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Post by steve on Jun 10, 2009 20:41:21 GMT
So if a given layer (within which no condensation or evaporation takes place) receives, say 130 units of energy from below, 70 units from above, it will reemit 200 units - half of them up and half of them downwards. That is illogical. If a molecule gains energy from IR some of that energy will be manifested as heat which will find other escape route. According to your model the atmosphere never heats up. You need to learn the meaning of "if". It's an illustration. And? How many frying pans are in the atmosphere?
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Post by poitsplace on Jun 10, 2009 20:53:07 GMT
I would have thought the highest area of absorption for co2 would be the warmer parts near the surface because there you have a higher amount of co2 per volume of atmosphere. It's true it does absorb more...but having the same temperature as the ground means they emit just as much of their own energy from thermal excitation as the ground (within their spectrum at least). Sure they emit "back radiation" but they also emit FORWARD radiation. Even the unsaturated bands do that. They let through some but they also emit some. Didn't it ever seem odd to you that by the math used for AGW...TECHNICALLY CO2 could never lose any of its heat on its own? That's why I've been saying the absorption figures for AGW only used HALF of the math. They ignored that CO2 emits.
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Post by steve on Jun 10, 2009 20:53:15 GMT
I would have thought the highest area of absorption for co2 would be the warmer parts near the surface because there you have a higher amount of co2 per volume of atmosphere. As socold says, yes. The amount of absorption by co2 or any other greenhouse gas is pretty much dependent on the amount of that greenhouse gas, and less dependent on the temperature of the gas. We have the structure of the atmosphere that we have because of all the contributions of radiation, convection, latent heat of phase change of water, thermodynamics, atmospheric dynamics and, yes icefisher, even conduction. The reason why the cold parts of the atmosphere are cold is because that is the temperature that results from the current balance of energy in and energy out. These cold areas maybe do not absorb more radiation simply because there isn't the radiation to absorb (because the layers near them are *also* cold, and therefore not radiating much).
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Post by steve on Jun 10, 2009 21:19:43 GMT
I would have thought the highest area of absorption for co2 would be the warmer parts near the surface because there you have a higher amount of co2 per volume of atmosphere. It's true it does absorb more...but having the same temperature as the ground means they emit just as much of their own energy from thermal excitation as the ground (within their spectrum at least). Sure they emit "back radiation" but they also emit FORWARD radiation. Even the unsaturated bands do that. They let through some but they also emit some. Didn't it ever seem odd to you that by the math used for AGW...TECHNICALLY CO2 could never lose any of its heat on its own? That's why I've been saying the absorption figures for AGW only used HALF of the math. They ignored that CO2 emits. You're losing me now. Back radiation is emission from CO2 and other greenhouse gases towards the ground. Clearly there will be "forward radiation", though I don't think anyone calls it that. Your basic radiation model will model a large number of layers of the atmosphere. In each iteration of the model the emission of each layer will be calculated based on its temperature and constituents; the amount of this emission that is absorbed by each of the other layers will be calculated based on the emission spectrum and the constituents of each of the other layers. (In between each iteration, the other processes in the atmosphere are modelled such as convection etc.). In saying this, I'm not going to get into another battle about whether the model is any good. But it is not true to claim that obvious things are missing from the understanding of the radiative impact of increasing greenhouse gases.
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Post by poitsplace on Jun 11, 2009 4:12:39 GMT
You're losing me now. Back radiation is emission from CO2 and other greenhouse gases towards the ground. Clearly there will be "forward radiation", though I don't think anyone calls it that. See this is where most people have lost it. For a given temperature CO2 emits its own spectrum at levels. If there's a black body source behind the CO2 and the CO2 is at the same temperature...no spectrum will be observed. The so-called "back radiation" from the black body source is compensated for by the fact that the CO2 emits just as much energy due to thermal excitation. Basically if they're at the same temperature...concentration of CO2 does nothing. Since they use the absolute absorptive capability of CO2 from the start...it's missing. You can tell its missing because their forcing numbers are too high. Even if NONE of CO2's frequencies had made it up to the coldest part of the atmosphere...that part of the atmosphere would STILL emit at levels based on its concentration of CO2 and temperature.
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Post by steve on Jun 11, 2009 18:30:39 GMT
You're losing me now. Back radiation is emission from CO2 and other greenhouse gases towards the ground. Clearly there will be "forward radiation", though I don't think anyone calls it that. See this is where most people have lost it. For a given temperature CO2 emits its own spectrum at levels. If there's a black body source behind the CO2 and the CO2 is at the same temperature...no spectrum will be observed. The so-called "back radiation" from the black body source is compensated for by the fact that the CO2 emits just as much energy due to thermal excitation. Basically if they're at the same temperature...concentration of CO2 does nothing. Since they use the absolute absorptive capability of CO2 from the start...it's missing. You can tell its missing because their forcing numbers are too high. Even if NONE of CO2's frequencies had made it up to the coldest part of the atmosphere...that part of the atmosphere would STILL emit at levels based on its concentration of CO2 and temperature. But by adding a bit more CO2, the proportion of emitted energy that goes into space from a given layer (so cooling the earth) reduces. The difference needs to be made up by more emission. More emission can be due to increased emissivity or increased temperature. I'm saying that increased temperature is required.
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Post by icefisher on Jun 11, 2009 19:36:50 GMT
But by adding a bit more CO2, the proportion of emitted energy that goes into space from a given layer (so cooling the earth) reduces. The difference needs to be made up by more emission. More emission can be due to increased emissivity or increased temperature. I'm saying that increased temperature is required. Thats true even if you add more non-ghg to the atmosphere by increasing the average height at which emissions are emitted. The only thing that matters is how much does it raise the temperature and nobody obviously knows how to figure that out.
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Post by glc on Jun 11, 2009 20:14:14 GMT
Thats true even if you add more non-ghg to the atmosphere by increasing the average height at which emissions are emitted. The only thing that matters is how much does it raise the temperature and nobody obviously knows how to figure that out.I don't know why you keep saying this. (1) It's not true that the same will happen if non-ghgs are added and (2) The change in forcing can be calculated by using radiative transfer equations. I recall Steve McIntyre looking into the CO2 forcing issue about 18 months ago. His comclusion about the importance of CO2 is as follows (See www.climateaudit.org/?p=2572 ): "The large notch or "funnel" in the spectrum is due to "high cold" emissions from tropopause CO2 in the main CO2 band. CO2 emissions (from the perspective of someone in space) are the coldest. (Sometimes you hear people say that there's just a "little bit" of CO2 and therefore it can't make any difference: but, obviously, there's enough CO2 for it to be very prominent in these highly relevant spectra, so this particular argument is a total non-starter as far as I'm concerned. )" This is exactly the argument I've been making but which you have failed to grasp. The CO2 absorption signal is absolutely clear.
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Post by icefisher on Jun 11, 2009 20:22:07 GMT
Thats true even if you add more non-ghg to the atmosphere by increasing the average height at which emissions are emitted. The only thing that matters is how much does it raise the temperature and nobody obviously knows how to figure that out.I don't know why you keep saying thus. The change in forcing can be calculated by using radiative transfer equations, We aren't talking about pure batches of CO2 GLC, nor for that matter are we talking about forcings.
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Post by glc on Jun 11, 2009 20:33:49 GMT
We aren't talking about pure batches of CO2 GLC, nor for that matter are we talking about forcings.
What do you mean by "pure batches of CO2". Forcings lead to temperature change. Read my earlier post again it's been updated (see Steve McIntyre comment)
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Post by socold on Jun 11, 2009 20:37:25 GMT
You're losing me now. Back radiation is emission from CO2 and other greenhouse gases towards the ground. Clearly there will be "forward radiation", though I don't think anyone calls it that. See this is where most people have lost it. For a given temperature CO2 emits its own spectrum at levels. If there's a black body source behind the CO2 and the CO2 is at the same temperature...no spectrum will be observed. Too right we've lost it, that paragraph doesn't make any sense whatsoever. No spectrum will be observed? What on earth is that supposed to mean. Rather than thinking you have found some simple flaw in physics which physicists for decades have missed, you would be better off trying to understand what these words mean. It makes no sense to say "no spectrum will be observed".
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Post by icefisher on Jun 11, 2009 21:49:55 GMT
We aren't talking about pure batches of CO2 GLC, nor for that matter are we talking about forcings.What do you mean by "pure batches of CO2". Forcings lead to temperature change. Read my earlier post again it's been updated (see Steve McIntyre comment) Nobody here is suggesting CO2 has no effect. As you well know there is an extinction curve for the effect of CO2. Additionally the estimate of the contribution of current CO2 to planet warming has a wide range of possibilities. I have heard from 9 to 30%. Your radiative equations need to deal with all these factors. You are running around with a favored calculation and completely unable to produce a single shred of evidence or study that favors your number. Yes indeedy, more CO2 makes for more warming; but I haven't seen anything to convince me of how much. As I see it what we have is some science based upon pure batches of CO2, spectra etc. We have some space spectra that shows those areas largely eliminated from the cooling profile of the earth and hardly anything in between regarding the actual route the heat is taking to space. The sycophants of the AGW movement like to point to recent warming and run some calcs on that and come up with forcings and theories about how the results were obtained in the real world. Problem with those theories is they operate from the assumption of very little natural variation, which has already been proven false. So you are running around with some falsified forcings and other theories like they are the holy grail or something. I agree add any gas to the atmosphere and you will warm the planet. Add CO2 gas and you will warm it a little more probably depending upon the physics of how the IR is getting around the CO2. Very clearly though the IR is getting around the CO2 in more ways than via simply warming the surface of the planet and emitting more IR. That is only one of the ways its doing it.
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Post by poitsplace on Jun 12, 2009 4:27:59 GMT
Rather than thinking you have found some simple flaw in physics which physicists for decades have missed, you would be better off trying to understand what these words mean. It makes no sense to say "no spectrum will be observed". I didn't say it was a flaw in physics. I said it was ignored by AGW math. And also pointed out that if the whole system were at the same temperature the absorption spectrum of CO2 would be canceled out by the emission spectrum.
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Post by captainhigley on Jun 12, 2009 5:06:24 GMT
icefisher said: The sycophants of the AGW movement like to point to recent warming and run some calcs on that and come up with forcings and theories about how the results were obtained in the real world. Problem with those theories is they operate from the assumption of very little natural variation, which has already been proven false.
All of this detailed discussion of CO2 warming effects is a nice exercise, but the warming that is predicted in the upper atmosphere has completely failed to occur. The concept that a trace gas would drive the climate to any measurable degree borders on laughable.
If you use the real thermodynamic alpha for CO2 and not the falsified, augmented value the IPCC created, we are talking thousandths or at most a hundredth of a degree warming with doubling of CO2. Furthermore, water vapor is a negative forcing factor.
If CO2 were to have any measurable effect, it might be in the coldest air masses of the dead of winter where there is essentially no water vapor. At -32 deg C, -31.9 would not change anything.
What makes discussion of CO2 warming effects an academic discussion is that historically temperature rises always come before CO2 rises and, more telling, temperature can plunge while CO2 is still high, and then CO2 drops. This shows categorically and factually that CO2 cannot and has not driven the climate. And, there is no rational reason to think it would now.
It is quickly apparent that temperature drives CO2 at all time scales. Temperature peaked in 1938, CO2 peaked in the mid-1940s, temperature then dropped, and CO2 dropped.
This is very simply Henry's Law as CO2 partitions between the atmosphere and the oceans based on temperature. Furthermore, we simply cannot double the CO2 in the atmosphere - we do not have enough carbon fuels.
As CO2 partitions 50 to 1 between the ocean and the air, we would have to add 50 times the mass of CO2 that would be needed to double the CO2 in the air, to double the CO2 in the air.
We are short on carbon and could only raise it by 20% at most. We are not going to do that and it would not be a problem temperature-wise as now we are talking about thousandths or ten-thousandths of a degree of warming.
Tempest-in-a-teapot.
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Post by glc on Jun 12, 2009 9:34:25 GMT
All of this detailed discussion of CO2 warming effects is a nice exercise, but the warming that is predicted in the upper atmosphere has completely failed to occur. The concept that a trace gas would drive the climate to any measurable degree borders on laughable.
A crude approximation for the mean surface temperature of the earth is ~14 deg C (287K). By the Stefan Boltzmann Law, this temperature equates to an outgoing energy flux of ~386 w/m2. However, only ~235 w/m2 actually leaves the top of the atmosphere. If the concept is 'laughable', as you put it, you need to explain this discrepancy.
If you use the real thermodynamic alpha for CO2 and not the falsified, augmented value the IPCC created, we are talking thousandths or at most a hundredth of a degree warming with doubling of CO2.
Could you explain further?
Furthermore, water vapor is a negative forcing factor.
No it's not. What you might mean is that any feedback (possibly more wv) from an increase in CO2 could be negative. However, there is no proof that it is negative. It's more likely that feedback is zero or only slightly positive.
What makes discussion of CO2 warming effects an academic discussion is that historically temperature rises always come before CO2 rises and, more telling, temperature can plunge while CO2 is still high, and then CO2 drops. This shows categorically and factually that CO2 cannot and has not driven the climate. And, there is no rational reason to think it would now.
It might surprise you to know that many of us have already looked at these arguments and, while they are certainly worthy of consideration, have realised that issues are a little more complicated than you describe - particularly with reference to the much longer timescales.
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