Wednesday, 8 December 2021

"How do we know more CO2 is causing warming?"

Easy, just measure A and claim you have measured B.

From the Motherlode of Shite, they make the obligatory and wrong assumption that sea level temp's should be the same as cloud temps (it is the clouds that absorb most of the arriving sunlight; not the sea level surface - this is the basis for the correct explanation of the Greenhouse Effect because that is what we are measuring - difference between cloud temp and sea level air temp = 33 degrees) and then crack on with the flimsiest of evidence:

The temperatures are going up, just like the theory predicted. But where’s the connection with CO2, or other greenhouse gases like methane, ozone or nitrous oxide? ... Is there a reliable way to identify CO2’s influence on temperatures [over that period]?

There is: we can measure the wavelengths of long-wave radiation leaving the Earth (upward radiation). Satellites have recorded the Earth's outbound radiation. We can examine the spectrum of upward long-wave radiation in 1970 and 1997 to see if there are changes.

This time, we see that during the period when temperatures increased the most, emissions of upward radiation have decreased through radiative trapping at exactly the same wavenumbers as they increased for downward radiation. The same greenhouse gases are identified: CO2, methane, ozone etc.

OK, CO2 tends to block and/or re-radiate infra red at about 14 nanometers (= about 700/cm), there's less going to space and more hitting the ground. Clever scientists say so and they have measured it and who am I to disbelieve them?

But WTF does that have to do with temperatures?

Wien's Displacement Law tells us the relationship between an objects temperature and peak frequency; the object absorbing that frequency can't get any warmer than the apparent* temperature of the emitting object. 14 nanometers = apparent temperature approx 200K (minus 73C).

* I say apparent because the actual average temp of the CO2 is about 250K, but it emits radiation as if it were only 200K, so can't warm anything up to more than 200K.

Even if CO2 emitted radiation at the shorter peak wavelength we would expect from an object that is approx. 250K, that wouldn't be able to warm an object (sea level surface) either, as sea level surface is warmer than that anyway. If you have a forge furnace burning coal at 2,000C, you can't use it to warm anything up to more than 2,000C, that must be obvious.

A 2,000 Watt three-bar electric fire is about 1,000 degrees C (I think, can't be bothered looking it up again). However close you hold something to the bars, even if it's only a millimetre away, it can't absorb so much radiation that it reaches a temperature higher than 1,000 degrees C.

Hold the same object a millimetre away from a 2,000 Watt radio transmitter and it barely warms at all. Radio waves are at very long wavelengths, so using Wien's Displacement Law, the apparent temperature of the transmitter (based on the wavelengths of the radiation it emits) is barely above absolute zero.


Lola said...

From memory your degree was in law and you work for an accounatnts
That is you're not a scientist.
So if a non-scientist can this easily debunk the MMGW/CO2 stuff, it rather indicates that the CO2/MMGW stuff is bollocks. Nesty par?

Mark Wadsworth said...

L, I'm a numbers guy. Accounting degree and ACCA was easy enough, tax exam was tougher and I only did the law degree later on (while working full time) for the fun of putting LLB after my name. It's a good job I didn't know beforehand how tough it would be or I wouldn't have started.

All of which is irrelevant.

Do I have anything more than an O Level in physics? Nope. So what? We are supposed to 'follow the science' and I do, I find it fascinating.

And 'the science' tells me that Warmenism is a crock of shit where they work backwards from the answer they want, which is not how science is supposed to work.

There's plenty of 'empirical evidence' to support Warmenist theory, the same as there was plenty of empirical evidence for the geocentric model. But whichever theory can explain the most with the fewest, simplest rules (heliocentric model) is probably the correct one.

Bayard said...

Besides, this "explanation" contradicts the second law of thermodynamics: "The heat can't go from the colder to the hotter, You can try it if you like, but you'd better notter..

Mark Wadsworth said...

B, the 2nd law is a bit irrelevant here actually and I wouldn't overplay it.

Facts: clouds are colder than the surface, but their presence leads to the surface being warmer than it would be in their absence in two main ways

1. By day, clouds absorb sunlight high up, because of lapse rate etc, surface is warmer than it would be. Because of high spec heat capacity of water, clouds cool down slowly so the effect continues through the night.

2. By night, clouds reflect some radiation back down to surface and/or stop the energy getting to space.

I guess the Alarmist people really are trying to say that CO2 works like clouds do in the night time.

That's clearly nonsense; for that to be true, the tiny bit of CO2 floating about would have to about five or ten times the insulating power of big fat massive clouds.

Bayard said...

M, AFAICS, the CO2 in the atmosphere is almost always going to be colder than the earth's surface, so a transfer of energy from the CO2 molecule to the surface is energy going from the colder to the hotter in contravention of the second law.

Mark Wadsworth said...

B, I know, a lot of people say that.

The Warmenist fall-back argument is that CO2 acts as a kind of thermal insulation - like clouds at night - and an insulating layer is by definition colder than the warm object it is insulating. Rest your hand on the top of the lagging in your attic, it should be colder than the ceiling (on a cold day). And if it's not, you need thicker lagging.

We hopefully all accept that cold clouds have an insulating effect; I see no evidence that the effect of CO2 is even a tiny fraction of what clouds do.

Clouds reflect or re-radiate up to 90% of radiation coming up from the sea level surface at all wavelengths. CO2 re-radiates max 50% of radiation coming up at a few (cold) wavelengths.

The night time insulating effect of clouds is only a few degrees (I googled it - absolute max about 5 degrees C IIRC) so any effect of CO2 re-radiating or indeed blocking must be immeasurably small.

So that nukes the counter-argument to the 2nd law argument (which I think is a weak argument anyway, but hey).

Bayard said...

"This time, we see that during the period when temperatures increased the most, emissions of upward radiation have decreased through radiative trapping at exactly the same wavenumbers as they increased for downward radiation."

No you don't, unless you have your Alarmist Blinkers of Blind Faith on. Right in the middle of that diagram (it's almost impossible to work out what it represents, but let's take their word for what they say it does) is one of the wavelengths emitted by CO2, which has not changed at all. OK, there is another CO2 wavelength on the LHS which has gone down quite a bit, but this is obviously more evidence of the demonic powers of this evil molecule in that it can choose at which wavelength it emits infra red.

Mark Wadsworth said...

B, those charts are complete nonsense.

But the rules of the game are, you take everything they say at face value.

And then work out why, even if true, it is irrelevant.