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Post by icefisher on May 29, 2009 1:41:39 GMT
I think you miss the point. In 2005 Hansen wrote: the models do not reproduce reported decadal fluctuationsAnd what is your argument against AGW? That the models do not reproduce a reported decadal fluctuation. The point is there is no need to invoke "missing heat" when OHC has such variation anyway. As long as the longterm trend is upward. What decadal fluctation are you talking about? Decadal fluctations in global temperatures? Where is that in the earth's radiation budget? What could cause it?
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Post by glc on May 29, 2009 10:04:18 GMT
Icefisher This is in response to your low sensitivity statement (i.e. 0.05 for 4xCO2) Magellan posted this Christy link on another thread www.mma-web.org/UserFiles/File/ChristyJR_MS_081002.pdfPlease read Page (Slide) 8, particularly the last 2 points which are Surface temperatures response to 2xCO2 (alone) is ~1 C The associated feedbacks are where the uncertaintities are large (i.e. no confident numbers)
Exactly what I 've been saying consistently throughout the last few months. There is high confidence that increasing levels of CO2 will cause the world to warm. The argument concerns feedbacks. Regarding 'flat', 'non warming' or 'cooling' periods. Think of it like rolling a ball down a steep, rocky hill. We know the ball will eventually reach the bottom of the hill. Basic science tells us this, but we don't necessarily know the exact path it will take. Sometimes it will hit a piece of jagged rock and bounce back up. This hasn't falsified the laws of gravity, though. Similarly, we know that doubling CO2 will increase the earth's temperature by ~1 deg C. However there may well be a few 'rocks' along the way but, just as the ball doesn't falsify gravity, a short-term cooling doesn't falsify AGW. The argument is not, as a number of posters seem to think, about whether CO2 causes warming, it's about how much? If it's just ~1 deg C from pre-industrial levels - No problem. If there are strong positive feedbacks - could be a big problem.
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Post by magellan on May 29, 2009 11:21:30 GMT
glc thinks he's found a new ally
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Post by jimcripwell on May 29, 2009 11:32:13 GMT
glc writes "Similarly, we know that doubling CO2 will increase the earth's temperature by ~1 deg C."
Our discussion got broken off when Kevin cancelled the aphids. How can you be so absolutely certain of this statement? What is your reference(s) for this? Let me point out that there is no experimental data that shows that if you increase the amount of CO2 from current levels, this causes global temperatures to rise. So, am I wrong in presuming that this statement is based on theoretical considerations?
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Post by dopeydog on May 29, 2009 11:47:11 GMT
Actually that degree C for doubling CO2 is pretty credible among a lot of people including many skeptics. It assumes no feedback positive or negative. I've seen an article in wuwt about a month or less on it. I believe Bill Gray agrees with it. Also a big chunk of that doubling has occurred starting from 280 ppm. So we only have about .6 degrees C to go by 2100. Hardly anything that will cause the end of civilization and will probably improve food supplies and the general well being of most on the planet. Correction that might have been the climate skeptic...or both. It is here: www.climate-skeptic.com/2009/04/without-feedback.html
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Post by jimcripwell on May 29, 2009 13:59:35 GMT
dopey dog writes "It is here: www.climate-skeptic.com/2009/04/without-feedback.html " All this says is "The bare value (neglecting rain, effects on other parts of the atmosphere etc.) can be calculated for the CO2 greenhouse effect from well-known laws of physics" No reference to the actual calculations.
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Post by icefisher on May 29, 2009 15:43:47 GMT
Regarding 'flat', 'non warming' or 'cooling' periods. Think of it like rolling a ball down a steep, rocky hill. We know the ball will eventually reach the bottom of the hill. Basic science tells us this, but we don't necessarily know the exact path it will take. Sometimes it will hit a piece of jagged rock and bounce back up. This hasn't falsified the laws of gravity, though. Similarly, we know that doubling CO2 will increase the earth's temperature by ~1 deg C. However there may well be a few 'rocks' along the way but, just as the ball doesn't falsify gravity, a short-term cooling doesn't falsify AGW. What a perfect analogy GLC!!!! Only problem is your description of rolling a ball down a hill is a theoretical one devised in the labratory of your brain. In the real world with a ball, a hill, crevices, trees, rocks, and weeds. . . .seldom does the ball ever get all the way down the hill. Balls rolled down complex geographies seem to more often than not get stuck behind a tree, in a rut, or between a couple of rocks. Thats especially true for balls rolled down gradual hills that take decades or centuries to navigate. You would know that if you actually ever spent time rolling balls down natural terrains. . . .as opposed to the paved playground of your childhood with a pebble or two and your later cerebral physics lab. While thats a perfect example of the problem with theoretical concepts it is incomplete regarding feedback. You did not explain how the ball would go faster down the hill accelerating or from the basic underlying gravitational physics. You see you live in a fantasy world as does all theoretical science until it has been established via observation. And understand what has been falsified is not that GHG can potentially contribute to global warming what has been falsified is that these GHG are going to warm the planet at a certain rate. That is pretty darned dramatic. I will go back to the initial models and the urgency they recommended. That urgency was built on the premise that little time remained. . . .perhaps less than a couple of decades to avoid a tipping point. Well it is now true that tipping point, if it even exists, is far off into the future. One could actually calculate that from the existing models if they were to make the necessary changes to ocean heat content. But no they want to call it "inaccuracies" and not attempt to measure it. They only strive to measure it if its believed to contribute to the theory and in those cases, like man tripling temperature increases from feedbacks like water vapor while ignoring the effects of feedback from evaporation, transport, and condensation to the feedback system. They are on the one leg of that theory like stink on BS. In the current situation in fact it appears the feedbacks are in fact both negative and stronger than CO2 forcing with OHC dropping. Returning to your rolling the ball down the hill analogy. . . .care to explain what could cause the ball to roll back up the hill?
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Post by dopeydog on May 29, 2009 15:54:24 GMT
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Post by jimcripwell on May 29, 2009 15:55:16 GMT
Let me philosophyse on this subject. Many years ago, I and two colleagues did a study. There was a table, and one column had about 10 numbers in it, one of which did not matter. We knew that, as the study was reviewed by our seniors, someone would query the study if one number was missing. So we guessed at the number, knowing the study was still valid if the number was out by a factor of 10. Years later, someone phoned me, and he wanted to use just such a number for real. When I told him the history he was disappointed. Whether he used the number or not, I have no idea. In my career, I have seen a dozen or more instances where meaningless numbers were used in real studies, because people did not go back and check where the original number came from. Many people may know that the Black Death was unlikely to have been caused by the bubonic plague; a more likely explanation is a haemorrhagic virus.
What I am looking for is the "ground zero" report that "proves" that doubling CO2 raises global temperatures by ~1C. Not a reference to a reference, to a reference, etc as can so easily happen. I have searched for such a report, but cannot find it. That does no mean that it does not exist. But there are two possibliities. First it does exist; in which case doubtless glc can give me the reference. Second it does not exist; the implications for this are profound.
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Post by glc on May 29, 2009 17:56:20 GMT
glc writes "Similarly, we know that doubling CO2 will increase the earth's temperature by ~1 deg C."
Our discussion got broken off when Kevin cancelled the aphids. How can you be so absolutely certain of this statement? What is your reference(s) for this? Let me point out that there is no experimental data that shows that if you increase the amount of CO2 from current levels, this causes global temperatures to rise. So, am I wrong in presuming that this statement is based on theoretical considerations?Jim I did respond to this at some length but, as you say, Kevin deleted the thread. I did have a little moan to him, but we have to accept his decisions. Anyway, if I recall, you brought up issues related to convection and evaporation, i.e. mechanisms by which the earth's surface cools other than radiation. You are right about this, but the incoming ~240 w/m2 solar radiation is ultimately emitted by radiation either directly from the surface (via the IR window) or from different layers of the atmosphere. The key is the change at the Top of the Atmosphere. Convection, for example, can carry warm air away from the surface, but cannot emit radiation to space. It is only by radiation that the incoming/outgoing balance is maintained. I know you've also asked about CO2 forcing calculations. I recall Steve McIntyre requesting something similar a few months back. However, for various reasons, I 'm not sure this can be done directly. I'll try and dig something out which gives a better explanation that I'm able to give. Added: This piece by Spencer Weart gives a reasonable summry of the problem: www.realclimate.org/index.php/archives/2008/09/simple-question-simple-answer-no/langswitch_lang/zh
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Post by jimcripwell on May 29, 2009 18:32:33 GMT
glc, you are not addressing my recent query. Our last discussion is relevant, but you state absolutely that a doubling of CO2 causes global temperatures to rise by ~1C. What I am asking for is the "ground zero" peer reviewed scientific paper which presents the calculations, and "proves" that this is correct. You refer me to Real Climate, where I find, at the end of the discussion, "People who refuse to acknowledge that complexity should not be surprised when their demands for an easy calculation go unanswered."
As noted in my latest post, there are two possibilities. Either the reference I am looking for, that "proves" that a doubling of CO2 causes global temperatures to rise by ~1C, exists, or it does not. If it exists, then can you provide this reference, please. If it does not, then, as I noted, the implications are profound.
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Post by glc on May 29, 2009 18:51:23 GMT
What a perfect analogy GLC!!!!
Only problem is your description of rolling a ball down a hill is a theoretical one devised in the labratory of your brain.
Why don't you email Richard Lindzen, Roy Spencer and John Christy and tell them the same thing. You and one or two others are totally out on a limb here. Increasing the concentration of CO2 in the atmosphere will cause the earth to warm. Assuming we continue to emit at the present rate then we can certainly expect global temperatures to be at least 1 deg warmer in 2100 than they were in 1900.
Because of natural variability, this won't necessary be a straightforward linear rise. Volcanos, ocean oscillations and other factors will mean that there will be periods of 'non warming'. Now, if you have some scientifically justified argument of why the expected warming won't happen then, by all means let's hear it. However, you appear to be saying that something unspecific may happen which will stop the warming (a bit like a ball getting stuck in a crevice). However remote, that is a possibility. But using the same logic we must also consider the possibility that the warming will increase at a much faster rate and the rise in temperatures will be much higher than we previously thought.
With current scientific knowledge, feedbacks appear to be the variable factor. Richard Lindzen maintains that feedbacks are negative, though he did use incorrect data to demonstrate this. Roy Spencer suggests no feedback. Pro-AGW scientists insist there is a strong feeback factor which will lead to ~3 deg warming. Me - I go for low/no feedback. I think that the post-1975 warming has been amplified by natural factors just as the 1910-45 warming was, and that the underlying trend is ~0.05 deg per decade which will eventually lead to a total warming of ~1.2 deg. Exactly the amount basic theory predicts.
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Post by jimcripwell on May 29, 2009 19:52:04 GMT
glc writes " Increasing the concentration of CO2 in the atmosphere will cause the earth to warm."
Here we go agian. Reference please.
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Post by icefisher on May 29, 2009 20:07:00 GMT
What a perfect analogy GLC!!!!
Only problem is your description of rolling a ball down a hill is a theoretical one devised in the labratory of your brain.Why don't you email Richard Lindzen, Roy Spencer and John Christy and tell them the same thing. You and one or two others are totally out on a limb here. Increasing the concentration of CO2 in the atmosphere will cause the earth to warm. Assuming we continue to emit at the present rate then we can certainly expect global temperatures to be at least 1 deg warmer in 2100 than they were in 1900. Thats an unimpressive argument GLC. Opinions are a dime a dozen. Lets face it most people relish taking a position on matters indeterminate. Las Vegas would not exist but for that penchant. Its probably an even bet you can get all those guys to predict what color the roulette wheel will land on, as long as the personal stakes are trivial. Some professions though have standards about what opinions should comprise and a minimal standard for the amount of evidence to support the opinion. The personal stakes are your livelihood and even your entire personal wealth. It would be interesting to hear what opinions may be held under those circumstances. Because of natural variability, this won't necessary be a straightforward linear rise. Volcanos, ocean oscillations and other factors will mean that there will be periods of 'non warming'. Volcanos can certainly affect this as it affects incoming radiation but how do oceans do it? Now, if you have some scientifically justified argument of why the expected warming won't happen then, by all means let's hear it. I do look forward to you producing those forcing calculations. However, you appear to be saying that something unspecific may happen which will stop the warming (a bit like a ball getting stuck in a crevice). However remote, that is a possibility. But using the same logic we must also consider the possibility that the warming will increase at a much faster rate and the rise in temperatures will be much higher than we previously thought. Possibilities are endless. We could get hit by an asteroid next year. Perhaps you could also provide calculations and necessary supporting evidence of why such feedbacks are "probable" if you believe them to be so. With current scientific knowledge, feedbacks appear to be the variable factor. Richard Lindzen maintains that feedbacks are negative, though he did use incorrect data to demonstrate this. Roy Spencer suggests no feedback. Pro-AGW scientists insist there is a strong feeback factor which will lead to ~3 deg warming. Me - I go for low/no feedback. I think that the post-1975 warming has been amplified by natural factors just as the 1910-45 warming was, and that the underlying trend is ~0.05 deg per decade which will eventually lead to a total warming of ~1.2 deg. Exactly the amount basic theory predicts. There you go. 4 separate opinions all different. In a world where you are held accountable for your opinions you never see anything like that among professionals. Not that everything is cut and dried, but there is a middle ground of disclaimers, complete disclosure of uncertainties. . . .you know all the stuff that folks like Schneider and Mann say would be destructive to their cause. In the financial world such clarity and caution goes beyond advisory into the realm of compulsory. These people operating under a CPA banner would be criminals subject to imprisonment. In other words such stuff doesn't rise to adequate as a "professional opinion" for somebody investing in today's financial world. Considering the ramifications of this issue standards should be surrounding it also.
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Post by glc on May 30, 2009 9:51:54 GMT
There you go. 4 separate opinions all different.There aren't 4 separate opinions - there are 2, i.e. Low feedback v High feedback. You are trying to suggest there is wild disagreement where there isn't. Despite attempts by amatuer bloggers to fudge the issue, there is a clear recognition among scientists (sceptic and pro-AGW) that increasing CO2 will result in a warmer world. How much warmer depends on feedbacks. The question is not whether the presence CO2 causes warming. That's been answered - It does. Jim Cripwell (and Icefisher) Re: forcing calculations Why don't you see if it's possible to download the Modtran source code. The calculations will show up in there. It' s worth reading this link www.barrettbellamyclimate.com/page24.htmNote the increase from 300ppm -> 600ppm results in a change in temperature from ~287K -> 288K. In the link JB writes One method of estimating the contribution made by the presence of CO2 to the total 34·5°C of global warming is by the use of the MODTRAN programme and database, which contains all the spectral information about greenhouse gases and allows the calculation of fluxes at any altitude, looking downwards to the surface or upwards towards space.Jim You must be aware that it's not possible to simply write down caclulations on a side of A4 to solve most real life problems. If we could solve everything analytically with a bit of calculus, then 80% of the world's physicists and mathematicians would be out of work. However, there are some simple Energy Balance Models which are relatively easy to understand and which give a reasonable approximation to the true forcing. If I remember where I've seen them I'll post the links.
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