by Judith Curry
The thread on the recent Loehle and Scafetta paper (here and WUWT) have spawned the term “cyclomania” in the context of searches for natural cycles that can explain 20th century climate change and potentially predict climate change in the 21st century.
Cycles Research Institute
For those of you who are cyclomaniacs, you can indulge your mania at the Cycles Research Institute blog. The mission of the CRI:
“Our mission is to discover, understand, and explain the true nature and origin of cycles, thereby solving the mystery of recurrent rhythmic phenomena, as has been observed in both the natural and the social sciences, and while so doing, to instruct others, and to apply this new knowledge for the greater good of all life.”
The principals of the CRI include a physics professor, a professor of finance, market analysts, and Climate Etc. denizen Rog Tallbloke.
Some analyses of climate cycles
On timescales of decades to centuries, there have been several analyses of global climate cycles (on decadal and multidecadal time scales):
Loehle and Scafetta argue that previously observed cycles in solar motion and activity of 60 and 20 years, combined with an anthropogenic trend, can be used to model Earth temperature variations.
Actually, two and a half years ago I replicated the Global Surface Temperature record from about 1900 to present using only NINO3.4 SST anomalies, volcanic aerosol and sunspot data. My results also include the year-to-year wiggles. Do yours?
http://i43.tinypic.com/2hztthw.jpg
The graph is from the following post:
http://bobtisdale.wordpress.com/2009/01/25/reproducing-global-temperature-anomalies-with-natural-forcings/
Here is another near perfect wiggle match (with accelerated response since 1995)
http://www.vukcevic.talktalk.net/Contents.htm
to coincide with sudden departure from natural event in 1995
http://www.vukcevic.talktalk.net/WPd.htm
but what does it mean?
http://www.vukcevic.talktalk.net/NAOn.htm
Appinsys has an extensive post on 60 year cycles.
I also just spotted this new analysis by Clive Best.
I’m sure there are other similar analyses, these are ones that I have recently encountered. There are relatively few papers on this topic that have been published for global climate, but numerous papers have been published for regional climate. I would appreciate the citation of any articles that you are aware of on regional or global climate cycles on century time time scales.
Oscillations vs cycles
The favored period for cycles in these analyses seems to be 60, 20, and 9 years. A range of different mechanisms have been proposed (both forced and unforced).
In a chaotic system, one wouldn’t expect cycles but rather oscillations. Even regular external forcing is likely to result in an irregular and possibly lagged response. While variations in the sun, planetary orbits and magnetic fields may appear cyclic on some timescales, they are not cyclic on much longer timescales. For example, the Wikipedia has this to say on orbital variations:
Though the planets have been stable historically, and will be in the short term, their weak gravitational effects on one another can add up in unpredictable ways. For this reason (among others) the Solar System is chaotic, and even the most precise long-term models for the orbital motion of the Solar System are not valid over more than a few tens of millions of years.
Sunspots are cyclic, except for when they disappear for long periods such as during the Maunder minimum.
Oscillations such as the AMO and PDO are not cycles but irregular oscillations, with irregular periods. Assuming that the AMO and PDO are manifestations of natural internal variability of a chaotic system, the existence of these particular modes may come and go at any time.
In a complex chaotic system, there is no reason to expect that the forcings and response are easily separable from the decadal modes of natural internal variability. I think the approach of Tsonis in terms of diagnosing climate shifts in a chaotic system (synchronized spatiotemporal chaos) is generally the correct way to go in sorting this out.
The IPCC’s 20th century attribution problem
The IPCC’s attribution argument assumes that 20th century climate variability and change can be explained solely by external forcing (volcanoes, aerosol, greenhouse gases, solar). While the ambiguous word “most” in the IPCC’s attribution statement leaves room for unspecified natural internal variability and unknown forcing, their discussion of attribution makes clear their assumption of forced variations.
My judgment of the failure of the IPCC to make a convincing argument at the “very likely” confidence level was discussed in numerous previous posts, notably this post. Further, the only CMIP5 simulations that I’ve seen to date (NCAR) show results that don’t do a very good job of capturing either the magnitude of the trend or the decadal scale wiggles. So the possible explanations are:
- natural internal variability
- inadequacies in the forcing data for known agents
- unknown forcing agents
- model inadequacies
Sorry for repeating myself:
Cyclomania is better than epicyclomania (CO2GW)!
…or maybe “better than carbomania”?
Carbomania necessarily leeds to epicyclomania just like the geocentric system leeds to epicycles.
“… In some fields the science is indeed ‘settled.’ For example, plate tectonics, once highly controversial, is now so well-established that we rarely see papers on the subject at all. But the science of global climate change is still in its infancy, with many thousands of papers published every year. In a 2003 poll conducted by German environmental researchers Dennis Bray and Hans von Storch, two-thirds of more than 530 climate scientists from 27 countries surveyed did not believe that ‘the current state of scientific knowledge is developed well enough to allow for a reasonable assessment of the effects of greenhouse gases.’ About half of those polled stated that the science of climate change was not sufficiently settled to pass the issue over to policymakers at all.
“Solar scientists predict that, by 2020, the sun will be starting into its weakest Schwabe solar cycle of the past two centuries, likely leading to unusually cool conditions on Earth. Beginning to plan for adaptation to such a cool period, one which may continue well beyond one 11-year cycle, as did the Little Ice Age, should be a priority for governments. It is global cooling, not warming, that is the major climate threat to the world, especially Canada. As a country at the northern limit to agriculture in the world, it would take very little cooling to destroy much of our food crops, while a warming would only require that we adopt farming techniques practiced to the south of us.
“Meantime, we need to continue research into this, the most complex field of science ever tackled, and immediately halt wasted expenditures on the King Canute-like task of ‘stopping climate change.'”
–R. Timothy Patterson (professor and director of the Ottawa-Carleton Geoscience Centre, Department of Earth Sciences, Carleton University)
“So in response to Chris Colose’s query: “Why are you hosting this Judith?” Here is my answer. We need to dig deeper to understand natural variability on decadal and multidecadal time scales…. So at Climate Etc., we will continue to discuss the attribution issue and seek to explore the unknown unknowns associated with natural climate variation on decadal to multidecadal timescales.”
Hurrah, good for you Judith.
Now how about adding the only cycles analysis of solar activity which has ever resolved the Maunder Minimum to the main post. Hmmm? :)
The post also discusses Johnny von Neumann’s wry observation of being able to make elephants wiggle their trunk given enough free variables.
http://tallbloke.wordpress.com/2011/02/21/tallbloke-and-tim-channon-a-cycles-analysis-approach-to-predicting-solar-activity/
I always find myself wondering at the “Why are you hosting this Judith?” questions. As Fred pointed out, the discussion was informative. Why the seeming dismay at its posting?
Hi, my name is steven and I am a cyclomaniac. My current addiction involves extensive attributions to the AMO.
Hi, my name is Hansen, I seem to be suffering an acute case of hyper-bolic carbon-dioxia and rising water on the knees.
Oscillations vs cycles?
What’s the difference?
Edim,
Cycles are oscillations with a regular period. There are oscillations in nature which have irregular periods, eg the glacial / interglacial oscillation. Such aperiodic oscillations are associated with chaotic systems.
Aperiodic? every 100,000 years for the last couple of million, and every 41,000 years before that. Both of these numbers relating to Earth’s orbital parameters, eccentricity of orbit, and axial inclination.
Chaos?
It would be interesting to see formal tests for cycles.
bring out your data. that means dont cite papers without data available. I treat them like Mc treated mann. no data, no reason to believe
Here’s a nice place to start reading on methods.
http://web.archive.org/web/20100104073057/http://tamino.wordpress.com/2009/12/31/cyclical-probably-not/
note how it looks like we can identify periods from random data
Steve, there not much doubt about planetary periodicities. It’s the Earth paleo proxies which cause the trouble. We’ve been looking at possible ways the x-axis may be fouled up on various time series and thinking about how we might fix that.
Plenty of FFT’s and Chirp analyses of interesting time series on the blog. Data available on request. Fill yer boots.
e.g. http://tallbloke.wordpress.com/2011/07/18/14c-as-a-proxy-but-for-what-exactly/
http://tallbloke.wordpress.com/2011/07/12/proxy-fixup-solar-10be-and-14c/
http://tallbloke.wordpress.com/2011/07/07/the-luxembourg-effect/
http://tallbloke.wordpress.com/2011/07/06/abc-on-alloying-berylium-and-carbon/
did you read tamino on FFTs.
I bet not
Actually I did, since you’d considerately given a link which obviated the requirement to give the mathturbator in chief a hit on his blog.
mosher, I’ve shown you several papers on change in sunshine over the 20th century that appear quite cyclic.
You have always (when you deign to respond) attempted to turn the conversation to TSI … which you know full well is not what I’m talking about.
IPCC has no section on change in bright sunshine as measured by sunshine recorders like Campbell-Stokes.
And when pushed you then try and claim clouds/aerosols are interchangeable with bright sunshine. They aren’t.
I don’t think you are seeker of knowledge. You just like your pet theory – CO2 … and you push it.
you’re wrong
Solar cycles (~11 years) for example are not really regular. When people imply cycles in the climate record, they mean oscillations?
Dedicated to all Cyclesians, Cyclephants, Cyclestrians and Cyclephobes:
“… Bashkirtsev and Mashnich conducted wavelet-spectra and correlation analyses of Irkutsk and world air temperatures and Wolf number data for the period 1882-2000, finding periodicities of 22 (Hale cycle) and 52 (Fritz cycle) years and reporting that ‘the temperature response of the air lags behind the sunspot cycles by approximately 3 years in Irkutsk and by 2 years over the entire globe.’
“Noting that one could thus expect the upper envelope of sunspot cycles to reproduce the global temperature trend, they created such a plot and found that such is indeed the case. As they describe their results, ‘the lowest temperatures in the early 1900s correspond to the lowest solar activity (weak cycle 14), the further temperature rise follows the increase in solar activity; the decrease in solar activity in cycle 20 is accompanied by the temperature fall [from 1950-1970], and the subsequent growth of solar activity in cycles 21 and 22 entails the temperature rise [of the last quarter century].’
“With respect to the future, Bashkirtsev and Mashnich say ‘it has become clear that the current sunspot cycle (cycle 23) is weaker than the preceding cycles (21 and 22),’ and that ‘solar activity during the subsequent cycles (24 and 25) will be, as expected, even lower,’ noting that ‘according to Chistyakov (1996, 2000), the minimum of the secular cycle of solar activity will fall on cycle 25 (2021-2026), which will result in the minimum global temperature of the surface air (according to our prediction).’
“… ‘the available data of observations support our inference about the cooling that has already started,’ noting that ‘the average annual air temperature in Irkutsk, which correlates well with the average annual global temperature of the surface air, attained in 1997 its maximum equal to +2.3°C” and then ‘began to diminish to +1.2°C in 1998, +0.7°C in 1999, and +0.4°C in 2000.'”
(Is the Global Warming Bubble About to Burst? Volume 6, Number 37 – 10 September 2003: http://www.co2science.org/articles/V6/N37/EDIT.php)
If SC25 is also weak, the cooling will be dramatic!
My understanding is SC25 is supposed to make 24 look active.
http://science.nasa.gov/science-news/science-at-nasa/2006/10may_longrange/
I disagree with that forecast. Weak cycles are long and SC24 will not be over before 2021/22.
I don’t disagree that he predicted the current cycle inaccurately. That doesn’t mean his entire work is useless. He could very well have made the proper diagnosis, that a slowing conveyer belt leads to a weaker cycle, while making a bad prognosis that this wouldn’t manifest itself until SC25.
Judith writes “Sunspots are cyclic, except for when they disappear for long periods such as during the Maunder minimum.”
This is really off topic, and a bit tongue in cheek, but on this issue I am a stickler for detail. This statement is patently untrue. See The Prolonged Sunspot Minimum 1645-1715 by E. Walter Maunder 1922 Journal of the British Astronomical Society 32: 140.
Quote “If I may repeat the simile which I used in my paper for Knowledge in 1894, “just as in a deeply inundated country, the loftiest objects will still raise their heads above the flood, and a spire here, a hill, a tower, a tree there, enable one to trace out the configuration of the submerged champaign,” so the above mentioned years seemed to be marked out as crests of a sunken sun spot-curve.”
The sunspot cycles were discernable during the Maunder Minimum according to Edward Walter Maunder.
“Sunspots are cyclic, except for when they disappear for long periods such as during the Maunder minimum.”
Judith, splitting hairs here a little but would not the change of state of the sun from “visible sun spots” to “blank sun” and back again surely be considered a “cycle”. The fact that our observed count of sun spots starts in the late 1600’s doesn’t change the fact that there will be a periodicity that has two states “spots visible” and “no sun spots”. Such a cycle is suggested by the observed evidence ie Maunder Minimum and the present SC24. It’s just that we don’t have enough evidence from the past as to what that cycle actually looks like. But it is mostly likely there.
I think ‘episodic’ and ‘oscillating’ would be beter ways to think about cliamte variability. And add to that ‘constrained randomness’. At small scales, as we see in the AGW movement as well s the first US climate debate, a great deal of information can be claimed to discernible from very marginal variations .
Oscillating is the word. Everything in nature oscillates.
Judith,
Thanks for the response. I fully agree all of the climate issues you discussed should continue to be studied (and have been, and will continue to); however, in many cases we know enough to say some useful things. For example, El Ninos don’t cause long-term secular trends in global temperature, an absurd violation of conservation of energy and inconsistent with changes in ocean heat content, the direction of the planetary energy imbalance, etc
The problem is that you and the WUWT crowd are too gullible and are ready to jump onto any new idea, or at least wave the “this is interesting!” flag, even if it is a complete misapplication of what is known about the phenomenon or devoid of any consideration of physics. The whole point is to cast doubt on the primacy of CO2, rather than think intelligently about the *new* hypothesis, and its explanatory and predictive power. Curve fitting doesn’t do that.
I also leave with this quote from Ray Pierrehumbert:
//”…No other theory based on quantified physical principles has been able to do the same. If somebody comes along and has the bright idea that, say, global warming is caused by phlogiston raining down from the Moon, that does not make everything we know about thermodynamics, infrared absorption, energy balance, and temperature suddenly go away. Rather, it is the job of the phlogiston advocate to quantify the effects of phlogiston on energy balance, and incorporate them in a consistent way beside the existing climate forcings. Virtually all of the attempts to poke holes in the anthropogenic greenhouse theory lose sight of this simple and unassailable principle.”//
Chris, the problem that I have with you and your “crowd” is that you think that you know more than you actually do, and you ignore the possibility of ignorance. Take a look at Fig 12 in the article on the NCAR CCSM CMIP5 simulations, and then come back and tell me how we understanding the attribution of 20th century climate change. Are you interested in understanding the climate, or are you interested in establishing the primacy of CO2?
The fallacies in raypierre’s reasoning as related to that statement are numerous. Rejecting the IPCC explanation does not require a better explanation to demonstrate that it is inadequate. Translating our physical understanding of the Tyndall gas effect into a high level of certainty about the response of the chaotic complex climate system to CO2 forcing requires a very complex argument (for which the IPCC relies heavily on circular reasoning). And finally, it is not either CO2 or natural variability, but rather it is a combination of both. The real scientific challenge is to understand the relative contributions. The ambigious “most” in the IPCC’s attribution statement does not inspire confidence that they understand this very well. The word “most” implies that it very likely could be 51%, but your crowd is adamant that it could not possibly be 49%.
Judith,
Ignorance is not an excuse to violate physics or make up your own pet theories and pretend it is just as good as everyone else’s. Physical science doesn’t come in nice packages labeled “perfectly understood” and “completely ignorant” which is why honest people like to study it, resolve uncertainties, and place them in a broader context. Making things up does not count. This includes saying the argument for why we think the CO2 response is what it is involves circular reasoning. You’re just making stuff up. The evidence summarized is in http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch9s9-7.html#table-9-4
As to Figure 12, formal attribution cannot be done by the mere agreement between a modeled and observed time series; in fact, as Reto Knutti argues, attribution can often be done without simulating the amplitude of climate change; as a corollary, a perfect agreement does not necessarily imply a successful attribution. If you read the paper, you will note the authors discuss issues related to the mis-match, including the non-inclusion of the indirect effect of aerosols or possibility of errors in ocean heat uptake rates. These sources of ignorance, despite your claims to the contrary, are well acknowledged by the community. The uncertainties aren’t a huge source for attribution because we know aerosols cool the climate.
You are right about internal variability, etc; simply mentioning potential issues and saying things are “complex” is insufficient to make your point.
Chris, the hockey stick is a fraud, the IPCC relied on the fraud and the fraudsters, therefore the IPCC is a fraud.
Understand?
Thanks for the contribution.
Sometimes restating the obvious saves time.
Chris,
The controversy between your position and that expressed by Judith cannot be resolved based on logic or any model of reasoning, but these models may help in finding out, where the views really differ.
My own view is that the Bayesian approach allows pointing out, where the essential part of the problem is. I don’t like Italian Flag, Fuzzy logic or any of the other similar approaches as they help more in hiding the source of disagreement than in bringing it as visible as possible. They may serve one side in the case of controversy better than the other.
In the Bayesian inference those explanations are favored that can predict more of the observations without contradicting severely any of them. The ability to predict more is valued even, when other explanations don’t contradict the data. The approach is far from easy to apply and strongly dependent on subjective judgment, but this is a fact of life: Every proposal that claims to avoid those problems does it by hiding the problems, not by solving them. In a sense a disagreement is avoided, when an issue is just put aside, but that’s not a solution unless it can be agreed that the issue is unimportant, which ever way it would go.
Picking models based almost solely on the fact that they do fit the data is of no value, as that can be done for any set of data. Such models have no explained anything in the data, but belong to the infinite set of all other possible explanations, and the infinite set explains every outcome as well. That applies obviously to fits like those of Loehle and Scafetta. None of these models is of use in judging the value of the evidence.
The real problem is in deciding, how much the results of main stream climate science have really explained. The scientists have also worked knowing the data that has been collected before their work is finalized. We know that models can sometimes fit the data essentially as well, but be based on contradictory input on the role of aerosols, as an example. That means that the models have also been built to fit the data. It’s done in an indirect way, as the model builders cannot directly fit to some set of data, but they have done anyway something closely equivalent to data fitting.
Based on the above we know that the climate scientists would have almost certainly been equally capable of modeling and explaining climate developments that differed significantly from the actual – or in other words their approach leaves very much of the observations unexplained replacing explaining by fitting.
The 60 year oscillations appear clear in the data. Many people have told that this may be due to many different reasons from accidental coincidence to regular cyclic oscillations. While all these explanations are possible, the phenomena is still clear enough for being taken as a possible signal of some real underlying phenomenon that has had a significant effect on the climate of last 150 years at least. This belongs in a way to the realm of fitting, but it may certainly be argued that the signal is strong and specific enough to require special attention.
Looking at possible contributing factors it’s perfectly legitimate to look also at the solar system, but giving weight to findings from there requires much better ideas of physical mechanisms that we have seen here recently. Most people seem to think rather that the Earth system itself has in some way the natural oscillatory period (or resonance) of about 60 years. There are other signs of that, but how could we be without other signs, when it’s so visible in the temperature. Real explanations seem to be missing, but on the other hand climate science is hardly capable of describing the dynamics of the Earth system well at the relevant time scale. That capability should be improved, but it’s likely to take time.
As long as we don’t understand the dynamics of the climate system on this important time scale attributing the historical observations is uncertain, and making projections for the future even more uncertain.
======
None in the above tells, what the right climate policy is now. I’m not going into that, I only emphasize that it’s not answered by the above in any direction.
Pekka, the difference between my perspective and Chris’ is how we reason about uncertainty. The Bayesian approach has a well known flaw in terms of how it deals with ignorance. Your statement “The real problem is in deciding, how much the results of main stream climate science have really explained” is exactly the main issue. The IF etc help you decide exactly that. Clarifying the two sides of a disagreement isn’t all that useful when the white part of the IF is very large, i.e. uncertainty and ignorance dominate. For further discussion on this issue, see my article and post on reasoning about climate uncertainty, which is in press and should be posted electronically within the month
http://judithcurry.com/2011/03/24/reasoning-about-climate-uncertainty-draft/
Judith,
As usual my comment started to live its own life, when I was writing it, losing part of it’s internal logic.
My view is in agreement with the observation that you and Chris look at the uncertainty differently. Where I have disagreed with you also previously is in the value of approaches like the Italian Flag, and this is an essential part of, what tried to say. In the way I see the problem of the Bayesian reasoning is cannot be resolved by switching the approach. The limitations can be expressed in the Bayesian formulation as well noting that the outcome is not unique and describing in any of many possible ways the extent of the non-uniqueness. Other approaches are essentially equivalent to some of the crude ways of describing the non-uniqueness. I write crude because all the methods that I have seen (including the Italian Flag) are built to lose also real information. They draw typically a specific line between two alternatives (i.e. between red and white or white and green) although the choice of this line is as uncertain as anything else, and although the transition is almost never abrupt.
In a complex issue, where several different arguments are used, the combined effect of such crudeness in the methodology is usually very bad leading possibly in some cases against even such conclusions that everybody could accept based by a more nuanced approach.
Basically it’s not good to say that: “about this we don’t know anything”, as that leads sometimes to very different conclusion than saying that is is a very uncertain thing, and we not only this little about that. Anther problem with very many approaches is that choice of variables has often a very large influence on the outcome even, when this is not at all obvious, when the issue is not explicitly considered. An advantage of the Bayesian approach is that it may help in handling this problem – or at least noticing it.
My view is that your disagreement with Chris is related to the above issues, and in my view, you and Chris deviate to the opposite directions from, what I think myself. He may prefer handling uncertain conclusions too similarly with almost certain ones, while you don’t want to give for weak knowledge even that value that it deserves with all it’s weakness.
Of course this is just a personal judgment based only on what I have read on this blog (I have no knowledge on the approach of either of you from any other source). Perhaps I shouldn’t pretend to be able to make judgments on this basis, but this is now our common world.
Pekka, you misunderstand my position, which is clearly stated in my article on reasoning about climate uncertainty. I am not sure what you mean by the value of weak knowledge. From the context of science, weak knowledge is weak knowledge, and it does not justify in itself rejecting alternate explanations. In the context of decision making, uncertainty and the relative weakness of the knowledge is important information for decision making.
Judith,
The problems that I have in mind occur mainly at the level of combining knowledge. Technically they are in the rules that are used to combine evidence and to combine uncertainties.
There are questions like: What is the combined value of several independent types of evidence when everyone of them is taken alone too weak to affect conclusions? Or what is the combined uncertainty, when several independent factors contribute to it?
These are well known questions and they have unique answers in probability theory and standard error analysis, but they become difficult and controversial, when PDFs are not known or, when uncertainty is not due to randomness but to lack of knowledge.
Bayesian approach uses well specified formulas, but these formulas contain prior PDF’s and functions describing likelihoods of the observed result for varying values of parameters. The prior is by definition subjective, and the likelihood function is also often determined partly through subjective judgment. These are serious problems, but the approach allows for being explicit on the choices and having argumentation on them.
The alternative approaches are introduced to avoid the difficulties of the Bayesian approach, but they avoid them by replacing theoretically justified Bayesian formulas by some rules of thumb that are known to be false, but have the advantage of being easy to use. This becomes essential, when many sources of information are combined. Under those conditions the known errors of the rules for combining information are not any more benign, but they may lead to totally unjustified conclusions. This is the reason that I don’t like Italian Flag method or any of the other similar alternatives. All of these methods have their own biases. For one method the bias is mostly in the same direction, and the biases may indeed be dominating, when sufficient amount of information is being combined. It may, e.g., happen systematically that major uncertainties in almost irrelevant factors turn out to dominate the conclusions.
The disagreement that I see is not so much in the use of final knowledge of some specific strength or weakness, but in deciding whether the balance of evidence is strong or weak, when it consists of many independent pieces.
Pekka, the Italian Flag doesn’t involve combining evidence per se, it is a device for compiling evidence for, evidence against, and assessing the relative magnitude of uncommitted belief. The methods of combining evidence that use the IF (e.g. Interval Probability, Support Logic Programming) are a separate issue. So they are separate, but not unrelated. I think the IF stands alone as useful whether or not you like interval probability methods, i.e. if the white area is very large, the issue is probably not worth much additional analysis using bayesian methods, interval probability, etc.
Compiling evidence for, evidence against, and assessing the relative magnitude of uncommitted belief is a part of an overall assessment. In that various pieces of information should get their proper weight based on the strength of evidence and on the significance of the particular issue for the overall assessments. All crude simplifications done during the process lose evidence, and they may lose evidence to the extent that the final conclusion is reversed.
The error is most likely in the direction that an important issue supported actually by reasonably strong evidence is turned to one of no weight in making conclusions. This is the likely direction of error, because the methods handle typically weak evidence as no evidence, while a combination of several supporting factors may provide essentially stronger evidence than any of them alone.
The Bayesian approach can be and certainly also is continuously misapplied. What I like in it, is that it’s problems can be studied. The assumptions made are explicit. The assumptions are not always fully understood or reported, as we have seen here in the thread on IPCC AR4 WG1 Figure 9.20, but looking at the analysis they can be recovered. Repeating the analysis with alternative assumptions tells then, how dependent the conclusions are on the assumptions. This is very useful in pinpointing the origins of differing views and in looking for issues that are most critical for the conclusions.
We face quantitative questions, and must tell our best answers to the quantitative questions even, when uncertainties are large and largely due to ignorance. When the quantitative answers are subjective to an significant degree that must also be stated. Objectivity should not be implied, when subjective judgment has affected the results. On this point IPCC reports are not at all as open and careful as they should be. They emphasizes the subjective aspects all too seldom, and fail to discuss the (limited) value of majority views in determining the subjective input. The reports don’t support well people, who wish to understand the implications of the uncertainties. I believe that the main reason for these failures is in the level of understanding that the authors themselves have.
Chris at 1.37
We have previously had a perfectly pleasant exhange of private emails but perhaps you are being overconfident with your comments.
Are you seriously saying that you have built up the expertise and knowledge in your short career to tell Judith Curry that she is making things up and violating physics? Did you REALLY mean to say that?
I am sure she is perfectly capable of fighting her own battles but perhaps you might win more people to your viewpoint if you were to be rather more circumspect in future and not be so certain that the uncertainties have been quantified.
tonyb
Chris at 12.15
Your IPCC link went straight to a reference about the upper oceans. That is a very good place to question the uncertainties and unknowns. Perhaps you could tell me how accurate you believe say the Hadcrut figures are back to 1850?
Totally accurate? Mostly very good? Mostly not very good?Not worth using?
Where does your estimate of their validity come to within the four point spread I have given?
tonyb
The uncertainties aren’t a huge source for attribution because we know aerosols cool the climate
Generalization suggest ignorance ie Black carbon and Organic carbon warm the climate eg Praveen 2011
The atmospheric forcing due to BC and OC exceeded 20 W m−2 during all months from November to May, leading to the deduction that elimination of cook stove smoke emissions through clean cooking technologies will likely have a major positive impact on health and the regional climate.
http://www.atmos-chem-phys-discuss.net/11/21319/2011/acpd-11-21319-2011.html
Chris, “For example, El Ninos don’t cause long-term secular trends in global temperature, an absurd violation of conservation of energy and inconsistent with changes in ocean heat content, the direction of the planetary energy imbalance, etc”
Very true, the ENSO and all the other oscillations just move heat around. It is where the heat ends up that causes potential long term trends, because some areas more easily dissipate heat or tend to amplify its impact. So there is not a violation of conservation of energy if you look more closely at the total picture.
Bob Tisdale makes a interesting point that ENSO does seem to cause steps in SST for parts of the ocean. And not for other parts.
http://i54.tinypic.com/33bmiza.jpg
http://wattsupwiththat.com/2011/07/10/tisdale-on-sst-correlation-with-agw/
“The problem is that you and the WUWT crowd are too gullible and are ready to jump onto any new idea, or at least wave the “this is interesting!” flag, even if it is a complete misapplication of what is known about the phenomenon or devoid of any consideration of physics. The whole point is to cast doubt on the primacy of CO2, rather than think intelligently about the *new* hypothesis, and its explanatory and predictive power. Curve fitting doesn’t do that.”
Like you I believe in the primacy of C02. unlike you, I have faith that over time reasonable people will come to agree with that assessment. Unreasonable people, well no amount of time, no amount of controlling the messaging, will convince the unconvincable. Now, of course when Mann makes some rather horrible mistakes in published science ( the mislocation of proxies, misuse of methods, use of contaminated data) people like you say “the mistake doesnt matter” or science will correct itself. Rather gullible, we continue to see these errors propagated through other papers. I find it odd that people like you are so overly concerned with the rantings of a few cylce nuts (apologizes to my friend Craig) and so underly concerned with similar buffonery in published science. And while I believe in the primacy of C02 and the imperative to do something about climate change, I see no reason to limit what people read, what they publish or what they choose to waste their time on.
Finally, ray makes an interesting point, but its largely a social observation and not an epistemic one. He thinks it’s an epistemic point. He thinks that because he is doing what he considers to be “normal” science, where new twists have to fit the existing paradigm, where if you have a new forcing or new relationship to explore you better show up with code and equations that fit into a GCM. He thinks his point is epistemic, but it’s a social observation.
My guess is that you think that spreading the kind of dis information this article represents will lead to a delay in action. You’d like to close off discussion, focus on the real topic and move on to action? is that about right? That’s a really important question Chris, I’ll suggest you think about it
No one is saying that we should close off discussion, but it would be nice if the discussion should be more focused and intelligent.
I’m quite tired of people like Craig or the scientists in the “swindle video” making up nonsensical arguments and then moving on to the next argument in the laundry list of talking points (on a weekly basis) when it gets ignored or rebutted by serious people. Yet their credibility is recycled by skeptics everytime they make a new point.
Meanwhile, you feel free to go on for a decade about some issues in Mann’s paper, and request that everyone has to defend it indefinitely (regardless of its relevance to the actual discussion…it’s always just a fall-back), and that he is forever an outcast of the honest science crowd.
As I said to Judith, the whole point is to cast doubt, rather than propose any serious *new* explanation and actually defend it. Please don’t try your games on me.
Chris, the hockey stick and climategate demolished trust in climate science.
And here you are making such distrust even more justified.
Chris, you should have said Mann’s papers. He has developed a unique track record.
You may be right in general about the casting doubt motive for many, but there are quite a few that just think the “consensus” has not covered all the bases. It is not unreasonable to believe that feedback to CO2 doubling is not well understood or that the doubling will cause 3 plus W/m2 to be felt at the surface. Where CO2 has the most impact is were there is the least water vapor. So the radiation window is not as tightly limited. If you can filter out the Venusians, Iron Sunners and more fanatical Cyclomaniacs, it is an interesting discussion.
“No one is saying that we should close off discussion,”
Errr…. yes – someone IS saying that we should close off discussion.
Your tired of the Swindle video but you say nothing about the Gore one or the others that are just based on emotion. You don’t see any objectivity issues with that?
I certainly think many videos out there are emotionalized or contain errors, and I’m more than willing to admit them on a case-by-case basis. Of course, videos by politicians and actors or environmentalists are just their own project; people like Lindzen, Tim Ball, Christy, etc do have credentials and a scientific reputation to maintain, and should know better.
Mr. Colose, you write as if the past decade never happened. Those of us who are not scientists have watched with almost unhealthy interest as this argument has played out on several stages in parallel with the scientific theater you are trying to focus on.
A lot of the skeptic arguments are wrong, and some are obviously unscientific. But because there is no organizing force for the skeptics, there is nobody who can put an imprimatur of quality for their arguments. The best of the skeptic arguments seem quite good to me, especially when they are addressing consensus arguments (including scientific papers) that are rushed out to reinforce a political agenda. I refer specifically to work of the self-styled Hockey Team.
Coupled with the systematic attempts to trash the reputations of people like Freeman Dyson and Richard Lindzen has, through your side’s efforts, recast many aspects of the debate as purely political, and a dirty form of politics at that.
It certainly seems to me as though you are saying that videos by ‘politicians and actors are their own project’ to get your side off the hook for slime jobs ranging from the ‘No Pressure’ video and Anderegg, Prall et al, while saying all skeptics everywhere share communal responsibility for sky dragon arguments. That cannot be right.
But alongside the scientific arguments, there have been political, economic and media arguments that have influenced all of us, including consensus scientists.
I’ll limit myself to one example: Do you expect us to ignore the fact that the head of the IPCC sought to suppress revelation of his organization’s error regarding Himalayan glaciers while his consulting firm was bidding to study Himalayan glacier melt? (I have yet to receive an answer to this from anyone on the consensus side of the fence.)
Do you not think that as citizens (who are clearly not scientists) we should not put statements such as yours within the context of the other arguments of the past decade? I’m not even a skeptic–I believe that CO2 clearly influences climate and will continue to do so. But the consensus side has muddied the waters considerably, and to blame the skeptic community for not being amnesiac about it seems a bit much.
Tom,
I think Pachauri was out of line and made bad judgments in his statements. But there was no suppression or other conspiracies, and the IPCC admitted its mistake not too long after.
Concerning what citizens and casual on-lookers should be interested in, I’m really not sure, it probably depends on the question. Personally, I’m interested in atmospheric physics, not scoring points with conspiracies or gotcha games. The difference is some people want to win debates, and they are very rarely the same people who want to help extend our understanding of climate.
Chris, I understand that’s what you want, and I commend you on your focus. But for those of us on the outside looking in, what we remember are the conspiracies and gotcha games from the consensus side of the fence. (I’m not saying that it doesn’t happen on both sides, but the ‘misdeeds’ of those ‘in power’ will certainly stay in memory longer than those of dissidents.) And there are plenty of examples, and the consensus side resolutely pretends that there are not.
“some people want to win debates, and they are very rarely the same people who want to help extend our understanding of climate.”
Chris, you’ve described the hockey team perfectly. Drop in at Climate Audit and check out the recent posts on CRU obstructionism.
Chris
Imo it appears that many of “the folks in your camp” (using your camp descriptions) have frequently taken a bit of knowledge about atmospheric physics and then used that knowledge to try to promote and implementation of governmental policy. The issue of climate change has FAR more to it than simply atmospheric physics and people in “your camp” have been frequently quite naïve about “rational economics” when it comes to addressing potential climate change.
Chris Colose
You stated you are not looking for “doubt”, but rather for “new explanations”.
Here’s one for you, which may not tie directly into the topic here of “cyclomania” or its currently more popular counterpart “carbomania, but yet may still be of interest to readers.
Here is a link to a recent up-date on the CLOUD experiment currently going on at CERN in Geneva by Jasper Kirby, one of the team, which includes top climate physicists and aerosol scientists.
According to Dr. Kirby, they have found that cosmic rays substantially increase the formation of aerosol seeds of clouds.
http://www.youtube.com/watch?v=FkosblR7SI0
Although earlier studies by Henrik Svensmark and Eigil Frijs-Christensen showed a strong correlation between galactic cosmic rays related to solar activity and global temperature, the mechanism was still uncorroborated by empirical evidence and the hypothesis was considered controversial.
A small-scale experiment conducted by Svensmark was too limited to give much hard data.
Dr. Kirby expects that the CLOUD experiment will be able to define the mechanism by which cosmic rays influence cloud production and, hence, our climate.
According to Kirby, CERN was chosen for the experiment because it has a source of cosmic rays (accelerator) and a very clean chamber in which to conduct the experiment.
It should be interesting to see what comes out of this.
It could well fall into your category of “new explanations”.
Max
From my non-scientist understanding of the scientific method, those who formulate a hypothesis have the burden to prove that it is correct and can be replicated. Conversely, other scientists will evaluate this hypothesis to see if it can be replicated. If not, the objective of their research should be to falsify the hypothesis.
I am not aware of any proof based upon empirical data and experimental research that proves the anthropogenic global warming hypothesis (AGW).
From my viewpoint as a lawyer, I am confident that general climate model projections that purport to prove AGW are inadmissible in court proceedings. The information from climate model runs are hypothetical scenarios, not facts. Climate models, as structured, contain numerous assumptions for critical known-unknown data and poorly understood aspects and phenomena concerning climate. Some of these assumptions are now known to be incorrect. These models fail to deal with unknown-unknowns even though the modelers known that they exist. As such, the structure of these models contain speculative components that render them non-probative.
Science is about facts. Climate models cannot produce factual scenarios due to their inherently speculative structure and the speculative nature of their outputs.
Perhaps you can guide to factual proof that supports the AGW hypothesis.
PS: Consider the editorial from CO2Science blog that discusses a recent paper by Dr Trenberth concerning the the inadequacies of state-of-the-art climate models:
http://www.co2science.org/articles/V14/N30/EDIT.php
Hi Mosher
What do you prefer than, the echo of the lone voice in wilderness, being trampled by herd of cyclomaniacs or occasionally whacked with a hockey stick?
Chris
Note the social impact of 10% of the population firmly holding on to one position. The problem with “consensus” in science comes when that 10% is wrong.
Chris Colose says: “For example, El Ninos don’t cause long-term secular trends in global temperature, an absurd violation of conservation of energy and inconsistent with changes in ocean heat content, the direction of the planetary energy imbalance, etc.”
Your statement trumpets your misunderstandings about ENSO. I published a post yesterday that may help you. It’s written at an introductory level, lots of graphs, animations, and it’s titled ENSO Indices Do Not Represent The Process Of ENSO Or Its Impact On Global Temperatures.
http://bobtisdale.wordpress.com/2011/07/26/enso-indices-do-not-represent-the-process-of-enso-or-its-impact-on-global-temperature/
Chris Colose says: “The problem is that you and the WUWT crowd are too gullible and are ready to jump onto any new idea, or at least wave the ‘this is interesting!’ flag, even if it is a complete misapplication of what is known about the phenomenon or devoid of any consideration of physics.”
Since I am the primary author of posts about ENSO, Sea Surface Temperature and Ocean Heat Content at WUWT, I’ll respond to this as well. Your statement expresses your belief that my posts misrepresent ENSO and its impacts on SST and OHC. Yet you have made no attempt to counter my interpretation of what is presented by the SST and OHC data. All you’ve made is a general statement. Please read the post I’ve linked for you above in this comment and advise me on that thread where my interpretation of the data is wrong. When we’re done there, we’ll move on to OHC.
Your conservation of energy claim smacks of the deniers and their second law claims. There is absolutely no reason why ENSO would follow the first law – it is not a closed system.
For that matter the climate is not a closed system. As Nordel andGervet demonstrate theri are amny other energy sources. While none of these are significant on an annual scale, over a century scale they do add up. The models have asumed that any process that the modelers do not understand must not be significant, then fit their models to the data using “sensitivity” much like 19th century physicists used the ether to explain what they didn’t understand about light. At the end of the day the models are really just sophisticated curve fitting.
This paper, while it does not explain warming, does demonstrate a huge gap in the curve fitting of the models.
Cycles can be problematic when dealing with solar system dynamics.
The solar system is a messy place that refuses our rigid rules, Jose got it wrong in 1965 and we still look for regular repeating cycles while not understanding every cycle is different. This is why FFT analysis shows us nothing concrete.
There can be at best “quasi” type cycles that show a basic background trends when it comes to solar system cyclomania.
I could not agree more with the regional aspect of oscillations being extremely important if we want to begin to understand cyclic or pseudo cyclic climate patterns. Tsonis’ 2007 paper I believe, was interesting in that the tropics tend to have a more “cyclic” pattern with the high and middle latitudes response complicated by interaction with other oscillations.
That inconsistent response, especially in the Northern Hemisphere, makes me question high correlations of GTA with astronomical cycles. None of the astronomical cycles during the past few hundred years have the strength to over ride the natural chaotic interactions globally, at least to my knowledge.
So solar grand minima have no effect on climate?
Grand minima most likely do have an impact of climate. I don’t see what I would call a real cyclic pattern in recent minima though. If I were guessing, I would think the reduced UV for a long period impacts deep ocean heat content requiring the long quiet time to make a long term change in climate. Then there are changes in atmospheric ionization that may take a while to cause a pronounced climate change. Synchronization of the minima with internal oscillations probably impact the degree of change. There is a lot of stuff happening.
Now if the new minima happens lead to the discovery of some complex minima cycle, then there could be predictability to climate change.
The discovery has perhaps already happened. Low solar output has been showings it head during recent winters, plus the background quasi cycles can be verified with new knowledge.
http://Www.landscheidt.info
That’s a pretty complex cycle. I just skimmed the article, but that is what I would suspect. Now we just need some solid evidence of how climate really responds.
The solid evidence is happening now. Plus past grand minima cannot be ignored. It might take a few days to take in the detail, but I am happy to respond to any questions.
I don’t think the neutral temperature response is enough evidence. It would be interesting to compare regional responses to see if a down trend may be predictable. The increase in tropics cloud cover may be a clue. The monsoon reconstructions may have a reasonable correlation with cloud cover and minima.
Judith: Excellent focus on a key IPCC weakness.
See numerous links to natural cycles in your post: Scafetta on climate oscillations
Hydrology, River Runoff is a critical area for civil engineering and science.
See Ref at my post 1: and
post 2
Especially see the extensive research by D. Kkoutsoyiannis at ITIA http://www.itia.ntua.gr and their numerous publications
Others study the Nile e.g. Orbital climate theory and Hurst-Kolmogorov dynamics abstract Kondrashov et al. 2005
Is solar variability reflected in the Nile River? Ruzmaikin, et al. 2006
For Southern Africa, WJR Alexander is key with his identification of runoff tied to the ~21 year Hale solar cycle, and exploring barycenter oscillations as the cause. e.g., Alexander et al. 2007
Alexander 2005
Alexander has compiled very extensive original statistics and analyses. He will publish a major hydrology manual later 2011.
Cosmic ray oscillations on climate
See especially papers by Henrik Svensmark, NJ Shaviv etc. See Nir Shaviv presentation.
Note evidence of radionucleotide variations in ice cores and sediment cores.
Gray, L. J., et al. (2010), Solar influences on climate, Rev. Geophys., 48, RG4001, doi:10.1029/2009RG000282.
etc. etc.
Length of Day “LOD”
Analyzing the LOD is another major source for natural cycles which relate to temperature and thus winds etc.
Paul L. Vaughan reviews LOD at WUWT
See dissertation by Gross, Richard. S., Earth Roation Variations – Long Period, in Physical Geodesy, edited by T. A. Herring, Treatise on Geophysics, Vol. 11, Elsevier, Amsterdam, 2007.
Le Mouël, J.-L., E. Blanter, M. Shnirman, and V. Courtillot (2010), Solar forcing of the semi-annual variation of length-of-day, Geophys. Res. Lett., 37, L15307, doi:10.1029/2010GL043185.
Nils-Axel Mörner: Arctic Environment by the Middle of this Century
With references posted and again
A. Mazzarella, “The 60-year solar modulation of global air temperature: the Earth’s rotation and atmospheric circulation connection”, Theoretical and Applied Climatology, Volume 88, Numbers 3-4, 193-199, DOI: 10.1007/s00704-005-0219-z
The Sun’s Role in Regulating the Earth’s Climate Dynamics Richard Mackey, Energy & Environment, V.20, N.1 – 2 / January 2009
Decadal variations in geophysical processes and asymmetries in the solar motion about the Solar System’s barycentre Nikolay Sidorenkov, Ian Wilson, and Anatoly Khlystov, Geophysical Research Abstracts Vol. 12, EGU2010-9559, 2010
Compare the 2009 dissertation: Ensemble Simulations of Atmospheric Angular Momentum and its Influence on the Earth’s Rotation by Timo Winkelnkemper.
Happy cycling!
Dr. Curry
Thank you for the interest as quoted in the opening statement. I have no expert knowledge either in the climate science or computer modelling; I just pursue peripheral elements that I find of some interest, if reliable data is available. My interest in climate started some 2 years ago, after discovering correlation between the Arctic’s magnetic field and solar activity. It may surprise many, there are good data on both, but somehow legitimate science has not arrived there yet; currently I consider geomagnetic field more of a research tool than the true cause. Initially, the solar cyclical activity looked as a good candidate to be the cause of the underlying temperature oscillations, however, after some further investigation I think that the solar activity is only a minor contributor, on the decadal and longer time scale, there are temperature movements, which appear not to be directly linked either to the solar or planetary influence, hence my posts critical of the L & S paper.
I accept view that there is some, but exaggerated CO2 contribution.
It should be noted that the PDO and AMO are only recent discoveries, and parts of the relevant datasets are reconstructions rather than actual measurements. It is currently thought that the nature and origin of the AMO & PDO is uncertain, and it remains unknown whether they represents a persistent periodic events in the climate system, or they are more of transient nature, either way the causes of the oscillations are currently unknown. I have good reason to think that such state of affairs should be somewhat less ambiguous.
I also have strong reservations regarding reliability of all reconstructions reliant on the 10Be data (solar activity, temperature etc.) obtained from any of the Greenland ice core projects (Dye, Gisp, Grip, NGrip etc).
Errata Timo Winkelnkemper (2008) Ensemble Simulations of Atmospheric Angular Momentum and its Influence
hss.ulb.uni-bonn.de/2009/1648/1648.pdf
Cyclomania is well named. NOAA lists 41 climate indices, mostly cyclical. Here are some of them: PNA, EP/NP, WP, NAO, NAO(Jones), SOI, Nino3, BEST longer version, TNA, TSA, WHWP, ONI, MEI, Nino 1+2, Nino 4, Nino 3.4, PDO, NOI, NP, TNI (Trans-Nino Index), AO, AAO, Tropical Pacific SST EOF, Atlantic tripole SST EOF, Atlantic multidecadal oscillation, Atlantic meridional mode, North Tropical Atlantic Index (NTA), Atlantic multidecadal Oscillation Long Version, QBO, ENSO precipitation index…. etc. etc. When faced with this alphabet soup one wonders how much of this is real and how much is manufactured as another “discovery” about climate.
Good post.
You seem to use the word “cyclic” as synonymous with “perfectly periodic” Is that standard?
It implies that there is no short word for something like natural circadian rhythms: for Syrian hamsters (to pick one well-studied system out of many), there is a nearly perfect circadian rhythm (the time from peak temperature to peak temperature is 24 hours throughout the year), but the time of going to sleep and the time of waking up (and the correlated decrease and increase of temperature) varies throughout the year with photoperiod. The word “cyclic” for a system like that is very handy. It is a “limit cycle oscillator with sensitivity to light”, as has been shown in experiments. Physiologically the mechanism is two nearly independent negative feedback loops, with the light affecting one step. Mathematically, it is represented by a system of 10 nonlinear differential equations. It isn’t chaotic: it’s a limit cycle oscillator with a period of 24 hours in the limit cycle, with a daily pulse of light that knocks it off its limit cycle, and the daily pulse of light has a 365.25 day rhythm. The limit cycle with the constant period is observed if the hamsters are kept in constant darkness for a long time.
I agree. Oscillations produce cycles. Cycles do not have to be regular.
The key underlying scientific issue is what is the Null Hypothesis of natural variations when seeking to identify anthropogenic influences?
Ar these “variations”
Cycles?
Oscillations?
Variations? or
Chaos?
Especially when the “variation” is comparable or longer than the time horizon of measurements.
The related issue is what are natural weather extremes and do anthropogenic causes increase those extremes?
How can we quantify “anthropogenic” if we have not quantified “natural”?
My views on tracing the cyclic patterns well enough to establish a forecast method for short and medium range weather forecasting that seems to work out past 7 to 10 days all the way to up to 18 years out. Therefore giving a glimpse of the short term climate trends out a decade or two.
http://research.aerology.com/natural-processes/solar-system-dynamics/
David,
I pointed that out up-thread and no one seemed to consider the idea that a significant part of this is a poor choice in names.
My favorite story about cycles comes from Scientific American Feb. 1989, “Blame it on the Moon”. The focus of the paper was a late Pre-Cambrian (Marinoan) glacial sandstone (Elatina Fm) in Australia that showed layering in rythems of approximately 22 layers per cycle.
Original hypothesis: glacial + 22 units per cycle …. 11 years in the solar cycle.. Yes these are varves, layed down two per year, thus confirming the long term periodicity of the solar cycle.
The Scientific American article said there is another explaination. Back 650 million years ago, the moon was closer to the earth. It’s orbital period around the earth was 22 to 23 days. These layers are seasonal, but tidal; not twice per year, but twice per day cyclic with the nep tides.
It is a great lesson in searching for alternative hypotheses. I don’t have a link to SciAm, but here is a related paper: http://www.setterfield.org/000docs/snowball3.htm
Correction to the above: “These layers are NOT seasonal, but tidal”
The short version of what we see below is as follows: Pretending to science as the global warming alarmists do with their C02-based AGW pseudo-science explanation for global warming and cooling and climate change in general is really juvenile. All of the Chicken Little doomsday prognostications of Thermageddon would be big laugh if not for all of the lies and deceit and the utter contempt with which secular, socialist Western academic hoax facilitators have for the rest of the world is pathetic.
“…Solomon et al. [2010] recently acknowledged that stratospheric water vapor, not just anthropogenic GHGs, is a very important climate driver of the decadal global surface climate change. Solomon et al. estimated that stratospheric water vapor has largely contributed both to the warming observed from 1980-2000 (by 30%) and to the slight cooling observed after 2000 (by 25%). This study reinforces that climate change is more complex than just a response to added CO2 and a few other anthropogenic GHGs. The causes of stratospheric water vapor variation are not understood yet. Perhaps, stratospheric water vapor is driven by UV solar irradiance variations through ozone modulation, and works as a climate feedback to solar variation [Stuber et al., 2001]. Thus, Solomon’s finding would partially support the findings of this paper and those of Scafetta and West [2005, 2007] and Scafetta [2009]. The latter studies found a significant natural and solar contribution to the warming from 1970-2000 and to the cooling afterward…
“In conclusion, data analysis indicates that current general circulation climate models are missing fundamental mechanisms that have their physical origin and ultimate justification in astronomical phenomena, and in interplanetary and solar-planetary interaction physics.”
Scafetta N. Empirical evidence for a celestial origin of the climate oscillations and its implications. JASTP 2010 Apr
OT.
Just noticed this on the Met Office website:
The latest available data subset is HadCRUT3 subset July 2011 release
http://www.metoffice.gov.uk/research/climate/climate-monitoring/land-and-atmosphere/surface-station-records
See this previous post where we discussed at length
http://judithcurry.com/2011/06/29/critique-of-the-hadsst3-uncertainty-analysis/
I like there sense of humor.
Victoria Int A
Last good year – 2007
2001 to 2007 is all -99 – no data
Hi Vuk
It was an interesting thread. As a result of it I am in active dialogue with John Kennedy of the Met office who wrote a critique of the figures. I am also rowing round the ocean next to us taking a variety of SSTs so I can give him some verifiable facts and figures. I think we fundamentally disagree as to the value of the figures back to 1850. :)
tonyb
Wouldn’t a cycle result from a mixture of positive and a negative feedback systems with some lag? Engineers would be much more up on control systems theory. Presumably one could study the various system components and their lag times to figure out the responsible mechanisms.
“The IPCC’s attribution argument assumes that [most] 20th century climate variability and change can be explained solely by external forcing (volcanoes, aerosol, greenhouse gases, solar).”
Judy – If you look at 20th century ENSO, combined with the AMO and PDO indexes you linked to, I think a strong case can be made for the IPCC attribution. A similarly strong case can be made for their attribution of most warming since “mid-century” (i.e., 1950) to anthropogenic greenhouse gas emissions.
On the other hand, if the IPCC had concluded that most warming since 1980 was due to anthropogenic GHGs, or indeed, most warming during many other arbitrarily selected thirty year intervals, that conclusion would clearly be questionable on the basis of the “natural” internal climate fluctuations you mention (I’m assuming that ENSO, AMO, and PDO lack any anthropogenically forced component, although that may be inaccurate, and assuming as well that the magnitude of the internal fluctuations has been substantial in terms of a W/m^2 comparison).
The distinction resides in timescales. From 1910 to 2010, the natural indexes average in such a way as to leave little net temperature effect. On the other hand, many thirty year intervals, as well as intervals of other length, could be chosen in which one or more index moves strongly from negative to positive or vice versa. This is a major reason why the length of model projections will also strongly influence their accuracy. Over very short timescales (one or a few decades), their poor current ability to model the internal dynamics will render them vulnerable to mismatching observations that temporarily deviate from longer trends. On very long timescales exceeding a century, mismatches may grow simply because models are imperfect tools for dealing even with known variables. It is very likely that in their current incarnations, GCMs will do best somewhere in between, and that is unlikely to change until the “natural” fluctuations – periodic or not – can be handled better. Here, though, we have to distinguish between model projections for the future – where periodicities may change – and the use of models to aid understanding of the past century, where we know in retrospect when the major deviations occurred. I would add the caveat that we can’t conclusively exclude other “hidden” drifts that have escaped our attention, but it’s unlikely we have missed anything major.
I think the essence of all the above is the principle that natural variability competes with forced variability in the attribution effort only when the timescales of the two interfere with each other. That has probably only happened on timescales well below a century during the past one hundred years. The two are not competitors over other intervals, even when each is strong, or potentially so.
“if the IPCC had concluded that most warming since 1980 was due to anthropogenic GHGs, or indeed, most warming during many other arbitrarily selected thirty year intervals, that conclusion would clearly be questionable ”
The warming seen was from 1975-2005. This just happens to coincide with the recent warm phases of the PDO and AMO.
Nuff said I think.
TB – The warming during that interval did not correlate with the warm phase of the AMO. There was a better correlation with the PDO, although the PDO itself may be partly anthropogenically forced. In addition, that interval saw significant “global brightening” due to a reduction in anthropogenic aerosols, which additionally supplemented the GHG component of the warming.
I think you may have misunderstood my point. The IPCC did NOT attribute most warming during that interval to GHGs, but rather most warming since 1950. Their conclusion is reasonable because the GHG trend from 1950 to about 1976 was offset by the cooling influences of the aerosols and perhaps the PDO, and from 1976 onward was enhanced by the warming influences of these other factors. Over the entire interval, they largely canceled each other, leaving the GHG trend as the main residual factor.
I don’t think the AMO works like the PDO does. I think the AMO is more of a gradual change and the maximum influence on temperature would be as it went from the bottom of the cool phase to the top of the warm phase which it has recently done. Examine the phases in the following paper as a clearer representation of what I mean:
http://www.meteo.psu.edu/~mann/shared/articles/KnightetalGRL05.pdf
The AMO and PDO were in different phases during the relevant interval.
Because the AMO is a detrended North Atlantic temperature index, its cool phase is out of balance in a cooler direction with a linear global temperature trend, and should tend to reduce a warming trend whether it is in the depth of its cool phase or moving more toward neutrality. I expect the same would apply during its warm phase. The cooling or warming tendency should probably be greatest at peak and trough but persist at some level throughout, and the maximal effects on global temperature might be expected to follow peak or trough after a lag. I don’t know whether this has been formally analyzed, or how that could be done. The article you cite was interesting in its correlation between the AMO and the meridional overturning circulation (AKA thermohaline circulation – THC), but I don’t think it directly addresses the issue of the timing of effects on global trends.
Whether the AMO is a true oscillation/cycle or a Statistical Artifact is a question relevant to the topic of this thread.
“Because the AMO is a detrended North Atlantic temperature index, its cool phase is out of balance in a cooler direction with a linear global temperature trend, and should tend to reduce a warming trend whether it is in the depth of its cool phase or moving more toward neutrality. ”
Yes, and the opposite is true when you go from neutral to the warm phase. So if you have cooler than would be normal and go to warmer than would be normal without the influence what trend would you get? According to the paper linked the AMO was at the trough of the cool period about 1975 and reached or at least was close to reaching the peak of the warm period about 2000. As far as if it is real or not, it is always a good idea to remain skeptical.
Actually I shouldn’t have said yes. If you would have said tend to reduce the temperatures instead of the trend then your statement would have been accurate.
We are discussing an area of some uncertainty because we don’t know the lags between cause and effect. I think, however, that when a climate factor is cooler than neutral, it will create a cooling trend rather than merely a cooler temperature, and this would tend to reduce a warming trend. The concept is analogous to a constant level of CO2 forcing, which, if unchanged, creates a warming trend rather than a fixed warmer temperature until after a very long interval, equilibrium is reached.
Fred, it causes it to be a temperature different from what it would be without it. It depends on where the trend is started if that is a cooling or a warming trend. If the influence is already maximum cooling at the start of the designated trend it can’t possibly cause a cooling trend from that point.
I don’t think that’s correct. A maximum cooling pressure is not the same as a maximum temperature decline. Again, CO2 forcing is analogous. If we double CO2, the maximum warming pressure due to radiative imbalance occurs at the time of doubling, but the temperature declines fairly steadily thereafter for a decade or more and the warming trend doesn’t show significant flattening in those early years but only gradually declines over a period of centuries, finally asymptoting to an equilibrium temperature. As long as the system is not yet in balance, a trend will continue over time.
Imagine a climate in which the only operating factor is AMO cooling (assuming that to be significant), and in the absence of that cooling, the temperature line would be horizontal. If the AMO turns negative, a cooling trend will ensue and continue as long as the negative phase lasts. As the cooling returns toward neutrality, the slope of the downward trend might or might not flatten contemporaneously (probably not immediately, because there would be a lag of some length), but the trend would nevertheless continue in a downward direction until sometime after neutrality is reached.
Now apply this hypothetical effect to an anthropogenic warming trend. It will reduce the trend slope throughout the entire cooling interval. The slope reduction might itself lessen as neutrality is approached, but it would remain a reduction, and if there is a lag, there might be almost no reduction at all until after the neutral point. What we wouldn’t expect to see is merely a reduced warming trend to the trough of the cooling, and an unaffected or enhancing warming trend thereafter.
You are comparing a constant forcing to an oscillation. I think a more suitable comparison would be to an ENSO event where the lag time I have most often read as 2 months although I do seem to remember at least one estimate of 6 months. Perhaps you can explain why you think reaction to SSTs would be significantly different between the two. When the SSTs are at their coolest the impact will be the coolest within the given lag time. Since I was estimating years, I don’t see a matter of months having any real bearing on the situation. When the SSTs warm, even if they are cooler than they would have been without the oscillation, they have still warmed. I don’t see the logic of your argument.
Steven – The AMO is detrended (it is what is left over after the trend is subtracted) – that means that at any point in the cool phase, it is cooler than where it would be if it followed the trend. The effect will always be to turn a slope downward. If the slope is horizontal, it will become negative. If it is positive, it will become less positive as long as the cool phase lasts, even up to the point of neutrality. This is true even if there is no lag, but in the absence of a lag, the downward pressure on the warming trend would diminish past the trough even though it continued to reduce the upward slope. In the presence of a lag, the cool phase might reduce the upward warming slope even after it shifted to the beginning of a warm phase.
If you are suggesting that the extent to which a warming trend is reduced might vary during the cooling phase, I would agree. If you are suggesting that the reduction in the slope of the warming might disappear entirely or reverse, I don’t think that’s possible as long as the North Atlantic is cooler than it would be from the trend slope alone.
You could probably set up a roughly analogous home experiment in which you measured the rate of temperature rise of an object warmed from some constant heat source. After taking the measurements in the absence of any significant external modification (assume that air is such a poor conductor that it will dissipate the heat minimally during your experiment), you can then surround the object with cold water. Obviously, if the water is much colder, the temperature rise will be greatly slowed or reverse. However, what happens when the water temperature is allowed to rise to become only slightly cooler than the warming object? At that point, will the object warm faster, slower, or at the same rate as it would in air? I’ll predict that if you draw the curves, you’ll see it rising slower than without the water (a shallower warming slope) even though the effect is less than with the very cold water. If you get a different result, let me know.
Assuming a flat trend for the purpose of argument.
1C – 0.3C at the coolest
1C – 0.1C as it warms
What trend does this create? Warming or cooling?
Cooling in each case, because in each case there is a continuing flow of heat from the warmer to the cooler object, which would cause its temperature to rise less steeply than if the cooler object were not there. The trend slope will be angled downward less in the second condition, but it will still be downward vs a trend without the exposure to the cooler source.
Also, I’m not sure what you meant by “flat”. If you meant horizontal, the first condition would lead to a trend downward at a certain angle – say 20 degrees. At the second condition, the angle would decline – perhaps to 10 degrees, but it would still be downward (i.e., cooling) vs the horizontal.
If by flat, you meant linearly upward, the upward slope would be reduced in the first condition – e.g., from upward at 16 degrees to upward at say 9 degrees. At the second condition, it would still be reduced, but perhaps only to 12 degrees. At each point, its slope would be less than 16 degrees, and so it would be rising slower throughout the entire interval than if the cooling source were absent. If you want to think of it graphically, draw a red line with an upward slope of 16 degrees to represent the GHG effect. Then draw a blue line with a slope of 9 degrees to represent the first cooling effect. Starting at the second condition, bend the blue line upward so that its slope is 12 degrees. If you extend the red and blue lines, they will continue to diverge, because the blue line is still trending upward slower than the red line.
Well Fred, the SSTs match up with what I am saying. As you can see in figure 4 the normalised SSTs are at their minimum around 1975 just as I said and they reach the maximum at or shortly after 2000 just as I said. In order for you to be correct warming SSTs cause cooling. I should know better then to even ask but would you care to try and explain how warming SSTs cause cooling?
http://www.meteo.psu.edu/~mann/shared/articles/KnightetalGRL05.pdf
Steven – This is getting a bit silly. We are discussing the rate of warming from CO2 and other GHGs as affected by an ocean temperature which in the North Atlantic is warming at a slower rate. If the slowness of Atlantic warming is an AMO effect, that tells us that it is reducing the global warming trend because its slope is below the trend slope. The Atlantic doesn’t have to cool for this to happen but merely warm more slowly than the trend because of a combination of trend-induced warming and AMO-induced cooling that flattens the upward slope without reversing it. I probably won’t continue to belabor this point, but I do think it will be obvious if you step back and think about it, and perhaps graph it out with some sample numbers. I expect it will be obvious to other readers as well.
Judith should have given a mention of the CRI’s president Ray Tomes, a towering intellect and great investigator. Hi maths page on cycles is here:
http://ray.tomes.biz/maths.html
This should go in the headline post even if i can’t get Judy interested in our Maunder Minimum inclusive recreation of the Lean TSI curve from seven cycles linked to terrestrial and celestial cyclic phenomena:
http://tallbloke.wordpress.com/2011/02/21/tallbloke-and-tim-channon-a-cycles-analysis-approach-to-predicting-solar-activity/
Some time ago (2009), I inquired about what TSI really was, and how we know that. As it turned out, satellites measure the central portion of the Electromagnetic Spectrum. The tails outside are apparently dismissed as not having enough energy, even though they are highly variable; how that was determined without measurement was not explained. For long wave EM, OK. For the more energetic and variable short wave, I still have questions about their impact. I do understand that UV (solar corona) interacts with the atmosphere / ozone and that Cosmic Rays may affect low clouds.
http://solarcycle24com.proboards.com/index.cgi?board=globalwarming&action=display&thread=468
Graph: After plowing through every satellite about which I could find data, the result was: Total Solar Irradiance (TSI) is not Total as defined in ANSI/ISO. See Definition in Introduction (Reply # 25). (When SDO flew, the following graph was unchanged):
http://mysite.verizon.net/cache.22/SET_EM_TSI_Coverage.jpg
The entire discussion topic may still be found here: What is Total Solar Irradiance (Really)?
http://solarcycle24com.proboards.com/index.cgi?board=globalwarming&action=display&thread=468
For reference, Electromagnetic Spectrum. Source before modification:
http://lasp.colorado.edu/cassini/images/Electromagnetic%20Spectrum_noUVIS.jpg
Are you unfamiliar with the work of Swanson, Tsonis et al, which I identified on my page The Cooling Myth over a year ago?
PNAS: Long-term natural variability and 20th century climate change , doi: 10.1073/pnas.0908699106; Swanson, Sugihara and Tsonis
Global mean temperature at the Earth’s surface responds both to externally imposed forcings, such as those arising from anthropogenic greenhouse gases, as well as to natural modes of variability internal to the climate system. Variability associated with these latter processes, generally referred to as natural long-term climate variability, arises primarily from changes in oceanic circulation. Here we present a technique that objectively identifies the component of inter-decadal global mean surface temperature attributable to natural long-term climate variability. Removal of that hidden variability from the actual observed global mean surface temperature record delineates the externally forced climate signal, which is monotonic, accelerating warming during the 20th century.
Supporting Information (pdf)
We discussed this previously on this thread. Its a paper that I definitely like
http://judithcurry.com/2011/01/04/scenarios-2010-2040-part-iii-climate-shifts/
Judith: Your Italian flag analysis seems reasonable except for issue of oscillations vs. cycles. If there are true cycles with a fixed period of the amplitude suggested by L&S, they are likely to show up in a significant number of proxy records. If the cycles are transmitted through space, there will be observable radiation changes with this period. Useful predictions are made for the next decades. The white region of the Italian flag should shrink with time. If one interprets L&S’s work more broadly – as characteristic oscillations with a variable frequency associated with the chaotic behavior of the ocean – almost the whole Italian flag should be white and will remain likely remain so. Perhaps the authors would be willing to define whether they are proposing cycles or oscillations.
The tricky part of this is that, while chaotic behavior can appear quite cyclical the opposite is also true – complex cyclical behavior can in fact appear compltely chaotic. Worse, while statistics can help sort the two, in many case one can never be certain whether you are looking at choatic data or complex cyclical data.
Term ‘cyclomania’ was apparently coined by solar physicist Ken Schatten, with some track record in predicting solar cycles, who was apparently suggesting a return to the advancing glaciers of the Little Ice Age due to a Maunder Minimum type ‘Gleissberg minimum’. It was applied to countless attempts to model solar cycles to what basically comes down barycentric properties of the solar motion.
I earned epithet of ‘cyclomaniac supreme’ some two-three years ago due to my publicising a model based on electro-magnetic and not gravitational basis (see my post
http://judithcurry.com/2011/07/25/loehle-and-scafetta-on-climate-change-attribution/#comment-90560
My suggestion that the planetary magnetospheres’ reconnections are reflected back to the sun’s magnetic field (daily measured by Stanford University at the Wilcox solar observatory) , rather then estimated sunspot number, gave my model of the magnetic solar oscillations one of the highest correlations in the natural world, where no previous physical link was established. http://www.vukcevic.talktalk.net/LFC2.htm
Link between solar magnetic field and magnetospheres (magnetic ropes or clouds) is not disputed, but the possibility of a feedback currently is.
Its simplicity and accuracy has not gained me any friends in the solar academia. So ‘ideas fratricide’ within the climate science community is not unique.
Vukcevic,
Interesting how the rotation of the sun and all the other planets but 3 are in sequence to one day in rotation.
The magnetic repulsion of + to + and – to – with the suns field stronger at the front of the planet and weaker at the back of the planet in a rotational setting. The distance between the + and – at extremely close quarters at the center has very little influence in the field, the same with extremely long distance, the energy is too dissipated.
Planets and suns never started at a stopped position. They always had an energy storage advantage that the sun is just helping with a slight nudge as the rotational field energy passes.
See Bastardi & Corbyn on natural cycles
The success rate by Piers Corbyn at WeatherAction evidences that much natural variation and predictive cycles/oscillations is missing from the Met Office modeling (with similar lack in the IPCC models.)
The kind of cycle-based predictions is similar to studies such as these which claim exact prediction of S&P 500 returns based on change rate of number of 9 year olds in the USA – right before it stops working. I’m sure, like some peripheral solar arguments, a cycles fan could justify this on the basis of demographics.
RB
The UK bookies would beg to differ with you over predictions by Piers Corbyn:
May I recommend that your more carefully examine these natural cycles that the UK Met office has been ignoring that Corbyn has been so successfullly leveraging.
David,
One hundred times zero is still a zero.
Still bitter IPCC’s predictions are total crap?
Ed Fix describes his cycle analysis method at Tallbloke blog: Solar activity simulation model revealed.
Fix’s paper “The Relationship of Sunspot Cycles to Gravitational Stresses on the Sun: Results of a Proof-of-Concept Simulation”.
can be previewed in:
<a href=http://www.elsevierdirect.com/ISBN/9780123859563 in Ch. 14 p 335 of Dr. Donald Easterbrook, ed. (Elsevier, 2011) e-book (hardcover to follow in Sept) (http://www.elsevierdirect.com/ISBN/9780123859563/EvidenceBased-Climate-Science).
Fix models the solar acceleration vs the barycenter as a damped oscillator and obtains amazingly good predictions of the solar sunspot cycles. I highly recommend Fix’s paper. I expect this will revolutionize solar cycle modeling and predictions (compared to the dartboard of previous models). (David Archibald earlier posted Fix’s prediction graph at WUWT)
Errata: Ed Fix The Relationship of Sunspot Cycles to Gravitational Stresses on the Sun: Results of a Proof-of-Concept Simulation”. Ch 14 p 335 of Dr. Donald Easterbrook, ed. (Elsevier, 2011) e-book
can be previewed at: ReadInside
Search for “355” or “barycenter” or “sunspot cycles”
Try again:
http://elsevier.insidethecover.com/searchbook.jsp?isbn=9780123859563
Took me 5 minutes to find an error on page 100. hehe. I always check page 100 first.
Do you see it?
I prefer to sift for nuggets in the gravel.
(It is cost effective to recover 0.1 g gold per ton of alluvium in a high throughput mobile plant.)
It is good to recognize that the ocean is chaotic and possesses no regular cycles. The 60-year AMO/PDO oscillation has no predictive value, and should not be extrapolated forwards as though it does. I hope this article will mean people will refrain from such extrapolations as they recognize that the ocean is too chaotic to forecast such oscillations even a few years ahead (see El Nino for another example).
“The thread on the recent Loehle and Scafetta paper (here and WUWT) have spawned the term “cyclomania” […[“
Certainly not a new term.
The usual goofy misinterpretations of PDO.
I don’t understand CC’s criticism that skepticism denies physics. Only a very small number of skeptics would argue about the basic GHG effects of CO2. All other things being equal, higher CO2 would contribute to higher temperatures. But all other things are seldom equal. More importantly, climate sensitivity to CO2 cannot be derived directly from physics principles, and this is the issue about which most skeptics are skeptical. The evidence for high sensitivity amounts to correlation and lack of ideas about possible causes other than CO2. It is puzzling to outsiders how some (but certainly not all) climate scientists are so thoroughly certain on the basis of this type of evidence.
Stephen,
CC is just sticking to the dogma that requires simple answers to complex questions to help the faithful.
I no longer trust Leif Svalgaard.
“So arguments that LS inadequately makes […] doesn’t make disappear this whole issue of natural variability on decadal and multidecadal time scales. Alot more effort needs to be expended in this area. […] not just global analyses […] is needed.” “
The effect of aggregation criteria on spatiotemporal pattern demands immediate attention by serious, capable people.
“Data analysis, theory, and model simulations are needed to explore this issue.”
Data exploration:
Absolutely.
The other 2?
Cart before the horse.
We can’t afford to spend the precious funding on garbage computer abstractions (based on patently untenable assumptions).
“So the bottom line is that I regard the issue of documenting, understanding, and predicting decadal and multidecadal climate variations associated with natural variability to be of paramount importance”
Let’s focus on careful data exploration, which MUST PRECEDE sensible conceptualization. We have a responsibility to get the necessary sequence right.
“So at Climate Etc., we will continue to discuss the attribution issue and seek to explore the unknown unknowns associated with natural climate variation on decadal to multidecadal timescales.”
I sincerely hope this signals “back to work” from the endless barrage of unaffordable psych of persuasion & philosophy distractions.
Appropriate focus on the important task at hand would be a welcome development.
Regards.
Paul, ‘LS’ refers here to Loehle and Scafetta, not Leif Svalgaard. If Judith used L&S to differentiate from LS it would be helpful, given the ongoing debate at WUWT between these protagonists.
http://wattsupwiththat.com/2011/07/25/loehle-and-scafetta-calculate-0-66%c2%b0ccentury-for-agw/
I assure you there has been no misunderstanding here tallbloke. (Please reread – thank you.)
Prof. Boris Komitov has written several papers on Sun and Climate cycles.
http://www.astro.bas.bg/~komitov/
It’s a clock even John Harrison couldn’t figure. There are rhythms, eternally subject to spatiotemporal chaotic changes. He, at least, had some things constant, and others for which he could compensate. Climate? No sale.
====================
Judith,
Many researchers look for a cycle to have a pattern to build off a model.
The nature of the beast is that cycles will have to eventually fail over time due to the slowing of the planet and sun and as the distance spreads.
Regardless of attribution, a history (of whatever length) of regular changes makes for a better probable return on betting investment than deciding to pick a favorite “driver” and stake your whole wad on that.
The difference oscillations/cycles is not clear. IMO, it’s the same. Are these oscillations or cycles:
http://solarscience.msfc.nasa.gov/images/bfly.gif
Edim,
That is an excellent question. To me the approximate 11 year solar cycle is a real cycle even though its period varies somewhat unpredictably, because it is likely to continue be reasonably predictable. The changes in sunspot numbers per cycle I can’t define. They may be the result of a complex orbital cycle, some what influenced by a complex orbital cycle with a chaotic internal component added, just a chaotic response to the 11 year solar cycle or magic, but I would not call them a cycle or an oscillation.
Oscillations to me are dependent cyclic events. They may or may not continue in a predictable pattern. ENSO is a great example. You can’t predict that there will be a la nina or El Nino event in March 2032, but there will probably be about an equal number of la ninas and El ninos until then. Most of the atmospheric/ocean oscillations are called that for that reason, they will probably happen, but no guarantees if, when and how much.
“The IPCC’s attribution argument assumes that 20th century climate variability and change can be explained solely by external forcing (volcanoes, aerosol, greenhouse gases, solar).”
I’m trying to square your quote with what the IPCC report actually says. For example in Chapter 9 Section 9.1.1:
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch9s9-1.html#9-1-1
“Climate change may be due to internal processes and/or external forcings. Some external influences, such as changes in solar radiation and volcanism, occur naturally and contribute to the total natural variability of the climate system. Other external changes, such as the change in composition of the atmosphere that began with the industrial revolution, are the result of human activity. A key objective of this chapter is to understand climate changes that result from anthropogenic and natural external forcings, and how they may be distinguished from changes and variability that result from internal climate system processes.”
Right there at the start of the Chapter on Detection and Attribution there’s a discussion of the importance of integrating natural, internal variability into attribution studies. In fact that would be a key objective of the chapter.
There’s also a section on remaining uncertainties
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch9s9-4-1-8.html
In which they state
“A further source of uncertainty derives from the estimates of internal variability that are required for all detection analyses.”
So, on the face of it your statement seems to be an inaccurate summary of what the IPCC said and did. However, I know it’s difficult to distill a nuanced position down into a single sentence, so it would be interesting to see your position more fully explained. What am I missing here?
See also Section 8.4 Evaluation of Large-Scale Climate Variability as Simulated by Coupled Global Models which deals with (amongst others): NAM, SAM, PDO, NAO, AMO, COWL, ENSO, QBO and MJO.
And parts of Chapter 3 which disucss effects of some modes of variability on surface temperatures.
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch8s8-4.html
The IPCC report lists all these possible mechanisms, but I interpret Judith’s comments to tell that she doesn’t believe that are given proper weight in the actual attribution. This may be a question to look at more carefully.
The IPCC is essentially a big list of references it doesn’t do any attribution itself. The actual studies on which the IPCC is based do factor in internal variability. There might be weaknesses in that approach, but if so, what are they? And if so, the statement that “The IPCC’s attribution argument assumes that 20th century climate variability and change can be explained solely by external forcing (volcanoes, aerosol, greenhouse gases, solar).” is wrong or misleading.
I agree Fred it is getting silly. So square what you are saying with what the authors of the paper said:
“The simulated temperature changes associated with
THC variability cannot fully explain the 0.6C of 20th
century warming seen in both global and Northern Hemisphere
mean temperature [Folland et al., 2002], but are
large enough to modify estimates of the rate of anthropogenic
climate change”
The authors are making the same point that I tried to make in my comments to you, and everything I stated above emphasizes that very point – if the THC/AMO changes affect the slope of a warming trend, they must be accounted for in estimating the anthropogenic contribution. They can be presumed to have reduced the slope during the interval from about 1965 to 1995, because their detrended values were those of a cooling. During that particular interval, therefore, the anthropogenic contribution should be adjusted upward to correct for the AMO effect (assuming it was more than very minor on a global scale).
That requires a fairly tortured reading of that paragraph Fred. Now square what you say to what the paper they reference says:
“Similarly, Figure 11 shows that the
change in the occurrence of frosts (defined as near surface
temperature below 0!C on a given day) is also strongly
affected by the NAO. There is a much more substantial
reduction between 1965 and 1995, as observed, when the
NAO change is added.”
So next question: How can something that is slowing warming decrease the frosts? They clearly compare warming without the NAO and warming with it and the warming with it has substantial reduction in frost days in comparison. Figure 11. The also compare the warming of the north Atlantic with global warming and the rate of warming in the Atlantic is much greater then that of the world in general. Figure 12.
But you are right, this is getting silly, and I am done.
http://www.gi.alaska.edu/~bhatt/CJC/Parkeretal_2007.pdf
I probably should point out that the frost days I am refering to are from a climate model, the 3rd Hadley Centre atmospheric model. When I say add in the NAO that is exactly what I mean. They run the model without it and the run the model with it and the model run with it comes up with fewer frost days. Apparently there are a bunch of us all reading the implications of the AMO incorrectly.
I see where I did make an error. That wasn’t the paper they referenced. Still I think the paper makes a good enough reference for this argument.
Steven – I’m not critical of careless errors of the type we all make, but more critical of your persistence in attempting to justify a careless assumption that started this dialog. I hope you will go back and seriously consider the principles I enunciated that explain why any AMO cooling below the observed trend, to the extent the AMO has any effect at all, must be keeping the trend from being higher than it would be without the AMO effect, even when the discrepancy has become small. (Also, remember that detrending subtracts an observed trend from a dataset and not a hypothetical trend that might have occurred in the absence of the data in question. A “cool” AMO signifies a value less than the observed trend).
Regarding the paper you’ve been citing, the authors were making a general statement about an entire century of both warming and cooling AMO/THC phases, not specifically to the cooling phase of about 1965-1995, when the effect would have been to reduce the trend slope. (The NAO is a separate phenomenon, although all oceanic/atmospheric circulation patterns in the North Atlantic interact with each other).
Yes, I always assumed the NAO was part of the AMO due to the areas affected proving the law of assumptions. Fred, I have always agreed that the AMO will produce lower temperatures during the cool phase but I still disagree regarding trends. The graph of SSTs in figure 12 I refered to still indicates exactly what I was arguing. The fact that someone states the AMO can account for at least some of the 20th century warming and that AGW numbers would need to be revised indcates to me they are talking about recent warming. The study that was the subject of a post on this blog stated it contributed to the warming. Perhaps it would help if you could post a link to something published to support your position. When I find a paper that states it in such a manner that it can’t possibly be interpreted any way other ten how it is meant I will get back to you. Also, I am not stubborn. If I see a reason to change my mind I will. I haven’t seen that reason as of yet.
Judith Curry
This may be OT here, but what do you make of this recently published study by Spencer & Braswell?
http://www.mdpi.com/2072-4292/3/8/1603/pdf
Max
We are on a hot spot: 1. Natural cycles, which are 2. astronomical and 3. exist on a millenium, centennial, multidecadal and decadal timescale.
We can blame the IPCC, in particular Mrs. Hegerl (AR4 chapter 9) and Mr. Forster (chapter 2) of ignoring astronomical cycles, based on opinions stipulated by 3 shallow insufficient astronomical papers from the Belgian Louvain university. Regrettably to say so…….
The MOST IMPORTANT CYCLE, determining the climate over centuries still
awaits discussion, because it was overlooked and is not yet available in English (sorry folks, I am slow to translate….) but next spring, the time will be there…
This cycle can easily be detected by looking into history: Current warm period (21 Cty), before LIA (17 Cty), before MWP (13 Cty) before Dark Age Period (9 Cty), Roman Warm period ……and so forth…, even further into the past: Daansgard-Oeschger events, tempeature fluctuations during the last Interglacial (Eemian)……. there must be an astronomical cycle, with which these periods can exactly be determined. At present, folks: A few
months more only in German (booklet ISBN 978-3-86805-604-4, Title: Das Ende der globalen Erwaermung) , please wait for next spring and the puzzle pieces will be put in place for all of you.
Loehle and Scafetta themselves haven’t detected this multicentennial cycle yet and remain with multidecadal cycles (nothing to say against this) and reckon that the unexplained 0.6 C temperature increase should be anthropogenic, because they, at the moment, cannot see anything else…….least a multicentennial cycle…. we will get in touch and then, into depth…. only a few months more…and AGW will hopelessly be defeated….
For those who want a clue: The Earth’s orbit is not a simple line, but
a WINDING SPIRAL, winding around the mean progressive orbit path, and these windings have different distances to the Sun and slowly move from
far-out to close-to the Sun and further forward, thus producing a (presently) 4-centennial cycle from cold to warmer climes……
There is a lot more to discover in the real trajectory of the Earth’s orbit….
Yours “weltklima” JSei.
Joachim Seifert
Here is the downloaded write-up to your book The End of Global Warming with my (rough) translation to English.
Das Ende der globalen Erwärmung
Berechnung des Klimawandels
1. Auflage 2010
108 S. Taschenbuch ca. 14,8×21 cm 160 g
Pro BUSINESS Verlag
ISBN: 978-3-86805-604-4
[Translation]
It will be interesting to read your book and to see which scientific studies and empirical evidence you are citing as regards the cause of past climate change and the projection for the 21st century.
Rather than waiting until spring of 2012, I will get a copy in German.
Max
I have added the parable of the blind men and the elephant to my poster graphic about myopic lack of practical intelligence on both sides of the silly climate war:
http://i.minus.com/il0yia.jpg
“No, so holp me Petault, it is not a miseffectual whyancinthinous riot of blots and blurs and bars and balls and hoops and wriggles and juxtaposed jottings linked by spurts of speed: it only looks as like is as damn it; and, sure, we ought really to rest thankful that at this deleteful hour of dungflies dawning we have even a written on with dried ink scrap of paper at all to show for ourselves, tare it or leaf it, (and we are lufted to ourselves as the soulfisher when he led the cat out of the bout) after all that we lost and plundered of it even to the hidmost coignings of the earth and all it has gone through and by all means, after a good ground kiss to Terracussa and for wars luck our lefftoff’s flung over our home homeplate, cling to it as with drowning hands, hoping against all hope all the while that, by the light of philosophy, (and may she never folsage us!) things will begain to clear up a bit one way or another within the next quarrel of an hour and be hanged to them as ten to one they will too, please the pigs, as they ought to categorically, as, strickly between ourselves, there is a limit to all things so this will never do.” -James Joyce (Finnegans Wake 1939)
Paul Vaughan | July 28, 2011 at 10:19 am | Reply
I assure you there has been no misunderstanding here tallbloke. (Please reread – thank you.)
As JC says “So arguments that LS inadequately makes their case” implies that she means L&S, so your throw-away reference to me seems [true to style] oddly out of place.
Dear Max ,
Indeed, you will be amazed to read about this full cycle (790 years)/half
cycle (395 years from warm to cold climate and vice versa). All based on
one new astronomic cycle – book calculations can be followed by everyone, complete transparency.one new astronomic cycle – book calculations can be followed by everyone, complete transparency.
The approach is unbelievable amazing: When I started to apply this
astronomic approach onto the paleoclimate I was able to exactly calculate
cycle lengths and temperature amplitudes of Dansgaard-Oeschger-events and of the last Eemian interglacial.
There is no other literature on the market which calculates exactly the temperature swing solely by knowing the cycle length or vice versa: Calculating the cycle lengths by solely knowing the temperature cycle amplitude. If the paleoclimatic cycle is 2,200 years, then the temperature swing amplitude is 6 C.
The present ampltude of today show a temperature increase until 2000, having reached the top plateau of the 21. century since, the temperature will remain flat
on the cycle top for another 30 years and will go down towards the new cycle cold bottom as the new LIA of the 25 Century……
Mr. Max Manacker, I am waiting your appreciated opinion……..
your “weltklima” JSei
No doubt about it, because no other climatic analysis is capable of exactly calculating these astronomic and climatic interrelations……
So he is the head of the organization. He flat out denies the error. No suppression? Really?
Joachim Seifert, Institute of Power Engineering, Technische Universität Dresden, Dresden, Germany?
If so, could be interesting.