Guest Post by Barry Woods
All too often the ‘simple physics of CO2’ argument is presented to the public by the media, politicians, climate scientists and environmental advocacy groups, in a way that grossly simplifies the issue of the response in global temperature to increasing CO2 in the Earth’s atmosphere.
An excellent response to the simple physics argument is to be found in the comments at Climate Etc (Professor Judith Curry’s blog)
In reality my feather blew up into a tree
“….. which is that since CO2 is a GHG it follows that increasing CO2 must increase the temperature (of something). No matter how many times we say that the climate is a system with complex non-linear feedbacks they still love this simple principle of physics.
This is because physics works by isolating simple situations from reality. That was the great discovery of physics, that if you simplified reality you could find simple laws. So far so good.
But as every engineer knows, these simple laws often do not work when reality gets messy, as it usually is. Simple physics says that if I drop a ball and a feather they will fall at the same rate.
In reality my feather blew up into a tree.
It is not that the simple law is false, just that there are a number of other simple laws opposing it. In the case of climate we don’t even know what some of these other laws are, so we can’t explain what we see. That is where we should be looking.”
The ‘do you deny the simple GHG physics’ argument is also often an attempt to portray anyone that asks reasonable scientific questions about AGW and the complexity of climate science, as some sort of an ‘anti-science’, ‘flat earther’ denier.
The realities and complexities and unknowns of climate science are described in the IPCC working Group 1 reports, but somehow get ‘lost in translation’ into the Summary for Policymakers, for example (and everyone knows very few politicians even read beyond the executive summary of anything).
IPCC (Chapter 14, 14.2.2.2, Working Group 1, The Scientific Basis)
Third Assessment Report: “In sum, a strategy must recognise what is possible. In climate research and modeling, we should recognize that we are dealing with a coupled nonlinear chaotic system, and therefore that long-term prediction of future climate states is not possible.”
Time and time again the media and environment groups ignore this IPCC fact that the climate is a coupled nonlinear chaotic system and that the worst case scenarios of the computer model ‘projections’ or scenarios (because they know they cannot use the word prediction) latest example, 4C by 2060, are just one result of computer model ‘runs’ programmed with various extreme values of these assumptions.
The low-end ‘projections’ of temperature by model runs with other values and assumptions are ignored completely by CAGW advocates, the data output or projection of a computer model transmorphs into a scientific fact, the data output of a computer model becomes evidence of CAGW.
Climate Science is often portrayed to the public in simplistic terms as a mature science, narrowed down and focussed onto one primary factor – CO2, assuming all else to be equal, and not the possibilities in this type of system that varying one parameter alone, may vary other parameters in non-linear ways, even potentially flipping some from positive to negative feedback (or vice versa)
At the time of the Copenhagen Cop 15 Climate Conference, stunts on TV, rather than the discussion of uncertainties of ‘climate science’ were the order of the day.
The classic demonstration of the ‘do you deny the simple physics of CO2’ argument is a glass tube filled with CO2, heated and then the TV presenter or preferably a senior government scientist says ‘look it has warmed!’ –
As demonstrated by the BBC in their Newsnight program, Copenhagen Climate Conference time, the BBC’s apparent intellectual response to the climategate emails and documents. Watts Up With That, gave a critique of this particular type of TV experiment and CAGW PR.
I wonder what would have happened if a member of the audience had been able to question their methodology, or even ask simple questions like:
What is the percentage of CO2 in the jar?
ie total atmospheric is ~0.038%, what percentage is in the glass jar – 50% plus perhaps, or more?
[Corrected typo spotted in comments – 0.038% / 380 ppm]
If you were to mention that the CO2 effect is logarithmic, then you are likely to be labelled a ‘climate change sceptic’ or worse a ‘climate change denier’ by any passing MSM media TV presenter, environmentalist group or AGW consensus minded politician, and then they will simply stop listening, because you are obviously a fossil fuel funded denier, such has been the CAGW consensus PR.
I wonder if for a sceptical joke, someone could produce a spoof YouTube video of a feather and a cannon ball in a glass jar experiment (non evacuated) and the TV presenter could say to the audience:
“Proof – The Cannon Ball FALLS faster that the feather – Simple Physics clearly show this”
Someone in the audience could then ask, but you have air in the jar? and then get ridiculed by the group as an ‘anti-science’ denier, the scientist/presenter could even bring out the ‘No Pressure’ red button to use!
The simple and not so simple physics of a number of climate parameters, are programmed into the climate computer models. Many of these parameters, it is acknowledged, are not completely understood or that there is serious contentious debate about in the scientific literature. ie aerosols, clouds, solar pacific and atlantic oscillations, volcanoes, etc,etc
Engineers (or economists now, perhaps) will advice climate scientists, model are not reality, reality is often more complicated than any computer model. Take a step back, view with hindsight with respect to risk in the financial markets. At the trouble the cream of the last few decades of science graduates – turned computer modellers – left the world’s economy in, following the modelling of credit risk amongst many other economic assumptions.
Next time anyone starts on about the simple physics of CO2, remember the feather and a cannon ball in a very large glass jar analogy, or for the classically motivated, atop the Leaning Tower of Pisa.
Politicians could lay trillion-dollar bets, and dozens of competing scientific groups (publically funded) could even attempt to write a computer models to predict when and where the feather would land…………
Thanks again to Anthony for the opportunity to write at Watts Up With That again. There is a little more about me here.
Or maybe you could stop by at my new blog, I hope that the Watts Up With That regulars like the name.
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Ric Werme says:
Why are so focused on CO2?
BECAUSE, AGWScience has turned it into a poison, capable of doing supermolecule feets such as staying up in the atmosphere accumulating for thousands of years bringing the earth to boiling point by flipping a bit of IR back..
There was even a AGWscientist recently who set off to prove that the atmosphere in a mine was well mixed and that methane, being lighter than air, although it might rise to the ceiling (reluctantly admitted because the weight of observation in real science can’t be denied), will diffuse through the air and mix thoroughly with the rest of the atmosphere in the mine. A lighter than air version of my heavier than air example of CO2.
He came away utterly confounded, because the methane stayed in a layer at the ceiling.
He said, ‘there must have been a source of methane coming into the mine rising to the ceiling replacing that which was diffusing in air, but we couldn’t find it.’
He couldn’t find it because it wasn’t doing that. He was using an ideal gas law to describe what a real gas would do, and it doesn’t apply. Gases that are lighter than air, rise in air. In a confined space such as a mine methane will pool in a layer at the ceiling. Any carbon dioxide in the mine will pool in a layer at the ground. That’s the real world. AGW has stepped through the looking glass, full of impossible phyics.
AGW has so contorted real physics by teaching this misapplication of ideal gas laws to real gases that this man, real adult educated scientist in real adult community, didn’t know that. And it was his subject.
How can AGW say carbon dioxide is a poison, and frighten children with this at bedtime story telling, when it is absolutely essential to our lives and all life on earth? Because they’ve lost all sense of reality.
The ideal gas, to which only the ideal gas law applies, is imaginary. It’s a construct. Ideal gas laws do not apply to real gases. Read the differences in the links I posted. “Imaginary” is how “ideal” is actually described in real physics, just as “average” is a construct. Some people think that when ‘average annual rainfall’ is given, this means it’s the amount that falls every day…
Applied scientists, whose work is dependent on knowing the difference between real and imaginary gases, will be able to explain it better than I.
tokyoboy points out the painfully obvious:
December 29, 2010 at 10:14 pm
> The molecular weights of N2, O2 and H2O are 28, 32 and 18, respectively, although this may not affect the essence of your comment.
I can’t believe I screwed that up so badly! Fortunately only the ratios are important. Something about that H2O being 10 didn’t sound right and should’ve prompted a sanity check.
Excuse me while I go crawl under a pool of CO2….
“”””” Ric Werme says:
December 30, 2010 at 4:47 am
tokyoboy points out the painfully obvious:
December 29, 2010 at 10:14 pm “””””
Well Ric, I don’t think I’ve ever done that; make a misteak, that is. Well there’s a lot of things I don’t think. Need some company under that CO2 ? Come to think of it, why don’t we just skate on top of it; or ski on the CO2 snow (at Vostok); I can’t stand the pressure of that liquid CO2.
“”””” Myrrh says:
December 29, 2010 at 9:42 pm
stephen richards Pure CO2 kills animals and Humans and, I think someone has shown that death has occurred at above 7000ppm but the O2 content was not measured.
John Day The concentration of CO2 in your lungs right now is 40,000ppm (i.e. ~4% CO2). You’re not feeling dead, or a bit woozy now are you?
You might start to be, that is a dangerously low level, below that which the lungs require to transport oxygen healthily – you could be heading for an asthma attack at this level which is the lungs response to low levels of CO2. “””””
Well Myrhh, I think you have your maladies maladjusted.
Asthma doesn’t have anything to do with the lungs; it is a constriction of the duct leading from the throat into the lungs; the gas exchange mechanisms of the lung surfaces are not affected in any way by Asthma; and I should know since my whole life and career rest on having been a major heavy duty asthmatic as a kid. Without that asthma I would now be a retired very rich former sheep farmer in New Zealand.
Folklore has it, that the traditional Maori treatment for drowning, called for stringing the victim; excuse me, the patient, up by his ankles (with a flax rope of course) over a fire of hot coals, with leaves on it to make smoke, and get his luungs full of CO2 to trigger the coughing, and breathing response.
I used to hold my breath for two minutes (while underwater swimming) and the biggest problem was mentally resisting the breathe out urge that is triggered by the build up of CO2 in the lungs.
My guess is that the disease that interferes with the gas exchange mechanism at the lung surface is Emphysema; not Asthma.
Myrrh says:
“AGW Science says a molecule of gas heavier than air can rise through the volume of air above it and rapidly diffuse through it thoroughly mixing with all the other molecules, because AGWScience says air is empty space with molecules at great distances apart from each other zipping at enormous speeds randomly through it. AGWScience says a molecule of gas that is heavier than air can stay up in this its atmosphere for hundreds and thousands of years, even though it is heavier than air, because etc.”
Not just “AGWScience” – Einstein said as much – one of his 1905 papers was on Brownian Motion. Dust particles millions of times heavier than simple molecules also stay in the atmosphere for long periods of time.
There are opposing tendencies at work – gravity and diffusion. Diffusion is governed by Fick’s Laws, the most important explaining how diffusion occurs from higher to lower concentration. Over time Fick wins, and all gases apart from water vapour (which may change state between gas and liquid) mix more or less completely.
Gases in a mine take longer to mix, because they can’t diffuse sideways. If there is a constant source of gas, which may occur in a mine or a swamp or volcano, there will be a constant concentration gradient until the source expires.
“”””” Myrrh says:
December 29, 2010 at 7:06 pm
Joel Shore says:
December 28, 2010 at 8:30 pm
re through the looking glass with Alice I can pretty much assure you that the person you had the discussion with must have felt likewise.
Oh yes, that was made quite clear to me… (grin)
..it’s nice to be back…
All models are approximations. However, the ideal gas law is a very good…perhaps even excellent approximation…at atmospheric densities.
How so?
Please look at the table at the bottom of this page tabulating the differences between Real gases and Ideal gases: http://www.tutorvista.com/chemistry/difference-between-ideal-and-real-gases
The atmosphere I live in is Real, Real Science applies there. “””””
Well hold on there pardner ! I have to come to the defence of Joel Shore here; regarding Ideal Gas Laws.
Joel may be a bit misguided; but he generally has his facts pretty straight; and he said here:- “”””” However, the ideal gas law is a very good…perhaps even excellent approximation…at atmospheric densities. “””””
Shall I repeat : “”””” …at atmospheric densities. “””””
The Ideal Gas Equation of State is: pV =NkT where the terms are: pressure, Volume, No of particles, Boltzmann’s konstant, and Temperature.
Contrast this with Van der Waals equation which better approximates many real gases.
(p + (n/V)^2.a)(V-nb) = nRT
Well we have an adder term to the pressure (p) and a reduction of the Volume (V) and we have nRT in place of NkT.
Well (n) is the amount of substance in mols, instead of (N) the number of particles (molecules), and R is of course the Universal Gas Constant, = 8.314 J/K.mol
And wouldn’t you know it but nR = Nk , how about that !
So the difference is those two extra terms; so what the hell are they all about ?
Well the – nb term is easy; (n) is of course the number of mols of gas and (b) is a “constant of internal volume”. Well (b) is a constant for any one particular gas (m^3/mol ) .
Surprise ! molecules take up space; not much space but they do take up some. The molecules themselves are not particularly compressible; they kind of like the way and size they are, so at ordinary pressures the molecules take up a fixed volume. That volume is NOT available to be compressed, in the pV = NkT ideal gas equation. The actual available compressible Volume is less than V by that amount (nb)
So if we simply offset that tiny microscopic incompressible volume of the molecules themselves, then our real gas behaves much more ideal like.
So what is that pressure adder term (n/V)^2.b ?
Well in the interior of the gas, the molecules generally attract each other, mostly from small dipole effects. In the bulk of the gas, of course these forces pull in all directions so they cancel out; but not at the boundary, since there’s no molecules outside that to pull. So the gas tries to pull in on itself much like a surface tension effect; so there is an internal pressure excess over that applied from the outside containing walls; hence the slight adjustment to the pressure.
Then we are right back to the ideal gas relationship. (a) of course is also a “constant of internal pressure” that is characteristic of each gas, with units of Nm^4/mol^2 Careful now; THAT (N) is Newtons, not the number of particles.
Now back to our atmosphere, and Joel Shore’s assertion. Really our atmospheric pressure is peanuts, and the mean free path between molecules, is astronomical compared to the radius of a molecule, so the internal volume adjustment is very small, and for the same reason (low pressure), the internal pressure adjustment is small. Liquids with their much greater density and closer molecular spacing exhibit easily perceivable surface tension contracting forces; much larger than gas internal pressures.
So Joel is on very solid ground, when he says that the Ideal Gas Law is fine for the atmosphere, at normal STP conditions.
You have to be a lot faster on your feet to catch Joel in an error; he does his homework; still a bit misguided.
edmh says: “Without the Greenhouse Effect the planet would be un-inhabitable at ~-18 degC.”
edmh, I think that has been shown wrong – total greenhouse effect is not +33° but significant less – see greenhouse effect on the moon:
http://www.ilovemycarbondioxide.com/pdf/Greenhouse_Effect_on_the_Moon.pdf
Lars P: No…Nobody serious takes Herzberg’s analysis (that you linked to) seriously. And, that includes skeptical scientists like Roy Spencer. At least one of the things that confused Herzberg is that he didn’t seem to understand that the fourth-root of average of T^4 is not the same as the average temperature. Technically, the blackbody temperature of a planet or moon would be a constraint on the fourth-root of average of T^4 because that is what controls the amount of radiation going back out into space. For a planet like the earth where the large specific heat keeps temperatures from oscillating so wildly with the diurnal cycle, this is a small effect but for something like the moon this is a large effect.
@Larry Plume P
The moon’s average surface temperature is -23C measured by thermocouples buried in the regolith at a depth of one meter. Measurements were made for four continuous years at two different landing sites. Annual variation in temperature disappears at a depth of one meter.
Thermal conductivity of the surface i.e. the ability to store heat absorbed during the day and release it at night only lessens the difference between day/night surface temperature. The preliminary estimates you cited for lunar surface temperature underestimated the thermal conductivity of the regolith. At the time no one knew the density of the lunar surface. Some believed it was a fine flour to a depth of several meters and the lunar lander would sink out of sight. As it turns out it was packed much more solidly – so solid in fact that the regolith thermal conductivity experiments from which I pulled the temperatue data at one sight couldn’t be drilled to the maximum specified depth of 3 meters.
If the earth had no atmosphere and the surface was the same mineral composition of the moon, which it would be in that case, they would be the same average temperature of -23C. The earth’s average temperature today is 13C which is very close to the cited rise of 33C.
There’s a caveat however. The moon’s average albedo is about 16% while the earth’s average albedo is about twice that although it’s very difficult to measure earth’s albedo and estimates vary from low 30’s to high 30’s percent. So theoretically the earth should have an average temperature much lower than the moon without greenhouse gases but then again since water vapor is a greenhouse gas and without water vapor we wouldn’t have clouds and without clouds the surface albedo would be lower than the moon as the ocean’s abedo is near 0%.
Water messes up all the calculations. IMHO the primary effect of non-condensing greenhouse gases is that they warm the surface just enough so that we have a global ocean with a predominantly liquid surface. When that happens enough water vapor enters the atmosphere so that it takes over the temperature control and because water vapor is a condensing GHG it puts a cap on how much greenhouse warming it can accomplish through a negative feedback inherent in cloud cover i.e. when it gets warmer there are more clouds and more clouds raise the albedo which makes it cooler.
The fact that non-condensing greenhouse gases are historically very low probably has a lot to do with why the earth has for the past 3 million years been in an ice age.
In short simplified form CO2 prevents the earth from runaway freezing and water vapor prevents runaway warming. At the present time we’re in danger of runaway freezing which has happened several times in the earth’s history and in no danger of runaway warming which has never happened.
Steve from Rockwood says:
December 29, 2010 at 3:38 pm
“Is CO2 really toxic or is the lack of O2 toxic?”
Yes. Not enough oxygen and you suffocate. Too much CO2 and you get acidosis and die of it because blood pH becomes too low for critical metabolic chemistry to work as it should. CO2 toxicity is not a concern due to anthropogenic sources in open atmosphere as the toxic level is far higher than we could possibly make it through burning fossil fuels.
George E. Smith says:
December 30 2010 at 9:23 am
I said: You might start to be, that is a dangerously low level, below that which the lungs require to transport oxygen healthily – you could be heading for an asthma attack at this level which is the the lungs response to low levels of CO2.
You said in reply: Asthma doesn’t have anything to do with the lungs; it is a constriction of the duct leading from the throat into the lungs; the gas exchange mechanisms of the lung surfaces are not affected in any way by Asthma;
OK, I haven’t heard that before. This below is what I understand to be what happens:
http://www.articlesfactory.com/articles/health/asthma-status-asthmaticus.html
“Asthma attacks are caused by the a narrowing of the small bronchial tubes in the lungs .”
“Question: How does asthma interfere with breathing?
Air passes through the lungs via tubes (called bronchi) and smaller vessels (bronchioles). With asthma, the smaller bronchi and bronchioles become swollen and clogged with mucus, and the muscles surrounding the bronchioles contract so that the air that should pass through is unable to do so. The body reacts to the lack of oxygen, and the patient forces more and more air into the lungs. But, because of the blockages, there is difficulty in exhaling it. The wheezing noise is caused by air being forcibly exhaled through the narrowed bronchi.
There are many reasons for asthma attacks, for the bronchioles to become narrowed, infections, allergies and so on. Emphesema happens when the lungs are continually stretched over time from them not being able to expel the oxygen.
One of the causes of this narrowing is when there is insufficient CO2 in the lungs.
Because CO2 is crucial to oxygen getting to where it is needed in the body, a lung full of oxygen on its own is not enough. This is where the effect of an asthma attack comes in, when the lungs are full of oxygen but not able to empty and the discomfort mounts, because without CO2 the oxygen can’t being used. I’m not sure I’m explaining it well enough here.. But, when there is insufficient CO2 in the lungs, which the body itself produces, the reaction is for the bronchioles to narrow (as in an allergic reaction cause), because the body is trying to conserve CO2 content in the lung (as from a link above, this is 4% of exhaled air); so it’s the body’s defence reaction because it needs CO2 to utilise oxygen – the lung full of oxygen an asthmatic has in an attack can’t be used by the body until there is sufficient level of CO2 to transport it.
Because there are different reasons for asthma attacks I’m not saying that if you introduce extra CO2 your attack would stop… It’s just that an asthma attack, from the effect of bronchioles narrowing, is what would happen if for some reason there was insufficient level of CO2 in the lungs and the body began to panic because it couldn’t get the oxygen to the vital functions. It closes down the bronchioles to conserve supplies.
I’ve read that cure for drowing before, amazing, and sad to imagine how much we must have lost now that native knowledge is teaching us from those places where it hasn’t been. I don’t know what will happen next in our ‘western’ world as the pharmaceutical companies are getting cleverer and more powerful. They’ve just started a big attack on herbal remedies, I think an EU initiative, I missed the beginning. The two journalists discussing it (on a Sky Press Preview a couple of days ago), were appalling, couldn’t tell the difference between AGW press promoting journos and these. One said, ‘do you know that none of the Chinese herbal medicines have been tested?’ with a shock horror face. At that point, feeling the beginnings of a scream coming on, I switched off the TV.
Dave;
That’s kind of an abuse of the term “toxic”. The list of substances which are “toxic” at unlimited concentrations is very large, approaching universal. Read Charles Sheffield’s sf opus “Nitrogen Fix” for a fun excursion on that gas! In that “climate”, oxygen is a deadly poison.
Oops, Hal Clement, not Charles Sheffield. Neuro-RAM failure, had to check the backup files.
George E. Smith says:
December 30, 2010 at 9:06 am
“”””” Ric Werme says:
December 30, 2010 at 4:47 am
tokyoboy points out the painfully obvious:
December 29, 2010 at 10:14 pm “””””
Well Ric, I don’t think I’ve ever done that; make a misteak, that is. Well there’s a lot of things I don’t think. Need some company under that CO2 ? Come to think of it, why don’t we just skate on top of it; or ski on the CO2 snow (at Vostok); I can’t stand the pressure of that liquid CO2.
[Oops, let’s try that again…]
George E. Smith says:
December 30, 2010 at 9:06 am
> Need some company under that CO2 ? Come to think of it, why don’t we just skate on top of it; or ski on the CO2 snow (at Vostok);
Let’s not go there (Vostok) – I’m not ready for that topic again!
PhilC says:
December 30, 2010 at 10:00 am
Not just “AGWScience” – Einstein said as much – one of his 1905 papers was on Brownian Motion. Dust particles millions of times heavier than simple molecules also stay in the atmosphere for long periods of time.
Because of the motion of the medium they are in. The medium of the atmosphere is air, air is a gas. Made of real gas molecules which have volume etc. as per the differences on the link I posted.
“Brownian movement – Continuous random motion of particles in a fluid medium (gas or liquid) as they are subjected to impact from the molecules of the medium.” http://encylopedia.farlex.com/Brownian+motion
There are opposing tendencies at work – gravity and diffusion. Diffusion is governed by Fick’s Laws, the most important explaining how diffusion occurs from higher to lower concentration. Over time Fick wins, and all gases apart from water vapour (which may change state between gas and liquid) mix more or less completely.
http://en.wikipedia.org/wiki/Diffusion
Please read the first two paragraphs, the second of which ends “Under normal conditions, molecular diffusion is relevant only on length scales between nanometer and millimeter. On larger length scales, transport in liquids and gases is normally due to another transport phenomenon, convection.”
Note the term “normal” and “transport in liquids and gases”. Third paragraph:
“Therefore, some often cited examples of diffusion are wrong: If cologne is sprayed in one place, it will soon be smelled in the entire room, but a simple calculation shows that this cannot be due to diffusion; the cause can only be convection. If ink is dropped in water, one usually observes an inhomogeneous evolution of the spatial distribution, which clearly indicates convection; diffusion dominates only in perfect thermal equilibrium.”
So, molecular diffusion only on tiny scales. Hence my example of sound travelling through space, which is the gas air, the medium. The molecules of the gas air are not diffusing in the room, any more than the molecules of water are diffusing in the sea. The molecules may be moving very quickly, but they’re going nowhere fast. (Unless convection currents, etc.)
Convection is “work”. The room in my thought experiment did not have anything added to change the circumstances in which the CO2 pooled.
Gases in a mine take longer to mix, because they can’t diffuse sideways. If there is a constant source of gas, which may occur in a mine or a swamp or volcano, there will be a constant concentration gradient until the source expires.
Gases can’t diffuse sideways?
Anyway, as above, molecules diffuse only on very small scales. At these distances the weight of the molecules relative to each other takes effect. In a mine, the lighter than air methane molecules will rise to the ceiling, forming a layer. The heavier than air carbon dioxide molecules will displace the lighter nitrogen and oxygen molecules and sink to the ground, forming a layer.
It’s a fact. Well known, especially by those working in conditions where their life depends on knowing it. Miners check for methane layer when in new mines, the bog standard method of doing this was to cover oneself in wet towels and enter with a lit candle at the end of a long stick to poke into the ceiling space.. Even better known and common, observable by everyone, normal knowledge, is the fact that dust particles being heavier than air will sink, and settle on whatever the object around that is their ground; tables, chairs, tops of doors, floor. It doesn’t matter how long you give it, the dust will not diffuse to mix thoroughly with the air in the room. Not without a lot of energy imput, a very strong fan continually blowing into every part of the room, for example. Our atmosphere is not like that. Leaves would never fall on the ground.., we’d be choking on the debris of billions of years.., the whole lot would have turned into a compost heap and we’d probably be something like fungi or bacteria; we couldn’t have evolved as we are in such an atmosphere…
George E Smith says:
December 30, 2010 at 10:16 am
Well hold on there pardner! I have to come to the defence of Joel Shore here; regarding Ideal Gas Laws.
That sentence I can readily understand, communication has been established. The rest of it is gibberish to me… and I don’t have the time or motivation to learn a new language. Where you, others too, explain using maths, I require descriptions in English, so a companion commentary explaining these will be gratefully received.
Of what I think I can understand:
In the bulk of the gas, of course these forces pull in all directions so they cancel out; but not at the boundary, since there’s no molecules outside that to pull. So the gas tries to pull in on itself much like a surface tension effect; so there is an internal pressure excess over that applied from the outside containing walls; hence the slight adjustment to the pressure.
What are the containing walls of our atmosphere?
Then we are right back to the ideal gas relationship.
Which creates wonderfully imaginative worlds in an imaginary atmosphere.
George E Smith (anybody called Smith must be talking sense) said the effect of greenhouse gases was like the soap basin falling into the bath and partially blocking the open plughole. As this interrupts the flow, the water level will rise (as the taps are running) until equilibrium is reached and the flow out equals flow in. (Simple physics.) But does an open atmosphere behave like a bath of water? As CO2 absorbs and emits energy (including warming air molecules in collision) it cannot reduce the flow of energy like a soap basin reduces the flow of water. Water vapour has the ability to absorb energy in the form of latent heat, but CO2 cannot. The reality of a bath is not the reality of the open atmosphere.
I see. Dave, Joel, thanks for the explanations!
Dave Springer says: “the ocean’s albedo is near 0%”
Dave, do you know of a calculation for average temperature considering if the planet were only water no atmosphere? (of course considering ice/water cases) I searched for some but could not find. Based on “common sense” I would say that due to the large area covered by water, water’s high specific heat capacity, and the fact it allows rays to heat more in depths then rocks do, a water planet would behave differently then a rock planet.
So in my simplistic view I though the oceans dictate the average temperature and atmosphere is actually just messing around through increased albedo, kinetic energy, etc.
Myrrh says:
December 30, 2010 at 10:34 pm
Good ol’ Wikipedia. They should’ve included “advection”, the horizontal transport of air. Think Canadian high blowing sub-zero cold air on to my nose in New Hampshire. Not a bad thing, Canadian air is good stuff, at least away from tar sands and forest fires.
Yeah, for the most part. A typical cloudfree weather day here starts with cold air chilled by the ground, and often pooled in valleys, depressions, etc. Definitely a case of denser air not mixing with less dense air that doesn’t radiate as well as the ground.
So, we wind up under an inversion and no wind.
When the Sun rises, its radiation that reaches the ground heats up the air until convection sets in and the inversion disipates. At that point, the local temperature rise slows way down, as the air is now “neutrally buoyant” and very little energy is required to move parcels of air up and down. The wind picks up as wind streams several thousand feet above can be deflected downward as the ground level air convects upward.
Things repeat the next evening, assuming clear sky allows for radiational cooling and the ambient wind isn’t strong enough to scour out the chilled air before it has a chance to form a new inversion.
Let’s see, where are we now? Separation by density is seen in basements about to explode, mines about to explode, and radiational cooling sites. It’s not seen in places where there’s air is moving and mixing. For meteorological purposes, I ignore diffusion. It’s just a second order effect and is vastly overwhelmed by the merest of zephyrs.
“For meteorological purposes, I ignore diffusion. It’s just a second order effect and is vastly overwhelmed by the merest of zephyrs.”
That makes sense.
Lars P says:
No…The average temperature of a planet without an IR-active atmosphere (and negligible internal generation of heat) would be dictated by simple energy balance principles. Such principles would state that the radiative power in equals the radiative energy out. The radiative power in is pi*(r^2)*(1-a)*S_0 where r = radius of the planet, a = albedo, S_0 = solar constant at the radius that the planet orbits the sun. The radiative power out is given by 4*pi*(r^2)*sigma*emissivity*T^4 where sigma is the Steffan-Boltzmann constant, T is the absolute temperature, and emissivity is a number between 0 and 1. Of course, if the planet is not at a uniform temperature and/or does not have a uniform emissivity the emissivity*T^4 would be replaced by where is the average of that quantity over the planet’s surface.
Most materials making up the surface of a planet have an emissivity within a few percent of 1.0 in the far infrared (where the radiation is emitted), although apparently desert sand can deviate a little further than that. So, basically, the average of T^4 can be easily calculated. If the variations in temperature on the planet (in time and space) are not too large than the fourth root of will be pretty close to .
As for the effect of the oceans, their large heat capacity comes into play mainly in reducing the temperature variation on the surface of the planet (and, thus, the diurnal variations in temperature). To the extent that the reduced temperature variations change without changing then I supposed that it can affect the “average temperature” a little bit but it main affect is on the variation in the temperature.
Now, if you add in an IR-active atmosphere then things change. Basically, it is still true that the radiation from the planet has to balance what it receives from the sun but this can occur by having the radiation back out into space occur from some effective height up in the atmosphere (really a range of heights described by a probability distribution) and the surface of the planet itself can be considerably warmer than the temperature in the atmosphere at this height.
“””””” Myrrh says:
December 30, 2010 at 10:59 pm
George E Smith says:
December 30, 2010 at 10:16 am
Well hold on there pardner! I have to come to the defence of Joel Shore here; regarding Ideal Gas Laws.
That sentence I can readily understand, communication has been established. The rest of it is gibberish to me… and I don’t have the time or motivation to learn a new language. Where you, others too, explain using maths, I require descriptions in English, so a companion commentary explaining these will be gratefully received. “””””
Well Mryhh, that sounds to me like you just punted.
You castigated Joel Shore because HE explained in reasonable words, that for the pressures of ordinary atmospheric conditions, the difference between the ideal gas laws, and the behavior of real gases; at least those of the ordinary atmospheric gases which are typically well modelled by the Van der Waals extension of the ideal gas law, is small enough to be entirely ignored; certainly for any climate considerations.
Now all that I did was to put some quite elementary quantitative padding on Joel’s statement; to make it clear that Joel’s position is indeed quite reasonable.
The “derivation” of the VdW extension of the ideal gas law, is something anyone can understand.
The available space in a Mall parking lot, is reduced by the finite size of the cars themselves. You can only compress that empty space down, until the (incompressible) cars are touching each other.
Molecules take up a finite space; and that part of the total is not amenable to compression in the manner the ideal gas law contemplates.
The excess internal pressure is perhaps a little more difficult to understand but not so much. The molecules typically pull on each other; but in the bulk of the gas, any one molecule is being pulled every which way, by its neighbors in every direction; so none of them really notice a net pull.
But when you get to the boundary of the gas (container walls), the gas molecules are being pulled inwards towards the rest of the gas; but there is no matching pull outwards, so at the boundary, the additional pressure is apparent to the container.
With those two simple adjustments, the resultant formula approximates the observable behavior of real gases, over a very wide range of Temperatures and Pressures; much wider than any atmospheric gas conditions ever experienced.
Science is a quantitative discipline. Cause and effect can only be established, when one can place some limits on measurable size of effects.
A typical example of the conundrum is the currently popular Svensmark theory about cosmic ray effects on cloud formation.
I’m quite certain that cosmic rays can and do nucleate cloud formation.
Dr Leif Svalgaard is less than enthused about the effect. But he hasn’t denied the effect; simply queried whether the present levels of cosmic ray flux on earth can explain a significant part of cloud formation variability. I understand that concern; it is the old story of the beat of a butterfly’s wing in a Brazillian rain forest; and a subsequent tornado in Kansas.
If you yourself are unable to follow the mathematics that goes along with Physics; and that is not a sin or a disease; then you probably would do better if you took observations of people like Joel Shore, a bit more seriously.
One thing you will find at WUWT, is that there are enough chaff detectors to see that totally non-credible statements by posters; don’t go unchallenged for very long.
I’ve had to eat crow often enough myself; when I came up with somer avant garde concept; that got mowed down. That’s why I come here; to learn from those who know a damn side more than I do. Joel is not known to simply make stuff up. I disagree with him a lot; but I agree with him, a lot more than we disagree.
I’ve had to eat crow often enough myself; when I came up with some avant garde concept; that got mowed down. That’s why I come here; to learn from those know a damn side more than I do. Joel is not known to simply make stuff up. I disagree with him a lot; but I agree with him, a lot more than we disagree.
Well, this could be another opportunity for you..
Let me just remind you of what my point is here. That AGW presents a version of CO2 that is utterly at odds with its known properties. Most of what is argued about CO2 between antis and pros is IR and all that, but, what interested me was there was hardly even a mention of the claims by AGW about its weight, and I couldn’t find any arguments from antis which looked into this. So, I did it myself. These, my posts above, are my findings.
The two claims made by AGW and presented as ‘it is very well known’, i.e. as if it is real physical science are 1) that CO2 is very well mixed in the atmosphere and 2) that CO2 stays up in the atmosphere for hundreds, thousands, of years, accumulating.
This is do with the weight of CO2. CO2 is 1.5 times heavier than air. What is very well known in RealScience is that gases in our atmosphere which are lighter than air will rise, gases which are heavier will sink. They’re doing it all the time. Water vapour is lighter than air and rises, gases which are warm become less dense and rise, weather is tracked by knowing this.
Yet somehow, CO2 doesn’t obey physical laws anymore in AGWScience. I wanted to know why, what the reasoning was behind these claims. What I found was straight ideal gas laws applied directly in concept to explain real gases, the behaviour of CO2 in the above 2 points related directly to this misuse of ideal gas laws. The ideal gas is imaginary, it is not real, and no ideal gas law applies to a real gas – is basic physics. I’ve given the differences, I’ve posted a link to a table where side by side you can see the differences.
I’ve given the thought experiment I went through this with to discover why AGW was teaching such nonsense. He was a physics PhD. I’ve been through this. He claimed that CO2 was acting as AGWScience presented it: that it could stay up in the atmosphere for hundreds of years, that even though it was heavier than air and with no work being done to move it, it having pooled on the ground would rise up and diffuse in the atmosphere in the room. This is absurd. This is contrary to all observation of CO2 in the real world. As my examples show. Yet, still people think that CO2 in a mine will of its own volition diffuse into the atmosphere, and still they think, as Joel’s question to me, that it is very well-mixed in the atmosphere -regardless of information from real observation and real data which shows CO2 acts consistently with its known properties and with known RealScience about diffusion and convection.
So please, stop arguing for Joel, it’s becoming a bit tedious, go through what I’ve been saying here and engage with what I’m actually saying. And answer the question I asked you. What are the walls of the atmosphere?
Joel asked me a question, I answered him. He didn’t come back to argue. So don’t tell me I’m arguing with Joel, I’m arguing with you.
Myrrh says:
No, you are arguing with me, George E. Smith, Ric Werme, PhilC, and Werner Brozek. We are not generally a group of people who all agree on issues related to AGW, but we all agree that you are wrong on this point because it is not really an issue of AGW but an issue of basic science.
So, your claim here makes some definite predictions:
(1) There should be a lot of CO2 near the ground and it should decrease as you go up in the atmosphere.
(2) There should be less H2O vapor near the ground and it should increase as you go up.
(3) Near the ground, there should be more oxygen and less nitrogen (because oxygen has a molecular weight of 32 and nitrogen of 28) and the ratio of nitrogen to oxygen should increase as you go up.
Now, you might try investigating how these predictions compare to reality, i.e., actual data. I’ll tell you what you will find:
(1) CO2 does not have significant variation with height, except that very near the ground it can be locally higher than the value generally quoted because of nearby sources.
(2) For H2O, the behavior is generally the opposite of what your hypothesis predicts. I.e., there is more H2O vapor near the ground and less as you go up. The reasons for this are a combination of where the sources are (near the ground) and the fact that H2O is a condensable gas, meaning that it doesn’t stay in the atmosphere long enough to become well-mixed and, in particular, at higher altitudes where the air is colder, the saturation concentration is lower which limits the concentrations at higher altitudes.
(3) There is no appreciable change in the fractions of O2 vs N2 as you go up in the atmosphere.
And, as I and others have tried to explain to you, there are well-understood reasons why, despite the difference in weight, gases in the atmosphere tend to mix. The basic point is that the lighter the elementary constituent is (which in the case of a gas, is the individual molecule) then the less important are gravitational effects relative to other effects such as diffusion and bulk atmopsheric motions (advection, convection, etc.). Another way to look at it is an energy vs. entropy thing.