Friday 28 May 2021

A painted clock is right twice a day

I've just stumbled across this classic in The Guardian from 2018:

Thirty years ago, James Hansen* testified to Congress about the dangers of human-caused climate change. In his testimony, Hansen showed the results of his 1988 study using a climate model to project future global warming under three possible scenarios, ranging from ‘business as usual’ heavy pollution in his Scenario A to ‘draconian emissions cuts’ in Scenario C, with a moderate Scenario B in between.

Changes in the human effects that influence Earth’s global energy imbalance (a.k.a. ‘anthropogenic radiative forcings’) have in reality been closest to Hansen’s Scenario B, but about 20–30% weaker thanks to the success of the Montreal Protocol in phasing out chlorofluorocarbons (CFCs)**.

Hansen’s climate model projected that under Scenario B, global surface air temperatures would warm about 0.84°C between 1988 and 2017. But with a global energy imbalance 20–30% lower, it would have predicted a global surface warming closer to 0.6–0.7°C by this year. The actual 1988–2017 temperature increase was about 0.6°C. Hansen’s 1988 global climate model was almost spot-on.


Classic lack of self-awareness there. The outcome was somewhere vaguely near his mid-estimate, and presumably miles off his lower- and upper-estimates. That's hardly "spot-on", is it?

** The Montreal Protocol was indeed successful in reducing CFC production, hooray. But the pre-existing CFCs are still working their way through the system and are still causing most or all of the current slight warming, reducing the impact of CO2 down to zero.

* James Hansen is the one who came up with the trick of calculating the effective temperature of Earth assuming two-thirds cloud cover, and then contrasting that (low) temperature with with the actual temperature of land/ocean surface (warmer) and ignoring the actual temperature of clouds (colder). See top of third column on page 1 here. He dresses it up in scientific language to cover his traces.

If you include the actual temperature of clouds when calculating the overall actual temperature, it would bring it down to pretty much the same as the effective temperature, i.e. if he had done an honest comparison, like-with-like, he would have had no evidence for a CO2-caused Greenhouse Effect whatsover.

24 comments:

Dinero said...

He is not saying that the temperature of the surface radiating to space is 288 K.

He is saying the effective temperature for albedo adjusted solar flux at the surface is 255 . But we find a higher temperature 288. Why is that. The answer is the greenhouse effect.

Mark Wadsworth said...

Din, the point is he is not comparing like-with-like. Do you not understand that?

"albedo adjusted" means his 255K is the average effective temp of clouds (cold), land (warm) and ocean (warm). Fine, that's probably accurate.

But 255K is not the expected actual temperature of the 'surface' i.e. land and oceans. 255K is the expected average temperature of land and oceans AND CLOUDS.

Now, what is the average ACTUAL temperature of land, ocean AND CLOUDS?

Why, it's ~255K of course!

Dinero said...

The expected temperature for the land/oceans for that amount of solar flux adjusted for cloud cover is 255 K . But the actual is 288K.

Mark Wadsworth said...

Din,

Please do your homework!

Your trot out the same basic lie that underpins Alarmism:

"The expected temperature for the land/oceans for that amount of solar flux adjusted for cloud cover is 255 K"

Bollocks.

In truth, the expected temperature or land/oceans AND CLOUDS is 255K.

Can you see the key words "AND CLOUDS"???

Dinero said...

It does not have to include clouds. I think anyone reading that paper would take it to mean that there is a Flux on the land/ocean and a temp for the land/ocean from StefB can be calculated from that.

I see what you have in mind , no need to repeat yourself. You are thinking of the word Albedo and one object. Hansen is treating the Land/ocean as the object and the clouds as a blocker. If you want to point out the average from including clouds, that is a different subject and it does not always work, eg if flux is blocked to an object by a second object that absorbs. then the average of the temps across the two objects is the same as before, but if the second object is reflective then the average is lower.
You already acknowledged in the comments on the HDH post that satellites record that there is less flux leaving the atmosphere than emitted from the land/oceans. So I don't see what you are pursuing further.
As for the atmospheric temp in the PV=nRT post. The calculation follows the graph because you used the actual measured density and temp from the same data set as the graph and so of course it does.
Venus and Titan , consider that they both have particularly dense atmospheres and so that pushes the 1 Bar level up where it is cooler.

Mark Wadsworth said...

Din, read what your write:

"You already acknowledged in the comments on the HDH post that satellites record that there is less flux leaving the atmosphere than emitted from the land/oceans."

Yes, those are facts. I don't argue with facts.

What the satellites measure is the AVERAGE radiation being emitted upwards by a combination of clouds (cool, hence lower radiation) and land/oceans (warmer, hence higher radiation).

So of course the AVERAGE radiation going to space is less than that emitted by land/oceans in isolation. You can't expect the surface radiation to punch through clouds unaffected.

"As for the atmospheric temp in the PV=nRT post. The calculation follows the graph because you used the actual measured density and temp from the same data set as the graph and so of course it does."

To summarise - real life and theory match up nicely. Do you have a problem with that?

Dinero said...

No problem with that . As I wrote of course they match.

The greenhouse effect is that less flux leaves the atmosphere than is emitted from the land oceans. So as you acknowledge less flux leaves the atmosphere than is emitted from the land/oceans because it is blocked / reflected on the way up by clouds, then you therefore acknowledge the greenhouse effect exists.

Mark Wadsworth said...

Din: " So as you acknowledge less flux leaves the atmosphere than is emitted from the land/oceans because it is blocked / reflected on the way up by clouds.."

For sure.

"... you therefore acknowledge the greenhouse effect exists. the greenhouse effect exists"

Nope. The Greenhouse Effect says that minuscule amounts of traces gases can warm the atmosphere. This is based on a diagonal comparison as I explained above, so if that's all the evidence they've got, they've got no evidence at all.

Clouds cool the surface, they don't warm it.

As a separate topic, there is a very real Gravito-Thermal Effect which you refuse to acknowledge, despite it is sub-GCSE level physics.

Mark Wadsworth said...

Din: "Venus and Titan , consider that they both have particularly dense atmospheres and so that pushes the 1 Bar level up where it is cooler"

Here we go again. Cooler than what? When doing comparisons, you have to say what you are comparing with what. FFS.

So sometimes you accept the existence of the Gravito-Thermal Effect and sometimes you don't?

Dinero said...

No the Greenhouse effect is not trace gases
see the Hansen paper Quote , Clouds third column Second paragraph.

"The mean surface temperature is Ts -288 K. The excess, Ts -T0, is the greenhouse effect of gases and clouds,.."

And as you know objects that absorb emit the same and so the clouds absorb and emit thus warming the land /ocean and they reflect warming the land ocean.

Mark Wadsworth said...

Din, it's still a massive lie. Don't you get it?

1. There is no excess, if you compare like with like.
2. Clouds (and water vapour vapour) cool things down, by about 10 degrees (guess).
3. CO2 has no effect (or at least, no evidence has ever been presented).
4. There is a Gravito-Thermal Effect, which is the correct (and older) explanation. It explains so much more than this cockamamie back of a fag packet waffle about 'radiation'.

Bayard said...

"three possible scenarios, ranging from ‘business as usual’ heavy pollution in his Scenario A to ‘draconian emissions cuts’ in Scenario C, with a moderate Scenario B in between."

Without having access to the actual paper, it is impossible to tell whether the "heavy pollution" mentioned is traditional pollution, i.e. things in the atmosphere that ought not to be there, or new pollution, i.e. GHGs. CFCs are traditional pollution and not GHGs, so it looks like Hansen has lumped them in for good measure, possibly becasue he realised their contribution to global warming. However, it's just confusing the issue.

Bayard said...

"The actual 1988–2017 temperature increase was about 0.6°C. Hansen’s 1988 global climate model was almost spot-on."

This is why climate "science" isn't science. The business of science is, via the scientific method, to examine data, formulate theories to explain the observed phenomena, then carry out experiments to try to disprove the theories. Climate "science", on the other hand, formulated a single theory and ever since has been carrying out experiments and constructing models to try to prove it. This is the wrong way round, as Sir Arthur Conan Doyle put it:"It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts."

Dinero said...
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Dinero said...

The Gravito Thermal effect.
The Heat caused by Gravity, accelerating air molecules, subsided by radiation into space billions of years ago. What we have now is molecules slowed down on the way up and sped up on the way down. But there is no heat source added by gravity now to increase the land/ocean temperature above the effective temperature.

Mark Wadsworth said...

B, pollution is whatever they want it to be. And agreed.

Din: "there is not heat source"

The heat source is the Sun. This warms the atmosphere to average 255K. The Gravito-Thermal Effect recycles this downwards, so the top half is cooler than 255K and the bottom half is warmer than 255K.

Do you not even understand the basics?

While gravity is clearly not thermal energy, it is still 'energy', namely 'potential energy'.

Dinero said...
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Dinero said...
This comment has been removed by the author.
Dinero said...

On second thoughts I was a bit off the mark with "sped up on the way down" - air molecules do not fall out of the sky.

Mark quote "The Gravito-Thermal Effect recycles this downwards, so the top half is cooler than 255K and the bottom half is warmer than 255K."


Regardless of the mechanism that you have in mind for the redistribution it doesn't fit the bill of describing the atmosphere because it does not account for the extra heat in the atmosphere. There is an extra 150 wm2 measured by satellites ,accumulated in the ground , sea , cloud system, due to insulation,.

Mark Wadsworth said...

Din, GTE fits the bill perfectly. There is no 'extra heat'. What appears to be 'extra heat' is equal and opposite to 'missing heat' at altitudes above 5 or 6 km. The temp up there is LOWER than the effective temp.

And there is no 'extra 150 w/m2' and there is no 'missing radiation'. Those are more climate lies. What satellites measure is exactly what is emitted by cloud-free land/oceans and cloud-tops.

Would you expect radiation emitted by land/ocean that is covered in cloud to punch straight through the clouds unaffected? And then that same radiation being stopped in its tracks by a few CO2 molecules?

Sane and rational answers = "No" and "Irrelevant, as answer to first question was 'no', but also 'no'".

Alarmist answers "Yes" and "yes".

To cut a long story, clouds block radiation from ground. The Alarmists pretend the clouds don't exist and say that it is the CO2 blocking radiation from the ground.

Dinero said...

You know from StefanBoltzmann that the ground/oceans emit 390 Wm2. And you know form satelites that 240 wm2 is going to space. A redistribution mechanism cannot explain that. With just a redistribution mechanism the emission from the ground at 288k would reach space.

You say that it is blocked by clouds. Well therefore you acknowledge the green house gas effect exists beacause that is what the greenhouse effect is.

Mark Wadsworth said...

Din: "A redistribution mechanism cannot explain that"

No, and it doesn't seek to.

Ground level radiation is blocked/absorbed/reflected by clouds (which themselves emit much less, being colder, higher up and having < 100% emissivity).

"You say that it is blocked by clouds"

I don't 'say' it, it is just true.

"therefore you acknowledge the green house gas effect exists because that is what the greenhouse effect is"

You have repeated your incorrect statement of earlier.

The fact that clouds, being made of tons of water droplets (not water vapour!)block/absorb/reflect radiation IS NO EVIDENCE WHATSOEVER for the claim that trace amounts of CO2 have any effect on temperature.

And the 33 degrees is a diagonal comparison, it is not comparing like-with-like, and hence not evidence of, or of relevance to anything at all.

Bayard said...

Mark, unfortunately for precision, "vapour" can mean water in either its invisible, gaseous form or its visible, droplet form, as can "steam". However, whilst acknowledging that gaseous water is a "greenhouse gas", the Alarmists still manage to handwave away the corollary, which is that, given that water is several orders of magnitude more abundant in the atmosphere than CO2, why, if it has the same effect as CO2, are we even bothering with CO2?

Mark Wadsworth said...

B, bugger. H2O(g) then.

"water is several orders of magnitude more abundant in the atmosphere than CO2"

There is on average about twenty-five times as much H2O(g) as there is CO2.

Luckily that has no direct effect on temperatures either, only when it condenses and releases latent heat.