Tuesday, 9 June 2020

The Greenhouse Effect - 99% of what you'd ever need to know in one chart.

This will be one of the first chapters in my book, if I ever get round to writing it.

1. Work out total mass of atmosphere of Mars, Earth and Venus per m2 (divide surface pressure in Pascal N/m2 by acceleration due to gravity m/s2).

2. Work out 'effective temperature' (based on incoming radiation W/m2, albedo of surface/cloud cover, Stefan-Boltzmann constant 5.67/10^8).

3. Work out lapse rate (acceleration due to gravity m/s2 ÷ specific heat capacity of constituent gases based on temperature at hard surface J/K/kg)

4. Work out hard surface temperature by adding lapse rate x altitude of "mean radiating altitude" (which to all intents and purposes is the same as the average altitude of cloud cover, that being the first thing the solar radiation interacts with when it hits a planet and the thing which on which albedo is based).

For clarity - steps 3 and 4 are just for fun. You can skip these and go straight to step 5 - the actual measured hard surface temperature - because that is the one you subtract from 'effective temperature' (from 2 above) to calculate the total Greenhouse Effect!

5. Look up actual average surface temperature in K and make sure it tallies with your answer 4.

6. Subtract 'effective temperature' from actual hard surface temperature to find magnitude of The Greenhouse Effect. Plot the results for all three planets against mass of atmosphere/m2 using logarithmic axes and add a line of best fit.

7. Oh my, it's all a straight line. Which is what you'd expect anyway:

8. It's a shame that our estimates for the total mass of the Gas Giants and their temperature at the core i.e. their hard surface are so vague, it would be nice to see if they fit the pattern.


Dinero said...

In the Greenhouse effect thesis the altitude of the mean radiating altitude varies with atmospheric composition, and so the atmospheric composition is included in establishing the straight line.

Mark Wadsworth said...

Din, I'm sticking to the REAL greenhouse effect, which is based purely on mass of atmosphere per m2. There's no evidence for any other kind.

Dinero said...

I am pointing out that you are using the mean radiating altitude and that is established from the effect of greenhouse gases, and so what you are describing does not differ from the green house effect described by green house gas adherent climatologists.

Mark Wadsworth said...

Din, nope, I'm not.

I did steps 4 and 5 as a reality check, the two should tie in (and they do, obviously for the reasons I explained and are widely accepted, unless you work for NASA and do the whole things arse backwards).

But the Consensus way of working out magnitude of GHE is find actual surface temp and subtract 'effective temp', which is exactly what I did. (personally I think that is a conceptually flawed approach, but hey, I am playing by their rules).

The bit that the Consensus glosses over, for obvious reasons because it would give their game away, is to correlate GHE with mass of atmosphere per m2 (rather than some fairy tales about CO2). That is the only potential point of disagreement here!!

Dinero said...

Are you having a laugh !!! That is exactly what you did in steps 4 and 5 !!!

In Steps 4 and 5 you explicitly calculated the expected surface temp using the lapse rate and the mean radiating altitude.

As I said before the lapse rate itself plays a part.

Mark Wadsworth said...

Din, I clearly know more about this than you do.

Read that Hansen gibberish - he compared ACTUAL hard surface temp (my step 5) with 'effective temperature' (I used the traditional way of calculating this, the same as he did and everybody else does), the difference = GHE

Hansen worked out the lapse rate by dividing GHE by the altitude of the "mean radiating altitude". (I worked out the lapse rate the proper way step 3. But that is IRRELEVANT. I think I made it clear that I did step 3 and 4 as a check. Step 3 and 4 are not actually necessary if you calculate GHE the childish Hansen way. )

Mark Wadsworth said...

Din, I refer you to my sentence...

"5. Look up actual average surface temperature in K and make sure it tallies with your answer 4."

They clearly tallied! Those are the rules!

Dinero said...

Your last comment is irrelevant and completely evades the point that you are using data that according to the GHE inherently includes the effect of greenhouse gases. It is quite possible that you have not picked up on this after I have pointed it out over a few weeks. And the comment "I clearly know more about this than you do." is inappropriate because I am being polite, and so my comments are not as assertive as they would be otherwise. And I am the one who sent you the link to the paper!

The reason that the figures tally is a mathematical tautology ! If you take a real temperature at a real altidue and work down to a lower altitude using a real lapse rate you get a real temperature that exists at that altitude. That is described in the Hansen paper and elsewhere.

Mark Wadsworth said...

Din, thanks for the link to the paper, the motherlode of crap.

I am using data that INHERENTY correlates mass of atmosphere with difference between ACTUAL hard surface temp and 'effective temp'.

I know exactly what I am doing.

All that matters is MASS. One kg of CO2 has same effect as one kg of N2 or one kg of O2. Do you not understand that?

I did 3 and 4 as a check. The table is based on ACTUAL hard surface temp and 'effective temp'. Altitude of "mean radiating level" does not enter it. Just MASS and the difference in K between 'effective temp' and actual hard surface temp.

I did the spreadsheet, I have studied the ways of the Consensus. I can out-calculate these cretins any day of the week.

I'm not sure how many times I have to explain these few simple steps in which "radiative forcing" and all that crap PLAY NOT PART WHATSOVER.

Dinero said...

Where, ie, how, did you ascertain the altitude in the atmosphere from which you work downwards - using the lapse rate, to ascertain the expected surface temp.

Mark Wadsworth said...

Din, I was using Hansen's figures (or the current accepted values). They appear to be widely agreed (within margin of error) and reconcile nicely with predicted and actual lapse rates, average height of cloud cover etc as cross-cross-checks.

Not that it matters. I only did 3 and 4 as a cross check to make sure they agree with ACTUAL hard surface temp, which is what went into the chart (they did agree, of course).

Unlike Hansen, I don't just make up numbers to suit my purpose. Or work arse backwards. I work forward, backwards, diagonally using as many sources and ways of calculating something as possible.

(There are - for example - different estimates of albedo, and I took most widely used values, or middle of range where different people give different values. I don't make stuff up. If somebody found some actual evidence that CO2 has the slightest impact on temperatures, at the hard surface or anywhere else, then I would check it carefully and accept it if it made sense. It doesn't of course because there is no such evidence. A straight log/log straight line is pretty clear cut evidence if you ask me).

Dinero said...

You were using Hansens figures. And what I am pointing out is those figures are for an atmosphere with the GHE and so the GHE is incorporated in your results.

Mark Wadsworth said...

Din, FFS, I calculated GHE the same way Hansen did and everybody else does. Actual hard surface temp minus effective temp. Where does altitude come into that? It fucking well doesn't.

Do you need altitude to calculate effective temp? No.

Please tell me which of these two variables depends on altitude...
- actual hard surface temp minus effective temp,
- mass of atmosphere per m2?

Those are the only two variables that are plotted on that graph.

Mark Wadsworth said...

Din, this sentence shows you don't have a clue what you are talking about;

"the GHE is incorporated in your results"

The GHE is exactly what I am showing!!!

That's like me plotting hourly wages and you saying "you incorporate hourly wages into your results" as if that were a mistake. Duh.

Mark Wadsworth said...

In case that is not clear, the chart is headed "the greenhouse effect", the horizontal axis is labelled *mass of atmosphere in kg/m2" and the vertical axis is labelled "the greenhouse effect".

To criticise this chart on the basis that it "incorporates the greenhouse effect" is beyond laughable.

Dinero said...

You really are having a laugh !!!!

You have been BANGING ON ABOUT ALTITUDE FOR THREE MONTHS and I HAVE been telling you for THREE MONTHS it is a red herring.

However since then, and on the plus side, we have ascertained that the lapse rate is part of atmospheric science.

Mark Wadsworth said...

Din, the lapse rate is part of atmospheric scienxe, I never said otherwise.

A chart that plots GHE against mass of atmosphere per m2, is exactly that. A chart that plots GHE against mass of atmosphere per m2. Nothing more, nothing less. Altitude has fuck all to do with either of those two variables.

Mark Wadsworth said...

Besides, you are the one fixated with altitude, I was the one saying it's a red herring. My view, which is correct on the facts and backed with logic, is that the "mean radiating altitude" and the altitude of the cloud cover are pretty much the same thing and no great mystery.

ontheotherhand said...

As I have said before on climate, unless one wants to go do a degree on it, one has to trust 'the right sort of people' to do the work for you. I trust you MW. I don't know that there is a book deal in this though for you. I really like physics and counterintuitive ideas, and I'm above average IQ, but I can't follow this without putting in some real effort. I get the whole gas temperature pressure thing. Most people struggle with that. For example, most people thing that the reason a spacecraft reentering the atmosphere gets hot is friction, but it is not. It is that the spacecraft is like a piston squashing the air in front of it. It is pressure.

Mark Wadsworth said...

OTOH, we can't "understand" the Consensus explanation because it is all self-contradictory obfuscation. That's their whole game plan.

But the truth is there is a very real Greenhouse Effect, we are only arguing over WHY it exists. You can go down the CO2 rabbit hole or just accept that the GHE is proportional to mass of atmosphere/m2. I'm sure if I merge all their equations into one master equation, it will boil down to exactly that.

Which also neatly explains why the cores of Gas Giants are insanely hot, even though they are mainly H and He - which by Consensus definition are not 'greenhouse gases'. Or why nuclear fusion starts in stars - they need temperature and pressure to kick start it.

"For example, most people thing that the reason a spacecraft reentering the atmosphere gets hot is friction, but it is not. It is that the spacecraft is like a piston squashing the air in front of it. It is pressure."

Now that IS interesting, I'd never thought about it like that.

ontheotherhand said...

If it were friction, they would make the reentry vehicle streamlined and take a shallower descent. They purposely put the blunt end first so that a cushion of air is trapped and somewhat insulates the ship from the intense heat at the front of the shock wave.

ontheotherhand said...

And for that matter, for your motoring interest MW - pressure is how a diesel engine ignites without a spark plug

Mark Wadsworth said...

OTOH, yes, but the diesel example is normal small scale gas laws, compress it and it will heat up. Leave it a bit and the heat will spread out evenly again. Within a gas cylinder on a small scale where you can ignore gravity, temperature and pressure are the same everywhere.

The atmosphere works a bit like a fridge, it cools and warms simultaneously, it makes the top layers cooler than you would expect from incoming sunlight (like the inside of your fridge) and makes the lower layers warmer than you would expect (like the rest of your kitchen).

This goes hand in hand with higher and lower pressure.

That is the bit that many people don't get, you can leave the atmosphere as long as you like, the lower layers will always be warmer and at higher pressure than the upper layers.

There's a simple, inarguable and easy to understand reason for this - this is the real Greenhouse Effect, which has nothing to do with 'climate change'.

Lola said...

OTOH. So comparing a blunt nosed re-entry capsule to Concorde. Concorde got hot and expanded as it flew. And it was very well streamlined. That indicates frictional heating. And also the Shuttle and its ceramic tiles. And I do agree that the capsules have a blunt nose but I thought that that was there to slow them down. And yes that would cause a pressure build up in front of the capsule - that being the whole point. But, I 'thought' it was the compressed (and heated) plus atmosphere rushing off the nose that made it hot?

This is a discussion piece, not an argument. :-)

Lola said...

MW Of course there is a 'greenhouse' effect. That's the whole point of the Lord installing an atmosphere for us. Without one we'd either fry or freeze.

FWIW My shed is a brilliant example of this. It's solid blockwork clad with feather edge board on battens with an air gap between the cladding and the blockwork.

It's warm in the winter and cool in the summer. i.e. the air gap acts as an insulator.

Lola said...

And, I have it in my mind that the optimum air gap for a double glazed sealed unit window is about 3/4" (19 mm) as over that you get a lot of convection currents within the unit which speed up the heat transfer and render the window less effective - this is the 'thermo-syphon' thing of which we previously spoke. Sort of.

ontheotherhand said...

HI Lola. Good points to discuss. Concorde cared about fuel efficiency, whereas a reentry vehicle wants to get rid of energy. One could reenter the atmosphere gently if one flew up with tonnes and tonnes of rocket fuel and slowed down to 1000mph or something, but it's cheaper to use the atmosphere as brakes. Yes there is friction on Concorde, but googling it I understand it was 127C at the nose and 91C at the tail, which shows a mix of heating reasons.

The shuttle came in at 40 degree angle of attack and banked left and right to bleed energy. There is a really fun video of how absolutely amazing the feat of landing a shuttle was https://www.youtube.com/watch?v=Jb4prVsXkZU At the end of the video it shows the skill of pilots landing this flying brick at 260mph.

Mark Wadsworth said...

L, maybe the Greenhouse Effect is as simple as that. But it agrees my observation that thicker atmosphere = bigger greenhouse effect. Key - it warms and it cools!

The Consensus insist that GHG can only warm and are at a loss to explain why day time temperatures are LOWER than they would be without the (real) Greenhouse Effect.

If only we had better data on Gas Giants (which would be about six feet above and to the right of my chart), and a planet somewhere between us and Venus with an atmosphere thinner than theirs but thicker than ours. The more data points the better in this game.

Lola said...

OTOH. Re the Shuttle. Also the Top Gear version....

Mark Wadsworth said...

OTOH, fair play to NASA, they only lost one shuttle on re-entry.

L, on which the exploding bolts failed to explode?