Discussion > GHG Theory step by step
EM-Thank you for your efforts. I'm always concerned that viewing this topic through the prism of GHG theory always brings us back to the same answers. Taking the process step by step should allow for more possibilities to be explored.
What about the work done in convection and lateral air circulation?
Schrodinger's Cat
Again, if your hypothetic planet doesn't rotate, how much of the surface will heat from sunlight and have the task of radiating all that heat away? Half of it. 255 does not apply. What is the expected albedo from a planet with no water, cloud or snow? You assume it's the same, which I regard as unlikely.
And that averaging again. The square metre at the equator at midday is receiving the full insolation minus it's own reflected portion.. The antipode of that is getting nothing and radiating at whatever temp it happens to be. You can't use a simple arithmetical average temp and put that into the S-B equation. Your 255k is way over-simplified to the extent of being useless.
rhoda
Scrodinger's cat
The SB equation is nothing to with greenhouse gases, nor are the energy budget measurements . They stand whatever mechanism you invoke to explain them.
What the greenhouse gas hypothesis does is provide an explaination which correctly predicts the observed energy flow pattern from known physics.
Whether the observed pattern of energy flow is due to greenhouse gases, pressure warming or leprechauns, whatever hypotheses you put forward have to pass that test. They also have to pass elementary tests of feasibility such as complying with the 1st and 2nd laws of thermodynamics.
This is why I keep pushing for more detail of your alternative hypotheses, so both of us can test the calculations for ourselves.
"What about the work done in convection and lateral air circulation?"
They distribute energy vertically and horizontally around the world, especially from the Tropics to high latitudes. This is why you can consider an energy budget for the whole planet and not just individual points(Sorry, Rhoda).
The energy driving these processes comes from the sunlight reaching the surface. Ultimately, in accordance with the 2nd law, it becomes heat and ends up radiated to space as IR.
While important in the context of energy flow within the climate system, they do not affect the energy balance of the planet as a whole.
Rhoda
The albedo of desert and dry soil are both around 0.3. On a planet with no greenhouse gases and therefore no water, that is all you would have. No oceans and no cloud. That is why I used 0.3 in my no GHG calculation.
For the with GHG calculation I used the albedo measured by satellites, distant space probes and earthlight reflected off the moon. That is also 0.3.
Entropic man
Scrodinger's cat
The SB equation is nothing to do with greenhouse gases, nor are the insolation/albedo/OLR energy budget measurements . Observed data stand whatever mechanism you invoke to explain them.
What the greenhouse gas hypothesis does is provide an explaination which correctly predicts the observed energy flow pattern from known physics.
Whether the observed pattern of energy flow is due to greenhouse gases, pressure warming or leprechauns, whatever hypotheses you put forward have to pass that test. They also have to pass elementary tests of feasibility such as complying with the 1st and 2nd laws of thermodynamics.
This is why I keep pushing for more detail of your alternative hypotheses, so both of us can test the calculations for ourselves.
"What about the work done in convection and lateral air circulation?"
They distribute energy vertically and horizontally around the world, especially from the Tropics to high latitudes. This is why you can consider an energy budget for the whole planet and not just individual points(Sorry, Rhoda).
The energy driving these processes comes from the sunlight reaching the surface. Ultimately, in accordance with the 2nd law, it becomes heat and ends up radiated to space as IR.
While important in the context of energy flow within the climate system, they do not affect the energy balance of the planet as a whole.
Rhoda
The albedo of desert and dry soil are both around 0.3. On a planet with no greenhouse gases and therefore no water, that is all you would have. No oceans and no cloud. That is why I used 0.3 in my no GHG calculation.
For the with GHG calculation I used the albedo measured by satellites, distant space probes and earthlight reflected off the moon. That is also 0.3.
Entropic man
You can indeed say known insolation figures can be used to provide the amount of radiation the planet must emit to maintain eqilibrium. But you can't assume the entire planet is emitting at the same average rate. It just is not so. Each area has to respond to the amount actually arriving on it, less local albedo and using a local figure for emissivity. On this planet right now there are places at 322K and others at 213k Arithmetical mean 267.5. Raise to t^4, add together and take the fourth root. 336K I think. Not the same. Your method is too simple. You can't use it for serious purposes. On top of that to assume you can use 0.3 albedo when the moon is 0.12 is risky.
rhoda
Entropic man: without going into a diatribe against Mr Huffman, can you explain why the calculations for Earth’s surface temperature, were it the same distance from the Sun as Venus, is exactly what is observed in the atmosphere of Venus, at altitudes where the pressure is Earth-equivalent? Coincidence, perhaps? If that is so, could it continue to be coincidence that, as the altitude increases, so the temperature profile remains surprisingly similar to that of Earth’s?
Radical Rodent
Here is another point of view.
Who woulda thunk that the consensus on life on Mars could be so long-lasting?
Radical Rodent
There are others who are not fully convinced about CO2 as a significant greenhouse gas, either. But… what does a scientist who has published hundreds of papers know about it, eh?
Others are even more critical:
So weak that warming from CO2 has never been measured.Where are your measurements that would disprove this idea, Entropic man?Purely theoretical.
Absolutely no CO2 warming signal in either satellite temperature record.
No CO2 warming signal in ocean sea levels.
No mechanism for warming a convective atmosphere or the oceans.
Radical Rodent
Ignore my calculated 322K, forgot to divide by two before taking the root. A better answer is 283K. Arithmetic mean was 267K. Showing that averaging two points arithmetically gives a different answer than what happens in reality. This all goes to show you cannot over-simplify.
rhoda
You would think, wouldn't you, that the penis-brains who insist on the first alleged ~33 degrees of GHG warming would be able to confidently, and correctly, predict the ensuing changes with further increments of atmospheric CO2? No?
Well perhaps they didn't get the water vapour feedback right in that fist 33 degrees of warming either.
Satan wept.
There is very little reason to think they have got any part of it right.
michael hart
Michael hart
My last few posts showed where the 255K came from. It is the temperature at which a planet with a non-radiative atmosphere radiates to balance the incoming radiation.against the outgoing radiation at Earth's distance fromThe Sun.
That is a planet with no CO2 and no water vapour.
This is supposed to be a science discussion thread. Remember that SB calculation are not part of greenhouse effect theory, but calculations of the relationship between the temperature of a a material and it's IR emission. Please critique my July 25 10..07pm post properly, rather than ranting, which you can do elsewhere.
I am not clear what you are complaining about. Are you saying that the SB equation is wrong? If so, please suggest an alternate way of calculating the radiation budget of a GGG free planet, including formulas and numbers that Schroedinger's Cat and I can check.
Entropic man
Radical rodent
This is not really a thread about greenhouse gases. It is about possible alternative hypotheses for mechanisms which produced the observed conditions.
As Huffman's champion, perhaps you can put forward equations which can be used to calculate the temperature profile of the Earth. Those here with some numerical skill can then test their validity.
Entropic man
Rhoda
There is a useful scientific technique called the black box.
You ignore all processes going on inside the box and just measure what goes on and out.
Do that for the Earth and you get a balanced radiation budget.
You are too focused on detail and your curious delusion about averages. Look at the planet as a whole.
Entropic man
New Studies Show Oceans Absorbing Atmospheric CO2 …”Putting Brakes On Climate Change”
By P Gosselin on 26. July 2017
clipe
Oops! Meant that for Unthreaded. Sorry for the intrusion.
clipe
Entropic man: if this is not a thread about greenhouse gases, why is it entitled “GHG Theory step by step” An important part of a theory are the parts that the theory refers to, in this case, greenhouse gases. You utterly dismiss the possibility that there may not be any greenhouse effect, and all claimed “greenhouse gases” are utterly irrelevant to the argument. This is the basic thrust of the Huffman argument, and he gives all the figures and calculations for you to play with at your leisure. Curiously, as I have already noted, I have yet to see anyone attack Huffman’s argument with any rigour; all they do is attack the man, often with great enthusiasm.
Another question that could be asked of you is: when has the Earth’s radiation budget ever been balanced? Look through history, and you will see that very rarely occurs, except, perhaps, momentarily as it switches from too much outgoing to too much incoming, and vice versa, else how was the Earth plunged into an ice age, and how did it rise out of it? Of course, such details seem to be beneath you.
You, sadly, seem unable to accept that this can ever happen naturally again, since the human industrial revolution; any variation since then, according to you, must have been caused by humans. The more realistic amongst us accept that we humans are but a small influence upon the planet – admittedly, a greater influence (probably) than any other species, but not really that much to write home about. There remain just two facts in this: 1) there has been a slight warming of the planet since the little ice age; and, 2) we are around to observe this. All else is just guesswork, assumptions and suppositions.
Radical Rodent
EM, you don't understand what I'm saying. That S-B over the disc versus outgoing radiation over the spherical surface gives a theoretic temperature. You cannot then expect to find the average temperature of the planet measured directly to match the S-B version. It requires a homogenous planet rotating at infinite rate before it will match. Now, climate scientist frequently compare a measured average at around 15C 288K with the S_B number of 255K and find a difference of 33C which they put down solely to GHG. That is not a valid comparison. The mere fact that so-called scientists continue to trot it out when it is blatantly wrong tells us all we need to know.
rhoda
The S_B temperature of the moon is variously reported as 267-270K
The actual measured average temperature at the equator of the moon is 206K. Everywhere but the equator it is pretty much bound to be less. http://www.diviner.ucla.edu/science.shtml
Now EM, explain how that is, on an airless rock. Let me help, it is because you are using over-simplified method which provide the answer you want.
Just to refresh: Where does 255K come from? From a theoretical radiation formula. Where does 288K come from? From a dodgy but adequate measurement system. How can you subtract one from the other and use the result to prove anything? You can't.
rhoda
When calculating the effect of solar insolation it is assumed that the illuminated earth approximates to a flat disc. This has been questioned.
https://tallbloke.files.wordpress.com/2012/03/response-to-unified-theory-of-climate.pdf
Schrodinger's Cat
EM I agree that the IPCC approach calculates a temperature of 255 degrees K (after an albedo assumption) compared with 288 degrees as measured. The difference is attributed to GHG. As rhoda points out above, the IPCC is wrong.
Schrodinger's Cat
Here is an interesting take on glowbull worming – as are the comments, and links therein.
Interesting to note on BBC Breakfast, this morning (27th July), we were introduced to an astronomer to talk about a collapsing star. Though the event took place over 9 BILLION lights years away, she stated, there was a notable effect in the upper atmosphere. Perhaps Svensmark is not as wrong as he is painted – especially when the astronomer slipped in the (unremarked upon) comment: “If this were to happen in our own galaxy, we would be toast.”
Radical Rodent
Radical Rodent - Interesting and thought provoking about the bubbles model.
Schrodinger's Cat
Schrodinger's cat
The standard approach is that the Earth intercepts an amount of power equivalent to the solar constant multiplied by the
cross section of the Earth in metres.. That is
1.366× 10^3 × π × (6.371 × 10^6)^2 = 1.74 × 10^17 Watts.
Watts are joule seconds Thus the Earth is intercepting 1.74 × Joules each second.
Regardless of any arguments about angles, latitudes, rotation or albedo that is energy which is no longer proceeding out of the solar system in its original direction.
This is basic geometry and physics. It makes me suspect that there are errors in your link and/or in the original paper
Halfway down the second page I found this.
The IPCC Approach
The earth, however, is a rotating sphere, and the problem of calculating the average irradiance is not
apparent at first sight. The IPCC made two assumptions to simplify the calculation:
1. At any point the half of the earth is illuminated and half is in darkness. Therefore, the IPCC
assumed a hemisphere illuminated by half of the irradiance and:
2. Since the surface area of a hemisphere is exactly twice the surface are of a disc with
radius, the effective irradiance is halved again:"
There is in error in 1.The side in darkness receives no energy, but the dayside receives all of the energy coming from the Sun, not half. . You cannot say that only half the surface is illuminated, so the planet only receives half the total incoming energy.. The author even included a formula containing the same error.
I have already redone the IPCC no GHG SB calculation on this thread using the full incoming energy and got the same temperature a as the IPCC. Nobody here objected.
If Dr. Sweger can misinterpret the IPCC so badly, what else is wrong?
Entropic man
Schrodinger's cat
EM I agree that the IPCC approach calculates a temperature of 255 degrees K (after an albedo assumption) compared with 288 degrees as measured. The difference is attributed to GHG. As rhoda points out above, the IPCC is wrong.
As I said above, a planet with no GHGs will be a dry desert. Deserts and dry soils have a measured albedo around 0.3. If you can make a good case for a larger or smaller albedo, please explain what it should be and we can try different SB calculations accordingly.
The point of this thread is supposedly to consider whether GHG theory is valid. We have not even reached that yet.
We are arguing whether you can calculate an average. This is niversally accepted among physicists and mathematicians, yet you reject them.
Even your Dr Sweger at Tallbloke's accepts averages.
Calculating the Average Temperature of the Earth
It can be something of a difficult problem to define what is meant by the average temperature of the
earth. Some have argued that there is no such thing as the “average” temperature; that temperature is
a localized measure. However, temperature is a measure of the energy in a system, and energy can be
averaged.
Entropic man
Schroedinger's Cat
As calculated earlier the Earth's atmosphere and surface takes up 240W/m^2 and radiates 240W/m^2 to space.
At a surface temperature of 288K the surface radiates 1×1×5.67×10^-8×(288^4-3^4) =390W/m^2
Two questions emerge.
1) Why is the surface radiation larger than the radiation to space?
2) If the surface radiates more energy than it receives from the sun, why does the surface temperature remain more or less constant?
The answer is that 390 -240=150W is somehow removed from the outgoing energy flow and returned to the surface.
My answer is that CO2 and water vapour absorb some of the outgoing radiation in the troposphere and reradiate it back onto the surface.
Any alternative hypothesis would need to produce the same 150W/m^2 energy recycling effect, whatever the mechanism.