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Gilles at 22:31 PM on 14 April 2011The e-mail 'scandal' travesty in misquoting Trenberth on
Sorry, DB, but I don't see where I've been incorrect. I'm only answering Alec's remarks directed to me. -
Gilles at 22:21 PM on 14 April 2011The e-mail 'scandal' travesty in misquoting Trenberth on
Alec#104. Again , what are you're arguing? that energy must be conserved? of course it must ! did I deny that ? I said that when Trenberth said that they couldn't explain the lack of warming, he meant that there was a lack of warming, and that he couldn't explain it. Again, it's extremely simple : he said what he meant. Now you're saying : oh but other people have suggested that it could be due to heat storage in the deep ocean - well of course this is a *possible* explanation. But to my knowledge, there isn't precise measurements of the heat content of deep oceans. So it is only one of the possible explanation - another obvious one being that the global imbalance used is wrong. You seem to mix up suggestions with explanations. ( -Snip- )Moderator Response: [DB] Cease with making things personal. You are simply incorrect, yet incapable of admitting so. Most would regard that flaw as a failing. -
daniel maris at 22:17 PM on 14 April 2011Monckton Myth #16: Bizarro World Sea Level
Dikran, I am a little suspicious of your approach - it seems like reverse trolling. Presumably you have read these papers that you recommend I take the time to read, although I have never claimed to be trained in this area. Presumably you could sum things up pretty pithily. Presumably you could say some specific things like "That tree in Morner's photograph is no evidence because..." But you choose not to. Instead you send me off to read hundreds of pages of scientific analysis. My view of the subject is based on (1) Knowing that any effects of sea level rise in the south of the UK (which in any case is sinking) have been manageable (2) As far as I know, no one has been able to point to an island in a stable area (i.e. not an area where the land is sinking or in a delta) that has gone under water in the last 100 years. I'd be interested to hear if anyone claims there is one. (3) Dire consequences in the Maldives and elsewhere are always being predicted but never seem to happen. (4) There are clearly significant numbers of scientists who don't agree with the consensus. (5) The consensus is not the same as the extreme rises forecast by some people here - who are therefore just as guilty as denialists in ignoring scientific evidence. I've never claimed to be able to take part in a peer review of papers in this subject area. But I do think we can see given such statements as the IPCC Chair's claim about glaciers melting that there is a good degree of misinformation floating about. Bill - What do I make of the chart? Well I said I am not competent to make sense of it, but if it's real sea level as opposed to sea level in relation to land level, then I am frankly puzzled by it, since large parts of the ocean appear to be experiencing a reduction in sea level (quite substantial - 4.5 MM Pa). That makes me think there's something wrong with the measurements, or, alternatively, the measurements as a whole are not indicative of the volume of oceanic water. I presume it is the volume (or even better tonnage AND volume) of oceanic water that we are really interested in, rather than anything else.Moderator Response: [DB] Feed a man a fish and he won't be hungry - for a while. Teach a man to fish and he will never be hungry again. So take the coins of your pocket and invest them in your mind so your mind can then line your pockets with gold. Move beyond the mothers milk to real food. Dikran & Bill have given you all you need to answer your questions for yourself. -
David Horton at 22:16 PM on 14 April 2011Christy Crock #3: Internal Variability
Or, and I realise this is just one of those off-the-planet crazy ideas, we could work out the physics of CO2 in the atmosphere, and then relate the observed temperature changes (and all the associated rapid changes in this little biosphere we call home) to that, see if, by come wild chance, they happen to match. Then we could use computer modelling to work out how that might develop in future, just on the crazy off-chance that the physics and observations and knowledge of past climate shifts are correct. And then, if it looked like the planet was going to be in deep doo doo, what with acidifying oceans, increasing droughts and other severe weather events, rising oceans, melting ice caps, species extinctions, failing agriculture, why, then we could convince the world's governments that there needed to be a quick response in reducing CO2 output. Yeah, that should work I think, not as if there are going to be people trying to stop governments responding to the clear and present danger, are there? -
Gilles at 22:16 PM on 14 April 2011The e-mail 'scandal' travesty in misquoting Trenberth on
well Alec, I think I still can do simple arithmetic computation 1 W/m2 * 4 * Pi*(6,4e6)^2*365*86400 = 1,62 E22 J/yr = 162 E20 J/yr. Now the figures given here are : Land: 2 x 10^20 joules per year Arctic sea Ice: 1 x 10^20 joules per year Ice sheets: 1.4 x 10^20 joules per year Total land ice: between 2 to 3 x 10^20 joules per year Ocean: between 20 to 95 x 10^20 joules per year Sun: 16 x 10^20 joules per year (eg - the sun has been cooling from 2004 to 2008) they're all of the order of magnitude of 10^20, meaning a few % of the last result except for the ocean that can reach almost 10^22. We are speaking of one part of the 0.9W/m2 missing -meaning some 10^21 J/yr missing. This means that oceans represent the main part of heat sinks on the Earth, all the other components being negligible. That's exactly what I meant here, at the very first post of this thread : " the atmosphere stores only a tiny amount of energy" and later here " The sentence should have read: "Our measurements of how much energy goes into the atmosphere, land, and melting ice are accurately known, however."" Oh, yes, sure ! I know it accurately. On average , it's zero." Well zero is a little bit rhetorical - I should have said a few percent of the total. The heat storage takes place essentially in the oceans, all the other components are negligible. Again, what is your point ? -
Dikran Marsupial at 22:14 PM on 14 April 2011Christy Crock #3: Internal Variability
Gilles wrote "I don't think so" Well that settles it then! LOL -
Daniel Bailey at 22:13 PM on 14 April 2011Arctic Ice March 2011
Interesting, logicman, that in the rare event you make an error that you are given correction by one so petardly awash in his own unacknowledged errors. There's a saying in there somewhere about pots and kettles (and another about eyes and planks), but I won't mention it. Look forward to your update! The Yooper -
Dikran Marsupial at 22:08 PM on 14 April 2011Christy Crock #3: Internal Variability
Giles: Now you are just being silly. You can't measure climate variability from one realisation of a stochastic process if the underlying system (e.g. the forcings) is time varying. It simply can't be done without making assumptions about the nature of the noise and of the signal. This is true regardless of how much data you have, or how accurate it is. Secondly, do we have accurate measurements of past climate (beyond a century or so)? No. Are we ever going to get them? No, not unless we discover time travel. The point of paleoclimate studies is to help us understand past climate. The interest is largely in the forcings, not the variability as the variability is essentially paleoweather not paleoclimate. Of course we know that our understanding of the climate is incomplete and the model predictions may not be accurate. It would be idiotic not to realise that, and the climatologists are not idiots. Understanding climate variability does not imply an ability to predict climate variability. I understand the variability of a double pendulum, it is a very simple chaotic system, but that doesn't mean I can't predict it. The whole point of climate projections is to see what is left after excluding the effects of variability. The climate projections shown only the "forced response" of the climate. The spread of the model runs is an indication of what our understanding suggests is plausible given the unpredictable unforced response. The fact you keep harping on about the variability is merely reinforcing the impression that you don't understand how the models work, or what they tell us. Did you read the Easterling and Wehner paper? If not I suggest you do. -
Alec Cowan at 22:07 PM on 14 April 2011The e-mail 'scandal' travesty in misquoting Trenberth on
@Gilles #99 Please, set aside pompous phrases as "as a function on time" and don't distort information. The figure you placed in #99 is clearly identified as OHC700 in Levitus, Antonov, Boyer et al. Maybe if you dig a bit more and actually read the papers and figures you'd be able to find what the 'travesty' is indeed. Maybe when you reach your comment 1000 you'll realize that a) 75% of the oceans are outside what you cited, b) the travesty has to do with that, and c)your intentional double standard is more than obvious. -
Fred Staples at 22:05 PM on 14 April 20112nd law of thermodynamics contradicts greenhouse theory
I agree, Les,977,a vast improvement but a much later, and much up-dated, post than the one I quoted. Though much has gone, much remains from the original – “where does the back-radiation energy go”. It is obvious that there is no second law entropy (quality) problem if we consider only the transfers sun to earth, earth to space, and define the whole solar system as our closed system. Sadly, this ignores completely the transfers we are interested in - earth to atmosphere and back again. The most fundamental point is that you cannot consider the out and back long wave energy transfers in isolation. It is the net transfer (heat transfer) that counts. Petty, page 6, is correct and the version of Trenberth quoted here is grossly misleading. It is not just a matter of using the difference, as someone posted. We can follow G and T, and use heat engines to make the point. It is always possible in principle to convert an energy flow from a warmer source to a colder sink into work (first law). In the process the energy degrades (second law). It is never possible to do the same with an energy flow from a colder sink to a warmer source. If it were possible we would have perpetual motion. It is the net flow that counts (out minus back). The back radiation is the negative term in the Stefan Bolzmann equation. As to the “higher is colder” mechanism, 978,it has nothing to do with back-radiation. Atmospheric emission must balance incoming solar energy, and will be at an appropriate “goldilocks” temperature and elevation to make this happen. If increasing CO2 concentration elevates the emission point (for the sake of the argument) outgoing radiation will be reduced. Incoming radiation will remain the same, so the whole system warms up. The lapse rate moves to the right, and the surface warms. -
Gilles at 22:00 PM on 14 April 2011Christy Crock #3: Internal Variability
"So you got yourself an unfalsifiable hypothesis there Gilles ... useful" Of course it is falsifiable , in the way I said - we COULD find good and accurate proxies of the natural variability and of astronomical changes, TSI, volcanoes, and so on - actually this is the quest of many people in the world. The fact that we don't have them is not due to some "metaphysical" or non scientific character of the question - just to the lack of current good way of measuring it , but it is of course, in principle, measurable. -
Gilles at 21:57 PM on 14 April 2011Christy Crock #3: Internal Variability
"Easterling and Wehner is also a good answer to Gilles canard about the models ability to quantify the variability of the climate." I don't think so.Moderator Response: [DB] Cease with the trolling. -
Gilles at 21:56 PM on 14 April 2011Christy Crock #3: Internal Variability
DM : "That means you can't separate the signal from the noise without making assumptions about both the signal (the forced response) and the noise (the internal variability or unforced response)" I disagree with the assertion that only computer can answer the quesion. In principle, we could, since precise measurements of the variability, and of the natural changes of forcings in the past , could give a good estimate of it. After all, what's the use of paleoclimatic studies and past millenary reconstructions, if not ascertaining the natural variability ? but here we face another problem - the lack of accuracy of these measurements. This is not a *fundamental* problem, it is a *practical* one. If modern thermometers, satellites, and meteorological stations would have existed everywhere in the world for thousands of years, we would probably have much better estimates of the past variability. "the amount of the variability in the model is the amount of plausible variation in climate according to our best understanding of the climate. " Yes, but the "best understanding" can be bad - this has to be kept in mind. There is a number of things in the world we don't clearly understand - and I wouldn't put climate variability in the group of what we DO clearly understand. -
Dikran Marsupial at 21:50 PM on 14 April 2011Monckton Myth #16: Bizarro World Sea Level
Daniel Maris I am going to give you a hand checking up on the WUWT story regarding Morners assertions about sea level rise in the maldives. Please have a look at the following papers (which refute Morners position): John A. Church, Neil J. Whitea and John R. Hunter, "Sea-level rise at tropical Pacific and Indian Ocean islands", Global and Planetary Change, Volume 53, Issue 3, September 2006, Pages 155-168 www, pdf) Philip L. Woodworth, "Have there been large recent sea level changes in the Maldive Islands?", Global and Planetary Change, Volume 49, Issues 1-2, November 2005, Pages 1-18 (www) Colin D. Woodroffe, "Late Quaternary sea-level highstands in the central and eastern Indian Ocean: A review", Global and Planetary Change, Volume 49, Issues 1-2, November 2005, Pages 121-138 (www) but start with Paul S. Kench, Scott L. Nichol and Roger F. McLean, "Comment on 'New perspectives for the future of the Maldives' by Mörner, N.A., et al. [Global Planet. Change 40 (2004), 177–182], Global and Planetary Change, Volume 47, Issue 1, May 2005, Pages 67-69 (www) as this is a peer-reviewed comment on Morners original work on the Maldives (the details of that paper are in the title). Morner's response is here: Nils-Axel Mörner and Michael Tooley, "Reply to the comment of P.S. Kench et al. on 'New perspectives for the future of the Maldives' by N.A. Morner et al. [Global Planet. Change 40 (2004), 177–182]", Global and Planetary Change, Volume 47, Issue 1, May 2005, Pages 70-71 (www). Does the WUWT article mention any of this? If not, why do you think that is? Now I have done enough of your homework for you, it is now up to you to locate those articles (Google Scholar is your friend), read them, and then come back here and either agree that Morner is wrong about the Maldives, or give a cogent scientific defence of his claims. I predict neither of those things will occur - go on, prove me wrong! ;o) -
Alec Cowan at 21:36 PM on 14 April 2011The e-mail 'scandal' travesty in misquoting Trenberth on
@Gilles #97yes multiplying 1 W/m2 by the surface of the Earth and the number of seconds in one year gives something like 10^20 J/year - and so? what does it change ?No, it doesn't. Unless you are considering 1234 x 1020 or 0.00001234 x 1020 to be valid answers, what wouldn't surprise me. But common sense says you didn't bother -or perhaps you couldn't- make a simple calculation. Next time, in order to fool people, say "order of magnitude" instead of "something like". I meant and continue to mean it looks like you don't have any idea about what Trenberth was speaking about in the current topic -that famous email-. Your "dance with numbers" kind of confirm it. The "travesty" comes from a specific 'dialogue' conducted by mail and some contemporary works. -
Dikran Marsupial at 21:17 PM on 14 April 2011Christy Crock #3: Internal Variability
By the way, Christy says "When you look at the possibility of natural unforced variability, you see that can cause excursions that we've seen recently", then if he means the excursions we have seen over the last couple of decades, then he is right and the climate models predict that this sort of thing will happen, see the paper by Easterling and Wehner: David R. Easterling and Michael F. Wehner, "Is the climate warming or cooling?", GEOPHYSICAL RESEARCH LETTERS, VOL. 36, L08706, 3 PP., 2009 (www) This paper shows that the kinds of "excursions" we have seen over the last two decades is expected to happen due to unforced variability (although they can't predict the timing as it is a chaotic weather thing rather than a climate thing), even in the presence of a long term warming trend due to e.g. CO2 radiative forcing. Of course the longer the "excursion" the less plausible the obsertvations become assuming the model assumptions are correct (which is why the models are still falsifiable - the do make falsifiable predictions). Easterling and Wehner is also a good answer to Gilles canard about the models ability to quantify the variability of the climate. -
Dikran Marsupial at 21:06 PM on 14 April 2011Christy Crock #3: Internal Variability
Gilles wrote: "I just reminded that it was very difficult-and almost impossible - to quantify precisely the amount of internal variability by computer models " However, as I pointed out, it is the only way to estimate the internal variability of the climate - you can't measure it directly as we have only one realisation that we can observe. That means you can't separate the signal from the noise without making assumptions about both the signal (the forced response) and the noise (the internal variability or unforced response); as soon as you make a meaningful attempt to do that you end up with somthing very like a climate model. That means you can't argue that the models don't accurately quantify the amount of internal variability as you have no ground truth with which to make such a comparison. Continuing to do so just illustrates your ignorance of the subject. Giles also wrote: "you just get the amount of variability in your model, that's all.". Well duh! Of course, but as the models encode our best understanding of climate physics, the amount of the variability in the model is the amount of plausible variation in climate according to our best understanding of the climate. Given that we can't directy or indirectly measure climate variability (for the reason I have already given), how could climatologists possibly do any better than that. Note the climatologists know this perfectly well, and Gilles could do with resolving his Dunning-Kruger by reading up on climate models and what the modellers claim they can and can't do. -
Eric (skeptic) at 21:02 PM on 14 April 2011Solar Hockey Stick
Dana1981, when you say "If you want to argue that this forcing isn't driving global warming, you need both a low climate sensitivity and a larger "natural" forcing." you are speaking about the long run. Sensitivity is not a constant, it varies as a function of weather. It is likely that sensitivity was higher in the 1990's and enhanced the CO2 warming. It lowered in 2000's to amplify less. No "natural" forcings are needed to attain the variations in warming that we have seen although they are also possible inputs. CBDunkerson, the volcanic response may be short term, but having more frequent volcanoes turns into stratospheric warming over longer periods (e.g. early 20th century). Having less frequent volcanoes (late 20th century with two exceptions) means longer run stratospheric cooling. There is no equilibrium for the stratosphere since it is hit with changing factors from above (solar UV) and below (volcanoes, large scale weather patterns). We are currently in a stratospheric cooling pattern, with some very large magnitudes like NH last winter, due to GHG as a constant over the long term, plus the varying but ongoing short term factors I listed above. -
CBDunkerson at 20:57 PM on 14 April 2011Solar Hockey Stick
shawnhet wrote: "I think that there are plenty of longer term climate changes that do require some unknown mechanisms to explain them." I don't agree... and would have to wonder if you could name any of these "plenty" of long term changes... but it doesn't seem to matter. You've acknowledged (post #47) that most of the recent warming has been caused by greenhouse gas accumulation. At which point all this 'non-linear solar' and 'cosmic ray' stuff comes down to irrelevancy. Maybe they could have some kind of major effect under some kind of wacky circumstances... but they aren't right now (because the most pronounced warming spike of the past few thousand years or more is being driven mostly by GHGs) and there is no reason to think they are going to start doing so. Could some unforeseen climate forcing come along in the future and change everything? Sure. However, until there is actually some evidence of that it doesn't matter. The climate forcings we DO know about are having observed impacts which need to be addressed. -
Lars Rosenberg at 20:49 PM on 14 April 2011Monckton Myth #16: Bizarro World Sea Level
Nils-Axel Mörner's father, Stellan Mörner, was a wellknow swedish surrrealist painter, about whom he has written: "My dad's relation to his art is identical to my relation to my science." That quote may explain some of his inventiveness. -
Gilles at 20:34 PM on 14 April 2011The e-mail 'scandal' travesty in misquoting Trenberth on
100#logicman : AFAICS, the paper deals with uncertainties in the pre-2000 warming, not with the leveling off in the last decade. Of course natural noise can superimpose to long term trend and give for some time an apparent absence of warming - I guess that's what Dr Trenberth is really thinking. But it also means that the same natural noise could also have contributed positively in the past years, and that the "real" trend was after all lower than what we thought. A noise can obviously go in both directions. So in any case, that's an information that models must take into account. -
David Horton at 20:30 PM on 14 April 2011Christy Crock #3: Internal Variability
So you got yourself an unfalsifiable hypothesis there Gilles ... useful. -
Gilles at 20:28 PM on 14 April 2011Arctic Ice March 2011
suggestion , logicman : you weren't wrong because you missed something. You were wrong because your method is wrong - you didn't carefully check for the natural variability before extrapolating what you thought being a "trend" in the evolution of ice pack. Again, any "trend" must be compared with a natural historical variability before being given any significance. First express your observations as a "number of sigmas" above the average level - you may do better predictions. -
Gilles at 20:22 PM on 14 April 2011Christy Crock #3: Internal Variability
enough with strawman arguments, please. I never stated that the influence of forcings was zero. I just reminded that it was very difficult-and almost impossible - to quantify precisely the amount of internal variability by computer models - you just get the amount of variability in your model, that's all. for instance in the "solar hockey stick" post, you find this kind of curvedo you believe we have good models to explain the variation of solar activity over thousands of years ? (again I'm not speaking of the influence on the Earth, just of the origin of solar variations). No - absolutely not - not the slightest idea of where they come from. We have models of the sun - but nothing like explanations of that. So if you rely on models to know if these variations could be "natural" or "anthropogenic", would you conclude that they cannot be natural since the models do not show them, and thus must be anthropogenic ? of course this would be totally absurd. So - we can't rely on models to exclude natural cycles. And yes - natural cycles on timescales of 1000 years can exist, of course. Our modern measurements are much too recent to see them at the required accuracy. Again I am *not* stating that the influence of CO2 is zero. Just that having a very clear separation between it and natural variations is extremely difficult in my opinion, thus reinforcing the uncertainty on the climate sensitivity - and that the outputs of computer simulations are not really useful to fix this issue.
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bill4344 at 19:46 PM on 14 April 2011Monckton Myth #16: Bizarro World Sea Level
D'oh - make that this sort of chart! - http://en.wikipedia.org/wiki/File:NOAA_sea_level_trend_1993_2010.png -
bill4344 at 19:42 PM on 14 April 2011Monckton Myth #16: Bizarro World Sea Level
Gee, that WUWT 'photographic evidence' is, um, compelling. On the strength of those happy-snaps from the Maldives (and 4 - count them, Warmists, 4! - pics of tide gauges) the entire planet can breathe free! I wonder what Daniel Maris would make of his sort of chart?(Speaking of Watts; should we await the Tidal Stations Project with bated breath?)
Moderator Response: [DB] Fixed & hyperlinked chart link. -
Arkadiusz Semczyszak at 19:40 PM on 14 April 2011Christy Crock #2: Jumping to Conclusions?
@Tom Curtis „... dominating influence of the sun ...” I do not say here, the dominant role of the Sun. I (as Christy) say that it is poorly understood and works through delays and too poorly understood feedbacks - it may be estimated wrong: being too big - as you want - but also too small ... The papers, I have cited, say that there is no simple and sufficiently well-known relations - TSI - changes in global temperature. Remember that revealed many solar cycles - can be their superposition. Remember for example the recent (2009) found the cycle c. 6 thousand. years and Holocene optimum. A propos Holocene Optimum - here there were several new papers - worth this topic returning to Sk.S. Steinhilber and Beer, 2011 said several times (outside think cited by MichaelM) that are supporters of the theory of the dominant - currently - the role of A. GHG. But it is precisely because of their sentence, cited by me - has special value. I can cite a similar view of another "hot" supporter of the theory of AGW - Lockwood's,: „... the current grand maximum has already lasted for an unusually long time ...” ... but - the references to these two papers, is not cited by me papers .. -
Bart Verheggen at 19:19 PM on 14 April 2011Christy Crock #3: Internal Variability
A lighthearted take on this issue: Harry Potter lost at sea. If a boat has both an engine running and a sail, it makes no sense to claim that the engine has no effect on the boat's movement. -
Dikran Marsupial at 19:13 PM on 14 April 2011Christy Crock #3: Internal Variability
Gilles Given that the only way to estimate the amount of internal variability is from a climate model (as we have only one realisation of the signal that we have actually observed), it is impossible to say whether the models estimate it "accurately". The error bars on the model projections (which show how much variability is possible) include the observations, which is all that can be expected of the models even if the physics of the model is exactly correct. The climate modellers know this already. Why do you keep on about the models proving anything? They don't and nobody is claiming they do. Models show you the (testable) consequences of a set of assumptions about climate physics. They tell us what we can expect to see based on our best understanding of the climate. Nothing more. As for random initialisations, initialising the initial conditions with the observations for a randomly chosen day would be a random initialisation, and would be a physically realistic initialisation, by definition. As I said, it would be better for you to stop posting on this topic until you have done some background work, you are still just demonstrating your ignorance. -
Gilles at 19:03 PM on 14 April 2011Christy Crock #3: Internal Variability
DM : sorry for repeating : I wasn't wrong, I wasn't speaking of the climate of the Earth but of stellar physics". Replace the sun by a variable star without planets , if you prefer ! I just gave this example of another natural limit cycle which is not due to a variation of forcing. "The whole point of the ensemble is to find out what the climate is doing after internal variability is excluded. " My point is : they're not reliable to estimate the precise amount of internal variability. So they adjust their results to match observations without being certain that the relative proportion of internal variability and sensitivity to forcings is the right one. And the fact that the simulations do not show a long term trend doesn't prove anything. " A large number of model runs are used, all with different random initialisations." There is nothing like "random numbers" in an unrestricted interval. There *must* be a range in which you draw your parameters. Again : how is this range chosen following you ?Moderator Response: [Dikran Marsupial] tags fixed (hopefully the way you wanted them) -
Riccardo at 18:45 PM on 14 April 2011Monckton Myth #16: Bizarro World Sea Level
How can even ultra-skeptics still oppose "photographic evidence" to real science after the debacle of the surfacestation project? -
Dikran Marsupial at 18:40 PM on 14 April 2011Christy Crock #3: Internal Variability
Giles It would be better if you could just admit when you were wrong. The 11 year solar cycle is an external forcing to the models, not part of the models (it has very little effect on the climate anyway). I note you dodge the more substantive issue though, the model projections do not depend on any of the model runs predicting the effects of internal variability accurately. Like other Monte Carlo methods, they don't even attempt to predict internal variability. The whole point of the ensemble is to find out what the climate is doing after internal variability is excluded. If you understood climate modelling, you would know that. Again you last comment demonstrates you don't understand what climate models do. Weather is chaotic, it can't be predicted because we don't have accurate initial conditions (one of the founding fathers of chaos theory, Edward Lorenz, was a meteorologist, chaos theory has its origins in weather modelling, so of course climate modellers are perfectly aware of this). However, just because weather is chaotic, that doesn't mean climate (long term statistical behaviour of the weather) is also chaotic. So rather than predict the chaotic weather, the models simulate weather with the same statistical properties as the real weather and take averages to get information about climate. A large number of model runs are used, all with different random initialisations. After a while, the behaviour of the model is statistically independent of the intialisation (In Monte Carlo simulation, this is called "burn in"). You need initial conditions for weather prediction, which is why weather forecasts are useless beyond five days or so; you don't need them for climate modelling. The reason for choosing 1880 has to do with the availability of reasonably reliable instrumental data (hint, when does GISTEMP start?). I would have thought that was obvious. What is the point of generating hindcasts if you don't have something to use as ground truth? BTW climate models are often used for paleoclimate studies, so it isn't even true that they necessarily start at 1880. I suggest that rather than demonstrate your ignorance of climate modelling and Monte Carlo methods any further, you do some reading and fill in the gaps in your knowledge.Moderator Response: [Dikran Marsupial] This discussion of modelling is heading a bit off-topic. I suggest if you want to discuss what models can and can't do, we continue on climate models are unreliable, although I suggest you read the article and the posts on that thread first. You may also find this post informative, where I use a simpler chaotic system to explain the basic aim of climate modelling and how it works (and why initial conditions are not important). -
Riccardo at 18:36 PM on 14 April 2011The e-mail 'scandal' travesty in misquoting Trenberth on
There are several 6 year periods where the OHC decreased while undoubtely it increased overall. This obvious fact (along with others similar) is the basis of Trenberth question. It's a subtle question though, which apparently many can't grasp. -
Gilles at 18:22 PM on 14 April 2011Christy Crock #3: Internal Variability
DM : "The 11 year solar cycle is *not* reproduced by models either". Well of course it isn't, it is an external forcing!" Unfortunately , you didn't understand my point : I wasn't speaking of the influence of the 11 years cycle on the Earth (it is a forcing for the Earth), I was speaking of physics of the sun, of solar physics - not of climate models. The "forcing" for the Solar activity is merely the internal fusion processes that occur in the core and produce heat that is transferred towards the surface. It doesn't change at all on a 11 years basis (actually it doesn't change on a million years basis , which is the typical escape time for a photon). The input of heat from below is strictly constant - however the output is modulated, not by a change of forcing , but by internal variability which stores part of this energy in magnetic fields and releases it periodically through activity cycles. What I said is that the precise characteristics of this variability (amplitude and frequency) are *not* reproduced by models. This is pretty much the same for "climate" internal cycles like ENSO or multidecadal oscillations. Now concerning the climate models, a simple question : any numerical model requires initial conditions. Obviously the state of the Earth in 1880 isn't very well known. So how is it chosen in simulations ? Note that this problem is somewhat hidden when the results are expressed as "anomalies" - you don't know the absolute value of average temperature. So how are these conditions adjusted, following you ? -
Dikran Marsupial at 18:11 PM on 14 April 2011Monckton Myth #16: Bizarro World Sea Level
Daniel Maris@37 The fact that you have not commented on the Telegraph article that you introduced to the discussion is noted. As I pointed out, that is the behaviour of a denialist, if that is how you want to portray yourself, that is your choice. You also haven't answered the question about whether you have checked the WUWT story out to find out if it is correct or not. Have you checked the photograph depicts what it is claimed to predict? Have you checked the veracity of the tide guages? You do realise that you can't measure global sea level change using a single location, don't you? -
Gilles at 18:11 PM on 14 April 2011How I lived through a carbon tax and survived to tell the tale
"@ Gilles "it wasn't so profitable after all." Yet: Exxon 2008 profit: A record $45 billion" I meant : investing in the exploration of new fields wasn't that profitable after all. Of course high prices increase their income , obviously. The fact is that they made high profits precisely because they didn't all spend this money for finding and starting the exploitation of new fields. That's why a new oil shock is impending - and why production didn't increase that much, despite your economist's forecasts. "It is much the same as the difference between predicting weather and climate." 150$ a barrel was a spike, but prices over 80 $ are definitely a long term trend. Cheap oil is over - and I defy you to find any forecast from your favorite "experts" having predicted this would happen so soon, ten years ago. "That a gradually increasing price on carbon will reduce GHG emissions IS the conventional wisdom of economists. " so why would the production keep on increasing after the exhaustion of conventional resources in BAU scenarios, since non conventional resources require high prices anyway ? You say "because FF companies will earn a lot of money and can turn to more expensive resources", but you didn't explain why the demand would keep increasing! " That is why I have so much confidence that it will work. I like the conventional wisdom of experts." I advised you first to compare their predictions with facts. A french expression says : "An expert is someone who will know tomorrow why what he predicted yesterday didn't happen today". But maybe you say the same in English :) -
Dikran Marsupial at 18:01 PM on 14 April 2011Christy Crock #3: Internal Variability
Giles You have just demonstrated that you don't understand how climate models operate. The projections of the models do not rely on the ability to reproduce internal variability faithfully. The purpose of the ensemble methods (and Monte Carlo simulations generally) is to average out the effects of different realisations of the stochastic effects of internal variability, leaving the signal of interest, which is the forced component of climate change. The real indication that you don't know what you are talking about is the line "The 11 year solar cycle is *not* reproduced by models either". Well of course it isn't, it is an external forcing! Monte Carlo simulation of chaotic physical systems like the atmosphere has a long history, stretching back to the Manhattan project, and have proven very effective in many branches of physics and statistics. As you have not only just demonstrated that you don't understand how the models work, but that you don't even know the difference between internal variability and external forcing, your assertion about whether the models are reliable or meaningful doesn't carry much weight. -
Dan Moutal at 17:43 PM on 14 April 2011How I lived through a carbon tax and survived to tell the tale
@ Gilles "it wasn't so profitable after all." Yet: Exxon 2008 profit: A record $45 billion "it is the conventional wisdom of economists - exactly that that failed to predict oil crisis." Being able to forecast future oil price spikes (aka short term fluctuations) isn't the same thing as predicting what will happen with a gradually increasing price on carbon. Not even in the same ballpark, though it is the same sport (economics). It is much the same as the difference between predicting weather and climate. But you might want to read up on another Canadian Economist (one who does this kind of forecasting) Jeff Rubin. You might surprised at what he predicted. But you are right. That a gradually increasing price on carbon will reduce GHG emissions IS the conventional wisdom of economists. That is why I have so much confidence that it will work. I like the conventional wisdom of experts. Or as some call it consensus (BTW did you look at the document I posted about the consensus of economic opinion?) And finally then we come back to this: "it doesn't address at all the issue of how preventing other people , either elsewhere in the world or in the future , from using the spared FF you let at their disposal." Round and round we go. Back to square one. (Hint: a price on carbon cannot be applied in only one jurisdiction and expected to solve our emissions problem, but we have already been over that before.) I should stop and climb out of this rabbit hole but I have a terminal case of:And I want to see what other gems you might post.
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logicman at 17:13 PM on 14 April 2011The e-mail 'scandal' travesty in misquoting Trenberth on
#99 - Gilles Interesting paper! There are also interesting papers to go with the graph you posted above, at this link: http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/ A legal maxim: evidence should not be taken out of its full context. -
Gilles at 17:05 PM on 14 April 2011Christy Crock #3: Internal Variability
"Leaving all else aside, on the "natural variability" theory, what are the chances/odds that the uptick* in temperatures of the last 3 or 4 decades, say, just happens to coincide, precisely, with the uptick in CO2 production of those same 3 or 4 decades? " David , the answer is : 100 %. Because the CO2 has increased exponentially and thus has always the same characteristic timescale - it has not increased just for 30 years but for hundred years. So *any* multidecadal oscillation will coincide , during its rising part, with a CO2 increase - and with all others anthropogenic variations, such as urban heat for instance; it is a very weak criterion. -
Gilles at 16:58 PM on 14 April 2011Christy Crock #3: Internal Variability
I'd like again stress that it is a generic feature that computer models are generally very bad and unreliable to describe properly internal variability There are numerous examples of that , and very good physical reasons to explain it . Examples include for instance the ENSO oscillation which is not predicted quantitatively by models, and neither all kinds of multidecadal oscillations. The 11 years solar cycle is *not* reproduced by solar models either. The good reason is that these kind of oscillations are not the result of variations of forcings (by definition), but are spontaneous limit -cycles which depend on very sensitive non-linear parameters and cannot be derived from simple conservation laws (that are the only thing giving "robust" results). I give you a comparison : suppose that an extra-terrestrian intelligent being catch a human being and try to "model" it physically. It would be rather easy for him to understand that it is powered by the internal combustion of food and find a rather precise estimate of how much fuel (around 2000 kcal/d) he needs. But it would be very difficult to predict the circadian cycles and why he has spontaneous cycles about 24 hours, just by a physical modeling. So the conclusion is : any argument on unforced variability based on computer simulations is generally speaking unreliable and meaningless. Of course computer models do have their own variability and non linear behaviors, and do exhibit their own internal variability - but it is not justified to use the physical characteristics of this variability as a reliable estimator of the natural ones - no computer model has ever proved to be reliable for that. Of course from time to time, by playing with parameters, you will find similar things - but this is by no ways a robust prediction and cannot be used to predict unknown behaviors. And for instance, we speak of multidecadal oscillations because they have been detected over a century time-scale - but we don't have any precise idea about possible multi-centennal oscillations - that are by no ways excluded by physical arguments. -
Gilles at 16:35 PM on 14 April 2011How I lived through a carbon tax and survived to tell the tale
Dan, your interview doesn't bring anything new , it is the conventional wisdom of economists - exactly that that failed to predict oil crisis. And of course it doesn't address at all the issue of how preventing other people , either elsewhere in the world or in the future , from using the spared FF you let at their disposal. -
Gilles at 16:27 PM on 14 April 2011How I lived through a carbon tax and survived to tell the tale
Applied on oil, the theory fails - I don't know why it would succeed with coal and natural gas, sorry. -
Gilles at 16:26 PM on 14 April 2011How I lived through a carbon tax and survived to tell the tale
I'm sorry gentlemen, but do you have already looked at how much oil do tar sands, CTL, and so on , really produce ? and their contribution to the CO2 increase ? and the planned production for the next 30 years ? before believing all the speeches you hear here and there, first, check the numbers. Marcus : there is a lot of things to answer, but i will only mention one : the fuel cell was * already* invented when the cars appeared, and furthermore first cars were *electric*. All these technologies have had plenty of time to develop and improve - darwinian selection has acted to choose the more efficient. There is absolutely no law saying that things always improve indefinitely - your comparisons are irrelevant. Some things improve more than others, (and then you select them by an a posteriori bias) , but everything we'd like to happen doesn't always happen. Usually , people start realizing that at the age of 10 or so. I know that oil isn't the only FF, but it is the first one to reach its maximal production, so it's a test of the theory "when prices increase, the amount of reserves increases and so the production doesn't decrease" . Applied on oil, the theory fails - I don't know why it would succeed with oil and natural gas. Muoncounter : "By 'the spike,' I take it that you mean 2007-2008. Yet your graph shows that production leveled off in 2005. Unless we have some kind of time-travel inverting causality here, I'm not sure how you accomplish this. " That's a very good point , but may be you could ask another question : but why did prices climb to the sky in 2007 -2008 ? I think your remark gives the answer. This is precisely because the theory fails. The beginning was : first geological constraints limiting the production , then increase of prices. At this point, things derail. Theory says : increase of prices -> more accessible resources -> more production. Why didn't it work? because first increase of oil prices increased also the prices of all commodities , that use oil to be produced , and then extraction costs increased as well ! it wasn't so profitable after all. And then came the recession - no demand anymore. You may think that the recession has nothing to do with oil, I think things are more complicated , but anyway , it gives the answer : demand will not increase because high prices provoke recessions - and if there is no demand, producers won't invest in expensive resources that nobody will buy. -
Bern at 16:05 PM on 14 April 2011Christy Crock #3: Internal Variability
Humanity Rules, have a look at Figure 1 in the article above. Yes, that's right, it's the internal variability as incorporated into the climate models. The "climate science establishment" is well aware of internal variability. They account for it in their models. It doesn't change their conclusions. -
Gilles at 15:51 PM on 14 April 2011The e-mail 'scandal' travesty in misquoting Trenberth on
Ken has a very good idea - if Dr Trenberth could come and make it clearer what he meant, he could also give his opinion about the different posts exchanged here. Concerning what the "lack of warming" could mean , two pieces : the graph of OHC 'Ocean heat content" as a function of timethe leveling off since 2004 and perfectly visible - and continuing. and a paper showing that the oceans may indeed have cooled since this time as in all research papers, the results are certainly disputable, but Dr Trenberth is a real scientist, and facing these facts , he could have only mean what he said : there is a lack of warming, and we have a problem to explain it, because it doesn't match the theory. I don't see why it is complicated, and I wonder why we write pages and pages about it .
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David Horton at 15:33 PM on 14 April 2011Christy Crock #3: Internal Variability
Leaving all else aside, on the "natural variability" theory, what are the chances/odds that the uptick* in temperatures of the last 3 or 4 decades, say, just happens to coincide, precisely, with the uptick in CO2 production of those same 3 or 4 decades? And what are the chances that the combined uptick of the two just happens to coincide with an uptick in denier frenzy on blogs and in the media generally, supported, in large measure, by the corporations responsible for the uptick in CO2 production? *uptick isn't quite right, I seek another metaphor. What is it they play ice hockey with in the northern hemisphere? -
HumanityRules at 15:05 PM on 14 April 2011Christy Crock #3: Internal Variability
I found this quote from Tsonis, it sounds a little more skeptical or at least lukewarmish "a measure of additional ‘background’ warming due to human activity and greenhouse gases that runs across the MDO cycles....I do not believe in catastrophe theories. Man-made warming is balanced by the natural cycles, and I do not trust the computer models which state that if CO2 reaches a particular level then temperatures and sea levels will rise by a given amount." -
logicman at 15:04 PM on 14 April 2011Arctic Ice March 2011
Thanks again for the continued comments. I was wrong. (How many times have you heard a denier say that?) My ice bridge breakup forecast was wrong. Ah well, we learn from our mistakes - hopefully. I hope to publish a new article tomorrow on my blog, giving details of why the ice bridge isn't breaking up as fast as I had expected. Naturally, I shall need to revise my other predictions. I am sorry to be so slow with this. Firstly, I had to investigate to see what factors I had missed. Secondly, I have other articles in my worklist. Thirdly, little things keep getting in the way of my writing: things like life, illness, etc. :) -
HumanityRules at 14:07 PM on 14 April 2011Christy Crock #3: Internal Variability
The point would be that internal variability doesn't have to account for all the recent warming just some of it in some of the recent phases to start to upset the understanding. dana has recently done several post attributing different aspects of 20th century warming to different forcings. I don't remember there being any scope for internal variability to contribute to any of these espisodes of warming or 'cooling' by upto 0.3oC. In fact these would seem like an anathema to both dana and the IPCC's approach which seems to only recognize forcings as drivers of the climate. For example the mid-20th century 'cooling' phase is generally put down to aerosols. This paper suggests natural variability might have played a role in that, that could be as high as 50%. The most recent warming episode (post 1970) might have internal variability contributing 30-40%. Where does the IPCC (or dana) take this into account? The simple fact is if you allow natural variability to add to or subtract from global temperatures then you change the calculations. The convenient just so story has to be rewritten. I don't see that being acknowledged either on this website or within the climate science establishment.
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