing whatever its source.
94380. RW1 at 13:52 PM on 25 February 2011
       Climate sensitivity is low
       By 'atmospheric window', I'm referring to the amount of the emitted surface power that passes through the atmosphere completely unabsorbed by GHGs or clouds.
94381. scaddenp at 13:51 PM on 25 February 2011
       Climate sensitivity is low
       RW1 - actually that's what I dont understand. What do you mean by "atmosphere window"? A clearer understanding of that might illuminate this.
94382. RW1 at 13:05 PM on 25 February 2011
       Climate sensitivity is low
       KR (RE: 117), Then the answer is no. What's so hard to understand here? I'm trying to find specifically where the disagreement lies. This is pretty basic stuff.
94383. Lazarus at 13:01 PM on 25 February 2011
       Motl-ey Cruel
       I would consider getting banned from a trash site like that a badge of honour.
       Moderator Response: [Daniel Bailey] This thread is, in Dikran Marsupial's words, "Sailing too close to the wind". Let's all return to the topic of the thread and tone down the invective a bit. Constructive criticism is fine (when it complies with the Comments Policy, anyway). Thanks!
94384. RW1 at 12:52 PM on 25 February 2011
       Climate sensitivity is low
       KR, Let's take this one question at a time. What does the atmospheric window represent? Please define it for me.
94385. KR at 12:31 PM on 25 February 2011
       Climate sensitivity is low
       RW1 - "The estimated 3.7 W/m^2 from 2xCO2 either represents a reduction in the atmospheric window or not." Wrong. It's partially a reduction in the "window", and partially a reduction, a drop in the intensity, in the GHG bands - the ones already inhibited by the presence of greenhouse gases. Not yes or now, but "in part". As GHG concentration rises, the effective emission altitude goes higher and higher in the troposphere, and hence (due to the lapse rate) comes out of colder and colder GHG's. They emit less than warmer lower GHG's - the additional altitude means that the repeated reduction in IR transmission as part gets emitted up (to higher levels) and parts down attenuate the IR levels. That and widening bands, the reduction of the window, combine to provide the 3.7 W/m^2 effect from doubling CO2. That is why I gave a nuanced answer, one that actually answered your question without conveying incorrect information. It's not A or B - it's both.
94386. RW1 at 12:23 PM on 25 February 2011
       Climate sensitivity is low
       KR, The actual number for the atmospheric window is irrelevant to the particular question at hand here. Whether it's 40 W/m^2 or 90 W/m^2 - it doesn't matter, nor do I care. The estimated 3.7 W/m^2 from 2xCO2 either represents a reduction in the atmospheric window or not. The fact you seem to be side stepping this fundamental question is quite revealing. It's a ridiculously simple and straightforward question with a simple yes or no answer. I can see no one here is interested in getting to bottom of this, so it appears like I'll have to do some more searching around and figure out for myself.
94387. Rob Honeycutt at 12:13 PM on 25 February 2011
       Meet The Denominator
       Poptech... Look, there are 10's of thousands of papers coming out on climate change every year now. Do you think they're all just because people are curious what the weather is going to be like? This is a huge area of research because of... guess what... the anthropogenic nature of climate change. Why is there so much work in this area? People are "alarmed" about the potential consequences. All the papers coming out are about "AGW alarm."
94388. Stu at 11:53 AM on 25 February 2011
       Motl-ey Cruel
       Shawn, My first guess would be continental configuration.
94389. KR at 11:53 AM on 25 February 2011
       Climate sensitivity is low
       RW1 - The answers to your four questions are "Yes, ~40 W/m^2", "Yes, although a fair amount of energy also goes into the atmosphere via convection and latent heat (~20%)", "Only partially", and "Almost, it's the amount prevented from leaving via various effects - more absorption and higher/colder emissions". Sorry, but these are obviously important questions for you, and I would be doing a disservice by giving un-nuanced answers.
94390. shalayka at 11:49 AM on 25 February 2011
       Motl-ey Cruel
       scaddenp, Thank you for the information. I can agree that the intensity of sunlight has a lot to do with how warm it is on Earth. :) My main concern is that no ice age is ever the same as the previous one. As you know, Henon studied something superficially similar when he did his work on modeling the orbits of stars in galaxies. As far as I know, Henon used Newtonian gravitation, and so his model galaxy is as deterministic and static as Milankovitch's solar system. Of course, the model galaxy's stars never follow the exact same path twice, though they do stay roughly along the galactic plane. This is deterministic chaos in action. So I ask earnestly... what is the name of the cause behind the fact that the glacial/CO2 cycles are roughly regular (like a galactic orbit), but never the same (like a galactic orbit)? This is something that I have not really got a satisfactory answer to, from either polluters or treehuggers. - Shawn
       Moderator Response: [muoncounter] Your question is addressed on the CO2 lags temperature thread, specifically here. I'm not at all sure why you feel these cycles should all be the same, nor why there is a single name (ie, a single cause?) for these similarities/differences. Subsequent comments should go to that thread.
94391. Andy Skuce at 11:48 AM on 25 February 2011
       Carbon Cycle Feedbacks
       Hugh@7: the comment you referred to says that the trees were burned by a prescribed fire. On the other hand, this Wikipedia caption to the same picture says Invaded pine tree forest on the slopes of Chancellor Peak in Yoho National Park, Canada. The two comments are not contradictory since Parks Canada has adopted a policy of prescribed burns to manage the beetle infestations. I should add that climate change is not the only factor influencing pine beetle outbreaks, forest management practices, especially fire suppression in the twentieth century, have played a major role. In case anyone is curious, here's a map showing the location of Chancellor Peak and the areas susceptible to pine beetle outbreaks in three of the Canadian Rocky Mountain Parks. According to the BC Ministry of Forests, 16.3 million hectares of forest have been affected by pine beetle infestations. That's roughly the area of Austria and the Czech Republic combined. Map here.
94392. HumanityRules at 11:42 AM on 25 February 2011
       Hockey Stick Own Goal
       Tom Curtis OK thanks I hadn't gone back so far in the literature to estimates that were as high as Crowley's and I was working on the basis of the other Hegerl paper where the references were for Lean solar forcings (around 3). That seems to fit with the papers I'd been reading. You wrote "Hence your previously stated concern that the new evidence on solar forcings might require climate scientists to adopt unphyscical climate sensitivities to explain the past is unwarranted." But you've now done the opposite to what Dana did in the post. You've allowed for the changing understanding of solar forcing but have kept Hegerl's temperature reconstructions. I'll have a stab at back of the envelope calculations. Gray's estimates of changes in solar forcing on centennial/millenial time scales 0.16-0.28 Wm-2 Natural temperature variability from Fig1 (MWP to MM). I'll be generous at 0.4oC (but I think Ljundquist is maybe 0.6-0.8). Lowest Climate sensitivity based on these numbers = (0.4/0.28)*3.7= 5.3 Highest Climate sensitivity based on these numbers =(0.4/0.16)*3.7= 9.25 (I have no idea if that's how you do the calculation, I'm wearing my flak jacket) Both these numbers are outside the IPCC best guess at climate sensitivity and as I said I think I'm being generous with the temperature variability. The numbers can get even worse. The STEINHILBER reference in #54 has MM to present solar forcing of <0.1. MWP to MM is probably the same (the data and readme file if you want to play with them). Those numbers go beyond problematic and start to get unphysical. I think you only keep the IPCC favoured range within the error bars if you retain the lower deltaT reconstructions (early Mann and others) or higher deltaTSI estimates (Lean). If you do that you get wider error bars, I think the IPCC has been working to reduce them. However you approach this it's problematic for the concensus view. "Neither techiques for reconstructing past forcings or past temperatures are sufficiently exact to tightly constrain climate sensitivity" Look I take your caveat on board. But the science is supposed to have evolved, it's meant to be better now than it was in 1998-2000. If you're making this arguement now in 2011 what should we (or the IPCC) have been saying in 2007 or 2003? It's the IPCC that's suggesting this type of data is supporting evidence for AGW. So is it or isn't it? (An unrelated question I have from reading the literature. TSI changes correlate well with temp change over this period. But the magnitude of TSI is too small to account for the change. Doesn't this open up the possibility that there's a big hole in our understanding of solar-climate interactions? I know there are controversial ideas about other solar mechanism for changeing the climate and it's probably not right to discuss those on this thread. But isn't all this demanding higher solar forcing and that coming from somewhere other than direct changes in solar energy output?)
94393. RW1 at 11:17 AM on 25 February 2011
       Climate sensitivity is low
       scaddenp, I'll break it down into a series of separate small questions: 1. Do you agree that some of the emitted surface infrared power passes through the atmosphere unabsorbed by GHGs or clouds? 2. Do agree that the remainder is absorbed by the atmosphere? 3. Does the 3.7 W/m^2 of 'radiative forcing' represent a reduction in the atmospheric window of 3.7 W/m^2? 4. Does the 3.7 W/m^2 of 'radiative forcing' represent an increase of 3.7 W/m^2 in the amount of infrared absorbed by the atmosphere. My understanding is your answer to 1 & 2 is YES and your answer to 3 & 4 is NO. Is this correct?
94394. scaddenp at 10:55 AM on 25 February 2011
       CO2 lags temperature
       The 100,000 cycle is problematic. See here for some more discussion. I'd say the jury is till out.
94395. scaddenp at 10:52 AM on 25 February 2011
       Motl-ey Cruel
       Shalayka - ice age cycle is not chaotic. Do spectral analysis and you see instead that is the sum of the milanvokitch cycles. Not the pattern of a chaotic attractor. Look at series here to see this but easy enough to repeat yourself.
94396. scaddenp at 10:45 AM on 25 February 2011
       Models are unreliable
       I would say that models have reliably predicted global climate trends(but not weather) in that observed climate variable have tracked prediction within the bounds of uncertainty. Is that useful? They are telling you it will be expensive implications if GHGs continue to be emitted at current rate. Sounds a useful prediction to me.
94397. scaddenp at 10:39 AM on 25 February 2011
       Climate sensitivity is low
       RW1 - "You are saying the 3.7 W/m^2 increase is not the reduction in the atmospheric window? " Hmm, but we have this rather odd expression about "reduction in the atmosphere window". What does this mean? KR identifies it with a GW idea. Can you phrase the question in a way that we can understand, and preferably makes physical sense?
94398. mothincarnate at 10:37 AM on 25 February 2011
       Meet The Denominator
       I suppose I should also mention from experience, that Andrew (aka Poptech) seems committed to the validity of his list beyond all reason. One can point out that others have demonstrated flaws in this or that paper, but he'll reply that the others are 'alarmists' or that certain papers don't actually question the reality of AGW, but he will then start talking about 'AGW alarm' or ask his about AGW Observer, but he will just ignore you, or point out that Monckton has been demonstrated wrong on numerous occasions and even if not, an article about free speech in AGW doesn't counter science literature, he'll wash his hands of responsibility, or point out duplicates, non-science journals etc etc etc: but as you can see in this comment thread, Poptech goes on and on.. His personal research, in his mind, stands up against a large qualified scientific community with many people-centuries of research. Such people define the meaning of "unreasonable" beautifully.
94399. mothincarnate at 10:23 AM on 25 February 2011
       Meet The Denominator
       JMurphy, I had directly cut-and-pasted a comment thrown at me by an advocate of Poptech's silly list (spelling mistakes left for added hilarity - the character "indulges" in "humouring" and educating me, whilst continually demonstrating really basic spelling errors). I don't personally think that demanding the other to "debunk all these papers" is logical - hell, that's what the science community already does. But I am surprised that Poptech and his fan "Adam" (whom I'm quoting) and many others really think Poptech's list means anything.. But then again, they also support Monckton...
94400. MarkR at 10:14 AM on 25 February 2011
       Monckton Myth #14: Monckton's Hunt for the H-spot Leaves me Unsatisfied
       Alex C: The model 'guess' is a reasonable one if you're not at all familiar with the models. Thankfully RC put up the effect of a 2% solar increase and it shows it very clearly: h/t to thingsbreak's post here. I've emailed Lindzen to ask how he calculated the fourfold response, I'm stumped. Perhaps he used a more complicated model, but there's not much point me running through more complex models until I know there's an answer there. I've wasted enough time doing detailed checks of 'facts' quoted as evidence against AGW that I think the onus is definitely on the accuser to support their point now.

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