The Great Magical ‘Greenhouse Effect’ Self-Amplifying Loop

Anyone with even a slight interest in the whole climate issue thing should be familiar with the iconic ‘Earth energy budget diagrams’ allegedly quantifying – by accounting for the various energy transfer fluxes to, from and within the Earth system – the so-called “atmospheric radiative greenhouse effect” (rGHE) and how it forces the global surface of our planet into a mean steady state temperature much higher than at a pure solar radiative equilibrium. The prototype of these diagrams appeared in the Kiehl and Trenberth 1997 paper (K&T97) “Earth’s annual global mean energy budget” (Figure 1), apparently already there setting the gold standard for compiling these budgets, for its successors have all essentially been showing the same thing, with only minor modifications to the original.

Figure 1.

At first glance, the diagram might seem a bit confusing. What are we actually looking at here? What are we looking for? How to make any sense of it all? How to extract its core substance, its central message to the world? Robert A. Rohde of ‘Global Warming Art’ attempted to present the gist of the K&T97 Earth energy budget diagram like this:

Figure 2.

You will notice how, in Rohde’s rendition of the K&T97 budget, the energy being continuously supplied to the surface from the Sun appears to be completely disconnected from the energy later going out from the surface. 168 W/m2 come in, but 492 (!!!) W/m2 go out. And by all means, you will find that same peculiar decoupled relation in the original diagram too, even though it might be a bit harder to immediately hone in on.

So how do you get from 168 J/s/m2 – which after all should be the entire dynamic input of energy to the (surface) system – to 492? How can the output be three times bigger than the input? Easy. Just look at Rohde’s diagram. What do you see? What’s that in the middle, between the solar input to the left and the terrestrial output on the right? That’s the rGHE-postulated atmospheric ‘input flux’ to the surface. An extra input of energy. There it is. Just added in. And voilà! Now all of a sudden we have: Solar surface input flux, yellow arrow (168 W/m2) + atmospheric surface input flux, white arrow (324 W/m2) = 492 W/m2.

Yes, it’s that simple. That’s how they do it.

What you can clearly tell from (both of) these diagrams, then, is that the surface seemingly receives two separate inputs of energy, both contributing in setting the final steady state temperature of the surface. Meaning, they’re both in effect treated equally: as transfers of energy to the surface AS HEAT. There is no way around this observation. With only the solar input, the surface could only put out 168 W/m2 at a maximum of -40 degrees Celsius; with the direct addition of the atmospheric input, though, the surface is able to put out much more at a much higher temperature: 492 W/m2 at +15 degrees (after having subtracted the conductive/evaporative loss, of course: [492-102=] 390 W/m2).

The bottom line of all this? The common Earth energy budget diagrams, so prominently featured in the whole modern rGHE/AGW narrative, promote the idea that an amplified extra energy flux (the postulated DWLWIR one, the “back radiation”), somehow separate from the original solar input of energy to the system as a whole, comes back down from the atmosphere, directly adding to the solar input – as if it were an equivalent heat flux – to attain the final temperature and associated (directly through the Stefan-Boltzmann (S-B) equation) surface emission flux. This is summarised in that green internal loop designated “The Greenhouse Effect” seen in Rohde’s diagram.

But what is this loop all about?


The simplest, most widely advertised, and hence most commonly known, definition of the hypothesised rGHE is the one provided by the honorable “Encyclopedia Britannica” (EB):

“The Earth’s atmosphere acts much like the glass panes of a greenhouse: it allows sunlight, particularly its visible range, to reach and warm the Earth, but it largely inhibits the infrared radiation emitted by the heated terrestrial surface from escaping into space.”

First of all, this is not how an actual greenhouse works. It works by inhibiting convection. But that’s another story.

Other than this, there is but one problem with this purported description of atmospheric reality – it’s wrong. In fact, the opposite of what is stated is true.

The presence of our atmosphere here on Earth all by itself prevents about 45% (!) of the mean radiative input of energy coming in from the Sun from ever being absorbed by the global surface (as compared to the Moon). This is quite a spectacular reduction. And the reduction comes about purely from the atmosphere’s radiative properties (reflection and absorption of EMR). The evened out (mean) solar heat flux being absorbed by the global lunar surface is approx. 295 W/m2. The equivalent flux for Earth’s surface is a mere 165 W/m2; that’s almost 80% less power per unit area!

The global surface of the Earth, then, absorbs on average 165 W/m2 worth of radiative energy from the Sun. To stay in balance, the same amount of energy needs to be shed as well. That is, 165 W/m2 also needs to be released by the global surface on average.

And it does. ~53 W/m2 escape via radiation, ~112 W/m2 escape via conduction and evaporation:

Varmesyklusen

Figure 3. All values here are taken or derived from the Stephens et al. 2012 budget (Figure 5 below). (Full explanation of this diagram is given under Figure 7 at the bottom of this post.)

The atmosphere absorbs a bit more than 60% of the outgoing radiative flux from the surface, about 33 W/m2. The rest (~20 W/m2) goes directly to space through the so-called “atmospheric window”.

The point here is, these 33 W/m2 make up but a small part (15%) of the total amount of energy continuously received by the atmosphere: [33+112=] 145 W/m2 from the surface + 75 W/m2 from the Sun = 220 W/m2.

And here it comes: The atmosphere manages just fine to radiate this entire energy input, all of the 220 W/m2, out to space. In fact, that’s what it does. All of the energy absorbed by the air (from below and from above) is ultimately, in the steady state, converted into EMR and flung back out of the Earth system, courtesy of the IR-active gases and the clouds in the lower atmosphere (the troposphere). This is what they’re specifically tasked to do – cool the atmosphere (and hence, the Earth system as a whole). They’re not there to warm it. It would’ve warmed with or without their help. It could, however, not have adequately cooled without their presence. Because this can only happen through radiation …

In conclusion, it’s a weird notion, the one that’s gotten stuck in the collective mind of our society, that the atmosphere through its claimed ‘greenhouse gases’ somehow prevents radiation from reaching space, that because the atmosphere contains these radiating gases, then its radiating ability is reduced.

(And no, I’m not suggesting that the more IR-active gases in the atmosphere, the more it will radiate to space. It will always be restricted by the dynamic energy input, the energy available to be radiated to space: More energy brought into the atmosphere, more is radiated, less energy brough into the atmosphere, less is radiated.)

In reality, whereas the atmosphere only absorbs a radiative energy transfer of 33 W/m2 (in the form of IR) from the ‘terrestrial surface’ (plus 75 W/m2 from the Sun – 2.3 times as much!), it emits a radiative energy flux of 220 W/m2 (also in the form of IR) to space.

How is this in any way inhibiting thermal IR from the surface from reaching space!?!

Again, the atmosphere does the exact opposite of what is claimed by the climate establishment, of what most people have been taught to believe: It blocks a large portion of the sunlight from ever reaching the surface, but allows all of the terrestrial radiation transferred to the atmosphere – plus all the other energy being absorbed – to be emitted freely back to space.


But the EB entry on the rGHE doesn’t stop there. It goes on to suggest a direct violation of the 2nd Law of Thermodynamics:

Figure 4.

Note the general resemblance to Rohde’s K&T97-based diagram in Figure 2. This really is how the rGHE is pictured. The caption of this particular diagram reads:

“The greenhouse effect on Earth

Some incoming sunlight is reflected by the Earth’s atmosphere and surface, but most is absorbed by the surface, which is warmed. Infrared (IR) radiation is then emitted from the surface. Some IR radiation escapes to space, but some is absorbed by the atmosphere’s greenhouse gases (especially water vapour, carbon dioxide, and methane) and reradiated in all directions, some to space and some back toward the surface, where it further warms the surface and the lower atmosphere.

Encyclopædia Britannica, Inc.”

(My emphasis.)

This is by any standard quite frankly an appallingly stupid statement. What has the world come to, when perhaps the most rigorous, most respected and authoritative encyclopedia on the planet can write something like this in earnest, without qualification?

What is it that allows this kind of facile, slipshod treatment to pass off as a real scientific synopsis, a wishy-washy, sandpit-style rendering of what one after all is led to believe is a thoroughly understood physical phenomenon that profoundly concerns us all (it’s apparently what enables us to live and thrive on this planet, after all), a claimed recent strengthening of which is said to have caused (and to be causing) ‘global warming’ and ‘climate change’, a potential threat to civilisation as we know it, if we do not promptly commit to certain political and economical programs designed to overthrow the foundations of our modern post-industrial society?

The mechanism they propose here so directly and evidently goes against well-established physical laws, it is so clearly out of touch with reality, that one wonders why they still go to such great lengths presenting us with these falsehoods staring us right in the face, rather than formulating the real mechanism behind their posited radiative effect. One wonders, is there such a real mechanism at all, if they won’t state it? Is the effect even real?

What are they hiding?

And why aren’t anyone calling them out on this? Have we all become so sedated, so unable to think for ourselves, one independent thought?

What is it that lets them get away with writing this nonsense, in plain words – in a world-renowned, one would think, conscientiously fact-based publication on a serious scientific subject – that energy from a cool place (the atmosphere) will ‘further warm’ an already warmer place (the surface), even as the energy in question was originally emitted from the warmer place itself as energy loss, now later reabsorbed to do the same (warming) job a second time, sent back from the cool place? Why is no one objecting to and correcting such blatant drivel? There is no excuse. You can claim that “that’s not what they meant”, but it’s still right there, and unapologetically so. Why write it if you don’t mean it? If you know that writing it will only cause confusion. If you know that what you write is actually untrue, that it actually violates physical laws. Why not just write the truth? What’s really going on.

Well, what is the truth about the rGHE hypothesis?


The truth is that already its fundamental premise is false.

How is this premise expressed?

Like this: The surface of the Earth is at any one time able to shed three (!!!) times as much energy as it receives from the Sun, its only source of energy.

This means, in order to accomplish such an outstanding feat, it needs to continuously absorb energy also from somewhere else, other than the ultimate source, the Sun, even though this somewhere else couldn’t itself be an independent source of energy. Hmm. Just think about that one for a minute. Do you feel the absurdity trickling forth? One will have to assert that the surface, in addition to absorbing the solar flux of 165 W/m2, is somehow also absorbing a separate atmospheric flux of 345 W/m2 (i.e., one that is more than twice as powerful on average!) to make your already S-B-calculated numbers add up.

Somewhere along the way bells of some sort should’ve been set ringing …!

The reasoning behind this strange internal loop of self-amplifying energy fluxes points to a fundamental misconception of how real objects in the real world actually warm and cool.

I’ve discussed this particular topic before, in my post “How the IPCC turn calculated numbers into heat”. Three pertinent quotes:

‘Climate ScienceTM’ conflating actual energy transfer in a thermal exchange (heat) and radiances/potentials, mathematical terms in equations pertaining to ideal radiative situations, leads to slightly absurd approaches to how the energy from the Sun moves through the Earth system.

They basically portray the energy movement up through the troposphere as a diminishing one, not an accumulating one. They turn reality exactly on its head.

Their idea is that each layer of air going up absorbs some of the radiative energy for itself (or, rather, radiating it back down instead of up), leaving less to move on to the next. In their world this progressive absorption reduces the surface IR flux of 398 W/m2 to the ToA IR flux of 240 W/m2, a difference of 158 W/m2.

In reality, there is only the 165 W/m2 escaping the surface (same as coming in) while 240 W/m2 are (still) escaping the system as a whole through the ToA, an accumulated 75 W/m2 on the way up through the troposphere.

That is, instead of tracking the energy which actually leaves the ground, they track a calculated number based on their purely radiative black body view of the world.”

also,

A real-world object warms by increasing its internal energy. If we disregard ‘work’, such an object will warm as long as more ‘heat’ (energy transferred thermally from hot to cold) comes IN than what goes OUT. In between, the object ‘fills’ with energy. The surplus energy accumulates within the molecules of the object raising its general temperature in the process. As its temperature rises, its heat output also naturally increases. In the end, when heat OUT finally equals heat IN, the object stops warming. It has reached its steady-state temperature.”

and finally,

One has to – and this is essential – differentiate between the energy constantly moving in and out of the system (and each part of it) – represented by the energy fluxes, the ‘dynamic’ transfers to and from, the Qin and Qout – and the base fund of energy held inside the system at all times, its ‘static’ storage of internal energy (U). This is, so to say, the energy originally stocked up during warming before balance. Most of it resides in the ocean, but a fair bit is also contained within the soil, vegetation, ice and rock of the landmasses plus the atmosphere (basically, the troposphere). It’s there because these domains have mass and thus heat capacities. They warm gradually as they accumulate energy. Most all of the energy thus stored inside the Earth system originates from the Sun, but some also from internal (geothermal) sources.

This vast constant fund of energy is not itself a part of Earth’s running energy throughput. It’s a state property. It is simply the quantity that grows and shrinks (ever so slightly) from the ongoing dynamic process of IN vs. OUT. It grows if Qin for some reason becomes larger than Qout. And it likewise shrinks if Qin becomes smaller than Qout.”

By obsessing about the use of the purely radiative S-B equation in desiring to determine directly the IR flux emitted from the surface solely from its mean physical temperature (emissivity considered 1), the rGHE adherents completely ignore standard budgetting principles; they fail to account for the energy actually available to be emitted at each point in time. Starting with the already known (measured – estimated – averaged) mean global temperature, as they do, is simply starting at the wrong end. You have to start with the energy.

Remember, the budget here considers only instantaneous flux intensities, dynamic inputs and outputs of energy; not the total amount of energy contained within a steady state Earth system. The budget is there to simply balance the fluxes. The constant throughput of energy. Joules per second per square metre.

So you need to start out at the ultimate source of this energy, the Sun. How much energy does the Sun provide each second to the global surface of the Earth, on average? 165 J/m2. And that’s it. This is all that the surface has at its disposal at any specific time. This is the starting budget. There is no way you can exceed this amount at any later stage in the cycle. Because there are no other external inputs (disregarding the geothermal). All you can ever hope for is to balance the input with an equal output. In the end.

And this is exactly what we see. The surface absorbs 165 W/m2 worth of energy on average. And it in turn expels 165 W/m2 worth of energy on average. Balance. Remember, this balance is only reached at the steady state temperature, only then will the surface be able to shed as much energy per unit of time as comes in from the Sun. Before that time, some of the energy coming in will always rather accumulate inside (at/below) the surface, warming it in the process. But the warmer the surface gets, the more energy it is able to release per unit of time. And this progressively makes further warming harder. Until the outgoing reaches the level of the incoming. Then the warming stops altogether. The steady state temperature is reached.

Note, then, that the surface will start out by putting out 0 W/m2 and end at 165 W/m2 after warming up to the steady state temperature. The output cannot ever – and will never – exceed the input during a warming process. It can only strive towards finally matching it.

In the steady state, where we are, the majority of the energy escaping the surface of the Earth happens to do so through conduction+evaporation: 112 W/m2. All of this ends up in the atmosphere, warming it. What, then, are we left with? [165-112=] 53 W/m2. That’s the radiative output. No more, no less. No connection to the S-B equation in sight. This is only a question of accounting for the energy at hand. There simply isn’t 398 joules around per cycle to be emitted as EMR every second from every square metre of the globe. They are nowhere to be found. They don’t exist. There are only the 53 joules left. Regardless of any surface temperature. The steady state temperature and how it’s achieved is a completely different matter. It’s got nothing to do with how much EMR is instantaneously absorbed or emitted by it.

There is simply no point bringing in the S-B equation for the surface/atmosphere system. It is completely useless and irrelevant. Because this is not an ideal, purely radiative situation. It does not apply. You can scream and howl as much as you want at this. I’ll still say it again: It does not apply! The radiative transfer of energy from the warm surface to the cool atmosphere amounts to a mean of [~53-20=] ~33 W/m2. Because that’s all the energy that’s left to be transferred. Period.

Incoming energy accumulating at the surface or in the atmosphere before the steady state is reached will not be part of the energy transfers between the systems or to space. This is what the rGHE proponents do not understand. This energy does not add to the fluxes flying around inside the Earth system as a whole – that’s the “Eschenbach Steel Greenhouse” claptrap. It only adds to the internal energy – the U – of the surface or atmosphere, making them warm towards the final steady state temperature, building up the ‘base fund’ of energy held by the Earth system.

This is where the great misunderstanding (or, rather, deception) lies.

You can’t have the same energy both warming the atmosphere and then also warming the surface some more. Then you’re double counting. You’re using energy that you don’t have. Inventing extra energy. You let what you do have self-multiply. And by that, you’re breaking the 1st Law of Thermodynamics. Before you go on to break the 2nd.

Real objects warm from having absorbed incoming energy building up inside their mass (not in the space between them) – letting their U increase. This will happen as long as Qin is larger than Qout. In other words, before steady state is reached. The energy thus accumulating in the meantime will raise the object’s T, and will remain inside of it until you shut off the Qin – at this point it will start cooling, its U and T will drop.

This means that during the warming of the surface and/or the atmosphere towards their steady state, energy coming in from the Sun during each cycle will accumulate inside the systems, raising their U. This energy is then not available for also increasing the radiative fluxes in between the systems for each cycle. It is not free to also fly around amplifying fluxes!

What I’m trying to say is, you can’t have the cake and eat it.


Or, let’s try with a stale, goofy analogy. The warmists like throwing money analogies around, thinking these somehow prove their point. (They don’t, of course.) Their standard analogy normally involves a constant input of cash from some source, but then an extra input is introduced, back from someone you are kind enough to support, and then the idea is that you will thus somehow end up with more on average than if you only ever receive the original input from your source and never anything back from the guy you pass these money on to.

On its face it makes sense.

But this approach only works as far as inspecting one specific snapshot of the overall dynamic situation, one particular instant frozen in time, after you’ve received the extra money, but before you give it all away again. If considering the steady state in full, this analogy breaks down. And I’ll show you why:

Persons A and B both start off being broke. They have
no money. Then Person A starts receiving 200 pennies
(two pounds) from an unknown source once every other
second. But this guy turns out to be so generous that
he always directly passes whatever he’s got in his
hands on to his mate, Person B. Person B in turn
decides to also rid himself of all his money as soon
as he receives it, but he does it a bit differently – he
rather hands half of what he gets from Person A
straight back and the other half he simply throws
away.

How will this peculiar situation end up?

Person A: Every other second he receives the 200
pennies from his source, but also progressively more
and more for each round back from Person B, up to the
point of ‘steady state’, where he receives a full two
pounds back as well. But since he also gives away
progressively more for each round up to the point
where he continuously, every other second, passes on
four pounds to Person B, there is always at any one
time as much going out as coming in. So there is no
way he could ever save up any money for himself. In
other words, he has a constant dynamic througput
of money, he always has his hands on four pounds, but
always gives it away also, so the net can never exceed
zero. There is no storage, no stocking up of money
along the way, through all those cycles of money
changing hands. He is effectively as broke as when he
started, even though one could be tricked into thinking
he’s not. Because there’s always money passing
through.

Person B: For each cycle, he receives more and more
from Person A, 200 pennies plus whatever he himself
returned during the preceding cycle. This goes on up
to the point of ‘steady state’, where he every other
second receives four full pounds from Person A. But
since he at all times discards whatever money he gets
in, half back to Person A and half out the back door,
up to the point where he continuously delivers two
pounds in each direction every other second, he also
cannot ever save up any money for himself.

Bottom line, in this scenario, money is only ever
transferred, it is only flying around, back and forth.
It never gets to accumulate anywhere, creating real
wealth.

To eventually get rich (warm), these guys will have
to tuck some of the money coming in away for
themselves, take it out of circulation, so to say.

This highlights the difference between the two
approaches to ‘extra’ warming, the warming beyond
pure solar radiative equilibrium*: The ‘warming by
progressively growing instantaneous radiative
fluxes’ view (the one promoted by the rGHE adherents)
claims that the outgoing always matches the incoming,
from start to finish. The ‘warming by gradually
raising the internal energy’ view, on the other
hand, specifically makes the point that this balance
between in and out cannot be achieved before the new
steady state. Because, in between, some of the
incoming energy always rather goes into storage. This
view is promoted by … Mother Nature, the real world.

*Because, strangely the fans of the rGHE hypothesis
seem to adhere to the normal view of warming by
gradually increasing the internal energy when it comes
to the no-atmo situation. It is only the ‘extra’
atmospheric warming of the surface that apparently
comes about by steadily increasing the internal transfer
fluxes rather than the U.


Finally, referring back to the top two figures of this post, here is one of the more recent and updated Earth energy budget diagrams, the one from Stephens et al. 2012:

Figure 5.

If we were to refine this diagram into something a bit more elucidating, it would look perhaps like this:

'Drivhuseffekten'

Figure 6.

This diagram can be seen as the counterpart to the Robert A. Rohde one pictured in Figure 2, only accompanying the Stephens et al. 2012 version of Earth’s energy budget instead of the Kiel & Trenberth 1997 one.

Rohde’s closed internal “Greenhouse Effect” loop can be seen also in this diagram, only no longer appearing as something detached from the processes described, rather directly integrated into the overall energy cycle.

What do we see?

165 W/m2 from the Sun is absorbed by the surface. After the surface has equilibrated to this solar input, all of it is also presumed to be freely emitted back out. However, instead of reaching space, the reemitted solar energy enters the internal atmospheric amplification loop (Rohde’s “GHE” loop), bringing it back down to the surface from where it originally came, appearing as a flux separate from the solar one, and – in the steady state – with the amount of energy per unit of time amplified to more than twice its size. Subtract the conductive/evaporative energy loss, and you end up with the final radiative output from the surface: 398 W/m2 – solar + atmospheric. We’ve gone from an original potential max temp of 232K (with only the solar input (165 W/m2)) to a final steady state temp of 289K (with the atmospheric ‘input’ (345 W/m2) added).

Notice how the surface through the atmospheric rGHE loop ends up feeding itself with its own energy loss, in effect heating itself some more …

All this absurdity is readily explained by the central rGHE misconception that energy from the heat source (the Sun) during ‘extra’ (atmospheric) warming towards the final steady state accumulates in the dynamic transfer fluxes between the different domains inside the Earth system, gradually amplifying them, letting them heat more and more in both directions, rather than storing up as system internal energy (U).

I want you to compare the diagram in Figure 6, reality as promoted by ‘Climate ScienceTM‘, with the one in Figure 3, reproduced here for your convenience:

Varmesyklusen Figure 7.

What you will notice here is the direct connection all the way between the input and the output. The latter is totally dependent on the former. It does not exist as a separate entity. The energy – the HEAT – always moves one way and one way only, from higher to lower temperatures, meaning, Qin transfers from the hot Sun to the much cooler surface of the Earth, while Qout transfers from the warm surface up through the progressively cooler troposphere. The energy transport within the troposphere is carried out by the process of convection. The transfers of energy from the actual surface to the air above is achieved through radiation, conduction and evaporation, but once inside the troposphere, convection takes over (the release of latent heat, though, is spread out up through the air column). No energy in from the sun remains inside the Earth system after each cycle in the steady state. All that enters also exits.

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5 comments on “The Great Magical ‘Greenhouse Effect’ Self-Amplifying Loop

  1. Mr Pettersen says:

    The idea of using SB is totally bullshit. If you just look at a picture of a planet you see visible light returned from it. SB states that with no visible light the output will be pure heat. No planet have an albedo of a black body and thats even more true when you look at planets atmospheres.
    Look at pictures of earth, Mars and Venus. When you look at Mars you see the planets surface. When you look at Venus you see the top layer of the atmosphere and on earth you see clouds and oceans. What you actually sees are the planets albedo. It is not located at the surface on Venus and earth. The bb temperature of these planets exactly corresponds to these altidudes!

    So the correct way of energy flow are surface temp as a result of the normal gas law, an decrease in temperature by altitude, the so called lapse rate and in the end the radiation to space.

    So why do the hight of albedo/radiation have different levels for all the planets? Simply because thats where the colour changes and gives a contrast to reflect from. In the case of Mars there are no colour in the atmosphere and the reflection takes place from the surface. The surface temperature and the BB temperature for Mars are both 210 K. So with no difference in BB and surface temperature there are no Greenhouse effect on Mars!
    And that in an atmosphere with 96 % co2 and som other gasses that we call Greenhouse gasses.
    So either there are no IR on Mars or the Greenhouse effect are bogus.
    Since IR is the result of energy present thats obviously not the answer.SO if there are no GE on Mars there are no GE on earth as well. Laws of physics are the same for both planets.

    In short: Since co2 is a colourless and transperent gass it will not affect the albedo nor the outgoing BB radiation from any planet. Mars shows us that! So the only way to change temperature are by increasing incoming flux of energy!

    • okulaer says:

      Hi, Mr Pettersen.

      There is no connection between any layer inside the Earth system and its total (final) radiative flux to space. The evened out flux of 240 W/m^2 is simply balancing the incoming evened out flux from the Sun. The 240 W/m^2 could only correlate to a temp of 255K (through the S-B equation) if it all originated from one specific blackbody surface alone. It doesn’t, so the connection is dead.

      You mention looking at a picture of a planet and seeing visible light returned from it. And you’re correct, the only reason you see the planet at all (like the Moon at night) is because of the reflected SW light from the Sun. Because of the ‘albedo’. This goes for all things in our everyday life as well. Everything we see on Earth which in itself is too cool to radiate visible light, is visible to us only because it reflects visible light from other sources of energy, either from artificial ones or from the Sun. Our eyes cannot see the radiation actually being emitted by these objects themselves.

      But the satellite instruments measuring the radiation from the Earth into space specifically distinguish between wavelengths, so reflected SW and emitted LW (thermal) radiation are kept separate.

      The whole Mars thing is interesting indeed since, as you mention, there is rather compelling evidence that the actual global mean surface temperature of the planet is no warmer at all than the blackbody temperature estimated from the radiative flux to space, and so according to theory, there is no atmospheric radiative GHE on Mars.

      But this isn’t as straightforward as one would think. Because Mars, if it didn’t have an atmospheric insulating effect, should’ve been much colder than the blackbody temperature. Like the Moon. The BB temp of the Moon is about 269K, but its real surface temp is less than 200K. This discrepancy is explained by the huge temperature differences between night and day and from equatorial to polar latitudes across the lunar surface. We should’ve had the same thing on Mars, but we don’t. So there is actually an atmospheric warming effect on the red planet as well. However, it is not due to atmospheric radiation, but to atmospheric mass (weight and heat capacity) and advection.

      • Mr Pettersen says:

        Your statement about no common surface will make the use of SB even more wrong. No surface albedo=no SB calculation. So why are the scientist so hung up on the BB radiation from planets? Where is it written that surface pressure cant give higher temperatur than the BB radiation?
        The temperature from the surface pressure are a seperat and indipendent source of warming and for most planets it is higher than the incomming radiation. But for other planets its less.
        I see no problem with that and it will not brake any laws of physics either.

  2. RealOldOne2 says:

    Kristian, The first two image links in this article appear to be broken. But they still exist in the wayback machine here: https://web.archive.org/web/20170710112733/http://www.windows2universe.org/earth/Atmosphere/images/earth_rad_budget_kiehl_trenberth_big.gif
    and here: https://web.archive.org/web/20170710104002/http://www.windows2universe.org/earth/Atmosphere/images/earth_rad_budget_gwa_big.png

    Thanks for writing and maintaining this blog.

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