Roger Tattersall (aka Tallbloke) writes on his blog of a WUWT comment. Unfortunately WUWT gets so many comments a day that I can’t read them all (thank you moderators for the help). Since he elevated Dr. Robert Brown’s comment to a post it seems only fair that I do the same.
I saw this comment on WUWT and was so impressed by it that I’m making a separate post of it here. Dr Brown (who is a physicist at Duke University) quotes another commenter and then gives us all an erudite lesson. If Nikolov and Zeller feel they need to take any of the complaints on WUWT about the way they handle heat distribution from day to night side Earth seriously, they probably need to study this post carefully. this is also highly relevant to the reasons why Hans Jelbring used a simplified model for his paper, please see the new PREFACE added to his post for further elucidation.
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I can’t speak for your program, but I will stand by mine for correctly computing the ‘mean effective radiative temperature’ of a massless gray body as a perfect radiator. Remember, there is no real temperature in such of an example for there is no mass. It takes mass to even define temperature. (but most climate scientist have no problem with it and therefore they are all wrong, sorry)
I’d like to chime in and support this statement, without necessarily endorsing the results of the computation (since I’d have to look at code and results directly to do that:-). Let’s just think about scaling for a moment. There are several equations involved here:
is the total power radiated from a sphere of radius R at uniform temperature T. \sigma is the Stefan-Boltzmann constant and can be ignored for the moment in a scaling discussion. \epsilon describes the emissivity of the body and is a constant of order unity (unity for a black body, less for a “grey” body, more generally still a function of wavelength and not a constant at all). Again, for scaling we will ignore \epsilon.
Now let’s assume that the temperature is not uniform. To make life simple, we will model a non-uniform temperature as a sphere with a uniform “hot side” at temperature T + dT and a “cold side” at uniform temperature T – dT. Half of the sphere will be hot, half cold. The spatial mean temperature, note well, is still T. Then:
P’ = (4 \pi R^2) epsilon sigma ( 0.5*(T + dT)^4 + 0.5(T – dT)^4)
is the power radiated away now. We only care how this scales, so we: a) Do a binomial expansion of P’ to second order (the first order terms in dT cancel); and b) form the ratio P’/P to get:
P’/P = 1 + 6 (dT/T)^2
This lets us make one observation and perform an estimate. The observation is that P’ is strictly larger than P — a non-uniform distribution of temperature on the sphere radiates energy away strictly faster than it is radiated away by a uniform sphere of the same radius with the same mean temperature. This is perfectly understandable — the fourth power of the hot side goes up much faster than the fourth power of the cold side goes down, never even mind that the cold side temperature is bounded from below at T_c = 0.
The estimate: dT/T \approx 0.03 for the Earth. This isn’t too important — it is an order of magnitude estimate, with T \approx 300K and dT \approx 10K. (0.03^2 = 0.0009 \approx 0.001 so that 6(0.03)^2 \approx 0.006. Of course, if you use latitude instead of day/night side stratification for dT, it is much larger. Really, one should use both and integrate the real temperature distribution (snapshot) — or work even harder — but we’re just trying to get a feel for how things vary here, not produce a credible quantitative computation.
For the Earth to be in equilibrium, S/4 must equal P’ — as much heat as is incident must be radiated away. I’m not concerned with the model, only with the magnitude of the scaling ratio — 1375 * 0.006 = 8.25 W/m^2, divided by four suggests that the fact that the temperature of the earth is not uniform increases the rate at which heat is lost (overall) by roughly 2 W/m^2. This is not a negligible amount in this game. It is even less negligible when one considers the difference not between mean daytime and mean nighttime temperatures but between equatorial and polar latitudes! There dT is more like 0.2, and the effect is far more pronounced!
The point is that as temperatures increase, the rate at which the Earth loses heat goes strictly up, all things being equal. Hot bodies lose heat (to radiation) much faster than cold bodies due to Stefan-Boltzmann’s T^4 straight up; then anything that increases the inhomogeneity of the temperature distribution around the (increased) mean tends to increase it further still. Note well that the former scales like:
P’/P = 1 + 4 dT/T + …
straight up! (This assumes T’ = T + dT, with dT << T the warming.) At the high end of the IPCC doom scale, a temperature increase of 5.6C is 5.6/280 \approx 0.02. That increases the rate of Stefan-Boltzmann radiative power loss by a factor of 0.08 or nearly 10%. I would argue that this is absurd — there is basically no way in hell doubling CO_2 (to a concentration that is still < 0.1%) is going to alter the radiative energy balance of the Earth by 10%.
The beauty of considering P’/P in all of these discussions is that it loses all of the annoying (and often unknown!) factors such as \epsilon. All that they require is that \epsilon itself not vary in first order, faster than the relevant term in the scaling relation. They also give one a number of “sanity checks”. The sanity checks suggest that one simply cannot assume that the Earth is a ball at some uniform temperature without making important errors, They also suggest that changes of more than 1-2C around some geological-time mean temperature are nearly absurdly unlikely, given the fundamental T^4 in the Stefan-Boltzmann equation. Basically, given T = 288, every 1K increase in T corresponds to a 1.4% increase in total radiated power. If one wants a “smoking gun” to explain global temperature variation, it needs to be smoking at a level where net power is modulated at the same scale as the temperature in degrees Kelvin.
Are there candidates for this sort of a gun? Sure. Albedo, for one. 1% changes in (absolute) albedo can modulate temperature by roughly 1K. An even better one is modulation of temperature distribution. If we learn anything from the decadal oscillations, it is that altering the way temperature is distributed on the surface of the planet has a profound and sometimes immediate effect on the net heating or cooling. This is especially true at the top of the troposphere. Alteration of greenhouse gas concentrations — especially water — have the right order of magnitude. Oceanic trapping and release and redistribution of heat is important — Europe isn’t cold not just because of CO_2 but because the Gulf Stream transports equatorial heat to warm it up! Interrupt the “global conveyor belt” and watch Europe freeze (and then North Asia freeze, and then North America freeze, and then…).
But best of all is a complex, nonlinear mix of all of the above! Albedo, global circulation (convection), Oceanic transport of heat, atmospheric water content, all change the way temperature is distributed (and hence lost to radiation) and all contribute, I’m quite certain, in nontrivial ways to the average global temperature. When heat is concentrated in the tropics, T_h is higher (and T_c is lower) compared to T and the world cools faster. When heat is distributed (convected) to the poles, T_h is closer to T_c and the world cools overall more slowly, closer to a baseline blackbody. When daytime temperatures are much higher than nighttime tempratures, the world cools relatively quickly; when they are more the same it is closer to baseline black/grey body. When dayside albedo is high less power is absorbed in the first place, and net cooling occurs; when nightside albedo is high there is less night cooling, less temperature differential, and so on.
The point is that this is a complex problem, not a simple one. When anyone claims that it is simple, they are probably trying to sell you something. It isn’t a simple physics problem, and it is nearly certain that we don’t yet know how all of the physics is laid out. The really annoying thing about the entire climate debate is the presumption by everyone that the science is settled. It is not. It is not even close to being settled. We will still be learning important things about the climate a decade from now. Until all of the physics is known, and there are no more watt/m^2 scale surprises, we won’t be able to build an accurate model, and until we can build an accurate model on a geological time scale, we won’t be able to answer the one simple question that must be answered before we can even estimate AGW:
What is the temperature that it would be outside right now, if CO_2 were still at its pre-industrial level?
I don’t think we can begin to answer this question based on what we know right now. We can’t explain why the MWP happened (without CO_2 modulation). We can’t explain why the LIA happened (without CO_2 modulation). We can’t explain all of the other significant climate changes all the way back to the Holocene Optimum (much warmer than today) or the Younger Dryas (much colder than today) even in just the Holocene. We can’t explain why there are ice ages 90,000 years out of every 100,000, why it was much warmer 15 million years ago, why geological time hot and cold periods come along and last for millions to hundreds of millions of years. We don’t know when the Holocene will end, or why it will end when it ends, or how long it will take to go from warm to cold conditions. We are pretty sure the Sun has a lot to do with all of this but we don’t know how, or whether or not it involves more than just the Sun. We cannot predict solar state decades in advance, let alone centuries, and don’t do that well predicting it on a timescale of merely years in advance. We cannot predict when or how strong the decadal oscillations will occur. We don’t know when continental drift will alter e.g. oceanic or atmospheric circulation patterns “enough” for new modes to emerge (modes which could lead to abrupt and violent changes in climate all over the world).
Finally, we don’t know how to build a faithful global climate model, in part because we need answers to many of these questions before we can do so! Until we can, we’re just building nonlinear function fitters that do OK at interpolation, and are lousy at extrapolation.
rgb
@richard G
Also, even IF (roflmao) CO2 heats the atmosphere, this would increase convective activity.
Hot air rises,…… R.Gates must be on cloud 9 🙂
R.Gates
“Climate models do not predict natural variability, as that is not their intent, nor is it even possible…”
So if variability of the climate is totally (or even close to totally) natural, then the climate models are TOTALLY USELESS..
THANK YOU R’GATES… YOU FINALLY UNDERSTAND !!!! YIPEEEEEEEE !!!
The post says:
Its all too complicated. We can’t possibly understand it.
R Gates says:
We can model the essential details well enough for it to be useful.
R Gates is right.
LazyTeenager says:
January 6, 2012 at 7:27 pm
The radiators are not aimed at the floor. So tilt them over a bit. Ensure the carpet is a dark colour, ensure the radiators are a dark colour, raise the temperature of the radiators.
I’ve done that now and they are still not radiating, or if they are the radiation is minute compared to the convection. Do you think it I double the CO2 in my rooms they will start radiating. I can’t increase their temperature as the boiler is working flat out?
R. Gates says:
January 6, 2012 at 6:15 pm
Climate models are not meant to prediict natural variabilty, but they can predict what the underlying warming rates will be when natural variability forcing is removed
No they can’t, because the programmers have little clue as to how much natural variability contributed to the late C20th warming during. So the fudging of aerosol and volcanic variables for example will render any model output useless. The other main problem as Nikolov and Zeller and Jelbring point out, is that the programmers fondly imagine that all of the greenhouse effect is down to greenhouse gases and their radiative effect. This is incorrect, it’s mostly due to the compression of the lower atmosphere by gravity. Ira Glickstein has made a fundamental error in assuming the gradient caused will dissipate to surroundings. All the surroundings at a given altitude are subject to the same gravitational compression and heating, so there is nowhere for the effect to dissipate to.
LazyTeenager says:
January 6, 2012 at 6:48 pm
thepompousgit says
Sorry LT, you are wrong. A photon has a rest mass of zero. But photons aren’t at rest; they fly hither and thither at the speed of light. If photons were massless, they would be unable to exert pressure.
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Your right of course, though we typically speak of photons as having momentum and energy rather than mass.
Momentum is a product of mass and velocity. Or it was when I learned classical mechanics. If photons are exempt from classical mechanics I’d like an explicit explanation please.
Good post.
The earth is not a sphere with a uniform surface or even a surface of the same material. Every day one hemisphere has completely different heat qualities to the other due to its rotation and the fact that one half, approximately, is water the other land. To state that heat loss/gain at any time can be modeled is a claim too far. To also make assumptions about pre-industrial atmospheric CO2 content to be lower than today’s is also wrong. They may have been higher, according to measurements in the 1890’s they certainly were.
I will stick with Nikolov and Zeller at the moment.
R. Gates says:
January 6, 2012 at 5:54 pm
Bill Illis said:
Regarding the temperature of the Earth without an atmosphere:
“The surface temperature would be -18C in the daytime, approaching -110C within a few seconds of the Sun setting.
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Not quite. The daytime temperature near the equator would be more like 130C and the nighttime temperature would fall to -110C within several hours after sunset (assuming no ocean). Cooling of the moon’s suface during lunar eclpises confirms this general rate. The rocks and soil would continue to release stored LW for several hours after the sun went down.
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The moon is in sunshine for 327 hours. This allows a tiny, tiny fraction of the solar radiation to accumulate over time in the rocks. Over 327 hours (1 million seconds), the accumulation can add up to a large number. The Earth is in sunshine for only 12.0 hours so its rocks/surface would not warm up so much in the day. So, maybe -10C or something rather than -18C.
Venus, by contrast, rotates very slowly (and backwards), so is in sunshine for 243 days at a time. Now think of how a small, tiny accumulation rate in energy (0.0007 joules/second on Earth) can translate into temperature increases. If the Earth rotated like Venus, the temperatures on the day-side would increase to 1000C (yes thats right) !!!!! Now throw in Venus’ thick atmosphere and strong winds spreading the energy around to the darkside and we can explain Venus temperatures to the T.
Regarding my comments above at January 7, 2012 at 3:55 am, about Venus and being in the Sun, I redid my calculations and the numbers would be more like 470C. By contrast, Venus’ surface temperatures are 460C.
Camburn says:
January 6, 2012 at 11:53 pm
Also R. Gates:
The drop of water is never going to get to the edge of the glass as the film function of the water droplet will evaporate before it can make it.
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Of course you are making assumptions here about the size of the glass plate, how big the water drop was, relative humidity, etc.
The essential point was that there can be natural and unpredictable variability within an overall trend to allow a model to not be 100% right, but still be useful in looking at the overall trend.
Tallbloke says: “If photons are exempt from classical mechanics I’d like an explicit explanation please.”
You need to leave the 1800’s behind and read up on relativity. Pretty much by definition, relativity was the end of “classical physics” and showed that classical physics was incorrect in many fundamental ways, including how momentum was defined.
R. Gates says:
January 7, 2012 at 5:41 am
When I was a kid I used to assemble model cars, airplanes, etc. I once made a dimensionally correct model of an uncle’s house. Know what? I coludn’t drive, fly, or live in any of them.
Tim Folkerts says:
January 7, 2012 at 6:52 am
Tallbloke says: “If photons are exempt from classical mechanics I’d like an explicit explanation please.”
You need to leave the 1800′s behind and read up on relativity. Pretty much by definition, relativity was the end of “classical physics” and showed that classical physics was incorrect in many fundamental ways, including how momentum was defined.
How does Einstein define the momenta of photons Tim?
The waving of hands around general statements doen’t cut it with me I’m afraid. In engineering, you have to have definitions. Please don’t think I’m trying to put you on the spot. You can always just say:
“I don’t know”
jjthoms says:
January 6, 2012 at 8:11 pm
An error of 1.8% – i.e. an error bot not gross
An error of 1.8% in surface radiation exceeds the total amount of radiation attributed to CO2.
It explains why the climate models have done such a poor job of prediction outside of a very narrow span of time from 1975-1995, when natural variability happened to coincide with the magnitude of the error.
Concerning models in the IPCC reports, I think this says it all:
http://tomnelson.blogspot.com/2012/01/don-miss-this-devastating-criticism-of.html
R Gates Jan 6, 2012 9:28 AM
“Models don’t have to be 100% accurate to be useful. ”
What % accurate are the computer models that you use?
No thought experiments please….just an answer.
tallbloke says:
January 7, 2012 at 7:11 am
How does Einstein define the momenta of photons Tim?
Einstein’s insight was that the energy of light was not a product of its intensity, rather its wavelength. Something that is completely overlooked by climate science in its discussion of W/m2, which ignores wavelength when computing climatic effects.
For example the climatic effects of Solar UV variability on Ozone production have been completely overlooked, in favor of securing patent advantage. As a result of the CFC disinformation campaign even to this day large numbers of people believe the Ozone hole is a result of human activity such as hairspray and air-conditioners.
Yet polar vortexes (holes) are routinely observed on planets and moons that have no humans. It is the cold air descending though the vortex that scrubs the poles of ozone and transfers if to the lower latitudes, greatly affecting the earth’s climate. The effect is most pronounced at the south pole in winter, where temperature extremes are the greatest.
Regulation and DuPont
In 1978 the United States banned the use of CFCs such as Freon in aerosol cans, the beginning of a long series of regulatory actions against their use. The critical DuPont manufacturing patent for Freon (“Process for Fluorinating Halohydrocarbons”, U.S. Patent #3258500) was set to expire in 1979.
http://en.wikipedia.org/wiki/Chlorofluorocarbon
ferd berple says: January 7, 2012 at 7:19 am
An error of 1.8% in surface radiation exceeds the total amount of radiation attributed to CO2
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Good grief. I was just pointing out that your sums were wrong (they give 100% error at +-15C.
I think 30K diff night to day is extreme – so the actual error is much less!!!!!!
Tallbloke asks “How does Einstein define the momenta of photons Tim?”
The “blog answer” to your question is that
E^2 = p^2 c^2 + m^2 c^4
so for a particle with no mass, p = E/c = hf/c.
(For particles with mass at rest, this equation instead becomes the famous “E=mc^2”)
Beyond that, I’m afraid people must google “relativistic momentum” and/or dig a lot deeper to start to understand relativity.
R. Gates says:
January 6, 2012 at 6:15 pm
Climate models are not meant to prediict natural variabilty, but they can predict what the underlying warming rates will be when natural variability forcing is removed, so to answer your question– none have “predicted” these specifics as none are meant to.
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Gates, if computer games can not predict natural variability, then they have no knowledge of it….
..if that’s the case, then computer games can not differentiate what is natural variability and CO2 .
We have spent this much time and money on computer games that can do what any child can do…and that’s just extend a trend line
….if this trend continues
As a physicist myself, I love the approach of looking at the basic principles and considering the major factors. And I agree with most of what was said by Dr Brown.
I have one subtle but important reservation about the analysis that is summed up in the innocuous statement “Basically, given T = 288, …. “
The analysis has been all about radiation balance. The one most fundamental equation in the post is the first he presents:
With earth’s current albedo, it is easy to show that a uniform temperature of ~ 255 K would be required to radiate sufficient power to maintain radiative balance. This defines the “effective Temperature”, T_e at the “surface”. The earth receives and average of about 1370 W/m^2 / 4 = 342 W/m^2 from the sun and reflects about 30%, leaving about 240 W/m^2 when averaged over the whole world. This leads to an effective temperature, T_e = 255 K.
How can earth’s surface temperature change from this 255 K value?
1) Redistribution of energy. As pointed out by Dr Brown, a more realistic earth with temperature variations would be a few degrees cooler. The “effective temperature” would still be T_e = 255 K because the overall radiation balance has not changed , but the “average temperature”, T_avg, would be lower. Changes in atmospheric or ocean circulation could change T_avg a few degrees, so I agree with Dr Brown here.
2) Albedo. A different method that was mentioned would be to change the earth’s albedo. This would be fundamentally different from changing the circulation, since it would change the effective temperature above or below T_e = 255 by changing the amount of energy absorbed by the planet. This also could easily change T_e by a few degrees and hence change T_avg by a few degrees, so for a second time I agree with Dr Brown .
3) GHGs. A third method is to add greenhouse gases (GHGs) = gas molecules that can emit IR radiation. This is fundamentally different from either of the previous two methods. In fact, the author has already admitted the power of GHGs to change the temperature by large amounts through that innocuous statement “Basically, given T = 288, …. “.
GHGs do not change the albedo, and hence do not change the effective temperature from 255 K. What they DO change is the “surface” of the earth, at least as it related to radiation. For every square meter on the earth, some of the outgoing radiation (as seen from space) is coming from CO2, and this radiation comes from high up in the cold atmosphere (see for example http://wattsupwiththat.com/2011/03/10/visualizing-the-greenhouse-effect-emission-spectra/ for some typical data). To compensate, every square meter on the earth must have some parts that are well above 255 K. In other words, the ground level must be well above 255 K.
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Dr Brown said “I would argue that this is absurd — there is basically no way in hell doubling CO_2 (to a concentration that is still < 0.1%) is going to alter the radiative energy balance of the Earth by 10%. “
I would go even further and say there is basically no way in hell doubling CO_2 would change the radiative energy balance (of the earth as a whole) by even 1% (because is does not change the albedo)! But what it can do is change where that energy comes from, forcing some of the radiation to come from very cold places (~ 220 K upper atmosphere) and consequently some of it to come from warm places (~ 288 K surface) to compensate.
R. Gates says:
January 7, 2012 at 5:41 am
The essential point was that there can be natural and unpredictable variability within an overall trend to allow a model to not be 100% right, but still be useful in looking at the overall trend.
You are rationalizing. What the models show is that there is HUGE natural variability. Each run of the models generates a different result which points to this variability. In fact, it screams natural variability. Why? Because the earth itself is a full-sized model. And if you ran the identical earth two times, each time it would have a different climate.
However, Climate Science ignores this. What they do is average the models to create an ensemble which eliminates the natural variability. They then present this average as a prediction of what will actually happen.
It is garbage science of the worst kind. What the models actually show is that there is a very wide range of climate possibilities, regardless of human activity. As they try and increase the resolution of the models, this variability increases.
What the models show is that climate change is the natural order of the world. That the “predictability” of climate models is a result of averaging inside the models to allow for computational problems in handling large amounts of data (the average temperature of the earth problem).
What the models show is that as you increase computer horsepower to increase model resolution, the models show increasing natural variability not less. The models are screaming natural variability. Climate Science is screaming “humans are the cause”. So, the models are averaged to eliminate the natural variability in the models.
If you want to claim that CO2 did not play a part in all these temperature changes, then you need to read these scientific papers and email them your reasons why they are wrong.
“GEOCARB III: A REVISED MODEL OF ATMOSPHERIC CO2 OVER PHANEROZOIC TIME” ROBERT A. BERNER (http://earth.geology.yale.edu/~ajs/2001/Feb/qn020100182.pdf).
“CO2 as a primary driver of Phanerozoic climate” — D. Royer et al, GSA Today, March 2004 (http://droyer.web.wesleyan.edu/GSA_Today.pdf)
“CO2 forced climate thresholds during the phanerozoic”, Dana L. Royer 2005 (http://droyer.web.wesleyan.edu/PhanCO2(GCA).pdf)
“Atmospheric CO2: Principal Control Knob Governing Earth’s Temperature”, Andrew A. Lacis, Gavin A. Schmidt, David Rind and Reto A. Ruedy, 2010 (http://www.sciencemag.org/content/330/6002/356.abstract)
jjthom says:
January 7, 2012 at 8:01 am
I think 30K diff night to day is extreme – so the actual error is much less!!!!!!
The difference between the equator and the poles exceeds 30K almost continually, which makes the error much greater. Add to this, seasonal variations which exceed 30K in many locations outside the tropics.
The fact remains. Climate Science has made a fundamental error in averaging temperatures to compute an energy budget. A correct calculation requires that radiation be computed before temperatures are averaged. The magnitude of this error exceeds that warming calculated for CO2.
Well, heck, I certainly never expected this response to what was just supposed to point out that any models that assume that Stefan-Boltzmann based reasoning with a presumed constant/average temperature would make a systematic error biased towards less cooling than really occurs, all other things being equal.
Let me just add that
a) this wasn’t intended to be a model. Sure, if you take this and dress it up and turn it into a really big computer program (one that is indeed suitable for running on a good old beowulf:-) you could do a calculation with it. You could then make a lot of assumptions — assumptions about the insolation, the albedo, the exact feedback produced by water, the upwelling, the effect of the ocean and it’s thermal cycle with it’s many time scales, and the precise layout and shape of the continents. If your model didn’t have all of that in it, and correct, then it is pretty unlikely that a hydrodynamic computation — presuming one could do one at all, even with a beowulf — would (for example) spontaneously discover the ENSO, PDO, NAO, AO, etc. with all of the correct periods and with all of the correct feedbacks and couplings to (still unmodeled) solar state.
Is this a problem? In a chaotic system it is. Visit this site:
http://en.wikipedia.org/wiki/Chaos_theory
and take a peak at the two figures on Lorentz Attractors and the bifurcation diagram just below it. Then visit the shorter article here:
http://en.wikipedia.org/wiki/Self-organized_criticality
I would assert that it is perfectly obvious that the Earth’s climate system — not its weather, its climate — is a very large SOC system, one with many, many attractors, some of them nearly always critical on at some scale. The many attractors means that it is at least multistable, quite capable of flipping from one predominant mode of oscillation to another. The “self-organized critical” bit means that there are negative feedbacks galore (and some positive ones) and the time evolution of the system can actually push the attractors themselves around.
Multistability is clearly supported by the climate record. It isn’t a picture of simple central limit theorem oscillation, simple negative feedback oscillation around a single fixed mean. It is a picture of flipping to a locally quasistable mean temperature, hanging there for decades to centuries, flipping (fairly rapidly) over to another quasistable mean temperature, staying for a while, flipping again. Even periods of relatively long warming or cooling tend to work by quick jumps followed by stabilization and fluctuation, followed by a quick jump. Bob Tisdale has been hammering this point in his graphs, and of course he is dead right.
The jumps in his graphs are usually well correlated with chaotic events events associated with the named oscillations (which are all, incidentally, named attractors in a generalized phase space), which is why there is an oscillation in the first place). All of this emphasis on “detecting the warming signal” by removing the effects of the oscillations is like removing the cause of the warming signal in order to detect it.
The emphasis on global mean temperature also hides another problem — the global mean isn’t really what matters. What matters is the distribution of global heat. The earth itself can be cooling while the arctic is warming. The tropics could get hotter and the poles could get colder if the earth itself overall was warming. It’s a complex system, self-organizing itself to lose heat by stabilizing a set of coupled oscillations that themselves can move around and appear and disappear, with profound local and global effects on the climate.
b) When I asked the rhetorical question, could we tell what the temperature is supposed to be outside right now I did not mean in the sense of 48.3F at my house. Don’t be silly. What I meant was could you e.g. predict the thirteen month smoothed global mean temperature? Well, no, the GCMs can’t do that with any skill. Can you predict the 11 year smoothed mean temperature? No, GCMs can’t do that with any skill either, certainly not on millennial time scales. Can they explain the LIA, the MWP, or all of the other named periods of heating and cooling on geological time scales? No. Can they predict El Nino — location, strength, period? No. Can they predict solar state and accurately incorporate solar state as an influence in their time evolution. No again. Can they — did they — predict that the stratosphere would have dried out significantly over the last decade so that the greenhouse feedback from the stratosphere would be significantly reduced? I believe that the answer is no again — at least the NASA article that presents the results presents them as a surprise. Do they account for the fact that the 20th century was a Grand Solar Maximum, the most intense century of solar activity since 9000 BCE? I don’t believe that they do, since they assert that solar state is nearly irrelevant to global climate all evidence to the contrary notwithstanding.
So let me ask the question in a way that is perhaps easier to understand. Do the GCMs have any skill whatsoever in predicting the quantitative time evolution of any of the major structures (climate oscillations) in the non-linear system that self-organizes to lose heat at differential rates under differential forcing, so that they can actually predict — hindcast or forecast, ideally both — the last 2000 years of suitably coarse grain averaged global temperatures?
I don’t think that they can. I don’t think they can at all. Historically, alteration — or even just alternation — of the major climate cycles has had a profound effect on global temperatures, suggesting that there are heat gain and loss mechanisms capable of producing delta-Ts consistent with current observations with periods that range from decades to centuries. We don’t have observational data of any quality, even by proxy, sufficiently reliable to even know what they all are, or may be. If the Gulf Stream ticks a few degrees South every 400 years or so for a period of 100 years, it could drop the Arctic into the freeze box any decade now.
My objection, you see, is to call all of this “settled science”. If and when people are honest with their error bars and uncertainties, “catastrophe” goes from the certainty presented in the public debate to a long shot that isn’t being borne out by the observational data, which stubbornly sticks to levels that, extrapolated, do not lead to any sort of catastrophe. The catastrophe arises from one thing, and one thing alone: A presumed (unproven! unmeasured!), strong, positive climate feedback.
In a self-organized critical chaotic system, such things are always to be feared. As I said, small changes can alter the patterns, the attractors themselves, merging or splitting poincare cycles, causing the system to move from oscillation around one to predominant oscillation around a different one. “Catastrophe” in the sense of mathematical catastrophe theory is always a possibility, and in the climate record happens (remember, these aren’t “human” catastrophes, they are sudden switches between chaotic regimes) catastrophes are the order of business — they happen all the time. They are clearly visible in Tisdale’s data and analysis — things like SST don’t go smoothly up or smoothly down like a differential linearized model would predict, they jump up a little (often pushed by El Nino) and then stabilize or even slowly drop, jump down a little and stabilize. Many, many attractors, and big oscillations carelessly swatting global circulation and oceanic circulation around between them.
Nevertheless, there is more than enough evidence already to reject the extreme values of climate sensitivity that would lead to catastrophic warming in the linearized/smoothed models. The climate scientists themselves recognize this, and say it bluntly in Climategate2. The fact that the global temperature hasn’t cooperated by going up over the last decade plus is a disaster, not for weakly forced anthropogenic global warming (that nearly everybody acknowledges is occurring, I certainly do) but for catastrophic AGW. Sure, something really unexpected could happen, oceanic methane could go bloop, Yellowstone could become active — but the all things equal solutions no longer support catastrophe of the human sort. Seriously, dudes, like stop worrying!
To this one has to add — if one considers the non-linear, self-organized critical chaotic time evolution with all of the correct (self-consistent) contributions from all of the important timescales out to perhaps 1000 years (complete oceanic turnover) and the unknown but compelling evidence that Mr. Sun may not just be a wild card, it may be in the driver’s seat altogether, it is almost as likely that our next climate catastrophe will be catastrophic cooling as it is catastrophic warming. The trend of the Holocene for many thousands of years — very nearly since that last Grand Maximum — has been generally downward, and somewhere out there in climate phase space the set of attractors collectively known as “the next Ice Age” are self-organizing and strengthening. So far, there is a sufficient barrier between warm-state attractors and cold-state attractors — the major climate bifurcation clearly visible in the record — but that barrier is lowering, in response to variable and parameters we are in nearly complete ignorance of.
So from my point of view, what is lacking in the global political discussion of CAGW is simple honesty. This is a hard problem. Calling it “settled science” to advance a political agenda does a disservice to humanity. The actual papers that study climate science often (but not always) do present the uncertainties of their results honestly, but those uncertainties never seem to make it into the AR reports of the IPCC, perhaps because the scientists are currently being told what to put in them before they even get together to go over the science.
Nature, like Honey Badger, just doesn’t care (google up “Honey Badger doesn’t care” and watch the youtube video:-). Neither does the progress of science and technology. Nothing we do with “Carbon Futures” now will have anything like the impact on CO_2 required to prevent catastrophe if egregiously positive feedback is correct. Nothing we do with Carbon Futures now will alter the fact that over the next three decades, economic scarcity will all by itself drive 1/2 to 2/3 of the world’s energy production into non-carbon based sources, or into recycled carbon based sources, which will have the kind of impact required to perhaps avoid catastrophe.
If climate feedback is neutral to negative — as it appears to be given the actual evidence so far — then there is no need to panic. If it is weakly positive, there is no need to panic or take much action beyond supporting the continued development of carbon alternatives — we have plenty of time before catastrophe becomes likely, and plenty of time to take urgent action if it is ever required. Only in the egregious case do we need to be worried, and as I said, the entire climate record stands as evidence that we do not have egregiously positive feedback in the climate system. Even where there are sudden jumps, they are not to be understood from the linearized view of positive feedbackc, but rather from the point of view of appearing and disappearing turbulent rolls, variations in the self-organized chaotic major circulatory oscillations that ultimately and empirically heat and cool the Earth in relatively rapid bursts every few decades, in response to a changing sun and solar system more than any other single thing.
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Congratulations Antnee!
R.Gates
“Climate models do not predict natural variability, as that is not their intent, nor is it even possible…”
The main reason I chose The Younger Dryas was to put the current alarmism into some perspective. TYD represents roughly 150 times the temperature change per decade that we were experiencing before 1997.
There were events that led to TYD, as was there events and conditions that led to the LIA, MWP and every other natural change. If it were possible to know and understand ALL of the inputs then they would not be Black Swans. While those skills are long way from realization, you ignore natural change at your own peril, as 98% of all the species that ever existed on this planet will attest.
I do agree with you that climate models do not predict natural variability and it was never their intent. The emails make that very clear. Looking back to the mid 90’s and the loss of AGW signal hence, I would say the models don’t even predict Catastrophic Anthropogenic Global Warming Climate Disrupting Species Annihilating Ocean Level Rising and Acidification (or whatever the nom du jour is).