The BBC’s Richard Black Engages in “Goldilocks-Picking”

Guest post by David Middleton

From the BBC…

Climate: Cherries are not the only fruit

Just about the most predictable event of the week was the tempest of opinion created by the analysis of global temperature changes published in the Proceedings of the National Academy of Sciences (PNAS) on Monday.

As we (and a number of other mainstream news outlets) reported, Robert Kaufmann and colleagues analysed the impact of growing coal use, particularly in China, and the cooling effect of the sulphate aerosol particles emitted into the atmosphere.

They concluded that with a bit of help from changes in solar output and natural climatic cycles such as the El Nino Southern Oscillation (ENSO), the growth in the volume of aerosols being pumped up power station chimneys was probably enough to block the warming effect of rising greenhouse gas emissions over the period 1998-2008.

For some commentators, such as the UK Daily Mail’s Christopher Brooker, this was further proof that the “climate scaremongers” had got it wrong…

[...]

Cherry in the pie

One thing that everyone in the climate blogosphere seems to agree on is that the best fruit in the world is the cherry, judging by the number that are picked.

And the Kaufmann paper has brought a few more down from the tree.

The Global Warming Policy Foundation (GPWF), the UK-based pressure group, said researchers “tweak an out-of-date computer model and cherry-pick the outcome to get their desired result”.

To which the opponents’ rejoinder is, and long had been: “well, choosing 1998 as the baseline is cherry-picking, to start with”.

To illustrate the point, I’ve been through a quick exercise using the approach that groups such as GPWF favour – and that Kaufmann’s research group adopted – of using annual temperatures rather than any kind of smoothed average, and looking for the temperature change over a decade.

I took the record of global temperatures maintained by Nasa’s Goddard Institute for Space Studies (GISS) which is one of the three main global datasets, and calculated the rate of change over each of the most recent 10 decades – ie, 1991-2001, 1992-2002, and so on up to 2000-2010.

I’ve summarised the results in a table on this page. What it basically shows is two things:

  • the numbers vary quite a bit from year to year; and
  • all but one give a temperature rise – the only one that shows a small drop being 1998-2008.

Seeing as it’s logically impossible that the world warmed between 1997 and 2007, cooled between 1998 and 2008, and warmed again from 1999 to 2009, one conclusion you might reach is that using annual temperatures is not a sensible thing to do as it gives you a set of answers that does not make sense.

… which is why most scientists use the running mean approach.

[...]

BBC

Mr. Black seems to be suggesting that Figure 3 from Kaufmann is a cherry being picked by climate realists…

While he thinks that GISTEMP is the “tree”…

Well, I say that Mr. Black is Goldilocks-picking. Mr. Black asserts that it is cherry-picking to use 1998 as a starting point and that the starting point must be 1880. What’s so special about 1880 (apart from it being the start of the instrumental record)?

First off, let’s have a look at a few “cherries.”

Here is the HadCRUT3 global temperature anomaly (GTA) for 1977-2010 plotted with the GTA for 1911-1944…


HadCRUT3 Global Temperature Anomaly 1911-1944 & 1977-2010

Here’s the HadCRUT3 Northern Hemisphere temperature anomaly for 1976-2010 plotted with a non-carbonated interval from the Medieval Warm Period (Moberg et al., 2005)…


HadCRUT3 Northern Hemisphere 1976-2010 & Moberg 863-897

In both examples, the slopes are statistically indistinguishable.
The 66-yr period from 1944-2010 is pretty well indistinguishable from the first 66 years of three different century-scale cool-warm-cool cycles from Moberg’s Medieval Warm Period reconstruction…


HadCRUT3 global 1944-2010 & Moberg NH 831-930, 961-1050, 1038-1138 (Yes, I know I should have used HadCRUT3 NH… I just don’t have a display handy).

The peak of the Modern Warming is, at most, 0.1 to 0.2°C warmer than the peaks of three comparable, non-carbonated, intervals of the Medieval Warm Period, consistent with a net climate sensitivity of ~0.5°C. However, that difference is probably not statistically meaningful.

  • The error bars of all of the data sets are greater than the differences between them.
  • The proxy data show the MWP to be warmer than the late 20th century.
  • The proxies invariably have a lower resolution than the instrumental data; thus the amplitude of the proxy time series is attenuated relative to the instrumental record.

This means that the late 20th century warming might have been slightly warmer than the peak of the MWP. Almost all of the potential error is in the direction of magnifying the warmth of the Modern Warming relative to the MWP, so the odds are that the modern warming is very comparable to the Medieval Warm Period.

Since Mr. Black would probably say that the Medieval Warm Period is another “cherry,” let’s go back another 1,000 years, or so.

Ljungqvist, 2009 and HadCRUT3 NH

What happens if I project the polynomial trend-line a few hundred years into the future?

It starts looking like a cyclical pattern doesn’t it?

One of the “problems” with the way climate data are handled is in the obsession with applying linear trend lines to non-linear data.

A Sine wave has no secular trend…

Sine Wave (From Wood For Trees)

But… What happens if my data represent only a portion of a Sine wave pattern?

A partial Sine wave apparently has a very significant secular trend.

The r-squared of a linear trend line of this partial Sine wave is 0.88… 88% of the data fit the trend line. This implies a very strong secular trend; yet, we know that in reality Sine waves do not have secular trends.

If we take the entire HadCRUT3 series and apply a linear trend line, we get an apparent secular trend…

HadCRUT3 Temperature Anomaly 1850-2009

The r-squared is 0.55… 55% of the data fit the secular trend. This implies that there is a real long-term warming trend.

What happens to that secular trend if we expand our time series like we did with the Sine wave?

The apparent secular trend vanishes in a puff of mathematics…

Moberg et al., 2005 Climate Reconstruction

How can such a clear secular trend vanish like that? The answer is easy. Each “up hill” and each “down hill” leg of a Sine wave has a very strong secular trend. Unless you have enough data to see several cycles, you don’t know if you are looking at a long-term trend or an incomplete cycle.

Using the GISP2 ice core data from central Greenland we can see that over the last 50,000 years, there have been statistically significant warming trends…

GISP2: 50 kya to 1855 AD

GISP2: 1540 AD to 1855 AD

GISP2: 1778 AD to 1855 AD

And there have been cooling trends of varying statistical significance…

GISP2: 10 kya to 1855 AD

GISP2: 3.3 kya to 1855 AD

What does all of this mean?

It means that the Earth’s climate is cyclical. It means that the climate changes we’ve experienced over the last 150 years are not anomalous in any way, shape, fashion or form. And it means that the Mr. Black and the other warmists must “Goldilocks-Pick” their data. Too short of a time series yields no warming trend and too long of a time series also yields no warming trend. The time series must be “just right” in order to show an anomalous warming trend.

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103 thoughts on “The BBC’s Richard Black Engages in “Goldilocks-Picking”

  1. > What happens if I project the polynomial trend-line a few hundred years into the future?

    You torture the data until it tells you what you want. Polynomial fits are generally completely useless for foreward/hindward projections. I tend to look at the end points of the range they cover with a lot of skepticism.

    How many years forward does the fit have to go before the temperature goes below 0 K? What happens if you increase the order of the polynomial by one? One end will show an upward trend – it shouldn’t take much of a projection to get to boiling.

  2. So giving the rampant cherry-public often seen here – are you formally saying that cherry picking is inherently wrong?

  3. Climate change cycles seem to average about 1000years peak to trough, ie. 2000 year cycle length. Taking a small section 150 years long does not provide any idea of what is going on only that you have a trend, of either direction, which you naturally call CAGW.

    Considering the great variation that atmospheric CO2 has had from 1000’s of ppmv to 300 ish ppmv, with no parallel change in climate one wonders where Black et al get their mad ideas.

  4. Excellent piece. This illustrates why the hockey stick graph was so much propaganda. There is no interpreting current climate trends without a correct context.

    The predictable observation from the article is that the warmists are scrambling to explain the flattening. Expect this to get much worse if we are indeed entering another little ice age. And help us all when we return to our most ‘normal’ temps which is true ice age conditions.

    Even when a true ice age reappears, the faith of the religion of man made global warming will require convolutions stating the warming is still continuing, it’s just being masked. Then like any chaotic system the emphasis will switch and the cooling will be man’s fault again.

    Or maybe the religious faithful will look at this little article and realize we are along for the ride for the most part.

  5. Mr Black’s understanding of science is about the same as my understanding of Mandarin Chinese – nil.

  6. They concluded that with a bit of help from changes in solar output and natural climatic cycles such as the El Nino Southern Oscillation (ENSO),..

    Since the ENSO and its atmospheric component Southern Oscillation indices are highly correlated ( http://en.wikipedia.org/wiki/File:Enso-soi.png ) and having found what appears to be a driver modulating the SOI index all major indices (PDO, AMO and ENSO) appear to have common type of modulation caused by natural sources as displayed here:

    http://www.vukcevic.talktalk.net/A&P.htm

  7. I my opinion this paper is another example of how easy it is for climate modelers to adjust their models to apparently fit the data. These models have huge uncertainties in the parameters and by adjusting them any outcome is possible.

    These climate computer modelers do not realize that a valid model should be able to reconstruct the patterns of the climate at multiple scales and forecast them to be credible.

    As extensively proven in my paper

    N. Scafetta, “Empirical evidence for a celestial origin of the climate oscillations and its implications”. Journal of Atmospheric and Solar-Terrestrial Physics 72, 951–970 (2010), doi:10.1016/j.jastp.2010.04.015 PDF

    The climate system is clearly characterized by a 60-year cycle. We have seen statistically compatible periods of cooling during 1880-1910, 1940-1970, 2000-(2030 ?) and warming during 1850-1880, 1910-1940, 1970-2000.

    This 60-year cycle goes back for centuries and millennia as also found by Knudsen et al (“Tracking the Atlantic Multidecadal Oscillation through the last 8,000 years”, Nature Communications, 2011, [http://www.nature.com/ncomms/journal/v2/n2/full/ncomms1186.html]):

    It is overwhelming that the climate system is characterized by a 60-year cycle. The cooling observed since 2000 is perfectly compatible with this cycle.

    So, the issue would be where were the Chinese sulphate aerosol particles during the period 1880-1910 and 1940-1970?

    Note that the Kaufmann’s paper is very careful in keeping this 60-year cycle out of consideration by starting the analysis of their forcings in 1950 and running the climate model only since 1999 up to 2008 (?), and adding huge errors bars up to +/- 0.2 C.

    Moreover, years ago China changed its policy because of the bad ambient air quality and from 2005 on all new installation have a state of the art desulfurization treatment. Sulfur is very likely going down since five years.

    Finally, what happened to the data from 2008 to 2011 where the divergence data and model would be more drastic?

  8. If aerosols pumped out by the Chinese are sufficient to pull down the global temperatures such that they counter-act the warming caused by CO2 then presumably the point at which they are most concentrated is a frozen wasteland?

    One thing I can say for certain: Richard Black is an aerosol (just be careful how you say it….)

  9. From the NASA Goddard site FergalR linked to above:

    “Image above: Sun-blocking aerosols around the world steadily declined (red line) since the 1991 eruption of Mount Pinatubo, according to satellite estimates. The decline appears to have brought an end to the “global dimming” earlier in the century. Credit: Michael Mishchenko, NASA”

    Increasing or decreasing aerosols? I wish they could make up their minds.

  10. David & Anthony.
    Selecting a start point is a fact of life. What matters is the basis and reason for selecting the start point and the consideration that you give to the results based on that choice.

    Selecting 1998 as the start point because it’s the only possible way to to get the data to tell the story you want to tell when the greater mass of data paints an entirely different narrative and then declaring that the data does not support global warming (let alone asserting that there is statistically significant cooling) is at best incompetent, at worst deception.

    Selecting a start date because of sound reason with a demonstrable basis in physics or because it is the totality of the data set is not – especially when the conclusions you draw give due consideration (which David fails to do throughout this piece, leading him to a conclusion that is arse about face) to the limits of the data set would represent good analysis.

    Climate at the will, not of physics, but of sine waves? Only on WUWT. – Anthony, can I guest write a piece that demonstrates how the climate data in graph form looks like different mountain ranges?

  11. In my opinion, anything that starts after 1700 is cherry picking…………..

    The LIA taught everyone that we needed heat, a better way to produce food, better ways to cook, harvest……..everything we developed and invented.
    And almost everything that was invented was a direct result of how to take care of ourselves in case it gets cold again………………….

  12. Ric Werme says:
    July 11, 2011 at 5:42 am
    > What happens if I project the polynomial trend-line a few hundred years into the future?

    You torture the data until it tells you what you want. Polynomial fits are generally completely useless for foreward/hindward projections. I tend to look at the end points of the range they cover with a lot of skepticism.

    How many years forward does the fit have to go before the temperature goes below 0 K? What happens if you increase the order of the polynomial by one? One end will show an upward trend – it shouldn’t take much of a projection to get to boiling.

    I know that the polynomial function will go bonkers if I project it to far… I was just too lazy to figure out how to do a Gaussian filter in Excel.

  13. Agree entirely with Ric Werme – never extrapolate from a polynomial fit!

    Anyway, it is always too easy to see patterns in things, and you are better off trying to understand the underlying processes, rather than indulging in curve fitting.

  14. FairPlay says:
    July 11, 2011 at 5:47 am
    So giving the rampant cherry-public often seen here – are you formally saying that cherry picking is inherently wrong?

    If I’m looking for an analogy for my “cherry,” I kind of have to pick another cherry, or at least a cherry-like fruit.

    My point is that “Goldilocks-picking” is “cherry-picking.” If you have a cyclical function, you have to have a sample large enough to see several full cycles – Otherwise, it’s all cherry-picking.

  15. This is my problem with the use of “anomalies”. The definition of an anomaly is “Something that deviates from what is standard, normal, or expected” (http://dictionary.reference.com). Who is the authoritative voice to say what NORMAL is? NASA? Hardly! How about these outfits promote what the ACTUAL temperatures are / were / predicted? I know there are some benefits to calculating anomalies, but as soon as a statistician starts to calculate what is vs. what was expected (starting at point X), then the inevitable argument of cherry picking / Goldilocks picking is guaranteed to ensue. If they want to massage the cr*p out of the numbers to show their (expected) results, then that’s what Steve M and William B have the knowledge and experience to debunk. I just wish that Anomalies weren’t the go-to stat that journalists (hahahahaha I slay me!) like Black could so easily point to, as he screams “Ahhhhhh!!!” like a B-movie actress in a slasher film. Here’s a message for you Blackie: A shill is as a shill does.

  16. FairPlay did you even read the article, didn’t you notice that your AGW belief have lets say some “minor” problems.

  17. this might be nothing, im a computer scientist and did no statistics, but I was using excel…

    I took the GISS data, calculated the mean anomoly for each year (average of each months anomoly), then subtracted each years mean from the previous to get a list of year on year change between each years mean value.
    I didnt do an ABS at any point, I just wanted the change year on year between the means, interested in the magnitutde of change, not the direction.
    I then did a min and a max on it to find the fastest changes between any two years in the data set. I got the same number for min and max 28.58333333 for 1976 to 1977 and -28.58333333.for 1963 to 1964.
    What are the chances of this occuring in a real dataset?

    http://data.giss.nasa.gov/gistemp/tabledata/GLB.Ts+dSST.txt

  18. Jay says:
    July 11, 2011 at 6:48 am

    —————————————-

    But, the only people who selected starting points are Kaufmann et al and Richard Black.

  19. Ok then the AGW folks have their answer to controlling the climate and it is already pretty much in place. Crank up the coal-fired power plants with high-sulphur coal and turn the scrubbers on and off as needed to regulate the temperature. The bonus is that we get more CO2 which is needed to increase crop yields to feed the growing world population. Two problems solved at no cost to you. In addition you get lower cost electricity and less government involvement as a bonus. What’s wrong with that?

  20. Ok, let’s try this running average thingee on the data from some hypothetical world.
    1 1 1 1 1 1 1 1 1 1 3 2 2 2 2 2 2 2 2 2 2 2 2. Assuming these are the readings from some annual temperature series with the 3 reading being 1998 what do we get? In 1997 we have 1 as our running average. In 1998 it jumps to about 1.2 and then rises gradually to 2.1 by 2007 and then drops to 2.0 an then stays the same. Anyone seeing this series would immediately say the temperature has remained constant for the past decade. Arguing that actually the temperature has risen is just playing mind games. This is essentially what this article is claiming.

  21. If Warmista Gaia Models are to be treated as scientific hypotheses then what we know about them is that since 1998 their predictions have been false. Rather than recognize that the models contain one or more false hypotheses, the Gaia Modelers introduced a new hypothesis, Chinese aerosols, to save their Gaia model from falsification. However, the tactic did not work because now the modelers must face the criticism that their Gaia models did not account for aerosols. The Gaia models were either false to experience or incomplete. In either case, the Gaia models are not up the standards of science.

    If Gaia models are not to be treated as scientific hypotheses then they must be treated as statistical hypotheses about two sets of numbers, a temperature reading and a CO2 reading. Here we encounter all the problems of the famous Hockey Stick. As The Team learned when they decided to “hide the decline,” for the statistical comparison to be meaningful, you must know enough about the things compared to be able to explain why they are worthy of comparison. So, what do the Warmista do? They bring in aerosols to save their statistical hypotheses about CO2 and temperature. There can be no successful account of CO2, aerosols, and temperature until there is a scientific account of each, given in terms of physical hypotheses that describe natural processes, that enables the researchers to explain that the objects of their study, CO2 concentration, aerosol uptake, temperature records and such are not changing. They have no such accounts and are not seeking to create them. The Gaia Models are no more nor less than Hockey Sticks.

  22. I think you give to much credit to Mr Black he’s more of a sycophant, “Yes emperor Gore your new kings cloths look amazing”.

    While the sane people sit in the pub opposite pointing and laughing at a naked jester.

  23. Jay says:
    July 11, 2011 at 6:48 am
    David & Anthony.
    Selecting a start point is a fact of life. What matters is the basis and reason for selecting the start point and the consideration that you give to the results based on that choice.

    [...]

    The reason Mr. Black picked 1880 starting point is that it is the beginning of the instrumental record. The entire instrumental record is within the warming leg of one cycle millennial-scale climate oscillation. It’s been warming on that millennial since ca.1600 AD.

    If you look very closely at the GISP2 core, you’ll find that the millennial scale cycle had a period of ~1,470 (+/150 yrs) years during the Pleistocene. Many people call this the Dansgaard-Oeschger cycle. This cycle appears to have sped up in the Holocene (~800-yr period +/-300 yrs). If you look at Moberg et. al., 2005, Ljungqvist, 2009 or even Mann et al., 2008, you can see that the last 2-3 cycles of this oscillation have had periods of ~1,000 years… Alternating 400-500 year periods of warming and cooling.

    Embedded on that millennial-scale cycle is a multi-decadal or century-scale oscillation with a period of ~60 years. The most recent warming leg of that ~60-yr oscillation ran from ca 1976 to ca 2003. 1998 just happened to be a monster El Nino near the peak of both the millennial and multi-decadal oscillations. This is why it is the warmest year “on record” everywhere outside of NASA & NOAA. The reason for picking 1998 as a starting point is the fact that it is the warmest year “on record.” Personally, I think 2003 would be a more relevant “cherry” from which to start, if the goal is to look at the current cooling leg of the multi-decadal cycle.

    The use of a Sine wave was simply as an analogy .

  24. Ric Werme says:
    July 11, 2011 at 5:42 am
    > What happens if I project the polynomial trend-line a few hundred years into the future?
    You torture the data until it tells you what you want. Polynomial fits are generally completely useless for foreward/hindward projections.

    =====

    Exactly. The problem of dubious polynomial behavior at and outside the data boundaries seems to be fairly well known, but it lacks a name the one can feed into a search engine to find analyses of the problem. The problem can be exacerbated by fitting to too HIGH a degree of polynomial because each additional degree in the polynomial adds an inflection point to the curve. Inflection points near the boundaries are bad news as they allow a handful of data points to send the projected values outside the data to soar/crash toward plus or minus infinity at rates that aren’t remotely appropriate.

    IMHO, If you are fond of correct answers, extrapolating linear fits can cause you more than enough grief. Polynomials are unlikely to be helpful.

  25. My biggest issue with the “Temperature anomaly” and cherry picking start and end dates is that, in order to prove CO2 is going to kill us all, some scientists picked a 30 year time period and called it “normal.” They then show any deviation from the average temperature at during that time period as an anomaly. If they are going to pick a normal temperature of the Earth, they should take the average temp from the last few million years, and express that temperature in Kelvin. Then, using the known deviations from that temperature as natural variability, plus or minus, the project out standard deviations. If we are not three standard deviations from the norm, we are still within the range of natural variation and there is no reason to look for any cause.

    I could be wrong, but I believe our normal temperature is somewhere in the range of 283 degrees Kelvin, and the normal deviation is around 2.5 degrees. That would put 3 standard deviations at around 300 degrees Kelvin, right? So, unless we cross that line, we should be right where we are supposed to be, right? Isn’t that how it works?

    Please correct my numbers if I’m wrong.

  26. Reflected short-wave solar radiation has not increased since 1984, it has probably gone down slightly (according to the Ceres and Erbe satellites)

    So the Asian aerosol explanation does not work. We know the Asian aerosols have gone up, but for the Earth as a whole, there is very, very little change in the reflected solar radiation (just a blip from Mount Pinatubo in 1991-1993).

  27. nicola scafetta says:
    July 11, 2011 at 6:39 am
    The climate system is clearly characterized by a 60-year cycle.

    Climate is defined as weather averaged over 30 years. This greatly magnifies the calculated change in climate when there is a 60 year cycle.

    As a result, the past fears over global cooling and now over global warming. Had science chosen 60 years average for climate, there would have been no alarm over global cooling of global warming, because the average would not have changed significantly.

    The simple fact that the trend changes significance levels when you change the length of the moving average, this shows what you are dealing with is not real. It is a mathematical artifact. This has been formally recognized by Japanese researchers and is a large part of the reason they announced they would withdraw from Kyoto.

    Climate change disappears when you change the definition of climate from weather averaged over 30 years to weather averaged over 60 years. It is an artifact of the definition, not of the climate system. When you change the definition of climate to 60 years of weather there is no significant warming post 1950 as compared to the warming since the end of the LIA.

  28. All of this will be over by 2015, when the records of 2010 and 1998 will have been obliterated by increased solar activity, ENSO and decreased albedo as we go into virtually ice free arctic summers, oh and increased GHG concentrations of course. Then we can pick another year as the peak of the cycle start drawing lines to any next cooler year to prove the earth is not warming.
    Anthony, if you are so opposed to cherry-picking, why don’t you mention all the other recent peer-reviewed reconstructions of past temperatures? I’m sure they all show the same nice cyclical pattern.

  29. nicola scafetta says:
    July 11, 2011 at 6:39 am
    As extensively proven in my paper
    N. Scafetta, “Empirical evidence for a celestial origin of the climate oscillations and its implications”.

    I have strong reservations about your above claim. I have not found any evidence of the 60 year cycle within the climate indices. ‘Planetary connection’ is not obvious with its physical mechanism or its presence in the available data.
    Solar correlation also appear to be very tenuous, at least as far as the longest temperature record is concerned

    http://www.vukcevic.talktalk.net/CET-SSN.htm

    However there is a good correlation with the oceans’ currents distribution in both the North Atlantic

    http://www.vukcevic.talktalk.net/CET-NAP.htm

    and the Pacific ocean.

    http://www.vukcevic.talktalk.net/A&P.htm

  30. @Don K (July 11, 2011 at 7:24 am)

    I wasn’t making a “prediction” with the extrapolation of the polynomial function. The purpose was to demonstrate the cyclicity that is painfully obvious over the last 2,000 years and to schematically demonstrate how that pattern should continue over the next few hundred years.

  31. Grizzled Bear says:
    July 11, 2011 at 6:58 am
    “This is my problem with the use of “anomalies”. The definition of an anomaly is “Something that deviates from what is standard, normal, or expected” (http://dictionary.reference.com). Who is the authoritative voice to say what NORMAL is? NASA? Hardly!”

    As much as I hate to sound like a broken record, I must state my agreement with Grizzled Bear. The fact that anomalies are being used instead of actual empirical observations means that some assumptions have been made. Never have I seen these assumptions clearly explicated and defended. Other branches of physical science do not proceed in this manner.

    The one defense of anomalies that sometimes gets stated is that the actual temperature readings are all over the map because they vary with altitude and many other factors. To my mind, there is no clearer case for not using anomalies. The fact that your science cannot do justice to your actual empirical observations should tell you that you are not doing science.

  32. Here’s a question. What happens to the charts and trends if we use the same sensitivity as when we first started recording temp data? ( i.e. we can now read to the thousandths of degree( 0.000))

  33. Polynomial fits of degree n are useless if there is no underlying physics to make a polynomial of degree n relevant.

    With enough terms you can fit any data, but without physical basis or insight. For example fitting a falling body accelerating with gravity with a quadratic fit makes sense. Fitting the earth’s temperate with a 5th order polynomial is fantasy.

    A cyclic fit based on a sine wave of combinations of sine waves could make sense of there are cyclic phenomena going on( as is the fact, orbits etc).

  34. @FairPlay
    July 11, 2011 at 5:47 am

    “So giving the rampant cherry-public often seen here – are you formally saying that cherry picking is inherently wrong?”

    I can’t speak for David Middleton, but I can say that in my opinion, in the case of CAGW proponents, yes, it is. In the case of those that are skeptical of the CAGW hypothesis, no, it isn’t. In fact, it cannot really be defined as ‘cherry picking’, much as alarmists need to believe that in order to sleep at night.

    To elaborate, I’m guessing you would make the same assertion as the IPCC – something along the lines of: ‘the rise in global average temperature since the start of the 20th century is overwhelmingly due to anthropogenic CO2 emissions, to a degree that eclipses natural variation’ or suchlike.

    In order to have any credibility however, this assertion needs to be supported by evidence that:

    (a) only CO2 + water vapour feedback effects can account for the majority of this rise (and that it can be separated from noise and natural processes like ENSO, PDO, cloud cover etc);

    (b) this rise in global average temperature is unprecedented in history, in that nothing other than CO2 emissions can explain it;

    (c) there is unanimous reliable evidence between corresponding data sets that temperatures have risen at the rate, and to the degree that would be required of the original assertion.

    The problem for CAGW proponents is that this evidence is very thin on the ground, if not entirely missing. In order to ‘prove’ (a), evidence has to be fabricated – literally – in the sense of using computer simulations with a preordained bias towards the hypothesis (see Judith Curry’s series of articles: ‘Overconfidence in IPCC’s detection and attribution’, which discusses ‘bootstrapped plausibility’ of models). To date, no climate model has been shown to have any predictive ability, and they are all pretty weak in hind-casting too (and that’s the easy part – you can just rejig forcing parameters to fit the model to historical trends, and claim any correlation as victory).

    The only way to prove (b) is to carefully ‘cherry pick’ start and end points of your analysis (usually different ones in different datasets, depending on how badly your argument fares), as outlined in David Middleton’s article above.

    (c) cannot even be demonstrated at all by CAGW enthusiasts, so they tend to ignore it, or claim some deficiency in any record that doesn’t support their agenda. The paleo record does not agree with the instrumental record, satellite observations do not completely agree with the surface record, surface records do not completely agree with each other, and none of the records agree with the model projections.

    So, cherry picking and fabrication is needed to demonstrate CAGW. When temperature records are seen in their historical context (as above), the CAGW hypothesis is unprovable. The fact that cherry picking is required at all to make a case makes this self-evident.

    However, having the ability to find, select and present evidence that weakens or counters the CAGW hypothesis does not weaken the counter argument. For example, I can legitimately claim that the CAGW hypothesis is invalidated by the fact that none of the datasets since 1998 show significant warming. Even if you quibble about the meaning of the term ‘significant’, the fact that none of the datasets have risen to the levels predicted by past climate models – even in their ‘best case scenarios’ for CO2 emissions – still blows the hypothesis out of the water. There is no correlation between CO2 levels and temperature. Even one ‘cherry picked’ argument like this severely dents the CAGW hypothesis, and there are many more. The fact that there might have been a correlation between rising CO2 levels and temperatures between 1980 and 1995 has absolutely no bearing on my claim, and does not invalidate it in the slightest. It just leaves the door open for something other than CO2 being responsible for temperature rises in this period. So the cherry I have picked is valid.

    As a CAGW proponent, the only avenue left to support your hypothesis beyond the illegitimate form of cherry picking I have highlighted is to attempt to reverse the burden of proof, and failing that engage in meaningless hand-waving, hoping nobody will call you out on it. For examples of the latter: ‘It must be particulate emissions from China countering global warming since 1998.’ Where are your measurements? What happened to all the Western industrial soot during the rest of the industrial era? ‘The Greenland ice cores only show regional, not global temperatures.’ Then why do you rely on GISS – where the only warming ‘signal’ comes from a small number of stations susceptible to large temperature variations due to changing coastal sea-ice, and is statistically extrapolated across vast swathes of the arctic – to demonstrate ‘global warming’ beyond that measured by satellites. My counter arguments are no less valid for having been cherry-picked.

    Reversing the burden of proof, as suggested by Trenberth, as an alternative to AGW cherry picking, is just semantic nonsense used to wriggle out of having to provide justification for AGW assertions. However, even if sceptics do indulge AGW proponents and allow this, no problem. I hypothesise that natural variations can account for the vast majority of the warming seen within the bounds of certainty in the surface and sea temperature records in the industrial era. Just browse this blog for ample evidence of this: Bob Tisdale’s articles on ENSO, Mr Watts’ posts on Urban Heat Island effect on surface temperature sensors, posts such as the one above demonstrating distinct lack of ‘unprecedented’ in temperature rises, Willis Eschenbach’s posts on thunderstorms and tropical convection ignored by climate models, Svensmark and cloud cover, passing of energy over decadal cycles through changing ocean currents ruled by bounded chaos, observational evidence of feedback effects etc. Prove, beyond a doubt, any and all of these natural factors incapable of causing the warming we have seen and I will give you a huge cherry.

  35. David Middleton says:
    July 11, 2011 at 8:05 am

    “I wasn’t making a “prediction” with the extrapolation of the polynomial function.”

    =====

    I’m not trying to give you a hard time, but it’s hard to see how you aren’t making a prediction even if you aren’t framing it in the “usual” “climate science” sense of trying to demonstrate that we are all doomed unless we repent our sinning ways right now, today.

    If you are trying to demonstrate cyclicity, wouldn’t Fourier analysis do that more cleanly? And no, before you ask, I don’t have the slightest idea how to do a rigorous Fourier analysis in Excel. Here’s a link that purports to explain how to do something along that line. http://www.brainmapping.org/NITP/PNA/tests/ProblemSet3_files/FourierExcel.htm

  36. Grizzled Bear says: “This is my problem with the use of “anomalies”. The definition of an anomaly is “Something that deviates from what is standard, normal, or expected” (http://dictionary.reference.com). Who is the authoritative voice to say what NORMAL is? NASA?…”

    Grizzled Bear, the choice of the base years for anomalies makes no difference to the trend of the data or to the year-to-year variations. Changing the base years only shifts the entire dataset up or down. If you used 1880 to 1909 as the base years for a global temperature anomaly graph, most of the data would be above zero. Likewise, if you were to use 1980 to 2009 as the base years, most of the early data would be below zero, but the curves are the same.

  37. The extreme AGW cherry picking is also to ignore the paleoclimatic data and the cosmogenic isotope changes that correlate with the paleoclimatic data,

    The interglacial and the glacial planetary temperature data shows cycles of warming and cooling interrupted by very strong “RCEs” (Rickies) Rapid Climatic Change Events (For example the Younger Dryas abrupt cooling event and the termination of the last interglacial).

    There is smoking gun evidence (cosmogenic isotope changes BE10 and C14) shows there are cyclic changes to the sun and abrupt changes to the sun and that the solar change occur at every climate change event. The question is not if but how the solar serial climate changer causes the cyclic gradual (mediavel warm period and the little ice age) and abrupt climate change (abrupt termination of the last 22 interglacial periods. There are clearly multiple mechanisms by which the sun changes the planet’s climate. (i.e. Abrupt and gradual climate changes are not caused by simple TSI changes. The sun does not get warmer or cooler to cause the observed climate change.)

    The sun was at its highest activity state in 10,000 years during the later half of the 20th century. The solar magnetic cycle has been abruptly interrupted.

    The AGW extremists are one trick ponies. The clear and present climate change danger is gradual and abrupt cooling.

    I am curious what the AGW propaganda response will be a to cooling planet.

  38. So the Chinese have fixed the global warming problem then …… without even really trying ??

    That makes our lot look doubly stupid, eh ? Wind turbines destroying the environment etc.

    Sulfur (sulphur) tax coming if it gets any colder ??

  39. nicola scafetta says:
    July 11, 2011 at 6:39 am

    “The climate system is clearly characterized by a 60-year cycle. We have seen statistically compatible periods of cooling during 1880-1910, 1940-1970, 2000-(2030 ?) and warming during 1850-1880, 1910-1940, 1970-2000.”

    Yep. We determined that in the course of the thread discussion here. I produced a PSD of HADCRUT data here which clearly shows a peak at ~65 years for the 20th century.

    The physical basis for this cycle is that it is the result of excitation of a lightly damped mode in the Earth’s climate system driven by random inputs, not a steady state sinusoid. Over limited duration intervals, it can appear as a quasi-periodic, quasi-steady state sinusoid, but over longer intervals, the period appears to wander somewhat and the waverform appears to be amplitude modulated. This is a normal and completely ordinary phenomenology exhibited by systems governed by partial differential equations.

    Engineers use finite element analysis to predict oscillatory modes in structures and fluid and electrical systems and so forth every hour of every day of the year, and use that knowledge to design buildings which will withstand gale force winds, or pumps which will deliver water to widespread communities, or substations which provide their electrical power. It’s old hat. Basic. Elementary. Cut and dried. Yet, the climate science community denies the existence of system modes. As I have related to many over the past decade or so, the climate scientists are trying to reinvent the wheel, and doing it very badly. Right now, their best model is a square.

    Note, too, that the entire AGW imbroglio is founded on ~30 year trending, i.e., the interval you would need to either maximize or minimize the estimation of a trend. A ~30 year period is also roughly the rate of generational turnover, and loss of institutional memory, in human affairs. And so, we have had alternating Global Warming and Global Cooling scares like clockwork for the entire past century.

    We have just reached the peak of the ~60 year cycle, which is why temperatures have stabilized. Soon, they will be trending down (superimposed on the long term rise from the last ice age), and all the sturm und drang of last couple of decades will be cast down the memory hole. Anyway, Nicola, good to see others are aware of what is really going on.

  40. I know the areosol cherry pickers are wrong and just goes to show how little they really know or really hide. Why wasn’t declining areosols over the decades by the same people mentioned to be part of warming? It wasn’t because these are the best cherry picking hockey stickers in science.

    The pause in warming has not been accounted for by increases in SO2 emissions. The recent conjecture trying to expain this, shown no observed science to back this up, other than the fact emissions in the troposphere had increased recently in a few countries including India and especially China. Whereas especially the USA and Europe, SO2 levels have declined over the decades. The major problem here is that SO2 behaves differently when in the troposphere compared with the stratosphere. There is no observed evidence showing that human SO2 emissions reach the stratosphere. In the troposphere it has a very short life and interacts with water vapour creating acid rain. The SO2 that manages to briefly survive this has been demonstrated to show a warming. SO2 that reaches the stratosphere behaves differently and contributes to cooling. This is described in more detail via the link below.

    http://www.tetontectonics.org/Climate.html

    There are numerous volcanic eruptions that release SO2 into the troposphere each year and have no noticeable affect on global temperatures, where cooling at least is concerned. Only the major volcanic eruptions that reach the stratosphere that affect global temperatures with cooling and how much depends on the lattitude of the planet. Pinatubo in 1991 emitted 15 times the amount then any maximum background stratopheric aerosol opitcal thickness during the recent decades. this contributed 0.35c in cooling over a few years. The background at any one time only contributed 0.02c and this value is far two small to explain the cooling between the 1940’s and 1970’s plus the pausing of recent decade global temperatures. The change in the ENSO, PDO and AMO explains this cooling much better.

    http://data.giss.nasa.gov/modelforce/strataer//

    The global stratospheric aerosol optical thickness shown above has declined over the recent decade. Thus it is not contributing to the recent pause because it requires to have increased for this to have any scientific weight.

    If the CO2 had high sensitivity then any warming suppose to have occurred would have already happened by now. If CO2 has low sensitivity than it has contributed very little towards global warming because virtually all of the rise has occurred in just a few short steps. The observed planet shows it is currently the latter because the steps have only occurred exactly at the same time of a strongish El Nino.

  41. The BBC, with so much “invested” in the scam, are we surprised? What really concerns me is the num ber of people who fall for this, hook line and sinker. No-one actually goes to a library anymore, just lap up the BS from the MSM. Monkey see, monkey do!

  42. The only statistics that matter are the concentration of CO2 in the atmosphere and average global temperatures. Remember, the Warmist argument that underpins their stance, and the reason they feel justified in proposing draconian measures to reduce CO2 output, is that the influence of CO2 over-rides all other factors in atmospheric thermodynamics. Lets not allow the AGW brigade to deflect the debate away from the fact that this magical correlation does not exist. It doesn’t matter what sophistry they come up with, the fact that the temp does not closely follow CO2 concentration (even allowing for time lag) blows their own argument out of the water.

  43. Don K says:
    July 11, 2011 at 9:19 am
    David Middleton says:
    July 11, 2011 at 8:05 am

    “I wasn’t making a “prediction” with the extrapolation of the polynomial function.”

    =====

    I’m not trying to give you a hard time, but it’s hard to see how you aren’t making a prediction even if you aren’t framing it in the “usual” “climate science” sense of trying to demonstrate that we are all doomed unless we repent our sinning ways right now, today.

    If you are trying to demonstrate cyclicity, wouldn’t Fourier analysis do that more cleanly? And no, before you ask, I don’t have the slightest idea how to do a rigorous Fourier analysis in Excel. Here’s a link that purports to explain how to do something along that line. http://www.brainmapping.org/NITP/PNA/tests/ProblemSet3_files/FourierExcel.htm

    Don,

    It’s perfectly OK to give me a hard time… I shouldn’t be using polynomial functions as a lazy way to simulate a low-pass filter. But DifEq was a long time ago and I forgot everything I once knew about doing Fourier transforms a long time before I learned how to use Excel & blog… ;)

    Learning how to properly do Fourier transforms, Gaussian filters, power spectra, etc. is on my hobby time “to do list.”

  44. JJB MKI says:
    July 11, 2011 at 9:12 am

    You have written a brilliant essay, Sir. You have placed the ball squarely in the Warmista court. Your valuable time has not gone to waste; to the contrary, every critic of the Warmista position should print your post and tape it to the monitor.

    About that ball in the Warmista court. They will have to fire up some Gaia Models and average them before they can respond.

  45. These cyclic temperature trends give rise to an inevitable linkage to things we know for sure: Death and Taxes. As governments get sufficiently sophisticated, they will (or have) formulated ways of applying taxes to normal, cyclical climate fluctuations–they’ll tax us for making the temperature go up, and once that’s over, they’ll figure out how to tax us for making the temperature go down. Such governments are corrupt entities, of course, since they don’t deal with the truth–they just use natural phenomena to scam their citizens.

  46. Steve Jones says:
    July 11, 2011 at 10:18 am

    Absolutely! Keep the focus on the relationship between the CO2 concentration and the temperature because that relationship is the heart of the Warmista position.

    If Gaia Models are hypotheses then they have been falsified. If they are statistical claims about correlations between two sets of numbers, CO2 concentration and temperature, then there is no correlation.

    If they are statistical claims based on Bayesian Priors then they are fantasies just as the Priors are fantasies.

  47. David in Georiga says:
    July 11, 2011 at 7:44 am

    My biggest issue with the “Temperature anomaly” and cherry picking start and end dates is that, in order to prove CO2 is going to kill us all, some scientists picked a 30 year time period and called it “normal.” They then show any deviation from the average temperature at during that time period as an anomaly. If they are going to pick a normal temperature of the Earth, they should take the average temp from the last few million years, and express that temperature in Kelvin.

    Fair enough, but even a 60-yr time period would be an enormous improvement, particularly since there is much evidence that that pretty closely matches the period of observably cycles. You;d get both phases of the ‘wave’. As an exercise, try a super-simple model that predicts that weather and climate for the next few years will match that of the early ’50s.

  48. This is blatant headline cherry-picking and obfuscation. The paper is about decreased carbon capacity in the ocean. The paper WAS NOT about determining exactly what the absorption limit of the ocean is.

  49. I find it rather interesting that within an hour or so of this posting here, Richard Black posted a new article on his BBC blog, pushing the subject of this one off the front of the BBC’s Science/Environment page.

  50. @ David Middleton July 11, 2011 at 7:24 am

    Thank you for both your article and especially for the above post.

    I have read over the past about the multi-decadal and millennial oscillations and supporting evidence. In filtering through all involved in the CAWG scam I have been trying to put a summary of where the two oscillations come together. Your post as noted above was what I was looking for.

    With an engineering background, it probably took me over a 1,000 hours research to get a firm grasp on what was going with the CAWG issue. I’ve probably logged over 4,000 hours now. That house of cards is in total collapse now. Due to over 30 years in building such a scam it took a while to expose its foundation. Keep up the good work as it’s a complex issue and takes a lot of reading to get a grasp of what has transpired. I would guess that many with the ability to understand are now seeing the light, so to speak. The less knowledgeable will likely continue to be more religiously afflicted as it will be difficult if not impossible for them to understand the degree of involvement in this scam. Few politicians have the technical knowledge to understand anything near the complexity of this issue. They will likely just follow the public sentiment with hopes to be re-elected, many will not be.

    Again, I want to thank you as well as the many others who are the watchdogs of science and policy. With over 82,000,000 hits on his blog I don’t have to mention Anthony, but thanks anyway!

  51. “oglidewell says:
    July 11, 2011 at 10:50 am”

    Out of sight, out of mind mentality. Similar to that 10 second sound bite pollies rely on and our “youth” seem to soak it up like crusty bread in a stew. Strewth if ever a “carbon tax” app is developed for “smart phones” (LMAO), these suckers will lose $’s so fast they won’t know what is happening. Oh hang on, iTunes, SATNAV and Google Maps, via ISPs, are doing that right now! LOL.

    This “disappering” of stuff also happens all too frequently at the Australian SMH website, especially when posts seem to be in disagreement with the authors’ PoV.

    We can only thank Al Gore for inventing the inter-webby thing. Thanks Al “50% man, 50% bear, 50% pig” Gore.

  52. M.A.Vukcevic says:
    “I have strong reservations about your above claim. I have not found any evidence of the 60 year cycle within the climate indices. ”

    Dear Vukcevic,
    a quasi 60-year cycle in the climate has been observed by a lot of people in a lot of climate records some of them covering centuries and millennia. In addition to the clear results from my paper where 10 records are explicitly studied, you need to look at the numerous references that I add there.

    Just two papers dealing with the issue where several multisecular and millennial records are studied and found 60-year cycles lasting for millennia are:

    Cyclic changes of climate and major commercial stocks of the Barents Sea

    http://www.tandfonline.com/doi/abs/10.1080/17451000802512283

    see for example figure 4 and table 1

    and
    Tracking the Atlantic Multidecadal Oscillation through the last 8,000 years

    http://www.nature.com/ncomms/journal/v2/n2/full/ncomms1186.html

    see for example figure 5d

    (Of course, when I say that a 60-year cycle exists in the climate system, I am not saying that the climate system contains “only” a 60-year cycle. There are other cycles longer and shorter. Nor I am claiming that this 60 year cycle is “perfectly” sinusoidal: I am talking about physics of complex non-linear chaotic systems, not trigonometry.)

  53. Climate Majority says:
    July 11, 2011 at 10:49 am
    This is blatant headline cherry-picking and obfuscation. The paper is about decreased carbon capacity in the ocean. The paper WAS NOT about determining exactly what the absorption limit of the ocean is.

    I think you meant to comment on a different post.

  54. If this is really happening (see link below) Gillard does not have a chance in hell in getting this tax through.

    http://www.couriermail.com.au/news/national/cast-your-vote-in-national-plebiscite-on-carbon-tax-hosted-by-news-ltd-websites/story-e6freooo-1226091387866

    It seems that exposure to this tax has made people read up on the science and 60% don’t believe in it any more and now 80% are against it. I suspect the survey may be biased but if anywhere close there appears to be a massive shift going on just now in the Australian Psyche. Thanks to the insistence of the greenies and warmistas on getting this through despite massive opposition. I predict a complete collapse of the whole Carbon Tax within a week or two

  55. @JJB MKI says:
    July 11, 2011 at 9:12 am

    I would second Theo Goodwin’s applause of your post. Well said.

  56. Nicola Scafetta said:
    “The climate system is clearly characterized by a 60-year cycle. We have seen statistically compatible periods of cooling during 1880-1910, 1940-1970, 2000-(2030 ?) and warming during 1850-1880, 1910-1940, 1970-2000.”
    Great!
    Quoted and linked from “Climate Change (“Global Warming”?) The cyclic nature of Earth’s climate “, at http://www.oarval.org/ClimateChange.htm
    Thanks!

  57. Nicely presented and all very true, everyone picks their trend to make their case, however, there is one big difference, everyday, all across the planet, scientists are conducting research to find the reasons behind climate dynamics. They are measuring a myriad of things and finding that these trends and cycles are not random walks– but have actual causes. There are real reasons behind every major climate change, from major changes like the coming and going of glacial and interglacial periods to relatively minor changes like the so-called “Little Ice Age.” All these things have causes, and for some of the warming that has occurred in the later part of the 20th and into the 21st century, when all other known factors are excluded, including solar cycles, (yes, solar cycles have long been known to affect temperatures) the only known factor that remains is the anthropogenic fingerprint of greenhouse gas increases.
    Might there be some other, as yet unidentfied, cause? Absolutely! And if there is, it is only through the hard work of climate research that it will be discovered and quantified.

  58. “Erik Styles says:
    July 11, 2011 at 11:22 am”

    I remind you of Thatcher (UK) and Clark (NZ) and men before them. Under Gillard, in Aus, there will be a carbon tax, and The Greens and Labor will commit political suicide along with it, but it will take a while for the Aussie public, sleeping and driving at the wheel, to wake up. Fu&% me, I hope it is soon! At least KRudd747 knew if “labor” wanted to stay in power…an ETS was not the way to go (Sorry bankers) without support from Japan, India, China, and the USA…well, Gillard has no clue, she will not fail, politically, in implementing the “proice on cahbon”. Trouble is, in Aus, we have the likes of Abbott and Turnbull, Turnbull being an ex-(w)banker…and knows what this “pollution” tax really means. Its the biggest ponzi scheme evah!

  59. Bob Tisdale says:
    …the choice of the base years for anomalies makes no difference to the trend of the data or to the year-to-year variations. Changing the base years only shifts the entire dataset up or down.

    But Bob, that’s my point. The selective individual can make the anomaly data look like anything they want it to, by starting wherever the data gives them their most sensationalist narrative. And when you start adding an artificial cut-off date, as some are wont to do… well, now we really enter into the Wonderland made famous by Alice (pardon me for mixing my fictional metaphors). When hard-hitting top-notch investigative journalists like Richard Black (cough! Excuse me while I choke up a hairball!!) get hold of this stuff, he spins a yarn better than the girl trapped in the tower in Rumpelstiltskin (sorry, couldn’t resist again!). “Now kiddies, lie back and close your eyes and suspend all rational thought while Uncle Richie concocts a tale guaranteed to scare the pi** out of you.” Remember that, while you might be extremely scientifically articulate, the average reader of Black’s literary genius probably isn’t. Black knows this and, in fact, counts on it. That’s why he’s always spinning like a Republican at a Democratic convention (or visa versa, if your politics prefers). When Phil Jones said that there hadn’t been any statistically significant warming since 1998, and that news got trumpeted at the tops of our lungs, journalists like Black (who, after all, are only looking to report the TRUTH, aren’t they?) had to find a way to get the narrative back on track. “So… let’s see…if we calculate a 10-year rolling average anomaly for each of the last 10 years, and show that most of them have gone up each time…well lookie what we have here. Let those damned deniers try to get out of this one.” And the reaction of the Stepford wives reading his column is to believe, believe, believe. Have you ever tried to explain a temperature anomaly to a guy while he’s standing over the grill sucking on a brew? It’s just so much easier to believe what the nice man wrote in the newspaper. I didn’t really understand it, but after all, if it’s in the paper then it has to be true. Doesn’t it?

  60. oglidewell says:
    July 11, 2011 at 10:50 am

    “I find it rather interesting that within an hour or so of this posting here, Richard Black posted a new article on his BBC blog, pushing the subject of this one off the front of the BBC’s Science/Environment page.”

    Yes, and replaced with a ‘filler’ article. In the meantime, and for some time now, the comments on Black’s blog have been becoming increasingly skeptical and mocking which is why the BBC has decided to reduce them to mega-tweet size.

    Enjoyed your comments there by the way. But rather than take your advice and read this post I expect Black will keep his head firmly in the AGW sand or just cover his ears and keep screaming that the debate is over. After reading that blog for several years I’ve concluded that Black is a very simple parrot.

  61. nicola scafetta says:
    July 11, 2011 at 11:13 am

    “Of course, when I say that a 60-year cycle exists in the climate system, I am not saying that the climate system contains “only” a 60-year cycle. There are other cycles longer and shorter. “

    They’re not all really cycles, as in deterministic sinusoidal oscillations at a particular frequency. There are such cycles, as governed by diurnal and seasonal and Milankovitch forcings. But, there are also quasi-cyclic phenomena which reflect the response of narrowband system modes to random forcing. The distinction is important because, the first argument you will get against the idea is that there is no known forcing with a ~60 year period.

    But, all systems governed by partial differential equations with limited rates of energy dissipation exhibit particular modes of oscillation which can be excited by random inputs of no particular coherence. These modes are determined by the physical properties of the system and its boundary conditions. In the simplest idealization, for example, a linear spring with spring constant K attached to a perfectly rigid support at one end and a point mass M on the other will oscillate at a radial frequency sqrt(K/M), or a pendulum of length L in a constant gravity field with acceleration g will oscillate about the equilibrium at a frequency of sqrt(g/L).

    A particularly notorious example of a system oscillating at its natural frequency due to random forcing, to the point of catastrophic failure, is the Tacoma Narrows Bridge.

  62. It’s really one of those ‘miracles’ of Science that the decrease in temps from aerosols emanating from power plants has almost exactly balanced out the increase in temps from increasing CO2 for a period of 20 years as BOTH sources increase/change at different rates.

    One would think that, if this hypothesis were true, and if the rate of increase of aerosols is greater than the rate of increase in CO2 (which appears to be the case), and if aerosols do tend to cool, that there would have been net cooling over the 20 year period instead of a net plateau in temp increases.

  63. In the end this comes down to the fact that reality has failed to support the models , and although in climate science that means reality is wrong . In the real world for real people the failure of temperatures to match to ‘doom serous’ pushed out by the CRU etc is real problem for Black and Co and so there is very much a need to explain the problem away . Step forward another model and speculation its ‘ aerosols’ that is keeping the temperatures rises of ‘doom’ at bay .

  64. Bart says:
    July 11, 2011 at 1:15 pm
    …..
    It is easy to be mislead by the quasi-cyclical appearance within some of the climate related data. Most of the ‘identified’ cycles are very little to do with celestial events, and far more to do with ocean currents and Coriolis force. Detailed map of the ocean currents

    shows number of gyres (circular currents). All of these take certain number of years to complete a full cycle, leaving individual imprint on the climate data (either global or a hemisphere’s), with number of sub harmonics with cross-modulation products, combination of which may leave impression of existence of a unique forcing factor.
    These range from few years (Beaufort gyre 4 years, Circumpolar current 8 years, Indian ocean gyre 10 years, N. Atlantic subpolar gyre 20 years etc.) up to above 100 years for some of the Pacific gyres, and finally the great ocean conveyor belt estimated at ~1600 years.

  65. Might I point out that a linear fit is simply a first-order polynomial fit?

    And *lots* of people use linear fits without blushing.

  66. R. Gates says:
    July 11, 2011 at 12:01 pm

    More pseudo-intellectual, worthless and wholly incorrect pontification/claptrap from our resident non-scientist.

    Is this you ?

  67. Warning!! Scientific over-achievers may find this boring, imprecise or both.
    Regular folks may want to skip to the last paragraph, immediately, or when you get saturated.
    Conclusions may be classified somewhere between “educated Scientific guess” and “Wild eyed speculation”.

    As an introduction, Many WUWT contributors and commentors forget (or ignore) that most of us followers of that blog have less than 60 college hours in Science classes. While I have more, the grades were almost all “C’s” except for one Physics, one Chemistry, one Botany and two Geology classes. (These were “A’s”… also got an A in “Physics for Elementary Teachers” but that hardly counts) The following is aimed at making sense of entries by the scientific over-achievers here.

    Sometime in the ’90’s some college students were examining spectral lines (Bright lines made by glowing chemicals, when the light from those chemicals are passed through a prism… chemicals on the sun’s surface tend to glow) from sunspots on the sun. A followup study revealed that some of these lines were getting dimmer. This lead to a serious study of those spectral lines. The study showed these lines were indeed diminishing. A forward projection of the rate of decline showed these spectral lines indicated they would be entirely gone by 2015 or so. Then came the bad news. Further study showed when these spectral lines were bright the solar activity was high. When they were dim the solar activity was low. or simply: Bright lines hot sun, dim lines cooler sun. Science based speculation extends this evidence to guesstimate that a repeat in the “Little Ice Age” is upon us.

    The sun directs about 1,350 watts of visible light to the earth surface (per square yard/meter per second of time) when directly overhead. As the earth is nearly a sphere, time of day and latitude (Distance away from the tropics) diminish this number. That is slightly less energy than you get from an 1500 watt electric heater. In the northern hemisphere, the difference in solar energy between summer and winter averages about 150 watts per second or so (again depending on time and latitude). The difference between hotter and cooler sun is two or three watts per second. {{You can experiment: Take a radiant electric heater outside about noon Local time (no wind). Lay in full sun for a minute. Stand in full shade for a minute. Turn on heater and stand 3 feet from it for a minute In the shade. If the heater has a 1200 watt setting try that. Don’t forget to record results.}}

    In addition, some research shows a cooler sun has a weaker magnetic field. This allows more cosmic rays from outside the solar system to strike the earth causing more clouds and cooler earth. (clouds reflect some of the sun’s energy back into space before it warms the earth.) (yes, they also reflect outgoing energy back down… less incoming, less outgoing). Also, particulate pollution (smoke, dust, volcanos) enable clouds and reflect sun energy… remember, less in, less out. Evaporation rate studies show refectance can range from 10% to 30% in some conditions.

    And more: Sea surface temperatures also affect land temperatures. Warm Pacific= El Nino, cool Pacific=La Nina. (for reasons that entirely escape me, oceanographers think sea SURFACE temperatures extend down to 700 feet, or is it meters?) For reference purposes, the last 12 months, July 2010 to July 2011, have been classified as a La Nina year. Warm Sun warm Pacific El Nino. Cool sun cool Pacific La Nina.

    A classic La Nina draws a line around the northern hemisphere at about the 40 degree latitude line. Above the line, cold wet/snow winters, stormy summers with heat. Below the line, hot dry summers, cold dry winters. La Ninas are also associated with low solar activity… few sun spots.

    Because of the elliptical orbit of the earth around the sun, the Earth (and northern hemisphere) is closest to the sun on January 6 or so giving warmer winters north and warmer summers in the southern hemisphere. This gradually changes to colder winter north and cooler summers south. The Earth also varies its tilt on its axis having a similar result. Sometimes they happen at the same time. This requires more research… could I get a grant?

    Mostly agreed upon facts: Temperatures during our time, “Recorded History” have been remarkably stable when compared to the last 600,000 years or so. The advance of continental glaciers during the last several ice ages stopped about the 40 degree latitude. (give or take). The last several warm periods, between ice ages lasted about 10,000 years. Our current warm period is about 12,000 years old. Glacial periods last about 90,000 years. Between 1645 and 1715 there were very few observable sunspots, (ie, low solar activity) This period is sometimes referred to as “The little Ice Age”

    Four possibilities: 1. The weather for the next year will be like the last year. 2. The weather for the next 75 years will have a new normal, of which last year is the best example. 3. A new Ice age is about to commence and we will get to see the beginnings, with last year’s weather being greatly longed for. 4. What I have been smoking is not what I think I have been smoking.

  68. Seriously – 0.8 C over 100 years is supposed to have caused disasters already ?

    C’mon this is just silly.

    The world temperatures seem flat for more than a decade and they all begin shouting nonsense.

    How could it have been the hottest decade on record without the temperature increasing – even going down ??

    The other thing I don’t get is the precision – we’re talking about fractions of a degree in measurements from places where the heat will burn you up to places where you need snowsuits to survive ??

    I always learnt in my science studies that if you gave an answer with more precision than your least precise result you were simply wrong !

    I don’t believe them – full stop!

  69. M.A.Vukcevic says:
    July 11, 2011 at 2:05 pm

    “Most of the ‘identified’ cycles are very little to do with celestial events, and far more to do with ocean currents and Coriolis force.”

    That was more or less my point. The various gyres are examples of modal responses of the oceanic subsystem.

  70. Here’s a cherry on on a snow cone: http://www.flatheadbeacon.com/articles/article/ultra-marathon_race_cancelled_due_to_snow/23833/

    Ultra-Marathon Race Cancelled Due to Snow

    By Associated Press , 07-11-11
    The race director of a 100-mile ultra-marathon foot race through the Flathead National Forest has cancelled the event due to lingering snow on the route that he says would make the course too dangerous for runners and likely prevent anyone from finishing within the required 36-hour limit.

    Brad Lamson tells the Missoulian that portions of the course for the Swan Crest 100 have deep snow that is concealing signs that mark trail intersections.

    He says he’s convinced the snow won’t melt in time for the event scheduled for July 29.

    He says postponing the race would pose problems with shortening daylight hours and increased grizzly bear activity.

    This is only the second year for the race. Last year, 44 people started but only 20 finished.

  71. This is a very poor analysis. A lot of timeseries tend to go up and then down and then up (eg the price of gold). You can’t just assume it’s a cycle.

    If manmade global warming is true the temperature is going to keep rising, irregardless of past changes and whether you can fit them with various curves.

    So working backwards and saying because the warming so far can be fit with curves or isn’t beyond magnitudes of past warming is illogical and bears nothing on what Richard Black was saying.

  72. My own belief is that looking at decadal temperature changes is the new trick to hide the lack of warming. (In the IPCC AR4, you will remember that is was to state the number of record years.)

    The other question to ask is why a reporter for the UK taxpayer-funded BBC should use foreign data over the UK taxpayer-funded Hadley centre. An analysis of the figures will show why – NASA GISSTEMP shows a warming trend since 2000, whereas HADCRUT3 does not. Black’s peculiar choice seems to be based on choosing the data series that best fits his story.

    I have posted a couple of graphs which demonstrate this bias.

    http://manicbeancounter.wordpress.com/2011/07/11/show-warming-after-it-has-stopped-part-2/

  73. nomnom says:
    July 11, 2011 at 3:54 pm
    So working backwards and saying because the warming so far can be fit with curves
    ===============================================================
    That’s exactly right……
    ….the climate computer games are illogical

  74. I will admit to having often wondered how much the early 20th century temp increase was due to moving away from unfiltered wood/coal burning for household heating in the developed world, and thus giving an inappropriately larger delta to the temp increase for the period. And then again in the 80s-90s as clean air regs toughened and the dirty old Soviet Union/East Euro industries tanked.

  75. The extreme AGW proponents either ignore or are unaware of the cyclic warming and cooling of the planet that correlate with solar magnetic cycle changes. (The solar magnetic cycle changes cause an increase or decrease to the solar heliosphere and solar wind which in turn results in an increase or decrease in atmospheric ionization which in turn results in less or more low level clouds which results in more or less solar energy being reflected into space.)

    The following is a review paper that discusses the mechanism and observational data that supports the mechanism by which solar magnetic cycle changes results planetary climate change.

    Atmospheric Ionization and Clouds as Links between Solar Activity and Climate
    By Brian Tinsley and Fangqun Yu

    http://www.utdallas.edu/physics/pdf/Atmos_060302.pdf

    Overall, clouds reflect more solar radiation than they trap, leading to a net cooling of
    ~27.7 W/m2 from the mean global cloud cover of ~63.3% [Hartmann, 1993].

    There are a number of paleoclimatic papers that note there is correlation with C14 and other cosmogenic isotopes changes gradual and abrupt climatic change. For example Gerald Bond’s Persistent Solar Influence on North Atlantic Climate during the Holocene which is one of a series of papers written by Bond that tracked the correlation of levels of the cosmogenic isotopes C14 and Be10 with centennial to millennial climate change.

    http://www.essc.psu.edu/essc_web/seminars/spring2006/Mar1/Bond%20et%20al%202001.pdf

    …The evidence comes from a close correlation between inferred changes in production rates of the cosmogenic nuclides carbon-14 and beryllium-10 and centennial to millennial time scale changes in proxies of drift ice measured in deep-sea sediment cores. A solar forcing mechanism therefore may underlie at least the Holocene segment of the North Atlantic’s 1500-year cycle…

    Another example is this paper which discusses the cause of the Younger Dryas abrupt climatic change which interrupted the current Holocene interglacial returning the planet back to the glacial phase.

    “Reduced solar activity as a trigger for the start of the Younger Dryas?”

    http://www.geo.vu.nl/~renh/pdf/Renssen-etal-QI-2000.pdf

    From the paper:

    “Estimates for the start of the YD all demonstrate a strong and rapid rise of C14 (Cosmogenic isotope that increases when there is decreased solar activity that hence allows increased galactic cosmic rays GCR to strike and interact with the atmosphere.) This change is the largest increase of atmospheric C14 known from the late glacial period and Holocene records.”

    http://cc.oulu.fi/~usoskin/personal/Miyahara_AG06.pdf

    The Solar Cycle at Maunder Minimum Epoch

    The Maunder minimum is considered as an example of occasionally occurring Grand minima, when the solar dynamo was in a special mode. We review available sets of direct and indirect data covering the period during and around the Maunder minimum. The start of the minimum was very abrupt and was followed by a gradual recovery of the activity. The data suggest that while the sunspot activity was greatly suppressed during the deep phase of the minimum, the cyclic dynamo kept working around the sunspot formation threshold level, leading to seemingly sporadic occurrence of sunspots.

    Cosmogenic isotopes are produced in the Earth’s atmosphere mainly by galactic cosmic rays, which originate from outside of the heliosphere and are modulated by the solar wind and interplanetary magnetic field. The basics of the modulation process are well understood (see, e.g., Refs. 20 and 21), and the attenuation level of cosmic rays in the heliosphere depends on the strength and level of turbulence of solar magnetic field and on the global structure of the heliosphere. Basically, the flux of cosmic rays impinging on the Earth is inversely correlated with the solar activity, but shows also variations depending on, for example, the polarity of solar magnetic field.

    Cosmogenic isotopes provide the most extendable indirect data on the cosmic ray flux, the state of the heliosphere, and hence on the solar magnetic activity during the past. The most commonly used cosmogenic isotopes are radiocarbon (i.e., 14C) and 10Be, which are measured in tree-rings and in ice cores, respectively. Both tree-rings and ice cores form stratified structures and retain the time variations of the abundance of isotopes in each layer.

    14C and 10Be are produced in the atmosphere as a result of nuclear reactions of cosmic rays with the atmospheric nuclei. Then 14C is oxidized to form carbon dioxide and circulates within the carbon cycle between different reservoirs, some of which are very inertial, and it gets eventually absorbed by trees by means of photosynthesis. On the other hand, 10Be becomes attached to aerosols, precipitates with snowfall and is accumulated in the ice in polar regions.

    Another example is this paper which discusses the cause of the Younger Dryas abrupt climatic change which interrupted the current Holocene interglacial returning the planet back to the glacial phase.

    “Reduced solar activity as a trigger for the start of the Younger Dryas?”

    http://www.geo.vu.nl/~renh/pdf/Renssen-etal-QI-2000.pdf

    From the paper:

    “Estimates for the start of the YD all demonstrate a strong and rapid rise of C14 (Cosmogenic isotope that increases when there is decreased solar activity that hence allows increased galactic cosmic rays GCR to strike and interact with the atmosphere.) This change is the largest increase of atmospheric C14 known from the late glacial period and Holocene records.”

  76. Pretty impressive looking analysis.

    I still think, despite the ‘consensus’, that late 20th century warming was mostly from the sun, c02 having a very small role, why? the slope is the same as when we know its was the sun without any c02-like in MWP. Late 20th century warming is just a heat time lag from increased solar output from ~1750-1950, like the ~6 weeks after the summer solstice when when T continues to rise, despite the decreasing solar rays “going in opposite directions” to the continued warming.

    Truth will out, but this is a very good anaylysis above.

  77. http://www.fao.org/docrep/005/y2787e/y2787e06.htm

    5. LONG-TERM AND SHORT-TERM TIME SERIES OF GLOBAL CLIMATIC INDICES AND FISH STOCK
    The most pronounced spectral maximum of the long-term fluctuations for all “long-term” time series (excluding anchovy) varies within the interval of 54-58 years. The corresponding climate cycles (both measured and reconstructed) vary within the range of 50-65 years (in average, 56 years).

  78. “All these things have causes, and for some of the warming that has occurred in the later part of the 20th and into the 21st century, when all other known factors are excluded, including solar cycles, (yes, solar cycles have long been known to affect temperatures) the only known factor that remains is the anthropogenic fingerprint of greenhouse gas increases.
    Might there be some other, as yet unidentfied, cause? Absolutely! And if there is, it is only through the hard work of climate research that it will be discovered and quantified.”

    The Argument from Ignorance, writ large. “The only known factor”, indeed.

  79. Bart says:
    July 11, 2011 at 1:15 pm
    The distinction is important because, the first argument you will get against the idea is that there is no known forcing with a ~60 year period.

    That’s because Climate Science is married to CO2.and is not allowed out of the house on their own.

    Jupiter and Saturn have a 60 year orbital harmonic (12 and 30 years). Over time, even a very small cyclical forcing will have a large effect if any of the systems on earth resonant at the same frequency. Earth’s tides for example, are much larger than can be explained by simple linear forcings.

    All objects have resonant frequencies and the larger the object the longer the period. Until the natural frequency(s) of the earth’s climate systems is known, it cannot be ruled out that there is a 60 year natural harmonic. Given the age of the earth and solar system, nature has had a very long time to shape the earth and oceans to match the cyclical forcings of the heavens.

    The notion that something doesn’t exist because we haven’t found it only makes sense in the case of objects that are unlikely. There is nothing unlikely about cyclical natural behavior, including climate cycles. What is unlikely is non cyclical behavior. What should be assumed is that no event in nature is non cyclical until proven otherwise.

  80. Anna Lemma says:
    July 11, 2011 at 10:01 pm
    The Argument from Ignorance, writ large. “The only known factor”, indeed.

    Exactly. Science routinely demonstrates that the set of things we don’t know about any subject is larger than the set of things we do know. Climate science is like an adolescent child thinking they know it all, because they have no idea of how much there is yet to learn.

  81. I get the impression that statistics in climatology is meaningless not only does it not solve the problem it can’t even eliminate anything.We are told we are cherry picking however we look at these statistics.It could be that what we need is a better understanding of how the Earth’s climate works before statistics could be any use.

  82. nicola scafetta says:
    July 11, 2011 at 11:13 am
    Dear Vukcevic,
    a quasi 60-year cycle in the climate has been observed by a lot of people in a lot of climate records..

    Dr. Scafetta
    Thank you for your note. I am fairly familiar with harmonic and quasi-harmonic oscillations and the cross-modulation products. When Dr. Hathaway of NASA was predicting largest solar cycle, I published this

    http://www.vukcevic.talktalk.net/NFC7.htm

    and subsequently was declared ‘cyclomaniac in supreme’ by couple of other solar scientist.
    I have also travelled down the ‘climate cycle’ road (see last graph in: http://www.vukcevic.talktalk.net/SSA.htm ) but eventually realism prevailed.

  83. To N. Scafetta.
    I read your paper on Climate change causes and its prtty much the same as what I have been coming to over hte last 3-4 years.

    Variations in 20th century trends which do not correlate to c02 are routinely dismissed as either aerosols or heat going into the oceans, when it is very clear these are related to PDO cycles, which means climate sensitivity to c02 must be overstated. It is also clear that temperatures change more than expected due to the 11 year solar cycle, which means sensitivty to solar changes must be under-stated. These are empirical observations. It is also clear that c02 degasssing from oceans is not incorporated into the models from solar variations at all. I came to all these conclusions the same as yourself, but you have put them in graphical and mathematical form. Many of these are emprirical and quite strong, and the truth will out in the end.

    I also add to your general theme the idea that time lag with respect to solar irradiance can be up to 40 years, which is evidenced in both solar proxies and also in daily and seasonal changes (eg warmth max 6 weeks after the summer solstice).

    Good paper anyway, still got more reading to do on it.

    Regards.

  84. “Seeing as it’s logically impossible that the world warmed between 1997 and 2007, cooled between 1998 and 2008, and warmed again from 1999 to 2009 …”

    My dear Mr. Black, given the way historical, measured temperatures are forced to dance up and down at the whim of whichever climate alarmist happens to be manipulating them today, the only logical impossibility around here is that any scientific knowledge might ever be gleaned from the resulting “evidence”.

  85. Whilst I have severe reservations regarding the accuracy of the temperature record (given siting issues, coverage, stations drop outs, UHI, man made manipulation & continued revisions, etc), what would appear to be the case is that there is little temperature difference between the decade of the 1990s and that of the 2000s.

    On that basis since there has been little change during the past 12 to 15 years, IF extreme weather events are due to warming, would one not have expected to see just as many and similar extreme events in the period from the mid 1980s through to say the late 1990s as one sees today?

    The fact that there has on any basis been little further warming over the course of the last 10 to 15 years over and above that which had already occured by the mid/late 19902 suggests that recent extreme weather events are not the consequence of additional warming (there having been all but none these past 15 years) and therefore must be due to natural variability of weather events in an ever changing and chaotic world in which we live.

  86. Bart [July 11, 2011 at 9:48 am] says:

    Bart, thanks very much for this comment and the links.

  87. Bart,

    Your comment “rang a bell” in my head. There’s a 2001 paper by Davis & Bohling in which they demonstrated both the ~1,000-yr and ~60-yr cycles in the GISP2 ice core…

    Davis & Bohling, Fig. 6

    Davis & Bohling, Fig. 7

    They also identified possible harmonics at ~160-yr and ~320-yr; but these were relatively weak.

  88. M.A.Vukcevic says:
    “Thank you for your note. I am fairly familiar with harmonic and quasi-harmonic oscillations and the cross-modulation products.”

    Vukcevic, I hope that you do not think that you are the only person on the Earth who is familiar with harmonic and quasi-harmonic oscillations and the cross-modulation products.

    As I said above there are a lot of people that found a quasi 60-year cycle in several records.

    Another record has been referenced by Middleton above.
    Please give a look at
    Davis & Bohling, Fig. 7

    As also ferd berple says:
    Jupiter and Saturn have a 60 year orbital harmonic (12 and 30 years). Over time, even a very small cyclical forcing will have a large effect if any of the systems on earth resonant at the same frequency.

    So, there is a natural 60-year cycle and has an astronomical meaning. Actually this was the topic of my paper

    N. Scafetta, “Empirical evidence for a celestial origin of the climate oscillations and its implications”. Journal of Atmospheric and Solar-Terrestrial Physics 72, 951–970 (2010), doi:10.1016/j.jastp.2010.04.015

  89. Dr. Scafetta thank you for the further elaboration. Regarding the comment

    http://wattsupwiththat.com/2011/07/11/the-bbcs-richard-black-engages-in-goldilocks-picking/#comment-698615

    I would like to point that the reliability of the Greenland ice core data is coming under strong scrutiny. My observations are here: http://www.vukcevic.talktalk.net/CET&10Be.htm
    The rest of your comments are appreciated, but would not whish to waste either your or my time in qualifying merits of the evidence.

  90. thingadonta says:
    July 12, 2011 at 12:21 am

    “Variations in 20th century trends which do not correlate to c02 are routinely dismissed as either aerosols or heat going into the oceans, when it is very clear these are related to PDO cycles, which means climate sensitivity to c02 must be overstated.”

    Yep, right on the money. But Gaia Modelers don’t do natural processes aside from heat transfers caused by radiation from the sun. As they admit (when not thinking about its implications), ENSO is an “emergent property” in the Gaia Models. They remain scientists, so-called, who have created no physical hypotheses that go beyond the 19th century work of Arrhenius.

  91. ferd berple says:
    July 11, 2011 at 10:41 pm

    “Given the age of the earth and solar system, nature has had a very long time to shape the earth and oceans to match the cyclical forcings of the heavens.”

    It does not need to. All you need is a lightly damped natural frequency mode and random noise which has energy in the appropriate band forcing it.

    “The notion that something doesn’t exist because we haven’t found it only makes sense in the case of objects that are unlikely. There is nothing unlikely about cyclical natural behavior, including climate cycles. What is unlikely is non cyclical behavior. What should be assumed is that no event in nature is non cyclical until proven otherwise.”

    Well stated. Natural frequencies of physical systems are… Natural. Ubiquitous. Universal. And, when you have fully two cycles of a 60 year oscillation evident within the higher accuracy, directly measured data spanning the previous century, and it appears all over the place in proxy reconstructions over thousands of years as well… Then, by gum, there’s a 60 year quasi-cyclic phenomenon influencing global temperatures.

  92. nicola scafetta says:
    July 12, 2011 at 8:33 am

    “So, there is a natural 60-year cycle and has an astronomical meaning.”

    I want to emphasize what I said above once again:

    All you need is a lightly damped natural frequency mode and random noise which has energy in the appropriate band forcing it.

    No additional outside source is needed.

  93. I want to bring up the example of the Tacoma Narrows Bridge again. If you time it, you can see that the torsional mode of the bridge has a period of about 4 seconds.

    There is no 0.25 Hz excitation – there is only the broadband excitation of the wind. The bandwidth of that wind input increased on that blustery day such that it started feeding energy into the mode. The bridge collapsed because the input energy could not be dissipated faster than the input energy before fatigue set in and the materials lost their integrity.

    In the general case, if the system does not fatigue and fail, a steady state is reached whereby the oscillations are large enough that output energy balances input energy. Then, you get quasi-periodic, steady state oscillations which are effectively amplitude and frequency modulated within some range of the equilibrium.

    This is not some revolutionary new theory. I’m just applying principles which have been known for at least 80 years.

  94. The bridge collapsed because the input energy could not be dissipated faster than the output energy…

  95. Dang it… the rate of energy dissipation to be output was slower than the rate of input energy. That is what I mean.

  96. Bart says:
    July 12, 2011 at 9:38 am
    ………
    I would, in general, agree with the above. The PDO, AMO, and SOI/ENSO (11 year m.a.) come closest to show kind of quasi cycles, but none of them have 60 year period:

    http://www.vukcevic.talktalk.net/A&P.htm

    It is also obvious that Atlantic cycles (AMO) are of different periods to the Pacific, and there again the North Pacific(PDO) is different to the South Equatorial Pacific (SOI/ENSO).
    My conclusion is that these are locally induced oscillations, rather than an outside fixed periodicity induction. I attribute it to the ocean currents ‘circular’ motion, whereby time variable velocity is contributing to ‘cycles’ irregularity; see: http://upload.wikimedia.org/wikipedia/commons/6/67/Ocean_currents_1943_%28borderless%293.png

  97. M.A.Vukcevic says:
    July 12, 2011 at 10:39 am

    “… none of them have 60 year period…”

    It looks to me that there is a roughly 60 year periodicity in your AMO plots.

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