Post by kiwistonewall on Sept 4, 2008 11:32:45 GMT
Executive Summary: Greenhouse Warming is a simple and well understood process. The effect appears to have been obfuscated by mixing in climate effects and calling the entire process Greenhouse warming or forcing.
This would be analogous to taking Gravity, and applying multidimensional strings, electromagnetism, and a dozen other concepts, then stating that you can't understand Gravity unless you have a supercomputer. But remove all the stuff which isn't gravity, and you get back to good old Gravity.
The greenhouse effect is very simple, and is NOT an effect that primarily traps heat in the atmosphere, but rather returns a portion of the energy back to the earth.
We can treat the Earth's surface and atmosphere as a single point surface and ignore convection and otherwise, as all these other effects are the climate system as a whole. The success of the simple treatment is covered in the pro-AGW reference:
www.aip.org/history/climate/Radmath.htm
(all quotes here from the above link)
when they say
OK, we've established that the greenhouse effect works really well treated quite simply. However, all the forcing theories involve dividing up the atmosphere into tiny layers. These theories come & go as models are tweaked, but basically fail to predict anything other than a forcing which, as things stand, is unproven, if not already disproved. Unfortunately, the models can change so fast by a tweak in a parameter here or there, that proof/disproof becomes somewhat meaningless.
So, back to the simple treatment:
Essentially, short wave (UV, visible light) enters the atmosphere and is re-radiated from Earth back toward space as infra-red.
Greenhouse gases absorb various portions of the IR spectrum and re-radiate the energy in all directions (scattering)
Molecules that absorb IR at various frequencies do this by making a quantum transition to a higher energy state. Any higher energy state is (of course) a higher temperature, since temperature is the average motion of molecules. After a period of time, the C02 molecule will emit the radiation normally at the same frequency, unless some of that energy has been lost to another molecule through molecular collision. At this point, the vibrational energy is lower, so, by definition, temperature is lower. The greenhouse effect IS the energy being returned toward Earth, not a warming of the various gases. If the atmosphere layers warm, then energy is NOT being scattered, and the Greenhouse effect isn't occurring.
The emission of energy is random, in any direction. Once there is enough greenhouse gas absorbing any IR frequency, all the energy at that frequency will be fully scattered.
Note that the IR emitted will be reabsorbed by other C02 molecules over and over again. But the random nature of this means as much is sent back Earthwards (to heat the Earth or its atmosphere) as is sent out to space. Once we get 100% absorption, the number of times the IR radiation is absorbed or re-emitted is irrelevant.
With conservation of energy, if any layer of the atmosphere is warmed, then less energy will get back to the Earth. They can't have it both ways, or count the energy twice. Its the same energy from the sun. If more heats the atmosphere, less reaches the surface.
Its almost as if they've taken the effect of greenhouse warming, mixed in normal climate factors, created a composite and called it forcing. Treating things twice (or many times.) With no real experiments, just running around looking for correlations to the models. Since there are many models, then they'll inevitably find some agreement with some climatic factor.
They got themselves confused, or they've created a fog. It appears a bit slight of hand.
Really? How did we work out the rules if we didn't do the experiments. For Chemists and Physicists (or Physical Chemists - myself) this is a well understood area. I admit that chaotic climate systems are complex, but principles like GW are well understood unless obfuscated to put off the layman.
Which means, "hey look folk, its too hard and you haven't got our supercomputers, so TRUST US" -
But any of their theoretical model layers can be tested in the laboratory. For some reason, they don't think they need to.
Questions needing Answers:
1. Are we at 100% Absorption? (For CO2: See Useful Climate Links #4) Maybe, maybe not, I've not seen the data from an AGW perspective.
2. Are there experiments proving the forcing theories? (Not Model-climate correlations, but actual radiation through gas & measuring changes. Hey, with all that money they could build a super tower (or deep mine) and model segments of the atmosphere- a bit like CERN - and when are they going to start THAT up! )
Finally, I KNOW that climate modeling is complex. But the Greenhouse effect in and of itself isn't. Let's not confuse the issue. Science has progressed by Abstraction, separating out complex systems into individual processes and understanding each process in turn. Never by complicating the process so that genuine experimentation is impossible.
This would be analogous to taking Gravity, and applying multidimensional strings, electromagnetism, and a dozen other concepts, then stating that you can't understand Gravity unless you have a supercomputer. But remove all the stuff which isn't gravity, and you get back to good old Gravity.
The greenhouse effect is very simple, and is NOT an effect that primarily traps heat in the atmosphere, but rather returns a portion of the energy back to the earth.
We can treat the Earth's surface and atmosphere as a single point surface and ignore convection and otherwise, as all these other effects are the climate system as a whole. The success of the simple treatment is covered in the pro-AGW reference:
www.aip.org/history/climate/Radmath.htm
(all quotes here from the above link)
when they say
For understanding the greenhouse effect itself, one-dimensional radiative-convective models remained central. Treating the entire planet as a single point allowed researchers to include intricate details of radiation and convection processes without needing an impossible amount of computing time.(20) These models were especially useful for checking the gross effects of influences that had not been incorporated in the bigger models. As late as 1985, this type of schematic calculation gave crucial estimates for the greenhouse effect of a variety of industrial gases (collectively they turned out to be even more important than CO2).(21)
Another example was a 1978 study by James Hansen's NASA group, which used a one-dimensional model to study the effects on climate of the emissions from volcanic eruptions. They got a realistic match to the actual changes that had followed a 1968 explosion. In 1981, the group got additional important results by investigating various feedback mechanisms while (as usual) holding parameters like relative humidity and cloudiness fixed at a given temperature. Taking into account the dust thrown into the atmosphere by volcanic eruptions plus an estimate of solar activity variations, they got a good match to modern temperature trends.(22)
Primitive one-dimensional models were also valuable, or even crucial, for studies of conditions far from normal. Various groups used simple sets of equations to get a rough picture of the basic physics of the atmospheres of other planets such as Mars and Venus. When they got plausible rough results for the vastly different conditions of temperature, pressure, and even chemical composition, that confirmed that the basic equations were broadly valid. Primitive models could also give an estimate of how the Earth's own climate system might change if it were massively clouded by dust from an asteroid strike, or by the smoke from a nuclear war.
Another example was a 1978 study by James Hansen's NASA group, which used a one-dimensional model to study the effects on climate of the emissions from volcanic eruptions. They got a realistic match to the actual changes that had followed a 1968 explosion. In 1981, the group got additional important results by investigating various feedback mechanisms while (as usual) holding parameters like relative humidity and cloudiness fixed at a given temperature. Taking into account the dust thrown into the atmosphere by volcanic eruptions plus an estimate of solar activity variations, they got a good match to modern temperature trends.(22)
Primitive one-dimensional models were also valuable, or even crucial, for studies of conditions far from normal. Various groups used simple sets of equations to get a rough picture of the basic physics of the atmospheres of other planets such as Mars and Venus. When they got plausible rough results for the vastly different conditions of temperature, pressure, and even chemical composition, that confirmed that the basic equations were broadly valid. Primitive models could also give an estimate of how the Earth's own climate system might change if it were massively clouded by dust from an asteroid strike, or by the smoke from a nuclear war.
OK, we've established that the greenhouse effect works really well treated quite simply. However, all the forcing theories involve dividing up the atmosphere into tiny layers. These theories come & go as models are tweaked, but basically fail to predict anything other than a forcing which, as things stand, is unproven, if not already disproved. Unfortunately, the models can change so fast by a tweak in a parameter here or there, that proof/disproof becomes somewhat meaningless.
So, back to the simple treatment:
Essentially, short wave (UV, visible light) enters the atmosphere and is re-radiated from Earth back toward space as infra-red.
Greenhouse gases absorb various portions of the IR spectrum and re-radiate the energy in all directions (scattering)
Molecules that absorb IR at various frequencies do this by making a quantum transition to a higher energy state. Any higher energy state is (of course) a higher temperature, since temperature is the average motion of molecules. After a period of time, the C02 molecule will emit the radiation normally at the same frequency, unless some of that energy has been lost to another molecule through molecular collision. At this point, the vibrational energy is lower, so, by definition, temperature is lower. The greenhouse effect IS the energy being returned toward Earth, not a warming of the various gases. If the atmosphere layers warm, then energy is NOT being scattered, and the Greenhouse effect isn't occurring.
The emission of energy is random, in any direction. Once there is enough greenhouse gas absorbing any IR frequency, all the energy at that frequency will be fully scattered.
Note that the IR emitted will be reabsorbed by other C02 molecules over and over again. But the random nature of this means as much is sent back Earthwards (to heat the Earth or its atmosphere) as is sent out to space. Once we get 100% absorption, the number of times the IR radiation is absorbed or re-emitted is irrelevant.
With conservation of energy, if any layer of the atmosphere is warmed, then less energy will get back to the Earth. They can't have it both ways, or count the energy twice. Its the same energy from the sun. If more heats the atmosphere, less reaches the surface.
Its almost as if they've taken the effect of greenhouse warming, mixed in normal climate factors, created a composite and called it forcing. Treating things twice (or many times.) With no real experiments, just running around looking for correlations to the models. Since there are many models, then they'll inevitably find some agreement with some climatic factor.
They got themselves confused, or they've created a fog. It appears a bit slight of hand.
"No branch of atmospheric physics is more difficult than that dealing with radiation. This is not because we do not know the laws of radiation, but because of the difficulty of applying them to gases." — G.C. Simpson(1)
Really? How did we work out the rules if we didn't do the experiments. For Chemists and Physicists (or Physical Chemists - myself) this is a well understood area. I admit that chaotic climate systems are complex, but principles like GW are well understood unless obfuscated to put off the layman.
Looking for a complete explanation of greenhouse warming, equations and all? You won’t find it here or anywhere on the Web: first you have to fully grasp at least one good textbook, and even then you can only see how climate may change by running the equations on a large computer model that takes into account all the details of crucial factors like clouds and ocean circulation.
Which means, "hey look folk, its too hard and you haven't got our supercomputers, so TRUST US" -
But any of their theoretical model layers can be tested in the laboratory. For some reason, they don't think they need to.
Questions needing Answers:
1. Are we at 100% Absorption? (For CO2: See Useful Climate Links #4) Maybe, maybe not, I've not seen the data from an AGW perspective.
2. Are there experiments proving the forcing theories? (Not Model-climate correlations, but actual radiation through gas & measuring changes. Hey, with all that money they could build a super tower (or deep mine) and model segments of the atmosphere- a bit like CERN - and when are they going to start THAT up! )
Finally, I KNOW that climate modeling is complex. But the Greenhouse effect in and of itself isn't. Let's not confuse the issue. Science has progressed by Abstraction, separating out complex systems into individual processes and understanding each process in turn. Never by complicating the process so that genuine experimentation is impossible.