Guest Post by Willis Eschenbach
Short answer? Of course not, that would violate the Second Law of Thermodynamics … BUT it can leave the hot object warmer than it would be if the cold object weren’t there. Let me explain why this is so.
Let me start by introducing the ideas of individual flows and net flows. Suppose I owe you twenty-five dollars. I run into you, but all I have is a hundred dollar bill. You say no problem, you have seventy-five in cash. I give you the hundred, you give me the seventy-five, and the debt is paid.
Now, there are two equally valid ways to describe that transaction. One way looks at both of the individual flows, and the other way just looks at the net flow. Here they are:
Figure 1. Net flows and individual flows. The individual flows are from me to you, $100, and from you to me, $75. The net flow is from me to you, $25.
What does this have to do with cold and warm objects? It points out a very important distinction, that of the difference between individual flows of energy and the net flow of energy, and it relates to the definition of heat.
Looking at Figure 1, instead of exchanging dollars, think of it as two bodies exchanging energy by means of radiation. This is what happens in the world around us all the time. Every solid object gives off its own individual flow of thermal radiation, just as in the upper half of Figure 1. We constantly radiate energy that is then being absorbed by everything around us, and in turn, we constantly absorb energy that is being radiated by the individual objects around us.
“Heat”, on the other hand, is not those individual flows of energy. Heat is the net flow of energy, as represented in the bottom half of Figure 1. Specifically, a heat flux is the net flow of energy that occurs spontaneously as a result of temperature differences.
Now, the Second Law of Thermodynamics is only about net flows. It states that the net flow of thermal energy which we call “heat” goes from hot to cold each and every time without exception. However, the Second Law says nothing about the individual flows of energy, only the net flow. Heat can’t flow from cold to hot, but radiated energy absolutely can.
When an object emits radiation, that radiation goes on until it hits something that absorbs it, whereupon it is converted to thermal energy. The individual temperatures of the emitting and absorbing objects are not significant because these are individual energy flows, and not the net energy flow called “heat”. So there is no violation of the Second Law.
Here’s the thing that keeps it all in balance. If I can see you, you can see me, so there are no one-way energy flows.
Which means that if I am absorbing radiation from you, then you are absorbing radiation from me. If you are warmer than me, then the net flow of energy will always be from you to me. But that says nothing about the individual flows of energy. Those individual flows only have to do with the temperature of the object that is radiating.
So how do we calculate this net energy flow that we call “heat”? Simple. Gains minus losses. Energy is conserved, which means we can add and subtract flows of energy in exactly the same way that we can add and subtract flows of dollars. So to figure out the net flow of energy, it’s the same as in Figure 1. It’s the larger flow minus the smaller flow.
With all of that as prologue, let me return to the question that involves thermal radiation. Can a cold object leave a warm object warmer than it would be without the cold object?
While the answer is generally no, it can do so in the special case when the cold object is hiding an even colder object from view.
For example, if a person walks between you and a small campfire, they hide the fire from you. As soon as the fire is hidden, you can feel the immediate loss of the radiated energy. At that moment, you are no longer absorbing the radiated energy of the fire. Instead, you are absorbing the radiated energy of the person between you and the fire.
And the same thing can happen with a cold object. If there is a block of wood between you and a block of ice, if you remove the wood, you’ll get colder because you will be absorbing less radiation from the ice than you were from the wood. You no longer have the wood to shield you from the ice.
Why is all of this important? Let me offer up another graphic, which shows a simple global energy budget.
Figure 2. Greatly simplified global energy budget, patterned after the Kiehl/Trenberth budget. Unlike the Kiehl/Trenberth budget, this one is balanced, with the same amount of energy entering and leaving the surface and each of the atmospheric layers. Note that the arrows show ENERGY flows and not HEAT flows.
These ideas of individual flows, net flows, and being shielded from radiation are important because people keep repeating over and over that a cold atmosphere cannot warm the earth … and they are right. The temperature and the radiation are related to each other by the Stefan-Boltzmann equation. When we apply the S-B equation to the 321 W/m2 of downwelling “back radiation” shown in the graphic above, it tells us that the effective radiating level is somewhere around freezing, much colder than the surface.
BUT a cold atmosphere can leave the earth warmer than it would be without the atmosphere because it is hiding something even colder from view, the cosmic microwave background radiation that is only a paltry 3 W/m2 …
And as a result, with the cold atmosphere shielding us from the nearly infinite heat sink of outer space, the earth ends up much warmer than it would be without the cold atmosphere.
To summarize …
• Heat cannot flow from cold to hot, but radiated energy sure can.
• A cold atmosphere radiates about 300-plus W/m2 of downwelling radiation measured at the surface. This 300-plus W/m2 of radiated energy leaves the surface warmer than it would be if we were exposed to the 3 W/m2 of outer space.
My best regards to all,
w.
My Usual Request: When you comment, please QUOTE THE EXACT WORDS THAT YOU ARE DISCUSSING, so that we can all understand the nature of your objections.
My Second Request: Please keep it civil. Speculation about the other person’s motives and cranial horsepower are greatly discouraged.
Further Reading: My post entitled “The Steel Greenhouse” looks at how the poorly-named “greenhouse effect” work, based on the principles discussed above.
Math Notes: There’s an excellent online calculator for net energy flow between two radiating bodies here. It also has the general equation used by the calculator, viz:
with the following variables:
and Q-dot (left-hand side of the equation) being the net flow.
Now, when the first object is totally enclosed by the second object, then area A2 is set to a very large number (I used a million) and the view factor F12 is set to 1. This is the condition of the earth completely surrounded by the atmosphere. For the general case, I’ve set area A1 to 1 square metre. Finally, I’ve made the usual simplifying assumption that thermal IR emissivity is 1.0 for the surface and the atmosphere. The emissivity values are greater than 0.9 in both cases, so the error is small. With those usual assumptions, the equation above simplifies as follows, courtesy of Mathematica:
But sigma T ^ 4 is simply the Stefan-Boltzmann radiation for the given temperature. That is why, in the energy budget above, we can simply add and subtract the energy flows to produce the budget and check to see if it is balanced.
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Facepalm facepalm facepalm. It hurts too much to read the whole of Willis’s self confusion on this subject.
Just take the energy budget diagram near the end. Look at the numbers on the left side versus the right side. Compare to the money example. Is the “net” flow from the earth to the atmosphere or from the atmosphere to earth? Did the Earth end up with more cash or less cash? Did the atmosphere give the earth change from $100 or did it give more cash back than was given to it?
169 from the sun into the earth where the hell do the right side numbers come from if you are not advocating cold heating hot?
There is NOTHING in physics that says the energy given off from a cooler object must be absorbed by a warmer object. That energy is NEVER added to the warmer object. The energy from an ice cube is not added to your total energy if you stand next to it, pick it up or put it in a Willis pseudoscience post. Your energy output will remain the same. It won’t jump from 169 to 392 like in the embarrassing energy budget diagram.
To raise the average surface temperature to what we observe you need something else. You can raise temperature by transferring heat from hot to cold OR you can introduce Work into your system.
The greenhouse effect does neither, so it is wrong.,
There is absolutely no difference between “NET flows from hot to cold” to “heat flows from hot to cold” the word “net” is superfluous and simply a tool of confusion. The instant that the energy from the hotter object increases in any thought experiment with a cooler one, the “net” flow is no longer from hot to cold, is it? So you are proposing a cooler object increasing the temperature of a warmer one.
“The instant that the energy from the hotter object increases in any thought experiment with a cooler one,”
Still confusion…
The energy of the hotter object is not increased!!
It is just decreasing more SLOWLY.
At no point does the energy/temp of the hotter object go UP.
Just goes down more SLOWLY.
” So you are proposing a cooler object increasing the temperature of a warmer one.”
NO NO and a zillion NOES.
“The greenhouse effect does neither, so it is wrong.,”
Then please explain why the Earth, when considering the energy it absorbs from the Sun is 33C warmer than it should be.
Why when viewed from space it does (255K).
Yet we live at 288K.
Toneb. The Earth is not 33C warmer than it should be. The calculation to derive 33C is based on modelling a flat Earth with no day and night and with the average energy received from the sun divided by four because the cross-sectional area of the earth is one quarter of the surface area. With those ridiculous assumptions you get the false result of 33C.
Phillip:
Sorry but it is. Satellites measure Earth’s temp at 255K
Phillip Bratby: “Toneb. The Earth is not 33C warmer than it should be”
Toneb: “Sorry but it is. Satellites measure Earth’s temp at 255K”
Tony: Exactly. The Earth is not 33 C warmer than it should be. Thanks Toneb.
“The energy from the hotter object is not increased. It is just decreasing more slowly”.
NO!!!!!
Look at the NUMBERS on the energy budget diagram. The sun (on that diagram) warms the surface of the earth to a value of 169W/m2. The atmosphere INCREASES that amount to 392W/m2. It has not cooled. It has WARMED.
The values on the left are what the sun provides. The values on the right are trying to explain (through bad science) what is observed.
The mechanism described CANNOT BE! Cold doesn’t INCREASE the temperature of something hotter! You need WORK to do that.
Gravity provides that work, not recycling of energy against the well established direction of heat flow.
You cannot raise the temperature of an object by “cooling it more slowly”. You can cool to a different end temperature, but that is not the same as cooling to a higher temperature than what you started with. The compete jumbled up word salad that the greenhouse effect acolytes use, is what causes the idiocracy. You can’t heat the earth up to a higher temperature than that which the sun is capable of heating it. Not without additional work.
“Tony: Exactly. The Earth is not 33 C warmer than it should be. Thanks Toneb.”
Earth absorbs solar energy such that it radiates at 255K
It does, as seen from space.
On the surface it is 288K (as an average).
33K warmer.
The GHE.
Let’s try putting my reply in the right place.
Toneb, what on Earth makes you think the calculated 255 K temperature should apply to the Earth’s surface, and not the Earth as a whole (which you agree is observed to be 255 K)?
“Toneb, what on Earth makes you think the calculated 255 K temperature should apply to the Earth’s surface, and not the Earth as a whole (which you agree is observed to be 255 K)?”
It does apply to the Earth as a whole (as satellites see the “whole Earth” while they measure an irradiance of 225K.
But actually the max radiation is being emitted at ~8km – the level the GHE has raise the effective radiance level to (on average -18C there).
“You cannot raise the temperature of an object by “cooling it more slowly”. You can cool to a different end temperature, but that is not the same as cooling to a higher temperature than what you started with. ”
You are, I think, fixated on the 288K being hotter than the 255K as though the GHE has heated the Earth (provided extra energy). It is an insulation effect, a slowing of emitted LWIR while Solar SW is still incoming (nano/micro seconds worth though it might be). The excess being mostly being stored and later (in the case of oceans – hence the thermal inertia) heating the atmosphere.
All the while the Earth is radiating. Cooling in the absence of the Sun. The GHE doesn’t (instantaneously) heat anything.
Which is hotter the surface or the atmosphere above (most generally)?
There is (nearly – some exceptions in WAA, warm air advection) always more energy being radiated from the Earth’s surface than any GHE can overcome.
It is not “new” energy. It is that that was first emitted from the surface (mainly).
The 33K higher temp has not been “switched on” – it is the result of the GHE slowed energy being stored in the oceans.
It cannot be “switched on” in the sense of switching on 33K.
An analogy:
Get into bed under a very high tog duvet.
You are going to feel warmer than a thinner one, yes?
Quite possibly you will get hot and start to sweat, yes?
Is the high tog duvet heating you?
Is it electrically powered?
You are still radiating heat (incoming solar SW) yet the duvet slows your cooling (GHE). You get hotter as there is an imbalance.
Additionally will the temp on the top of the duvet be hotter or colder?
GHE theory observed as stratospheric cooling.
To make the blanket analogy more apt you need to raise or lower the height and therefore temperature of the blanket as it moves up or down along the lapse rate slope.
Thus the presence of radiation to space from the blanket would weaken the vigour of convection beneath it and lower the blanket to a lower warmer height whereupon the blanket would radiate faster to space INSTEAD of warming the surface beneath.
The same applies to the so called steel shell concept.
The behaviour of gases as opposed to solids is quite different to the behaviour of solids such as steel or blankets.
You have to take account of convection and the lapse rate slope which are determined primarily by uneven conduction from the surface to ALL atmospheric gases.
— Toneb
November 25, 2017 at 2:15 am
Phillip:
Sorry but it is. Satellites measure Earth’s temp at 255K–
Excluding interior of earth, the warmest place on Earth is the surface.
The surface is where the sunlight is absorbed.
The satellites are obviously measuring the surface incorrectly if
they indicate the surface [which is average temperature of about
15 C [288 K] is 255 K.
Of course earth radiates 240 watts per square, and if earth was
a blackbody that would be 255 K at it’s surface where it’s absorbs
the sun’s energy. Earth of course reflects about 30% of sunlight-
anything reflecting 30% of sunlight is not a blackbody.
Blackbodies also radiate the most amount energy at a given temperature.
The earth surface has water evaporating and heat being loss due convection heat transfer
to the atmophere. Or if blackbody were losing heat by evaporation and convection heat
loss, it couldn’t radiate the most amount energy of it’s temperature. Or because
it doesn’t radiate the most at given temperature- it’s not a blackbody.
Or it would have to be in a vacuum for blackbody to be a blackbody.
You’re playing (er, comparing) Trenberth’s flat earth average cartoon with actual measured global satellite measurements? And just “how” did your source convert spherical measurements to a flat earth average square meter value for absorbed energy, reflected energy, and measured energy at the satellite altitude?
I speculate that the only reason the word “net” got included in this was because they needed it to catch all the little balls (aka photons).
So Toneb, your answer is that basically no matter what, the GHE is responsible. A temperature of 255 K (effective temperature) is calculated, you at first assume that should apply to the surface, therefore the 33 K difference is due to the GHE. When challenged on that, you switch to saying it’s because the GHE has raised the effective radiating level. No matter what, this non-existent difference has to be explained by a non-existent phenomenon. The conclusion is arrived at first – there is a GHE. Then the circumstances can be adapted to fit this conclusion. So there is no need to accept the premises unless you already accept the conclusion.
“So Toneb, your answer is that basically no matter what, the GHE is responsible. ”
For the +33K?
Yes.
Fundamentally because of the non-condensing GHG’s.
Without them than WV would comdense out as snow.
It is what the science tells us.
Do you have any that shows it isn’t?
https://pubs.giss.nasa.gov/docs/2010/2010_Lacis_la09300d.pdf
https://www.giss.nasa.gov/research/briefs/schmidt_05/
“The size of the greenhouse effect is often estimated as being the difference between the actual global surface temperature and the temperature the planet would be without any atmospheric absorption, but with exactly the same planetary albedo, around 33°C. This is more of a “thought experiment” than an observable state, but it is a useful baseline. Another way of quantifying the effect is to look at the difference between the infrared radiation emitted at the surface of the Earth, and the amount that is emitted to space at the top of the atmosphere. In the absence of the greenhouse effect, this would be zero (in other words, no difference). In actuality the surface emits about 150 Watts per square meter (W/m2) more than goes out to space.”
“The satellites are obviously measuring the surface incorrectly if
they indicate the surface [which is average temperature of about
15 C [288 K] is 255 K.”
The classic “with one bound he was free” answer.
Sorry but that level of, err, gainsaying, is beyond response – but ……
So they are measuring the temp of Venus “incorrectly” as well?.
Well yes of course!
How can a satellite measure the temp of Earth as being higher than the energy it receives from the Sun can provide?
What goes in comes out …..
However the GHE CAN keep it in via an ‘insulation’ effect.
Hidden from the view of the satellite.
What the planet cannot do is emit MORE than it receives.
Which is what you are saying it does.
Venus has an effective temp of 220K
Yet its GHE adds 510K at the surface to take it to 730K.
It is measured from space at 220 as that is what the SUN warms it to (in>>out).
The extra 510 has built up over millenia because of it’s CO2 atmosphere as it tries to get out via T^4.
This again reveals a fundamental misunderstanding of the nature of the GHE.
https://atmos.washington.edu/2002Q4/211/notes_greenhouse.html
I’m just pointing out that your logic is circular. Not making any point about why the atmosphere is warmer at the bottom than the top. You originally started out by saying:
“Then please explain why the Earth, when considering the energy it absorbs from the Sun is 33C warmer than it should be.
Why when viewed from space it does (255K).
Yet we live at 288K“
and I’m telling you that a theory that the surface is warmer than the effective temperature because of a GHE is not evidenced by the observation that the surface is warmer than the effective temperature. All that is demonstrated is that the surface is warmer than the effective temperature. But you wrote your comment as if this very observation alone was sufficient to provide evidence that the GHE was the cause.
You have received a comment further down about another possible cause.
Toneb,
The blanket analogy:
That blanket must be more of an afgan, crocheted with open holes in it, rather than a “high tog”. Only about 4% of that blanket can absorb your body heat and “return” it to you. You must also rotate beneath the blanket steadily, and place a blowing air fan under it with you.
Now how warm do you get ? Warm enough to sweat? Does the temperature of your skin even increase?
actually Willis knows exactly what he is saying and there is an article here that perfectly serves as an example of what he explains:
https://wattsupwiththat.com/climate-fail-files/gore-and-bill-nye-fail-at-doing-a-simple-co2-experiment/
think in it as the jar is the atmosphere and the infrared light is the sun.
Seems strange no one has mentioned the effect of gravity on the atmosphere and the resulting adiabatic lapse rate.
“There is NOTHING in physics that says the energy given off from a cooler object must be absorbed by a warmer object. That energy is NEVER added to the warmer object.”
And here we have the “sentient photon” myth.
Tell me, how does a photon emitted from a colder object know that it cannot be absorbed by the hotter object?
“The greenhouse effect does neither, so it is wrong.”
The D-K syndrome rages in some.
You are.
It doesn’t need to “know”. Photons from warmer objects have a different frequency and wavelength to photons from cooler objects. Nothing magical about it.
https://en.m.wikipedia.org/wiki/Photon_energy
Both object absorb/emit LWIR in the same narrow frequency band.
They are not different in that sense.
A thermalisation via atomic vibrational modes occurs.
Else Pyrometers would not work….
“Infrared radiation can have a wavelength of a fraction of a micron up to several hundred microns. Infrared thermometers measure infrared with a wavelength of between 4 and 14 microns. As it is the surface of an object that emits infrared, an infrared thermometer will not measure its internal (core) temperature.”
You’ve written some words. I’m not sure to what end, or who you were responding to, but OK.
How does the energy from a block of ice “know” not to make you warmer?
It doesn’t know squat. It just obeys the laws of physics, as does everything in the universe. You can argue over the why of it as much as you like and come up with whatever theory best fits. As long as you make your theory fit the observation and not the other way around.
So cold doesn’t transfer heat to hot. That is the UNIVERSAL observation. Whatever the theories about what photons are do or “know” needs to fit inside this basic fact.
Atoms and molecules can only absorb photons with certain discreet energy levels.
The incoming photon must be able to boost an atom or molecule into a higher energy state, otherwise it will just keep going.
Photons are not little billiard balls.
According to the theory of relativity, as an object approaches the speed of light, time slows down for that object.
At the speed of light, time would stop.
Photons are going the speed of light.
Does time stop for them?
Are they emitted at the same instant, from the perspective of the photon, as they reach their destination?
Could this explain some of the mysterious behavior we know they exhibit?
If they cannot be absorbed, could it be they are never emitted?
Also, photons are not simple particles…they behave like waves as well.
We know they have a wavelength…but do they also have breadth?
Are they getting wider in the direction of travel, perhaps?
We know photons can become entangled, exhibiting action at a distance.
And other stuff no one really understands.
because we do not have the proper way of thinking about them.
Or there would be no mysteries.
So trying to understand them in some intuitive mechanical way is never going to accurately describe their behavior properly.
“It doesn’t need to “know”. Photons from warmer objects have a different frequency and wavelength to photons from cooler objects. Nothing magical about it.”
The average frequency differs (for blackbody radiation) but to determine the temperature of the emitting object from a single photon does require magic according to present-day physics.
I have a photon with a wavelength of, say, 1.697 micron, will you please tell me the temperature of the emitter?
Toneb
November 25, 2017 at 1:28 am
“There is NOTHING in physics that says the energy given off from a cooler object must be absorbed by a warmer object. That energy is NEVER added to the warmer object.”
And here we have the “sentient photon” myth.
Tell me, how does a photon emitted from a colder object know that it cannot be absorbed by the hotter object?
Anything radiating heat is cooling, cold can’t cool to something hot.
“The average frequency differs (for blackbody radiation) but to determine the temperature of the emitting object from a single photon does require magic according to present-day physics“
Thankfully there is no requirement for the photon to do so.
“The D-K syndrome rages in some.”
And YOU are a prime example. Your baseless ego boosts you FAR beyond what you are ever capable of.
menicholas:
Atoms and molecules can only absorb photons with certain discreet energy levels.
That is true for GHGs, not for black bodies: a black body absorbs every photon of every frequency and sends out photons over a wide Gaussian range, with its peak frequency depending of only its temperature. See Wien’s displacement law:
https://en.wikipedia.org/wiki/Wien's_displacement_law
Toneb, what on Earth makes you think the calculated 255 K temperature should apply to the Earth’s surface, and not the Earth as a whole (which you agree is observed to be 255 K)?
So much anger, so much strawman, and so many errors. So little time in life. I think my children win again.
You’ll get past that anger. It will be OK.
Yes, you have to wonder what some people are on, to confabulate otherwise.
You have all forgotten Maxwell’s Demon, that could easily direct the more excited molecules continually to the warmer object for us. I nominate we call it the Al Gore’s Demon, and there must be myriads of them around doing AGW’s ( Al Gore’s Warming ) work. https://en.wikipedia.org/wiki/Maxwell%27s_demon
Willis says
“Short answer? Of course not, that would violate the Second Law of Thermodynamics … BUT it can leave the hot object warmer than it would be if the cold object weren’t there. Let me explain why this is so.”
If we are talking about TWO objects thermally isolated from the universe the answer is emphatically no.
What you have done is introduced an extra object
“it can do so in the special case when the cold object is hiding an even colder object from view.”
So now we have THREE objects.
Thermal energy in two form of EM radiation will be emitted and absorbed between three objects now instead of two.
The hottest object will also emit higher frequencies than the other two objects so a question of radiation quality is also important.
It is also helpful to consider the matter in terms of insulation
In this case radiative insulation.
If extra insulation(2nd object) is introduced the hottest object(1st object) will lose heat slower than before and so its own temperature will not drop quite so fast.
So if the 1st object is a person they will feel warmer for longer.
You are right to emphasise that heat flow will only occur spontaneously from a higher to a lower temperature.
If someone claims that the cold object heats the warmer object you can be sure they are not physicists.
Actually, it would violate the First Law of thermodynamics.
Part of the problem for a non-technical person is using temperature scales based on the freezing point of water. Sub-zero (or sub 32′) temperatures are assumed to have no “heat” which is not the case. It is sometimes quite difficult to explain that the Arctic in winter is radiating energy in the form of heat into space. The “temperature of space” is 3’K and the Arctic 250’K does not compute for many people.
I’ve probably displayed my lack of understanding here too!
Heck, most people have no understanding that coolness is not a thing.
Only lack of hotness.
Oh I don’t know. I might think your coolness is added upon by your hotness…and not a lack thereof.
Sorry…I needed the humor. 🙂
+++
Well, at least someone recognizes a joke wearing a science fact disguise.
Radiative gases within an atmosphere distort the dry adiabatic lapse rate slope to the warm side which reduces the vigour of upward convection.
The radiative gases therefore settle at a lower warmer height than would otherwise have been the case and radiation to space is greater from that lower warmer height than it otherwise would have been.
Therefore, conductive adjustments occur so as to adjust the amount of radiation to space from radiative gases which causes a neutralising of any surface warming potential.
Willis and those who agree with him would be right if radiation were the only means of energy transmission but it is not. Conduction and convection affect transmission of energy and also effect transformation of energy between KE (heat) and PE (not heat) with the net outcome being long term maintenance of hydrostatic equilibrium within planetary atmospheres.
The mass of an atmosphere (whether radiative or not) conducting and convecting provides insulation which allows the surface to rise above S-B.
The kinetic energy required to achieve such surface warming is from the reconversion of PE to KE in descending columns. That process is missing from the Trenberth diagram used by Willis which is why it has to be compensated for in the diagram by a proposed surface warming effect from DWIR.
That diagram shows sensible heat and latent heat via thermals cooling the surface in ascent but shows nothing for the warming effect in descent.
There is a simple well known observation that helps to choose between the radiative and non radiative surface warming proposals.
Observation shows that for planets with atmospheres in hydrostatic equilibrium the temperature within the atmosphere at the same pressure are similar regardless of vast composition differences adjusted only for distance from the sun.
The radiative theory cannot explain that whereas the conductive/convective theory does.
Stephen
Latent heat transport can only ever occur as part of a process of mass movement. I totally agree with you, it is not a radiative process. What I had never noticed in the Trenberth diagram, until you pointed it out just now, is that there is no downward return vector to balance the upward mass transport of air that occurred during precipitation. To balance the movement cycle downward motion must be present and clearly include both the cold rainfall as well as the falling dry air heated by adiabatic compression. And no, these two thermal processes (cold falling rain and warmed falling air) do not cancel out, there is a net heating of the atmosphere by latent heat of condensation as the phenomenon for the Chinook wind proves.
“What I had never noticed in the Trenberth diagram, until you pointed it out just now, is that there is no downward return vector to balance the upward mass transport of air that occurred during precipitation.”
It is always that way, and there are two explanations:
1. It is very difficult to measure.
2. If it was included it would make it obvious that the LWIR part of the process (including “back radiation”) is a quite small part of the whole heat exchange process in the atmosphere. Notice that the “convection arrows” are always shown as quite puny and discontinuous)
Not puny.
All the PE required to keep the entire mass of the atmosphere off the surface against gravity is involved.
That PE reservoir is the source of additional kinetic energy at the surface providing the observed surface temperature enhancement above S-B.
Philip,
You say: What I had never noticed in the Trenberth diagram, until you pointed it out just now, is that there is no downward return vector to balance the upward mass transport of air that occurred during precipitation.
That is because you were to aware that the two non-radiative energy transfers from the surface, for sensible heat (22W/m^2) and for latent heat (76W/m^2), are the net flows of energy due to these two phenomena. This is explained in the original paper that accompanied the original Trenberth diagram (I don’t know where Willis got his diagram from but the figures are in more or less the same ballpark as Trenberth’s and are definitely net figures.)
Please substantiate that.
Even Willis accepts that the net effect of convective overturning is zero so you cannot assert that the Trenberth diagram represents a net outturn.
Trenberth just erroneously includes the upward leg alone (leaving out the downward leg) and compensates for that omission by incorrectly asserting a surface warming effect from DWIR.
I have told you why and how convection changes to adjust the degree of radiative loss from GHGs to space so as to avoid destroying atmospheric hydrostatic equilibrium by warming the surface.
“Even Willis accepts that the net effect of convective overturning is zero so you cannot assert that the Trenberth diagram represents a net outturn.”
If Willis accepts that he is dead wrong. The reason is that convection carries molecules up so high that a large part of the latent heat freed by condensation/freezing radiates out into space and leaves the system. The same is true for part of the “dry” radiative cooling of the convected air. The entire mass, air, rain and snow ultimately comes back down, but it has always lost some energy on the way. The proportion lost is not large, but it is considerably larger than the energy lost by LWIR radiation.
The Earths atmosphere is a heat engine, but like all heat engines it is not perfect, it constantly loses heat to the surrounding environment.
tty
You are mixing up the radiative energy exchange with the non radiative energy exchange.
My point relates only to the adiabatic portion of the energy flow which is non radiative and fully reversible so myself and Willis are correct that convective overturning constitutes a net zero energy flow.
Where I differ from Willis is in pointing out that it was non zero during the first convective overturning cycle when the atmosphere was formed.
It is that non zero component that enables the entire mass of an atmosphere to participate in the warming of the surface above S-B.
Even if GHGs do work as proposed the mere fact that the entire mass of an atmosphere is involved renders GHGs insignificant but as I pointed out above the GHGs distort the lapse rate slope so as to radiate more effectively to space from a lower warmer level instead of warming the surface.
“You are mixing up the radiative energy exchange with the non radiative energy exchange.”
Not me, nature.
They are jumbled up in Nature but they are still discrete processes and operate as a counterpoint to each other in the way that I described.
Otherwise no long term hydrostatic equilibrium such that planets with any radiative component in their atmospheres (whether gaseous or particulate) could not retain those atmospheres.
Stephen Wilde November 25, 2017 at 2:39 am:
This may be irrelevant to your argument, Stephen, but I feel I should point out for the sake of clarity that your distinction between “heat” and “not heat” appears false to me.
“Heat” is not simply KE. In physics and thermodynamics, the heat content (a.k.a. enthalpy) of a body is defined as the sum of the KE and the PE contained by the particles that make up the body.
However, the body’s absolute temperature is simply a function of the average KE of its constituent particles.
Hence, the molecules of a block of ice at 0°C possess the same average kinetic energy as those in the equivalent amount of water at 0°C, but they contain far less heat and thus, far less potential energy too.
I don’t think the phenomenon you describe is as well-observed as you may think it has been. The data currently available to us about the temperature/pressure/chemical composition profiles of other planets’ atmospheres are still very scanty and uncertain. I think we would need to be much more certain of the reality of this alleged phenomenon than we are before we could use it as a test-criterion for the comparison of radiative versus conductive/convective theories. We might reach that degree of scientific enlightenment in a few centuries, perhaps, if we get lucky, but we’re nowhere near it now.
KE alone is heat. KE plus PE is energy so your point is wrong.
Many solar system bodies have had their surface temperatures measured and they are all very close to that predicted from the gas laws alone so that point is wrong too.
Stephen Wilde November 25, 2017 at 10:46 am:
My point is not wrong. Internal KE alone is also energy and that determines the body’s absolute temperature. PE is also energy and must be included in any calculation of the body’s total heat content.
Look, the fundamental definition of the “heat content” (a.k.a. “enthalpy” – symbol H) of a body is that of the “internal energy” (symbol – U) of its constituent particles plus the product of its pressure (symbol – p) and its volume (symbol – V). We may write this as:
H = U + pV
(See: https://www.thefreedictionary.com/enthalpy )
In this formula, the term U (internal energy) represents both the average kinetic energy (KE – determined by internal speeds of motion) and the average potential energy (PE – determined by the strengths of internal electromagnetic fields) of the constituent particles, so it is unavoidable that there is some PE in the heat content.
Then we have the pV expression, which represents the work that the body’s environment has had to do on it to bring it to the state that it’s in. That also adds directly to the PE of the body’s constituent particles (and indirectly to their average KE by increasing their average PE).
So the heat content of a body does contain both KE and PE components. QED.
Really? How many solar system bodies would that be exactly, Stephen? How accurate are the measurements of their global mean temperature and pressure profiles? And how many of those have greenhouse atmospheres? How many do not?
And finally, where are you getting your planetary data from? I hope it’s not some national, or multinational government agency like NASA or ESA, because their data is notoriously unreliable and untrustworthy for serious scientific purposes. It’s completely uncheckable, you see.
You’ve introduced one of Trenberth’s looney Earth’s Energy Budget Diagrams, Willis. According to Trenberth you are only getting an average of 169 w/sq.m of solar radiation impinging on the Earth’s surface, (you know, in certain places, melting the tar on roads in summer) ,but now you’ve also got 321 w/sq.m of this “backradiation” belting down from the atmosphere 24/7.
Is your hometown Loonyville, Willis? The people of Loonyville leave their bacon and eggs out on the porch overnight to have them cooked by the morning from the 321w/sq.m atmospheric backradiation.
I originally started to develope this issue when I read some posting purporting to prove the Stefan-Boltzmann law “wrong” based on lunar temperatures. You might find this link, regarding Newton’s law of cooling, of interest.
http://www.ugrad.math.ubc.ca/coursedoc/math100/notes/diffeqs/cool.html
The law gives this equation:
T(t) = Ta + (T0 -Ta)*1/(e^kt)
Where T(t) gives Temperature, T, as a function of time, t,
Ta is ambient background temperature, and T0 is the starting temperature of the body warming up or cooling off.
mass atmosphere = 5* 10^18 kg=5*10^21gm
temp atmosphere 255K (effective radiating temp to space- underestimates heat content)
specific heat 1.01 joules/gm C
5* 10^21*1.01*255= 1.288 * 10^24 joules
radius earth = 6400km= 6.4*10^6 meters.
area earth = 4 pi r^2 =514,718,540,364,021.76
240 watts/sq meter = 240 joules/sec per square meter
60 sec/min*60 min/hr*24hr/day=86,400 secs per day
5.147* 10^14 sq meters*240 joules/sec/sq meter *8.64*10^4 secs/day= 1.067*10^22 joules per day radiated away
1.067*10^22/1.288*10^24 = 0.83%
So the daily loss of heat of the atmosphere is less than 1% per day. That makes sense when you realized that although
temperatures may swing by 20 degrees K or more during the 24 hour day/night cycle, meteorologists are still able to make fairly accurate estimates of daily highs and lows for about a week- because of that temperature stability.
The above is to show that it is reasonable to assume a constant long wave
flux from the atmosphere over the course of a day.
We get an AVERAGE of 342 watts per day from the sun over earth’s surface. That works out to an average of 648 watts during the day and zero during the night.
You may have noticed that average temperatures do not increase to anywhere NEAR (648/390.7)^0.25 *288 K = 327 K during the day, and do not cool to anywhere NEAR 0 K during the night. That’s partly because MOST of the sun’s radiation gets absorbed by the atmosphere, which helps to moderate day/night temperatures. That 168 watts directly from the sun, as opposed from the sun to the atmosphere to earth’s surface, is entirely plausible.
“That’s partly because MOST of the sun’s radiation gets absorbed by the atmosphere”
But it is MOSTLY because of the oceans. Compare the diurnal temperature variation on Earth, Mars and the Moon. Which is the odd man out?
Or even compare the diurnal temperature swings in e. g. Central Asia and Polynesia.
True, thanks to the high specific heat of water, oceans act as a moderating influence, but my argument was that Trenberth’s hypothesis that most of the sun’s direct energy goes directly into the atmosphere still stands; else, how do you account for the ability of meteorologists to fairly accurately predict the weather for roughly a week in advance?
Mack,
You are perpetrating the common howler of failing to offset the 321W/m^2 back radiation figure against the 392W/m^2 forward radiation figure to yield a net upward flow (i.e. from surface to atmosphere) of 71W/m^2. Those two numbers cannot be cherry-picked independently.
Adding that true upward 71W/m^2 flow to the 22W/m^2 upward sensible heat flow and the 76W/m^2 upward latent heat flow gives a total upward energy flow of 169W/m^2 which EXACTLY matches the 169W/m^2 of Solar energy flowing down into the surface. As it must, for steady state temperatures to prevail!
For more details, please refer to my post of November 25, 2017 at 9:35 am.
It would be interesting if someone could resurrect the figure of how much the net 71W/m^2 is reduced by the molecules of CO2 released by man.
Well David,
You are going to have to explain this “common howler” to Dr Roy Spencer, because he is in doubt as to whether or not those energy flows even exist. He’s marked them with a big “X” here….
http://www.drroyspencer.com/2015/06/what-causes-the-greenhouse-effect/
Quoting Roy…”In the classical KT global energy budget diagram, the energy flows I have marked with an “X” would not exist without GHGs.”
I would like to say to the contrary, that, if those energy flows didn’t exist, then GHGs would not exist.
Roy goes on to say…”Now, recall I said temperature is a function of rates of energy gain and energy loss. Thus those energy flow arrows marked with an “X” in the above diagram represent huge flows of energy which can affect temperature, IF THEY REALLY EXIST”
So do they exist or do they not exist, David?
Also, I find it amazing the ever changing and extreme range variety of all these watts per sq.meters being bandied about by everybody…no actual measurements, just numbers seemingly out of thin air.
My guess is that the energy numbers marked with an “X” were pulled from the kiwi troughers ass.
Mack,
On November 25, 2017 at 10:08 pm you say: Well David,
You are going to have to explain this “common howler” to Dr Roy Spencer, because he is in doubt as to whether or not those energy flows even exist.”
I have no intention of doing anything of the sort. I put you right on an elementary conceptual error (which all too many people make) but apparently that has squashed your pride. The downward radiation must be subtracted from the upward radiation to get the net figure representing the ACTUAL flow of radiative energy, which is always from hotter to cooler body (surface to atmosphere). I even referred you to my earlier post of November 25, 2017 at 9:35 am for the rationale, which is based on standard textbook physics. And all you can do is to ignore the math and ignore the physics, rather than benefitting from the explanation.
However despite your obvious interest in grandstanding (“I would like to say to the contrary, that, if those energy flows didn’t exist, then GHGs would not exist.” etc. etc.), I will nevertheless indulge you by stating the following:
The 321W/m^2 downward radiation and the opposed 392W/m^2 upward radiation cannot be treated separately because they cannot be independently employed to do separate work. They are simultaneous and opposite – so only the net residual radiation, which is 61W/m^2 upwards, is capable of doing work. This is logically obvious when you think about it. Otherwise there would be an absurd imbalance at the earth-atmosphere interface. Which there isn’t. Otherwise the earth would have melted. Which it hasn’t.
Or, of course, you might be right and the diagram is wrong, in which case you have just discovered the most embarrassing scientific howler of all time.
Please just get over the fact that you (along with many other people, if that makes you feel better) have made an elementary mistake. If you can’t face up to that, you will for ever wander around in the wilderness of climate bloggery, blaming everyone else around you (me, Roy Spencer, Uncle Tom Cobley and all…) as you blunder on and on.
Or, for a change, you could think a bit and learn something new.
It’s your choice, mate!
“You’ve introduced one of Trenberth’s looney Earth’s Energy Budget Diagrams, Willis. According to Trenberth you are only getting an average of 169 w/sq.m of solar radiation impinging on the Earth’s surface, (you know, in certain places, melting the tar on roads in summer) ,but now you’ve also got 321 w/sq.m of this “backradiation” belting down from the atmosphere 24/7.”
It’s two-way.
Chicken and egg.
With there is 321 from GHE there is also that added to 169 solar to emit 490 from the surface >>>> which is then partially backradiated at 321 W/m2 and so on.
From Trenberth’s Energy budget diagram
Energy out:
22 + 76 + 392 = 490
Energy in:
169 + 321 = 490
The 321 is back-radiated having first being thermalised by the 169 SW absorbed AND the 392 added from the LWIR GHE.
Hi Toneb,
You cherry-picked your numbers and got the wrong answer. Don’t be embarrassed, it’s a common mistake. I have laid out the correct math, which balances perfectly with the incoming solar absorbed at the surface, a few items up-thread in my first reply to Mack (David Cosserat November 25, 2017 at 10:08 am).
Cheers,
David
Hi Toneb,
My profoundest apologies.
You are on the side of the angels. I should have read your previous post much more carefully. Of course you were quoting Mack’s misconceptions, not your own, and putting him right…
Best,
David C
Yes it can, with help. A reverse refrigerator. Air conditioning in a cold climate. All you need is a heat pump. What we will rely on for elctrical heating during the next ice age, hopefully all nuclear powered by then. Heat is removed from the colder body, making it colder, that heat is transferred to the hot body by the pump, making it warmer. First done in Glsagow taking heat out of the water supply, I don’t see that mentioned any more, just from ground or air, as in “sourced”. Performance factors are up to at round 4 as regards heat shifted to power in, Rather important given the cost of electrical energy for heating versus gas, about 4 times in the UK. Partly because gas heating is >90% efficient now but power stations energy conversion to electricity is a lot less, 60% at best for closed cycle gas turbine, 40% for the open cycle. Must dash….
brianrlcatt
Once you introduce a powered heat pump you are relying on convection and the gas laws rather than radiation so you simply confirm my point.
With a man made heat pump a separate source of electrical power is required.
For an atmosphere above an irradiated surface the necessary power is provided by gas parcels of different energy contents and densities working with and against the gravitational field as they each seek a height commensurate with their respective weights and energies.
The process nets out to zero energy consumption overall but for Earth that still requires an ‘extra’ kinetic energy worth 33C (or whatever) at the surface to drive the global pattern of convective overturning. Much more KE at the surface of Venus is required to drive convective overturning in such a heavy atmosphere.
And so it is with all planets with atmospheres.
Willis discounts convective overturning as a reason for the surface temperature enhancement on the basis that being a zero sum process it cannot add extra energy.
In fact it is only a zero sum process once hydrostatic equilibrium is achieved. The process of creating a convective overturning cycle is not a zero sum process. Rather it draws surface KE into atmospheric PE in preference to that surface KE being radiated to space and thereafter recycles that block of energy up and down indefinitely. It is an insulating process because conduction and convection transfer energy slower than radiation.
The downward leg of convection then heats the surface in addition to continuing insolation.
Even a wholly non radiative atmosphere will develop convective overturning due to uneven surface heating leading to density differentials across the surface so those who say that such an atmosphere would become isothermal are wrong.
Yes, headline should include ‘spontaneously’ but most people assumed that anyway.
A body in vacuum emits from the surface at some temperature. Add a cold fluid which gets heated by the body. Now, the same energy that was emitted by only the twodimensional surface, is shared with the volume of fluid. So, now we have both a surface emitting and a threedimensional cold fluid also emitting. But the energy supply from the source is constant, so emission from both fluid and solid body is sharing the constant limited heat flow from the source. In no way, this is a situation where the solid gets warmer.
The heat source has constant limited power(sun). Temperature is a measure of average kinetic energy per molecule. How can addition of cold fluid mass, which absorbs energy from the heat flow in a larger volume of molecules, result in higher average kinetic energy per molecule, than a smaller volume with less molecules at higher temperature?
It is not right. Just like adding water to a pot on a boiler plate makes the pot colder, adding a cold fluid to a warm solid body in space, makes the body colder.
The atmosphere is a heat sink, added to the ultimate heat sink of space.
Without the shell of the atmospheric cold fluid, the surface T would be:
(TSI/2pi*r^2)/4/3pi*r^3=510W/m^2=308K
With the shell of cold fluid:
(TSI/2pi*r^2)/(4/3pi*r^3)^2=383W/m^2=287K
Adding a heat absorbing cold fluid to a hot body cools it, only.
Prevost made the conclusion that the emission of a body depends on the internal state only. The atmosphere is definately not part of the solid surface internal state.
No.
(I don’t think I can constructively add anything to that. Just No.)
Aww shit! Good argument. I loose.
Keep denying the calculations, having faith in blankets and unicorns in greenhouses is your melody.
So Prevost was wrong then?
The emission of a body depends on the external state?
Come on, deny more of proven and applied physics. It´s fun to read.
In the history of this blog, there has never been a simpler, clearer, or more scientifically correct post; yet, we have all this irrelevant nonsense. Get a grip people.
Bless you, my son!
I agree. Everyone knows that dry ice, water and cold fluids in general, makes its heat source create more energy from nothing.
lifeisthermal:
Let’s say you’ve been outside on a cold winter’s day (255K, -18C, 0F) without heavy enough clothing. You have gotten hypothermia and your body temperature has dropped to 35K.
I offer to let you come into my house at 293K (20C, 68F), saying it will let you recover your body temperature up to 37C. By your logic, you would turn me down, because this is still colder than your body temperature, and it couldn’t make your internal “heat source create more energy from nothing.”
Seriously?
You describe a situation where a change in surrounding temperature results in less absorption of heat from my body. If I move to a surrounding environment where there is higher temperature, the surroundings will absorb less heat from my body. I will transfer less heat to the surroundings.
In what way does this support a claim where a cold atmosphere and increasing amounts of heat absorbing dry ice, causes increased temperature?
The principle of the gh-blanket is that increased heat absorption from the solid earth causes increasing output of power from earth surface. This is the exact opposite of your example.
The solid earth, is supplied with energy from solar heating. Without an atmosphere, it only has to heat itself. Adding a cold fluid which is heated exclusively by the solid body, not the sun, means that earth has to heat the atmosphere, in addition to the solid, simultaneously.
Earth provides the energy, from solar heating, for both surface emission and atmospheric emission, at the same time.
This is an inevitable consequence of continous heat emission from both bodies, cold fluid and warm solid. The sun heats the solid earth, which emits and transfers heat to the atmosphere. 4*244+383=1361W/m^2=TSI.
lifeisthermal:
You agree that moving from an ambient of 255K to 293K will result in lower thermal losses from your body, permitting the thermalization of your metabolic power to increase your body temperature. This is true even though the ambient temperature of 293K is less than your (reduced) body temperature of 308K.
By direct analogy, “moving” the earth’s surface from an ambient of 3K (which it would have with a transparent atmosphere) to one of, say, 255K, will permit the earth surface’s thermalization of solar radiation to increase its temperature. This is true even though the ambient temperature of 255K is less than the surface temperature.
The two examples are directly comparable, not opposite!
A transparent atmosphere cannot transfer energy to space, because it has no emissions. It does not require any continuous power input from the surface to maintain its temperature.
Can a current of photons travel in the opposite direction to another current of photons of greater intensity? I do not think so and infrared thermometers too.
Yes they can.
What, do you think they *collide* with each other?
And infrared thermometers too what?…
I remember helping out a presenter at public slide show. He had two projectors, and the audience was sort of in the way given how he left projector aimed at the left screen and right to right. I switched the two projectors so the beams crisscrossed which avoided hitting the audience. Worked fine, of course.
While there are photon-photon interactions, it takes an “astronomically” high flux to do anything measurable. I think it has been observed near supernovae.
As for infrared thermometers, some cold clear night this winter take yours outside and aim it directly upwards. It’s not seeing a black body, so the reading won’t reflect the true sky temperature, but whatever it sees will be a steady flux. However, it’s also seeing IR flux from the body of the thermometer and from the polyethylene lens, it uses an internal thermometer to compensate for that “noise.” The lens will cool quickly in the cold air and its flux will go down. The thermometer will reflect that by showing the sky temperature going down.
You may need an IR thermometer that will read low enough, I have a Kintrex IRT0421. Some people have found they can map the sky temperature to the water vapor content of the air column. Good tool.
An IR-thermometer works by measuring a gradient across a thermopile or thermocouple. It only measures the gradient inside itself. Then it extends that gradient into the surroundings with the s-b equation, by calculating the rate of transfer to different parts of the surroundings. It can only calculate the rate of transfer, from T1-T2. So, in the case of colder surroundings, it only measures transfer FROM the device. Because T2 is smaller, and the value is negative. Which will show as darker on the screen.
The manual will tell you this: that in the case of measuring cold atmosphere, the transfer to the device, the incoming flux, is negative. Which means: there is no incoming flux. The manual also says that the negative influx of heat, the non-existent incoming flux, is used to calculate a fictive incoming flux based on what temperature the receiver of heat transfer has, calculated by outgoing transfer of heat.
What this means is: the non-existing incoming flux, is imagined from the outgoing transfer and the device shows it as positive, even though it is not there. Because it uses the s-b equation and it can only calculate net-transfer. “Net” is the only transfer there is, because “net” is heat. And transfer of energy between bodies of different temperatures is heat. And there is no other transfer which can be calculated without breaking the 2nd law of T.
Another interesting fact: a thermocouple/IR-thermometer only have a range of some 25m into the atmosphere. So it doesn´t give much information about heat transfer in the earth system.
Optical measurement on the other hand, shows spectral distribution. But the problem is: they only show how heat flow decreases from the co2, by a very distinct “bite” which decreases intensity of emission in those wavelengths.
I’m sure the manual told me no such thing. If it did, my eyes would have bugged out, my pulse quickened, and I’d be on an epic rant.
Then my thermometer would display only one value from source colder than it.
Here’s the manual, https://www.homedepot.com/catalog/pdfImages/ef/effd4a5b-8452-4095-98ce-39265a0adde2.pdf . It’s disappointingly brief, and never mentions flux.
Willis,
I probably flatter myself if I consider that I am the gadfly the prompted this post, however as I always want to learn you will have to indulge me while I go through the following observations and resulting questions.
From first principles Science is the process of rejecting false ideas. So I will start by making statements which I hope we can easily identify as being false.
1. All forms of matter absorb (that is extinguish) all forms of light (electromagnetic radiation).
Trivially easy to prove false, because this statement denies the existence of transparent materials and also denies the existence of short frequency gamma rays and long frequency radio waves that can pass unchanged through material bodies of a specific composition. (Notice that already the caveats are creeping in), so matter in its various forms acts as a selective filter of electromagnetic radiation.
2. Absorption is the only process by which light interacts with matter. Again trivially easy to prove false because this statement denies the existence of reflection and refraction and not to mention the already discarded contention of no transmission.
3. Colour is a thermal process. Hum, now I am already getting into trouble because do I mean the emission of a specific wavelength from a hot object or the reflection of a non-absorbed wavelength from the surface of a cold body? Just for good measure what is meant here by hot and cold? Are we talking about the average kinetic property of a bulk material object or the specific translational momentum of an individual molecule, which supposedly has no temperature because temperature is a statistical measure of bulk particle motion, vibration, flexure, translation, rotation and not to even consider electron shell interactions of various kinds? (And no I don’t like the statement that an individual molecule does not have temperature because we measure the energy of translation of individual thermal particles using electron Volts).
Now for some questions:-
1. So what is colour? (Sorry dear Cos, I will spell that word the ol’ way). Let us start with the colour of an object perceived using reflected light. What is the process by which selective reflection occurs? Is it a process of absorption and immediate readmission or a boundary property of a material in which a process (perhaps similar to liquid surface iridescence?) occurs in a solid state material? Oh and just for good measure don’t forget that that liquids can also have colour, such as red-brown bromine or blue liquid oxygen, so is it that colour with reflected light is an electron shell process?
2. And what is black? We perceive carbon as being black and therefore having no colour, but this is wrong, carbon does have a colour, it is coloured infra-red, it is simply that we cannot see these reflected wavelengths and so describe carbon material as having no colour.
3. And then we come to the subject of absorption spectra. Helium was first discovered in the coronal gases of the sun because the astronomer Sir Norman Lockyer observed a unique yellow absorption band, evidence of an unknown element that selectively removed this specific wavelength from sunlight thereby dimming that wavelength when viewed from Earth. Is this not a similar dimming effect to that we observe with infra-red absorption spectra?
4. And what about the coloured light emitted by the discharge in a sodium light for example? Is this light the same process of light as I see reflected off the yellow walls of my bathroom? Well no. One colour comes from emission from a hot source and the other from selective reflection from a cold surface, so there are clearly different processes at work here that seem to me to be discounted at infra-red wavelengths.
So the key question for me is this; -How do we know that the selective infra-red frequencies that are blocked by the atmosphere are absorbed and therefore thermalise the absorbing gas and none of these infra-red wavelengths are reflected, in a perhaps recoilless process (or perhaps not i.e. radiation pressure?) that if so happened, might presumably “colour” the gas but have no thermal effect?
You Point 1, that is where the MIT Light bulb is wrongly classified, the IR screen does not absorb and then re-radiate the photon it reflects it. In other words they have found an Infra Red Mirror that allows white light to pass through, which is very clever physics indeed.
Thank you AC Osborn.
It has now occurred to me that because frequency is a conserved property, while wavelength varies with the refractive index of the transmission medium, I should not use wavelength to describe EM radiation.
Your style is very familiar. After a bit, I realised who it reminded me of – AE Van Vogt, a science fiction writer famous for making up his science off the top of his head, from ideas he got in his dreams.
To answer your question – yes, it might be reflected instead of re-emitted (although I don’t really think this is a controversy; there has been quite a bit of research done on the subject). But that makes no difference. We’re talking about back-radiation; radiation sent *back* towards the Earth from the atmosphere. Reflected, re-emitted, it still gets sent back.
And don’t tell me it’s the wrong wavelength or “colour” or whatever. It’s infra-red, and practically everything absorbs it to some extent, even objects that are slivered or painted white.
Well if “practically everything absorbs it” I wonder how it gets all the way through the atmosphere to impact the earth’s Surface from 100K away?
So you do not believe that “Wavelength” makes any difference?
OK.
I agree with Willis’s article, but I have an English quibble. The expression “than me” should be “than I.” “Than” is a subordinating conjunction, followed by a clause with its own unstated subject and verb. “He is taller than me” should really read “He is taller than I am.” The verb “am” is understood. “Than” is not a preposition, as “near” is; “near I” is obviously incorrect, and “near me” is correct, because “me” is the object of the preposition and has no following understood verb. “Than” can, indeed, be followed by “me” because “me” can be used as an object: “He likes Jenny better than [he likes] me.” On the other hand, “I” can be the correct pronoun if the sense is “He likes Jenny better than I [like her].”
John ==> eGads! that’s what my high school English teacher said after my speech in front of the whole student body accepting the office of Student Body Vice-President! She said it, of course, in front of the whole assembly — couldn’t help herself.
(I have, somewhat reluctantly, finally forgiven her after fifty some-years)
I’m faster than he. Oh no, I never could utter that. Germans might use als er, but Swedes could use än honom, ‘than him’. I’m not sure why I use than at least sometimes as a certain kind of preposition. In my own language, you can say something like I am her faster, or I am faster than (s)he. The logic probably is the same, it’s just that who said and why ‘than’ could not be a preposition requiring me/him/her.
Usually speakers are right, even if they are wrong. Than is by its etymology a conjunction, relative to when and then, so that would mean than I is historically correct. But what’s the ‘än’ though?
Color me confused.
There seems to be a general agreement on that there are 4 CO2 molecules in the atmosphere for every 10.000 other molecules.
Still, these 4 molecules are supposedly able to warm 10.000 of a different kind ?
By what mecanism, exactly ?
Sounds like a Perpetuum Mobile, to me.
They generally don’t, they generally reemit an IR photon of the same energy. However, if they collide with any other air molecule first, the vibrations between the CO2 atoms (that holds the energy from the photon) will be partially transferred as kinetic energy due to pushing both molecules away, and that means the temperature goes up. Over the next small fraction of a second subsequent collisions will heat up other molecules, restoring the bell curve shape of individual molecule’s kinetic energy.
Or so I understand, sorry I don’t have numbers and probabilities handy.
Ric, if you look up the mean time between collisions and the average emission time I think you’ll find it to be about 10,000 collisions per emission. So the small amount of CO2 in the atmosphere equilibrates with the atmospheric temperature
I defer To Dave Burton’s conversation with William Happer, https://wattsupwiththat.com/2017/11/24/can-a-cold-object-warm-a-hot-object/#comment-2676749
It says there are about 1 billion collisions per emission!
That means LWIR emitted by the Earth’s surface, winds up heating nearby air (and itself) as the mean free path of the photons is quite short. So that energy stands a good chance of going back to the ground, trees, whatever. And it implies that the radiant energy that escapes the surface is from wavelengths not blocked by CO2 or H2O. Something I get reminded of every morning I scrape frost off my car.
“By what mechanism, exactly ?”
You need to consider a photons path-length to space.
By the time it gets to ~ 8km more can escape to space than be back-radiated.
Shine a torch into a thin mist.
The beam will be attenuated at a distance.
Shine a torch in fog.
The beam will be attenuated more quickly.
Yes more fog droplets.
But also accumulated collisions because of the path.
Which is why there is no lab experiment that can duplicate the GHE in Earth’s atmosphere.
The photons come back … more fog-droplet collisions – then the brighter the back-radiated (refected – same concept) the beam.
By that mechanism.
You give an example of how radiation is reduced by mist and fog.
In what way is this a support of the gh-effect causing increasing levels of radiation?
“The photons come back”
WTF!
You are not shy at all!
Absorbed photons come back?
Lets talk about how you like to make things up.
Absorption of photons destroys the photon.
You have no clue.
For commenters who offer the argument “warm objects instantaneously reject IR from colder objects, please consider that you have defined a reflection.
The logical end point of this fallacy is that albedo is a function of energy content.
There’s a noble prize waiting for you if you can prove that one.
So Laser Directing mirrors get as hot as the Laser Beam?
Or are already hotter than the beam?
Clouds are “White Hot”, Ice is also “White Hot” and both hotter than Sunlight.
In your dreams mate.
Huh?
“The logical end point of this fallacy is that albedo is a function of energy econtent.”
First, albedo is necessarily a consequence of geometry. Irradiation on a disc, distributed over a hemisphere, absorbed in a volume, is enough to reduce the power density to 0.7i5.
Obviously, the temperature will determine the amount of ice, snow, sand, and water surfaces.
So, yes, albedo is a function of energy content. Measured as emissive power, T^4.
But geometry is the main constraint-
Thank you, Willis Eschenbach!
You’ve left out the fact that the Greenhouse Effect ALSO works during the daytime. (In fact, according to that diagram, it delivers more radiant energy to the surface than the Sun does directly, since a whopping 105 W/m2 of sunlight is reflected by the Earth and clouds.)
It’s a subject that’s insanely complicated in detail, but almost moronically simple in general terms. All you need is the ability to visualise, and and a bit of faith that scientists from more than a century ago (who never even heard of Global Warming!) are NOT trying to con you.
Love it “Faith Based Science”.
The world was flat and the Sun and stars revolved around the Earth, do you still believe it?
Ulcers were caused by stomach Acid, still believe it? Never heard of Helicobacter pylori?
Do you believe in the Standard Model, the Big Bang, Dark Matter & Dark Energy, with no proof and no actual evidence?
Because their are plenty of Scientists that don’t and have Theories just as good to prove it.
http://earthsky.org/space/erik-verlinde-gravity-theory-no-need-dark-matter
http://www.dailymail.co.uk/sciencetech/article-5109023/Dark-energy-dark-matter-NOT-exist-study-says.html
You seem to be suggesting that Scientists are never wrong.
Willis, thank you for writing this, I’ve wanted a decent post on the subject here to reference in the future. I apologize for not having written it myself years ago. You did a better job than I would have.
I guess we have nearly all the possible objections (and explanations) to what you describe. That could be a feature in its own right!
All right, I’ll take some time on this one.
I never said that scientists were never wrong, I said that these particular scientists are not trying to con us from political motives connected with the Global Warming controversy (mostly because they were all dead long before it started…).
If you think someone is trying to put one over on you, you have to pick up on every detail. Otherwise, a certain amount of faith is necessary for the maintenance of sanity. Massive objects attract each other. That’s a simple principle put forward by Sir Isaac Newton, and we trust it. It might suit us to believe instead that gravity is caused by the Flying Spaghetti Monster with His Noodly Appendages, but why should we? There’s nothing glaringly wrong with Newtonian gravitation, and even Einstein only modified it slightly with his Special Relativity.
There’s nothing glaringly wrong with the Greenhouse Effect. “It contradicts the Second Law of Thermodynamics” only works if you don’t understand radiative thermodynamics (or think that other people won’t, and hope to make a name for yourself through an invented controversy). If you’ve understood the basic underlying concepts, you can visualise the phenomenon in general terms, and it makes sense. If it doesn’t make sense to you, it’s because you’re introducing some rubbish such as “two lots of photons can’t travel in opposite directions at the same time”. (Yes, they can.)
Climate scepticism, on the other hand, is a different sort of thing entirely. When it’s not purely and simply political, it’s based on established science and attacks the *conclusions* and the *methods* of the warmers, not their scientific principles. (Their *moral* principles, now that’s another thing…)
I don’t need to start believing nonsense, just to maintain my street-cred as a sceptic.
Uncle Gus,
You say: …according to that diagram, it delivers more radiant energy to the surface than the Sun does directly
No it does NOT! The energy flow from the Sun that is absorbed by the surface is 169W/m^2. The energy flow from the surface to towards the atmosphere is exactly the same: 169W/m^2. The figures balance perfectly.
Take a closer look at the diagram…
Net upward sensible heat: 22W/m^2
Net upward latent heat: 76W/m^2
Net upward radiation: 392 – 321 = 71W/m^2
TOTAL: 169W/m^2
The mistake you have made is to look only at the 321W/m^2 downward component of radiation from the atmosphere and ignored the 392W/m^2 upward radiation from the surface. These two numbers cannot be dealt with separately. They are inextricably interlinked. You can’t have one without the other. You have cherry picked!!
For more details, please refer to my post of November 25, 2017 at 9:35 am.
“The energy flow from the Sun that is absorbed by the surface is 169W/m^2. The energy flow from the surface to towards the atmosphere is exactly the same: 169W/m^2.”
You are claiming that a surface at 288K is emitting only 169W/m^2.
Do you pee your pants on a daily basis as well?
Quoting Uncle Gus……”according to that diagram,it delivers more radiant energy to the surface than the sun does directly”.
No it does NOT! says David Cosserat..
Well, the diagram actually says this radiant energy from the “backradiation” is ABSORBED BY THE SURFACE.,David. So in Trenberth’s mind it is real and exists. It should cook bacon and eggs on the porch if left there overnight.
Incidently, Roy Spencer has doubts about the existance of these energy flows….
http://www.drroyspencer.com/2015/06/what-causes-the-greenhouse-effect/
Actually, you’re right.
I was considering only the downward radiation, and ignoring the upward. In total, they will balance exactly in the long run – they have to, or the earth would quickly burn up or freeze.
And of course, all heating (except a minute amount of geothermal) comes from the Sun.
But the diagram does seem to imply that the Earth’s surface is heated more by IR from the lower atmosphere than by combined IR and visible light directly from the Sun. That is some efficient blanket!
To be honest, I don’t know how accurate that or any of the other analyses of radiative heat transfer in the atmosphere are, or indeed can be. I suspect that without a lot more direct measurement, all we can get is a sort of rule-of-thumb sketch. I’m sort of assuming we have that much because, well, otherwise we might as well all go down the pub…
Willis, I am back with some more dumb layman questions.
You said that we can measure the LWIR coming from the CO2 in the Sky.
How do we do that?
How does the Measuring Device differentiate the CO2 from the rest of the Atmosphere between it and the CO2?
And how does it know it is LWIR?
We know it because we have tested the other atmospheric gases and know that only CO2 and Water will emit LWIR. So we measure the humidity calculate emissions from it and the rest is from CO2. As to how we know it’s LWIR you’d need to read the technical details for a given measurement device.
Actually all gases with more than two atoms in the molecule are GHG, and two-atom gases are too as a matter of fact, but only very weakly.
You miss the point completely.
You take a Sky Measurement, you get a Value, what is the value?, how do you know where it originates from?, and from what?
How do you measure the Humidity all the way up to the top of where it is with the measuring device that measures the Temperature?
The short answer, A C, is that satellites have sensors to detect whatever we want tracked.
No Satellites measure outgoing radiation, which shows more CO2 causes more atmospheric cooling.
They can’t measure Down Welling as it pointed away from the Satellite.
A C Osborn,
Some time ago there was a post at WUWT where two stations (Oklahoma and Barrow) measured the increase in backradiation caused by CO2 over the period 2000-2010, here a direct link to the article:
http://newscenter.lbl.gov/2015/02/25/co2-greenhouse-effect-increase/
Measured increase: 0.3 W/m2 for an increase of about 20 ppmv CO2.
Can a child shoot an adult?
Its not the cold object that does the warming, it is the energy it releases.
Wish we could “Like” on this page!
Willis: Very lucid explanation of a fundamental concept. When I engage in a discussion with someone, I have learned to quickly ferret out where the “bottom” is. That is, at what level is there agreement. Having a discussion at any level higher than that is generally a waste of time…if one is trying to resolve anything. At one point in my careers I was designing and making electrical power meters. I found that many of my customers, who ostensibly were trying to monitor electrical consumption, had no real understanding of the concepts of power and energy. Until that concept was understood, there was no point in engaging in any other conversation. Most of the time, I was successful in bridging that gap.
I cannot over state the importance of this general concept in communication. In the arena of AGW, I find the most fundamental/lowest level gap is the concept of the Scientific Method. In the realm of technical discussion, that’s pretty darn low (not sure you can get lower..:) )….unfortunately much lower even than the concept of radiation heat transfer.
Thanks for your excellent insights and writing skills…I always look forward to anything you write….
Regards,
Ethan Brand
Beautifully put!
Ethan
An important insight.
My work is with micro tomography systems – think hospital CT scanner but the size of a suitcase, sitting on a desk. We market these to scientists, mostly biologists. They often at first have no understanding of the nature of the technology, imagining it to have almost magical powers.
So you’re right – before any meaningful communication can occur one often needs to educate the client on the essential underlying science and principles, such as xray absorption and contrast (plus backprojection- reconstruction). Once that basis of understanding is reached, then more fruitful discussions can follow.
“…If there is a block of wood between you and a block of ice, if you remove the wood, you’ll get colder because you will be absorbing less radiation from the ice than you were from the wood. You no longer have the wood to shield you from the ice.”
That statement is wrong.
You’ll get colder because the ice will be absorbing more radiation from your body than when the wood was there.
If you were to use a sheet of aluminum instead of a block of wood, the block of ice would be absorbing more radiation from your body through the aluminum sheet than through the block of wood.
The sheet of aluminum will become warmer, this is because of the block of ice absorbing radiation from your body.
For a so called “cold body to warm a hot body”, its energy potential would have to be quantified, if you give the cold body a value of 2C and the warm body a value of 5C the differential between the two values would be 3.5C. if you consider the differential between the aluminum sheet and your body, this would be 4.25C.
3.5C>2C therefor the sheet of aluminum has warmed by 1.2C. This is in fact the block of ice absorbing radiation from your body through the aluminum sheet and not the other way around.
“The sheet of aluminum will become warmer, this is because of the block of ice absorbing radiation from your body.”
It’s sucking the heat out of your body!!!
Don’t get me wrong when I say that I absolutely love this. As the saying goes, it’s so bad, it’s not even wrong!
(And then not to make *any intelligible point at all* at the end of it all! Priceless.)
If you were to use a sheet of aluminum instead of a block of wood, the block of ice would be absorbing more radiation from your body through the aluminum sheet…
Uncle Gus
You’re giving me the impression that you believe that a persons warm body absorbs cold from a block of ice, are you for real?
I didn’t say “It’s sucking the heat out of your body!!!”
But a cold surface will draw the heat from a persons body, it’s called “heat transfer” not cold transfer.
Aluminum has less resistance than wood allowing the heat to leave the body to the block of ice more efficiently.
“This is in fact the block of ice absorbing radiation from your body through the aluminum sheet and not the other way around.”
Nevertheless, the absorption is the transfer of energy. Less transfer, higher temperature of source, increased transfer, lower temperature of the source.
It is important to locate the source of energy, by measuring the higher density of energy, to determine the direction of the flow.
Co2 increases absorption. Increased absorption means increasing rate of transfer. Increasing rate of transfer means lower temperature of the heat source.
lifeisthermal Says;
“Co2 increases absorption”
Not at saturation, Do you understand that atmospheric Carbon Dioxide is above its limit of absorption?
Do you understand that Carbon Dioxide has no further effect once saturated?
lifeisthermal Says;
“Increased absorption means increasing rate of transfer “
And
“Increasing rate of transfer means lower temperature of the heat source “
Not applicable on planet Earth.
In 1954, Hoyt C. Hottel conducted an experiment to determine the total emissivity/absorptivity of carbon dioxide and water vapor11. From his experiments, he found that the carbon dioxide has a total emissivity of almost zero below a temperature of 33 °C (306 K) in combination with a partial pressure of the carbon dioxide of 0.6096 atm cm. 17 year later, B. Leckner repeated Hottel’s experiment and corrected the graphs12 plotted by Hottel. However, the results of Hottel were verified and Leckner found the same extremely insignificant emissivity of the carbon dioxide below 33 °C (306 K) of temperature and 0.6096 atm cm of partial pressure. Hottel’s and Leckner’s graphs show a total emissivity of the carbon dioxide of zero under those conditions.
http://www.biocab.org/Overlapping_Absorption_Bands.pdf
Willis says: thermal IR emissivity is 1.0
What you are using for emissive is from water vapor not CO2. CO2 will not cause an increase in any temperature at thes concentrations or pressures.
That actually makes sense!
I think it’s wrong, and I don’t have time to read it carefully and figure out why it’s wrong, but at least it’s out of Looneyland for a change!
(If it wasn’t such a departure from the accepted science on the subject, I probably wouldn’t be so sceptical. Does anyone better qualified than I am have anything to say?)
Dr. Hottel wrote the books on radiative heat transfer in combustion chambers. His charts are still used today.
It is not wrong. At the temperatures and partial pressures we talk about emissivity of CO2 is essentially zero.
I challenge anyone to use these charts and show that CO2 has an emissivity that not essentially zero at partial pressure of .0039 ppmV and 273K.
Yes, it *does* say 33 degrees Centigrade! That’s hotter than I have my shower in the morning.
I still don’t believe it, but if true, think of the implications! CO2 effectively *transparent* to IR at the relevant temperatures. The whole Global Warming thing not a hoax or “settled science”, but based on a single unexamined (and fallacious, assumption)!
The irony!
Pity it’s BS…
mkelly,
I have read the reference, but that only talks about the influence of CO2 in the overlapping bands with water. The point is that most of the CO2 influence is in the 10 micrometer band, where water is not active at all…
feeling a little spunky, were we, Willis? 😉
thanks willis
watched these arguments for 10 years now. The cash analogy is pretty good. I may steal it someday.
the analogy, not the cash.
Why not fill a bulb with CO2 and compare (measure) the real contribution of CO2 in a “close” (sealed) word? This way we can know exactly the relation between filament and feedback temperature.
We could warm the filament at 50° and see how much at 400ppm of CO2 it will feedback.
Mariano,
If you have a bulb with a diameter of around 50 km, you may measure a difference, if you can fix all other variables…
Hello from France(so You will excuse the bad english… I hope
I love Your exemple with money, because it is the central dilemna.
Me give 100 to You
but instead off refunding 75 to me, You decide to spend 75 buying beer
the net flow is 100 to You, and I just have to fall in tears.
do’nt forget that if CO2 is a very good “interceptor of radiative wave, it is also a very good emitter
sure, the bulk of the atmosphere will be warmed by collisions with CO2,but at equilibrum, the flux will be the same.
In the dry desert, the surface of the grond will be very hot at noon, and the atmosphere surrounding also by conduction, and convection
When the sun fall, the grond can freeze, very quickly
But it all depend of the capability off the limit layer to radiate to space.
The theory is that, when it warm beneat, it cool upside and the radiative capability fall?
I doubt of that.
First, if there is more CO2near the ground, , (that the way the theory works?) more radiative flux will be intercept, and thus, it will be cooler in the upper limit.layer
But If there is more CO2 near the ground, there is also more CO2 in the limit layer, and thus a better capability to radiate to space.
If it is hotter in the ground layer, the atmophere surrounding will expanse, and the t°of the adiabatique curve will change, so any consideration of the t° at the limit layer will be modified.
Just for the fun
what if there is only CO2 in the atmosphere, no water on the ground?
nr65:
” In the case of the Earth, the solar irradiance of 1,368 W/m^2 has a Stefan Boltzmann black body equilibrium temperature of 394 K, 121 C, 250 F. That’s hot. Sort of.”
OK
“The Earth’s albedo reflects away about 30% of the Sun’s 1,368 W/m^2 energy leaving 70% or 958 W/m^2 to “warm” the surface (1.5 m above ground) and at an S-B BB equilibrium temperature of 361 K, 33 C cooler (394-361) than the earth with no atmosphere or albedo.”
You forgot to divide by 4 as 1368 is TOA.
The Earth is a rotating oblate speriod.
So that’ll be 342 W/m2 x 0.7 (albedo)
=239 W/m2 available (on average) for each m2 of the sunlit surface of Earth.
That gives a S-B temp of 255K
But we live on a planet at 288K
33K warmer.
Why?
Wrong place
Because we are a water world, Toneb. H20 not only dominates in the radiative arena, but also gives convective cooling at the surface.
Toneb, you write:
“That gives a S-B temp of 255K
But we live on a planet at 288K
33K warmer.
Why?”
As mentioned by others, Earth’s surface is not a blackbody. A blackbody is an object that only exchanges energy with its surroundings through radiative heat transfer.
The surface also exchanges heat with the troposphere via conduction (and subsequently convection).
Earth together with its troposphere, however, is a reasonably good approximation of a blackbody. The tropopause just above the troposphere ensures that there is no convective heat flow between the troposphere and the stratosphere. Conductive heat flow at this boundary is also small.
The average temperature of the troposphere is around 255K. Coincidence?
Back to the question, why is the surface 33 K warmer than 255 K?
Going further, why is the temperature at the tropopause 33 K colder than 255 K?
This is due to the lapse rate. Hot air rises and cools off. cold air drops and warms up. The end result is a temperature gradient with 33K warmer than the average near the surface, and 33K colder than the average at the tropopause. The average, 255 K stays the same.
–Just for the fun
what if there is only CO2 in the atmosphere, no water on the ground?–
I like fun.
Earth has 70% surface water and 30% land.
The average ocean surface is about 17 C and average land surface is
about 10 C.
So without water surface, roughly earth should have an average temperature
of less than 10 C
[Because the 17 C ocean surface 17 C currently increases the average land
Air surface to 10 C].
Ocean warms land and land cools ocean.
Land surface air temperature can be much higher, but basically
ocean saves money and lands spends more money that it makes.
Land dweller are in debt to the ocean, and always have been..