Guest Post by Ira Glickstein
This series began with a mechanical analogy for the Atmospheric “Greenhouse Effect” and progressed a bit more deeply into Atmospheric Windows and Emission Spectra. In this posting, we consider the interaction between air molecules, including Nitrogen (N2), Oxygen (O2), Water Vapor (H2O) and Carbon Dioxide (CO2), with Photons of various wavelengths. This may help us visualize how energy, in the form of Photons radiated by the Sun and the Surface of the Earth, is absorbed and re-emited by Atmospheric molecules. 
DESCRIPTION OF THE GRAPHIC
The animated graphic has eight frames, as indicated by the counter in the lower right corner. Molecules are symbolized by letter pairs or triplets and Photons by ovals and arrows. The view is of a small portion of the cloud-free Atmosphere. (Thanks to WUWT commenter davidmhoffer for some of the ideas incorporated in this graphic.)
- During the daytime, Solar energy enters the Atmosphere in the form of Photons at wavelengths from about 0.1μ (micron – millionth of a meter) to 4μ, which is called “shortwave” radiation and is represented as ~1/2μ and symbolized as orange ovals. Most of this energy gets a free pass through the cloud-free Atmosphere. It continues down to the Surface of the Earth where some is reflected back by light areas (not shown in the animation) and where most is absorbed and warms the Surface.
- Since Earth’s temperature is well above absolute zero, both day and night, the Surface radiates Photons in all directions with the energy distributed approximately according to a “blackbody” at a given temperature. This energy is in the form of Photons at wavelengths from about 4μ to 50μ, which is called “longwave” radiation and is represented as ~7μ, ~10μ, and ~15μ and symbolized as violet, light blue, and purple ovals, respectively. The primary “greenhouse” gases (GHG) are Water Vapor (H2O) and Carbon Dioxide (CO2). The ~7μ Photon is absorbed by an H2O molecule because Water Vapor has an absorption peak in that region, the ~10μ Photon gets a free pass because neither H2O nor CO2 absorb strongly in that region, and one of the 15μ Photons gets absorbed by an H2O molecule while the other gets absorbed by a CO2 molecule because these gases have absorption peaks in that region.
- The absorbed Photons raise the energy level of their respective molecules (symbolized by red outlines).
- The energized molecules re-emit the Photons in random directions, some upwards, some downwards, and some sideways. Some of the re-emitted Photons make their way out to Space and their energy is lost there, others back down to the Surface where their energy is absorbed, further heating the Earth, and others travel through the Atmosphere for a random distance until they encounter another GHG molecule.
- This frame and the next two illustrate another way Photons are emitted, namely due to collisions between energized GHG molecules and other air molecules. As in frame (2) the Surface radiates Photons in all directions and various wavelengths.
- The Photons cause the GHG molecules to become energized and they speed up and collide with other gas molecules, energizing them. NOTE: In a gas, the molecules are in constant motion, moving in random directions at different speeds, colliding and bouncing off one another, etc. Indeed the “temperature” of a gas is something like the average speed of the molecules. In this animation, the gas molecules are fixed in position because it would be too confusing if they were all shown moving and because the speed of the Photons is so much greater than the speed of the molecules that they hardly move in the time indicated.
- The energized air molecules emit radiation at various wavelengths and in random directions, some upwards, some downwards, and some sideways. Some of the re-emitted Photons make their way out to Space and their energy is lost there, others back down to the Surface where their energy is absorbed, further heating the Earth, and others travel through the Atmosphere for a random distance until they encounter another GHG molecule.
- Having emitted the energy, the molecules cool down.
DISCUSSION
As in the other postings in this series, only radiation effects are considered because they are the key to understanding the Atmospheric “Greenhouse Effect”. I recognize that other effects are as important, and perhaps more so, in the overall heat balance of the Earth. These include clouds which reflect much of the Sun’s radiation back out to Space, and which, due to negative feedback, counteract Global Warming. Other effects include convection (wind, thunderstorms, …), precipitation (rain, snow) and conduction that are responsible for transferring energy from the Surface to the Atmosphere. It is also important to note that the Atmospheric “Greenhouse Effect” and a physical greenhouse are similar in that they both limit the rate of thermal energy flowing out of the system, but the mechanisms by which heat is retained are different. A greenhouse works primarily by preventing absorbed heat from leaving the structure through convection, i.e. sensible heat transport. The greenhouse effect heats the earth because greenhouse gases absorb outgoing radiative energy and re-emit some of it back towards earth.
That said, how does this visualization help us understand the issue of “CO2 sensitivity” which is the additional warming of the Earth Surface due to an increase in atmospheric CO2? Well, given a greater density of CO2 (and H2O) molecules in the air, there is a greater chance that a given photon will get absorbed. Stated differently, a given photon will travel a shorter distance, on average, before being absorbed by a GHG molecule and be re-emitted in a random direction, including downwards towards the Surface. That will result in more energy being recycled back to the Surface, increasing average temperatures a bit.
Ira Glickstein says:
April 3, 2011 at 6:16 pm
Hans says:
April 2, 2011 at 12:57 pm
Backradiation acts as a perpetuum mobile …”
I finally figured out where you have gone wrong here. You think that temperature, per se, is the same as energy.”
No I don’t, intensive versus extensive properties.
“You think that I assume the metal box in which I hung that 400K soldering iron will get up to 399K or so. I assume nothing of the sort. The box is larger than the soldering iron and much larger than the tip. Indeed, if the box was the size of a tool box, you might be able to hold it in your hands and find it quite warm, but not burning. The tip, of course, would burn your fingers.”
Agreed, but following your iron in a box idea you imply that the greenhouse effect heats up the core of the sun right?
Steve – as in the example of the plants, visible energies are used by us. UV gives us Vitamin D, etc. There’s a whole lot more to life than heat in and heat out.. Near IR is used in medical therapies, it does not burn the cells targetted…
Nor does it burn the finger when it is used in diagnosis – http://equipmentexplained.com/physics/respi_measurements/oxygen/oximeter/pulse_oximeter.html
Visible light is not a good penetrator of the body, but the longer wave length of red can be used with Near IR to test oxygen levels in the blood. This uses red visible at approximately 650 nm and Near IR at 950 nm. It’s a fascinating read, real life scientific application our of lights real properties understood. So, Note Well, it makes adjustments for basic laws because real life is not an imaginary ideal, and if it didn’t make the necessary adjustments the results would be nonsensical.
Carbon Dioxide does not rise up into the atmosphere to diffuse throughout it becoming thoroughly mixed by Brownian motion, nor does it travel through the atmosphere at superspeeds of the imaginary unreal ideal gas..
..only in Cloud Cuckoo land.
Your ridicule is mis-directed, on par with your mis-application of the laws of physics. Step back through the mirror, come back to the real world.
Myrrh says:
April 4, 2011 at 11:30 am
Davidmhoffer -Avoiding giving me the specific information I have asked for is no reply.>>>
Avoiding the specific information that you have been given is proof of the existance of a Magical Armour of Density. Although it does raise the possibility of the existance of a Magical Armour of Avoidance.
Let me see if I can answer the question — “which came first, the chicken or the heat”. To understand this, you need to look specifically where the energy goes.
Let me make several assumption (none of which is absolutely critical, but which give us numbers to work with):
* a spherical, ε = 1 chicken with a surface area of = 0.05 m^2.
* a 500 W heater for the chicken which we can turn on or off (the exact nature doesn’t matter, but an electrical resistance heater would be simplest).
* an un-insulated (and unheated!) oven with a surface area of 1 m^2 (ie 20x larger than the chicken). This oven has ε = 1 inside and out.
* an ε = 1 room which is held at 300 K (room temperature).
* the spaces between these are all well insulated, so there is no conduction of heat — only radiation.
* all results are after equilibrium is reached.
If the chicken was sitting in outer space far from any star or planet (ie not in the oven or room), it would eventually reach an equilibrium situation where it would radiate 500 W, which would be a temperature of 648 K (from BB radiation laws P = εσAT^4). If the heater was turned off, the temperature would head toward 0 K ( or 2.7 K since there is a LITTLE IR radiation in space).
Suppose the chicken was placed inside the oven, and the oven is in outer space. With the heater running, the oven will have to eventually come to equilibrium radiating 500 W from its 1 m^2, which would require a temperature of 306 K for the oven surface. The oven at this temperature will radiate 25 W to the chicken. The chicken receives 25 W from the oven walls and 500 W from the heater; its temperature must be 656 K (ie 8 K warmer than if the chicken was “bare”).
Suppose the chicken w/heater was placed inside the oven, and the oven is placed inside the room. The room will radiate 459 W to the oven. The oven needs to radiate this 459 W AND the 500 W from the heater = 959 W, which would be 361 K (ie the outside of the oven will be 61 K above room temp). The oven at this elevated temp will radiate 48 W to the chicken, so the chicken radiates 548 W, which requires a temp of 663 K (ie 7 K warmer than the oven in out space, and 15 K warmer than the bare chicken).
Finally, suppose the chicken without heater was placed inside the oven, and the oven is placed inside the room. The room @ur momisugly 300 K will radiate 459 W to the oven and the oven @ur momisugly 300 K will radiate 459 W to the room. The oven 23 W to the chicken and the chicken will radiate 23 W to the oven. Everything will be @ur momisugly 300 K
So ..
* Without a heater, the chicken will be at the temperature of the surroundings
* With a heater, the chicken will have some temperature above the surroundings. How much depends on the situation, but in no case will the temperature grow without bounds, and in no case will the feedback grow without bounds.
NOTE: I tried one more case — the “oven” wrapped closely around the chicken (but not touching). In this case at equilibrium the oven radiates 500 W outward from its 0.05 m^2 and 500 W inward (the maximum possible). The chicken then gets 500 W from the oven and 500 W from the heater. The oven reaches 656 K (he same as the chicken by itself in outer space), while the the chicken raises to a temperature of 771 K. This is the highest the chicken could reach without either powering up the heating element or adding more layers to the oven or adding other insulation.
Of course, the original “powerless chicken oven” is absurd, violating basic physics. The powerless oven DOES help keep the chicken warm IF the chicken has some external power source, just like the powerless atmosphere helps keep the earth warm if the earth has some external power source (ie the sun).
RJ; Richard E Smith;
“I know David does not think that this can happen (obviously) but it is not apparent to me why not, given that he believes that radiation from the surroundings of the chicken can heat the chicken up thereby adding more radiation from the chicken and so on – a perpetuum mobile”.
Agree. I’m still waiting for an explanation on this point.>>>
Perhaps this will help? Add up the numbers in my model at each step. Remember that the Oven was modeled as having 10 times the surface area of the chicken, so the watts below are TOTAL not per meter squared.
Chicken Oven
0 0
+500 => +250
+250 => +125
+125 => + 62.5
+ 62.5=> + 31.25
+ 31.25=>+15.625
+15.625=>+7.8125
+7.8125 => +3.906
3.906 => +1.953
1.953 =>.977
.977 =>.488
.488 => .244
.244 => .122
TOTAL WATTS OUT FROM OVEN = 499.76
Continue the series for as long as you wish, you will eventually
get to 499.9999…. watts coming out of the oven to the outside, matching exactly the watts going into the chicken in the first place.
+2.1 => 1.0
Beam of energy going into Oven = 500 watts
250+125+62.5+31.25+16.5+8.25+4.1+2+1= 500.6
If I’d bothered with the decimal places exactly it would have come
Mods!
Aw fiddlesticks, strike those last 4 lines, I didn’t run enough decimal places the first time got the wrong numbers, and then forgot to snip it off the end of the comment.
“The heat we feel from a fire is THERMAL IR. ”
This might be a big part of problem. The “established physics” typically defines “thermal IR” as 3 um – 15 um. A hot fire at 1/3 the temperature of the sun will emit only about 30% of its energy as “thermal IR” while the rest will be almost entirely “non-thermal IR”. Cooler fires will have a larger proportion of “thermal IR” but a significant part of the IR we feel will be other than thermal IR
It is always important to have common definitions for terms in a discussion, like “thermal IR” or “heat”.
Your getting closer Myrrh. You are admitting that there is non-reflected visible light responsible for… well, ultimately, just about every chemical bond in every organic molecule. So that’s some of your non-reflected energy of visible light, stored among all the biomass of earth (and it get’s released as heat when you burn it).
Now, go back to imagining the difference between a mirror-covered landscape and the actual landscape for the entire earth. Plants don’t cover every surface, right? Have you bothered to try and calculate, just a little, the energy difference in reflected visible light between a mirror Pacific Ocean and the actual Pacific Ocean?
Hans says:
No, Hans. We are talking about a case where power is being supplied constantly. If power going in at a rate of 100 W, i.e., 100 J / s and power is going out at a rate of 10 J / s, then after 1 second, the amount of energy would have increased by 90 J, after 2 sec by 180 J and so on. Hence, energy would be building up over time, which would result in the temperature of the object rising. You can’t just set the temperatures independently…If you are putting a fixed amount of power in, the temperatures will adjust until they find the point where the power being emitted equals that coming in.
The statement of the problem is not that the sun sends a one-time contribution of 240 J/m^2 of energy to the earth. It sends (on average) 240 J/m^2 every second. If the earth doesn’t send back (out into space) energy at an average rate of 24o J/m^2 every second then the energy of the earth will increase, raising its temperature and (by the Stefan-Boltzmann Law) increasing the rate at which it emits energy until it is sending 240 J/m^2 every second back out into space.
Okay…Nice analogy, Hans. Except you have made an error in solving the problem because you are mixing two things here, one being volume and one being the energy. This analogy, when looked at properly, actually allows you to understand why conservation of energy means that power in = power out.
Power is energy per unit time. Likewise, volume flow rate is volume per unit time. So, the analogy with having conservation of energy in the systems we’ve been talking about is having conservation of volume in the water flowing in a pipe analogy. (It is NOT having a constant amount of power being used to drive a pump…that mixes energy and volume.) So, for an incompressible fluid completely filling a pipe, the volume flow rate must indeed be the same going in as coming out. If it is not, fluid will be piling up somewhere in between, which it can’t do for an incompressible fluid in a pipe. (If the fluid is compressible, then it is mass and not volume that must be conserved.) For example, if there was 2 m^3 /s of fluid going into a pipe in steady flow, there has to be 2 m^3 /s coming out. Thus, in your example, if you are forcing fluid to go into the pipe at 2 m^3 / s and you put a constriction in the pipe but continue to put 2 m^3 /s of fluid into the pipe, you will continue to get 2 m^3 /s of fluid out of the pipe.
What your point-of-view would say, by contrast, is that you could be putting 2 m^3 / s into the pipe but only be getting 1 m^3 s out of the pipe. However, that would be impossible because the volume of fluid must be conserved. If you study this example and understand it, you will understand how Conservation of Volume implies that the volume flow rate in has to equal the volume flow rate out just as Conservation of Energy implies that the power in has to equal the power out.
No…At that particular instant of time there will not be any power being emitted. However, the situation that you describe cannot persist because the rate at which energy flowing in (i.e., the power) does not equal the rate at which it is leaving, so the temperature of the object will rise and then the temperature difference between the object and the shell surrounding it will no longer be zero.
Hans: To be honest, I am beginning to doubt that you and Myrrh are really materially-different. Please show me otherwise by actually trying to open up your mind and learn something.
Hans asks @ur momisugly April 4, 2011 at 2:12 pm
“Agreed, but following your iron in a box idea you imply that the greenhouse effect heats up the core of the sun right?”
A point of clarification — are you asking about the green house effect of the sun’s atmosphere helping keep the core of the sun warm? In which case, yes, the insulating and “greenhouse properties” of the sun’s atmosphere definitely help keep the temperature of the core higher than it would be without those layers. (As opposed asking if the earth’s greenhouse effect and thermal radiation from the earth helping keep the sun warm, in which case it would in principle, but the effect would be such an infinitesimal amount that it would not be measurable.)
Let us do it this way to see if you can be convinced. Forget about emissions and consider cold cash instead.
OK, we have three characters, Mr. Heat Source, Miss Chicken, and Mr. Wall.
DAY #1: In the morning, Mr. Heat Source gives Miss Chicken $500. In the afternoon, she gives the $500 to Mr. Wall. (So Miss Chicken has zero cash in the afternoon.) That evening Mr. Wall blows half ($250) on booze and gives the remainder ($250) back to Miss Chicken. (So she has $250 in the late evening of that day.)
DAY #2: In the morning, Mr. Heat Source gives Miss Chicken another $500. She has $250 left from the previous day, so she now has $750. In the afternoon, she gives the $750 to Mr. Wall. (So Miss Chicken has zero cash in the afternoon.) That evening Mr. Wall blows half ($375) on booze and gives the remainder ($375) back to Miss Chicken. (So she has $375 in the late evening of that day.)
DAY #3: In the morning, Mr. Heat Source gives Miss Chicken another $500. She has $375 left from the previous day, so she now has $875. In the afternoon, she gives the $875 to Mr. Wall. (So Miss Chicken has zero cash in the afternoon.) That evening Mr. Wall blows half ($437.50) on booze and gives the remainder ($437.50) back to Miss Chicken. (So she has $437.50 in the late evening of that day.)
DAY #4: In the morning, Mr. Heat Source gives Miss Chicken another $500. She has $437.50 left from the previous day, so she now has $937.50. In the afternoon, she gives the $937.50 to Mr. Wall. (So Miss Chicken has zero cash in the afternoon.) That evening Mr. Wall blows half ($468.75) on booze and gives the remainder ($468.75) back to Miss Chicken. (So she has $468.75 in the late evening of that day.)
This goes on for many days. I hope you can see that Miss Chicken’s cash at the end of each day has been increasing. It went from $250 in the late evening of the first day to $468.75 on the late evening of the fourth day. Her cash in the morning, which she gives to Mr. Wall each afternoon, has gone from $500 the first day to nearly twice that, $937.50 on the fourth day.
If we continue this tale long enough, things will stabilize, and Miss Chicken’s cash in the morning that she gives to Mr. Wall in the afternoon, will be around $1000. Mr. Wall, for his part, will be blowing about $500 on boooze each evening. So, money in = money out. Mr. Heat Source will give $500 each morning and Mr. Wall will blow the same amount each late evening. Miss Chicken will be have an account of $1000 each morning and early afternoon, which is twice what Mr. Heat Source gives her each morning.
No cash had been created by the transactions between Miss Chicken and Mr. Wall. All meets with the approval of the accountants.
Now do you get it? Mr. Heat Source is the Sun. Miss Chicken is the Earth, and Mr. Wall is the Atmosphere. I hope this convinced you. Richard E Smith
David,
One small comment — I think your oven infinite series above actually requires the “oven” to be close around the chicken. If the oven is 10x more area, then if the oven emits 250 W out into space, it will only send 25 W back to the chicken (since the chicken is 1/10 as much area as the oven. By the time the oven is emitting 500 W to space, it will be emitting 50 W to the chicken.
The energy balance works in either case. If the system has reached equilibrium:
10x AREA OVEN
Chicken receives 550 W (500 W from heater; 50 W from oven)
Chicken sends out 550 W (all to the oven)
NET = 0 W
Oven receives 550 W (from chicken)
Oven sends out 550 W (500 to outer space; 50 to the chicken)
NET = 0 W
“outer space” receives 500 W (from oven)
“outer space” sends out 500 W (electrical energy to chicken)
NET = 0 W
1x AREA OVEN
Chicken receives 1000 W (500 W from heater; 500 W from oven)
Chicken sends out 1000 W (all to the oven)
NET = 0 W
Oven receives 1000 W (from chicken)
Oven sends out 1000 W (500 to outer space; 500 to the chicken)
NET = 0 W
Tim,
Certainly!
At day’s end, the oven must always heat up enough to emitt 500 watts to the outside to balance the 500 watts going in from the beam.
Tim Folkerts says:
April 4, 2011 at 4:12 pm
Re: “The heat we feel from a fire is THERMAL IR.”
This might be a big part of problem. The “established physics” typically defines “thermal IR as 3 um-15 um. A hot fire at 1/3 temperature of the sun will emit only about 30? of its energy as “thermal IR” while the rest will be almost entirely “non-thermal IR”. etc.
Nope, the big part of the problem here is that non-thermal IR is not felt as heat. If you can feel heat you are feeling thermal IR. Adjust your um’s accordingly.
AGWScience Energy Balance has UV Visible and Near IR – Near IR is not thermal. See NASA page for “ESTABLISHED PHYSICS”. You cannot feel Near IR, it is not hot. I repeat, in established physics, Near IR is not hot. You cannot feel it.
You cannot feel Visible light, it is not hot. You cannot feel UV, it is not hot.
It is always important to have common definitions for terms in a discussion, like “thermal IR” or “heat”.
Damn right. Established physics says the heat we feel from fire and sun is Thermal IR.
Adjust your thinking accordingly.
Now answer my question.
Ditto Steve for the above. And, The AGWScience Energy Budget says that Solar, UV, Visible and Near IR, heat the Earth. These are not Thermal energies. Show how these non-thermal energies produce the updwelling Thermal IR claimed. As Trenberth diagram I posted, and Ira; the claim is that it is these SPECIFIC energies which HEAT the EARTH and convert to THERMAL IR to upwell. Land and Sea both.
Stick with the question I’m asking, don’t get distracted.
I am demanding actual proof that these non-thermal energies do what it says in the AGWScience Energy Budget. I repeat. These are not Thermal IR in ESTABLISHED, TRADITIONAL PHYSICS.
And, I don’t give a damn how many AGWScience reference you give to claim that traditionally non-thermal energies are thermal, they’re not. That AGWScience has corrupted traditional understanding is the REAL PROBLEM here. I am getting weary of explaining this to you. The NASA page describes the difference. The newworldencylopedia admits it is still traditional teaching.
If you can feel heat, you are feeling Thermal IR. Full stop.
Now, answer my question.
Ira
Re your money example above
But does energy work this way. Energy is more like a teacher (sun) passing knowledge to a student (earth). The student can only take in so much knowledge and can not increase the teachers knowledge by passing the same knowledge back. But the student can increase the knowledge of another student (CO2) with less knowledge etc.
IMHO the chicken and oven example in a very simple way demolishes the GHG theory as I understand it. This oven is impossible yet the GHG theory seems to be based on this concept.
If the GH theory is correct and an 100% CO2 environment reflected back 100% of the radiation (rather than 50% or less). What then. The planet would continue heating even with only one days energy from the sun. This is clearly nonsense yet seems to be the concept the GHG theory is built on.
Either CO2 reflects back radiation from the earth further heating the earth or it does not. In simple terms I can not see how the oven example is not correct. And complex explanations do not change this. Nor does the money example.
I agree with the slayers book as others seem to on here. This thread has only reinforced my support for the sections on backradiation in this book.
RJ says: “IMHO the chicken and oven example in a very simple way demolishes the GHG theory as I understand it. ”
Then I humbly suggest that you do not, indeed, understand it. Analogies — “energy is like money” or “energy is like knowledge” — are just scratching the surface. Analogies are great for getting across some simple ideas, but you also have to know what is good and what is bad about the analogies to use them to make any conclusions.
To really understand, you need to be able really use the equations. For instance, I gave some specific numbers for some specific cases a day ago based on my understanding of physics. The results agree with David’s approach using infinite series. They show clearly that the temperature of the chicken in the unheated oven is indeed warmer than the chicken outside the oven. They show clearly that the money analogy is better then the knowledge analogy.
If someone wants to look for an error in the calculations and show how the calculations are wrong, I’d be happy to discuss it. That is how science moves ahead. Which of my numerical results are specifically wrong and what should they be instead? The simple truth is that you really need to be able to do these calculations to seriously enter into the conversation.
If, instead, someone wants to simply say something like “I heard once that only thermal IR can be felt” even in the face of both experimental evidence and theoretical results — well — there is not much that can be done. If someone with such opinions wanted to calculate (based on any reasonable assumptions he wanted to make) how much energy he received on a sunny day from various wavelengths of the solar EM radiation and from various wavelengths of the earth’s EM radiation, and then show how only the wavelengths between 3 um and 15 um can elicit a response from temperature-sensing nerves, then I would be willing to take the conversation further.
RJ, IMHO you are wrong here on a couple of levels. (1) Energy/Matter cannot be created nor destroyed, so it is not at all like knowledge, and (2) I have learned a great deal from my students in the undergrad and grad system engineering courses I have taught at Binghamton University and currently teach online at the University of Maryland. Heck, I even learned from my students at the Brandeis University Summer Odyssey and they were “merely” bright High School students who elected to spend a month of ther summer vacations to get a taste of college. I learned from all of them despite the fact of my decades of successful experience doing real work as a System Engineer.
I learn continually in my interactions with others – including especially here at WUWT. I have probably learned more in doing this “Visualizing” series than many of the WUWT readers, and I have thanked those who helped me understand better. It is never too late!
I hope you and some others who have fixed, non-scientific opinions about the role of certain gases in the Atmosphere in keeping the Earth at a livable range of temperatures would take the opportunity to learn the accepted science. Accepting the truth of so-called “greenhouse” gases (GHG) and the small contribution of our burning of fossil fuels and land use changes to mean temperature levels does not mean that you subscribe to the outlandish Catastrophic CAGW theories of the official climate Team. The only way to fight darkness is with light. You can’t fight darkness with greater darkness.
Good luck!
Frankly, Myrrh, I have no idea what question it is that you want answered.
So … phrase your question and/or hypothesis in precise scientific/mathematical language. Unless otherwise stated, I will assume you agree with wikipedia for definitions of any terms you use (eg “thermal IR” or “heat”) and you agree with wikipedia for equations (eg Stefan-Boltzmann law). [Not that wikipedia provides definitive knowledge, but at least it gives us a starting point for further discussion.]
RJ says:
As Tim has pointed out to you, analogies are only useful to the extent that they illustrate actual laws of physics. To the extent that they illustrate imaginary laws of physics, they are worse than useless. Ira’s analogy illustrates the Law of Conservation of Energy.
Your analogy, as near as I can tell, illustrates an imaginary physical law which, for lack of a better name, I’ll call the “Magical 2nd Law of Thermodynamics”. The “Magical 2nd Law” apparently says that if you put a cold object near a hot object, the cold object magically detects this and refuses to emit radiation toward the hot object. Or maybe it states that the cold object emits radiation toward the hot object but the hot object refuses to absorb it. The “Magical 2nd Law” has absolutely no experimental verification and, in fact, a lot of experimental evidence showing that it is nonsense. (It also represents a bizarre theoretical view of the universe, for whatever that is worth.)
By contrast, the actual 2nd Law of Thermodynamics would say that the cold and hot objects both emit and absorb radiation but that the amount of radiation absorbed by the hot object from the cold object is always less than the amount of radiation absorbed by the cold object from the hot object.
One fact it is perhaps worth making explicit: The laws of radiative transfer automatically satisfy the 2nd Law when applied correctly. If you find yourself applying the 2nd Law to somehow contradict something that the laws of radiative transfer have told you, this is an indicate that you are applying the Magical 2nd Law and not the actual 2nd Law (or, I suppose, that you applied the laws of radiative transfer incorrectly).
Since you have had it explained in gory detail why this is not the case, one can only guess that you cling to this belief because its suits what you want to believe rather than for any rational reason.
Here, you have gone off the rails right from the get-go. The CO2 does not reflect radiation. What happens is that the CO2 in the atmosphere absorbs radiation and then as a result of its having a nonzero temperature, it emits radiation. While you can sometimes get away with imagining it being almost as if the CO2 reflected the radiation, such a point of view ultimately leads you astray, especially when you try to get quantitative about it.
Frankly, that is sad. What you are telling us is that you have no ability to distinguish between actual science and pseudoscientific garbage when the pseudoscience is something that you want to believe. That is something to be embarrassed about, not proud of.
RJ;
If the GH theory is correct and an 100% CO2 environment reflected back 100% of the radiation (rather than 50% or less). What then.>>>
1. It doesn’t reflect. It absorbs and radiates.
2. % of the environment which is CO2 has nothing to do with how much goes up and how much down. It absorbs some amount. It radiates that amount in a random direction. Random meaning about the same amount up as down. Sideways mostly a net cancellation. The % only has meaning in terms of magnitude, not ratio of up vs down.
RJ;
Either CO2 reflects back radiation from the earth further heating the earth or it does not. >>>
It does not.
As has been explained multiple times, it does not “reflect”.
RJ;
I agree with the slayers book as others seem to on here. This thread has only reinforced my support for the sections on backradiation in this book.>>>
Then you have joined the ranks of the skeptics for all the wrong reasons. You’re as misguided by what you wish to believe as are your kindred spirits in the warmist community shouting that the sky is falling, not because the science says so, but because they wish to believe it.
Tim Folkerts says:
April 4, 2011 at 5:34 pm
Hans asks @ur momisugly April 4, 2011 at 2:12 pm
“Agreed, but following your iron in a box idea you imply that the greenhouse effect heats up the core of the sun right?”
…asking if the earth’s greenhouse effect and thermal radiation from the earth helping keep the sun warm, in which case it would in principle, but the effect would be such an infinitesimal amount that it would not be measurable.”
Yes, infinitesimal. But as you say it’s the principle, and that is what I want to have confirmed.
Ira, please comment.
Joel, please comment.
Myrrh;
Ditto Steve for the above. And, The AGWScience Energy Budget says that Solar, UV, Visible and Near IR, heat the Earth. These are not Thermal energies. Show how these non-thermal energies produce the updwelling Thermal IR claimed.>>>
As has been explained to you multiple times, all frequencies carry energy. Yet you continue to scream about frequencies being non-thermal. non-thermal doesn’t mean 0 energy. That you can’t “feel” outside of the range of thermal doesn’t mean it doesn’t carry energy. You cling to this concept, shout it repeatedly, because without this one piece of stupidity, your entire position collapses into a heap of smoldering b*****it.
Is this a consequence of your Armour of Density, Invisibility, or Avoidance?
What gives the CO2 molecule its ability to absorb and (as a consequence of physics) re-radiate radiation in infrared wavelengths that are important to the atmosphere and the climate is its number of atoms: three.’ “More than two” is the crucial concept here, because the other important infrared-capturing gases in the atmosphere also have three or more atoms in their molecules. When a gas has three or more atoms, it has modes of vibration inherent in its shape that can resonate with the frequencies of climate-affecting infrared waves. The matching enables the greenhouse molecules to intercept those waves and absorb their energy. Single atoms and two-atom molecules do not have those particular resonant modes. Just a few examples of other greenhouse gases make the point, if you count their atoms: water vapor (H2O)1 methane (CH4), nitrous oxide (N2O), and ozone (03). It is estimated that the earth would be 60f cooled without greenhouse gases. CO2 is the most variable of the greenhouse gases so it determines the tempurature of the biosphere. It is, in a natural situation, varied by other factors i.e. it follows global temp swings and that is because of the lag from the ocean’s heat collecting ability.