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

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Comments 94451 to 94500:

  1. 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'.
  2. 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.
  3. 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.
  4. 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?
  5. 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.
  6. Hockey Stick Own Goal
    muoncounter @117, response here.
  7. 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.
  8. 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.
  9. 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?
  10. 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.
  11. 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.
  12. 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.
  13. Hockey Stick Own Goal
    scaddenp @114, HR is allowing for feedbacks in his comment; hence his attempt to caclulate rough climate sensitivities.
  14. 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.
  15. 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!
  16. 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.
  17. 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.
  18. 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.
  19. 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.
  20. 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!
  21. 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.
  22. 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.
  23. 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.
  24. 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."
  25. Motl-ey Cruel
    Shawn, My first guess would be continental configuration.
  26. 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.
  27. 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.
  28. 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.
  29. 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?)
  30. 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?
  31. CO2 lags temperature
    The 100,000 cycle is problematic. See here for some more discussion. I'd say the jury is till out.
  32. 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.
  33. 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.
  34. 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?
  35. 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.
  36. 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...
  37. 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.
  38. Hockey Stick Own Goal
    Yes, definitely human. Last time I checked, anyway.
  39. Monckton Myth #14: Monckton's Hunt for the H-spot Leaves me Unsatisfied
    Alex: I think I know how you can massage out that 'fourfold' figure. Assume that the IPCC climate sensitivity is 4.5 C. Therefore the climate feedback parameter (definition here) = 3.7/3 = 0.8. If you look at the Soden and Held values can be seen in a graph here then pick the highest estimated lapse rate feedback (~-1.2) and treble it then you get a feedback factor of 3.2. This makes your climate sensitivity = 3.7/3.2 = 1.1-1.2 K and yes, you've almost cut the value to a quarter. That's one way of doing it, but it's so far wrong I refuse to believe that's how Lindzen did it... so I'm going to try and find out how he did. It's the sort of thing that would turn up on WUWT.
  40. Climate sensitivity is low
    @ #111 "No, the problem is no one is answering my question. Or perhaps its just not the answer you want to hear.
  41. Climate sensitivity is low
    KR, My question isn't related to what the number for the window is. scaddenp, No, the problem is no one is answering my question.
  42. Dispelling two myths about the tropospheric hot spot
    ClimateWatcher @12, Are those the trends from 1979 through 2006? It would be nice to have data up until and including 2010. One can see the polar amplification (a predicted consequence of a warming planet) over the Arctic nicely in most datasets. IMHO, one of the problems in identifying the elusive tropical "hot spot" is that it is expected to be close to the tropopause, and that is especially problematic for the coarse satellite data.
  43. How We Know Recent Global Warming Is Not Natural
    95 Fixtures23, Oh my! Welcome to the site, the folks here are very open-minded and love discussing science. I see JMurphy has already suggested that you visit the "Newcomers Start Here", "The Big Picture" and Most Used Skeptic Arguments". Also, be sure to check the comments policy. I think you will find them very helpful. Cheers!
  44. CO2 lags temperature
    Tell me if I have this right... The 100,000 Milankovitch Cycles are the result of eccentricity of the Earth's orbit. So, interglacial periods, like the present, occur when the planet is closer to the sun.
  45. Dispelling two myths about the tropospheric hot spot
    "So, does the hot spot actually exist?" No. I did this check four years ago: Upper Left: NASA GISS Model through 2006 Lower Left: RATPAC Raob data through 2006 Upper Right: UAH MSU (LT, MT, LS) through 2006 Lower Right: RSS MSU (LT, MT, LS) through 2006
    Moderator Response: [Daniel Bailey] Fixed image HTML tag.
  46. How We Know Recent Global Warming Is Not Natural
    Wow, fixtures23, you could do with some reading on some of those claims you are making - quite the Gish gallop, eh ? For your enlightenment and further education try these links : Newcomers Start Here The Big Picture Most Used Skeptic Arguments That should help you become more aware of the facts. As for Popular Technology, trawl your way through this link and see what you are aligning yourself with. By the way, where did you get all that false information from in the first place ?
  47. Motl-ey Cruel
    Dana, I know it can be upsetting to be verbally attacked by someone, but don't let it get you down. When someone attacks me personally, I generally smirk and make popcorn. I was only trying to heckle you for your loose language. You're otherwise clear in your writing, and so it's obvious to everyone that you're not actually illiterate or anything of the sort. I had a right to be ticked off at Acton last year, specifically because of his loose language that made it seem like CRU couldn't release their data because Canada's some kind of a draconian datapig. So, I do get a little testy when I see people beaking off about climate science. Anyway, please don't put me on your list of deniers quite yet. I shovel snow for a living, and so I'll be my own judge, in due time. For what it's worth, I'm crazy enough to believe that chaos exists in the ice age cycle. I mean, it's cyclical, but never ever exactly repetitive. Sounds like the work of a chaotic attractor to me -- an idea that I can guarantee that Lubos Motl would think is naive. So please don't think of me or anyone in particular as part of a Motl-ey crew. That's way too black and white a model of reality. Shawn Halayka
  48. Motl-ey Cruel
    since starting to research the subject of Global Warming/Climate Change a couple of months ago I have visited a good few websites and blogs and have found that even without a scientific background it is remarkably easy to judge whether a site is likely to yield any good information or is simply a front for some vested interest or inflamed ego. I started with an open mind but very quickly realised that the sites that openly discussed the issues and the science were those that accepted AGW as fact. Most 'denier' sites seem to be a triumph of (poor) style over substance. This site may be about the science, but it is the willingness to discuss the facts and engage with the contrarian view however tedious that make it work and worthwhile
  49. How We Know Recent Global Warming Is Not Natural
    The evidence that the climate is being changed by man does not exist. The IPCC predicted an average trend of 3.9celsius/century from theoretical computer models. these models are not based on observations. they respond to what the modeller puts in to them(not very scientific) However actual satellite observations from the RSS and UAH satellite data sets show this trend to be a mere 0.3celsius/century(see SPPI global temperature data index.) Since coming out of the Little Ice Age in 1850 it is to be expected that there would be some warming. however the rate of warming in the second half of the 20th century has been exactly the same as the rate of warming 1918-1940 when clearly human carbon dioxide could not possibily have been the cause.One must consider all of geological time not the small 130 years of the instrument record. This geological record shows for example the MWP(Medieval Warm Period 950-1300) to be four degrees warmer than today. Pollen samples taken from Baffin Island also show that temperatures 5000 years ago were five degrees warmer than today. the alarmists are wrong! As for numbers Dr Spencer and Professor Lindzen are in good company. In fact Dr Art Robinson has listed over 31 000 graduate scientists including over 9000 PHds who reject antropogenic global warming as responsible for climate change.(see www.petitionproject.com) Also populartechnology.net/2009/10/peer-reviewed----------html lists 850 peer reviewed scientific papers who all reject AGW as the cause of climate change.
    Moderator Response: [Daniel Bailey] Welcome to Skeptical Science! There is an immense amount of reference material discussed here and it can be a bit difficult at first to find an answer to your questions. That's why we recommend that newcomers do as JMurphy has just suggested to you below. I also recommend watching this video on why CO2 is the biggest climate control knob in Earth's history. Further general questions can usually be be answered by first using the Search function in the upper left of every Skeptical Science page to see if there is already a post on it (given the plethora of posts [I get paid extra for using big words and alliteration :-) ] odds are, there is). Or you can search by Taxonomy. When you have questions, please post them on the most appropriate thread. Remember to use the Preview function (avoids html tag errors) and to construct your comments in compliance with the Comments Policy. I'm afraid the vast majority of your comment is simply incorrect. The warming of the globe is an accepted fact. That humans are causing a good part of it is accepted at over a 90% scientific certainty level. Only the anthropogenic contribution (which did not exist in the paleo record) completes the picture, explaining the warming we can empirically see and measure in the absence of other forcings. Else we would be measuring a decades-long cooling trend. Which we aren't: Forcings, except for CO2, have been flat for nearly 40 years. Temperatures continue to climb, and that rate of climb is still increasing (as are CO2 levels).
  50. Models are unreliable
    Dikran Marsupial at 20:45 PM on 24 February, 2011, re "Large uncertainty does not imply unreliability. In fact it means that models are more likely to be reliable as the model projections cover a wider range of possibilities." Whilst that may satisfy the academics, the question that arises for those looking for something worthwhile to work with, is at what point is any usefulness lost? As an example, in Australia, BOM and CSIRO found the secret to increasing realibility of their medium to long term forecasts was by issuing them in terms such as one frequently offered "there is a 50% chance of above average rainfall". The classic however was a seasonal forecast of a 40% chance of above average rainfall. However, as is painfully obvious, but as was also observed in a recent Parliamentary inquiry, such forecasts are somewhat less than useful. Reliability is meaningless if it has been gained at the expense of usefulness.

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