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Discussion > An experimental demo of GHE.

BigYin, do you think it IS valid to compare the 'average temp' reached by the standard method with either the numerical or the observed? You might compare numerical and observed with the aim of improving ones model, but observed always wins. The standard model can't be improved. It is so idealised as to be useless practically. My final figure for the moon was 182K. There are some gross estimations in there to keep me in the realm of arithmetic, which I can handle. Let's say 180-205K, which bracket would cover many of the various sources. You still have 100K ish to make up to get to the Earth surface temps, provided by GISS and HADCRU. And how many factors are in there? Rotation, heat stored in rocks hotside and released at a lower temp coldside, water surface effects, local albedo, land use, clouds and no doubt as many more. Oh, GHE too. There is no way to achieve an argument as used by the IPCC and warmists that there is some fixed figure of difference which can only be made up by GHE. It just will not fly. Now, I don't think that argument was ever the sharpest arrow in their quiver anyway, but it is no good at all.


What does this say about N&Z and their ATE? Dunno. I think there is something there, but whether it is a big factor is not clear.

While I appreciate you guys all having to occsionally do some work, there's a pile of ironing in the kitchen, and I'm not going in there until it's gone.

Jan 9, 2013 at 1:19 PM | Registered Commenterrhoda

Jan 9, 2013 at 1:19 PM rhoda

And I have so many things to do that I haven't time to do any of them, so I'm going to take a nap.

Jan 9, 2013 at 2:58 PM | Registered CommenterMartin A

RKS

You cannot determine the conditions of an airless Earth using the same albedo etc as if it had an atmosphere and oceans.

That's not what I'm saying, please read this carefully.

N&Z say that since clouds are an artefact of the atmosphere, to compare airless with airless you have to remove the earth's almospeher,and in doing so, you remove the clouds, so you bring the albedo down to the same as the moon (from 0.3 down to 0.12).

They then go on to work out, using their particular brand of unrotating physics, that the SB temperature of the earth is some 150K cooler than current observed temperature... and THEREFORE the GHE/ATE has to make up this 150K.

This is not true, the re-application of an atmosphere means you have to re-apply the cloudy albedo again. NOT all of that 150K is down to the GHE/ATE, some of it, a large chunk, is down to the return of the cloud albedo. They can claim that GHE/ATE + increased albedo effect = 150K, if they like. But it's not accurate to pin all of it on GHE/ATE, that's having their cake and eating it.

Jan 9, 2013 at 3:11 PM | Unregistered CommenterTheBigYinJames

This is not true, the re-application of an atmosphere means you have to re-apply the cloudy albedo again. NOT all of that 150K is down to the GHE/ATE, some of it, a large chunk, is down to the return of the cloud albedo. They can claim that GHE/ATE + increased albedo effect = 150K, if they like. But it's not accurate to pin all of it on GHE/ATE, that's having their cake and eating it.

Jan 9, 2013 at 3:11 PM | TheBigYinJames>>>>

Thanks for making that clear.

Jan 9, 2013 at 3:26 PM | Registered CommenterRKS

I make the albedo effect something like 5%. When you are talking fourth roots, 0.88 is not much different to 0.7. Your point is good, but the difference is small (if I worked it out correctly). Oh, it's about a quarter of the difference between the two numbers. Well, well, pre-calculator maths still works.

Jan 9, 2013 at 3:30 PM | Registered Commenterrhoda

It was more an example of what I would call... creative polemics. Using a number which is not all GHE to demonstrate how 'obviously' it can't all be GHE. Appeals to the populum using dodgy numbers has no place in what puports to be a scientific paper.

Jan 9, 2013 at 3:36 PM | Unregistered CommenterTheBigYinJames

If I missed a post in here I am sorry (I have struggled to keep up with all the "scientific calculations) however I want to go back to something TBYJ said in here and repeated (even though challenged) on Dumbo's Slayer thread.
Long wave IR radiation from the Earth (caused by short wave IR frtom the sun) is absorbed and then reradiated by CO2 molecules. Some of this reradiated IR returns to the surface and warms it causing further reradiated IR from the surface. TBYJ did not say that this had been proven in the lab but surely this is a key point and one which RKS and TBYJ do not agree. Have either of you finished postulating an experiment to test this?

Jan 10, 2013 at 9:42 AM | Registered CommenterDung

Dung, some scientific effects only happen in the macro, and you can't reduce them in scale to make them happen in a lab experiment, I suspect GHE only happens in the wild.

By all means try, but as I said way back at the start of this thread... you're on a hiding to nothing. If you design an experiment and run it and it shows GHE, you've lost the bet. If it doesn't show it, there's endless scope for critics to point out that your experiment does not reflect reality in some dimension (size, voume, amount of insolation, lapse rate, etc) - so you wouldn't get the difinitive 'disproof' you were after. Trying to prove a negative is hard, which is why science doesn't often try it.

But the good news is you can try the experiment in the wild. Build your insulated container open to the sky, put your IR detector in the container, wait til night and measure the IR. If you get any, then it must be coming from the atmosphere. Job done. If you have a handy spectrum analyser, you can repeat the experiment and draw a graph of the mixtures of IR wavelengths in there to see what kind of thing emitted them.

Surprisingly you will see large peaks for H2O, CO2 and lesser peaks for other molecules.

This experiment has, in fact, been done. Here are the results.

So please, no more of this 'it hasn't been proved in a lab'. It's been proved in the wild, which is even better.

Jan 10, 2013 at 9:56 AM | Unregistered CommenterTheBigYinJames

Sorry, sometimes all this trying to disprove the GH theory gets me annoyed, because I think it's distracting from the main show, and I think it's unfortunate that a faction of 'skepticism' has got itself to a point that it feels it has to deny the existence of something there is a decent amount of evidence for, in order to say that AGW is wrong.

The GHE can be real and as large as claimed and AGW still be wrong

This is because where AGW is wrong is going to be in areas like the delayed temperature effects of increased levels of solar flux, badly modelled feedback mechanisms such as cloud albedo, inflated temperature records due to UHI and introduced statistical bias, reliance on unproven positive feedbacks... etc.

This used to be where the bread and butter of skepticism was - attacking poor statistical handling of temperature records, attacking UHI, attacking the models for not modelling clouds or solar flux.

I think the development of a strain of 'skepticism' which is attacking core physics is distracting, divisive, and in my opinion wrong and harmful to our cause. If the physics is wrong, it will become apparent, but we're going to get no traction on AGW by going there, instead driving up the one-way-street of fringedom leading to being sidelined.

Jan 10, 2013 at 11:14 AM | Unregistered CommenterTheBigYinJames

TBYJ

I truly understand the feelings you have relating to someone telling you a story that you do not want to hear (or asking a question). It is obviously not my intention to annoy you however you didnt really answer my question (not that you are in some way forced to do that, you are free to throw your hands up in despair at any time mate).
During the recent discussions you have had with others I was so impressed by every poster's mathematical abilities that I felt unable to contribute and had to retrench and go back to basic principles.
I have not asked for an experiment that replicates the atmosphere, simply the effect of a SW IR source in an atmosphere with varying CO2 levels on an earth type surface and an IR sensor to measure any reradiated IR from that surface. To use the hated cliche; it aint rocket science.
The experiment by Berthold Klein seems to have been too convoluted for people to bother with however it was (briefly) as follows:
In the wild, outside in full sunlight two Mylar balloons. One balloon had normal atmosphere and the second a series of atmospheres with increased CO2 levels right up to 100% CO2.
Mylar is totally transparent to all IR radiation.
Temperatures were monitored inside the balloons, in the air around the balloons, on the floor beneath the balloons and on the floor beside the balloons.
Changing the levels of CO2 in the balloons made no difference to the temperature inside the balloons or beneath them.
No GHE. Feel free to critique the experiment, all the details are in the long post I made earlier.

Jan 10, 2013 at 11:50 AM | Registered CommenterDung

The fact that an experiment is essential is shown when the opposition (in this case the totally dishonest Dr Iain Stewart in BBC's Climate Wars) have had to resort to fakery to try and prove the GHE. Stewart used CO2 in a glass tube to demonstrate that the GHE was real but obviously he must have known that glass is not transparent to long wave IR and that CO2 reradiated IR would heat the glass. That is the best they have got to prove that the GHE is real!
If they had better evidence why did they fake it?

Jan 10, 2013 at 12:02 PM | Registered CommenterDung

This is a very good example of what I said earlier, an experiment not being able to prove a negative. So what if the balloons don't change temperature? As you said yourself, mylar is transparent to IR, so any extra IR absorbed and re-emitted by the CO2 in the balloon will have gone out one of the other sides of it.

Consider (keep it in 1 dimension for simplicty)

Case 1: CO2 doesn't backscatter IR:
100 photons enter the balloon from the left, 100 from the right.
Nothing interferes with the IR.
Result: 100 photons exit from the right, 100 photons exist from the left

Case 2: CO2 backscatters the radiation
100 photons enter the balloon from the left, 100 from the right.
50 from the left are scattered and go back out the left, 50 keep going
50 from the right are scattered and go back out the right, 50 keep going
Result: 100 photons exit from the right, 100 photons exist from the left

Expand that for the remaining 2 dimensions.

In what universe would having CO2 in a balloon make it warm up, or the surrounding air, the air under it, or the ground beside the balloons warm up?

Jan 10, 2013 at 12:08 PM | Unregistered CommenterTheBigYinJames

And if the CO2 were outside the balloon, nothing would warm up either?

Jan 10, 2013 at 1:10 PM | Registered Commenterrhoda

The CO2 inside the balloon and the CO2 outside the balloon don't behave any differently.

I'm trying to think of an analogy.

Imagine a football field of people, all at arms length from each other, equally spread across the field.

Now at one end, say the on the right hand goal-line (the goal has been removed for this experiment), a line of officials start handing out footballs to the people closest to the goaline. Say 1 football every 10 seconds when a bell rings.

When the next bell rings, each person chooses one of the 6 or 7 people around them to hand the football to, but are instructed to choose a different person each time, to make sure the distribution is random.

Over time, the footballs make their way down the length of the pitch.

At any snapshot in time, many, approximately half, of the footballs will be going backwards towards the goal line again. At the goal line, some of the people may choose to give the football back to the officials, that's ok.

Eventually, balls reach the left hand goal line, where they can be handed off to another line of officials, if that last person so chooses on the bell ring. So eventually, footballs start leaving the pitch on the left.

This is a model of GH gases in the atmosphere as people, and IR photons as footballs. The balls being handed back to the original officials is the ground 'heating up' (i.e. having more photons than they started out with, and having to give away teice as many as before) - the steady state at the end is the IR escaping from the top of the atmosphere

All your balloon experiment did was to say, lets put a circular fence up on the pitch somewhere and cram in as many people as we can. Not at arms length, shoulder to shoulder. The ones at the edge of this tight circle can still hand out footballs to those outside and inside the ring. Yes, there may more footballs inside the fenced off area, but does it make any real difference to the number of footballs leaving on the left hand side of the pitch averaged over time?

The answer is... during the initial 'fill up', it will. A greated number of balls will enter thie tight fenced area than leave it.. at first. But over time, the balls will be coming out of the area only as fast as they went in, on average.

This is the same as the atmophere and your balloon.

Jan 10, 2013 at 1:36 PM | Unregistered CommenterTheBigYinJames

TBYJ

Watch this gold medallion I am holding, watch it swinging gently and reflecting all those photons yada yada yada yada.

OK I want to take you back to your 11 commandments (I always knew you were more powerful than the man upstairs hehe).
Here is a section of your commandments:

4. That some molecular gases, such as H2O and CO2 absorb certain known percentages of longwave radiation in this band. H2O takes the lion's share, but CO2 has a sizable absorption in this range. Proved in the lab.

5. Any particle which absorbs photons of any wavelength only has a few options. (1) to vibrate more - or heat up in lay terms, and transfer that kinetic energy to other particles through collison (2) to re-emit a photon of the same energy (3) a mixture of the two - increased vibration and emitting a photon of lower energy. Proved in the lab.

Here you are telling us that when the earth re radiates IR from the sun CO2 absorbs and re emitts some of the radiation but is warmed by some of the radiation. A mylar balloon with 100% CO2 should therefore be warming more than the Mylar ballon with normal levels of CO2 or did I miss something?

Jan 10, 2013 at 1:40 PM | Registered CommenterDung

A mylar balloon with 100% CO2 should therefore be warming more than the Mylar ballon with normal levels of CO2 or did I miss something?

Air has a notoriously small heat capacity at the temperatures we're talking about (graph). This means when it's making the decision about whether to vibrate or emit, it almost always chooses to emit. The CO2 probably did go up by a thousandth of a degree.

Jan 10, 2013 at 1:48 PM | Unregistered CommenterTheBigYinJames

So in a normal atmosphere with 400 ppm of CO2, the atmosphere warms by an almost unmeasurably small amount through longwave radiation from the earth?
Nasty devils advocate Dung ^.^

Jan 10, 2013 at 2:07 PM | Registered CommenterDung

Close, but no cigar.

Atmospheric heating by direct LW is not important, because it's tiny. As you saiy.

That's not where atmospheric heat comes from. All that interchange of footballs or IR photons means more hit the ground than are emitted. The ground heats to get rid rid of the extra energy. It heats by IR emission, and also by kinetic warming of the air. Warm air rises, we have a lapse rate. Voila.

Which is why it's always described as a 'back radiation' - the photons are omnidirctional but it's only the backscattered IR photons hitting the ground, which CAN vibrate and heat up which is the problem. 'Back radiation' is one of those misleading terms, like Greenhouse, which makes people doubt it.

If it was kinetic heating of the air that was important, there would be no lapse rate, because the CO2 would be heating all through the atmosphere equally. It's only photons which bounce back and hit the earth which cause kinetic heating, and then convective through the air to make a lapse rate.

Jan 10, 2013 at 2:23 PM | Unregistered CommenterTheBigYinJames

So what is the wattage of the CO2 contrbution to GHE today? If you have a handle on what it was as far back as possible, that would be nice too.

Again, not confrontational, I appreciate the education.

Jan 10, 2013 at 2:34 PM | Registered Commenterrhoda

Hard one to say with any accuracy because CO2 contribution is only a small part, H2O content is highly variable and it dominates the signal, but in theory, if you had hundreds of spectrum analysers pointing at clear skies all over the world for say 20 years, you could work out this figure and trend. But nobody is doing that. The only reason we have temp records is because they were useful for other things, nobody would propose measuring temperature either if we hadn't already done it.

Saying that, you can do a rough estimate. the DLR is about 290 W/m^2 on average. There is a debate going on about the exact contributions CO2 makes, but 25% of the whole effect in a dry sky seems to be the generally agreed quantity. Which would make CO2 contributing about 75 Watts.

Jan 10, 2013 at 3:07 PM | Unregistered CommenterTheBigYinJames

TBYJ

You say:

Close, but no cigar.

Atmospheric heating by direct LW is not important, because it's tiny. As you saiy.

That's not where atmospheric heat comes from. All that interchange of footballs or IR photons means more hit the ground than are emitted. The ground heats to get rid rid of the extra energy. It heats by IR emission, and also by kinetic warming of the air. Warm air rises, we have a lapse rate. Voila.

The atmosphere is not heated by radiation it is heated by conduction and convection, none of which has anything to do with greenhouse gases.

Jan 10, 2013 at 3:58 PM | Registered CommenterDung

That's true Dung. Unfortunately, the temperature to which conduction and convection attempts to heat it IS governed by greenhouse gases. It's not warmed by greenhouses gases, but the ground is heated by the extra photons that happen to be aimed downwards out of the thin layer of air near the ground, and the ground then heats ALL of the air.

Jan 10, 2013 at 4:23 PM | Unregistered CommenterTheBigYinJames

TBYJ

OK all I am interested in is CO2. Water Vapour does not come into the equation until greenhouse gases have already warmed up the atmosphere.
At less than one tenth of one percent of the atmosphere just how much do you think CO2 will warm the surface?
Do you not think an experiment would be a good idea?

Jan 10, 2013 at 6:53 PM | Registered CommenterDung

I'm sorry I didn't explain, we can't ignore H2O - it is the major greenhouse gas, its effect is 2.5 times the size of CO2's effect. Both H2O and CO2 backscatter IR, warming the surface.

Jan 10, 2013 at 6:57 PM | Unregistered CommenterTheBigYinJames

Ok, now to size the GHE. It's 290w/m2. Is that an average? Does it apply at night in the desert or by day in a summer arctic? Recent events here have made me reject averages as an input to anything. Can I look at it as a percentage of local insolation? Is the GHE ever saturated? I wonder whether it will handle 1366 watts the same as the 900 or so we get here. Or zero, every night.

Jan 10, 2013 at 7:11 PM | Registered Commenterrhoda