The long history of diagonal comparisons

Bayard in the comments linked to Eunice Newton Foote, the Forgotten Pioneer of the Greenhouse Effect:

In her brief study [in 1856], entitled Circumstances affecting the Heat of the Sun’s Rays, the amateur scientist described an experiment in which she exposed glass cylinders equipped with thermometers to the Sun and attached to a pump to draw air from one and compress it in the other.

Eunice compared the heating and cooling in the two cylinders. She observed, first, that the cylinder with the compressed air heated up more than the other in which the vacuum had been drawn. Second, that the heating was greater with moist air than with dry air.

Thirdly, and this was her great and almost fortuitous discovery—since she also experimented with hydrogen and oxygen—that the greatest degree of heating occurred when one of the cylinders was filled with carbonic acid gas: CO2.

OK, this experiment suggests that some gases warm up more than others when in bright sunlight. This illustrates quite a few interesting things about the properties of glass and various gases - mainly density and specific heat capacity of gases, which is why you get the same result with pure argon as with pure CO2 - but it does not in the slightest illustrate what they claim it illustrates. For clarity, Earth's atmosphere is approx. 1% argon and 0.04% CO2.

Here's an article which - inadvertently - makes the contradiction clear:

How can I see for myself that CO2 absorbs heat?

As an experiment that can be done in the home or the classroom, Smerdon recommends filling one soda bottle with CO2 (perhaps from a soda machine) and filling a second bottle with ambient air. “If you expose them both to a heat lamp, the CO2 bottle will warm up much more than the bottle with just ambient air,” he says.

Fine, it does just that. Now, what's the theory again?

Why does carbon dioxide let heat in, but not out?

Energy enters our atmosphere as visible light, whereas it tries to leave as infrared energy. In other words, “energy coming into our planet from the Sun arrives as one currency, and it leaves in another,” said Smerdon.

True.

CO2 molecules don’t really interact with sunlight’s wavelengths. Only after the Earth absorbs sunlight and reemits the energy as infrared waves can the CO2 and other greenhouse gases absorb the energy.

Woah! Just woah! The experiment shows that CO2 is warmed by SW radiation from the Sun (or heat lamp); then they say that CO2 isn't affected by SW radiation, it is only warmed up by LW radiation from the warmed surface ('traps heat')!

If they wanted to illustrate how CO2 is warmed by LW radiation from the surface (i.e. warmed more than N2, O2 or Ar), they should put their bottles - including one filled with argon as a control - in the shade, so that they are only affected by LW radiation from the surface. If the CO2 bottle reaches a higher temperature than the others, it would be persuasive. Only they know that this wouldn't happen and so would not support the theory... which is why they don't do it.

The Diagonal Comparisons that underpin 'Climate Science'

The very cornerstones of Climate Science are two Diagonal Comparisons.

[To give examples:

FAIR COMPARISON: women's current wages in the UK -vs- men's current wages for similar work. This means something. If there is a difference, it needs explaining and maybe action needs to be take to level up.

DIAGONAL COMPARISON: nominal women office workers' wages in 1982, not adjusted for inflation -vs- Premier League footballer wages in 2022. That would be a Diagonal Comparison and of no relevance to anything.

You have to measure and calculate things as accurately as you can and then compare like-with-like i.e. changing only one variable, or as few as possible.]

Unfortunately for me, you have to be well versed in the Climate Science belief system (which I am) to know what I am talking about. And most of the well versed are of course Believers who just believe it all; the Sceptics mainly quibble about the finer details and don't look at the very foundations of the belief system. I can but do my best...
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Here goes. From RealClimate.org ("Climate Science from Climate Scientists...").

Diagonal Comparison #1

33 ºC is the difference between the mean surface air temperature of the planet and the blackbody radiating temperature (i.e. the temperature a blackbody would need to radiate at to be in equilibrium with the incoming solar radiation given an albedo of about 0.3) ["effective temperature"]. So far so good.

They define the true meaning of "effective temperature" in parentheses and correctly calculate Earth's effective temperature at 255K. What they do not mention is that this a hypothetical value only! It is only a very rough indicator of the actual temperature of "the surface" (cloud cover and that part of the sea and land that is cloud-free)*. You have to make several adjustments to work out the likely actual temperature.

They pretend however that 255K is a reliable indicator. They then compare 255K with the measured temperature of one part of "the surface" (at sea level) which is 288K. Hey presto, 33 degrees of Greenhouse Effect!

The 255K calculation, while correct in an abstract sense, is wildly inappropriate as a basis for comparison. Unless you are prepared to make on one or more of the assumptions that:
- clouds, sea and land have 100% emissivity. This is the biggest one, the overall weighted average is more like 80% emissivity, which would get adjusted effective temp. up to about 270K (reducing the 33 degrees by half). That's why they refer obliquely to 'blackbody' (which means 100% emissivity) instead of saying "assuming 100% emissivity", which would have people asking "Why assume anything? Why not use actual emissivity if it's relevant?", and/or
- clouds are at sea level, and/or
- clouds, sea and land are all the same temperature, and/or
- clouds, sea and land are all a uniform pale blue colour with albedo 0.3, and/or
- clouds don't exist (even though their existence reduces albedo and hence reduces effective temp), and/or
- there is no lapse rate, and/or
- without 'greenhouse gases' there would be no lapse rate, and/or
- without 'greenhouse gases' there would be less cloud cover and/or cloud altitude would be lower.
None of those assumptions is in any way correct, they are all reality-denying nonsense.

The obvious flaw with the 255K vs 288K comparison is that it not comparing like-with-like. Effective temperature is based on "what does the planet look like from space?". What you see from space is two-thirds clouds with patches of cloud-free sea or land. So when you calculate effective temperature, you are estimating the weighted average temperature of "what you can see from space", which is clouds and cloud-free sea and land.

The bulk of sea and land which are beneath clouds most of the time are irrelevant here, they could be pitch-black in colour with zero albedo - that wouldn't affect albedo as seen from space so doesn't affect our spaceman's calculation of effective temperature. Similarly, our spaceman can't tell through his telescope whether the white patches are clouds (low emissivity; unknown altitude) or snow fields (high emissivity) so he knows that his calculation of a planet's effective temperature is only a rough guide to its actual temperature.

The sea surface and land are of course warmer than clouds, because clouds are higher up. So what the Climate Scientists are really saying is "a warm thing is warmer than the average of the warm thing and some cold things, especially if you calculate the average using the wrong method." which is meaningless and irrelevant.

In the table at the end of this post, I refer to the effective temperature calculated the wrong way as B, line 28. Measured sea level temperature is A, line 288.
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This is NOT how you work out 'effective temperature' (if you want to get a meaningful answer). What you do is: take emissivity and topography/altitude into account of all the constituent parts (and ignore sea and land that is below clouds - there is separate more or less closed cycle for this) of "the surface"* and work out what temperature all the constituent parts of "the surface" would have to be to emit as much LW radiation to space as they, in total, absorb from the Sun.

This calculation is a bit tricky, but it's easy enough working backwards from actual temperatures and emissivity of the constituent parts of "the surface"* to see if you get the 'right' amount of outgoing LW. This is the the scientific way. You find that clouds, sea and land are at the required temperature/altitude emit, overall and on average, the right amount of LW (E, line 35 - this is the same as absorbed incoming solar radiation, C, line 22).

So there is no discrepancy between actual temperatures and effective temperature, if you calculate effective temperature correctly and make a fair comparison, like-with-like. There is no 33 degree difference to explain away; it's not even 8 degrees, it is +/- nothing. Sea/land surface has to be warmer than expected to emit more LW than first expected to compensate for the fact that clouds are as warm as expected (257K, line 5 vs 255K, line 28) BUT have low emissivity and so emit less LW than first expected. The overs and unders cancel out. So when our spaceman lands and finds that the sea level surface of the planet is warmer or colder than he calculated from afar, he is not too surprised.

Diagonal Comparison #2

While that is one way to assess the strength of the basic greenhouse effect, another one is measure the amount of long wave radiation from the surface that is absorbed in the atmosphere (by greenhouse gases incl. water vapour, clouds, aerosols, etc.). That is currently about 150 W/m2 and would be zero with no greenhouse effect at all.

They are comparing upwelling LW from sea and land, assuming 100% emissivity (D, line 33 = 390 W/m2) with C, line 22, 240 W/m2. There is, unsurprisingly, a 150 W/m2 difference. They say "Look! GHG's are trapping or blocking 40% of outgoing LW. This is what is heating the planet.". To be fair to this lot, they do mention clouds, which are actually responsible for all the absorbing they try to blame on 'Greenhouse Gases'.

Two-thirds of that hypothetical 390 W/m2 LW emitted at sea level (D, line 33 - they should be using 367 W/m2 at line 34, but hey) hits the underside of clouds and is either absorbed by the clouds or reflected back down. What gets to space is the weighted average of what clouds emit upwards and what the cloud-free sea or land emits (E, line 35), which is exactly the same as incoming solar (C, line 22)*.

So again, this is like saying "a warm thing emits more LW than the average LW emitted by the warm thing and some cold things, especially if you overstate the LW emitted by the warm thing and ignore the existence of the cold things" i.e. meaningless and irrelevant.
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* I put an asterisk after "the surface" as this is a very important concept. Imagine a freshly made sponge cake, still warm from the oven that has just had some icing applied (I think you are supposed to let the sponge cool down first, but I'm in a hurry... to find an analogy). The main sponge part = sea or land. Two-thirds of the cake's surface is covered in icing = the clouds. "The surface" of the Earth cake is two-thirds icing and one-third exposed sponge. Whatever heat exchange there is between the sponge and icing is irrelevant as far as the outside world (space) is concerned. For the cake to cool down, all that matters is the LW which is emitted by the exposed (non-iced) sponge and the icing. Including the LW radiation hypothetically emitted by the covered part of the sponge is insane and insanely stupid.

On Venus, the high temperature of the sponge (hard surface) is irrelevant as it is all covered with a thick layer of icing (clouds). The temperature of the upper parts of the clouds is pretty much the same as the calculated effective temperature. There is a separate set of rultes to reconcile temperatures as between hard surface and clouds and there is no 'Greenhouse effect', let alone a 'runaway Greenhouse Effect' on Venus. On Mars, there is barely any icing (a few low altitude dust clouds) so although there is more CO2 per m2 on Mars than there is water vapour and CO2 added together on Earth, there is little or no Greenhouse Effect on Mars.
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Here is my list of assumptions and summary workings in case anybody want to check. This is all the coherent bits of actual information and proper phsyics that I have pieced together from blogs and articles by 'Climate Scientists'. They can't deny that they have said all this, although they do when it suits them.

Click to enlarge/read more clearly.

Let's see if Harry Dale Huffman's approach works with Titan

Titan is my new favourite moon/planet. It orbits Saturn, is a bit bigger than our Moon, and has an atmosphere that is strikingly similar to Earth's - it's mainly N2, with 5.65% CH4 to spice things up -  with a surface pressure 1.48 times as much as Earth's surface pressure.

Harry Dale Huffman pointed out that comparing the surface temperatures of Venus with the surface temperature of Earth 288K is a diagonal comparison. Venus' surface temperature is ~737K, largely because atmospheric pressure is 92.1 times as much as on Earth. A direct comparison is the temperature of Venus' atmosphere at the altitude where atmospheric pressure happens to be equal to Earth's surface pressure versus Earth's surface temperature, so we compare 338K with 288K.

Then you just adjust Venus' temperature down to compensate for the fact it is nearer the Sun and the solar radiation it gets is more intense. The adjustment factor is the fourth root of (2,601 W/m2 ÷ 1,361 W/m2) = 1.91 ^ 0.25 = 1.176*. Divide 338K by 1.176 = 287.4K, that's as close to 288K as makes no difference, job's a good 'un.

HDH does not claim to be able to explain why this is so (see discussion here), but that's just how science works. First step is observe stuff, recognise clear patterns, and then you try and work out why. His guess appears to be that you can ignore a planet's albedo when looking at temperatures, because higher temperature causes clouds; clouds increase the albedo; thus reducing incoming solar radiation; which would reduce the temperature. So we would end up in a circular calculation. Or something like that.
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OK, let's strap on our space suits, fire up the rockets and head off to Titan. Temperature at the surface is measured/estimated to be 93.7K. It receives 14.8 W/m2 solar radiation (same as Saturn, but knock off 0.8% because it is in Saturn's shadow 0.8% of the time and add on 0.08 W/m2 which Titan receives from Saturn itself).

Let's adjust Earth's surface temp (288K) down using the same method as above: 288K x ((1,361 W/m2 ÷ 14.8 W/m2)^0.25) = 93K. That's pretty close to 93.7K!

However... HDH's direct comparison method is the temperature on Titan at the altitude where pressure = Earth's surface pressure versus Earth's surface temperature, which happens to be at ~8 km. With a lapse rate of ~0.5 K/km, the temperature there is ~89.7K, against our predicted 93K. So it's ~3 degrees cooler than predicted by HDH's approach, which is still close enough, I think.

Which all demonstrates that a planet's albedo and the precise composition of its atmosphere are probably irrelevant, and whether or not the constituent gases can 'trap' radiation is almost certainly less than irrelevant.
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* The short cut is divide distances from the Sun and take the square root = (149.6m km ÷ 108.2m km) ^ 0.25 = 1.176.

AGW theory is based on two blatant 'diagonal comparisons' (Part 2)

In Part 1 I showed how they use a sneaky 'diagonal comparison' (i.e. they don't compare like-with-like) to create the illusion that Earth is warmer than it should be.  Part 1 covers the balance between Earth's system and the Sun/outer space.

Then there's what goes in within the Earth's system itself. The other sneaky thing they do is to say that the atmosphere is far warmer than it is, it's just a straight lie. From NASA's Earth Factsheet:

Terrestrial Atmosphere
Surface pressure: 1014 mb
Surface density: 1.217 kg/m3
Scale height: 8.5 km
Total mass of atmosphere: 5.1 x 1018 kg
Total mass of hydrosphere: 1.4 x 1021 kg
Average temperature: 288 K (15 C)

Say what?

Imagine you are asked to measure the average temperature of the water in a deep lake. If you just take the surface temperature, you might get ~288K. But that's not the average temperature of the all the water in the lake. By and large it gets colder as you go down, so the true average is much lower.

The reverse applies in the troposphere (the lowest ~11km of the atmosphere). This is the bit we are interested. It's where the weather happens and the layer which warms and cools the surface.

It gets cooler as you go up, so if you only measure the temperature in the warmest layer, at or slightly above sea-level (where most measuring stations are), you will get an artificially high average temperature (i.e. ~288K).

~288K is fair estimate of the average surface temperature, but that's something completely different to the average temperature of the air in the troposphere. That's a lot colder. If you take a fair sample of readings at all altitudes, you would get ~255K, which is not uncoincidentally the temperature we expect from looking at the Earth vs Sun/outer space balance. See also Climatologists are Flat Earthers.

The vertical temperature gradient is no mystery. Basic maths, a rudimentary understanding of the Gas Laws and common sense (principles and worked example) tell us that it must be warmer than the ~255K average at sea level and colder than the ~255K average at the top of the tropopause. They worked this out in the 19th century and it was part of normal physics textbooks until a few decades ago. There's a given amount of thermal energy, and gravity and the Gas Laws constantly recycle it downwards.

The precise temperature gradient (aka 'lapse rate') is primarily the trade off between thermal energy (temperature) and potential energy (altitude). We all know that warm air cools as it rises. Energy cannot be created or destroyed, so what happens to the 'lost' thermal energy? Easy - air loses thermal energy as it rises... and gains potential energy. The reverse happens with Chinook and Föhn winds (Föhn is German word, pronounced 'fern' and is also the name for a hand-held hair dryer), when falling air warms up. So the lapse rate = gravity ÷ the specific heat capacity of 'air'.

(The lapse rate is reduced by the latent heat of evaporation, which has the opposite effect. The surface is cooled when water evaporates, the latent heat manifests itself again higher up when water vapour condenses. The latent heat in one gram of water vapour is enough to warm a cubic metre of air by about 2 degrees, it's a lot.)
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The AGW theorists make great play of the fact that Earth's surface (being ~288K, not ~255K) radiates ~390 W/m2 but only ~240 W/m2 gets to space. They claim that the missing ~150 W/m2 is trapped by 'greenhouse gases'. This is part of Diagonal Comparison #1. Two-thirds of the surface doesn't radiate directly to space because it's covered by clouds; some of the surface radiation is reflected back down (in a quite literal sense, like clouds reflecting visible light) and the clouds themselves emit the required ~165 W/m2 to space. The average emitted to space ≈ 240 W/m2, which is what Earth receives from the Sun.

The AGW steamroller never stops of course. For sure clouds reflect some infrared radiation back down (which is why a cloudy night is warmer than a clear night), but clouds don't 'trap' radiation or warm the surface overall; on the whole, it's cooler if it's cloudy (there's no 'positive feedback'). And clouds certainly do not warm the atmosphere overall, the extra warmth under a cloud is equal and opposite to the missing warmth above it.

Radiation isn't pollution like plastic in the oceans, it can transform into other forms of energy instantaneously. Trying to account for it is like trying to catch sunshine in your hands. You cannot add, subtract, multiply 'radiations', the maths is insane but entirely unnecessary to explain and understand the basic equilibrium position with temperatures etc. You need to bring in radiation to reconcile the warming effect of Ozone Depletion, but that's another story...

AGW theory is based on two blatant 'diagonal comparisons' (Part 1)

The theory goes as follows:
1. Earth is 33 degrees warmer than it should be based in incoming solar radiation alone;
2. This is due to 'greenhouse gases' and 'trapped radiation';
3. Hence more greenhouse gases = higher temperatures.

Item 1. is based on the most outrageous Diagonal Comparison of all time. If this is not a valid comparison, then we need not concern ourselves with whether 2 and 3 are valid*.

The Hansen approach is:
1. Calculate the average effective (i.e. expected) temperature** of clouds, land and ocean surface. He just calculates one overall average temperature based on weighted average albedo (reflectiveness) of clouds, land and ocean surface, which is pretty close to the weighted average expected temperature of clouds, land and oceans separately. The key here is that land and ocean surface below clouds are ignored when calculating this expected temperature.
2. Compare that with the actual temperature of land and ocean surface... completely ignoring the actual lower temperatures of clouds.

A proper scientific comparison compares like with like!

So if you calculate the effective temperature of clouds, land and ocean surface (ignoring land and oceans below clouds), you have to compare it with the actual temperature of clouds, land and ocean surface (ignoring the land and ocean surface below clouds)... and you end up with a 'Greenhouse Effect' of +/- zero, zilch, nothing. Here are the numbers. (Cloud top altitude in pale blue as that is my best estimate and the variable most worthy of research or debate).

It all matches up nicely. Actual temperature ≈ expected temperature and outgoing infrared radiation ≈ incoming solar radiation. There is no 'missing radiation' or 'trapped radiation':
References:
Tutorial on the Greenhouse Effect, this explains how it is calculated.
How high in the sky are clouds?
Scientists detect world's coldest cloud hovering over Pacific Ocean
What is Earth’s surface emissivity?

* The real explanation for the apparent 33 degree difference is far simpler. The most plausible reason for the recent slight increase in temperatures is Ozone Depletion, but these have been crowded out. Whether you understand or agree with these is irrelevant to the question of whether there is any evidence for 'greenhouse gases' causing 33 degrees of warming in the first place.

** Effective Temperature is the hypothetical temperature that a planet would have to be to emit as much radiation as it receives from its star, assuming 100% emissivity. But it is a good first approximation for the actual temperature for a fast-spinning planning planet with a thick atmosphere, like Earth.
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The other Diagonal Comparison is that the official average surface temperature is NOT representative of average troposphere temperature, which is what we are interested in. Surface temperature measurements are 33 degrees warmer than the average temperature of the troposphere because measurements are weighted towards very low altitudes. This would not be so if Earth were covered with very high mountains. I'll cover that in Part 2, and then I'm done with this nonsense.

The Diagonal Comparison that underpins 'climate science'

I am aware that I am losing my audience here, but I'm drafting chapters for a book that will never be published. I trust you are familiar with the various concepts and calculations by now, it's a bit tedious repeating them all.
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In science, as in real life, you are supposed to compare like-with-like.

If you run experiments to see how high a ball bearing will bounce, you are only supposed to change one variable, so...
a) You drop a ball bearing, from the same height, onto different surfaces (concrete, rubber, wood); or
b) You drop the same ball bearing, onto the same surface, from different heights; or
c) You drop a different size ball bearing (made of the same material as the small one) from the same height onto the same surface.

The results tell you
a) How bouncy different surfaces are; or
b) How the drop height affects bounce height; or
c) How size of the ball bearing affects bounce height.

There is no point dropping  a small ball bearing, made of steel, from 10 metres, onto concrete, and measuring how high it bounces. Then dropping a large ball bearing, made of copper, from 12 metres, onto rubber, and measuring how high that one bounces. The latter will bounce a bit higher, we assume.

But what conclusion can you draw? That large ball bearings bounce higher than small ones? That copper is bouncier than steel? That a ball bearing bounces higher if you drop it from higher? That rubber is bouncier than concrete? At least one of those things must be true, but some might not be.

Clear so far? Back to the actual topic...
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Q1. What is the Consensus' most compelling evidence for the influence of 'greenhouse gases' on the temperature of the hard surface?

A1. The poster boy (or girl?) for this is the planet Venus.

A few agreed facts:
- if you look at it through a visible-light-telescope, you can see that the surface is white (clouds made of H2SO4*, although we don't know that yet), with an albedo 0.75. If you are Isaac Newton, you can also work out its distance from the Sun, its size and its mass (and hence acceleration due to gravity).
- the 'effective temperature' can then be calculated as ~ 230 K (this calculation is really tricky, but let's accept the result as correct).
- with infra-red-telescopes and actual space probes, we have since measured the actual temperature at the hard surface at 735 K, and know that the atmosphere is 95% CO2. There are about one thousand tonnes of CO2 per m2 surface (as opposed to about 6 kg per m2 on Earth).
- therefore, the Greenhouse Effect on Venus ≈ 500 K (on Earth, the same calculation suggests ~ 33 K).

So far so good, no problems there. You know the 'effective temperature'; how high the visible clouds are (50 km - 80 km. let's take the mid-point to be the 'effective surface' = 65 km); what the main gas in the thick atmosphere is and its specific heat capacity etc. You can then work out likely lapse rate (8.87 m/s2 ÷ 1,126 J/K/kg** = 7.8 K/km) and estimate the likely surface temperature by simply adding lapse rate x altitude (~ 7.8 K/km x ~ 65 km ≈ 500 K) to temperature of 'effective surface' (~ 230 K) ≈ 730 K. Bingo!

But the Consensus skips the basic physics, logic and maths and jumps to "It was the one thousand tonnes of CO2 wot dunnit!"

Q2. Why is this a Diagonal Comparison?

A2. Because they are not comparing like-with-like. They calculate the 'effective temperature' of the clouds and then compare it with the temperature of the hard surface. Of course the hard surface is a lot hotter - because it's much lower down than the clouds (which form the basis of our calculation of 'effective temperature') and there's a lapse rate (temperatures go up as you descend from the clouds). You might as well calculate how high our ball bearing will bounce if you drop it from 10 metres; then drop it from 5 metres anyway and be surprised that the observation does not match the prediction.

What if it turned out that Venus is actually a pale grey planet with only a thin layer of white clouds? Our calculation of the 'effective temperature' (based on what you see through a visible-light-telescope) is the same, but this doesn't need much adjustment for lapse rate x altitude to estimate the temperature at the hard surface.

Hey presto, Greenhouse Effect nearly vanished - like on Mars. Mars serves as a good counter-example. It has hardly any clouds, so the 'effective surface' for which 'effective temperature' (based on low albedo of soil = 0.25 i.e. dark red-grey) is calculated is pretty much at the hard surface. That is why there little apparent discrepancy between 'effective temperature' and hard surface temperature and using the Consensus approach, the Greenhouse Effect is only 6 K. The approach is deeply flawed anyway - see A4. below.

Q3. "Hah!" shouts the Consensus, "So you admit that if there were less CO2, the [hard] surface temperature would be lower? So we are correct - less CO2 => lower temperatures; more CO2 => higher temperatures. So CO2 must be a Greenhouse Gas!!"

A3. Sure, if we just remove a lot of the CO2, the temperature at the hard surface would be lower. The thicker the atmosphere, the greater the Greenhouse Effect and vice versa. But if we replaced the CO2 with the same amount of N2 or O2, the temperature of the hard surface would go up a bit (I think), because the specific heat capacity of those gases is lower than for CO2 so the lapse rate would be higher.

Also, saying "So you admit..." is pure polemic and of no relevance to a scientific discussion. And, if you want cheap shots, there is twenty-five times as much CO2 per m2 on Mars than there is on Earth but officially barely any Greenhouse Effect.

Q4. Isn't it a lazy and logically flawed short-cut to compare 'effective temperature' with hard surface temperature in order to estimate magnitude of the Greenhouse Effect anyway?

A4. Yes, good question and I'm glad you asked.

Let's imagine Venus had no clouds whatsoever, and let's assume that like on Earth, the surface temperature goes up 'a bit' as a result.

We then re-calculate 'effective temperature' based on an albedo of (say) 0.25 (dark) instead of 0.75 (nearly white), which means about three times as much solar radiation being absorbed and converted to kinetic energy (heat); which means the 'effective temperature' you calculate will be a lot higher. So the apparent discrepancy between 'effective temperature' and hard surface temperature will be approximately halved (I haven't done the exact number yet).

Does that mean that the very real Greenhouse Effect has halved (or whatever the exact number is)? Of course not - lack of clouds means the temperatures go up, so there's now slightly more Greenhouse Effect!

The reverse logic applies to Mars which has hardly any clouds and so no apparent Greenhouse Effect (using the flawed Consensus approach to calculating it). Nonetheless, Mars has a predicted lapse rate of about 5 K/km (3.71 m/s2 ÷ 736 J/K/kg - the measured value is half that, apparently). But if it did have a layer of clouds at 10 km altitude (I'm not sure if that's physically possible, but let me illustrate the point) it would have an albedo of 0.75 (like Venus); Mars would only absorb one-third as much solar radiation; and the 'effective temperature' we calculate would fall from 209 K to 159 K ((0.333 ^ 0.25) x 209 K).

So - using my method - we would estimate the hard surface temperature on cloudy Mars to be 158 K plus 10 km x 5 K/km = 209 K. This is a bit less than the measured hard surface temperature of 215 K, which makes sense as the clouds would cool it down a bit.

So now, even though the hard surface temperature of Mars has gone down 'a bit' (and the actual Greenhouse Effect has gone down 'a bit' as well), the apparent Greenhouse Effect would go up from 6 K to 50 K! Even though in reality, not much has changed, which means all these figures - 500 K for Venus, 33 K for Earth and 6 K for Mars are meaningless.

* "Poor Jones is dead and gone,
his face will be no more.
For what he thought was H2O
was H2SO4"

** Actually, this is a slightly circular calculation. You would start by assuming the highest layer below the clouds is ~ 230 K, and the specific heat capacity of CO2 at that temperature is lower (0.763 J/K/kg) so you would predict a higher lapse rate of 11 K/km; so you would have to work your way down, km by km and use a different lapse rate each time until you're down at the surface; then work back upwards again until it is all in balance.

President Erdogan does a glorious diagonal comparison.

From City AM:

US President Donald Trump has taken a hard line against Turkey over the fate of American pastor Andrew Brunson, who has been detained in Turkey for the last two years, accused of links to the banned Kurdistan Workers Party (PKK) and the Gulenist movement which has faced a crackdown after a failed coup in 2016...

In a New York Times article at the weekend Erdogan threatened that NATO-member Turkey could “start looking for new friends and allies” if the US did not reverse its trend of “unilateralism and disrespect”. Turkey also wants the US to hand over Pennsylvania preacher Fethullah Gulen which it blames for the 2016 coup attempt.

Woah! That's not how prisoner exchanges work.

Brunson is an American held in Turkey against his will; he wants to go back to America.

Gulen is a Turk in exile in America very much under his own will; he does not want to back to Turkey.

Diagonal comparisons: Corbyn edition

From City AM Forum:

One part of Labour’s economic offer which really did strike a chord with the electorate was the promise to nationalise industries such as rail and water. To anyone with direct experience of the old British Rail or the Post Office (which made you wait six months to get a phone installed) this almost defies belief. But only those over 55 can remember...

What on earth do rail and water companies have to do with installing telephones? Corbyn might possibly have said re-nationalise the Post Office, this is now a quite distinct body to BT, the one which does the telephones and competes on a pretty level playing field with lots of private businesses. As anybody under 55 understands perfectly well.

(Both Corbyn and May both accused mobile phone companies of market abuse or something IIRC, which seems a bit off piste to me, they do a great job all in all. It's the internet providers who insist you pay top dollar for a landline you will hardly use if you want broadband who are taking the piss).

Prior to rail privatisation just after the 1992 election, the peak number of passenger journeys made each year was some 1.1bn in the mid-1950s. Faced with rapidly rising road competition, the rail industry saw journeys fall steadily, to a trough of around 750m in the mid-1990s.

After privatisation, massive investment programmes have been carried out and, in the form of the train operating companies, there is now a distinct part of the industry whose priority is the consumer. Journey numbers rose, passing the 1bn mark in 2003, to the current level of 1.7bn, a figure not seen since the early 1920s, when road competition was weak.

So the revealed preference of consumers seems to be that they rather like the current structure. They actively choose to use rail in massive numbers.

We've done that one. Yes, the number of passenger journeys on private rail has doubled in the last twenty years - but so has the number of journeys on the government-run, union-controlled, highly regulated etc London Underground network, so that proves nothing. Rail passengers couldn't care less who owns it or runs it, they just want a reliable service.

Muddled argument for contributory benefits

Ryan Bourne writes a largely sensible article about immigration in City AM, marred by this diagonal comparison:

Indeed, the cost of immigration quotas can be seen with a simple example. Suppose an entrepreneur wanted to come to the UK and had the potential to build a business worth billions. Ludicrously, if he was number 100,001 that year, he’d be kept out.

That is the crassest diagonal comparison I have heard for ages and has no place in a sensible discussion. You could counter it with some nonsense like this:

Indeed, the benefit of immigration quotas can be seen with a simple example. Suppose an violent extremist wanted to come to the UK and had the potential to blow up a building worth billions. Conveniently, if he was number 100,001 that year, he’d be kept out.

There is a killer argument against Citizen's Income that says welfare payments should be contributory, i.e. you can only claim unemployment benefit if you have been working and paying tax for a minimum period and then are made redundant. This is economic nonsense but has a lot of political appeal. Worse still, it is cancelled out by the equal and opposite notion that welfare payments should be means tested, which is also economic nonsense with a lot of political appeal. (I suppose means-testing in turn is largely cancelled out by tax breaks for 'savings' which are also economic nonsense with a lot of political appeal...).

Anyway, returning to the article...

Ideally, this would mean lowering barriers to migration as broadly as possible but making the UK’s welfare system more contributory to avoid any welfare draw factors.

Complete bollocks.

Outside the EU, we can merrily restrict welfare payments to UK-resident British Citizens only (including or excluding immigrants who have been naturalised) or to those who have lived (or indeed worked) here legally for a set number of years, or make up any other conditions that keep the electorate happy. This test can be applied to non-contributory/universal benefits like a Citizen's Income, the right to vote or to use the NHS 'for free' etc.  just as much as it can be to contributory benefits.