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Post by steve on Apr 29, 2009 14:29:11 GMT
Jim, I need to understand what aspects you are unhappy with. Could you accept that it is possible to predict the radiation emitted by a blob of gas of known constituents and known temperature? Could you accept that it is possible to reasonably accurately predict the amount of radiation of different wavelengths absorbed by a blob of gas of known constituents and known temperature? What do you understand by the term "radiative forcing"? Hi Steve. Jim has been unbelievably patient with you -- saintlike! For you to condescend further ("What do you understand by the term radiative forcing?" is not going to help you win anyone over to your side. I'm not being condescending at all, or try to "win" anyone over. I don't understand Jim's issues. The words Jim uses to answer the questions will help me understand where he is coming from. Part of my job is technical user support, and going back to "first principles" is often a good way of getting to grips with a user's issue. Sometimes the user has made a mistake. Sometimes it is something ambiguous in the system or system documentation.
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Post by jimcripwell on Apr 29, 2009 15:15:58 GMT
steve I dont know how to be clearer. Radiative transfer models exist to solve problems where it is correct to assume that the only way energy is transferred through the atmosphere is by radiation. At least that is my understanding. If this is wrong, please tell me what radiation transfer models are used for. Assuming I am correct, radiation transfer models were not developed to estimate the radiative forcing of CO2. Maybe they are useful for estimating the radiative forcing of CO2. Maybe they are not. I dont know. But it seems to me that there is an onus of Myhre el al to show conclusively that radiative transfer models are, indeed, suitable to estimate radiative forcing. Maybe they have done so, but if they have, I cannot find the reference. Where is the reference that shows that Myhre et al have shown conclusively that radiative transfer models are suitable to estimate the value of radiative forcings?
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Post by socold on Apr 29, 2009 15:33:06 GMT
Footnote from that web page: " Note: this Website does not cover developments from the 1980s forward in radiation models (nor the technical details of the other components of general circulation models, increasingly numerous and sophisticated )." Doesn't need to, the physics supported warming from rising co2 long before the 80s. As the site explains.
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Post by socold on Apr 29, 2009 15:36:49 GMT
socold: your link is a gushing, over-the-top lionization of computer modelers that could have been written by Pravda. Nonetheless, it does include an important paragraph: If it was over-the-top you wouldn't be able to find a "nonetheless important paragraph" in there. Maybe it only sounds that way because all you have read are ignorant gushings about models from skeptic blogs, which tend to for all practical purposes just dismiss them out of hand. Climate science being in it's infancy doesn't mean the evidence aint strong that rising co2 causes warming.
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Post by socold on Apr 29, 2009 16:48:17 GMT
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Post by steve on Apr 29, 2009 17:42:20 GMT
steve I dont know how to be clearer. Radiative transfer models exist to solve problems where it is correct to assume that the only way energy is transferred through the atmosphere is by radiation. At least that is my understanding. If this is wrong, please tell me what radiation transfer models are used for. Assuming I am correct, radiation transfer models were not developed to estimate the radiative forcing of CO2. Maybe they are useful for estimating the radiative forcing of CO2. Maybe they are not. I dont know. But it seems to me that there is an onus of Myhre el al to show conclusively that radiative transfer models are, indeed, suitable to estimate radiative forcing. Maybe they have done so, but if they have, I cannot find the reference. Where is the reference that shows that Myhre et al have shown conclusively that radiative transfer models are suitable to estimate the value of radiative forcings? Where I disagree is where you think radiative transfer models are not useful because radiation is not the only way in which energy is moved around the system. Radiative transfer models are part of a model system. Their role is to model that bit of the system relating to radiative transfer. They are coupled with other model components that relate to convection, etc. The convection model will also "move" energy around the system in the form of warm air. Precipitation and surface exchange schemes deal with evaporation, transpiration etc. that are also movements of energy. Since the earth loses virtually all its energy through radiation, then the radiative transfer model, with a correct atmosphere profile, should be able to calculate the amount of radiation being lost at a given moment in time. If you increase the amount of CO2, then it interferes with the radiative transfer by reducing outgoing longwave radiation. The amount of "radiative forcing" is the amount of reduction in outgoing longwave radiation assuming that the atmosphere's profile doesn't change. Myrhe is focused on ensuring that this calculation is done correctly. The earth will of course adjust as a result of the addition of the CO2, and the adjustment will affect the behaviour of all components in the coupled model including the radiation model. But to adjust to the radiative forcing, the earth has to increase the amount the it radiates to overcome the extra CO2, or reduce the amount of solar energy it absorbs. That's the "basic physics" bit. The complicated bit is working out how the earth adjusts.
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Post by jimcripwell on Apr 29, 2009 18:24:57 GMT
steve writes "Myrhe is focused on ensuring that this calculation is done correctly."
Maybe we are zeroing in on the problem. Where does Myhre prove that the calculation is done correctly?
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Post by nautonnier on Apr 29, 2009 23:07:29 GMT
And how much water vapor was in those 'clear sky columns'? I don't suppose that the metrics were normalized for it. This is rarely done - for example the reports on contrails over Reading (40 miles west of London) totally failed to normalize for water vapor; and the 'days after 9/11' report from NASA about how cold it was without aircraft - also failed to report that there was a huge dome of high pressure and very dry air over the entire Eastern seaboard and into the mid-west - unsurprising that it was cooler. The 911 example is daft, as noone seriously trusted the claimed link. The IPCC report looked quite hard at contrails purely on the basis of one report and they concluded that there wasn't much effect from contrails (didn't the report say it was warmer post 9/11? - I can't remember - I know I nearly got lost in fog in the Rockies). " The 911 example is daft"I agree that the idea is daft but it was rolled out (and is often reshown) as a documentary showing the NASA people from Langley stating how the lack of aircraft *caused* the drop in temperatures. (Indeed the link to the documentary was posted on here around 6 months ago). I have not seen their paper withdrawn. The research paper on contrails was not issued by IPCC but was published by the Reading based Meteorological Research Centre. It was reported as a peer reviewed paper (letters) in (I believe) Nature. The point I am belabouring making is that there is a continual blind spot about normalizing metrics for water vapor as it is assumed not to be a forcing. As is shown by the IPCC AR4 diagram that is repeatedly shown here. The only time that water vapor appears to be considered by the AGW proponents is when it is quoted as a positive feedback to CO 2 forcing.
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Post by magellan on Apr 30, 2009 1:45:46 GMT
steve writes "Myrhe is focused on ensuring that this calculation is done correctly." Maybe we are zeroing in on the problem. Where does Myhre prove that the calculation is done correctly? Where does Myhre prove that the calculation is done correctly?jimcripwell gets the prize ;D Now steve, please tell us where Miskolczi's calculations are incorrect. I encourage everyone watch the following and understand just what Miskolczi is saying. www.youtube.com/watch?v=Ykgg9m-7FK4
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Post by FineWino on Apr 30, 2009 3:04:04 GMT
Socold, if the physics of the models is over your head, but you believe in the output of the models, then what you have is "Faith", not "Understanding" or "Knowledge." Since you do not understand the physics, please refrain from using references that you do not understand as part of your argument. It would appear that like most warmers, you are a zealot who has no understanding of the actual science (or lack thereof) but has a need to believe in the concept of AGW. It is impossible to meet magellan's challenge. Models are not science, models are just a non interactive video (or or non-video) game. They are full of approximations, parameters, and, quite frankly, guesses. Occasionally, a model comes close to duplicating the actual behavior of a system. That has not yet happened with a climate model. The concept of AGW is B.S., but the mandate of the IPCC specifically charges them "...to assess on a comprehensive, objective, open and transparent basis the latest scientific, technical and socio-economic literature produced worldwide relevant to the understanding of the risk of human-induced climate change, its observed and projected impacts and options for adaptation and mitigation." That is a direct quote from the IPCC site. Without "human-induced climate change", there is no need for the IPCC. So here we are....
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Post by steve on Apr 30, 2009 9:37:30 GMT
steve writes "Myrhe is focused on ensuring that this calculation is done correctly." Maybe we are zeroing in on the problem. Where does Myhre prove that the calculation is done correctly? As with all science papers, references to previous work are given which support the basis of the work. Typically, they will also refer to previous work that the new work either differs with or agrees with. In this case, the radiation models being used are referenced. You can check the references. Above I linked to the documentation and code for a later version of one of these radiation models. Additionally, the Myhre paper is using 3 different methods which give similar results. That in itself adds to the justification of the paper unless you can show a reason why all the methods give similar results. I think it is valid that full earth system models give similar results because they are based on similar data. I don't think it is likely true for radiation models because they have wider applications and because the fundamental problem is much simpler.
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Post by steve on Apr 30, 2009 9:49:56 GMT
The 911 example is daft, as noone seriously trusted the claimed link. The IPCC report looked quite hard at contrails purely on the basis of one report and they concluded that there wasn't much effect from contrails (didn't the report say it was warmer post 9/11? - I can't remember - I know I nearly got lost in fog in the Rockies). " The 911 example is daft"I agree that the idea is daft but it was rolled out (and is often reshown) as a documentary showing the NASA people from Langley stating how the lack of aircraft *caused* the drop in temperatures. (Indeed the link to the documentary was posted on here around 6 months ago). I have not seen their paper withdrawn. The research paper on contrails was not issued by IPCC but was published by the Reading based Meteorological Research Centre. It was reported as a peer reviewed paper (letters) in (I believe) Nature. The point I am belabouring making is that there is a continual blind spot about normalizing metrics for water vapor as it is assumed not to be a forcing. As is shown by the IPCC AR4 diagram that is repeatedly shown here. The only time that water vapor appears to be considered by the AGW proponents is when it is quoted as a positive feedback to CO 2 forcing. Papers are rarely withdrawn. The problem seems to be that the conclusion is not supported by other findings and has better explanations. Sorry about my vague reference to the IPCC - I meant that I recall reading in the IPCC the review of contrails work. Water vapour as a forcing is considered in the IPCC report. In particular see Section 2.3.7 which discusses stratospheric water vapour - some of which is "anthropogenic", and Section 2.5.6 which discusses water vapour from irrigation and land use changes. There is no blind spot here.
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Post by icefisher on Apr 30, 2009 11:13:06 GMT
Models are not science, models are just a non interactive video (or or non-video) game. They are full of approximations, parameters, and, quite frankly, guesses. Occasionally, a model comes close to duplicating the actual behavior of a system. That has not yet happened with a climate model. I think the best description of a scientific model is the film "The Fly".
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Post by socold on Apr 30, 2009 11:38:58 GMT
Socold, if the physics of the models is over your head, but you believe in the output of the models, then what you have is "Faith", not "Understanding" or "Knowledge." It's called deference. Everyone does it. I am also not an expert in quantum physics or an expert in biological evolution to understand the details and math, but I don't need faith to believe in either theories. I can reasonably defer to the experts on the details and instead focus on the higher level picture. This entire thread is skeptics asking for evidence that they wouldn't understand anyway. Perhaps you need to level your complaint at the original perps. Yes but not in the way you suppose. wrong, it's a skeptic crock that models are highly inaccurate - they actually repdroduce a hell of a lot of our climate. www.metoffice.gov.uk/corporate/pressoffice/myths/6.htmlIt's easy for skeptics to just say things like "computer games" and "models are not reality" and other buzzphrases like that. Fine, they are just glossing over something they don't understand. So it's ironic for you to tell me I can't accept models because I don't understand the detailed underlying physics. Do the skeptics understand it to dismiss them?
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Post by jimcripwell on Apr 30, 2009 13:21:59 GMT
steve. Let me put our discussion into a wider historical perspective. I am, to some extent, speculating what happened. When the IPCC was formed, it was given a mandate to scientificly prove that CO2 was evil. They were faced with an insuperable problem, that they could never get any experimental data, because you cannot do experiments on the earth's atmosphere. They hunted around the literature, and found the concept of radiative forcing (RF) which was thought up over 100 years ago. The people who thought up RF almost immediatley abandoned the concept for two reasons. First it can never be measured, and second any numerical value can only be arrived at by so oversimplifying how the atmosphere works, that any numbers are completley meaningless. The IPCC could not, of course, do anything about experiements, but with the advent of high speed digital computers they could give the appearance that they had modelled the stmosphere well enough that numerical values of RF had a meaning. This is where Myhre came in. He found the radiative transfer models, and realized that he could pretend that they gave a proper value for RF. There were, at the time, no climate skeptics so the 1998 paper got into the literature. It has been quoted and requoted so many times that the numbers now appear to be written on tablets of stone. But any proper examination of the 1998 paper shows that it is basically scientific garbage. What I am trying to do is to turn a lot of scientific searchlights onto Myhre et al 1998 to show just how bad it is. Finally, after many years, people with appointments before their name, and initials after their name are starting to state the obvious in connection with AGW. On CCNet today we have two lovely quotes "science has evolved to the dangerous point where model-building has precedence over observation and measurement," and "One of the most important challenges of our time is modeling global climate."
Important scientists are starting to state the obvious; that the numbers that come out of models cannot be a substitute for experimental data. It never will be possible to get a proper scientific value for the RF of the doubling of CO2. The warmaholics have done a magnificant job of persuading a gullible public that they have done so, but they are wrong. And there is nothing you can say that will persuade me otherwise. Myhre et al 1998 is simply smoke and kirrors, and scientific garbage.
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