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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LazyTeenager says:
December 28, 2010 at 4:34 pm
Barry, every physicist knows that feathers will be affected by air resistance. They wrote the book on the subject after all. So stop trying to deceive people into believing that physicists are simple minded.
Physicists also know that only a few objects in this world are feathers. Apparently you don’t know that.
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Lazy, you’re missing the point of the post. Re-read the first paragraph (I’ll make it easy.)…….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.
Barry was making the point that often alarmists use the “simple physics” as an argument and Barry pointed out that it wasn’t that simple. In a very angry way, you made his point.
BTW, I’d like to point out that while “very few objects are feathers”, there are many that have the characteristics appropriate for Barry’s example; leafs, dandelion seeds, spider eggs, certain blades of grass, etc….
Sometimes, deep breaths and a different perspective may help prevent these hyperventilations.
LazyTeen said:
“Err no. The model output is the consequence of the theory. The consequence of the theory is compared with the observations.”
Err no. The climate model is a consequence of crude truncation of hydrodynamics down to “primitive equations” of meteorology, which have no viscosity. More, all naturally occurring and normally “prognostic” “subgrid” motions have to be parametrized with formulas that cannot be validated, either because of space or time scale involved. I don’t know the theory that links the space of solutions between the two sets of equations; in fact these spaces cannot be equal because of different functional dimensionality of two sets of equations. Therefore, the model output is not a consequence of any natural theory but a product of truncation and imagination, especially on the long time scales.
More, the output of your imagination of primitive equations is not compared to anything, because observations (in this particular case, the radiative balance between SWin, SWout(albedo), and OLR) are not up to the spatial details nor resolution (and accuracy) that is required to compare and derive any definite conclusions. If these accurate observations did exist, there will be no question if there is any global imbalance due to added CO2 or not. If you know of any such measurements, please kindly post the reference.
James Sexton says:
“The problem stems from connotations. C, CO, and CO2 mean the same thing to different people.”
Yes, and those different people all seem to be in the warmist camp. To them, it’s all “carbon” if it has a C in it. We must watch our “carbon” footprint. If it’s exceeded, we must buy “carbon” credits to atone.
In a way I sort of agree with them. I think I’ll add to my after dinner carbon footprint with some C2H5OH.☺
Theo Goodwin: Bravo for you, Mr. Bancroft. Yes, this kind of input is most definitely needed.
There are a number of such half-stories regularly quoted by the supporters of AGW, which unfortunately go unchallenged or unremarked upon. A couple of years ago I got interested in global warming matters and started to dig into some of the standard AGW themes. One of these claims was that the Arctic icecap was melting and which usually came with figures from a genuinely authoritative source to back it up.
However, somewhat mysteriously, they never mentioned the Antarctic ice, which even to a layman would seem to be worth including in GW discussions as it is the largest icecap. This half of the story shows that the Antarctic ice sheet is in fact increasing, albeit slowly. This is something which needs to be widely acknowledged and perhaps even automatically referred to by the MSM on any melting ice related news, so that it can become an accepted counter to the semi-truths used by the AGW proponents.
James Sexton said:
“while “very few objects are feathers”, there are many that have the characteristics appropriate for Barry’s example; leafs, dandelion seeds, spider eggs, certain blades of grass, etc….”
I think the list must be expanded with the most important (and least studied) stuff like bacteria and plankton-generated DMS microparticles and other particulates that act as seeds of condensation and formation of clouds.
Smokey;
And does that increase your CH4 output?
If so, let me recommend activated charcoal (a mechanical mix of C and H2O, very appropriate!)
Edward Bancroft,
There is also the fact that the Antarctic has ≈90% of the planet’s ice. Therefore, a small increase in Antarctic ice cover offsets a 10x greater decrease in the Arctic.
Total planetary ice cover is normal, and is well within the parameters of past natural variability.
Brian H:
Last time I had a bean burrito it nearly triggered a tipping point.
Edward B.;
Since only land-bound ice can significantly accumulate, it is noteworthy that both Greenland and Antarctica are already bowl-shaped from the weight of the ice. This, of course, causes more ice to flow towards the center, increasing the weight and sinking the land further, which …
OMG! It’s runaway positive feedback! Eventually all the world’s water will be occupied in filling the great holes those sinking land masses are making in the crust!
The obvious solution is to hit the ice sheets there with a few dozen multi-megaton H-bombs to break up the ice before we hit a Tipping Point and All Is Lost.
Smokey says:
December 28, 2010 at 5:45 pm
In a way I sort of agree with them. I think I’ll add to my after dinner carbon footprint with some C2H5OH.☺
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Heh, already there with you, my friend.
Yeh, you’re right about the carbon and hating all that it involves. Its another manifestation of their autophobia. It must be horrid going through life projecting a self-loathing onto anything attached to the base of their formation.
James S.;
Their disorientation will be complete when it is ultimately (soon) accepted that CO2 is beneficial, and all the world’s governments switch to heavily subsidizing maximum output, e.g. by offering free coal-fired power-plant electric power to all, plus specifically requiring EVs to be powered by it. And encouraging concrete home construction so as much limestone as possible can be baked to free the CO2 it has stolen from the air, and …
LazyTeenager says:
December 28, 2010 at 4:10 pm
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.”
——————
So Barry, you mean that when certain climate skeptics claimed that the IPCC was exaggerating the certainty, those particular climate skeptics were lying.
So LT, do you now agree that ipcc Climate Science simply cannot predict future climate states, so that there actually is absolutely no future CAGW to predict or worry about?
But, hey, then go read the SPM4 to see the ipcc suddenly increase its certainty infinitely, from the TAR’s flat out impossibility of predicting CAGW “Climate Change” to a level of certainty which in fact even tries to convince us to commit suicide ‘before it’s too late’……or else we will all die from CAGW!
“Chris Clark says:
December 28, 2010 at 4:41 pm
As for pointing out to the MSM that the temperature/CO2 relation is logarithmic: they wouldn’t know what you were talking about.”
This may well be true. So if you plan on writing to your local paper on this issue, as I have done, mention that it is the same as the law of diminishing returns. Many more people would understand that.
cal, I recommend the online MODTRAN program (e.g. from U. Chicago) to understand why the troposphere profile still dominates the CO2 outgoing radiation as you double CO2. Basically, yes, the center of the band is radiating at the stratospheric temperature which doesn’t change much as you double CO2, as it is fairly isothermal in the lower stratosphere, so the decrease in OLR comes from the sides of the band which still radiate from the troposphere.
Barry Woods – the very real example of AGWScience gobbledegooking real science as your feather example is in its claims about the properties of CO2 re weight.
After several discussions and some some amount of exploration I found the reason why AGWScience says that CO2 is well-mixed in the atmosphere and so extrapolated, can stay up hundreds, even thousands, of years accumulating, and why those telling me this could not grasp that CO2 is heavier than air and so sinks through the atmosphere displacing air. They are using ideas from the ideal gas law and applying it to real gas molecules in our atmosphere.
The ideal gas is a fiction, it is imaginary (no doubt many here know how to use ideal gas laws in calculations, and can also no doubt explain it better than I), but they do not actually match real gas molecules, “real” is a technical term here to flag the difference in gas physics.
The ideal gas law quoted as ‘proof’ that CO2 is well-mixed and can stay up in the atmosphere says that molecules travel at extraordinary fast speeds through empty space bumping into each other and so mixing up ‘thoroughly’. Pointing out that this doesn’t apply to molecules under pressure and gravity and interactions of no avail, even with numerous examples (such as diagramatical description of how sound travels). The picture they have in their minds is of our atmosphere being empty space. Their physics teachers teach them that CO2 in our atmosphere acts like this ideal gas. Though they don’t dispute that CO2 is heavier than air, they don’t understand it.
I asked one such how CO2 could possibly rise up to mix in the air after it had pooled on the ground and without any work being done to move it since it was 1.5 times heavier than air, and was told that it would diffuse into the atmosphere as per ideal gas laws and become thoroughly mixed and could then not become separated (without work being done).
He taught the physics of gases, set exams in the subject – and said he would fail anyone who said CO2 didn’t act as an ideal gas in our atmosphere. He had absolutely no concept of what the air around us actually was. It has been lost to AGWScience.
By the end of that particular discussion I felt as if I had stepped through the looking glass with Alice.
Myrrh says:
I can pretty much assure you that the person you had the discussion with must have felt likewise.
All models are approximations. However, the ideal gas law is a very good…perhaps even excellent approximation…at atmospheric densities.
Do you have any evidence for your claim that the CO2 is not quite well-mixed in the atmosphere? We now have data from a variety of sites (at various elevations) as well as AIRS data…and while there was a lot of hullabaloo made with the AIRS data about the CO2 concentration not being completely uniform, the fact is that the differences from complete uniformity are irrelevant at the levels of accuracy with which we are currently able to consider.
By the way, I am not even sure that the best answer to your question about why CO2 doesn’t segregate is really the ideal gas law. I would say it comes more from kinetic theory or from statistical physics, at least the part about segregation under gravity. (E.g., one can presumably do a calculation of the entropy vs energy tradeoff for gases to mix vs segregating…I may try to think a little bit more about whether one could easily do this in a way that permits a quick-and-dirty estimate of what controls whether you are in the well-mixed or gravity-segregated regime).
p.s.
jt posted a link on tips and notes to an article about real air and the weather system in our dynamic world, http://chiefio.wordpress.com/2010/12/28/ignore-the-day-at-your-peril/
The moderator reply to Peter Offenhartz December 28 2010 4:10 pm contains a response to the idea that air is ‘well-mixed’. Here the claim is that air is well-mixed to 1,000 metres, which is a new one to me, I’ve only heard from AGW that all the atmosphere is well mixed, (and doesn’t layer).
Brian H says:
December 28, 2010 at 4:49 pm
Next time I’ll switch to argon – non-toxic and not a GHG. Just what we need!
Myrrh says:
December 28, 2010 at 7:41 pm
Myrrh,
In the troposphere convection will mix the air pretty thoroughly although not instantly.
Above that where there is no bulk transfer I have my doubts that molecular diffusion doesn’t have some part to play and that there isn’t some sort of CO2 concentration gradient in a one g field over a depth of 20Km or so when one component of the air is 1.5 times as heavy as the rest. In any case the CO2 in the stratosphere probably isn’t up to much IR absorption just like on Mars as the pressure broadening will be weak due to the low pressures. 🙂
@John Day
>> Conclusion: Even though CO2 is a powerful absorber of 15 micron radiation,
>> in isolation its contribution to “greenhouse warming” is negligible.”
@Mike Borgelt
> John, Lacis et al claim that this is due to the low pressure in the Martian
> atmosphere so there is little pressure broadening of the CO2 lines unlike Earth.
Yes, I’m aware of this claim in their “control knob” paper. The ‘pressure broadening’ is a observational artifact associated with absorption lines under pressure. At the molecular level, where all this photon absorption is going on it’s all about intermolecular collisions. Some of the absorbed energy may be spread by collisions, reseting the CO2 molecules.
There’s a lot of hand waving going on here. The Lacis paper makes this sound like a conjecture that needs to be proven.
Color me skeptical.
Just for the record, Galileo didn’t think a feather and a cannon ball would fall at the same rate. In “Two New Sciences” he spent great effort to explain terminal velocities in various fluids, and that indeed, if a cannon ball is fired faster than its terminal velocity, even with the barrel aimed straight at the ground, the ball will start slowing the instant it leaves the barrel. He also discussed the terminal velocities of cannon balls dropped in the ocean. His discussion of the feather was an attempt to make these effects clear.
Myrrh 12/28 7:41 PM
If you’re right, the atmosphere between ground level and about 1/4 mile up should be almost entirely CO2. Ascending further, we’d pass through many miles of nitrogen, and only then would we reach 5-6 miles of oxygen. So we wouldn’t be here to talk about it.
Rick Werme: and Moderator
.. “Don’t fall prey to the trace gas argument lest you forget that reducing CO2 by just a couple hundred ppm will kill plants or that 380 ppm of CO can’t possibly have an impact on people. (Exposure limits are 25-50 ppm, 400ppm for 4 hours can kill.)”….
I notice that I was not the only one who thought that Rick was still talking about CO2 above and that the CO was a typo.
Otherwise his post did not make any sense.
Come to think of it it did not make much sense whatever way you look at it.
It’s ironic that ‘simple physics’ is actually on the side of the sceptics. ‘Simple physics’ basically says that CO2-caused warming is a classic law of diminishing returns: if you double the amount of CO2 you will get around one degree of warming. To get another degree, you have to double the CO2 again, which will never happen.
In short, a doubling of CO2 from industrial levels, using only ‘simple physics’, will provide a modest and almost certainly beneficial warming. The logarithmic law provides this welcome warming, while at the same time ensuring that a warming of four or five degrees is completely impossible.
Of course, in reality the amount of warming is probably dominated by other factors, with CO2 having a negligible effect, as demonstrated by the ice cores. Quite likely we can thank our local star for the 20th century warming that we enjoyed. The bad news is that this particular star may be sulking so that our children may live in a colder world.
Yes, we do need to worry about climate change. But in the coming decades it will probably be global cooling that makes the headlines.
Chris