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Post by icefisher on Jun 8, 2009 23:50:48 GMT
You haven't shown me a single experiment that demostrates the atmosphere operates as you have described. (A) We have the radiative transfer equations - do you agree? The results of these equations matches emission spectra as observed by satellites - do you agree? (B) The radiative transfer equations calculate transmission at all 'layers' (i.e. at different pressures) of the atmosphere. So we can calculate transmission over, say, a few metres. Therefore we can fill a tube with N2, O2, and 300ppm CO2 and measure IR transmission directly. Then we can do the same with 600 ppm and again measure IR transmission. We can? Where has this been done? How was accuracy determined? Seems you need one without the N2 and O2 as well. Do you agree that if the measurements match the calculations AND the total atmosphere calculations (MODTRAN output) match the observed emission spectra there is a pretty good chance that the RT equations are able to represent IR transmission/absorption throughout the atmosphere. If not -why not? So you are going to just assume back radiation here? I thought that was off topic not to speak of how other processes like evaporation, condensation, convection and conduction are going to affect all this. You seem perfectly satisfied with a far less rigorous standard of experimentation, can you explain why? And how do you deal with the corrolary to all this that a bag of warm non-ghg gases out in space in a bag transparent to IR would never cool. This all began when you maintained that N2 and O2 were as effective absorbers as CO2. I asked you what were the IR absorption bands for N2 and O2. You have not answered this - so I'll ask again. At what wavelengths do these gases absorb. It is important you answer this before we move on. I never said they were as effective as CO2. I asked for evidence of that IR absorption can be measured to a 99.96% accuracy to eliminate the possibility of dilution of the alleged CO2 radiation effect by those other gasses. (e.g. the more the alleged greenhouse effect is provided by relatively IR active benign gases the less warming to attribute to CO2 for a given doubling)
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Post by jimcripwell on Jun 9, 2009 0:25:25 GMT
glc writes "Is there anything about any of these 3 statements with which you disagree? "
Sorry, glc, I do not understand the physics you are talking about to be able to agree or disagree. What I am looking for is references which I can read and study. If you cannot provide the references which I think are absolutely vital, then there is no use in continuing the discussion. Why are the references I am looking for, not essential to understand the IPCC arguments? Do you know of the references or not?
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Post by poitsplace on Jun 9, 2009 7:04:12 GMT
JimC I have put this request before, as you can see by looking at previous posts. Just for starters, I am looking for two references. First a reference that proves that the use of radiative transfer models yields a proper numerical value for the radiative forcing for a doubling of CO2, according to the definition of radiative forcing in IPPC TAR to WG1 Chapter 6. Let's leave the RF definition to one side for the moment and take things one step at a time. I assume you have read the Barrett link which discusses the Schwarzschild Equation given below dI = -Ikr dz + Bkrdz As Barrett writes, this calculates the transmission of radiation of a particular frequency through an absorbing medium. Now then, Jim, do you have a problem with this equation. Is there anything you don't like about it. Is it this for which you need a reference? Second a referene that proves that the only thing that matters in assessing the greenhouse effectiveness of CO2 is the radiation that is emitted at the top of the atmosphere. Ok - do you remember in an earlier post I wrote that, for a roughly stable temperature, we must have Incoming = Outgoing = ~235 w/m2 To which we can add If Incoming > Outgoing the earth warms If Incoming < Outgoing the earth cools Is there anything about any of these 3 statements with which you disagree? I disagree in one important area...it's only half of the physics. Those experiments are for working out absolute absorption. That's great if you're talking purely about an absorption spectrum of some gas cloud back lit by a super-hot (by earth standards) star a thousand light years away. ...but we're NOT talking about a disembodied source of radiation. We're talking about CO2 that is its self a part of the system. CO2 at the same temperature blocks X amount of light based on its concentration...but also EMITS X amount of light based on its spectrum. Sure, half the radiation that CO2 absorbs gets radiated backward...but half of the radiation that CO2 emits on its own (at a loss of thermal energy) gets emitted forward. Do you see the difference? With the bench-top experiment they INTENTIONALLY eliminate CO2's own emissions and have a background source at an intensity far beyond that which would be found HERE. Sure CO2 at room temperature absorbs a lot of energy from a 500C heat source. But the last time I checked the ground wasn't glowing red hot...it's only slightly warmer than the air. The real bottleneck is the coldest region of the atmosphere because the difference in emissions between the ground and the coldest part of the atmosphere is the only difference that you could arguably say is there. Our good friend Socold worked that out to be about 3.39 watts for an increase from 300ppm to 600ppm. Heh...and we've already had a lot of that. However...since the colder part of the atmosphere is sandwiched between two warmer layers, above 80% of the atmosphere and 70C hotter than the ground...I think it's safe to say that the region most likely to warm significantly is the coldest region. Even 1-2C higher temperatures would almost completely offset it's increased absorption from CO2. This is why I've been saying the basic AGW hypothesis only uses HALF of the physics (not unlike the math most use to explain the potential of perpetual motion machines).
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Post by glc on Jun 9, 2009 8:18:09 GMT
We can? Where has this been done? How was accuracy determined? Seems you need one without the N2 and O2 as well.
For crying out loud, I'm simulating the earth's atmosphere and showing that we can use whatever concentrations CO2 we want. It's not a case of "needing" N2 or O2. They are present in the atmosphere. The experiments I describe compare the transmission of IR at 300 ppm and 600 ppm respectively.
Similar experiments to these were conducted by John Tyndall around 150 years ago.
So you are going to just assume back radiation here?.
What?? What do you mean "assume back radiation". At this point all I'm trying to do is to show that we can measure the transmission and absorption of IR radiation through a medium (in this case the atmosphere).
I thought that was off topic not to speak of how other processes like evaporation, condensation, convection and conduction are going to affect all this
Before we go any further. Do you know what I'm talking about when I refer to Absorption, Transmission etc. I've got a strange feeling that you're getting information fom another source without really understanding what you're reading.
I never said they were as effective as CO2. I asked for evidence of that IR absorption can be measured to a 99.96% accuracy to eliminate the possibility of dilution of the alleged CO2 radiation effect by those other gasses.
This is an example of what I mean. I'm guessing the 99.96% accuracy in some way relates to the concentration of CO2 in the atmosphere. To be honest it's difficult to know what you mean.
Let's try this : do you understand what emission spectra graphs tell us?
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Post by glc on Jun 9, 2009 9:40:40 GMT
Sorry, glc, I do not understand the physics you are talking about to be able to agree or disagree. What I am looking for is references which I can read and study. If you cannot provide the references which I think are absolutely vital, then there is no use in continuing the discussion. Why are the references I am looking for, not essential to understand the IPCC arguments? Do you know of the references or not?
Jim (there is an UPDATE to this post below) I wrote down 3 statements i.e
1. Incoming = Outgoing = ~235 w/m2 for a roughly stable temperature 2. If Incoming > Outgoing the earth warms 3. If Incoming < Outgoing the earth cools
Now you tell me that you don't understand the physics. You are right to say that these points are essential to the IPCC arguments but they are essential in a much wider range of atmospheric physics. I am trying to establish what references might be useful to you. If you genuinely don't understand what I mean when I say that "if incoming energy is greater than outgoing energy the earth warms" then you need to start at the very basic level. It would be completely pointless providing references which assume a level of knowledge which you don't possess.
However, I don't believe we need a reference to show that two of my statements (2 and 3) are correct. We can use simple observations. Consider a typical 24 hour period. In the morning the sun rises. As the day progresses it normally gets warmer. Peak warmth normally occurs around 2pm. The reason for the warming is that the earth is receiving more energy from the sun than it is emitting (by radiation, convection, evaporation). In other words
Incoming > Outgoing = Warming (2)
At night the reverse happens. The earth is no longer receiving energy from the sun, but it still can get rid of heat mostly by radiation. As a result the earth cools. The low temperature point is typically around 4am-5am in the morning. This shows that
Incoming < Outgoing = Cooling (3)
Note that ">" and "<" are the symbols for "greater than" and "less than" respectively.
Can I take that you don't need references to 'prove' these basic truths.
UPDATE: I've just realised I included the Schwarzschild equation in the previous post and it might be this that you are unsure about. But again this is not specific to the IPCC and CO2 warming.
Are you familiar with the Beer-Lambert Law? Do you understand Absorption and Transmission? Do you understand what is being measured or calculated? Do you know about the Stefan-Boltzmann equation
The thing is, Jim, I referred you to Jack Barrett's blog where he discusses the radiative transfer equation and explains what the different terms mean. Ok - he might not go into full detail, but there are references to Beer Lambert and the Planck function which you can explore further. I'm afraid there is no easy short cut to understanding "greenhouse theory". You need to be familiar, at least, with the basic physics involved - and I need to know what level of understanding you have before providing any references.
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Post by jimcripwell on Jun 9, 2009 11:10:21 GMT
glc writes ". I am trying to establish what references might be useful to you."
This discussion is going absolutely nowhere. My opinion, for what that is worth, and it probably is not very much, is that the attempt by the IPCC to endrun the problem of being unable to get any experimental data. is that what they produced is all smoke and mirrors. I believe that radiative forcing is a useless concept that can never be given a proper numerical value. I believe that there is not, and never can be, a reference to show that you can get a proper value for radiative forcing as defined by the IPCC. That is the reference I want, and I am certain that not only does it not exist, but that it can never exist. All you are doing is to try and convince me that there is a way to endrun the problem of there being no experimental basis for AGW. Without proper papers published in the scientific literature that I can read and study, you will never accomplish this. I am sure, however, that it does not matter at all whether Jim Cripwell thinks AGW is a hoax.
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Post by glc on Jun 9, 2009 11:56:51 GMT
This discussion is going absolutely nowhere. My opinion, for what that is worth, and it probably is not very much, is that the attempt by the IPCC to endrun the problem of being unable to get any experimental data. is that what they produced is all smoke and mirrors.
Most of the stuff has nothing to do with the IPCC. The basic physics goes back more than 100 years. You're totally cnfused about the role of the IPCC.
I believe that radiative forcing is a useless concept that can never be given a proper numerical value.
I believe there are gaps in your knowledge which need to be addressed and until they are you will continually fail to understand the concepts that are key to AGW theory.
I believe that there is not, and never can be, a reference to show that you can get a proper value for radiative forcing as defined by the IPCC.
Again I suspect you completely misunderstand what the definition says and until you gain a fundamental grasp of the basic physics that situation will continue. I can only repeat the following
There are well established physical laws (which you have been given) which enable us to calculate the absorption/transmission of radiant energy through the atmosphere. This can be done for different concentrations of different gases. From this we calculate how much more absorption/transmission will take place. In other words we can calculate the CHANGE IN FORCING.
That is the reference I want, and I am certain that not only does it not exist, but that it can never exist.
You don't know what you want. If I gave you a reference it is unlikely that you will understand what it is saying. There would be no point in giving you a reference. It will invariably refer to Beer Lambert, Absorption/Transmission, radiative transfer and you have not demonstrated that you have any idea about any of these issues.
All you are doing is to try and convince me that there is a way to endrun the problem of there being no experimental basis for AGW. Without proper papers published in the scientific literature that I can read and study, you will never accomplish this.
But what are you asking? Does CO2 absorb LW radiation? Yes it does Can we calculate the absorption? Yes we can
Read Jack Barrett's blog. He is an expert in Chemistry and Spectrosopy. He has published all the papers you will ever need. The IPCC simply use peer reviewed studies similar to Jack's. Read the blog and then decide what it is you need to know more about. Then contact Jack (or me) and he will provide references for further reading.
Don't keep going on about IPCC references. The IPCC simply gather the 'evidence' from peer reviewed research. There are, therefore, thousands of different references.
In any case I've given you a reference. It's Jack Barrett's blog. Now read it and let me know if there is anything on which you need clarification.
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Post by glc on Jun 9, 2009 12:41:31 GMT
Jim Cripwell
In earlier post I gave this equation
dI = -Ikr dz + Bkrdz
You responded to the post by saying you didn't understand the Physics. Herein lies the problem, Jim . You want a reference which explains how a numerical value is obtained for RF, but you don't understand or want to understand the basic physics that provide that value.
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Post by magellan on Jun 9, 2009 13:15:37 GMT
Jim Cripwell In earlier post I gave this equation dI = -Ikr dz + Bkrdz You responded to the post by saying you didn't understand the Physics. Herein lies the problem, Jim . You want a reference which explains how a numerical value is obtained for RF, but you don't understand or want to understand the basic physics that provide that value. but you don't understand or want to understand the basic physics that provide that value. Stop pretending like you do. Not all scientists agree on the subject, so where does that place you? Reid Bryson says doubling of CO2 in the atmosphere has about the same effect as spitting on the sidewalk. Others say the oceans will boil over, figuratively of course. Does a new thread need to be started asking for evidence?
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Post by jimcripwell on Jun 9, 2009 13:26:10 GMT
glc writes "You responded to the post by saying you didn't understand the Physics. Herein lies the problem, Jim . You want a reference which explains how a numerical value is obtained for RF, but you don't understand or want to understand the basic physics that provide that value."
For the sake of ending this subject, let me agree with you. I am just an ignorant denier who knows nothing about physics, what definitions mean, or anything else.
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Post by icefisher on Jun 9, 2009 13:52:08 GMT
This is an example of what I mean. I'm guessing the 99.96% accuracy in some way relates to the concentration of CO2 in the atmosphere. To be honest it's difficult to know what you mean. Let's try this : do you understand what emission spectra graphs tell us? Yes I understand that is the only experiment you know of is somebody gazing at a spectra analysis having a eureka moment that CO2 has an effect on our atmosphere, at least the top layer anyway, and bought in wholesale hook, line, and sinker into somebody's GCM. Thats coming through loud and clear GLC.
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Post by hiddigeigei on Jun 9, 2009 15:11:27 GMT
The reason for the warming is that the earth is receiving more energy from the sun than it is emitting (by radiation, convection, evaporation). Work?
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Post by glc on Jun 9, 2009 16:04:38 GMT
Stop pretending like you do. Not all scientists agree on the subject, so where does that place you?
There are bits that all agree on. The fundamental physics which results in a forcing change of ~3.7 w/m2 per doubling of CO2 is sound. Reid Bryson says doubling of CO2 in the atmosphere has about the same effect as spitting on the sidewalk. Others say the oceans will boil over, figuratively of course.
You are confusing the radiative forcing with climate sensitivity. some think CS is very low. AGWers think it's ~0.75 deg per w/m2; others reckon it's nearer 0.3 deg per w/m2. Incidentally Wasn't Reid Bryson one of those who was predicting an imminent ice age in the 1970s. He was completely wrong on that and I would suggest he is under-estimating the role of CO2 in the atmosphere.
Does a new thread need to be started asking for evidence?
I've given evidence. I've suggested Jim Cripwell reads the Barrett blog. It might be an idea if you do the same.
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Post by glc on Jun 9, 2009 16:13:44 GMT
Yes I understand that is the only experiment you know of is somebody gazing at a spectra analysis having a eureka moment that CO2 has an effect on our atmosphere, at least the top layer anyway, and bought in wholesale hook, line, and sinker into somebody's GCM.
What do you mean by the following
1. "bought in wholesale hook, line, and sinker into somebody's GCM" 2. "at least the top layer anyway"
Your response suggests to me that you don't actually understand what information is provided by an emission spectrum graph.
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Post by glc on Jun 9, 2009 16:15:54 GMT
For the sake of ending this subject, let me agree with you. I am just an ignorant denier who knows nothing about physics, what definitions mean, or anything else.
Read the Barrett blog (start to finish). Post any questions here.
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