This simple visual analogy that Ron House has designed can help readers not familiar with a contentious atmospheric modeling issue get a primer on the it. While not a perfect analogy (and by definition analogies often aren’t) it does help convey an important point: the predicted red spot has not appeared. For the more technically inclined, or for those wanting more, Steve McIntyre posted an interesting discussion at Climate Audit. – Anthony
Guest Post by Ron House July 29, 2009
Let’s say it’s a cold night and Fred climbs into bed:
(A) Fred in bed.
Will Fred use a blanket to keep warm? If so, the air will heat up close to Fred because his body warms the air and the blanket prevents it from moving away. On the other hand, as the night progresses, the air beyond the blanket will cool:
(B) With a blanket, the warm air collecting around Fred warms him up.
In the picture, the “+” signs show air that becomes warmer, and the “-” signs air that becomes cooler.
Now what if Fred (forgetful Fred) didn’t use a blanket? The warm air escapes and tends to rise (warm air being less dense than cold air):
(C) With no blanket, warm air escapes and Fred shivers.
Poor Fred gets colder as the night wears on. But now we come to the point of the exercise: How do we know whether Fred used, or did not use, a blanket?
“Easy,” you say: “Take a look!” But let’s suppose that Fred is a very light sleeper, we dare not put on the light, so there’s no way we can see if there’s a blanket. But—surprise!—we just happen to have an infra-red scanner that can tell us the temperature of the air at various spots throughout the room. Depending on whether Fred uses a blanket, the temperature change in the room follows one of the two characteristic patterns we saw above; so if we check where the air gets colder and where it gets warmer as the night wears on, we know, for a fact, whether or not Fred used a blanket, even without being able to see it. If Fred did use a blanket, our scanner should show results like this (note how we can’t see the blanket, but we can be sure that it is there):
(D) Warm air collects in a contained region, so there must be a blanket.
On the other hand, if he does not use a blanket, we will see the temperature change in a pattern something like this:
(E) Warm air escapes upwards, so we are sure there is no blanket.
Once again, there is no doubt at all what is going on. In science, nothing is absolutely certain, but depending on which temperature pattern develops, we can be very, very sure indeed of the answer to the question: Did Fred use a blanket?
Now we can turn to the global warming question, whether the Earth is surrounded by a ‘blanket’ of anthropogenic (human-generated) greenhouse gas stoking up the temperature of the planet. The physics of a real blanket (as with Fred in the fable above) and a gaseous ‘blanket’ around the Earth differ, but just the same, different heat dissipation (or retention) processes will result in different characteristic patterns of temperature change. Just as Fred will be surrounded by something roughly resembling one of two quite different patterns of air temperatures, so likewise will temperature changes around the Earth have a quite definite pattern, depending on which climate theory is right. Scientists whose paycheck does not depend on agreeing with global warming alarmism will all agree with this simple statement. It’s part of the basic skill of having a ‘nose’ for physics.
What, then, are our main competing climate theories? The IPCC’s reports are based on results from a collection of climate computer models; they have nothing else. These are simply computer programs that, in essence, contain a computerised version of the assumptions and beliefs of the climate modeller as to how the climate of the planet works. Whether these assumptions are well-founded is another question, but the key point is that whatever these assumptions may be, when the climate model is run, it generates its ‘predictions’ by calculation of hypothetical futures for the behaviour of the atmosphere. These ‘futures’ contain, as an essential element, predictions of the changes of atmospheric temperatures at various heights above the planet and the various latitudes all the way from south pole to north pole.
The indisputable fact about these atmospheric temperature predictions is that if the pattern doesn’t happen, the model is wrong. Just as Fred won’t warm up if he isn’t surrounded by warm air, likewise the effects on the Earth of global warming cannot happen if the cause of the warming —the warm air—isn’t there.
So now we come to the graphs that clinch the matter. All global warming models predict some sort of developing ‘hotspot’ in the atmosphere above the tropics. Here is the graph for one of the models, but they all look roughly similar:
(F) Model predicts air above the tropics heats up. from the NIPCC Report p. 107
This picture shows the air from 75 degrees north to 75 degrees south (the equator in the middle) and up to 30 km above the Earth. We can think of this air pattern as corresponding to the pattern in Fred’s bedroom when Fred used a blanket: although the actual mechanism is different, something is ‘keeping the heat in’, so to speak. Just as we did with Fred in bed, we can compare reality with this picture. Is the heat in the real atmosphere doing what the model predicts? Here is the temperature trend in the real world:
(G) Real world trend develops no hotspot. from the NIPCC Report p. 106
What have we actually proved here? Well, proved, without possibility of error, nothing, of course: no question at all about the real world ever has a complete perfect proof as an answer, so don’t be misled if someone says the world still might be heating due to CO2 despite the absence of the warm spot that is supposed to do the warming. Of course anything might be happening; but how likely is it? Well how likely is it that Fred has a blanket, but the air around him is getting colder just as if he had no blanket, and yet Fred is warming up despite that? The two questions have the same answer: not very.
Yet surprisingly, some proponents of global warming alarmism actually resort to this very strategy. “True,” they say, “the hot spot isn’t developing. But that is because the heat is being stored up elsewhere—it’s “in the pipeline”—and one day it will burst forth with even greater severity and vengeance.”
What can we make of that claim? Well, thinking back to Fred again, it amounts to this: We use our temperature probe in Fred’s darkened bedroom and we see a pattern like that in (E) above, corresponding to no blanket: Fred should be freezing! But actually, the heat has all gone into Fred’s body, despite the complete absence of the hot air which is the mechanism for making it do so. In other words, Fred got warmer by disobeying the second law of thermodynamics—in other words, by magic. Likewise, if someone says heat is being secretly stored somewhere by global warming, despite the absence of the very mechanism that does the warming, they are saying global warming is happening by magic. That is the harsh truth of the matter.
One thing I have learned whilst studying the global warming question is that, like many other physical systems, the climate is constrained by limits that can be understood by any intelligent person willing to learn some simple physics. The ‘hotspot’ is one of them. Anyone talking down to you and telling you you have to take the word of some mythical ‘consensus’ of ‘experts’ is trying to hoodwink you.
Let’s say it’s a cold night and Fred climbs into bed:
(A) Fred in bed.
Will Fred use a blanket to keep warm? If so, the air will heat up close to Fred because his body warms the air and the blanket prevents it from moving away. On the other hand, as the night progresses, the air beyond the blanket will cool:
(B) With a blanket, the warm air collecting around Fred warms him up.
In the picture, the “+” signs show air that becomes warmer, and the “-” signs air that becomes cooler.
Now what if Fred (forgetful Fred) didn’t use a blanket? The warm air escapes and tends to rise (warm air being less dense than cold air):
(C) With no blanket, warm air escapes and Fred shivers.
Poor Fred gets colder as the night wears on. But now we come to the point of the exercise: How do we know whether Fred used, or did not use, a blanket?
“Easy,” you say: “Take a look!” But let’s suppose that Fred is a very light sleeper, we dare not put on the light, so there’s no way we can see if there’s a blanket. But—surprise!—we just happen to have an infra-red scanner that can tell us the temperature of the air at various spots throughout the room. Depending on whether Fred uses a blanket, the temperature change in the room follows one of the two characteristic patterns we saw above; so if we check where the air gets colder and where it gets warmer as the night wears on, we know, for a fact, whether or not Fred used a blanket, even without being able to see it. If Fred did use a blanket, our scanner should show results like this (note how we can’t see the blanket, but we can be sure that it is there):
(D) Warm air collects in a contained region, so there must be a blanket.
On the other hand, if he does not use a blanket, we will see the temperature change in a pattern something like this:
(E) Warm air escapes upwards, so we are sure there is no blanket.
Once again, there is no doubt at all what is going on. In science, nothing is absolutely certain, but depending on which temperature pattern develops, we can be very, very sure indeed of the answer to the question: Did Fred use a blanket?
Now we can turn to the global warming question, whether the Earth is surrounded by a ‘blanket’ of anthropogenic (human-generated) greenhouse gas stoking up the temperature of the planet. The physics of a real blanket (as with Fred in the fable above) and a gaseous ‘blanket’ around the Earth differ, but just the same, different heat dissipation (or retention) processes will result in different characteristic patterns of temperature change. Just as Fred will be surrounded by something roughly resembling one of two quite different patterns of air temperatures, so likewise will temperature changes around the Earth have a quite definite pattern, depending on which climate theory is right. Scientists whose paycheck does not depend on agreeing with global warming alarmism will all agree with this simple statement. It’s part of the basic skill of having a ‘nose’ for physics.
What, then, are our main competing climate theories? The IPCC’s reports are based on results from a collection of climate computer models; they have nothing else. These are simply computer programs that, in essence, contain a computerised version of the assumptions and beliefs of the climate modeller as to how the climate of the planet works. Whether these assumptions are well-founded is another question, but the key point is that whatever these assumptions may be, when the climate model is run, it generates its ‘predictions’ by calculation of hypothetical futures for the behaviour of the atmosphere. These ‘futures’ contain, as an essential element, predictions of the changes of atmospheric temperatures at various heights above the planet and the various latitudes all the way from south pole to north pole.
The indisputable fact about these atmospheric temperature predictions is that if the pattern doesn’t happen, the model is wrong. Just as Fred won’t warm up if he isn’t surrounded by warm air, likewise the effects on the Earth of global warming cannot happen if the cause of the warming —the warm air—isn’t there.
So now we come to the graphs that clinch the matter. All global warming models predict some sort of developing ‘hotspot’ in the atmosphere above the tropics. Here is the graph for one of the models, but they all look roughly similar:
(F) Model predicts air above the tropics heats up. from the NIPCC Report p. 107
This picture shows the air from 75 degrees north to 75 degrees south (the equator in the middle) and up to 30 km above the Earth. We can think of this air pattern as corresponding to the pattern in Fred’s bedroom when Fred used a blanket: although the actual mechanism is different, something is ‘keeping the heat in’, so to speak. Just as we did with Fred in bed, we can compare reality with this picture. Is the heat in the real atmosphere doing what the model predicts? Here is the temperature trend in the real world:
(G) Real world trend develops no hotspot. from the NIPCC Report p. 106
What have we actually proved here? Well, proved, without possibility of error, nothing, of course: no question at all about the real world ever has a complete perfect proof as an answer, so don’t be misled if someone says the world still might be heating due to CO2 despite the absence of the warm spot that is supposed to do the warming. Of course anything might be happening; but how likely is it? Well how likely is it that Fred has a blanket, but the air around him is getting colder just as if he had no blanket, and yet Fred is warming up despite that? The two questions have the same answer: not very.
Yet surprisingly, some proponents of global warming alarmism actually resort to this very strategy. “True,” they say, “the hot spot isn’t developing. But that is because the heat is being stored up elsewhere—it’s “in the pipeline”—and one day it will burst forth with even greater severity and vengeance.”
What can we make of that claim? Well, thinking back to Fred again, it amounts to this: We use our temperature probe in Fred’s darkened bedroom and we see a pattern like that in (E) above, corresponding to no blanket: Fred should be freezing! But actually, the heat has all gone into Fred’s body, despite the complete absence of the hot air which is the mechanism for making it do so. In other words, Fred got warmer by disobeying the second law of thermodynamics—in other words, by magic. Likewise, if someone says heat is being secretly stored somewhere by global warming, despite the absence of the very mechanism that does the warming, they are saying global warming is happening by magic. That is the harsh truth of the matter.
One thing I have learned whilst studying the global warming question is that, like many other physical systems, the climate is constrained by limits that can be understood by any intelligent person willing to learn some simple physics. The ‘hotspot’ is one of them. Anyone talking down to you and telling you you have to take the word of some mythical ‘consensus’ of ‘experts’ is trying to hoodwink you.
Curiousgeorge (04:54:57) :
people who make the decisions want certainty
Are you sure?. Is it not the contrary?
I can accept it happens in private businesses but neither in any government nor in show business whatsoever. If it scares, distracts or even fools, or…whatever , it’s OK
The difference is, Fred’s body generates quite a lot of heat of its own, regardless how it disippates when he sleeps. The earth however radiates a tiny fraction of the heat budget – some 1% of the “heat budget”. Even if c02 could trap longwave radiation, there’s precious little of it to hold onto.
http://nov55.com/41r.html
“The IPCC’s reports are based on results from a collection of climate computer models; they have nothing else”
That laughable statement tells me straight away that you’ve never read any IPCC reports.
“”” Phil M (04:27:58) :
Equally, I don’t think there are many people who dispute that CO2 in general has a ‘warming’ or ‘blanketing’ effect, and without CO2 in the atmosphere, the earth would be considerably colder. “””
Solar energy arrives at earth at a roughly constant rate; 1366 W/m^2, which would continuously increase the temperature of the earth; BUT ! the earth also radiates energy in the infra-red spectrum, which could escape from the planet in one millisecond. If a “blanket” mechanism slows the exit of the IR radiation; but does not affect the incoming solar energy, then the delay in the exit, will result in more incoming solar energy, so the temperature would rise by some increment; to re-establish an “equilibrium” exit rate. (unless something else happens)
One of the something elses that may happen would be simply an adjustment to the amount of global cloud cover. An increase in cloud cover would block more sunlight and that could compensate for the blanket. So it is not a foregone conclusion that the existence of a blanket results in significant temperature rise.
Nor is it necessary that the earth be much colder in the absence of CO2. Water vapor is a much more powerful “blanket” gas than CO2, and there is plenty of water to substitute for any deficiency in CO2 blanketing.
Absent the CO2 and the water would simply adjust the water vapor and cloud cover to adjust the temperature. The earth’s temperature is primaril;y a direct result of the the physical properties of H2O. Other variables may change; but so long as the water is there in the oceans; and forms clouds in the sky, the temperature can’t mpove out of a fairly small range; dependent on the properties of water.
Kaboom, what nonsense you speak.
Infra-red travels at the speed of light; always does; CO2 doesn’t change this.
Polar bears are doing just fine, more around today than for the previous 50 years.
You’re quoting the NIPCC who utilise out-of-date information. The raw radio sonde data contain numerous (until recently) uncharacterised errors and discrepancies due to different methodologies. I would recommend familiarising yourself with the latest available literature which shows that model vs radio sonde discrepancies have largely been resolved. Also, there are other datasets available to look at trop. trop. temperatures: RSS and UAH. Your analysis is simply too narrow given the well known discrepancies in the CRU trop. trop. radio sonde product.
http://earth.geology.yale.edu/~sherwood/sondeanal.pdf
http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2F2008JCLI2287.1
http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2F2008JCLI1929.1
https://publicaffairs.llnl.gov/news/news_releases/2008/NR-08-10-05-article.pdf
Well, there IS a blanket effect, but it’s much less pronounced when the blanket (water vapor) is much thinner, as it is in deserts.
Kum Dollison (08:04:03) : “Sit around and talk. Sit around and talk. Hypothsize. Theorize. Anything to keep the money flowing. But, NO Experiments.
You want MY ‘vote?’ Show me. Do an Experiment.”
Well, that’s just the problem, isn’t it? We can do experiments (add carbon dioxide to the atmosphere, clear a jungle, vary the sun a bit, blow the occasional volcano, pour soot into the air, move the continents), but we can’t do controlled experiments, e.g. build a hundred earths and change one thing on each.
Climate science isn’t really an experimental science; this situation is known as “job security”. 🙂
P Wilson (10:59:06)
‘The earth however radiates a tiny fraction of the heat budget – some 1% of the “heat budget”‘.
Sorry, but as far as I understand the situation, the Earth is an object in space receiving energy from the Sun. As with any other body, the Earth will heat up until it’s temperature causes it to radiate the same amount of energy into space and an equilibrium is achieved.
What is this ‘heat budget’?
Sorry to be so combative – must be something I’ve eaten…
How would ITCZ cu-nims affect this predicted hot-spot??
Can we repeat this analogy with Bill, Sid and Joe – so we have more data?
Colin Aldridge (09:52:54) :
Please don’t put posts like this on WUWT. The blanket analogy is simple BUT misleading and wrong and does not reflect well on a website that usually publishes decent and thoughful comments on science.
The lack of a hotspot does indeed show that the models are failing to model the real world with accuracy but this doesn’t prove anything about AGW .. it just shows the models are bad models.
But the models are one of the key aspects to AGW. If the theory is incorrect, how likely is it that GHG’s are the cause of recent warming? Admittedly, this is hard to gauge. But it does show us that the experts really don’t know what they are talking about.
““Green House Gases” do not do that, so please explain what they do do, with enough physics so I can check your work? Thanks.”
Happy to oblige.
The basic mechanism is described in Soden and Held [1], which was cited by the IPCC TAR (iirc). It is a combination of two effects – that its temperature changes when you compress or decompress a gas, and that equilibrium occurs when the heat input from the sun equals the heat output from the average altitude at which the atmosphere radiates to space.
Air pressure decreases with altitude, which means that so long as convection drives the rise and fall of air, it will be compressed and decompressed, resulting in a vertical temperature gradient in which it is warmer at the bottom than the top. Everybody knows that hot air rises, so it at first seems surprising that mountaintops are cold. It’s called the adiabatic lapse rate, and is standard physics that can be found in many textbooks.
The other effect is that the radiated heat increases with temperature, so if there is a heat input, the temperature will rise until it reaches the point where the heat emitted from the radiating surface exactly equals the input. But because of greenhouse gases – mainly water vapour – this is not the solid surface, but a foggy one extending throughout the lower troposphere, averaging out at about 4 km up. It is therefore the point 4 km up that settles out at the radiative equilibrium temperature, and then the air above and below it is respectively cooler and warmer because of the moist adiabatic lapse rate.
This is important. The surface is not warmer because heat is “trapped”. The warming mechanism is pressure, not absorption. And more greenhouse gases mean a thicker layer of IR-opaque ‘fog’, a higher average emission altitude, and therefore a greater pressure difference between this altitude and the surface.
And the check on the physics is that the atmosphere above the average emission altitude is colder! The temperature at the top of the troposphere drops to -54 C. There is no way to explain that with a “blanket” model.
Everybody gets the explanation wrong. (Which is positively shocking after 20 years at the top of the apocalypse charts!) I don’t expect anyone to start getting it right now as a result of me explaining it. 🙂
[1] Water Vapor Feedback and Global Warming, Annu. Rev. Energy Environ. 2000. 25:441-75.
In the case of AGW, all the Global Climate Models(GCMs) and the AGW CO2 theory predicts that there should be a measurable hotspot in the upper troposphere. Observations from satellites and weather balloons have been made, and no hotspot has been found.
That about right?
In a less politicized field, this would have been the end of it. If it weren’t for the hoaxer’s grant money, the real scientists would have long moved on.
The law of conservation of energy is certainly taking a beating in this post. Having lasted a couple of centuries, however, it will probably survive the present onslaught.
George E. Smith (11:17:31)
‘Solar energy arrives at earth at a roughly constant rate; 1366 W/m^2, which would continuously increase the temperature of the earth; BUT ! the earth also radiates energy in the infra-red spectrum…’
[At a large range of frequencies, not just IR]
‘…which could escape from the planet in one millisecond.’
[Let’s let that pass…]
‘If a “blanket” mechanism slows the exit of the IR radiation; but does not affect the incoming solar energy, then the delay in the exit, will result in more incoming solar energy, so the temperature would rise by some increment; to re-establish an “equilibrium” exit rate. (unless something else happens)…’
How does this blanket ‘slow anything’? If molecules in the atmosphere absorb energy their energy state – i.e. temperature is raised. They are then more likely to emit energy in some form.
Considered as a body, the Earth is thermodynamically the sum of the solid bits, the wet patches and the gassy envelope. The ‘blanket’ behaves just as thermodynamically as the Earth. To return to the inappropriate analogy in the original post, it is true that the blanket stops warm air convecting away from Fred during the night, but the blanket itself warms up and radiates and conducts heat to the outside. If Fred were not generating his own heat, he would soon return to ambient temperature, with or without the blanket, as any ‘CSI’ viewer will tell you. If you wrap a blanket round a rock, it’s temperature won’t rise.
Don’t forget: the hottest bit of the atmosphere is the thermosphere – on the edges of space.
Colin Aldridge (09:52:54). Blankets… hear, hear!
… its temperature … sorry.
Perhaps the kind moderator will correct it!
I didn’t have time to read all the comments, but it seems like a lot of you missed the point: If the models predict something and it’s not there, then the models are wrong.
Fred & a blanket (or not) is just a way of making the point.
John Finn (04:37:31) :
You and I both know that the( MSM and Joe the Citizen) are going to buy Fred in Bed over adiabatic time-lapse rate feedback.
They are especially going to buy Fred in Bed when Fred has to use more blankets than last year They have not forgotten last winter, bet on it. They have also not forgotten the wrong calls made on the seasonal forecasts. Don’t try to sell them an El Nino before it happens.
The attention span of Fred the Citizen won’t give you the hour-long explanation necessary to explain adiabatic. The weather report is short, and for good reason. That’s all that really matter to them, plus a couple of words about next week and the next season when appropriate.
The “hot spot” is created in the models by assuming a strongly positive feedback over the equator due to a warming sea. This is clearly wrong, observation demonstrates that, and that is why the models predict something that is not observed.
If they were to model the climate with a neutral or negative cloud / watervapour feedback as occurs in reality, the models would then correctly predict what is observed with radiosondes / satellites. But then the silly claims of 4-7 degrees would drop to 0.1 – 0.3 degrees, which would generally be beneficial (Idso calculates a co2 sensitivity FROM OBSERVATION rather than a model of 0.4 for a doubling of pre-industrial, hence 0.1 degrees of warming to come).
The “blanket” is there, the question is how thick is the blanket and how warm will it make fred, is the blanket to thin its hard to observe? Observation tells us that the blanket is thin as does little to warm him, there is no thick section of blanket over his torso making him snug and toasty and no “hotspot”!
The warming in the pipeline comment is a great point, the warmth can not hide in the sea, the air would have to warm first in order to warm the sea! The heat can not just jump straight to the sea from the upper troposphere, thats rediculous, and besides the sea is not warming!
Its a great, though simplistic, explanation, but needs to clarify what the hotspot is and why the models fail in this area. It is not due to co2 directly, but the assumed positive feedbacks.
In climate models the sun also causes the same “hotspot”.
Juraj V,
Thanks for the links. This is fascinating stuff
one haevy mistake!
the body you show (fred), is a heat engine. the time you use is too short to explaine the atmosphere with the earth. lets fred die, and kalkulate again…
and now think ist over: isnt it only a faktor of time?
Glug,
Thanks for the links.
http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2F2008JCLI2287.1
This one above seems to be saying that the observed data does not agree with the models.
The last link is for the Santer et al paper I’ve already mentioned. There does seem to be a number of issues with this. McIntyre is writting a paper to discuss these issues. Should be interesting
P Czerna: sorry i meant to write “re-radiates”, and not radiates. The heat budget is the amount of solar energy received by the earth minus the amount of heat lost by the earth over a given time period.
Tarpon 12:17 “all the Global Climate Models(GCMs) and the AGW CO2 theory predicts that there should be a measurable hotspot in the upper troposphere. Observations from satellites and weather balloons have been made, and no hotspot has been found.
That about right?”
Not quite. If the observations had fit the model, that would be the end.
But the observations don’t support the model, so a search begins to find the error in the observations. The radiosonde data is found to be on the high side; and the estimated error of the observations were found to have been underestimated. With the past tropospheric temperatures revised downward and the uncertainty of the measurement increased, it now appears that the observations (although not fully supporting the model) are not sufficient to reject the model.
The same sort of sequence has taken place in the Ocean Heat Content projections and Argos buoy data. Read how NOAA saved the world’s oceans from a cooling trend: http://earthobservatory.nasa.gov/Features/OceanCooling/ , “Correcting Ocean Cooling”. The article is a bit off topic, but it shares the same confirmation bias theme as the history of the hot spot.
We have behaved so bad that CO2 has increased in such a proportion as to provoke the opposite, an ice age, we have no time at all, all nations should start buying windmills NOW ! (bribing not allowed).