Guest post By Ben Herman and Roger A. Pielke Sr.
During the past several months there have been various, unpublished studies circulating around the blogosphere and elsewhere claiming that the “greenhouse effect” cannot warm the Earth’s atmosphere. We would like to briefly explain the arguments that have been put forth and why they are incorrect. Two of the primary arguments that have been used are
- By virtue of the second law of Thermodynamics, heat cannot be transferred from a colder to a warmer body, and
- Since solar energy is the basic source of all energy on Earth, if we do not change the amount of solar energy absorbed, we cannot change the effective radiating temperature of the Earth.
Both of the above statements are certainly true, but as we will show, the so-called “greenhouse theory” does not violate either of these two statements. (we use quotation marks around the words “greenhouse theory” to indicate that while this terminology has been generally adopted to explain the predicted warming with the addition of absorbing gases into the atmosphere, the actual process is quite a bit different from how a greenhouse heats).
With regards to the violation of the second law, what actually happens when absorbing gases are added to the atmosphere is that the cooling is slowed down. Equilibrium with the incoming absorbed sunlight is maintained by the emission of infrared radiation to space. When absorbing gases are added to the atmosphere, more of emitted radiation from the ground is absorbed by the atmosphere. This results in increased downward radiation toward the surface, so that the rate of escape of IR radiation to space is decreased, i.e., the rate of infrared cooling is decreased. This results in warming of the lower atmosphere and thus the second law is not violated. Thus, the warming is a result of decreased cooling rates.
Going to the second statement above, it is true that in equilibrium, if the amount of solar energy absorbed is not changed, then the amount of IR energy escaping out of the top of the atmosphere also cannot change. Therefore the effective radiating temperature of the atmosphere cannot change. But, the effective radiating temperature of the atmosphere is different from the vertical profile of temperature in the atmosphere. The effective radiating temperature is that T that will give the proper value of upward IR radiation at the top of the atmosphere such that it equals the solar radiation absorbed by the Earth-atmosphere system.
In other words, it is the temperature such that 4 pi x Sigma T4 equals pi Re2 Fso, where Re is the Earth’s radius, and Fso is the solar constant. Now, when we add more CO2, the absorption per unit distance increases, and this warms the atmosphere. But the increased absorption also means that less radiation from lower, warmer levels of the atmosphere can escape to space. Thus, more of the escaping IR radiation originates from higher, cooler levels of the atmosphere. Thus, the same effective radiating temperature can exist, but the atmospheric column has warmed.
These arguments, of course, do not take into account feedbacks which will kick in as soon as a warming (or cooling) begins.
The bottom line here is that when you add IR absorbing gases to the atmosphere, you slow down the loss of energy from the ground and the ground must warm up. The rest of the processes, including convection, conduction, feedbacks, etc. are too complicated to discuss here and are not completely understood anyway. But the radiational forcing due to the addition of greenhouse gases must result in a warming contribution to the atmosphere. By itself, this will not result in a change of the effective radiation temperature of the atmosphere, but it will result in changes in the vertical profile of temperature.
The so-called “greenhouse effect” is real. The question is how much will this effect be, and this is not a simple question. There are also questions being raised as to the very sign of some of the larger feedbacks to add to the confusion. Our purpose here was to merely point out that the addition of absorbing gases into the atmosphere must result in warming, contrary to some research currently circulating that says to the contrary.
For those that might still question this conclusion, consider taking away the atmosphere from the Earth, but change nothing else, i.e., keep the solar albedo the same (the lack of clouds would of course change this), and calculate the equilibrium temperature of the Earth’s surface. If you’ve done your arithmetic correctly, you should have come up with something like 255 K. But with the atmosphere, it is about 288 K, 33 degrees warmer. This is the greenhouse effect of the atmosphere.
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Morris Minor says:
Nonsense from start to finish. When you “look” at an object with a device that detects radiation, it has no way of detecting the radiation that said object is absorbing. It just detects the radiation that the object is emitting (or reflecting).
It is true that the net heat flow between the two bodies (where some would say the word “net” is redundant depending on how you define “heat”) has to take into account both the emission and the absorption. However, that does not mean that the Steffan-Boltzmann is some sort of convenient fiction. It is fact that the emission is occurring as described by that equation, and independent of that, absorption of radiation from other objects is also occurring.
kwik says:
Well, then either you had a teacher who was teaching you incorrect things or (more likely) you misunderstood or misremember what they told you.
Back radiation.
I think I see the confusion here among those that say back radiation doesn’t exist. I think they are actually saying net radiation has to be from warmer to colder, so they confuse back radiation with net radiation. Taking the IR radiation measurements near the surface as an example, you have upward and downward components, the downward one being what we mean by back radiation. Net radiation is the difference between these, and would most often be upwards. Upward radiation has a well defined spectrum, close to the black-body ground temperature spectrum. Downward IR radiation has a spectrum mostly determined by the GHGs in clear sky, or cloud temperatures below clouds. In the absence of GHGs (or clouds for that matter), you would basically see not much more than the cosmic background radiation, or perhaps small effects of dust in the air, but essentially a zero back radiation. In the current atmosphere, even clear skies have a few hundred W/m2 downward, canceling a large amount of the upwards black-body radiation from the surface. This is why the surface is 288 K, not 255 K.
Joel Shore says:
July 25, 2010 at 9:53 am
[–snip for brevity–] I guess you are another believer in the Second Law as magic, whereby a cooler object placed near a warmer object magically detects this fact and stops radiating any of the energy toward the warmer object.
The scientific community, by contrast, believes in the Second Law as a statement of statistical physics, whereby the colder object will always absorb more heat from the warmer object than the warmer object absorbs from the colder object. From this point of view, a colder object can indeed make a warmer object warmer than it would be in the absence of the colder object. [–snip rest–]
Your remark is an non sequitur.
I challenge you to prove —with instrumented evidence— that a cold object having been placed adjacent to a warmer object, will in fact cause the warmer object to become warmer than what it was prior to the placement of the cooler object.
You’ll be doing that, won’t you?
HankHenry says:
July 25, 2010 at 6:02 am
cba, I can appreciate ignoring internal temps but in the deep ocean you have a very cold region bounded above and below by warmer temps. Yes we want to disregard the earth’s internal heat but I’m not sure you have a very well defined notion of surface temperature if you disregard extensive cool areas. The earths temp on the continents at deep ocean depths is quite hot (see accounts of south African mines or deep boreholes). There has to be some process removing heat from the ocean and it has to be a large effect considering the extent of deep ocean cold.
=============
Hank,
if it’s not on the surface, it’s not part of the surface. We know less of the deep ocean than of the surface of Mars or the far side of the moon. It’s thought that the number of active subsea volcanos could number in the thousands or tens of thousands. One also must be careful in that the basic crust subsea is denser than continental crust as I recall. Water is a poor conductor of heat but being a liquid, convection and motion also take place.
I disagree that there’s necessarily a large heat removal from the ocean – at least compared to what is involved on the surface. There is a complex circulation going on that is not amenable to simplification for conceptual understanding. There is not a massive amount of heat transferring into the deep ocean. Nothing from the surface radiation goes anywhere close to the deep areas. Salt water is denser than than fresh and even though liquid h2o has a maximum density at a temperature above freezing, one is going to have very little heat transferring from the surface downwards. It’s actually the below average T h2o that does go down into the depths.
One of the big myths going on is the importance of the ocean contribution – “that hasn’t happened yet”. The problem with it is that because the heat transfer rate is low, it has practically no impact. The electrical analogy would be trying to supplant a 12 v, 12W flashlight (8 d-cells) using a 100 Amp-hour car battery through a 1 megohm resistor. While it’s easily measureable, there’s never going to be any practical contribution from the circuit going through that 1 megohm resistor. It will take a very long time (from a practical situation, the battery would probably self discharge at a faster rate). Same thing goes for that 6000K interior of the Earth. It’s as hot as the sun’s photosphere and it’s just a few miles away instead of almost 100 million miles away but it’s contribution is negligible.
Ferenc,
Do you have a reference to your new paper that isn’t behind a paywall? arXiv perhaps?
I’d like to read it but I can’t afford $30.
Dave Springer says:
July 25, 2010 at 8:33 am
“Back radiation” appears to be nonsense. When two bodies out of thermal equilbrium have a transfer path between them heat flows from the warmer to the colder (2nd law of thermodynamics). The farther out of equilibrium the faster the transfer. I suppose one could envisage back radiation as what causes the slowdown in heat flow the nearer to thermal equilibrium the bodies become but that doesn’t change the end result of the net heat flow going from warmer to colder.
Exactly it’s net heat and ‘back radiation’ is always present! Energy passes in both directions at all times.
899 says:
July 25, 2010 at 10:49 am
Joel Shore says:
July 25, 2010 at 9:53 am
[–snip for brevity–] I guess you are another believer in the Second Law as magic, whereby a cooler object placed near a warmer object magically detects this fact and stops radiating any of the energy toward the warmer object.
The scientific community, by contrast, believes in the Second Law as a statement of statistical physics, whereby the colder object will always absorb more heat from the warmer object than the warmer object absorbs from the colder object. From this point of view, a colder object can indeed make a warmer object warmer than it would be in the absence of the colder object. [–snip rest–]
Your remark is an non sequitur.
I challenge you to prove —with instrumented evidence— that a cold object having been placed adjacent to a warmer object, will in fact cause the warmer object to become warmer than what it was prior to the placement of the cooler object.
You’ll be doing that, won’t you?
Look up radiative shielding on thermocouples on Google you’ll find plenty of examples.
I would suggest you read a basic textbook on radiational heat transfer since your knowledge is sadly lacking.
The sun and Max Planck agree.
http://scienceofdoom.com/2010/06/01/the-sun-and-max-planck-agree/
http://scienceofdoom.com/2010/07/25/the-sun-and-max-planck-agree-part-two/
Dave Springer said:
“Put a heat lamp over a pan of water and see if the water temperature rises. I suspect it will”
Yep, If you introduce a heat source the water warms, evaporation increases.
” but I also suspect that the rate of heating will be vastly effected by the relative humidity of the air above the water”
Right again, as the humidity increases more energy will be returned to the water by molecules of H2O vapor returning to the surface, so this increased humidity will also slow evaporation.
“and also the rate of movement of the air over the water, i.e. place a fan blowing air across the water and see if that doesn’t go so far as to not just cancel the radiative heating but actually overpower it depending on the ambient humidity level.”
Yes, but if the fan was operating from the start the water surface would initially be cooler, the additional energy from the lamp when it’s introduced will still warm the water relative to this initial cooler state.
Andrew W says:
“Yes, but if the fan was operating from the start the water surface would initially be cooler, the additional energy from the lamp when it’s introduced will still warm the water relative to this initial cooler state.”
From the start of what ?
No fan heater however hot will warm a body of water. It warms only the topmost molecules that promptly evaporate drawing the latent heat of evaporation from water or air. The hotter the air the more of that energy will come from the air rather than the water but the main body of water will get no warmer.
Have you ever wondered why the heating element in a kettle is placed under the water ?
Stephen, what’s with the fan heater? No one has mentioned it before.
Andrew W says:
July 25, 2010 at 1:53 pm
Stephen, what’s with the fan heater? No one has mentioned it before.
It’s called cheating, cooling the surface of the water by constantly displacing the equilibrium at the surface by removing the water vapor thereby promoting more
evaporative cooling which has nothing to do with the radiant heat at all, something of a deus ex machina.
Let’s do it properly Stephen, still conditions with an equilibrated atmosphere above the surface, then what would happen?
Herman and Pielke claim “the greenhouse theory” does not violate the second law of thermodynamics. Gerlich and Tscheuschner claim this theory does violate the second law.
The question of which of the two claims is correct has a interesting answer. The answer is that both claims are correct! That contradictory claims are both correct violates the principle of logic called “non-contradiction.”
The violation of non-contradiction exposes the existence of a so-called “foundational error” in climatology. When such an error is found in a science, this finding is sufficient to invalidate the associated field of inquiry as a science. This field must be rebuilt on a foundation that lacks the error in order for the field to be re-established as a science.
Violation of non-contradiction invalidates a field of inquiry as a science because theories of this field lack the property called “falsifiability.” The falsifiability of its theories is the mark of a science.
That contradictory claims are correct in reference to the truth or falsity of “the greenhouse theory” results from ambiguity of reference by the word “heat” in climatology. In thermodynamics, the word “heat” references the energy that crosses a boundary; let this definition be labelled by the symbol “heat-t; “heat-t” is a mnemonic for “heat-thermodynamics.” Under the second law of thermodynamics, heat-t does not flow up a temperature gradient unless pumped.
Many climatologists use the word “heat” in reference to different concepts. This “heat” flows up a temperature gradient without being pumped. For these climatologists, it is the “net heat” that does not flow up a temperature gradient without being pumped.
The concept that is referenced by the latter use of the word “heat” can be identified with a bit of detective work. At an (x, y, z) space point in a radiation field, a number of different Poynting vectors reside. The radiative heat-t flow at this space point is the vector sum of these Poynting vectors.
The Poynting vectors can be divided into two groups. Let one group contain those Poynting vectors that are incident on a surface that contains the space point. In technical English the vector sum of the Poynting vectors in this group is called the “vector irradiance”; the magnitude of this vector is called the “irradiance.”
The Poynting vectors in the other group are reflected through the surface or they are transmitted or emitted through this surface. In technical English the vector sum of the Poynting vectors in this group is called the “vector radiosity”; the magnitude of this vector is called the “radiosity.”
By convention, the vector radiosity at a space point points away from this space point. The vector irradiance at a space point points toward this space point. It follows that the radiative heat flow at a space point is the vector difference of the vector radiosity and the vector irradiance.
For the many climatologists for which the word “heat” is not synonymous with the word “heat-t,” the phrase “heat flow” references either a vector radiosity or vector irradiance. If they wished, climatologists could eliminate this foundational error by agreement to make the word “heat” synonymous with “heat-t” and to use the phrase “vector irradiance” or “vector radiosity” in reference to the associated concepts rather than the phrase “heat flow.”
After a year’s worth of research, I’ve discovered three foundational errors in climatology. None have been corrected by climatologists. In each case, the presence of the error makes climatological theories non-falsifiable. Among the non-falsifiable theories are the “the greenhouse theory” and the IPCC climate models.
899 says:
July 25, 2010 at 10:49 am
“I challenge you to prove —with instrumented evidence— that a cold object having been placed adjacent to a warmer object, will in fact cause the warmer object to become warmer than what it was prior to the placement of the cooler object.”
Yes, with all the hundreds upon hundreds of millons of dollars the CAGW industry has received the last 20 years, thats the least we taxpayers can expect.
I too challenge you; Put a video on youtube.
-Two heating elements.
-Run currents through them so that each has stabilised on a certain temperature.
-One is stable at 400 deg celcius.
-One is stable at 300 deg celcius.
-Measure with a “Temp.Gun”.
-Put the 300 deg close to the 400 deg.
-Measure.
-Does the temperature increase?
Will be interesting to see the result.
Stephen Wilde says:
The problem is that when you set yourself up as judge and jury on the rebuttal, that sort of biases the rest of whether you consider a reasonable rebuttal to have been given. In fact, in my view, I have rebutted your argument many times, most recently here http://wattsupwiththat.com/2010/07/23/quantifying-the-greenhouse-effect/#comment-439141
Terry Oldberg: Just when I thought that the claims being made by the posters in this thread could not get any more bizarrre, you prove me wrong! My hat is off to you!
The IDEA, The NOTION, The BELIEF, The MECHANISM…. the fools today speak our future — or our we fools?
kwik quotes 899 as follows:
“I challenge you to prove —with instrumented evidence— that a cold object having been placed adjacent to a warmer object, will in fact cause the warmer object to become warmer than what it was prior to the placement of the cooler object.”
Roy Spencer argues that this works in a vacuum; that is, it works if convection and conduction are not operative. (Why he is willing to apply this reasoning to the atmosphere beats me.) The article is at the Climatechangefraud dot com website.
In the discussion:
899 says:
July 25, 2010 at 10:49 am
Joel Shore says:
July 25, 2010 at 9:53 am
“[–snip for brevity–] I guess you are another believer in the Second Law as magic, whereby a cooler object placed near a warmer object magically detects this fact and stops radiating any of the energy toward the warmer object.
“The scientific community, by contrast, believes in the Second Law as a statement of statistical physics, whereby the colder object will always absorb more heat from the warmer object than the warmer object absorbs from the colder object. From this point of view, a colder object can indeed make a warmer object warmer than it would be in the absence of the colder object. [–snip rest–]”
899’s response was: “Your remark is an non sequitur.
“I challenge you to prove —with instrumented evidence— that a cold object having been placed adjacent to a warmer object, will in fact cause the warmer object to become warmer than what it was prior to the placement of the cooler object.
You’ll be doing that, won’t you?”
On balance, I agree with 899; but I believe Joel and 899 are saying slightly different things.
Joel claims: “…a colder object can indeed make a warmer object warmer than it would be in the absence of the colder object.”
899 wants Joel to prove “that a cold object having been placed adjacent to a warmer object, will in fact cause the warmer object to become warmer than what it was prior to the placement of the cooler object.“.
899’s statement addresses an increase in the temperature of the warmer object relative to its initial temperature–a clear and unambiguous statement. Joel’s statement, I believe, addresses a comparison as a function of time of the warmer object’s temperature with and without the insertion of an adjacent cooler object.
Can’t both statements be true? For example, suppose (a) in both the presence and absence of the cooler object, the warmer object’s temperature decreases, but (b) the rate of temperature decrease, which is positive, is smaller in the presence of the cooler object than in the absence of the cooler object. 899 would be correct because the temperature of the warmer object never exceeds its original temperature. Joel would be correct in the sense that at any given time after the introduction of the cooler object, the temperature of the warmer object is higher than it would have been if the cooler object had never been introduced–not higher than its original temperature, just higher as a function of time than it would be if the cooler object was never introduced.
Provided there are no energy sources internal or external to any body (e.g., no chemical energy is converted to heat, no nuclear energy is converted to heat, no potential energy is converted to heat, no kinetic energy is converted to heat, no work is done, etc.), I believe 899’s statement is more robust than Joel’s statement. By robust I mean when no thermal energy is being generated by conversion of other types of energy, 899’s statement is true under all conditions; whereas Joel’s statement is not.
For example, consider two concentric, unequal-radius, spherical, “infinitely-thin”, black-body-surface, spherical shells in a vacuum where the inner shell is everywhere at temperature TI (Kelvins), the outer shell is everywhere at temperature TO (TI^4)*RI^2/(RI^2 + RO^2), the rate of energy radiated by the outer shell to space (i.e., external to the outer shell) will exceed the rate of energy transfered from the inner shell to the outer shell and the temperature of the outer shell will decrease. However, when TO^4 < (TI^4)*RI^2/(RI^2 + RO^2), the rate of energy radiated by the outer shell to space (i.e., external to the outer shell) will be smaller than the rate of energy transfered from the inner shell to the outer shell and the temperature of the outer shell will increase. Eventually the temperature of the inner shell will drop so that the rate of energy radiated to space by the outer shell will exceed the rate of energy received from the inner shell and the temperature of both shells will drop. However, under no circumstances will the temperature of the inner shell increase.
Now let's insert an object at temperature T2TO, the initial net rate at which energy leaves the inner shell will be decreased relative to the no object case. This is because a part of the background “seen” by the inner shell is now at a higher temperature than TO, which results in a relative decrease in the rate of inner (warmer) shell energy loss. However, if T2<TO, the initial rate at which energy leaves the inner shell will be increased relative to the no object case. This is because a part of the background seen by the inner shell is now at a lower temperature than TO, which results in a relative increase in the rate of inner (warmer) shell energy loss. Thus in one case [the inserted cooler object is warmer than the "background" as seen by the inner (warmer) shell], the rate of inner shell energy loss is decreased. However in the other case [the inserted object is colder than the "background" seen by the inner shell], the rate of inner shell energy loss is increased. Thus Joel's statement about the relative temperature as a function of time of the inner shell (warmer object) is correct only when the temperature of the inserted "cooler object" is less than the "inner shell background temperature" it replaces; while 899's statement is universally true.
I still have a question which I have asked before, but people decided to nitpick over the illustration I gave instead.
MY QUESTION IS: While CO2 blocks radiation from escaping from the atmosphere, thereby producing a greenhouse forcing, to what degree does CO2 block radiation from entering the atmosphere, thereby producing a negative feedback? Has that negative impact (if it exists) been included in the calculations?
Reference my immediately previous post, the use of the “less than” symbol seems to bolix up the text. I am going to replace all “less than” and “greater than” symbols with, respectively, .LT. and .GT. and repost my comment.
In the discussion:
899 says:
July 25, 2010 at 10:49 am
Joel Shore says:
July 25, 2010 at 9:53 am
“[–snip for brevity–] I guess you are another believer in the Second Law as magic, whereby a cooler object placed near a warmer object magically detects this fact and stops radiating any of the energy toward the warmer object.
“The scientific community, by contrast, believes in the Second Law as a statement of statistical physics, whereby the colder object will always absorb more heat from the warmer object than the warmer object absorbs from the colder object. From this point of view, a colder object can indeed make a warmer object warmer than it would be in the absence of the colder object. [–snip rest–]”
899’s response was: “Your remark is an non sequitur.
“I challenge you to prove —with instrumented evidence— that a cold object having been placed adjacent to a warmer object, will in fact cause the warmer object to become warmer than what it was prior to the placement of the cooler object.
You’ll be doing that, won’t you?”
On balance, I agree with 899; but I believe Joel and 899 are saying slightly different things.
Joel claims: “…a colder object can indeed make a warmer object warmer than it would be in the absence of the colder object.”
899 wants Joel to prove “that a cold object having been placed adjacent to a warmer object, will in fact cause the warmer object to become warmer than what it was prior to the placement of the cooler object.“.
899’s statement addresses an increase in the temperature of the warmer object relative to its initial temperature–a clear and unambiguous statement. Joel’s statement, I believe, addresses a comparison as a function of time of the warmer object’s temperature with and without the insertion of an adjacent cooler object.
Can’t both statements be true? For example, suppose (a) in both the presence and absence of the cooler object, the warmer object’s temperature decreases, but (b) the rate of temperature decrease, which is positive, is smaller in the presence of the cooler object than in the absence of the cooler object. 899 would be correct because the temperature of the warmer object never exceeds its original temperature. Joel would be correct in the sense that at any given time after the introduction of the cooler object, the temperature of the warmer object is higher than it would have been if the cooler object had never been introduced–not higher than its original temperature, just higher as a function of time than it would be if the cooler object was never introduced.
Provided there are no energy sources internal or external to any body (e.g., no chemical energy is converted to heat, no nuclear energy is converted to heat, no potential energy is converted to heat, no kinetic energy is converted to heat, no work is done, etc.), I believe 899’s statement is more robust than Joel’s statement. By robust I mean when no thermal energy is being generated by conversion of other types of energy, 899’s statement is true under all conditions; whereas Joel’s statement is not.
For example, consider two concentric, unequal-radius, spherical, “infinitely-thin”, black-body-surface, spherical shells in a vacuum where the inner shell is everywhere at temperature TI (Kelvins), the outer shell is everywhere at temperature TO .LT. TI (Kelvins), and the temperature of the space external to the outer shell is 0 Kelvins. The rate of energy transfer between the shells (energy flow from the inner to outer shell) is 4*pi*sigma*(RI^2)*(TI^4 – TO^4), where RI is the radius of the inner shell, and sigma is the Stefan-Boltzmann constant. Since we have no internal energy sources, as energy leaves the inner shell, the temperature of the inner shell will decrease. The rate of temperature decrease will depend in part on the specific heat of the inner shell. Because external to the outer shell we have assumed a temperature of 0, the outer shell will radiate energy external to itself at the rate 4*pi*sigma*(RO^2)*(TO^4),
As long as TO^4 .GT. (TI^4)*RI^2/(RI^2 + RO^2), the rate of energy radiated by the outer shell to space (i.e., external to the outer shell) will exceed the rate of energy transfered from the inner shell to the outer shell and the temperature of the outer shell will decrease. However, when TO^4 .LT. (TI^4)*RI^2/(RI^2 + RO^2), the rate of energy radiated by the outer shell to space (i.e., external to the outer shell) will be smaller than the rate of energy transfered from the inner shell to the outer shell and the temperature of the outer shell will increase. Eventually the temperature of the inner shell will drop so that the rate of energy radiated to space by the outer shell will exceed the rate of energy received from the inner shell and the temperature of both shells will drop. However, under no circumstances will the temperature of the inner shell increase.
Now let’s insert an object at temperature T2 .LT. T1 between the two shells. If T2 .GT. TO, the initial net rate at which energy leaves the inner shell will be decreased relative to the no object case. This is because a part of the background “seen” by the inner shell is now at a higher temperature than TO, which results in a relative decrease in the rate of inner (warmer) shell energy loss. However, if T2 .LT. TO, the initial rate at which energy leaves the inner shell will be increased relative to the no object case. This is because a part of the background seen by the inner shell is now at a lower temperature than TO, which results in a relative increase in the rate of inner (warmer) shell energy loss. Thus in one case [the inserted cooler object is warmer than the “background” as seen by the inner (warmer) shell], the rate of inner shell energy loss is decreased. However in the other case [the inserted object is colder than the “background” seen by the inner shell], the rate of inner shell energy loss is increased. Thus Joel’s statement about the relative temperature as a function of time of the inner shell (warmer object) is correct only when the temperature of the inserted “cooler object” is less than the “inner shell background temperature” it replaces; while 899’s statement is universally true.
kwik says:
July 25, 2010 at 4:02 pm
899 says:
July 25, 2010 at 10:49 am
“I challenge you to prove —with instrumented evidence— that a cold object having been placed adjacent to a warmer object, will in fact cause the warmer object to become warmer than what it was prior to the placement of the cooler object.”
Yes, with all the hundreds upon hundreds of millons of dollars the CAGW industry has received the last 20 years, thats the least we taxpayers can expect.
I too challenge you; Put a video on youtube.
-Two heating elements.
-Run currents through them so that each has stabilised on a certain temperature.
-One is stable at 400 deg celcius.
-One is stable at 300 deg celcius.
-Measure with a “Temp.Gun”.
-Put the 300 deg close to the 400 deg.
-Measure.
-Does the temperature increase?
Will be interesting to see the result.
Smoke dope much?
[1] Placing 300º hot plate next to a 400º hot plate does NOT cause the 400º to get warmer; the instrument reading is summing the values.
[2] Constraining the area around either hot plate will cause an APPARENT rise in temperature, but NOT an actual rise. What’s being measured is the cumulative.
So, before you start blowing snot in my direction, you ought get your own crap in one sack!!
what we have is a warmer object being made warmer (only in the sense of reduced power transfer) by a cooler object which has replaced a really cold object. Space is radiating back at 3K if one puts in an atmosphere with ghgs, it’s going to radiate back at perhaps 220k. What has happened is the net radiation from our surface at 288k is no longer radiaating a full 391 w/m^2 away (assuming 3k radiates 0 w/m^2) but now, crudely put, the atmosphere is radiating back at 133w/m^2 (assuming for this example that it is a bb with emissivity of 1 rather than a value much lower than 1). Now the surface only sluffing off 391-133 = 258 w/m^2. If our example were in radiative equilibrium sluffing off 391 w/m^2 – that means we were receiving 391 w/m^2 and now adding this atmosphere has reduced that to 258 w/m^2 so it’s going to be out of radiative equilibrium until once again, we sluff off the amount of power received. The temperature must rise, not because we are being heated by a colder body but because we are no longer shedding as much power as we were when we were shedding to the 3K microwave background of space.
Andrew W
“Andrew W says:
July 25, 2010 at 1:53 pm
Stephen, what’s with the fan heater? No one has mentioned it before.”
You mentioned a lamp plus a fan. That is a fan heater.
Phil said:
“Let’s do it properly Stephen, still conditions with an equilibrated atmosphere above the surface, then what would happen?”
Even without a fan the latent heat of evaporation would be taken equally from air and water if the temperatures were equilibrated. There would be no warming of the main body of the water because all the IR is used to generate increased evaporation due to it failing to get past the evaporative layer.
In the real world under an open sky. there is always enough air movement plus low enough humidity on average globally for the oceans never to gain energy from an IR source. In fact globally more IR causes more net cooling for that very reason.
Joel says:
“The problem is that when you set yourself up as judge and jury on the rebuttal, that sort of biases the rest of whether you consider a reasonable rebuttal to have been given.”
Since I am seeking truth I am not biased against a reasonable rebuttal. Yours is not such because it misses the point.
This is relevant from Roy Spencer’s blog:
“Stephen Wilde says:
July 25, 2010 at 11:47 AM
I think I can make this very simple.
A cooler object near a warmer object will slow the rate of cooling of the warmer object because of the exchange of energy to and fro between the two objects before that energy departs the combined system.
If there is a constant energy input throughout then the slowing down of the rate of cooling will cause the warmer object to settle at a higher equilibrium temperature than would otherwise have been the case.
Thus the presence of the cooler object does indeed result in the warmer object becoming warmer than it otherwise would have done.
That is the essence of the greenhouse effect which is a concept I have always accepted despite the misleading nomenclature.
Any sceptical viewpoints that rely on denying those simple facts must be rejected because they weaken the sceptical cause.”
To which there was this comment:
“Colin Henderson says:
July 25, 2010 at 1:54 PM
I see your point, the cold body acts as a secondary heat source increasing the amount of energy going into the warm bodys and increasing the warm body temperature equilibrium. The warm body, now being at a higher temperature increases the radiation falling on the cold body, which in turn radiates more energy to the warm body, further warming it. I just can’t seem to get my head around where this loop ends, it seems like a perpetual motion machine and/or an M.C. Escher drawing.”
My reply being:
“Colin,
There is no ‘loop’.
There is only a slowing of the rate of cooling. No energy is being added to either of the two bodies.
With a constant source of energy from an outside source one only needs to slow the rate of cooling to achieve a higher equilibrium temperature.”
Chad Woodburn, I think Science Of Doom answers your question in a couple of recent posts, basically the amount of longer wave IR received from the sun at the top of the atmosphere is insignificant compared to that emitted by atmospheric GH gases.
Reed Coray, Joel Shore was I think talking about two objects held at a constant temperature by internal heat sources, by bringing the two objects close together each receives additional energy from the other, so the temperature of both objects rises.