Wednesday, 17 February 2021

"My confusion and anger ended when our host showed me the real physics"

I did a bit of light trolling at Science of Doom and elicited this response:

You are confusing several topics.

No I'm not. They are confusing the issue, as he later confirms:

Elsewhere I have discussed why it is simplest to consider the steady-state balance or imbalance at the TOA [top of atmosphere]. An imbalance at the TOA is created by rising GHGs slowing down the rate of radiative cooling to space. DLR is an internal radiation flux that moves heat WITHIN our climate system and therefore isn’t important to the radiative imbalance at the TOA. A “rising effective emitting layer" is important to the balance at the TOA.

Since AGW is a very complicated subject, it is often explained with a variety of models paradigms including: Increasing DLR “warms” the surface, CO2 “traps” heat, CO2 acts as a blanket or insulation, GHG’s act as shell or layer around the Earth (Willis promotes a “Steel Greenhouse” Model) and a “rising effective emitting layer” model (promoted here and by Linden among others). IMO – and others probably do disagree – all of these models are flawed.

Which was exactly my point. Notice how he first says that the "'effective emitting layer' is important" and then says that the "'rising effective emitting layer' model [is] flawed". I have spent a year wading through these endless layers of crap:

When I first came here (on the advice of Steve McIntyre), I was continuously frustrated and intemperate, because I KNEW that doubling CO2 would double the number of photons emitted by CO2 and usually halve the distance they traveled between emission and absorption. I couldn’t see why doubling CO2 would change anything – which turns out to be an excellent first approximation to the truth. The reduction in radiative cooling [to] space from 2XCO2 is barely more than a 1% change despite doubling the emission of photons by CO2. (As best I can tell, the rising effective emitting layer model doesn’t take into account the doubled emission of photons by doubled CO2.)

Luckily, Salvation is at hand for those Who Know And Want To Believe:

My confusion and anger ended when our host stopped talking about models and paradigms for AGW and showed me the real physics: Schwarzschild’s equation for radiation transfer. This is the equation that climate scientist use to predict that a doubling of CO2 will slow radiative cooling to space by about 3.5 W/m2. Unfortunately, this equation is a differential equation that must be numerically integrated over the path radiation takes, and therefore may or may not be meaningful to you...

I do not pretend to understand this equation numerically, but the gist of is what common sense would tell us: some gases are better 'insulators' against radiation than others, in the same way that some gases are better for thermal insulation than others, so radiation (or thermal energy) comes out of one side more slowly than went in on the other - but it still gets through in the end. Wow, big deal.
Basic physics tells us that everything can radiate (we are told hat N2 and O2 can't, let's just accept that) and that the temperature of the atmosphere falls with increasing altitude (because of the gravity-induced lapse rate). Therefore, stuff which is higher up will be radiating less than the surface. Outgoing radiation is about one-third from the warmer surface and two-thirds from cooler clouds (which themselves have only about 75% emissivity) and if you average those out, you get the same answer as what is actually observed, which is what is needed to keep the atmosphere at a steady-state temperature.

PS, the figure of 3.5 W/m2 (which he himself dismisses as "barely more than a 1% change") is a key part of the Alarmist belief system. This was originally derived by simply assuming that warming over an arbitrarily chosen time period was directly caused by changes in CO2 levels. They later reverse engineered the answer they wanted from an equation not necessarily designed for this purpose. Even if correct, that equates to a surface temperature which is about 0.7 degrees warmer for every doubling of CO2. Again, big deal. (This is of course wholly at odds with Al Gore's claim that temperatures rise by about 1 degree for every 5% extra CO2, not that he ever retracted it or that the Alarmists even notice the discrepancy - if Al Gore's chart had been a good predictor, then temperatures would be about 10 degrees warmer than they actually are.)


Bayard said...

"They later reverse engineered the answer they wanted from an equation not necessarily designed for this purpose. "

AFAICS, the entirety of climate "science" is reverse engineering, starting with something they want to be true and scrabbling around for "data" to back it up.

Mark Wadsworth said...

B, this poor gullible chap Wanted To Believe and scrabbled round until he found an explanation whose fundamental illogic was not obvious to him. And now he is Saved and ready to Convert The Unbelievers.

If you go on these climate change porn sites, they argue heatedly about how many angels fit on a pinhead - whether MMGW is caused by back radiation, or effective emitting altitude, or TOA, or heat trapping, or how you can twist it to explain the lapse rate. They never question whether angels even exist.

Every now and then, one of them says "Ah, but Venus..."

Bayard said...

Venus, is she the Goddess of Global Warming?

Mark Wadsworth said...

B, sort of the anti-Goddess, the fallen angel.

The usual sources all say "Venus started with a bit of CO2 and this warmed the planet and that created more CO2 and that created runaway global warming. Venus atmosphere is 95% CO2 and the greenhouse effect is about 500 degrees of warming".

None of this is actually true, but many people believe it.

Dinero said...

> Mark

On the other comment thread You contemplate the scenario of making a warm object warmer by putting a cold object near it.
Well that it is not weird because the second objects stops the flow of IR moving away from of the warm object.
If the cold object was not there the IR would moved off into the infinite distance. But because it is there it adsorbs and re emits some of it back towards the source.
In the common vernacular of Physics warmer does not mean raising the temperature. It means decreasing the net loss of heat, or adding to the additional inward flow of heat. As everything without the addition of heat is cooling warming is understood to mean this. In everyday language warming often means raising the temperature, but there it is also used to mean reducing loss of heat ,for example no one thinks a "warm coat" creates heat. But is does keep the wearer from loosing heat.

Bayard said...

Din, you are Humpty Dumpty and I claim my £5.

Mark Wadsworth said...

B, for more hilarity in this vein, check out Dinero's comment at Science of Doom and the curt response from DWP. DWP is a devout Alarmist, but even he couldn't bring himself to agree.

Mark Wadsworth said...

For future reference, here is the article linked to in the next comment:

Analyzing changes in the complexity of climate in the last four decades using MERRA-2 radiation data

Dinero said...
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Dinero said...
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Dinero said...

Mark what I am asking there is in the same vane as the question that you asked. Although my question sharpens up the question. Lets see what they say. Do not add to the dialogue to my comment there yourself for the time being as it could distract from getting an answer to the question that SoDs article raises,

What is is your answer to the thought experiment.

If you had 100 tungsten filament IR lamps focused with 100 lenses on a 1mm length of tungsten wire could the tungsten wire be hotter than the temperature of the individual filaments. And what is the reasoning behind the answer.

Mark Wadsworth said...

Din, I don't know why you are asking me this.

The widely accepted physics is that you can't use a magnifying glass to make an object hotter than the source - it could theoretically reach the same temperature, but at that stage, it is radiating back as much as it receives and thus cannot get any hotter.

Dinero said...

I was trying to think of a more plausible question than your rhetorical question about the wafting air.
The filaments would be hotter than the wire as they would be receiving each others IR from the target via the path back through the lenses.
How about an object in an insulated box receiving IR through a small hole in the box.

Mark Wadsworth said...

Din, why don't you ask a proper old fashioned physics teacher? No point asking me, I just assume that basic physics is correct.