Guest Post by Willis Eschenbach
Figure 1. The Experimental Setup
I keep reading statements in various places about how it is indisputable “simple physics” that if we increase the amount of atmospheric CO2, it will inevitably warm the planet. Here’s a typical example:
In the hyperbolic language that has infested the debate, researchers have been accused of everything from ditching the scientific method to participating in a vast conspiracy. But the basic concepts of the greenhouse effect is a matter of simple physics and chemistry, and have been part of the scientific dialog for roughly a century.
Here’s another:
The important thing is that we know how greenhouse gases affect climate. It has even been predicted hundred years ago by Arrhenius. It is simple physics.
Unfortunately, while the physics is simple, the climate is far from simple. It is one of the more complex systems that we have ever studied. The climate is a tera-watt scale planetary sized heat engine. It is driven by both terrestrial and extra-terrestrial forcings, a number of which are unknown, and many of which are poorly understood and/or difficult to measure. It is inherently chaotic and turbulent, two conditions for which we have few mathematical tools.
The climate is composed of six major subsystems — atmosphere, ocean, cryosphere, lithosphere, biosphere, and electrosphere. All of these subsystems are imperfectly understood. Each of these subsystems has its own known and unknown internal and external forcings, feedbacks, resonances, and cyclical variations. In addition, each subsystem affects all of the other subsystems through a variety of known and unknown forcings and feedbacks.
Then there is the problem of scale. Climate has crucially important processes at physical scales from the molecular to the planetary and at temporal scales from milliseconds to millennia.
As a result of this almost unimaginable complexity, simple physics is simply inadequate to predict the effect of a change in one of the hundreds and hundreds of things that affect the climate. I will give two examples of why “simple physics” doesn’t work with the climate — a river, and a block of steel. I’ll start with a thought experiment with the block of steel.
Suppose that I want to find out about how temperature affects solids. I take a 75 kg block of steel, and I put the bottom end of it in a bucket of hot water. I duct tape a thermometer to the top end in the best experimental fashion, and I start recording how the temperature changes with time. At first, nothing happens. So I wait. And soon, the temperature of the other end of the block of steel starts rising. Hey, simple physics, right?
To verify my results, I try the experiment with a block of copper. I get the same result, the end of the block that’s not in the hot water soon begins to warm up. I try it with a block of glass, same thing. My tentative conclusion is that simple physics says that if you heat one end of a solid, the other end will eventually heat up as well.
So I look around for a final test. Not seeing anything obvious, I have a flash of insight. I weigh about 75 kg. So I sit with my feet in the bucket of hot water, put the thermometer in my mouth, and wait for my head to heat up. This experimental setup is shown in Figure 1 above.
After all, simple physics is my guideline, I know what’s going to happen, I just have to wait.
And wait … and wait …
As our thought experiment shows, simple physics may simply not work when applied to a complex system. The problem is that there are feedback mechanisms that negate the effect of the hot water on my cold toes. My body has a preferential temperature which is not set by the external forcings.
For a more nuanced view of what is happening, let’s consider the second example, a river. Again, a thought experiment.
I take a sheet of plywood, and I cover it with some earth. I tilt it up so it slopes from one edge to the other. For our thought experiment, we’ll imagine that this is a hill that goes down to the ocean.
I place a steel ball at the top edge of the earth-covered plywood, and I watch what happens. It rolls, as simple physics predicts, straight down to the lower edge. I try it with a wooden ball, and get the same result. I figure maybe it’s because of the shape of the object.
So I make a small wooden sled, and put it on the plywood. Again, it slides straight down to the ocean. I try it with a miniature steel shed, same result. It goes directly downhill to the ocean as well. Simple physics, understood by Isaac Newton.
As a final test, I take a hose and I start running some water down from the top edge of my hill to make a model river. To my surprise, although the model river starts straight down the hill, it soon starts to wander. Before long, it has formed a meandering stream, which changes its course with time. Sections of the river form long loops, the channel changes, loops are cut off, new channels form, and after while we get something like this:
Figure 2. Meanders, oxbow bends, and oxbow lakes in a river system. Note the old channels where the river used to run.
The most amazing part is that the process never stops. No matter how long we run the river experiment, the channel continues to change. What’s going on here?
Well, the first thing that we can conclude is that, just as in our experiment with the steel block, simple physics simply doesn’t work in this situation. Simple physics says that things roll straight downhill, and clearly, that ain’t happening here … it is obvious we need better tools to analyze the flow of the river.
Are there mathematical tools that we can use to understand this system? Yes, but they are not simple. The breakthrough came in the 1990’s, with the discovery by Adrian Bejan of the Constructal Law. The Constructal Law applies to all flow systems which are far from equilibrium, like a river or the climate.
It turns out that these types of flow systems are not passive systems which can take up any configuration. Instead, they actively strive to maximize some aspect of the system. For the river, as for the climate, the system strives to maximize the sum of the energy moved and the energy lost through turbulence. See the discussion of these principles here, here, here, and here. There is also a website devoted to various applications of the Constructal Law here.
There are several conclusions that we can make from the application of the Constructal Law to flow systems:
1. Any flow system far from equilibrium is not free to take up any form as the climate models assume. Instead, it has a preferential state which it works actively to approach.
2. This preferential state, however, is never achieved. Instead, the system constantly overshoots and undershoots that state, and does not settle down to one final form. The system never stops modifying its internal aspects to move towards the preferential state.
3. The results of changes in such a flow system are often counterintuitive. For example, suppose we want to shorten the river. Simple physics says it should be easy. So we cut through an oxbow bend, and it makes the river shorter … but only for a little while. Soon the river readjusts, and some other part of the river becomes longer. The length of the river is actively maintained by the system. Contrary to our simplistic assumptions, the length of the river is not changed by our actions.
So that’s the problem with “simple physics” and the climate. For example, simple physics predicts a simple linear relationship between the climate forcings and the temperature. People seriously believe that a change of X in the forcings will lead inevitably to a chance of A * X in the temperature. This is called the “climate sensitivity”, and is a fundamental assumption in the climate models. The IPCC says that if CO2 doubles, we will get a rise of around 3C in the global temperature. However, there is absolutely no evidence to support that claim, only computer models. But the models assume this relationship, so they cannot be used to establish the relationship.
However, as rivers clearly show, there is no such simple relationship in a flow system far from equilibrium. We can’t cut through an oxbow to shorten the river, it just lengthens elsewhere to maintain the same total length. Instead of being affected by a change in the forcings, the system sets its own preferential operating conditions (e.g. length, temperature, etc.) based on the natural constraints and flow possibilities and other parameters of the system.
Final conclusion? Because climate is a flow system far from equilibrium, it is ruled by the Constructal Law. As a result, there is no physics-based reason to assume that increasing CO2 will make a large difference to the global temperature, and the Constructal Law gives us reason to think that it may make no difference at all. In any case, regardless of Arrhenius, the “simple physics” relationship between CO2 and global temperature is something that we cannot simply assume to be true.
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The total human contribution to atmospheric CO2 is between 6 and 7%. If you cut out ALL human beings, ALL their factories, ALL their cows and ALL their transportation systems the effect would be trivial. Global warming would continue regardless. Aims of controlling the global temperature rise to below 2% are like King Canute telling the ocean to recede.
It’s depressing that the views of qualified scientists and engineers are lost in the clamour of people who know little or no science, such as show-biz personalities.
The “basic physics” argument is used to try and persuade people that the arguments such as “how can 0.03% of the atmosphere be important?” and “how can puny man have such an impact?” have an answer. Of course it doesn’t prove that it *will* have an impact.
But pointing out that believing the same causes always lead to the same effects is a logical fallacy doesn’t prove that it won’t have an impact either. My head doesn’t get warm if I put my feet in warm water because I sweat or radiate more. The evidence for the earth sweating or radiating more is currently thin.
Hank Henry (05:50:38) :
Someone pointed to this page on another thread, which may be what you are looking for in regard to what they mean by “fast” and “slow” feedbacks (see step 5).
M. Simon (05:13:33) :
Um, not really. If the numbers are integers, they are likely twos complement. No “formatting trick” necessary. They add and subtract just like any other numbers, that is their feature. For 32-bit signed integers, the range of possible values is +2^31-1 to -2^31. For 64-bit signed integers, the range of possible values is +2^63-1 to -2^63. Quite large.
If, however, the numbers are in floating point – a likely assumption, then there is a bit defined in the field to represent positive and negative. The floating point unit handles all floating point numbers. The standard is defined by IEEE 754, which describes the format though I would not refer to it as a trick. For the sake of brevity, I’ll just point out that the range 32-bit numbers is about +/-10^38 and of 64-bit floating point numbers is +/-10^308.
While this may be true, it realistically only applies to integer mathematics. An overflow in a single precision (32-bit) floating point is unlikely since the value would need to be quite large. In double precision (64-bit), an overflow is much more unlikely and would clearly indicate some other problem (why would you need any number as large as 10^308?). In either case, it should not result in a change from positive to negative (it depends on how the sign bit is handled when the overflow bit is set).
Technically, most computers also have mechanisms to deal with overflow, so it is impossible to say what will happen without knowing their specific processor. There might not be a rollover from positive to negative, but as I noted, that’s probably immaterial anyway.
Mark
Par5: “In the 1800’s, the ‘consensus’ was that the sun was made of coal….. if the sun is made of coal, then the earth could not be more than 10,000 yrs old…”
Thanks for your reply. I will continue to try to find a reference as to Arrhenius’ own thoughts on these things. As you know, he lived until 1927 and studied and taught in a variety of scientific areas. As early as the 1860s Kelvin offered “proof” of a much older earth. Primitive, but at least moved thinking into the 10s of million years range.
An amusing item from the wiki entry on Arrhenius: “For the rest of his life, he would be a member of the Nobel Committee on Physics and a de facto member of the Nobel Committee on Chemistry. He used his positions to arrange prizes for his friends (Jacobus van’t Hoff, Wilhelm Ostwald, Theodore Richards) and to attempt to deny them to his enemies (Paul Ehrlich, Walther Nernst).”
Sound familiar?
Sorry for straying so far OT.
M. Simon (10:11:58) :
True, but for a different reason. Op-amps have a fixed gain-bandwidth product so a larger gain factor necessarily implies lower frequency operation. What Bart is referring to is a slightly different effect.
Mark
M. Simon (06:16:10) :
“‘The temperature of the high CO2 is colder than the temperature of the surface because of the pressure difference (lower pressure means colder).’
You were doing well until you got to this point. You can have a low pressure gas with very high temperatures. It is done all the time in plasma physics.”
Off course it is possible that a low pressure gas is hot, but in our troposphere this is not the case. You can read more about this here: http://en.wikipedia.org/wiki/Troposphere#Temperature
Thank you Willis. It is clear that we ought to regard climate science more as non-trivial and/or theoretically impossible to understand than as settled science.
Just some food for thought, hopefully not OT: if all a river did was “follow the path of least resistance” and was not a complex system striving to maintain some form of equilibrium, the Army Corps of Engineers would not be having so much trouble, historically, with its levees on the Mississippi River.
Since most TV and print news spots on global warming always show smokestacks spewing copious clouds of condensing water vapor into the atmosphere, perhaps the next thing King Canute might try would be controlling anthropogenic H2O…
sHx said on The Unbearable Complexity of Climate
December 27, 2009 at 7:42 pm
‘”ThinkingBeing (13:50:32) : But I’m not going to argue the validity of the models on these pages with anyone here. This is the land of zealots who have already made up their minds, then, with their minds closed, have chosen to very heroically label themselves as “skeptics.” So there’s no way to educate them, and no point in trying.” I am a layman and I am fairly new to the AGW debate.’
I couldn’t agree more. I too am a layman (in climate science) and as an intelligent sceptic on AGW (and a number of other issues) I appreciate the chance to scrutinise all sides of an argument and weigh up the arguments and the science in an open-minded way. I have been teaching students to do this all my life. It has been a true delight over the past year to be a regular visitor to WUWT and to listen in to some truly magnificent socratic dialogues and hear some real experts share their knowledge and expertise with such grace and generosity.
It was a shock when ‘ThinkingBeing’ showed up like a hired attack-dog and displayed his arrogance and blinkered approach. See above for just a small example.
It is clear that the earth’s climate must be studied in the context of deterministic chaotic systems. It is a quintessentially Complex Adaptive System and the positive and negtative feedbacks need to be taken into consideration. Its key controlling parameter must surely be the heat of the sun. GHG’s may play a role but very much on the margins.
Furthermore, the climategate scandal and other ways in which the science has been manipulated (let’s put it no stronger than that) over the decades, will come to represent one of the great crises in science and its established modus operandi in modern times. WUWT has provided a refuge for those driven out of the MSM and the now tainted peer-review world.
Thanks again to Anthony and all at WUWT for providing such a wonderful resource to all and sundry, whether expert or novice – and a tone of openness and seriousness of enquiry. You are a true “city on a hill”.
Allan M R MacRae (01:31:52) :
“See the 15fps AIRS data animation of global CO2 at
http://svs.gsfc.nasa.gov/vis/a000000/a003500/a003562/carbonDioxideSequence2002_2008_at15fps.mp4”
This demonstration looked plain wrong to me, but I couldn’t figure it out. It has take me a couple of days (and two sleeps) to get it.
The color coding used to depict the CO2 level, is the opposite of the convention used to depict the frequency spectrum, where infrared is low, and ultraviolet is high.
Somebody has decided to depict the scale in reverse to subliminally suggest that more CO2 will be hot (red), and less will be cold (violet).
I guess following engineering conventions was not politically acceptable … (sigh)
Steve Milesworthy (10:40:31), you raise a valid point, viz:
See my article on WUWT here for some evidence about how the earth responds to changing forcings. The reason that the evidence is thin is that people have bought into the “simple physics” mantra, so nobody is looking for evidence because “the science is settled™ ” …
“Robin (11:47:17) :
[…]
It was a shock when ‘ThinkingBeing’ showed up like a hired attack-dog and displayed his arrogance and blinkered approach. See above for just a small example.”
You’re not on forums a lot it seems 😉
DirkH said on The Unbearable Complexity of Climate
December 27, 2009 at 7:42 pm
“Robin (11:47:17) :
[…]
It was a shock when ‘ThinkingBeing’ showed up like a hired attack-dog and displayed his arrogance and blinkered approach. See above for just a small example.”
You’re not on forums a lot it seems ;-)”
‘Spose not. Thanks for the advice, but he got the treatment he deserved and hopefully won’t show up here again. All heat and no light…
Pippa Biggs (02:07:43) :
Folks who specialize in risk management will tell you that planning for “the worst case scenario” is probably the worst thing you can do. It leads to all sorts of distortions of thinking.
The worst case scenario for a building may be a threat to its structural integrity, from fire, earthquake, terrorist attack, et al. So all of the thought goes into how you can evacuate a large number of people in the shortest possible time, without panic.
It is good to know how to do those things, but there is an inbuilt assumption that planning for the worst case will also include all of the other possible scenarios, most of which will be more likely. Knowing how to evacuate a building does not really protect you from the risk of somebody, on the floor above, turning on a sprinkler system directly over your computer room, for example.
It is better to plan for a set of the “most probable scenarios”, than a single worst case.
I see a lot of the discussions around the IPCC framework being centered around a doubling of CO2. But I do not see much explanation of why an arbitrary doubling is considered likely, or even plausible. I therefore assume that a doubling is a worst case proposed by somebody as a discussion point, at some time in the misty past.
Of course, worst case scenarios do have an effect of frightening little children and politicians, so they do have some merit in conditioning the next generation to accept the current belief system for the future, and in mobilizing political action (and funding) now.
The world has been this hot before, and CO2 levels have been this high before, and the planet as survived and even prospered. But, as you rightly point out, there is a major difference in the relative size of the human population, and that is the real elephant in the room.
If you follow the worst case scenario logic to its conclusion, and you genuinely feel strongly enough about doing what you can to save the planet, then one conscious choice you will need to face, is whether or not you should have children.
Despite the impossibility to model the exact path by which water will flow down hill, one came safely presume that the water will finally end up at the same spot:
And one would presume entirely wrongly. The Waikato river changed which coast it flowed out of some time back, although that may have been something external.
The limans on the Black Sea are a large scale obvious example of rivers changing course without external pressure.
In general large rivers flowing out across flat land form large deltas, and the main channel will change dramatically over time. Have a look at the course of the Volga or Nile some time.
Gasses are not blackbodies and will only radiate/absorb certain spectra. O2 is not active in the infrared, so it does not radiate/absorb infrared light. CO2 does radiate/absorb infrared light, that is why it is called a greenhouse gas.
The temperature of the high CO2 is colder than the temperature of the surface because of the pressure difference (lower pressure means colder).
This still does not answer the question MrAce.
Why is cold CO2 somehow more effective as a greenhouse gas than warm CO2? Why does it, allegedly, matter that CO2 is in the outer atmosphere?
That is the allegation: that CO2 in the outer atmosphere is cold, and therefore radiates away less heat. Note, not absorbs more heat to radiate back as a greenhouse gas, but actually radiates out less heat – at least that what they seem to be saying, which is why I am confused.
They keep citing that radiation is to the fourth power with temperature, which seems to have nothing at all to do with the greenhouse effect.
Because homonuclear diatomics (like O2) don’t have a dipole!
You can quickly turn up papers like: “Near-infrared absorption spectroscopy of oxygen and nitrogen gas mixtures” and “Fine structure of the Infrared Atmospheric Oxygen Bands”. These suggest Oxygen does absorb in the IR.
I think it might be because Oxygen does have a magnetic dipole. There being two unpaired electrons.
And where there is atmospheric oxygen there is ozone, which also absorbs in the IR.
excellent analogies which can be used to communicate the problems of modern climate research to the common folk!
The physics based reason is very simple to understand and would require an act of God to alter
What was that you were saying back at the start Willis? 🙂
Rereke Whakaaro (13:34:01) :
“But I do not see much explanation of why an arbitrary doubling is considered likely, or even plausible.”
What I am going to tell you may seem fantastic, but this is their thinking, as best I have been able to ascertain. Naturally produced CO2 is readily absorbed by the ocean, but the ocean does not like anthropogenic CO2 and refuses to absorb it as readily. This, despite that fact that the two molecules, except for some slight differences in isotopic distribution, are identical. It’s all dressed up in some unseemly gobbledy-goop about “buffer factors” but, in essence, what it means is that anthropogenic and natural CO2 absorption dynamics can be decoupled, and while natural CO2 is rapidly absorbed into the oceans, absorption of anthropogenic CO2 has a much longer time constant.
As a result, when they dump all of the available carbon reservoir into the atmosphere in a short time relative to the hypothesized anthropogenic time constant, it accumulates in the atmosphere, easily leading to a doubling or even quadrupling atmospheric concentration (and, don’t be thinking that the idea of all that CO2 going into the atmosphere and not the ocean is in any way contradictory of the claim that anthropogenic CO2 is also leading to acidification of the ocean – it’s magical CO2 which can be in both places at once!).
It’s insane. But, the skeptic camp did not get into gear fast enough to prevent it from becoming established dogma and, it is very difficult to turn the tide when the argument (that the feedback mechanisms must treat both natural and anthropogenic CO2 the same, and this necessarily contradicts the claim that the rise in CO2 is purely anthropogenic) is subtle, and CO2 levels have inarguably been rising coincident with industrialization. So, the skeptic camp tends to focus on lower hanging fruit, such as the effect of clouds, which even the IPCC admits is an Achilles heel in the climate models.
nanny_govt_sucks (00:17:10) :
Kadaka,
If a particular industry has an expected rate of return of 8%, and the banks are paying 9%, people would rather put their money in the bank.
I think that is a free society’s way of saying that the industry is no longer viable. High interest rates will clean up a lot of the inefficient and non-viable industries, making more capital available for the efficient and viable ones. Again, not necessarily “positive” nor “negative”, but a necessary part of an efficient economy.
Nah. High interest rates limit capital. If an industry historically has a certain profit margin, and the banks are charging too high of an interest rate for both the loan interest to be paid and sufficient profit to be generated, then it costs more to access that source of capital funding than it is worth. Essentially that capital is non-existent.
Industry already has a very good means of becoming more efficient, they have to generate profits for investors. People will put their money where they will get the best return, limited by the amount of risk they are willing to accept.
When you speak about cleaning out inefficient and non-viable industries, remember that “cleaning out” involves jobs being lost. Then to pay for the assorted welfare-type spending to help those unemployed, taxes get raised, which lowers profit margins, which makes other industries fall into the “inefficient and non-viable” category, which leads to… Nations can also resort to deficit spending and issuing debt, which then sucks up investment money that could have been placed in banks or invested in industry.
And don’t think other more-efficient more-viable ones will spring up to replace the industries that are lost and to hire those workers. I have seen how America was supposed to transform from a manufacturing-based economy to a services-based one. But with a world economy, services could be found cheaper elsewhere. Our standard of living still seems high, because we are receiving dirt-cheap imports from China and other places. Yet there has been a great decline, a loss of wealth.
And as we keep finding out, we can still have the absolute most efficient operations in the world, without a cent to squeeze out anywhere, and still with our taxes, regulations, and expected wages, we cannot compete in the world market with those whose operations are amazingly inefficient but those three things are so low they can still always beat us on price.
By the way, with your “free society” efficient economics, how are you feeling about your morals? Because, in effect when not in reality, our standard of living is being maintained by slavery. American politicians don’t complain about human rights abuses and treatment of workers in China and other places, because we need the cheap goods. We have also gotten rid of several “inefficient and non-viable” industries and now depend on those other countries for our supplies.
High interest rates lead to (virtual) slavery. Think about that.
“Bart (15:26:14) :
[…]
What I am going to tell you may seem fantastic, but this is their thinking, as best I have been able to ascertain. ”
I just found this wiki , it explains the dogmatic position:
http://www.waterencyclopedia.com/Bi-Ca/Carbon-Dioxide-in-the-Ocean-and-Atmosphere.html
And guess what you don’t find in that wiki? The word Segalstad.
They’re all crazy. They just ignore everything that doesn’t fit. They don’t even need to mention the contrary opinion. All across the entire pseudoscience. They’re all whacked.
Mooloo (14:16:48) :
I believe, and could be wrong, that is actually cold CO2 will transfer the radiation energy, not heat per se, away at a slower rate. Of course, if there is or has been an effect, I would expect it to happen when the CO2 begins absorbing the extra IR (when added to the atmosphere), and I don’t see any reason to believe otherwise. That is why current weather observations are a problem for model-thumping believers.
Of course, if CO2 loses energy in lower atmosphere collisions, then I also don’t see how extra energy makes it to the upper atmosphere. I would think that the hotter CO2 have more of a tendency to rise and the cooler CO2 would have more of a tendency to sink, generally. So I don’t really see how it would make much difference.