Aproxymations

Guest Post by Willis Eschenbach

Over at Bishop Hill, the Bish has an interesting thread about a new proxy reconstruction by Rob Wilson et al. entitled “Last millennium northern hemisphere summer temperatures from tree rings: Part I: The long term context” , hereinafter Wilson 2016. The paper and the associated data are available here. They describe the genesis of the work as follows:

This work is the first product of a consortium called N-TREND (Northern Hemisphere Tree-Ring Network Development) which brings together dendroclimatologists to identify a collective strategy for improving large-scale summer temperature reconstructions.

At first I was stoked that they had included an Excel spreadsheet with the proxy data. Like they say in the 12-step programs, Hi, my name’s Willis, and I’m a data addict … anyhow, here’s a graph of all of the data, along with the annual average in red.

53 proxies wilson 2016Figure 1. Plot of the proxy data from the Wilson 2016 Excel worksheet. All proxies cover the period 1710 – 1988, as indicated by the vertical dotted lines. Note what happens to the average at the recent end.

But as always, the devil is in the details. I ran across a couple of surprises as I looked at the data.

First, I realized after looking at the data for a bit that all of the proxies had been “normalized”, that is to say, set to a mean of zero and a standard deviation of one. This is curious, because one of the selling points of their study is the following (emphasis mine):

For N-TREND, rather than statistically screening all extant TR chronologies for a significant local temperature signal, we utilise mostly published TR temperature reconstructions (or chronologies used in published reconstructions) that start prior to 1750. This strategy explicitly incorporates the expert judgement the original authors used to derive the most robust [temperature] reconstruction possible from the available data at that particular location.

So to summarize the whole process: for most of the data used, it started out as various kinds of proxies (ring width, wood density, “Blue Intensity”).

Then it was transformed using the “expert judgement of the original authors” into temperature estimates in degrees celsius.

Then it has been transformed again, this time using the expert judgement of the current authors, into standard deviations based on the mean and standard deviation of the period 1750-1950. Why this exact period? Presumably, expert judgement.

Finally, it will be re-transformed one last time, again using the expert judgement of the current authors, back into temperatures in degrees celsius

This strikes me as … well … a strangely circuitous route. I mean, if you start with proxy temperatures in degrees C and you are looking to calculate an average temperature in degrees C, why change it to something else in between?

It got odder when I analyzed the authorship of the temperature records reconstructed from the 53 proxies. In 48 of the proxy, the original lead author is also an author on this paper. It is true that they said this study is the result of a consortium of dendroclimatologists. However, I had expected them to look at more tree ring temperature reconstructions from other authors. So when they say they depend on the expert judgement of the authors of the proxies, in more than 90% of the proxies studied, they are merely saying they trust their own judgment.

And indeed, they think quite highly of their own judgement. rating it “expert”.

But since that is the case, since they are depending on their own prior transformation of a record of, e.g., tree ring width in mm into an estimated temperature in degrees C, then why on earth would they convert it out of degrees C again, and then at the end of the day convert it back into degrees C? What is the gain in that?

My second surprise came after I’d messed with the actual data for a few hours, when I got around to looking at their reconstruction. They describe their method for creating their reconstruction as follows:

3. Reconstruction methodology

A similar iterative nesting method (Meko, 1997; Cook et al., 2002), as utilised in D’Arrigo et al. (2006) and Wilson et al. (2007), was used to develop the N-TREND2015 NH temperature reconstruction. This approach involves first normalising the TR data over a common period (1750 – 1950), averaging the series to derive a mean series and iteratively removing the shorter series to allow the extension of the reconstruction back (as well as forward) in time. Each nest is then scaled to have the same mean and variance as the most replicated nest (hereafter referred to as NEST 1) and the relevant time-series sections of each nest spliced together to derive the full-length reconstruction. For each nest, separate average time series were first generated for 4 longitude quadrats (Fig. 1). These continental scale time series were then averaged (after again normalising to 1750 – 1950) to produce the final large-scale hemispheric mean to ensure it is not biased to data rich regions in any one continent. 37 backward nests and 17 forward nests were calculated to produce the full reconstruction length from 750 to 2011.

Like the song says, “Well, it was clear as mud but it covered the ground” … I was reminded of a valuable insight by Steve McIntyre, which was that at the end of the day all these different systems for combining proxies are simply setting weights for a weighted average. No matter how complex or simple they are, whether it’s principal components or 37 backwards nests and 17 forwards nests, all they can do is weight different points by different amounts. This is another such system.

In any case, that explained why they put the normalized data in their spreadsheet. This normalized data was what they used in creating their reconstruction.

I got my second surprise when I plotted up their reconstruction from the data given in their Excel worksheet. I looked at it and said “Dang, that looks like the red line in Figure 1”. So I plotted up the annual average of the 53 normalized proxies in black, and I overlaid it with a regression of their reconstruction in red. Figure 2 shows that result:

average and interative reconstruction 53 proxiesFigure 2. Annual average of 53 proxies (black), and linear regression of Wilson 2016 iterative nested reconstruction. Regression is of the form Proxy_Average = m * Reconstruction + b, with m = 1.25 and b = 0.54.

All I can say is, I hope they didn’t pay full retail price for their Nested Reconstruction Integratomasticator. Other than the final data point, their nested reconstructed integrated results are nearly identical to a simple average of the data.

Finally, as you can see, in recent times (post 1988) the fewer the proxies, the higher the estimated temperature. This is abated but not solved by their method. We can see what this means by restricting our analysis to the time period when all of the proxies have data.

average and interative reconstruction 53 proxies 1900 onFigure 3. As in Figure 2, annual average of 53 proxies (black), and linear regression of Wilson 2016 iterative nested reconstruction (red). Blue lines show proxy data.You can see how the number of proxies drops off after 1988 by the change in the intensity of the blue color.

Again you can see that their reconstruction is scarcely different from the plain old average of the data. As you can see, according to the full set of proxies the temperature in 1988 was lower than the temperature in 1950, and there is no big hockey-stick in the recent data up to 1988. After that the number of proxies drops off a cliff. By 1990, we’ve already lost about 40% of the proxies, and from there the proxy count just continues to drop.

In closing let me add that this post is far from an exhaustive analysis of difficulties facing the Wilson 2016 study. It does not touch any of the individual proxies or the problems that they might have. I hope Steve McIntyre takes on that one, he’s the undisputed king of understanding and explaining proxy minutiae. It also doesn’t address the lack of bright-line ex-ante proxy selection criteria. Nor does it discuss “data snooping”, the practice of (often unconsciously or unwittingly) selecting the proxies that will support your thesis. I can only cover so much in one post.

My conclusions from all of this:

• Transforming a dataset from tree ring widths in mm to temperatures in degrees C, thence to standard deviations, and finally back to degrees C, seems like a doubtful procedure.

• Without seeing the underlying data, it is hard to judge the full effects of what they have done. While having the normalized datasets is valuable, it cannot replace the actual underlying data.

• Whatever their iterative nested method might be doing, it’s not doing a whole lot.

• I do not know of any justification for normalizing the proxies before averaging them. They are already in degrees C. In addition, normalization greatly distorts the trends a time series, in a manner that depends on the exact shape and variance of the time series.

Finally, to a good first approximation their reconstruction is the same as the annual average of the normalized data. That means their method uses the following process:

Transform the "expert judgement" proxy temperature estimates from degrees C to units of standard deviations.

Average them.

Transform them back to degrees C using linear regression.

I’m sorry, but I simply don’t believe you can do that. Well, you can do it, but the result will have error bars from floor to ceiling and will have little to do with temperature.

El Niño rains here tonight. We’ve gotten four inches (10 cm) in the last four days, and it’s supposed to rain on and off for a week … great news here in drought city.

Best of life to all, sun when you need it, rain when it’s dry, silver from the five-day-old moon far-reaching on the sea …

w.

My Usual Request: If you disagree with me or anyone, please quote the exact words you disagree with. I can defend my own words. I cannot defend someone’s interpretation of my words.

My Other Request: If you think that e.g. I’m using the wrong method on the wrong dataset, please educate me and others by demonstrating the proper use of the right method on the right dataset. Simply claiming I’m wrong doesn’t advance the discussion.

320 thoughts on “Aproxymations

  1. Thanks Willis, as usual an excellent analysis. ” Then it was transformed using the “expert judgement of the original authors” into temperature estimates in degrees celsius.” This means the author’s opinion is passing as data. They, the authors apparently live in a virtual reality world.

    • Willis may I suggest an even better new word? Aproxymachination? A+proxy+machination-
      machination- “a scheming or crafty action or artful design intended to accomplish some usually evil end”

      • I’m not convinced there’s any conscious scheming going on here. There remain, however, severe doubts concerning the validity of dendroclimatology in se., combined with deep statistical jiggeripokeriation, possibly immense error limits, and (those dread words) weighted averages.

        That was my first thought upon seeing this new hockey stick. Mann got his hockey stick by weighting certain defective series by a factor, IIRR, of 350, an obscenity, though derived via such a complex statistical rigamarole that even Mann may not have realized the magnitude of it, until it was pointed out by McIntyre/McKitrick, leading to much crying ‘aieee!’ and weeping and gnashing of teeth, I’m sure.

        I’m hoping that the esteemed Dr. Wilson and his consorts will be left with something robust when the dust settles. They have certainly behaved admirably in their willingness to engage at Bishop Hill, among other things.

    • OK Willis, we already knew that one can use tree rings to tell accurately what past Temperatures were; I think you may even have told us how that is done; even with just a single tree; so long as it is scrawny enough.
      Well Charlie Brown’s Christmas tree would be a perfect thermometer of the past.

      But what I would like to know is:

      What do think of the possibility that one might even be able to use tree rings; given enough trees, to estimate roughly what the age of a tree might be ??

      Anyhow, welcome to 2016 Willis.

      G

    • unless the samples are all the same length, combining them is generally going to generate rubbish, because some will be from warm regions and others from cold regions. the smaller the sample size, the less random the distribution, the greater the garbage.

      • OK, I averaged all 54 data series from 1710 to 1988. The period for which they all have data. Then I plotted the results without any statistical nonsense. Here is the result. As can be seen temperatures have been rising steadily since the early 1800’s, long before CO2 was an issue.

        This is VERY STRONG evidence that CO2 is not the cause of the current warming!!

      • To Michael Janowski –

        If you plot is from this dendro paper’s data, they are suggesting a 3-4C rise in NH temps over the period 1840-2010.

        Amazingly, they have not used “It’s worse than we thought” as a rise of this magnitude would seem to be much more than any other reconstruction. Most thermometers must also require calibration.

      • they are suggesting a 3-4C rise in NH temps over the period 1840-2010
        ===================
        That is not supported by the data. If you look at my graph above the range on the 30 year average (the common measure of climate) is approximately 1.2 C.

        You might be able to get a 3-4C rise if you take the min of the early 1800’s and the max of the early 2000’s, but that is misleading at best, because then you are measuring weather, not climate.

    • Well, you know the old saw, “If you can’t dazzle them with your brilliance, baffle them with your bullsh-t.”

    • Colour me stupid, but I thought the thunderingly clear lesson from the divergence problem was “Trees aren’t thermometers”. Dendrochronology makes sense to me. I really loved the book “Exodus to Arthur” by Mike Baillie, but he made very clear that trees responded to temperature, or moisture, or basically whatever they felt like responding to, and that there wasn’t one fixed rule. A signal from the trees over a wide area is a sign that *something* happened, but not an unambiguous sign of *what*, and in that book he looked to ice cores and historical records to find out what. After reading some of Douglass Keenan’s papers at http://www.informath.org/ I am obliged to take even dendrochronology somewhat more warily; even if the trees might on occasion be reporting the temperature their reports may well be ascribed to the wrong times. (Not through malice. This kind of stuff looks to be pretty hard to do right.)

    • It’s all just slight of hand isn’t it? Pontification for obfuscation? It’s thousands of hours and dollars and words that end up just being one more example of “science done backwards/incorrectly/inaccurately”.

  2. I’m sure a lot if sincere work has gone into this original paper. I always, however, have a huge issue with using tree ring data somehow to estimate historical temperatures, especially over the long term. To state the bleedin’ obvious, it’s just not as simple as that – it cannot be.
    The main determinant of tree growth where I live (Surrey, south of London) is, I am certain, water supply, not temperature and, no, rainfall cannot be used as a proxy for temperature (certainly not around here anyhow). Further, what about the effects of, inter alia, soil fertility, parasite and general invertebrate activity, tree diseases and, dare I say it, air fertility including varying levels of that dreadful poison CO2? How are these taken account of in tree rings?
    I’m sure tree rings are terribly interesting and indeed you may be able to infer some isues from them but, as Willis so succinctly evaluates, if you look at one factor like temperature, the error bars must be so huge as to render the (reconstructed) “data” meaningless.
    Proper science please – not starting with the desired solution and corrupting data relentlessly until you have got a correlation.

    • I can see how you can use tree rings to correlate major climatic events, such as the slowdown in growth caused by a major eruption, like a Krakatoa magnitude eruption.

      However, to try and define temperatures from tree rings on an annual basis is just plain voodoo, because of:

      1. Rainfall variations.

      2. Shade variations from other trees.

      3. Fertilisation from nearby forest fires.

      4. Fertilisation from the occasional animal dump.

      5. Nitrate boost from lightning storms.

      6. Variations in growth depending on the side of trunk.

      7. Occasional insect infestations on leaves.

      8. Variations in competition from roots of nearby trees for water and nutrients.

      9. Variation in ring widths depending on the age of the trees.

      10. Variation in soil temperatures depending on slope direction.

      I have seen much more comprehensive lists, but the bottom line is this: the only place you can magically transform BS readings into ‘hard facts’ is in climate science, where the use of voodoo statistical techniques is considered both acceptable and normal.

      • Peter
        Your list plus co2 is a good one. To it can be added the trees relative position in a forest which over centuries might range from the edge to the centre to the edge again as other trees grow and die. That all effects shade, water supply, competition for nutrients etc. Let us also remember that this is for summer growth only.

        Rob has made a good effort and he is to be congratulated for defending the article over at bishop hill.

        However after having read many papers, technical books and attended a short course I still cannot see how the data can be translated to a reliable temperature proxy accurate to tenths of a degree Celsius. Some sort of approximation to moisture, yes, but temperature?

        However I am prepared to be convinced so feel it would be interesting if one of the authors could be persuaded to supply an article for discussion here that clarifies how tree ring data can be reliably translated to a useable and useful northern hemisphere summer temperature proxy
        tonyb

      • Not to mention that the growth of trees can fundamentally change the environment where the trees are growing, and that it changes the growth of the trees, which again changes the environment, (just look at what happens to all the abandon Christmas tree farms scattered across the U.S.), I think you would need about 5 or 6 tree generations, in a specific location, to even get a handle on the way that trees can change their own environment. Since Mann started the tree-ring-schtick 15-20 years ago, and a generation of trees can be anywhere from 80 to 400 years this research only has about 2380 years to go until the “science is settled.”

      • Many claim that CO2 was constant before the industrial age began. It is well known that CO2 is a restricting factor on tree growth.

        It is therefore a given that tree growth, represented by ring width, increases as the CO2 concentration in the atmosphere increases, a fact exploited by modern horticulture.

        The increase in tree ring width caused by the additional CO2 has not been subtracted from the proxy result. This biases the ‘temperature’ upwards because both the temperature and the CO2 are known to have risen since 1750, but the combined effects are being attributed to only the temperature.

        It is well known that both temperature and CO2 concentration combine to create the tree rings. How then can the temperature signal be extracted directly from the resulting series of widths if the CO2 concentration changed? It cannot. For any period of tree ring data for which there is a known CO2 data set, the effect on growth by rising CO2 must first be subtracted from the ring-only result in order to obtain the temperature.

        This is so obvious I shouldn’t have to make analogies.

        The most important contributors to a ring width are temperature, CO2 level and water. Let’s assume the rainfall averages over time to be constant. We know full well the CO2 has risen and when and approximately by how much. The fact that the number of proxies drops off at the end is noted. But the jump in the ring width signal must first be corrected for CO2 before acceptance as a temperature proxy.

        Michael Mann’s infamous ‘hockey stick chart’, even if badly constructed, is a CO2 concentration plot more than it is a temperature chart, particularly in the modern era. If the effect of CO2 fertilisation is subtracted from the ring widths, the ‘temperature blade’ is truncated. Similarly if the upturn in this study’s ‘temperature chart’ at the end is first corrected for CO2 fertilisation (using available records) there is a ‘temperature’ deduction throughout the modern age.

        Whether wonky statistical techniques are used or not, a tree ring width has to be corrected for CO2 availability before the temperature signal can be extracted. Once the CO2 hockey stick growth is subtracted from the tree ring width hockey stick, the remaining basically flat line proves that tree rings provide a poor record of temperature.

      • Inspired by other contributions I can add:

        The tree ring width minus CO2 fertilisation gives a pretty flat line which represents the rainfall. I said above the rainfall could be assumed to be constant. A warm, wet, sunny summer completely offsets a long cold winter. There is no meaningful temperature signal in them thar rings. It is rainfall plus CO2. Subtract the effect of known CO2 variation and the result is the available moisture.

      • I live alongside a lake, on low, though forested property. The river running through the lake was dammed in the 50s, raising the lake level somewhat. That, plus increased boating since then caused the shoreline to erode and move inland some 30, or so, feet, causing some large trees to fall into the water. In an effort to stabilize the shore, I have removed several dozen trees from the lake, and lined the shore with more rocks. The tree rings are quite interesting.

        Some of the larger trees had as many as 100 rings. They all showed variable growth, until the last couple of decades. Then the rings got closer and closer together, until they finally ended. Looking at the rings only, several conclusions could be made. 1) We are entering a period of Catastrophic Global Cooling, and it’s now too late. 2) We are entering a period of Catastrophic Global Warming, causing sea levels to rise, and it’s now too late. 3) Waves from water skiing kills trees. It’s politics, not science that determines the correct answer.

      • Excellent summary of some of the reasons to be very skeptical that the width of tree rings can give a value for the temp of the Earth.
        To these I would add a few thoughts.
        It is rather well established that most trees grow best when there is a cold winter with no big warm ups, followed by a wet spring with few extremes.
        And extreme and fluctuating conditions is known to hinder growth as well…extremes such as late frosts and freezes, early hot periods with insufficient soil moisture, excessively wet and cloudy conditions that persist for an extended period of time (which can cause root die-off due to soil fungi), etc.
        In short, the way that moisture, temperature, periods of clouds and sun, and other such factors interact is more important than any single variable or even combinations of variables.
        In a given area, the Goldilocks formula for optimum growth is likely to be average conditions (in other words, zonal flow in the jet stream) over long periods. Extreme conditions of any sort have the tendency to interrupt this optimum growth.
        Heat can hinder growth of trees, and thus be negatively correlated with growth, under several distinct and separate circumstances.

        Where is the logical justification given that backs up such studies?
        Do the papers themselves contain such justification, or are these results given based on the assumption that wider tree rings mean warmer overall average temps in that season?
        As Ian noted, moisture is the primary determinant of growth in many areas, including arid climate zones.

      • If you think this stuff is good, you should look into the CO2 proxies Mann used. They’re based on boron isotopes in fossil marine plankton (foraminifera to be exact). A relationship between atmospheric CO2 and dissolved oceanic CO2 is proposed, then a relationship between boron isotopes and foraminifera shells is proposed. Not only are there errors introduced in each level of abstraction, we know from Henry’s law that oceanic CO2 concentration is dependent on temperature. Yet Mann and others saw fit to produce atmospheric gas concentration estimates purported to be precise to parts per million, which is plainly absurd.

        This is really the fundamental and inarguable failure of paleo climate modeling; there are no measurements available to support it and there never will be. Anyone who tells you they know what the temperature of the planet was before the thermometer was invented, with any precision approaching 1 degree centigrade, is lying.

      • What seems to be ignored in most paleoclimatology work is the recorded human observations that relate to any given period. Humans have had to pay attention to changes in other living things in order to survive. This is particularly true of all efforts relating to agriculture and fisheries, because these directly impacted food supply. I don’t know (there is a lot I don’t know) whether or not anyone has tried to assess what, if any, relationship (or association) there might be between recorded observations other than climatological (or meteorological) and dendrochronology. This is all interesting “stuff”, but hardly the fodder for policy.

      • Continuing from Peter Miller….

        sunshine/shade variation due to clouds

        variation due to diseases

        effect of varying humidity

        effect of different soils/ geological substrate

        fault density and orientation- effects on groundwater supply………………so it continues

    • My difficulty with tree rings is tht when one looks at a complete cross-section in the majority of cases there is no consistency in the width of the rings. As the results from a core taken from one part of a tree are likely to differ widely from another core. That cross-section that Mann proudly leans on in the “classic” portrait of him illustrates the problem beautifully.

    • “the error bars must be so huge as to render the (reconstructed) “data” meaningless.”
      Which is exactly what is wrong with the current surface temperature data, and yet climate scientist still believe it can be used to seed models and spot trends…

    • I did a small study of tree ring data on my tree farm in Alaska (pines) and knew when they were planted, the monthly precipitation, and the monthly temperature. There was almost no correlation with yearly temperature and the highest correlation was with precipitation in the spring growing period.

      • Charles, I wrote my comment above before reading your comment. I have also been involved with commercial plant and tree production.
        I believe your simple and understated comment far more readily than I believe that tree rings from a selection of separate locations can be used to infer the temperature of the Earth (even if there was such a thing).

      • …but before submittal, be sure to put the phrase “and could be related to man-made affects on the climate” at the very end, regardless of the non-sequitur it creates.

      • Be sure to refer to it as “robust.” There are still a few people who haven’t tumbled to the fact that “robust” means balderdash.

      • And when the paper is done, go the your local toy store and buy the latest model of a WWII airplane. Then go home, put the paper on top of the model, and add a line saying your paper is based on the “latest model”.

      • This study was done several years ago. When I return home from my seasonal migration to warmer climes, i will see if i can find the data.

    • Now that would be any interesting study: tree ring width as a function of both temperature and CO2, other factors held constant. I wonder if anyone’s done that?

  3. Don’t you think there’s a bit of hypocrisy in writing:

    “I’m sorry, but I simply don’t believe you can do that.”

    And:

    “If you think that e.g. I’m using the wrong method on the wrong dataset, please educate me and others by demonstrating the proper use of the right method on the right dataset. Simply claiming I’m wrong doesn’t advance the discussion.”

    • Sammydj:

      You ask

      Don’t you think there’s a bit of hypocrisy in writing:

      “I’m sorry, but I simply don’t believe you can do that.”

      And:

      “If you think that e.g. I’m using the wrong method on the wrong dataset, please educate me and others by demonstrating the proper use of the right method on the right dataset. Simply claiming I’m wrong doesn’t advance the discussion.”

      There is a lot of hypocrisy – and falsehood – in your selective quotation out of context!

      Willis Eschenbach (WS) wrote

      I’m sorry, but I simply don’t believe you can do that. Well, you can do it, but the result will have error bars from floor to ceiling and will have little to do with temperature.

      That is very, very different from his having only written “I’m sorry, but I simply don’t believe you can do that” as you have suggested he did.

      And WS explained that what he “don’t believe you can do” is to “transform” (i.e. alter) data according to “expert judgement” (i.e. personal opinions) without introducing very large uncertainty (i.e. “error bars from floor to ceiling” for temperature indications because the alterations are to fulfill opinions and not measured temperatures). Every scientist would share that ‘belief’.

      So, if you disagree that altering data according to opinions would provide “error bars from floor to ceiling and will have little to do with temperature” then say why because your saying that would fulfill the second statement of WS that you have quoted.

      Richard

    • Sammy, since you seem to have asked this question of the air, rather than a particular person, I will answer as if asked of me.
      My answer is: No, I do not believe these statements are in any way hypocritical.

  4. As usual, a good post Willis. It seems these guys think they can baffle the critics by making things much more complex than they really are. Given the tenacity with which guys like you and Steve Mc attack data you’d think they would ensure that their methods add something to the debate. And if you are play the expert judgment card it must be the first card revealed, not half way thru the hand – in other words, they have to quantify in advance the rules of applying their expert judgment.

  5. Interesting, the sudden and steep post-war drop . The only thing is that it happens in 1955 and not 1946. Looks like trees must have started using engine room intakes somewhat later than merchant shipping fleets.

    • More seriously that is an interesting independent witness that there was some climatic change at that time . There is an anomalous kink in the temperature record at that time. This suggests it is real and not something that needs “correction”.

      • It would be good to remove at least part of the 1940s blip, but we are still left with “why the blip”.

        Tom Wigley to Phil Jones Sep 27, 2009

  6. The first thing one sees is the original “hockey stick” graph–a long period of (at most) narrow and superficial change, leading up to a final open-ended increase. Knowing what we know of the Medieval and other warm periods, to say nothing of the Little Ice Age, isn’t it time simply to drop tree-rings as a temperature proxy? I agree with Willis. If anything, he is too kind. I agree with Ian also, that rainfall, not temperature, is the most likely factor generating tree-ring widths.

    • Exactly. When I look at tree stumps, I see narrow rings on one side of the stump but the same rings are thick on the other side. The next tree stump over can show varying ring thickness on the reverse sides, then in another order again on the next stump. Ring thickness variability appears completely random to me.

      How can we have confidence in tree rings as an estimate of past temperature, then extend the estimates to a global scale? It’s voodoo science.

      If I had tried to do this in an undergrad science paper, they would have tossed me out on my ear.

      • Wind is why one side of the tree has bigger rings. If you look at prevailing winds, you will note that the rings on the side of the tree which is stretched by the bending of the tree are thinner and more dense. While those on the opposite side of the tree (compressed side) are wider and less dense. This varies a bit with species of tree, but wind has a lot to do with it. Years ago, as a kid, I worked with an arborist (tree specialist). The old man knew his stuff and could tell you how the wind affected large areas by felling a few trees. Trees in the center of a large group would have rings even all the way around while on the edges they would be offset. SO many things affect the tree while it grows that trying to glean temperatures from the rings is a tough sell.

      • “If I had tried to do this in an undergrad science paper, they would have tossed me out on my ear.”

        Not today. In undergrad engineering, maybe, but not in science as currently practiced in academia. Lysenko lives!

    • I’d have to disagree with I agree with Ian also, that rainfall, not temperature, is the most likely factor generating tree-ring widths.

      Tree ring widths are an indicator of growing conditions. All of them put together. For instance, in one year the water could have indeed been low causing ring growth restriction. In another year, water could have been abundant, but the temperature could have been too low for the plant to grow much. Another year, the windows could have kicked up and created dust storms that blocked out sunlight intermittently during the growing seasons, even with adequate water and temperature.

      Biological systems are very rich, very complicated interplays between the organism and the environment the organism is growing in. The only way you can gauge one of these factors is to know all of the others that may have contributed to the organisms’ growth. Assuming a static climate for tree rings with the only variable as temperature is a ridiculously naive.

      Now, don’t get me wrong: Tree rings have value. But they are circumstantial evidence that supports stronger evidence. For instance, if you are looking to see if 18167 (Year without a summer) was global, using tree rings chronologically matched to time would let you know that “something” happened during that growing season. But this can’t be immediately linked to the eruption of Tambora without other evidence, such as temperature readings, correlating ash, and similar.

      • Those poor people in 18,167 AD. I’ve predicted their doom to famine. (Think I can get some money by saying it’ll be caused by climate change?)

        I meant, of course 1816.

      • As mentioned elsewhere, rings within individual trees vary greatly from side to side. Why? Prevailing wind pressure will cause a tree to grow larger/stronger rings on one side. Non-beneficial nematodes or other pests in only part of the roots system. Shade, soil differences, competition from other trees or plants, If you’ve spent time in the woods, especially logging or cutting firewood these things are apparent with minimal opposition.

        In a mixed forest, live oak trees will starve other trees like pines and firs of water and nutrients. Do the smaller rings in the pine trees indicate a declining temperature or a healthy live oak tree? Without access to the original data, including mapping of the trees used for proxies in relation to other growing vegetation or evidence of now dead vegetation, there can be no confidence in tree ring proxies. My experience, and as noted by others, says that water in the growing season is the most critical factor in wild tree growth.

        pbh

      • “Dendroclimatologists” are aware of all these deficits and attempt to offset them by using only certain trees in certain parts of the forest in certain regions. There’s a likelihood that these selections incorporate other unknown errors, and don’t fully compensate for many factors, but yes, the pig does have lipstick.

    • There has been sufficient comment on the ‘hide the decline’ incident to make even the bravest of dendrodisasterologists head for the hills.

      Many other workers have needed to cross train due to their industries failing or as technology makes them redundant, why not them?

      • One could list quite a few new endeavors for dendro retreads, but witch doctors, and the like, are in such low demand today. I’d suggest they take a look at becoming ‘men of the cloth.’ Fustian would be most appropriate.

  7. Two thoughts. No matter how much the data from 710 to 2011 is tortured it represents a virtual zero in the geological time span of Earth’s climate so is fairly meaningless. A bit like saying that if I hiccup twice in succession in a 24 hour period then my life is made up of continuous hiccups.
    The span of the blue area in figures 1 and 3 represent a span of standard deviation between plus and minus 4 or so. Without being a statistical guru, surely that alone tells us that the data is meaningless.

  8. What is the physical or mathematical basis for adding ( or averaging ) std devs?

    If we were measuring rainfall at two sites and added the “normalised” std dev records, what would this represent? What would it tell us about the amount of water?
    Very little I suspect.

    Sadly it seems that the data is only supplied in SD units so it is not possible to profit from the original authors inestimable expertise in converting the proxies to temperature estimations. Maybe some leg work into the original papers could find the actual proxy temperatures.

    I take it that YAM is our old friend the Yamal proxy.

    This looks like a reworking of Mann’s hokey stick. [sic]

    This is just more home-spun, non-validated “innovative” methods with no justification or auditing . Typical dendro-astrology.

  9. Surely we have temperature records which would have been used to calibrate this proxy so it could make temperature predictions before those records began. Meaning that during the calibration period it should either reproduce what we all ready know or prove itself incorrect.

    • calibration is better known as “selecting on the dependent variable”. It is a HUGE statistical NO-NO.

      Google the term. The other soft sciences have finally recognized the problem after it generated tons of faulty conclusions. Which probably explains why it is so popular in Climate Science.

    • consider this. you have a drug test (or a proxy) that is 95% accurate. You have 100 people (trees) in your sample. You test these people and 5 show positive for drugs.

      what are the chances that these 5 people are using drugs? If you didn’t know that these people were drawn from a sample of 100, you would say the chances were pretty good, that you were 95% sure they were using drugs.

      But you would be wrong. Because in a sample of 100 people you would expect to get 5 false positives even if none of the original 100 are taking drugs. The 5 people might be taking drugs, or might not.

      And this is the problem with calibrating tree rings. Unless trees are 100% reliable proxies, then you are going to get a lot of false positives which will throw off your conclusions. And if the trees are 100% reliable, there would be no need to calibrate them in the first place.

      • And unless you have a statistician on your team, you probably wouldn’t even know that, so the authors might claim ignorance.

        Unfortunately, the general public doesn’t know that and it’s counter-intuitive to some extent, so a devious person with a political agenda would have no trouble at all duping them with a paper like this. It’s truly disgusting in my opinion.

      • Unless you blindly build a test which is purely binary in output, false positive come at the expense of false negatives (non detection of a true positive).
        Basic radar signal detection builds on false positive (false alarms) tradeoffs with false positive (missed detection) as gain and detection thresholds are adjusted. Thus if the signal strength is sufficiently above the noise defined threshold to declare a detection, false alarms that degrade confidence in the system are virtually eliminated. This true for any system. If an operator merely gets a binary output, false alarms strongly degrade operator confidence. Sophisticated thieves use this strategy to defeat the human element by systematically inducing false alarms in an alarm system over weeks or months until the operators get tired of false alarms and either turn off the system or ignore alarms.

        So going back to your drug analogy, suppose a hypothetical test can discern 1 ng/mL (+/- 0.1) in a bodily fluid sample. Would it be reasonable to accept any sample at > 1.3 ng/mL as positive? If one decides as a management strategy to avoid the legal implications of a false positive, setting the positive threshold at 2 ng/mL would ensure the positive detection threshold is high to ensure it catches true users. In the world of cycling where doping has always been a problem, two samples are always taken, A and B, so that if A is positive, B can be tested to confirm. If B doesn’t confirm then the result from A must be discarded.

        What you really want is a system that of say 100 true users tested, less than 5 would go undetected. For what you MOST want is a system that deters use. That’s the definition of a 95% detection rate. Not a system that scares 1,000 nonusers by producing 50 false positives (maybe because they ate a poppyseed muffin a day earlier for example).

      • a devious person with a political agenda would have no trouble at all duping them

        Especially if said devious persons already had buy-in from science-illiterate (or politically motivated) media gatekeepers and “science” activists journalists.

      • Joel, I by no means want to take away from your very good example of statistical error and what it means, but I do want to mention that, in this example, I don’t think it’s relevant, only because what’s being done with trees and temperatures isn’t necessarily what’s being done with the testing of blood for the presence or absence of a chemical substance.

        Tree rings are being used as an analog for the thing being tested for, they aren’t a direct measure of it. In the situation you describe (which was based on Ferd’s attempt to explain a statistical artifact, and was valid in that use) there is a direct measure of the thing being detected and there are errors in that measure arising from imprecision of the instruments used. In the tree ring example, we have instrument error coupled with the error introduced when we derive the relation between the thing we’re measuring and the thing we intend to measure, which can be as large as 100%.

        Proxy measures are never accurate, at best they’re representative analogs. In the case of tree rings, they can’t ever be used outside their so called “calibration range”, since they’re entirely dependent on empirical regression models and we can’t ever legitimately use an empirical model outside of its calibration range.

        So while your discussion is very informative from a statistical perspective (and also useful to folks interested in defeating alarm systems), I don’t think it does much to support the use of tree rings to measure temperature before the thermometer was invented.

      • In the case of tree rings, they can’t ever be used outside their so called “calibration range”
        ============
        It is worse than that. Calibration violates the statistical assumption of random sampling. So if you calibrate the tree rings, any subsequent statistical analysis of the rings to see how well they behave as a temperate proxy will be misleading.

        Hidden in the calibrated tree rings are rings that are not responding to temperature at all. Rather they are responding to chance occurrences of other factors, but your calibration exercise gives the FALSE impression that they are responding to temperature. As a result, when you do temperature studies using calibrated tree rings, they are prone to giving FALSE results, because your underlying assumption, that the trees are responding to temperature, is FALSE.

    • Rob, there’s a fundamental problem with the method you propose; we can’t extrapolate from empirical data. In the absence of a well proven and accepted physical model of how tree rings relate to temperature, “calibration” is nothing more than a best fit least squares regression on observed temperature and tree ring width of some period of time. It doesn’t tell you anything at all about that relationship outside the observation period.

      What these people are doing is completely bogus. There is absolutely no reason at all to believe anything they say. The paper is useless. A waste of time. A known lie. Junk. Without any merit.

  10. As usual, clear and easy to follow.

    Then it has been transformed again, this time using the expert judgement of the current authors, into standard deviations based on the mean and standard deviation of the period 1750-1950. Why this exact period? Presumably, expert judgement.

    At a guess, the 1950 cutoff might have to do with the “divergence problem” https://en.wikipedia.org/wiki/Divergence_problem ? The DP being that tree rings purportedly correlate to (apr-sep mean) temperatures up til 1950 and then show temperatures to decline. Seems like they’ve fixed THAT somehow.

    I find this whole thing to be opaque and on the whole I think dendrochronology can indicate which years were good ones for a given tree and which were bad. Can they identify droughts, fires, insect infestations? Probably. But I remain skeptical that they are much good at thermometry.

    • Dendrochronology, the way I learned it way back when, was a method of dating, not a way to determine precise values of growth parameters. The logic behind it is that, in a given area, trees will tend to have good growth years and poor growth years. This can be used to construct a timeline of such years, but only for that area. This timeline can then be used to date certain strata if it is found to contain tree remains that grew during that timeline.
      So yes, dry periods can perhaps be identified by using other information to infer correlations.
      But to jump from that to using the width of the rings to estimate actual rainfall amounts seems more a misplaced leap of faith than science.
      Jumping all the way to global temperatures would likely make that average voodoo practicing, head-shrinking, bones rolling, haruspex shake his head with disbelief.

      • Yes. Dendrochronology in archeology uses trees as a clock, one tree ring tick per year. Very different than pretending treemometers in dendro climatology. Doesn’t work since even at the extremes (tree lines on mountains, boreal forest/tundra lines), many factors influence growth besides temperature, and no tree grows uniformly in a stand.

      • called N-TREND (Northern Hemisphere Tree-Ring Network Development) which brings together dendroclimatologists to identify …

        The authors are not talking about dendrochronology, why are you?

        That is a precise and well established science and has nothing to with dendroclimatologists.

        Some climato-astrologists , like Mann, wilfully use dendrochronology when referring to dendroclimatology because the former has some credibility that they would like to steal

  11. Hi Willis,

    When I read the extracts at BH it raised questions in my mind and I emailed Rob Wilson:

    “I have just read the brief comment on your recent paper at BH and had a quick question from that.

    I understand that you have used the datasets which you considered most robust going back over past centuries. I know from my own experience and observation from growing timber that temperature is just one of a number of factors which influence the rate of growth in trees and thus tree rings. Two simple examples are rainfall and cloud cover. Records of those seem, at best, patchy and generally non-existent for most of the period your study covers.

    My main question is did you, in selecting datasets to use, assess the original studies to be certain that they had taken or were even able to take full account of all of those other factors which I believe have until quite recently been considered largely irrelevant in dendrochronology?

    Are you able to point me towards any work which is able to explain how the growth rate of a tree 500 or 1000 years years ago can determined as being a result of temperature as opposed to rainfall levels, or reduced / increased sunlight from higher / lesser cloud cover, or a change in wind levels (perhaps due to abnormal jet stream positions) causing a degree of stunting / or preventing wind stunting for a year or two, or perhaps a 1 in 100 year flood that deposits nutrients enabling higher growth rates for a period of years thereafter ? The reason I ask is because data on those causes is typically unavailable and if there is a robust methodology for determining this I would be very interested to know and understand it.”

    he kindly replied very promptly :
    “You misunderstand the basics of dendro [climatology].
    All trees are sampled in locations where tree growth is predominantly controlled by summer temperatures.
    The residuals from the local scale modelling may represent “other” factors but are random over space and time When averaging over large regions, the “other” factors are further minimised by averaging

    You cannot expect to get a temperature from a tree that is not growing in a temperature limited location.”

    To which I replied and asked ” many thanks for such a prompt reply which is helpful as I try and get my head around some of this !

    Temperature limited locations controlled by summer temperatures makes sense but is there a way to identify and exclude the other variants of cloud cover and rainfall at that location going back over the last thousand years ?”
    [ I did not say that I actually do not understand how ‘locations controlled by summer temperature’ are determined – but you may have come across this….]

    Rob Wilson again replied promptly :
    “There is some debate about the effects of clouds on photosynthetic rates and a comparison between ring-width/density parameters and carbon isotopes is addressing that situation somewhat.

    Brief take home story is that one of the reasons that ring-width is generally a poor proxy of temperature in this moist-temperature limited environments is that other factors are also impacting growth.

    Density and related parameters are controlled almost entirely by summer temperatures in these environments.

    It is far from perfect, but we state this in the paper – there are good reasons why we don’t explain 100% of the temperature variance.”

    I didn’t have time to pursue this further but did briefly check out a few papers on variations in rates of photosynthesis [PS] related to cloud cover – there have been a number of studies. One using artificial light at times of cloud cover found a 25% increase in PS in the illuminated leaves; conifers may respond differently to deciduous.

    Anyway the above may be of interest.

    • Thanks for posting. Your questions to him are almost too simple and logical. How can you basically use an uncontrolled site with no reference data on other conditions for 500 years and have the balls to say that the only thing that changed was temperature? I will give these guys one thing. They know how to play the game and manipulate the gullible people with the purse strings. Make it ‘sciencey sounding’ and make the graph ramp up at the end and presto! You can afford a new car!

      • Hi Chilemike,
        They seem to prefer to ignore studies which show that leaves are able to alter and maintain optimum temperature of around 21 deg C regardless of the ambient air temperature. (see my replies to Bartleby below).

        Of course that means that the rate of growth, size and density of tree rings has nothing to do with the ambient temperature and so you can’t even hazard a guess at what the temperature might or might not have been from studying tree rings.

      • Hi Bartleby,
        I took the view that if I were critical I would receive no response at all ! But having just searched for “temperature limited locations” which intrigues me, I stumbled across a 2008 science article in the Daily Telegraph and have quoted parts below:

        “The temperature inside a healthy tree leaf is affected much less by outside temperature than originally believed, from England to the Caribbean, according to biologists at the University of Pennsylvania.
        Surveying 39 tree species ranging in location from subtropical to northerly climates, researchers found a nearly constant temperature in tree leaves.

        The conversion of light into chemical energy – photosynthesis – most likely occurs when leaf temperatures are about 21°C, and the outside temperature plays little, if any, role. This means that in colder climates leaf temperatures are elevated and in warmer climates tree leaves cool to keep the temperature just right.

        The research contradicts the longstanding assumption that temperature in a healthy leaf are coupled to ambient air conditions. For decades, scientists studying climate change have measured the oxygen isotope ratio in tree-ring cellulose to determine the ambient temperature and relative humidity of past climates.

        This new work challenges the potential to reconstruct climate through tree-ring isotope analysis, since it suggests the method does not provide direct information about past climate, providing misleadingly warm estimates.”

        From that I take it that the rate of photosynthesis is not dependant on the ambient temperature and so the rate of growth of the tree, and tree ring size and density is decoupled from temperature.

      • From that I take it that the rate of photosynthesis is not dependant on the ambient temperature and so the rate of growth of the tree, and tree ring size and density is decoupled from temperature.

        Thanks very much for that Old England, I didn’t know it but, now you’ve found it, it doesn’t surprise me. I’m one of those unfortunates who entertain the idea natural selection and evolution have played a role in the development of life, and I’ve also heard that temperature plays a significant role in the rate of chemical reactions (this results from an exposure to physical chemistry at an early age), so it makes quite a bit of sense to me that trees would learn to optimize energy production by controlling the temperature of those reactions. I believe the authors are suggesting trees are “warm blooded” :)

        That sort of tosses the idea of using trees to measure temperature; it would be very similar to using a rectal thermometer on a horse to estimate temperature of the surrounding atmosphere. I think another person commenting on this thread suggested that, after removing the effect of CO2 on tree ring metrics, the only remaining signal was annual rainfall, which connects very well with the report you quote. Funny how things start linking up with each other like that isn’t it?

      • Hi again Barleby,

        The researchers aren’t stating that trees are as you say, tongue in cheek, ‘warm blooded’ but that they are able through physical means control the leaf temperature. Below is a link to the article which touches on the mechanisms – apologies I should have put that up with the quotes as it is worth reading.

        http://www.telegraph.co.uk/news/science/science-news/3344206/All-tree-leaves-have-thermostat-that-maintains-temperature.html

        From the limited stuff I have read, and thus limited knowledge I have, there are a few things which strike me:

        From the studies on photosynthesis [PS] rates depending on the amount of sunlight and reduced light from cloud cover it seems that light is a key driver of the rate of PS – but is not necessarily the dominant one as trees are able to moderate and control the PS rate in response to various changes. (artificial light at times of cloud cover increased PS by around 25% compared to adjacent trees at same temp and soil / water conditions).

        It seems from some studies that trees can reduce / increase the rate of PS in lower leaves when higher leaves are at high PS rate in high / low ambient sunlight. Couple that with the ability to control temperature in leaves to maintain them within an ‘optimum range’ (circa 21 deg C) and it begs the question “is there a mechanism by which trees are able to control their rate of growth to optimum levels ?”.

        Given the first two facts it could be part of a Darwininan ‘survival mechanism’ – trees which grow too rapidly produce less dense and thus weaker wood which means the trunk is more likely to snap in high winds and die off. So there appears to be a sound reason for trees to limit PS rates which would result in that happening.

        When plants or trees are grown in a shaded position they grow tall and ‘leggy’ to reach the light – generally with a thin and weak stem – as soon as they have sufficient light available the growth is put into thickening / strengthening the stem / trunk and expanding the canopy with side branches and more leaves. On reaching adequate light the leaf canopy is exposed to wind and requires a stronger trunk. In mature trees they stop height-growth when they reach their normal / optimum level and then extend the side branches and leaf canopy at the same time as thickening the trunk. It seems to make sense that the tree would still need to control PS to avoid over-extending branch growth which would leave it exposed to damage from normal winds – let alone storm conditions.

        Trees grown in windy conditions grow denser trunks, often slanted in response to prevailing winds. Lets assume that a mature forest is subject to a 1 in 100 year storm (as happened in the UK in 1998) and that the bulk of the forest is knocked down. The surviving trees will lay down denser wood for many years after that in response to new exposure to wind until forest regrowth (20-70++ years depending on species) means they are becoming more sheltered again. A dendrochronologist sampling those oldest surviving trees trees 200 or 300 years or more later will conclude that the multi-decade denser wood is as a result of temperature. A complete nonsense.

        CO2 levels are a massive influence on rates of PS – and I suspect this is greater than light levels – because in commercial greenhouses where CO2 levels are highly elevated the rate of PS and growth is significantly increased compared to same plants in same type of greenhouse next door and all other conditions the same but without elevated CO2. (Thus identical sun or artificial light, growing medium, available water and temp to both). We know from NASA satellite studies that the amount of green vegetation globally has increased by ~ 15% in recent years solely due to the small increase in atmospheric CO2.

        We also know that in elevated CO2 levels plants require less water – they obtain higher levels of CO2 for PS with a reduced number of stoma in the leaves and that reduces the transpiration rate and thus the plants water requirements. Hence why deserts are shrinking (acknowledged by NASA, from satellite imagery studies) as plants are able to spread into them despite the limited water available.

        I don’t know if increased CO2 levels produce denser wood and haven’t searched for any studies on that.

        Where sunlight and CO2 levels are the same then as any gardener knows the availibility of water is a key part of determining PS and growth rates – too little or too much (waterlogged) reduce growth.

        All in all I tend to think of ‘dendrochronology’ as more of an aspirational art form than science; creative thinking is the order of the day in the absence of any knowledge on what were the key determinants of rates of tree growth at the time the sample comes from – rainfall, sunlight and cloud cover etc. In the light of trees ability to regulate the temperature of their leaves then the temperature appears to have a minimal effect and cannot begin to be determined from tree rings.

        Btw – always use a thermometer with a large bulb on the end you hold when taking a horse’s temperature – that way you won’t lose it !

      • All in all I tend to think of ‘dendrochronology’ as more of an aspirational art form than science; creative thinking is the order of the day in the absence of any knowledge on what were the key determinants of rates of tree growth at the time the sample comes from – rainfall, sunlight and cloud cover etc.

        I very much like the term “aspirational art” and understand the implied difference with a science. Recently I attempted to make the same distinction on the grounds of it being experimental with repeatable results. I hold that climatology is still in the early throws of being a science and best categorized, as you suggest, an art until further developments take place. Climate may be one of the more complex sciences ever attempted by humans, it’s my personal opinion it’s already demonstrated the limitations of differential calculus and may require a new branch of mathematics to succeed (I kid you not :)

        Btw – always use a thermometer with a large bulb on the end you hold when taking a horse’s temperature – that way you won’t lose it !

        I promise to take that under sincere advisement!

    • Very interesting comments, Old England.
      I have a question which I wonder if you may have some insight into: What sort of trees are they using to construct temperature estimates going back over a thousand years? The top graph shows steady temps over a period that looks to start around AD 700. Is it safe to assume that there are few places where large numbers of living trees of such age exist? Is it therefore safe to think they are using old stumps and such from long dead forests, which may well have had completely different conditions than exist now, even if you did believe that areas could be identified that summer temperature controls tree growth?

      Besides for all that, does anyone think summer temps have good correlation with average annual temp?

      • Hi Menicholas,

        they tend to use a variety of trees from what I can make out. I think the most discredited study was on bristlecone pines which made fairly wild claims based on a minute number of samples.

        The University of Arizona has a Laboratory of Tree Ring research at their School of Earth and Environmental Science. They now run the Aegean Dendrochronology Project which includes tree ring samples dating back “8,000 – 10,000 years”.

  12. Willis Eschenbach:

    Your first diagram shows “Standard Deviations” as its y-axis for the “53 proxies used in Wilson 2016” for the “Northern Hemisphere, 750 to 2011”.

    It is labelled to say “Red line shows annual average of all proxies” but the blue lines are not labelled.

    I am tempted to think the red line is actual values of the average for each year and the blue lines are the standard deviations of the averages shown red. If so, then what are the average values shown in red; e.g. are they annual average temperatures in unstated units? If not, then what are the red and blue indications on the graph?

    I ask for this clarification because I am trying to make sense of the relationship between the two plots. Generally, the red line has ‘high’ value when the blue lines show wide spread, but the spread of blue lines is greatest around ~1300 when the red line shows a rise that is much less than the rise after 1988.

    Richard

  13. Expert = Farmer from the next county but one.
    Professional = Someone who makes a living doing something and sometimes makes a mistake.
    I know which one I listen to.

    And before anyone else says it, the other definition of “Expert” is “Drip under pressure”.

  14. There are 21 proxies in year 2000 and 8 in 2010.
    Visually, the blade sticks up because most of the 8 for 2010 and nearby years point up.
    This small number allows that the pattern has a throw of the dice component, like a string of straight sixes.
    It might be invalid to use the post 2000 data because it is so sparse in relation to the rest.
    Might be interesting to look at the changes in the final graphs after successively holding back these 8 recent ones.
    Likely that the blade would get smaller.
    But that blue mist of individual proxies will still be there, even though some of the higher and lower meet the borders of the graph box before they stop.
    Geoff

    • One thing to do would be to just use the proxies that exist in the end portion. Apples-apples.

      Looks like there’s a bit a ‘plateau’ in there.

  15. Thanks Willis for this article, And I really love this one!
    “Well, it was clear as mud but it covered the ground” ( can I use that one liner?)
    And this ; “Well, you can do it, but the result will have error bars from floor to ceiling” ,
    as graph # 3 shows!

    • Thanks, Tobias. It is a line from a Belafonte song, viz:

      Well it was clear as mud but it covered de groun’
      The con-fu-sion made the brain go round.
      So I went and asked a good frined of mine
      Known to the world as Albert Einstien”

      w.

  16. climate scientists have been very successful in limiting the discussion to temperature although the real issue in AGW is not the temperature but the relationship between fossil fuel emissions and temperature.

    • JM,

      I watched your video, which has no explanation. Then I saw another one (time series), so I watched that, too.

      What are you attempting to show? The videos are both confusing because there’s no explanation or conclusion.

  17. I’ve only skimmed through the original paper but I wonder if there is any correlation between increased tree growth and increased CO2. So far as I can see they don’t seem to have looked at that, although there are an awful lot of links and it is quite possible I missed it.

  18. As usual, there are simply too many ambiguities for me to begin to understand the “Reconstruction Methodology” without going through all the original data myself. The key to clarifying this analysis–and many of Steve McIntyre’s analyses–for those like me who rarely have the inclination to slog through the data is found in this statement:

    I was reminded of a valuable insight by Steve McIntyre, which was that at the end of the day all these different systems for combining proxies are simply setting weights for a weighted average. No matter how complex or simple they are, whether it’s principal components or 37 backwards nests and 17 forwards nests, all they can do is weight different points by different amounts.

    To the extent that the foregoing statement is really true, then a table of the proxy names and weights (for each sub-period over which the weights are used) would slice through all the inscrutable verbiage. (Yes, I know, there are 53 proxies times 55 sub-periods, but a 53 x 55 spreadsheet accompanied by a verbal summary would boil the technique down nicely.)

    Most likely I’ve simply failed to notice that there already are such analyses somewhere in Mr. McIntyre’s or Andrew Montford’s oeuvre. Or maybe some of the methods really aren’t linear weightings after all.

  19. Willis. Another excellent article. Two questions:
    1) What is the global coverage of these proxies? In particular, do any of them cover the oceans (which are 2/3 of the Earth’s surface)?
    2) Accuracy: What are the confidence limits of these proxies? What does the scale on the y-axis of Fig 3 actually represent?
    Thanks,
    Walt.

    • Walt, look at the paper, there is a map showing the locations and some lists giving dates, locations and occurrences.

  20. The Recipe:

    1. Take a bowel of spaghetti.
    2. Feed it into the Hockeystickernator.
    3. Add a dash of “Expert Opinion”
    4. Feed to the press.

  21. Why, oh why do proxy data series never extend to today? Why do they always end 20 to 30 years ago, thus inviting the splicing of thermometer data onto proxy data?

  22. An issue that has bothered me about using tree ring data (beyond the error problem so well covered by Willis) is that even if the growing season is well represented, this is not necessarily average temperature dependent. Cold winter can occur along with warm growing seasons, and cold nights along with warm days (due to clear sky radiation at night). In addition, trees cover only a limited portion of the Earth (not on oceans, or very high latitudes), so this is not a global average. The problem of precipitation level, CO2 effect and others have been mentioned, and probably dominate growth as much or more than daytime temperature. Tree rings are just not a good tool as used.

    • The human species has an innate tendency to be infatuated with its own intellectual infallibility. We believe we can know a lot more than is possible. This self deception has assisted scientists to be misguided for centuries.

      I have nothing but admiration for most the individuals in climate science. However, as a class, they should all take a time out, take a deep breath and reflect on the limitations for understanding the truth. For several decades I have seen “fact-theories” be obliterated by subsequent generations of scientists, who in turn had their findings discredited by successors.

      I’m struck by how many climate scientists who are skeptics have “emeritus” at the end of the title. There might be a reason for this.

      • One of the reasons might be that they have retired and don’t have to toe the company line any more.

      • The human species has an innate tendency to be infatuated with its own intellectual infallibility. We believe we can know a lot more than is possible. This self deception has assisted scientists to be misguided for centuries.

        The internet makes smart people smarter and dumb people dumber.

    • I live in Manitoba, Canada. To say the least, our temperatures are extreme (-35C to +35C). In some years our trees leaf out normally in early May. We often get a “killing frost” following leaf formation. They all die, but the trees re-leaf with fewer and smaller leafs. The rest of the summer/fall doesn’t matter and trees struggle to maintain themselves until fall. How would this show up in the tree rings?

      • I’m pretty sure that’s a microaggression, although you’d have to find other trees with altered rings.

  23. I think you are basically right.

    One observation is that none of the authors is explicitly a statistician (although one can’t tell which departments some of the authors are in).

    One can process data as much as one likes but lousy data will only reveal so much.

    I thought that tree growth depended on how much local water, CO2 and nutrients were available as well as temperature. I have always been astonished by the claim that temperature several hundred years ago can be measured from tree rings.

    Also I don’t like using part of the record being used as a baseline for normalisation. Shades of Mann – at least they didn’t use PCA

    • Indeed one of the CRU emails leaked was written to one of the team (Jones I believe, but I might be mistaken after 5 years) by an expert on tree growth to explain why tree rings are a poor proxy for temperature, and the entire root (pardon the pun) of the decline hidden by “Mike’s Nature trick” was the divergence between tree-ring proxy temperature trends and measured temperature trends.

      • Ed Cook, considered by many n the field to be the foremost expert on dendro, basically said we know nothing about climate variability greater than 100 years ago (his words in the CRU emails were “we know fu** all”) So I’d like to know where the magic knowledge suddenly came from, and if there is no new knowledge, where is Ed Cook’s refutation of this sort of thing?

  24. We lost a large white oak in a wind storm a few years ago. Right after the tree was cut up ready for removal, I took my kids out to count the rings. 178 of them. It was also amazing how tightly packed the rings were right up until 1927. After that, they were much more widely spaced apart.

    According to historical pictures of the area, the tree was one of many in a densely packed forest until the lot was cleared to build the original house on the lot.. in 1927.

  25. before looking at the data, the question to be asked is “how were the proxies chosen”. were they a random sample, or was some criteria used to filter the samples?

    because if the samples were not chosen at random, then what is the justification for using statistical methods on the data?

    the second question is, what evidence is there that the samples are actually reliable proxies for temperature?

  26. So to summarize the contention of those who we are told are not in d-nial – we should place total faith in this pile of inferred and speculative sludge whilst regarding the modern satellite data set with great skepticism and suspicion.
    And, furthermore – we should not query that the field of dendrochronology appears to have vanquished its own concerns with the observation that their methodology, when consistently applied, fails to replicate late 20th century warming.
    We should disregard that they themselves accept that the same methodology that irons out known climate trends during the last 1000 years also tells us that the climate cooled during the late 20th century.
    That is – if we take the results as valid, or useful, or in any way indicative of something that reflects reality.
    Reality – remember that place?
    The place where we all actually live.
    Then again, who needs reality? It is an annoying place and should ideally be eliminated promptly.
    And as we are now informed, by satellite expert Michael Mann, satellites can not be trusted.
    We should place our faith in the mystical interpretation of tree-rings and premium cocoa beans, as hand selected, then carefully blended by the high church of self-proclaimed expert master chocolatiers.
    Following the lead of Mann and Trenberth, I have now completely lost my faith in satellite technology and now I am unable to trust even the information provided by the GPS in my car.
    So, it tells me that I at a junction.
    And I may indeed appear to be at that very junction, but how can I know that my satellite based GPS is not lying to me?
    How long must we wait before Michael Mann and his church of tea leaf interpreters will construct an alternative Global Positioning System that is based upon a network of location sensitive trees?
    I, for one, will be the first to adopt such an alternative.
    Nothing can be more irritating than to start out on a journey from the first millennium and then discover that only a few hundred years down the road you are caught up in a medieval warming and then a nasty little ice age.
    Especially when you later discover that you could have taken a direct route all the way to the 19th century without the unnecessary diversions.
    I have also lost my trust in the mars rover.
    I suspect that it is not really on mars at all.
    It looks to me like it may have landed in Arizona. (erm…may contain sarc).

    • My dad uses location sensitive trees to navigate his land in Northern Minnesota. He simply uses a ferrite rod to integrate Poynting vectors into the trees. The vectors are spacially integrated into the trees based on the digital location of the sun relative to sunrise or sunset. He never gets lost now.

      • Yes, I’m working on this tree.p.s. idea.
        So far, I’ve managed to engrave the words “you are here” onto a piece of spruce.
        It’s a start… :)

  27. Willis has uncovered a number of issues of concern with the N-Trends reconstruction and as a number of commenters have pointed out tree ring data is not in any way suitable for estimating temperatures to any great accuracy – though I do think it can be an indicator of “favourable” and/or “non-favourable” climatic conditions.

    That said, it occurs to me that the reconstruction is not exactly devastating to the sceptics argument. First, There are 2 good reasons why we can ignore the post-2000 spike.

    1. The number of proxies available is considerably smaller after 2000.
    2. There is no comparable spike in the measured observations over this period (not even in GISS).

    Having had a quick look at the paper, it seems the study finds a clear MWP, a LIA of around 500 years during which temperatures were about 1 degree cooler than the MWP and a modern warm period in which temperatures have returned to MWP levels

    The warmest non-overlapping decades cited in the paper with anomalies (relative to 1961-1990) were as follows:

    1994-2003 0.34 +/- 0.25
    1946-1955 0.30 +/- 0.19
    1161-1170 0.27 +/- 0.23

    I wouldn’t be in too much of a hurry to debunk this paper.

    • “as a number of commenters have pointed out tree ring data is not in any way suitable for estimating temperatures to any great accuracy ”

      You just debunked the paper John. This nonsense should never have been published.

      • You just debunked the paper John. This nonsense should never have been published.

        I think you’re wrong – because we are not using the reconstruction to estimate temperatures. Providing it’s limitations are made clear, the study COULD be useful in providing a general broad brush reconstruction of NH climate change over the past 1000 years or so.

        I don’t believe for one minute that you can legitimately compare an annual proxy temperature anomaly with an annual thermometer anomaly nor do I think that the proxies capture the true range of temperature variability, but it’s possible they capture the timing of climate shifts and the RELATIVE magnitude of those changes.

        If you ignore the post-2000 spike, the reconstruction isn’t that much different to what a lot of researchers who are sceptical of CAGW believe.

      • John..
        So you think the tree thermometers are good because the results confirm your beliefs? The 1994 to 2003 result surely is bogus because of the CO2 issue. To a lesser extent, 1946-1955. How about using a correction factor based upon CO2 levels and do your post again.

      • John, I’m afraid I find the entire idea of trying to use tree rings to measure temperature intellectually offensive. It bothers me quite a bit that people who advance nonsense like this are considered scientists.

        No, I don’t think this method is useful as either a relative or absolute measure of temperature. It’s been pointed out over and over that tree growth is influenced by many factors that experience large variation on an annual basis. It might have been an interesting hypothesis at one point, now it’s simply annoying.

      • John, I’m afraid I find the entire idea of trying to use tree rings to measure temperature intellectually offensive.

        Did you not read what I wrote?

        I clearly said that you cannot estimate temperature using tree rings to any real accuracy nor can you use it compare temperature with thermometer measurements, but it is (or might be) possible to make a relative comparison – providing a consistent method is used over the entire period.

        I’ve no idea whether an anomaly of 0.34 deg for 1994-2003 above 1961-90 baseline is valid or not – BUT IT DOESN’T MATTER. What does matter is how the anomaly for that decade compares with the anomalies for other decades.

        Let me give you a simple example to illustrate my point. Imagine we have a lake and we want to measure the water level to find out if it rising or falling or neither. Each year we take regular measurements and record them over several years. We might also calculate the depth of water in the lake which might be based an initial survey.

        Now imagine someone comes along and discovers that the lake is actually much, much deeper than we thought and the depth of the lake is actually twice what we thought it was.

        Our measurements of the lake depth are completely inaccurate – but that doesn’t invalidate the lake level measurements because they are based on relative values. We can still provide an estimate for the change in level. It doesn’t actually matter that we have no idea how deep the lake is – just as it doesn’t matter what the actual temperatures are when comparing “temperatures” in the reconstruction.

      • Did you not read what I wrote?

        I believe I both read and understood what you wrote. I’d ask you the same question but I’m almost certain you both read and understood my reply. It was very concise and it’s been made by many others. In essence:

        It’s been pointed out over and over that tree growth is influenced by many factors that experience large variation on an annual basis.

        I clearly said that you cannot estimate temperature using tree rings to any real accuracy

        I believe I clearly agreed with that statement, if not I’ll do so here. I went further to say I (and you AFAIK) can’t estimate temperature from tree rings at all.

        I’ve no idea whether an anomaly of 0.34 deg for 1994-2003…

        Neither to I. I’d again go further to say I have no confidence any proxy measure known to humans can even approach a precision of 1/100th of a degree. The entire idea is silly and has no scientific basis.

        Let me give you a simple example to illustrate my point.

        So, your example demonstrates that using a measure of surface height is useless as a measure of depth? My point was that tree ring width is useless as a measure of temperature. There was never any reason at all to take a surface level measurement as a depth measurement. It’s a very clear representation of pure stupidity. I fail to see how this analogy of yours advances the argument that tree rings are, in any way at all, a useful measure of atmospheric temperature, frankly I believe you’ve just illustrated my point rather well.

      • It’s been pointed out over and over that tree growth is influenced by many factors that experience large variation on an annual basis.

        Quite – but one of those factors is temperature. So – while you cannot infer temperature FROM tree ring growth it might be possible (with sufficient observations) to deduce the contribution of temperature TO tree ring growth.

        Your points about the precision of the anomaly are irrelevant. The anomaly might be 1.34 degrees – in which case the anomaly for 1946-55 would be 1.30 degrees and for 1161-70 would be 1.27 degrees. It doesn’t matter. Just as it doesn’t matter if the depth of the lake is 10m in Year 1 and 10.01m in Year 2 or 20m in year 1 and 20.01m in Year 2. The level of the lake is 1 cm higher in Year 2 than it was in Year 1.

        The anomaly is effectively an index. It is a relative value. I don’t particularly care whether it’s realistic or not. I simply want to know if it provides a reasonable comparison with other decade long periods. e.g. Is it reasonable to conclude that NH temperatures in 1946-1955 were broadly similar to those in 1994-2003 – and in 1161-1170 for that matter.

        The researchers have been totally fair and unbiased (apart from the inclusion of post 2000 data). Their method may be flawed but if it is then it’s equally flawed for the entire series.

      • While we can’t deduce the temperature from tree ring growth, there’s reason to believe we can deduce the contribution temperature made to tree ring growth (again within a range) – which is not quite the same thing.

        John I think it’s safe to conclude that trees don’t grow under the cover of ice. We have a fair amount of evidence that would support a true theoretical relationship between the presence of ice and the growth of trees. Frozen trees don’t grow, I’m virtually certain that’s true. I’m also certain trees don’t grow in temperatures exceeding 260 degrees C (500 degrees F). I haven’t formalized this into a physical model, but I’m sure one could be developed and that it would prove predictive.

        That’s a level of precision I can accept

        It’s not even quite as simple as that. Trees don’t grow in the Sahara but do grow quite readily in the Malaysian rain forest where the mean global temperatures are roughly similar to the Sahara.

        Clearly we need to make certain assumptions. e.g. there was no local desertification or an anomalous tropical type rainfall. Some years will be drier some wetter – but with enough observations those factors will be “smoothed out”.

        Is it reasonable to assume that tree growth was greater in the MWP than it was in the LIA?
        Is it reasonable to assume that a long term warming trend (e.g. 50-100 years) will result in generally more tree growth over that time (not every year – but generally)?

        IF so then look at this study with that view, Don’t get bogged down with the detail of the exact measurements or the precision of the anomalies.

      • There is a paper from (1976 I believe) that examines the isotopic uptake that does correlate with temperature rather than just the width of the trees, which is not scientific at all. The isotopic record is very accurate all the way back to 910 ce. The record does go further back further , however there is a break going back before 910 ce and some uncertainty. Various long lived trees worldwide are consistent with one another. This record clearly shows both cooling and warmer periods in contradicting AGW rather than local events as the IPCC maintains.
        Width of tree rings related to temperatures can be imprecise. A wetter cooler summer can produce a greater width than a hot dry one. Altitude for same species trees, soil conditions ( which causes differential in coloring, growth) , other competing trees which can stunt either by shade or chemical release, side of the hill, extent of range… all effect the width.
        This particular issue truly pushed me over into the camp of being a critic of AGW. The published results and the resulting peer review support along with academic approval meant that they didn’t have any idea about the subject or were lying (and knew they were lying) to promote a cause.

        If they are going to promote a cause based made up reasons, I’ll take up a new field, like astrology, I’d probably be pretty good at it.

      • rishrac writes: “This particular issue truly pushed me over into the camp of being a critic of AGW.” (while discussing opinions on the tree ring metric).

        It’s odd you’d say this, it was exactly this issue that caused me to dig into Mann’s ’98 paper. I found it completely absurd he would assert the precision he did, or that he’d use a metric so obviously confounded with multiple variables. It said, more strongly and convincingly than any other part of his work, that he was either stone cold stupid, or a bought and paid for shill serving a political agenda.

        At the time it was shocking. That he would do something so obviously and completely wrong astounded me. That anyone would take his work as serious science was offensive. At that point, right then, I lost any and all confidence in the IPCC, Michael Mann, an the AGW hypothesis.

      • Bartleby,

        Looks like you and rishrac are on the same page.

        I agree that treemometers are nonsense. There are many variables that make a bigger difference, like CO2:

        That was sorted by CO2. This one’s sorted by temperature:

        Tree rings are the outliers when compared with much more reliable proxies:

      • A recent poster recommended a book called Hubris. I’m about a third through and it’s a pretty good read.
        Dissects the field of broader field of science and identifies roots of some of the problems including the leaps made by some scientists to parlay their narrow field of knowledge into rock star opinion on other issues. Also discusses the self fulfilling peer review process and how academia’s publish or perish demands have created a mosh pit of unverified/unreplicated findings that hold very little value. Lots more to the book that makes you go hmmm.

        I haven’t gotten to the solution part but the book is steering towards an expansion of the trust but verify mindset (replicability) with a dash of smackdown concerning the appeal to “only experts in the field” can weigh in on the worthiness of a fact.

    • ECB January 16, 2016 at 9:49 am
      John..
      So you think the tree thermometers are good because the results confirm your beliefs?

      I never said that – though they do go some way to supporting those who believe there was a MWP and LIA.

      Tree rings cannot measure temperature. I KNOW THIS. However temperature does contribute to tree growth (within a range of temperatures).

      While we can’t deduce the temperature from tree ring growth, there’s reason to believe we can deduce the contribution temperature made to tree ring growth (again within a range) – which is not quite the same thing.

      This study uses the one method for producing the reconstruction. It doesn’t use tree ring proxies for early periods and thermometer record for the later years. It is comparing like with like. The variability may be flat but it’s the same for all years. It’s a relative issue – not an absolute one.

      The study essentially says nothing more than this: the MWP was about 1 degree warmer than the LIA and the modern warm period was about the same as the MWP.

      • While we can’t deduce the temperature from tree ring growth, there’s reason to believe we can deduce the contribution temperature made to tree ring growth (again within a range) – which is not quite the same thing.

        John I think it’s safe to conclude that trees don’t grow under the cover of ice. We have a fair amount of evidence that would support a true theoretical relationship between the presence of ice and the growth of trees. Frozen trees don’t grow, I’m virtually certain that’s true. I’m also certain trees don’t grow in temperatures exceeding 260 degrees C (500 degrees F). I haven’t formalized this into a physical model, but I’m sure one could be developed and that it would prove predictive.

        That’s a level of precision I can accept.

      • John Finn, you say that although we cannot measure absolute temperature with tree rings, we can measure relative temperature using tree rings. There are a couple of problems with your plan.

        The first problem with this idea is that both high temperatures and low temperatures cause narrow tree rings. As a result, the central assumption of treemometry is simply not true. This assumption is the incorrect idea that there is a linear (or basically linear) relationship between tree ring width and temperature.

        The second problem is that growth is not a function of temperature alone, but (to a first approximation) a function of temperature, moisture, wind, insolation, crowding, disease, and insect infestation. Disambiguating temperature from that whole mix is not an easy or simple task.

        As a result, when you say:

        The study essentially says nothing more than this: the MWP was about 1 degree warmer than the LIA and the modern warm period was about the same as the MWP.

        … I’m afraid that statement is not supported by the data, even if the analysis were done properly.

        Unfortunately, the what they they have done it is not only not proper, it is bizarre. They take a bunch of proxy-estimated temperatures, normalize them to the period 1750-1950, average them, and convert them back to temperatures using linear regression.

        I know of absolutely no theoretical justification for such a procedure.

        w.

      • Willis

        The second problem is that growth is not a function of temperature alone, but (to a first approximation) a function of temperature, moisture, wind, insolation, crowding, disease, and insect infestation. Disambiguating temperature from that whole mix is not an easy or simple task.

        Rather, “The second problem is that growth is not a function of temperature alone, but (to a first approximation) a function of temperature, moisture, wind, insolation, crowding, disease, insect infestation, AND CO2 levels at the time. Disambiguating temperature from that whole mix is not an easy or simple task.”

        The very rapid “growth” seen in tree rings post 1950 is far easier to ascribe to the continuing, ever-increasing CO2 levels from some 280 (1850 guesstimate) to 350 to today’s 400 ppm) that definitely cause a 12% to 27% increase in ALL plant growth,; than to the staggered, intermittent jumps and drops in recorded temperatures of 1/4 of one degree that “might” be related partially to temperature changes.

        Prior to 1850? You “might” be able to claim that CO2 was constant w/r growth rates.
        After 1850? That claim cannot be made at all, but Mann does not want to allow for ANY possible benefit of increasing CO2 in the atmosphere – it would be bad for his business, his industry of getting funds and publicity and power.

      • RA Cooke,
        I had not ever thought of this prior to reading through the comments on this thread, but as soon as one thinks about it, the obviousness of what you say is…um…very obvious.
        We KNOW that CO2 concentration relates to growth of most plants and trees, and higher amounts allow faster growth, assuming CO2 is the least limiting factor. Which is often is. More than often…almost always.

      • Willis

        The first problem with this idea is that both high temperatures and low temperatures cause narrow tree rings.

        Indeed. The tree ring growth response to temperature is reckoned to be an upside down U shape, i.e. there is an optimal temperature after which tree ring growth is stunted. Fine – I know all this. However I also know that the temperature range for most regions over the past several centuries is unlikely to be much outside +/- 1 degree. Now it’s possible that the upper range of temperatures has pushed tree growth over the hump in *some* regions but is that going to happen right across the NH at exactly the same period in time.

        The evidence suggests not. In general, ring widths are wider in the MWP and the modern period than during the LIA years.

        We also know that crop failure and famine were more common in the LIA years – i.e. the years identified by the Wilson study as being cooler than the MWP or recent years. Now that could be because of widespread heat and drought in the NH but I somehow doubt it.

        Providing we understand the limitations of this study I don’t think it’s entirely useless.

        I don’t think the findings that the mid-12th century was about a degree or so warmer than the early 19th century is totally unbelievable.

  28. Many thanks, once again, for a great post, Willis.

    Yesterday, the local weather forecast for my region (Liverpool, England) was: “sunny, clear skies (day and night), with a max temp of 4 deg C and humidity from 75-77%. Today, the “forecast” for the same period is: cloudy and raining throughout, with same max temp and humidity at 95%. Presently, outside my home, its snowing!

  29. “This strikes me as … well … a strangely circuitous route.”

    Willis, you’ve certainly proven yourself a master of understatement.

    After quite a long time building and using metrics myself, I have to say the entire endeavor surrounding temperature proxies based on tree rings is laughable. Any attempt to improve them are doomed; the base data is confounded in so many ways (water, CO2, etc.) it will never resolve to a measure precise +/- 5C, and that level of precision would be truly astonishing.

    I’m pretty sure this won’t stop the folks feeding at the government research trough from continuing to “attempt” it, but I am certain they’ll never succeed. The real problem is we have folks like the NSF who’re either too stupid or too corrupt to de-fund this nonsense. As long as this situation persists, there won’t be any hope coming and the general public will continue to be bilked by these charlatans. It’s an egregious corruption of science and we, as scientists, have very clearly abandoned our duty to self-regulate.

  30. If they had a sound scientific background it should have been beaten into these “scientists” that every stage of data processing of any sort increases the size of error bars. If not they are not scientists, if so where are the error bars and what is the calculation of these increasing errors.

    I am giving you, Mr Eschenbach, more credit than the paper’s authors in assuming you did not simply ignore some deep discussion thereof in the paper, knowing its relevance to this article. Given the normal reluctance of alarmists and enthusiasm of sceptics for considering errors and given the normal dishonesty of alarmists and honesty of Mr Watts’s invited contributors I believe this is justified by the time saved in wading through a paper I am ill-suited to analyse in depth, but anyone is free to correct me if I am wrong.

    • If they had a sound scientific background it should have been beaten into these “scientists” that every stage of data processing of any sort increases the size of error bars. If not they are not scientists

      Live and learn. Evidently, the term “scientist” is not just the guy slaving away at mundane, replicable experiment and observation but instead has been expanded into broader vocations such as modelers and those that make a living from extrapolating those observations. The book I’m reading mentions that up to 27000 articles a week (Van Noorden 2011) are published in some peer review publication each week. Surely, most of that is not based on new conclusions that move the ball of knowledge up the hill.

  31. Willis,

    While I don’t know what qualifications an expert in dendroclimatology has, these are pre-screened datasets. If you had an actual average of the original data you would very likely have a flat line with no blade whatsoever. In addition, very few trees exhibit correlation with temperature in any way.

    Mann’s large 2008 series data (1109 series) showed no statistically significant signal on unmanipulated raw data. The opposite of what the paper claimed. So he used someone elses spliced-with-temperature tree data Luterbacher, to infill the rest of his series using PCA processes. Some of those series, he famously truncated to remove the decline.

  32. The more they try the clearer it becomes to this layman that the only sure way to get temperature from a tree ring is with a match.

  33. Where else in history of mankind, has sloppy work given people doing it the right to criticize how it’s revealed? Wack-0-Dynamics of cold, light blocking fluid baths, converting to heaters, massive numbers of self referencing papers, arrogant claims to have not been proven wrong when thermodynamics as taught CHILDREN are one of the PRIME tools against the Church of the Magic Sky Heater.

    When an entire industry of various fakes, posers, and self referenced experts tell a whole planet: a whole planet,

    that a cold, light blocking bath,
    reducing energy to the surface of an object,
    the reduced energy to be distributed and emitted from an overall COLDER, LARGER MASS:

    that’s the definition of c o o l i n g.
    The definigion of COOLING an object is ”reducing energy to it” the ”distributing and emitting that through an overall larger, colder mass” is practically the definition of cooling, verbatim.

    Instead, to the thermometer analysis FAIL crowd – that spells heater in the sky. Ya’LL.

    It’s unbelievable what a bunch of government employees can encourage in destruction of scientific discourse.

    Ever see a single one of these Magic Gassers start discussing the atmosphere as a cold, light blocking, turbulent, self refrigerating, compressible fluid bath? Of COURSE not.

    Know why? Any reference to calculating atmospheric energy values properly IMMEDIATELY draws people remarking how verified instrument data from Venus and Mars, correlate to standard atmospheric calculations perfectly.

    And, if those gas calculations project Mars and Venus’ temperature correctly then the identical calculations – in the law written TO calculate atmospheric energy – MUST by extension work for earth.

    The climatology field is overflowing with incompetents who have never had to be right or be fired in their lives.
    This gives them the idea their shouting and tantruming at real scientists – people who analyze the planet and atmosphere like what they are: a sun warmed object and reflective, cold compressible fluid bath – is some kind of ‘victory’ for scientific clarity. It’s repugnant.

    Here’s an example of what happens when you take a Magic Gasser’s word for – well, anything.

    Without an atmosphere of course 100% sunlight reaches the surface for that distance.
    When counting stepping through thermodynamic process, the first thing observed regarding presence of an atmosphere is – oxygen scattering. This makes the blue sky overhead. Simultaneously to this is infrared scattering in shortwave and in longwave by the Green House Gases.
    With several PPM Green House Gases in the atmosphere, there’s energy loss and scattering. Initially when you add some you have 1% loss.
    Then when you add more GHGs you scatter/absorb more atmospheric energy in – infrared – til 10% energy is lost.
    As you add more and more GHGs you BLOCK more and more energy in creating more LOSSES. Cooling.

    As you reach enough suspended GHGs to block 20% energy to the planet – what you have now – that is amplification of
    Green House Gas scattering losses. Cooling.

    You can go look it up if magic gassers haven’t made it so difficult you have to sort the numbers manually; but – in ANY case – no MATTER what – there comes a point where – additional GHGs are going to BLOCK
    more than 20% energy to the planetary surface. Further cooling.

    However when you ask Wack-0-Dynamics incompetents, – this is magical green house gas ‘warming.’

    With the entire story adding up for ALL who believe and bark it like it’s honey to their intellectual bee hive,

    that there’s a rotating sun warmed rock.
    it has appended to it a cold, turbulent, gas bath, that stops 17-20% of the energy from the sun ever arriving.
    This REDUCED energy load is then

    distributed and emitted through an overall LARGER, COLDER, total mass. This – again – is practically the definition of c o o l i n g something.

    But because ”you don’t have the right friends,” phDs and various quack-tards who RUN – given the opportunity to analyze a thermometer and simply show everyone – they can COUNT – claim there’s a ‘fringe’ out there who ‘don’t admit the basic science is sound.’

    This from the church which swore in print GHG emitted light was warming oceans till a REAL scientist, blogger Konrad, posted the experiment named [ Konrad: Empirical test of ocean cooling and back radiation”] that remained online, slapping these lower primates in the face for 4 YEARS: till finally,

    run ragged at their scientists admitting they’d faked records for 12 years [FEB 2010 BBC Phil Jones Interview]

    having every single one of their apologists mocked to shame for their utterly incompetent thermodynamics claims, finally one Green House Gas Effect apologist broke and admitted their pseudo-science isn’t above experimentation,

    *like they had claimed multiple times to escape facing the fraudulence of their Magic Heater claims*

    And Roy Bates did the experiment showing clearly: just as had been reported in papers for decades, the chilled skin effect of water facing GHG emitted light, is enhanced past the surface chilling of evaporation only. GHG emitted light, striking liquid GHG water – SURPRISE – when striking liquid water, hastens evaporation: leading to MICRO CHILLING of the first few surface molecules and hence the entire body.

    [Can Infrared Radiation Warm A Water Body?] Spencer’s experiment was a SECOND one done showing clearly that water exposed to the light emitted from GHGs doesn’t WARM due to it. It COOLS due to it.

    The light comes primarily from water, as a gas. Go FIGURE it tends to entangle with the first water molecules it hits, and reverts that liquid water to – gas.

    Have you seen the Magic Heater church putting up the news that people discovered you can easily check the validity of standard gas equations with probe instrument readings from Venus and Mars ?

    Have you seen them TELLING YOU: that – Oh, it looks like 70+ PERCENT of the earth is CHILLED by GHG back radiation?
    Note that – this is simply a matter of the size of liquid water molecules. This goes for DEW, for RAIN, for FOG that SETTLES on surfaces – it it’s liquid water, the light from GHGs reverts what it entangles with to gas. And what it doesn’t entangle with it simply rebounds away from. Liquid water’s opaque to LW GHG emitted light.

    These people aren’t capable of analyzing a thermometer and all you have to do is tell them – ”analyze this sun warmed rock, immersed and scrubbed and blocked by this frigid, light blocking fluid bath.”

    They won’t. Because they know if they do, at the END, they have to say ”and that is how I think a reflective atmosphere reducing energy to a sun warmed object 20% –
    then distributing that REDUCED energy load to be emitted through a LARGER, COLDER MASS: is a heater.
    Ya’LL.

    Because the definition of reducing energy to something 17%, is reduction in energy density. And that’s a definition of cooling.

    And the distribution and emission of that REDUCED energy load through an overall LARGER COLDER MASS: the combined earth/atmosphere radiation surface –
    is AGAIN: cooling.

    And it doesn’t matter how many years it takes, the various frauds and posers who thought they’d simply choke out scientific reality with massive doses of stupid combined with character assassination and acting like psychopaths – faking data – which of the HASN’T BEEN CAUGHT faking data?
    Hansen
    Mann
    Jones
    Briffa
    Trenberth
    Tom Wigley,
    and a host of smaller less significant frauds in the mathematical/physics ‘weather research’ arm of government – There are very FEW who HAVEN’T been CAUGHT FRAUDULENTLY FAKING ”research” about ”ODD GOINGS’ ON with the TEMPERATURE.”

    Jones admitted: they’ve been faking every record they issued since 1998. Met Office in 2013 released their OWN OVERALL admission temperatures were ”relatively flat” – no warming, slight cooling as Jones admitted- twice – with the press release ”The Recent Pause In Warming”

    Where they remark they’ve written three papers about the ”pause over the past fifteen years to 1998”.

    It’s fraud. If it weren’t, every single site run by every single believer, would be a SHIMMERING SEA of CRYSTAL clear atmospheric energy, thermodynamics. Instead EVERY SITE OWNED by a believer is an OCEAN of CLICKBAIT, SHABBY, F.U.D.

    FEAR you’re going to find out how FAKE it all is

    UNCERTAINTY how to keep everyone listening to endless talk of their scientifically worthless vomit
    DOUBT that anything can help except more of their lying, and more mass communications spam of endless, shiny, colorful, click-bait bullsh**.

    If you really thought the ”pot’s like heroin” scientific scam by government employees the past 80 years has been fun,

    you’re going to love the people who can’t analyze a thermometer told the answer ahead of time, taxing you and ruining your, and your childrens’ names, because they don’t agree to the Magical Heater too big to deny,
    but too small for it to have any real effect you can measure. Like that insolent incompetent fraud Gavin Schmidt said about the non existent atmospheric warming: ”It’s almost like it is there if you look at it long enough.”

    • Abe,

      I have read several of your comments over the past couple months, and I am unclear/confused about what you are claiming “bottom-line” if you will, about the overall effect of atmosphere on planet temps. Could you please indicate (in a rough way) what you believe would be observed (particularly in terms of general temps) if;

      The Earth had half it’s actual atmosphere

      The Earth had twice it’s actual atmosphere

      • I think Abe is generally speaking of a subject which is requested by our host not to be discussed…that CO2 cools the atmosphere…it does not warm it. This is also called the sky dragon theory or something like that.

      • Menicholas,

        I’m asking what Abe believes would be observed, if the Earth had half/twice it’s actual atmosphere. He’s obviously allowed to express his opinions about such things, and I simply want to get a better grasp of what his perspective/approach entails . .

  34. Thanks, Wilis. GIGO, no matter what the process is; trees are good CO2 sinks, bad thermometers.
    Paraphrasing Simon and Garfunkel:
    After changes upon changes we dendrocrinologists are more or less the same.

  35. Willis, you said, “Without seeing the underlying data, it is hard to judge the full effects of what they have done.” Let me clear that up for you.

    The author data-mined previous granted studies he had done, probably applied for another grant to study this same data he had previously received grants on, and squeezed it to see if he could get gravy (money) out of it. Sure enough, gravy came out. The gravy train just keeps on trucking. Clever researchers. They have figured out a way to game the system.

    Original research is so passe’ under post-normal science. However, the taxpayer is left with mumbo jumbo jargon in grant applications without realizing they are not funding original research. It is now more lucrative, and expensive for taxpayers, to re-wash been-there-done-that data than to get grants for original research.

    • Hi Pamela: Richard from Canada here. I couldn’t agree more. During my career I wouldn’t have thought about trying to publish an article that didn’t contain new and original data. The publish or perish axiom has indeed taken over, much to the detriment of science.

  36. @willis

    why on earth would they convert it out of degrees C again, and then at the end of the day convert it back into degrees C? What is the gain in that?

    The converted degrees C represent a normalized value with zero mean and unit variance, so it’s really a measure of temperature anomaly, not absolute temperature.

    But I assume the original values were also estimated temperature anomalies, which per se are more “accurate” than absolute values, in the sense that they are immune to calibration shifts and biases (provided the underlying proxy model is roughly linear in the support region). So not clear what is the “gain” in doing that.

    Perhaps there are random errors in the each of the proxy-generated temperature step sizes such that they are no longer the same “units”. So normalizing to z-scores might help, assuming the data are all identically distributed. But that assumption seems unlikely because of the different underlying proxy mechanisms.

    A more likely reason for using standard deviations might be to create the illusion of extremely high statistical significance. Looking at your Figure 2 plot one can see that the “hockey-blade” corresponds to a normalized value of “3-sigma”, which automatically suggests a confidence interval of 99.7% in the usual statistical interpretation of a normal distribution.

    But this is not data drawn from a single, simple normal distribution of values. In fact it is a series of distributions which are not stationary, the mean and variance are a function of time. Also the sample density decreases significantly for the blade region values. Sampling confidence usually does not increase with decreasing sample density.

    So this unit conversion could be just eye candy to impress its targeted lay-audience. But let’s reserve judgment until after reading the full paper.

  37. Here’s a sample display from the Mesa Verde National Park museum. This picture was taken last summer.

    This sample placard harkens back to a time when tree rings were not used as univariate temperature gauges.

    Note that the stenciling of this placard (Variability of Annual Ring), dates it to before personal computers and printers now are used by sample curators to produce these kinds of display placards. This placard is at least pre-1980, over 35 years ago, before the rise of a fraudulent use of tree rings as temperature gauges was driven by the rent-seeking that the Global Warming scam fueled.

  38. I thought that using tree-ring data to estimate palaeo-temperature had been thoroughly debunked by now, but here we go again.

    What I fail to grasp is how anyone can even THINK you could create temperature records from tree rings alone. I mean it’s obvious (and has been repeatedly brought up in this thread) that tree growth is the resultant of many environmental variables. So how can you isolate the one variable you want to study (i.e. temperature) when you don’t have independent evidence of what all the other variables were doing over the same time sequence, in the same general areas where your tree samples come from?

    Until someone can explain this in words that make sense, it seems appropriate to totally ignore this tree-ring circus.

    =============================

    Here’s what I would do if I had the inclination and the resources to do it (and grad students to do the legwork). Take a few well-studied forests over a well-documented time span (e.g. the 20th century). Then try to isolate a species whose growth responds more to temperature than rainfall, and another species that responds more to rainfall, and another species that responds more to sunlight/cloud cover, and another that responds more to length of growing season (which is only loosely linked to temperature). And so on and so on. Then you would have the tools to tease palaeo-temperatures out of multi-species tree ring sequences in similar forests in historic times. Because you would have multiple parameters to play with and you could use fancy polyvariate statistics to isolate the independent variable you want to look at.

    Maybe it’s possible, maybe it’s not. Perhaps all the trees in a forest respond more or less similarly to environmental changes (that, to a casual observer, seems quite likely to be the case, in which case your study was a bit of a time-waster). But that’s the SORT of approach that a SCIENTIST (which I’m reasonably sure I am) would take. Of course, it would be hard work, much harder than bundling together a bunch of other people’s over-processed data and pretending you’ve done something useful.

    ==============================

    And while thinking about this, without having read Mann’s work, how can you possibly use principal component analysis when you’ve only got one parameter? I mean, everyone knows that PCA is a way of taking a data set with multiple variables, and reducing it to a manageable handful of variables (which, if you’re lucky, can be related to other, identifiable features). I can’t do it myself, but I’ve watched people do it with multi-element geochemical data,and it’s a pretty neat tool. But the thickness of a tree’s growth ring is only one variable. What am I missing?

    • Smart Rock

      I had a look at Bradbury’s book from 1999 and commented over at Bishop Hill. There’s a chapter (10) about dendro reconstructions. They use this type of multi variate technique. In principle the technique is sound. In reality not so much if you want it to be useful

      To get good relationships you need good metrology, which requires painstaking characterisation if you want low uncertainty. For example, trees don’t grow according to temperature anomalies and they may not grow linearly (something Craig Loehle did a paper on in the past).

      Common sense would tell you that you need to put in great effort to squeeze out that accuracy if you want tree rings to be useful thermometers. It may just not be possible.

      For a theoretical exercise I don’t see any problem with it. I worry however that this paper may end up in some climate report as “evidence”.

      • “Take a few well-studied forests over a well-documented time span (e.g. the 20th century). Then try to isolate a species whose growth responds more to temperature than rainfall, and another species that responds more to rainfall, and another species that responds more to sunlight/cloud cover, and another that responds more to length of growing season (which is only loosely linked to temperature). ”
        Why should anyone suppose that species exist that respond to such well defined but separate growth factors in the required way? Let alone exist within a single long lived and well studied forest? And that all of these relationships remain unchanged over long spans of time?
        Sounds like how to make something that does not work, into something that is much more complicated and questionable, that does not work.
        Hey, you should maybe apply for a climate science grant! Sounds like you have a winner!

    • Genetic variability of the seeds disbursed by a tree ensure that if conditions change, there will be some individual seeds that are able to thrive under these altered conditions. The lifespan of temperate forest trees may ensure that over a period of many hundred years, there is a predomination of trees that grow best at the prevailing average temperature.
      In other words, it may well be the case that trees adapt to changing conditions through natural selection. I see no reason to expect that in a given area, as we transitioned from the MWP to the LIA, and then to the MWP, trees are not able to subtly adapt to these changes, and are principally affected by deviations from the long range averages over short periods of time.

    • You aren’t missing anything. The fact that tree rings reflect a number of variables obviates the ascription of any one variable as causative. Down thread I asked why recorded history is never used as an analytical variable. I have always wanted to see someone take tree ring analysis and try to correlate it to recorded human literature. For example, TonyB and others (Steele and Ball?) have reported historical records of catching fish well north of their range, the farming in Greenland, the distributional changes in seals and polar bears, the discovery of the PDO by a salmon scientist and other natural responses to climate variability. Critters only respond to environmental changes if they have to, and it has to last long enough for a response to occur. Surely, some of these tree samples have been taken in Europe, Eastern Canada and other locations that had to be affected by temperature changes that would be reflected in tree rings (if temperature is the operative factor). If you are going to claim tree rings reflect climate change, then let’s be honest enough to test it against other natural changes.

  39. Willis:

    Thanks to you WUWT now needs a humor section.

    Don’t get me wrong — I followed your critique and I love the post. It seems to me that you are right on!

    Luckily I forgot to bring my coffee to my office or I would be sending you a bill for a new keyboard as I’m sure that my coffee would have been spewed all over.

    When I read the BH post I looked up the paper — decided it did not pass the smell test and went on… Clearly I missed some merriment. Thank you for setting me straight.

    Jimmy Durante move over — you have a new companion in the Wax museums of today!

  40. I did a study of tree rings when I was 18 years old for an alpine ecology class in Switzerland. The tree I studied Picea Albies (Norway Spruce) grew fastest at an elevation of 1400 meters. It grew slower above that elevation due to a colder shorter growing season, but it also grew slower at the lower elevations, where it had progressively more severe completion from deciduous trees. At 400 meters the few straggling trees I could find had the same growth rate as the trees at 1800 meters, which was alpine tree line. I knew from one study they are a poor proxy for temperature.

    • Let us hope that you used proper spelling for your main subject.
      The word is abies, not albies.

  41. My home is largely paneled in old-growth coastal redwood (built in 1909). There are beautiful diagonal stripes in the quarter-sawn panels, which are taken from the lower trunk, caused from compression of the cellulose from the colossal weight of the tree, which often exceed 200′, and will commonly top 300′, tall. The tallest living specimen is about 380′. If one were to take core samples at different heights on the base of the trunk, one would see thin rings at different radii, corresponding to these diagonal stripes. This should be an issue with any large tree, even if it’s not large enough to cause a visible figure in the wood when quarter-sawn. This would be similar to glacial cores where a similar compression from snow to firn to ice occurs. I think that, in addition to all of the other issues with using dendochronology as a thermometer, this effect will give spurious results as one looks at different trees, of different sizes, at different heights, etc. I’ve never seen any treatment of this error source. Perhaps that is because by the time you look at all of the other error sources, you should just toss this method anyway…

  42. The problem with tree rings…is even if they had a perfect correlation with temp and nothing else…you still could not use them and they still would not work

    They can’t tell you how much hotter it got and for how long after they stopped growing…..or how much colder it got and for how long

    Those temperatures outside of their growth range are just a WAG…made up…and can be made to say anything you want

    • Latitude, in a comment above it was revealed that these studies only purport to relate summer temps to growth rates. I wondered why anyone should think summer temps are a valid way to arrive at world average temperature.
      Is this what you are referring to as well?

  43. N-TREND shows a hockey stick. Temperature measurements do not show a hockey stick. Does this show that tree rings can not be used as a proxy for temperature, using expert judgements?

  44. They didn’t need all those trees. Briffa showed that one is enough, if the right one is picked:

    Johanus says above:

    … this unit conversion could be just eye candy to impress its targeted lay-audience.

    IMHO that is exactly what their intent is. Their graph says it all. Most people will never read the paper, or even a summary. The graph will be published throughout the media, people will see the hockey stick at the end and think, “The scientists must be right! Looks like global warming is accelerating fast.”

    That’s exactly what it looks like. But in the real world that’s not happening.

    As Willis shows, that graph was deliberately fabricated from very questionable proxies and data. The graph is the goal, more than the paper — which is just the science veneer to make it seem legitimate. If someone questions that graph, the alarmist crowd will parrot, “It’s peer reviewed!” That’s been the pattern, over and over again.

    Over the past century global temperatures have risen by only ≈0.7ºC. That is a smaller change in global T than almost any century long time frame found in the geologic record. But they are trying to make it look like global T is now skyrocketing. They’re lying, no?

    Johanus adds:

    But let’s reserve judgment until after reading the full paper.

    Let’s not, Johanus. At this point they would have to produce an extremely convincing paper, showing that other temperature databases like satellites and radiosondes are completely wrong before I’d accept their Mann-style hokey stick chart.

    My judgement is already in: they’re lying by chart.

    • I am still searching for a definition of the scientific method which includes any reference to the pal review process.
      How did this become the gold standard for what is valid science, let alone what is objectively true?
      Particularly since the process seems to be little more than a redundant spell check?
      Particularly since one can shop around if one’s first several bunches of attempts to have a paper peer reviewed and published hit a stone wall (just ask John Cook)?

  45. The supposed justification for normalizing such data (besides the proxies which are not even temperature…) is to avoid the problem that reconstructions from Iceland will be colder than those from Africa and perhaps more variable. However, the correct way to deal with this is to weight regional proxies by their geographic regional area, not normalize. This screws up everything in my opinion.

    • Yet no one bats an eyelid when GISS LOTI and HadCRUFT4 [sic] average land air and sea surface temperatures.

      This skews the result because air temps change about twice as quick as SST and so have twice the effect on the result , even when area weighted.

      Plus this nicely adds UHI effect into the SST which does not suffer from that problem.

      The end aim of all these temperature reconstructions is to compare them to radiative “forcings” and estimate climate sensitivity. Yet if you “average” the temperature of media with vastly different specific heat capacities ( air , land, water ) or start rescaling and adding, any physical meaning disappears and the CS calculation becomes totally false.

  46. Dendrochronology IS a science. It’s a very detailed and exact science, and its usefulness lies in its ability to date wood. That’s about it. A dendrochronologist helped to convict the kidnappers in the Lindberg baby case (the used and discarded ladder to access the child’s room was made of wood).
    The Anasazi ruins were dated using dendrochronology. Very exactly, too. No one I know disputes the conclusions.
    But to pretend it’s a useful proxy for temperature is absurd, and I doubt any arborist, or forester, or horticulturist would consider it as such.
    Using the climatologists logic, 2012 in the Midwestern US would show up as a very cold year, because the growth rings were so truncated (hee). It was very hot, and very dry.

    • Why do you criticise Briffa ? He published a proxy with a decline , it was Mann and Jones who tried to suppress it.

      • Briffa published a time series in which only one of 12 trees showed a hockey stick. He’s as dishonest as Mann and Jones.

  47. From the article: “all of the proxies had been “normalized”, that is to say, set to a mean of zero and a standard deviation of one.”

    This is because each specimen has unknown parameters such as relationships of temperature/moisture to growth, so their normalized proxies are thus comparable to each other and otherwise would not be. After combining them you can estimate the impact of temperature on growth per each proxy by using the others as a (circular) reference, but it’s a hodge-podge, GIGO even. How you’d estimate the errors beats me, and catastrophic error would be a real possibility if not likely. So the normalization is essential as a starting point, anyway.

    The conversion into standard deviations is evidently meant to strengthen the weight of the most conforming proxies. This is like an iterative Bayesian process and has GIGO all over it. Anyway, that’s my brief assessment.

    • “…so their normalized proxies are thus comparable to each other and otherwise would not be. ”

      How do you arrive at that conclusion? That is Willis’ main point. The original papers had already attributed the scaling. This information is thrown out in place of an arbitrary “normalised” scaling. Why do you conclude that this makes them more “comparable”?

      If you have rain gauge data from a group of cities, you can add them to get a total rainfall series for the region. This may be related to the total energy causing evaporation. If you normalise the data and add them you lose all physical meaning. Rescaling them afterwards will recover the lost information.

      You have degraded and muddied the information because they are NO LONGER comparable.

      • Mike: There’s no defensible way *not* to normalize them because of unknown microclimates! For each specimen the unknown microclimate and unknown individual growth characteristics control the growth rings as least as much as the macroclimate. Normalizing cleans that out, but removes the “physical meaning” as you note. Now to fit each individual profile into the ensemble recovers the macroclimate, but how to separate the temperatures from the precipitation seems insoluble — it’s what’s called a “degenerate” solution where you can’t separate them. Short term proxies are controlled by long term proxies which, however, show less detail. And the Bayesian prior restores the “physical meaning” in the form of GIGO. I don’t think this approach is publishable except with very friendly reviewers.

      • Before one even gets all the way to what you guys are debating, one has to get past the phrase “expert judgement”.
        To me, this sounds like the entire exercise is nothing but opinion.
        In light of that, nothing else even matters. IMO.

      • NZ Willy January 16, 2016 at 6:20 pm

        Mike: There’s no defensible way *not* to normalize them because of unknown microclimates! For each specimen the unknown microclimate and unknown individual growth characteristics control the growth rings as least as much as the macroclimate. Normalizing cleans that out, but removes the “physical meaning” as you note.

        Thanks, Willy. Ah, but the same is true of thermometers. Thermometers are as subject at trees to what you call “unknown microclimates!” complete with exclamation mark.

        And again, for both trees and thermometers the unknown microclimate controls the temperature as least as much as does the macroclimate.

        So if the issue is the existence of microclimates as you claim, should we normalize our thermometer readings in order to “clean that out”, as you advise?

        Regards,

        w.

  48. Has anyone noticed that because of the lack of “data” for the last 20 years (why?) coupled with the fact that the amount of data significantly decreases the closer the date is to present that your eye “magically” draws a line from the end of the red line up to the darkest part of the blue line at the end of the chart? Expand the chart on your display and step back a few feet from the monitor an look at the graph again.
    However, even that dark lump of data at the end is actually not much higher than the dark area in the year 1950 (or so)! Looks to me that they are definitely playing with the data.

  49. “This strategy explicitly incorporates the expert judgement the original authors used to derive the most robust [temperature] reconstruction possible from the available data at that particular location …”.
    =======================
    That amounts to a blatant appeal to authority.
    How is one to verify the expertness of a dendrochronologist?
    Is it a matter of good old ‘consensus’, ‘you say I’m an expert and I’ll say you’re an expert’?
    Do dendrochronologists ever replicate each other’s results, do they ever disagree?

  50. I feel that attempting to establish environmental temperature from tree ring studies is optimistic to say the least. As others have pointed out, water supply is the dominating factor, followed by exposure to wind and light. There is even variation in each year’s ring width around the circumference. It can be clearly observed in a branch where the compressed underside displays a different ring width to the upper that is subject to extension. Trees subject to prevailing winds display the same patterns, in their trunks. Should for some reason a tree be subject to change in effective wind direction the variation in the trunk rings will ‘rotate” making things very difficult to interpret

    There is also the problem of growth spurts during certain stages in aging – just as is the case in fauna. There is always competition between trees such that the winners get most of the light and will show a growth spurt not displayed in a neighbour that has been deprived of light (unless of course they are a shade species). They will have different ring signatures. I have no doubt that experts in the field are aware of these factors but cannot deny that they potentially effect accurate interpretation

    I recently cut down some trees on which I have a fairly accurate idea on planting date (approx 130 yrs) I have a very good memory on key years in relation to rainfall over the last 50 years. We had a string of hard droughts in the 60’s. This event is clearly displayed by ring width variation approaching 75% when compared with the prior and latter more normal years. Annual rainfall during the draughts was probably around 75% of our normal average of 1800 mm. Yet, the droughts occurred over the warm months when growth is usually at its highest

    I have a neighbour who has religiously kept rainfall records since 1966. The next step is to correlate these. So much fun, is this science :-)

    Whatever, the key message is that establishing paletemperature through tree ring studies is problematic – as I see it. One would have to be very selective over which species and environment to study. Tundra may be the best bet. Taking any old data from the past aint going to do it

    • Thank you, Mike. I was relating my experiences with bamboo while you posted this. I have lots of trees but seldom handle them, so I hadn’t considered these interesting points you raise, especially about competitive growth. Lot to think about. Let’s hope the ring-counters are also doing some thinking along these lines.

  51. OK, I averaged all 54 data series from 1710 to 1988. The period for which they all have data. Then I plotted the results without any statistical nonsense. Here is the result. As can be seen temperatures have been rising steadily since the early 1800’s, long before CO2 was an issue.

    This is VERY STRONG evidence that CO2 is not the cause of the current warming!!

      • When I made the point in an earlier comment that this study actually supports the conventional sceptical view of MWP, LIA and modern warming period I was seriously criticised.

        Whether or not you agree with the use of tree rings you have to accept that the authors of this study have been prepared to “stand or fall” by their method. They have not used tree rings for the earlier and then grafted the thermometer record onto the reconstruction in the later years.

      • Whether or not you agree with the use of tree rings
        ============
        I accept that if tree rings are a valid proxy for temperature, then the N-TREND2015 data provides very strong evidence that the modern warming cannot be due to CO2, because it is plain to see that the warming started long before CO2 was an issue.

    • This is VERY STRONG evidence that CO2 is not the cause of the current warming!!

      Ferd, why is this strong evidence? Are you suggesting that because tree rings have gotten larger over the past 200 years we can conclude CO2 isn’t causing warming? How do you reach this conclusion?

      Wouldn’t it be more supportable to measure temperature, measure CO2, and test for a correlation? We can do that now, so I don’t understand the reason for this analysis, or why it wouldn’t be equally valid to conclude increased CO2 released by a warming ocean had increased tree ring width over the same period?

      • Ferd, why is this strong evidence
        =============
        what I was referring to was human created CO2 from fossil fuels, which was not significant at the time the modern warming starts according to the tree ring data.

        human CO2 from burning trees will not increase CO2 significantly, because the trees represent CO2 taken out of the atmosphere.

  52. A bit OT, maybe: I grow moso bamboo, which obviously doesn’t resemble any tree in growth habits and patterns. There are new annual culms instead of rings, just for starters. However there is a principle to be considered here:

    If I look back at recent records of temp and rainfall they tell me very little about how my ‘boo actually grew in that year. All the critical things which lead to a good shooting year need to come together in a certain way. Heat and rainfall need to be timely, and rainfall has to be VERY timely. Damage in the vulnerable spring weeks from wind and animals can lower results in a good year (animals are more likely to damage in a dry spring, but good La Nina rain in mid-spring comes with southerly winds which are not so good). Some effort from me or some good late luck with rainfall can make a bad year better. These results will not show in the weather record, only in the size and number of poles in that year. I’d add that while La Nina leaves a pretty clear visiting card in my grove, El Nino does not.

    What I’m saying is that my ‘boo is a lousy record of temp and rainfall, and I suspect that if I lived long and closely enough with some other type of plant I’d start to realise much the same thing about it. With trees, I’m guessing that if rain or warmth comes too early or late for optimum growth in one or even more studied species you may conclude wrongly that there was not much rain or warmth in that year. I know that dry late winter/spring conditions, combined with high heat, can be followed by a damp and somewhat cool summer in my part of NSW. Some species will prosper when that happens, others won’t. Lastly, some plants just relax and clock off, some decide not to grow every year – I dunno why, they probably don’t know why. Maybe they’re tired or complacent or unhappy with their situation. Not getting all their minerals for their time of life?

    So dendrochronologists are like the rest of us. They still need commonsense and they need to get out more.

    • For example, I have several Buckeye trees on my property. On the years that the blossoms appear at the right time,they get pollinated to the max, it doesn’t freeze on them it makes no difference how much it rains or how warm it is the trees put all of their “growth” into buckeyes – NOT making a larger, taller tree. The years that there is a frost on the blossoms and there are few if any buckeyes they grow 18 or more inches taller that year, with only average/normal temperature or rainfall. The same correlation must exist with other trees that produce seeds, just not as obvious.

      • It’s a sorry fact that many highly numerate scientists are too mechanistic and literal-minded about data. The way “temperature” is constructed from of min/max readings, regardless of cloud, wind etc, is downright alarming. Do these people seriously not notice the effect of cloud cover, often radical and having effect at the very time of day or night where min/max potentially occur? Or do they pretend not to notice because it would kill the entire game?

        Which brings us back to tree rings. Heat followed by afternoon thunderstorms will likely give more growth than overcast weather with the same amount of rain – though maybe not at night, if the temp stays high due to cloud cover. It’s never just the numbers of millimetres and degrees…it’s the PATTERN of cloudiness, rain and warmth you have to know an awful lot about.

        Then you have to reconcile all the other complicating factors raised by commenters like Menicholas, Michael C and usurbrain. And, of course, one simply can’t reconcile it all. Better to live with permanent uncertainty than with junky assumptions turned into tables and graphs.

      • I agree mosomoso: On the Canadian prairies the combo of temp and precip matters most. The temp is seldom a limiting factor because it really doesn’t vary that much. The timing of precip, however, is ultra-important. Because we are a “DRY AREA”, precip plays the major role. Even in years when climate is not favourable, as long as you have enough moisture for germination, one early rain and one mid-summer rain is all you need for a good crop. We call the mid-summer rain a “million dollar rain”. Why would trees respond any differently?

  53. ferd – a 1c variation over 3 centuries derived from tree ring data? Thanks for the work. Its interesting but really of no use – to anyone – except to re-establish that we, as yet, know F.A. We need more poker players here to give us the home truths :-)

    • but really of no use
      ================
      it establishes that if tree rings are an accurate temperature proxy, then CO2 CANNOT be the cause of the modern warming, because the warming started more than 100 years before significant CO2 production.

      The way truth is established in science is by elimination all possibilities that cannot be the cause. So far CO2 was the ONLY thing that had not been eliminated. This result eliminates CO2, which means that the real cause of the modern warming IS UNKNOWN.

      • Ferd writes: “it establishes that if tree rings are an accurate temperature proxy”

        So, if fudge brownies were an accurate temperature proxy? It’s a big If Ferd, and the subject of the conversation I believe. Asking anyone to simply take that as given absent any evidence is a very large stretch I think.

        “CO2 CANNOT be the cause of the modern warming, because the warming started more than 100 years before significant CO2 production.”

        CO2 CANNOT be the cause of warming because over the past 19 years we’re observed a very large increase in atmospheric CO2 and no increase in average global temperature. That requires no “belief” in tree rings and their relationship to temperature or CO2; it’s a conclusion based on direct measures of temperature and CO2.

      • So far CO2 was the ONLY thing that had not been eliminated.

        CO2 has been eliminated near as I can tell Ferd. The RSS AGT data for the lower trope taken over the past 19 odd years hasn’t changed significantly. CO2 has risen over that same time period by more than 30% of all CO2 ever released by humans.

        It’s now impossible to claim CO2 causes warming. There is absolutely no basis for the claim. It’s absurd to complicate this question by adding chicken bones, tarot cards, tree rings or spirit tapings to the equation.

      • ferd – Can we really trust tree ring data to be accurate within 1c over 3 centuries (or at any time) ? Its not something that someone with any sense would bet money on. This is the kind of flimsy argument that the alarmists use. The topic is cluttered with such worthless information. We always have to consider the odds of probability in relation to the robustness of the data

        PS: this is not a personal attack. Cheers :-)

      • Can we really trust tree ring data to be accurate within 1c over 3 centuries (or at any time)
        =============
        I’m suspicious that the proxy data may have been already “calibrated”, in which case it cannot be trusted at all.

        If these proxies are a random sample of trees from a temperature limited area, that would be reasonable. However, if these are tree ring samples that have been filtered based on how well they correlate with thermometer data, then we are looking at statistical garbage data.

        The entire field of Dendrochronology has a serious problem with “selecting on the dependent variable”. Google the term. The other sciences like medicine and economics have woken up to the problem, by Climate Science is still stuck in the Dark Ages of statistics.

        Statistics relies on the assumption that your data is a random sample. Your are trying to solve for temperature from the tree rings. Temperature is the dependent variable. If you use temperature to filter the tree rings, you are introducing selection bias.

        In effect, the original problem is solve:

        temperature = function (tree rings)

        calibration turns this problem into

        temperature = function (tree rings, temperature)

        And what statistics does is solve this as:

        temperature = 0 * tree rings + 1 * temperature

        And as a result you can prove up is down, left is right, or CO2 causes warming, or CO2 causes cooling. Anything you want.

      • it establishes that if tree rings are an accurate temperature proxy

        I’m not sure we can quite go that far but we can probably deduce the climatic conditions of the time from tree rings. Since temperature will be a factor in those conditions we can probably have a reasonable stab at the relative warmth of the MWP and the LIA and the 20th century.

        Everyone’s getting hung up on the accuracy and precision of the proxies and the method used to estimate the anomalies. It’s probably more accurate to think of the anomalies as climate indices.

        This latest study is not the same as the Mann study which was wrong on 2 main counts. Mann’s use of PCA introduced the anomalous and unrealistic post-1900 uptick in temperatures but, worse than that, Mann’s reconstruction used the thermometer record to represent that last few decades of the series. He was comparing apples with grapefruits.

        The N-TREND15 researchers have, rightly or wrongly , been prepared to stand of fall by a methodology which they have applied consistently across the entire time series. If there is a criticism of bias it is that they extended their analysis up to 2004 which might be pushing it a bit given the drop off in the number of proxies available.

    • Industrial Revolution began in 1750
      ==========================
      It probably began in 3500 BC, with the invention of the wheel.

      Humans have been emitting excess CO2 since 1 million BC with the domestication of fire. That is what caused the end of the Ice Ages.

      • It also credits Edison rather than Swann with the incandescent lamp.

        However, I am inclined to begin the industrial revolution with mechanised mass production, not powered by humans or animals. (Early printing presses were human powered.)

        A tricky bit here. Do windmills and watermills for grinding corn count as mass production? The dark Satanic mills of Britain were called mills because the first cotton and wool weaving factories were water powered.

        Once they are steam powered, then we are clearly industrial. Perhaps, for our staring dates, we should look more at the social effects than the means employed. It was, after all, a revolution.

      • I suppose a person could suggest the industrial age began with the engine then, but that would take it back at least to the water or wind mill as you suggest. I think common wisdom centers on the steam engine as the beginning?

      • Newcomen, then. 1712.

        But I didn’t know there was any common wisdom, just what we learned at school. We all learned that there was an Agricultural Revolution (crop rotation and Jethro Tull) and then an industrial revolution. Both these things happened in England, and the benefits extended to Australia when it was settled. Might have affected the rest of the world, but no-one gave a toss about that.

      • It was only long after we had left school that we found out that Tull invented the seed drill in between gigs.

    • Ferdberple wrote: “correction: dendroclimatologists”

      Or perhaps we can broaden that to PaleoClimatologists?

      The sad (and inconvenient) truth is climatology is no longer a backyard science. The advent of Average Global Temperature, which was historically measured by amateurs who trusted one another and did their very best, as scientists, to provide the highest quality data they were capable of, and who implicitly trusted each other, has been co-opted by “big science” and there’s no turning back.

      We’re now completely dependent on data provided by billion dollar, multi-national, government sanctioned efforts. We depend on a communications architecture that was once un-regulated, became regulated, became un-regulated again briefly, and is now regulated again.

      I tend to believe the data I receive from Mauna Loa and RSS. Why? Because I think it makes sense. Do I have any guarantee it represent some kind of scientific integrity? No, I don’t. I don’t know if those data have been manipulated. No idea at all.

    • John Finn: Of what value are ball-park figures of a degree or two of temperature change when they are claiming 0.04 degrees with a 38% probability?

      • John Finn: Of what value are ball-park figures of a degree or two of temperature change when they are claiming 0.04 degrees with a 38% probability?

        Because you are using the proxy reconstructions and the surface temperature record for 2 different things.

      • John Finn:

        R2Dtoo asked you

        John Finn: Of what value are ball-park figures of a degree or two of temperature change when they are claiming 0.04 degrees with a 38% probability?

        and your total reply says

        Because you are using the proxy reconstructions and the surface temperature record for 2 different things.

        Your evasion is ridiculous!

        R2Dtoo made no mention of uses. He asked you a straight question and your silly evasion demonstrates that you know its answer is
        ball-park figures of a degree or two of temperature change have no value when they are claiming 0.04 degrees with a 38% probability.

        Richard

  54. Thanks Willis for yet another excellent critique. The “Expert Judgement of the original authors” seems to have been primarily deployed to recreate at all costs, the previously demolished Hockey Stick for re-use in 2016.
    How much do trees preserve a record of temperature and how much do they preserve a record of rainfall variation, fertilisation from animals, lightning strikes and forest fires, variation in tree age ring width, variation from topography, and finally variation of CO2 levels?

  55. “… well … a strangely circuitous route. I mean, if you start with proxy temperatures in degrees C and you are looking to calculate an average temperature in degrees C, why change it to something else in between?”

    Willis,mare you really so naïve? If they don’t do it that way, they might get the wrong answer.

  56. I make the following bets;

    One of the proxies will be upside down.
    Several of the proxies will have been described as not useful for temperature reconstructions.
    There will be bristlecone pines involved.
    The mapping of proxies will be wrong.
    What is missing is more significant than what is included.

    • What is missing is more significant than what is included.
      ================
      the proxies will have been “calibrated”. In other words, they will have been filtered according to how well they fit the thermometer data.

      • ferdberple:

        You say

        the proxies will have been “calibrated”. In other words, they will have been filtered according to how well they fit the thermometer data.

        Yes, and that is the confounding problem with the formulating assumption of dendroclimatology.

        The entire activity of dendroclimatology is attempts to justify an untrue assumption;
        i.e. dendroclimatology and astrology are similar activities in both their theories and their practices.

        The basic method and practice of dendroclimatology is as follows.
        1.
        Trees are selected as being good “indicators” of temperature over the ‘calibration’ period.
        2.
        That selection assumes the trees with rings that correlate to temperature are indicative of temperature.
        3.
        The assumption is not valid because natural variability will result in some trees correlating to temperature if sufficient trees are examined.

        (Astrology assumes that planetary positions correlate to events on Earth.)

        Richard

      • NOTHING from California should be used to gage global climate situations because, like Australia, California has a ‘non-ice age’ environment that varies rather little compared to other places like, say, England which moves from Ice Age total glaciation to very mild climate, even warm.

        The main place to keep track of all this is Hudson Bay. All glaciation of North America starts there and when it is ice-free is when the climate is very warm. It is frozen over as per usual right now as it is in winter these days so our present Interglacial isn’t so hot, after all, is it?

    • The Port of Churchill in is Hudson Bay. A few years ago they thought that global warming would open the port for a longer season. Now they are trying to sell the port. Nough said!

    • It may turn out that that’s exactly how they got their hockey stick: thin data inflated by means of (1) bizarre weighting factors acting on a handful of defective series; (2) end effects; (3) mathematical error; and (4) gigantic error limits. I hope not. That final data point looks highly suspicious.

  57. I suspect that there is probably a wealth of useful research out there that – because it has been presented in the most appropriate manner – has not been identified in relation to climate studies. A good paper simply presents background, method and results, and a discussion on inferal without necessarily linking to climate change. True? Ironical. Only the arm-wavers are noticed

  58. @ntesdorf

    How much do trees preserve a record of temperature and how much do they preserve a record of rainfall variation, fertilisation from animals, lightning strikes and forest fires, variation in tree age ring width, variation from topography, and finally variation of CO2 levels?

    Good question. The dendroclimatologists like Wilson et al. are claiming that recent increases in tree ring widths are a direct response to recent global warming caused by recent man-made CO2.

    All of those other factors you mentioned above are probably involved too. But I think increased CO2 levels may really be the biggest factor. But not because of global warming. It seems to me that increased CO2 directly will increase the amount of carbon fixation in the tree ring growth. In other words, the tree rings should be wider now because there because the tree produces more cellulose and other organic material from the additional carbon absorbed from ambient CO2 in the atmosphere.

    Of course plants grow faster in the summer when it’s warmer, and not so much in the winter when it’s colder. That’s very basic science. So increased tree ring width may also be correlated to temperature, but temperature is not the cause of the recent increases in tree ring widths. (Because temperatures have risen much during the last 18 years)

    Increased CO2 is more likely to be the cause of tree ring growth and is in fact responsible for the increased greening of the entire planet.

    So why doesn’t the Green movement embrace CO2, that wonderful and amazing plant food?

    Politics.

    • So why doesn’t the Green movement embrace CO2, that wonderful and amazing plant food?
      Because CO2 is the debil.

    • > I’m not sure “dendroclimatologists like Wilson et al. are claiming …
      Then why do they seem to be fabricating an egregious “hockey stick” where none exists in the instrument record? I haven’t read this latest paper, but I would be willing to bet they pay homage to the AGW god somewhere in that document.

  59. John Finn January 16, 2016 at 1:32 pm

    Whether or not you agree with the use of tree rings you have to accept that the authors of this study have been prepared to “stand or fall” by their method. They have not used tree rings for the earlier and then grafted the thermometer record onto the reconstruction in the later years.

    Thanks, John, but I’m not clear what your point might be. Do you think we should be congratulating the authors because they haven’t done anything underhanded?

    w.

    • No, Willis, I’m suggesting we don’t get too bogged down with the precision and accuracy of the anomalies and look at the relative period values. Whether by luck or design the reconstruction has managed to produce a record of past climate which is not too different to that recognised by a number of AGW-sceptical researchers.

      Put it this way: I wouldn’t dream of comparing anomalies from the reconstruction with anomalies from the thermometer record but I might find the relative values of, say, 1946-55 (0.30) and 1812-21 (-1.03) credible, i.e. I’m happy to accept that mid-20th century temperatures in the NH were about a degree or so higher than in the early 19th century.

      I’m not criticising your analysis Willis which is perfectly valid but the response to it from readers. It’s important to recognise the distinction between this study and the Mann H-S study and this one.

      • John Finn January 17, 2016 at 2:28 am

        No, Willis, I’m suggesting we don’t get too bogged down with the precision and accuracy of the anomalies and look at the relative period values.

        Say what? Until you determine the precision of the anomalies, you have no clue if the relative period values are valid or not. For example, the recent part of the record might be fairly precise, but the previous period might not be precise at all. In that case, you cannot make any assumptions about the relative period values … and we have no assurance that ANY part of this greatly munged record has the slightest resemblance to the temperature.

        You can’t just wave your hands and say something like “Well, it looks kinda like what I think the temperature history ought to look like, so I can use relative values to compare periods”.

        w.

  60. Eh, rent seekers.
    Me thinks the swinging pendulum of scientific integrity will start to turn when this flock of boomers retires en masse and emeriti outnumber rent seekers. Seems reasonable.
    Reminds me of the fed chiefs who retire and start speaking out about the illegal front running that took place while they were at the helm.

  61. Willis – too much here to even hope going through and I will wait for anything coming through CA.
    However, the nesting approach used to derive the recon (and calibration/validation stats) in Figure 2 is essentially averaging. Just an iterative approach meaning that the averaged are re-calculated every time a shorter series drops out.
    As stated, the record shows “reasonable” fidelity for the period 918-2004 – before/after replication drops too low and the estimates get erratic. I certainly would not trust the 2010 value for example.
    Finally – please look at Appendix Figure C1 – there are multiple different flavours – derived using different weighting strategies and methods. I am thankful that you have replicated the basic shape that is expressed in the large scale mean.

    • Thanks, Dendrob. I understand that the nesting approach is a flavor of averaging. It has to be, or else the authors wouldn’t get a “reconstruction” which is essentially a simple average.

      I’m more concerned about the entire chain from observation to reconstruction, viz:

      • Certain tree rings were selected for examination by a variety of authors, based typically on unknown or incorrect metrics, and without clear ex-ante proxy selection criteria. I would be shocked if among the 53 proxy records a significant number of individual tree ring records had not been data snooped or chosen based on their correspondence with local temperature.

      • These authors either utilized or developed some mechanism for transforming raw tree ring measurements into temperature estimates.

      • Other authors select previous reconstructions for examination, again based on unknown metrics, and without clear ex-ante proxy selection criteria.

      ° These reconstructions are normalized based on an arbitrary time period, in this case 1750-1950,

      ° These normalized reconstructions are averaged, and the average is declared to represent the temperature history of the Northern Hemisphere.

      I’m sorry, but I don’t find that process to be either particularly reassuring, mathematically defensible, or precise. Too many authors, too many different methods, too many transformations, plus the normalization equals large and unknown error bars.

      Best regards,

      w.

  62. I am confused. I thought that proxies In the Briffa reconstructions showed a decline after 1960 (“hide the decline”). Not so according to Wilson’s graph where the proxies do show a sharp increase in the T anomalies.

    • There is a decline. The pre-1990 peak temperature occurs in the 1946-55 period. The temperatures don’t reach that level again until 1994-2003.

      Ignore the post-2000 values. The number of proxies available was significantly lower than for previous periods.

  63. From the study paper:

    In two important periods of climate transition, the cooling from
    the medieval period (900-1250) to Little Ice Age (LIA –
    1450-1850), and the post LIA warming to present, the TR reconstructions
    and model estimations differ. During the medieval to
    LIA transition (Fig. 5C), the amplitude of temperature change from
    warm to cool, as expressed by N-TREND2015, is greater than most
    models and other TR reconstructions.

    It’s methodology may be flawed (though I’m not convinced this is terribly relevant) but this is not a pro-AGW study.

  64. To Willis and others who have argued against some of the points I’ve made in this thread.

    I’ve been as a big a critic as anyone about the inappropriate use of tree ring proxies to estimate temperatures. This is a link from 2004 which includes an exchange between myself and Michael Mann about many of the issues which have been discussed here.

    http://www.realclimate.org/index.php/archives/2004/12/myths-vs-fact-regarding-the-hockey-stick/

    I’ve since had a fairly detailed look into the issue. I know about (and accept) the “upturned U” response to temperature. We all know that temperature is not the only – or even the main – driver of tree ring growth. I’ve taken all these issues on board and have formed the following conclusions:

    1. Can we use tree rings to estimate temperature anomaly for a year or multi-year period and compare it with a similar length period in the thermometer record. No We can’t – No chance
    2. Can we select an anomaly for a single year from a proxy reconstruction and compare it with the anomaly for a different year (e.g. 1250 v 1850) No we can’t – not even to say that Yr1 is warmer or colder than Yr2
    3. Can we select a decadal (or multi-decadal) period from a proxy reconstruction and compare it with another decadal (or multi-decadal) period from the same reconstruction and make any assumptions about the relative warmth of the 2 periods. Yes – I think we can and I think it might also possible to put a ball park figure on the temperature difference between the 2 periods.

    This study finds an extended MWP which is about a degree or so warmer than the LIA. It also finds that the late 20th century is also about 1 degree warmer than the LIA. It finds no evidence for modern warming being warmer than the MWP or vice versa. I’ll dig out Hubert Lamb’s reconstructed temperature series to see how it compares.

    Of course there is one problem with the study. It finds that 1946-55 was warmer than any other non-overlapping decade up until the mid-1990s.

    • “Yes – I think we can and I think it might also possible to put a ball park figure on the temperature difference between the 2 periods”

      John – 1 C is one blade of grass in the ball park. Tree rings read to this precision? Sorry, nah. Annual rainfall variation as a percentage compared with temperature variation? And what about seasonal variation? Ask a gardener about that

      I am a skeptic of very precise results. No offence intended

      • You should be skeptical of precise measurements in heterogeneous environments. Unfortunately, healthy skepticism of the above perpetuates the funding of yet even more effort to develop precision. This of course then leads to tunnel vision concerning the particular variable you are measuring. Then of course multitudes of trained measurers gather together in fancy places beating their breasts concerning the true measurements for the one variable that answers all things.

        Then they get tenure and teach others the above process. Science will maintain the rut of hubris until they can figure out how to unravel the above.

      • I get your point. The trend now is to find a trend whereas within the time frames we are looking, and within unbiased data collection, results are more likely to show a mosaic of noise ie no obvious trend within the practical degrees of accuracy. The pre 1950 sea temperature ‘result’ could easily be as much as 3 C out. Someone prove me wrong! :-)

  65. I’ve re-analysed all 54 datasets for the period 1710-1998, the period where all sets have data. No statistical nonsense was applied. Calculating both the average and standard deviation, there is an interesting result!

    For the period 1710 to 1998, there is virtually no change in the 30 year average of the deviation. What this says loud and clear is that there is no evidence in this data for climate change being due to anything other than natural causes. There is no evidence that industrialization is affecting the variability of climate. Otherwise we should be seeing a statistically significant increase in the variance. But we don’t.

    • Nice image.
      I saved it.

      Execution of the precautionary principle concerning CO2, globs of funding to measure it and demonization of fossils will continue till the money finds another mass movement to pyramid in on.

      Social justice
      Sustainability
      Deserved
      ….

      Listing key buzzwords in the branding scheme of things.

  66. Sorry – no time to read above comments.

    The subject study has no technical credibility.

    The post-2000 temperature spike has no support in the surface temperature record, the radiosonde weather balloon record or the satellite temperature record.

    However, the authors do deserve some kudos: they certainly did manage to eliminate the “Divergence Problem” and “hide the decline”. Bravo!

    • eliminate the “Divergence Problem”
      ===============
      if you look at the my graph immediately above, the post WWII cooling period is quite evident in the tree ring data, consistent with the historical records of the time.

      The problem is that homogenization and other adjustments to the surface data have eliminated the post war cooling period from current records, which gives the false impression that there is a divergence.

      There is no divergence between the tree rings and the post WWII cooling period. There is a divergence between the tree rings and the heavily adjust surface records.

      This is strong evidence that the adjustments to the surface records has reduced their accuracy.

    • The post-2000 temperature spike has no support in the surface temperature record, the radiosonde weather balloon record or the satellite temperature record.

      We know – as do the researchers since they make no reference to any years after 2003. The post 2000 spike is an artifact of the low number of proxies available.

  67. Looking further at the data I see that I made a mistake in my choice of end-points. the number of proxy’s drops off rapidly after 1988, making the results post 1988 unreliable. A few outliers post 1988 will have much more weight than those prior to 1988.

    Using this new information, here is the plot of average and standard deviation during the time when the number of proxies is constant. The hockey stick is gone.

    And just for fun, here is the standard deviation of the whole data series from 750 – 2011. As can be seen from the 30 year moving average there has been no significant change in climate variability during the industrial age. In point of fact, climate was much more volatile prior to the 1500’s. It appears that since the 1500’s we have been in a period of abnormally low climate change.

    • Fred

      The researchers themselves don’t include anything after 2003 in their analysis – or not in the paper at least. They do cite 1994-2003 as being the warmest decade but also state that it is not statistically distinguishable from 1946-55 and 1161-70. They are pushing it a bit by including 1994-2003 as the last complete decade but, leaving that aside, you’re right – there is no hockey stick.

      The reconstruction is not that far removed from our traditional (non-CAGW) understanding of the MWP and LIA.

      • The researchers themselves don’t include anything after 2003 in their analysis
        ================
        I wouldn’t be too sure of this. see ferdberple January 17, 2016 at 4:28 pm

    • Ferd writes:

      It appears that since the 1500’s we have been in a period of abnormally low climate change.

      Not sure I’d based any conclusion or even suggestion on these data Ferd, there are quite a few things other than temperature that could effect tree rings as everyone has said but it’s also true the “calibration” is almost certain to become less and less meaningful as we move further outside of its “region” (well, not certain but at least … oh heck I don’t know what it does and no one else does either but I wouldn’t try making any judgements based on it).

      Last I looked (at the Mann data circa .1998) there wasn’t even documentation on the species of trees used. Do these author’s bother to mention it? This could simply be due to the use of a different species with higher variance? Who knows? It’s all certifiable crap-ola (is there a correct spelling of crap-ola?)

      • +10

        More grist for the mill. Maybe some rebellious science types could create their own version of the anti Nobel Prize for worst science that set the avocation back the most.

        Perhaps call it the Mannkind Prize.

        If you’ve never played with the database that Mann uses google iowahawk. He does a fine job giving u all Mann’s data and helps you do what he did.

        [Perhaps that should be the MannData’ed Prize? The annual Mannipulated Prize? .mod]

  68. Willis, I said this when Brandon wrote about it at Bishop Hill’s thread, isn’t it possible that is is not author’s pushing their own reconstructions for use, but the use of their reconstructions pushing them to become authors?

  69. John Finn January 17, 2016 at 4:17 am Edit

    Willis

    The first problem with this idea is that both high temperatures and low temperatures cause narrow tree rings.

    Indeed. The tree ring growth response to temperature is reckoned to be an upside down U shape, i.e. there is an optimal temperature after which tree ring growth is stunted. Fine – I know all this. However I also know that the temperature range for most regions over the past several centuries is unlikely to be much outside +/- 1 degree. Now it’s possible that the upper range of temperatures has pushed tree growth over the hump in *some* regions but is that going to happen right across the NH at exactly the same period in time.

    Thanks, John. I fear that you are looking at averages. Trees don’t know anything about averages. Instead, they react and respond to instantaneous temperatures.

    And indeed, it is not at all uncommon for instantaneous temperatures to be well above where trees grow well for a part of every day during a hot summer.

    And while (as you point out) the overall average still moves in the right direction, the upside-down “U” shape means that the temperature response is far, far from linear.

    The evidence suggests not. In general, ring widths are wider in the MWP and the modern period than during the LIA years.

    We also know that crop failure and famine were more common in the LIA years – i.e. the years identified by the Wilson study as being cooler than the MWP or recent years. Now that could be because of widespread heat and drought in the NH but I somehow doubt it.

    The question is not the general historical variations. It is whether their temperature scale is a) accurate, and b) precise.

    Providing we understand the limitations of this study I don’t think it’s entirely useless.

    I don’t think the findings that the mid-12th century was about a degree or so warmer than the early 19th century is totally unbelievable.

    The problem, as always, lies in the error bars. In this case, yes, their result is not “totally unbelievable” … but the true error bars go floor to ceiling, so we have no idea whether it is even in the range. So we cannot put weight on any conclusions we might draw from the results.

    Best regards.

    • The question is not the general historical variations. It is whether their temperature scale is a) accurate, and b) precise.

      If that really is “the question” I’d probably agree with you but from a personal perspective I’m simply looking for the timing of climate shifts and how the magnitude of those shifts compare. e.g. was there a MWP, how long did it last and how does it compare with the modern day.

      Rob Wilson writes

      The main aims of N-TREND are to:

      1. provide the wider palaeoclimate community access to a quality controlled data-base of published tree-ring records that express a reasonably robust estimate of local temperatures. These data can then be used in further larger scale compilations and as new records are developed, the N-TREND archive will be updated.

      2. To provide a strategic focus for the dendroclimatic community to identify where research needs to be focused (i.e. updating of old sites, sampling in new locations etc)

      We hope the existence and results of N-TREND will help provide important justification for investment in regions where little tree-ring data currently exist.

      So you could be right about the intentions of the researchers. I don’t know Rob Wilson but the does appear to be very approachable. I don’t know if you feel this is worth following up.

      • John Finn writes:

        If that really is “the question” I’d probably agree with you

        I think it is John but I’ve already said that. What I didn’t do is explain why. In my opinion, this is the camel nose and if I accept it, I loose all ability to criticize any of its conclusions or any speculation drawn from it. The authors don’t acknowledge the in-accuracy of these data with error bars (which would obviously cause the reader to be aware that no conclusions can be reasonably reached from them) and they grossly overstate precision, of which there is exactly none. The gleefully use empirically derived “calibrations” in a fashion proscribed in scientific research. The break every rule and they do it openly and with no criticism from their peers. It’s Junk Science.

        So yes, the question really is “whether their temperature scale is a) accurate, and b) precise” as Willis notes and any degree of acceptance, any use of these data at all should be laughed at and the authors subject to derision by any competent scientist. This activity can’t be tolerated. These people should be shunned; they aren’t scientists.

  70. Rob Wilson (the lead researcher of N-TREND2015) posted this comment at Bishop Hill.

    Hi BH followers
    please read the paper carefully before making comments – it will help you formulate objective criticism.
    All available here: https://ntrenddendro.wordpress.com/
    regards
    Rob

    Rob Wilson is also reported to have made the the following comment in 2005 :

    There has been criticism by Macintyre of Mann’s sole reliance on RE, and I am now starting to believe the accusations

    WUWT readers have been too quick to jump all over this.

    • John, I truly don’t understand your point. You say that Rob Wilson

      • asked people to read their paper, and
      • grudgingly conceded a decade ago that McIntyre was right about Mann’s use of RE.

      What do those have to do with your claim that “WUWT readers have been too quick to jump all over this.”?

      This is a perfect example of why I ask people to quote what they disagree with. You are busting somebody for something you don’t like … but we have no idea either who you are busting for their excess jumping speed, or what they said that convinced you that they are guilty of premature ejumpulation.

      Let me suggest that you stick to the science and leave the vague hand-waving accusations about “WUWT readers” out of it. It just costs you credibility when you resort to that kind of unspecified blanket denunciation.

      In friendship,

      w.

  71. Take a look at the following graphs where I cut the data off in 2011 VS 2003. Look at the 2 year running average. 2011 big hockey stick. 2003 no hockey stick.

    The problem is there are some big outliers in the last couple of years and very few samples, which skews the hell out of the graph.

  72. To me this is the money shot. You are not going to get climate change without a change in variance (STD^2). And there hasn’t been a significant change since about 1500.

    Compare this to around 1300 and the big spike in variance. That should mark real climate change. And sure enough, here is what WP has to say:

    possible beginning of the Little Ice Age:
    1250 for when Atlantic pack ice began to grow
    1275 to 1300 based on radiocarbon dating of plants killed by glaciation
    1300 for when warm summers stopped being dependable in Northern Europe
    1315 for the rains and Great Famine of 1315–1317
    https://en.wikipedia.org/wiki/Little_Ice_Age

  73. John Finn January 17, 2016 at 2:03 am

    … we can probably deduce the climatic conditions of the time from tree rings. Since temperature will be a factor in those conditions we can probably have a reasonable stab at the relative warmth of the MWP and the LIA and the 20th century.

    Everyone’s getting hung up on the accuracy and precision of the proxies and the method used to estimate the anomalies. It’s probably more accurate to think of the anomalies as climate indices.

    Thanks for your thoughts, John. However, it seems that you are not clear on the difference between accuracy and precision. Think of it in terms shooting. Precision means that your shots are tightly grouped, although they may be far from the bullseye. Accuracy means that they are centered around the bullseye, even if the group is scattered. It is possible to be very precise without being all that accurate. The CERES dataset is like that.

    It is also possible to be accurate without being precise—the shots are centered on the target but they are not tightly grouped.

    In this case, we do not know whether the results of the tree ring analysis are either precise or accurate. Now you say that we can use them as “climate indices” … and IF we knew that they were precise, we could do that. We could compare one time period to another.

    But we do not know how precise the results are. As a result, the variations we see may be totally meaningless, and we cannot simply use them as “climate indices” as you suggest.

    For example, a tree could track temperature quite closely … but at some point insects killed off its main competition. After that the tree got more sun and nutrients, so it has wider rings.

    Now, can we say that the latter period with wider rings is warmer than the previous period, even as a “climate index”? I say no.

    Regards,

    w.

    • Thanks for your thoughts, John. However, it seems that you are not clear on the difference between accuracy and precision. Think of it in terms shooting. Precision means that your shots are tightly grouped, although they may be far from the bullseye.

      Willis – I have an honours degree in Mathematics. I know the difference between accuracy and precision.

      • But do the dendroclimatologists? Do they include with their reconstructions a measure of the accuracy of their samples?

        1. Because looking at the N_Trend2015.xls data they are specifying temperature anomalies to 2 decimal places of precision and I very strongly suspect that trees are nowhere near that accurate as thermometers.

        2. Because the dendro community has a practice of filtering (“calibrating”) their samples based on temperature, a practice that is better known mathematically as “selecting on the dependent variable”, which is a forbidden practice because it leads to spurious correlations. Here is the basic problem:

        problem: solve: temperature = function (tree rings)

        filter tree rings based on temperature

        now the problem becomes: solve: temperature = function (tree rings, temperature)

        and the simplest solution is: temperature = 0 * tree rings + 1 * temperature

        therefore: any value of tree rings will work, regardless of whether they are matching temperature because they are sensitive to temperature, or simply matching due chance combinations of other factors.

        therefore, filtering trees by temperature is a forbidden practice, because it will lead to spurious correlations. it will amplify false positives, while hiding the number of false positives.

        Unfortunately the dendro community has apparently failed to understand the problem mathematically and continue to “calibrate” their samples. The other soft sciences now recognize the problem and have a great many papers written on the problem and how it leads to false conclusions.

    • For example, a tree could track temperature quite closely … but at some point insects killed off its main competition. After that the tree got more sun and nutrients, so it has wider rings.

      But how much will this impact on the whole NH?

      Willis, this study is not the whole story. It’s a piece of the jigsaw. Hubert Lamb produced a reconstruction of NH temperatures over the past millennium which, as far as I can tell, was based mainly on the Central England Temperature record and some weather records from neighbouring countries. Lamb thought there was a strong enough correlation between NH and CET temperatures to justify this To be fair the CET and NHT are fairly well correlated but this doesn’t mean they move in lock step over all time periods. Despite it’s uncertainties Lamb’s reconstruction was accepted by the climate community for several decades.

      But like Wilson et al, Lamb’s work was just another part of the puzzle. Craig Loehle has provided another independent reconstruction which lends weight to the theory that there was a warm MWP period a cool LIA and a warmer modern period.

      Rob Wilson does appear to acknowledge shortcomings with the TR database since he writes

      We hope the existence and results of N-TREND will help provide important justification for investment in regions where little tree-ring data currently exist.

      And this

      To provide a strategic focus for the dendroclimatic community to identify where research needs to be focused (i.e. updating of old sites, sampling in new locations etc)

      By the way, I’d be interested to know if there are any past 1000 year reconstructions which you consider do have a satisfactory standard of accuracy.

  74. Why do dendro series not include some measure of accuracy?

    For example, say we collected 100 tree ring samples from an area in which we also had temperature data. If we then did a correlation and only 10% of the trees had good correlation and 90% did not, we would know the trees were useless proxies.

    The problem in climate science is that they throw away the 90% that don’t correlate and keep the 10% that do, not stopping to think that the 90% that don’t correlate are telling you that 9 out of 10 trees in the 10% that do correlate are simply doing so by chance.

    Even though 10% correlated, only 1 trees out of 100 is actually correlating because of temperature. the other 9 are doing so by chance. But you have no idea which one is correlating, and when you lump it in with the 9 that are not, you are going to get a whole raft of bogus conclusions.

  75. John Finn January 18, 2016 at 2:56 am

    Thanks for your thoughts, John. However, it seems that you are not clear on the difference between accuracy and precision. Think of it in terms shooting. Precision means that your shots are tightly grouped, although they may be far from the bullseye.

    Willis – I have an honours degree in Mathematics. I know the difference between accuracy and precision.

    Thanks, John, and my congratulations on your honours degree. That being the case, consider the following:

    A temperature reconstruction without believable error bars and without any mention of the inherent uncertainties in the underlying proxies says that since the year 2000 the northern hemisphere summers have warmed at a rate of 4° per century …

    Is that reconstruction precise enough for us to use as a “climate index”? Because that is what you are claiming, and I don’t see any mathematical foundation for that claim.

    Me, I say any reconstruction that gets it that wrong, and with such unbelievable error bars, is far from precise enough to use as an index of anything but the hubris of the authors … what says your honours degree?

    Next, consider the following scenario. We pick 53 actual temperature records from around the northern hemisphere, including several “area-averages” of temperature records covering regional areas.

    Then, regardless of whether they are single thermometer records or area averages, we normalize them all to a common period.

    Then we average the normalized records, and we fit them using linear regression to the actual temperature record. Finally, we throw away the underlying temperature records, and we present only the normalized records and their average, which we claim is the temperature history of the northern hemisphere.

    What does your honours degree say about the uncertainties inherent in this process, even if the underlying data is actual thermometer records? How does including the area averages on the same footing with the individual temperature records affect the uncertainties?

    Finally, what if the underlying data is NOT thermometers, but tree-ring records which are known to be subject to a host of confounding factors. They are averages of varying numbers of trees in varying locations in unknown historical conditions.

    What do you think are the uncertainties in that normalize-and-average process, particularly given that the trees were selected by different authors using different criteria, and that many other tree ring records exist that they did not use?

    Their claim is that they can tell the temperature a thousand years ago to within a degree or so … but if you look at their Figure 2 panels D and E, you’ll see that the actual temperature a mere hundred and fifty years ago is already outside their wildly unrealistic error estimates …

    And if their reconstruction is already in error pushing towards 1°C only 150 years ago, how much is it out when we look a thousand years back in time?

    The ugly truth is … we don’t know.

    I describe this type of situations as having “error bars that go from floor to ceiling”, and I hold that it makes the results worse than useless for anything including relative comparisons and “climate indices”, as they can be actively misleading.

    Best regards,

    w.

    • Thanks Willis
      Once again you do a good job zeroing in on the overreach.

      Dendroclimatologists probably don’t like being told that their field lacks the necessary level of precision and accuracy for the claims they make. Sometimes I imagine the various science fields as little hatchlings in a nest .. squawking and chirping for attention from the various mamma birds that feed them.

    • Thanks, John, and my congratulations on your honours degree.

      About 30 years ago now, Willis, but thanks all the same.

      I’ll tell you want I’m going to do Willis. I’m going read the paper fully and then read your post again. You might ask why I haven’t done this already but my comments were originally in response to other readers – not necessarily to you,

      The ugly truth is … we don’t know.

      Looking at this study in isolation – agreed. But the key features of the reconstruction as described in the paper suggest the estimated values are reasonably well correlated with other non-TR reconstructions. Whatever the reservations about the uncertainties if, to use your analogy, all the shots are clustered around the bullseye, it’s likely to be more than random luck at play. However, having looked closer at the data the correlations are not quite as impressive as I was led to believe by the paper (my fault – not Wilson’s) .

  76. This post is terrible. Most troubling is the fact it says a number of things that are completely and utterly false. For instance, the author asks a number of rhetorical questions like:

    But since that is the case, since they are depending on their own prior transformation of a record of, e.g., tree ring width in mm into an estimated temperature in degrees C, then why on earth would they convert it out of degrees C again, and then at the end of the day convert it back into degrees C? What is the gain in that?

    Which are absurd given the fact the data used in this paper was not originally in temperature units. The idea that all the data used was originally in temperature units, emphasized by the author modifying a quote from the paper to add the word “temperature” to it:

    This strategy explicitly incorporates the expert judgement the original authors used to derive the most robust [temperature] reconstruction possible from the available data at that particular location.

    Is a total fabrication on the author’s part. Had he put any effort into understanding the paper’s data, he’d have known most (if not all) of the series were not originally given in temperature units. Instead, he made this wildly inaccurate claim and people… just believed him.

    The author of this post had no idea what he’s talking about, and it’s embarrassing this post was ever published. I’m a few days late to discovering the post so I don’t know that anyone will see this comment, but if they do, I encourage them to read the post I wrote detailing a number of glaring errors this post contains. That would be better than me rewriting it all here.

    In the meantime, I want to say it’s incredibly sad this terrible post written without any real understanding of what it discusses has been promoted and embraced by this site’s readers.

    • Brandon S? (@Corpus_no_Logos) January 22, 2016 at 2:42 am

      … The idea that all the data used was originally in temperature units, emphasized by the author modifying a quote from the paper to add the word “temperature” to it:

      This strategy explicitly incorporates the expert judgement the original authors used to derive the most robust [temperature] reconstruction possible from the available data at that particular location.

      Is a total fabrication on the author’s part. Had he put any effort into understanding the paper’s data, he’d have known most (if not all) of the series were not originally given in temperature units. Instead, he made this wildly inaccurate claim and people… just believed him.

      Brandon, the reason that they believed my claim is because it is true. From the paper, emphasis mine:

      For N-TREND, rather than statistically screening all extant TR chronologies for a significant local temperature signal, we utilise mostly published TR temperature reconstructions (or chronologies used in published reconstructions) that start prior to 1750.

      You see the part about how they mostly used published temperature reconstructions and not tree ring chronologies, JUST LIKE I HAD SAID? Do you see that it is totally contrary to your claim, and supports my claim entirely?

      Sheesh … my suggestion would be, do your homework before getting all snarky. You don’t look all that attractive with egg on your face.

      w.

  77. Willis Eschenbach, you just misrepresented the quote you claim proves me wrong in a glaringly obvious manner. You say:

    You see the part about how they mostly used published temperature reconstructions and not tree ring chronologies, JUST LIKE I HAD SAID? Do you see that it is totally contrary to your claim, and supports my claim entirely?

    But the quote clearly says:

    we utilise mostly published TR temperature reconstructions (or chronologies used in published reconstructions) that start prior to 1750.

    A paper saying they mostly used published temperature reconstructions or tree ring chronologies does nothing to say the authors “mostly used published temperature reconstructions and not tree ring chronologies.”

    You can mock me and talk about me supposedly getting egg on my face, but when your rebuttal consists of nothing but misrepresenting a quote in a way anyone with basic reading skills would see through…

    • Brandon, here was your claim about me:

      Had he put any effort into understanding the paper’s data, he’d have known most (if not all) of the series were not originally given in temperature units.

      You don’t seem to understand what’s going on in the study. I went over their data with a fine-toothed comb prior to writing the head post. As a result, I knew what you seem to want to misrepresent—70% of their data is from tree ring reconstructions in temperature units, as was clearly implied in the quote I gave you and as is detailed in the study. Go and count them yourself if you don’t believe me.

      w.

      • Willis you are talking to a brick wall. He’s convinced that a “tree ring chronology” is made of tree rings, and not a chronology taken from tree rings and turned into temperature units. Which of course is idiotic. I’m not sure what a chronology made of tree rings would actually look like…maybe something like this? hehehehe

      • Hold on Willis Eschenbach, before we can go any further we need to address the fact you grossly misrepresented that quote. You said:

        You see the part about how they mostly used published temperature reconstructions and not tree ring chronologies, JUST LIKE I HAD SAID? Do you see that it is totally contrary to your claim, and supports my claim entirely?

        While providing a quote which clearly did not say that, as it said:

        we utilise mostly published TR temperature reconstructions (or chronologies used in published reconstructions) that start prior to 1750.

        There was no part saying “they mostly used published temperature reconstructions and not tree ring chronologies.” You made that up. Their comment about what they “mostly” used had nothing to do with the relative proportion of tree ring chronologies to temperature reconstructions. Because of that, nothing about that quote was “totally contrary” to what I had said. You can’t just walk that misrepresentation back and pretend all you had ever said was that it “was clearly implied” by the quote I am wrong.

        You had even bolded the phrase “temperature reconstructions” as though the simple mention of the phrase proved you right. You didn’t say a word acknowledging the use of tree ring chronologies until after I pointed out you had misrepresented the quote, at which point you began to try to play with semantics to pretend you hadn’t said anything wrong.

        If you want to talk about the relative proportions of tree ring chronologies to temperature reconstructions in the data set, we can, but not if you’re just going to constantly misrepresent what gets said. It’s like how I’ve already shown you’ve misrepresented the methodology used by this paper because you didn’t understand it. Arguing the specifics of data isn’t going to work out well if that’s the pattern of behavior you’re going to engage in. If you’re just going to misrepresent everything anyway…

      • Aphan:

        Willis you are talking to a brick wall. He’s convinced that a “tree ring chronology” is made of tree rings, and not a chronology taken from tree rings and turned into temperature units. Which of course is idiotic.

        This is a bizarre comment. Anyone who is remotely familiar with anything related to temperature reconstructions should know a tree ring chronology is not given in temperature units. It may be converted into temperature units via some process, perhaps after being combined with other chronologies, but it is not a teperature record on its own. In fact, many tree ring chronologies don’t reflect temperature at all, but are used to try to measure other things, like precipitation. In the same way, reconstructions are not inherently or necessarily temperature reconstructions.

        I don’t know why you think it is idiotic to say this. It’s trivially easy to see it is true. Just looking at tree ring chronologies is enough to show it as they’re not given in temperature units.

  78. Brandon, I’d said:

    So to summarize the whole process: for most of the data used, it started out as various kinds of proxies (ring width, wood density, “Blue Intensity”).

    Then it was transformed using the “expert judgement of the original authors” into temperature estimates in degrees celsius.

    You said no, it wasn’t true that most of the data had been transformed into temperature estimates, claiming that:

    … most (if not all) of the series were not originally given in temperature units.

    So I went and counted. 70% of the data, which is to say most of the data, had been transformed into temperature units, JUST AS I HAD SAID.

    Rather than deal with your obvious error and admit that you hadn’t done your homework, now you want to whine about something totally different. This time you point out that I’d quoted what they said, viz:

    … we utilise mostly published TR temperature reconstructions (or chronologies used in published reconstructions) that start prior to 1750.

    I had interpreted that as meaning that mostly they used published temperature reconstructions, plus for some lesser number, they used chronologies. And in fact when I counted, that turned out to be the case. So it seems that one of us could read simple English and intuit the authors’ meaning.

    Somehow, you still want to claim that I was wrong, and that what they meant was something different … sorry, Brandon. You are entitled to your own interpretations, but you don’t get your own facts.

    And at the end of the day, other than as a spectacularly unsuccessful attempt to bite my ankles on some minor issue, it;s not clear what you were trying to accomplish. I mean, suppose you had been 100% right instead of being totally wrong … what difference would that make? Whether the data was temperatures or not is a very minor issue, given the other huge problems in the study … so what on earth were you trying to prove?

    I ask because all you’ve proven so far is that you didn’t do your homework, and I’m curious what it was you thought you’d originally set out to show, and why it’s important.

    Regards,

    w.

    • Willis Eschenbach:

      So I went and counted. 70% of the data, which is to say most of the data, had been transformed into temperature units, JUST AS I HAD SAID.

      You might want to recount. As I point out below, there is no way 70% of the series had been transformed into temperature data. Of the series used by the authors, 33/54 never existed in temperature units. I don’t know how you came up with your count (I offered one guess in that comment), but it’s not a good one.

      I had interpreted that as meaning that mostly they used published temperature reconstructions, plus for some lesser number, they used chronologies. And in fact when I counted, that turned out to be the case. So it seems that one of us could read simple English and intuit the authors’ meaning.

      Leaving aside that your count was wrong, your interpretation of the quoted sentence is completely nonsensical. Nobody would ever say they mostly used X (or Y) data to indicate most of their data was of type X. The phrase “mostly published” was obviously a reference to the fact not all of the series used by the authors were taken from published work.

      If you want to focus on semantics to try to pretend you didn’t misrepresent the quoted text, you can, but nobody who “could read simple English and intuit the authors’ meaning” would ever agree with your interpretation.

      And at the end of the day, other than as a spectacularly unsuccessful attempt to bite my ankles on some minor issue, it;s not clear what you were trying to accomplish. I mean, suppose you had been 100% right instead of being totally wrong … what difference would that make? Whether the data was temperatures or not is a very minor issue, given the other huge problems in the study … so what on earth were you trying to prove?

      I said this post had many mistakes, giving one example from the number I had written about. Claiming that one example doesn’t matter while ignoring the other glaring errors I pointed out seems rather disingenuous. If you actually wanted to know why I think your mistakes matter, you should have addressed the fact I’ve said things like you’ve failed to understand the paper’s methodology in a drastic way and consequently created a false comparison to criticize it.

      But sure, pretend I’m just trying to “bite [your] ankles.” That level of response to critics is bound to convince… your fanboys, I guess? I’m not sure who else would fail to notice your pathetic rhetorical flourishes serve only to divert attention from the fact you don’t address what has been said.

  79. While I think the relative number of tree ring chronologies compared to temperature reconstructions used by this paper is a minor issue, having picked it as an example of the many problems I listed in the post I wrote merely because of its simplicitly, I suppose it would help to resolve it. In that vein, I should point out there is perhaps a bit of a translation problem, so to speak. Willis Eschenbach’s latest comment says:

    You don’t seem to understand what’s going on in the study. I went over their data with a fine-toothed comb prior to writing the head post. As a result, I knew what you seem to want to misrepresent—70% of their data is from tree ring reconstructions in temperature units, as was clearly implied in the quote I gave you and as is detailed in the study. Go and count them yourself if you don’t believe me.

    Now, I actually understand what is going on in this study better than Eschenbach does. One can tell this by the fact I was able to accurately describe its methodology in my post, demonstrating this post has screwed things up by taking (the average of) output of one step of the methodology and comparing it to the final results given by the methodology as proof the methodology has little effect. Of course, that’s silly. You can’t tell how much effect a methodology has by comparing the output of Step 1 to the output of the final results. You have to compare the final results to what would have happened without any of the steps, including Step 1.

    But that remark was rhetorical, not informative. What’s actually informative is Eschenbach’s claim “70% of their data is from tree ring reconstructions in temperature units.” This statement would seem strange to anyone who has simply read the Supplementary Information provided by the authors. Table A1 of that document explicitly lists 33 series as chronologies, 20 series as reconstructions and doesn’t explicitly state what 1 series is. 20/54 is obviously not ~70%. It’s ~35%.

    That’s a pretty big discrepancy. There may, however, be a simple explanation. You see, 18 of these series come from the PAGES 2K Asian network. These series are listed by the authors as chronologies, not temperature reconstructions. They are series created by looking at the PAGES 2K Asian results in 6 by 8 degree gridcells. They are not in temperature units, and they were never given in temperature units by anyone.

    But there’s a catch which might explain Eschenbach’s remark. The PAGES 2K Asian results were not originally given in 6 by 8 degree gridcells. They were originally given in 2 by 2 degree gridcells. At that point, they were given in temperature units. When these results were reduced to 6 by 8 degree gridcells, they were converted into unitless series to prevent issues like baseline/variance differences in the finer results introducing biases into the series used for this paper. Perhaps Eschenbach feels this conversion should be ignored when talking about whether the underlying series were given in temperature units or not.

    I can’t say that’s necessarily wrong. It is, however, a nuanced argument which requires one not simply look at whether the series used by the authors of this paper are given as tree ring chronologies or temperature reconstructions, but also whether or not the series underwent any processing steps between the original paper they were created with and the methodology used in this paper. It would be unreasonable to expect anyone to realize he intended his argument to be based on such nuances given he never said a word to indicate they exist. How he could ever imagine people would realize 33/54 series explicitly being labeled tree ring chronologies by the authors of this paper should be considered as indicating 70% of the data is given as temperature reconstructions, not tree ring chronologies, is beyond me. I certainly don’t regret saying:

    Had he put any effort into understanding the paper’s data, he’d have known most (if not all) of the series were not originally given in temperature units.

    At the time I wrote the comment, I knew well over half the series had never been given in temperature units, so that comment was perfectly reasonable. Now that I have counted the series like Eschenbach suggested I do if I didn’t believe him, I find 33 of 54 series were never given in temperature units. That… only confirms what I said. I have no idea why Eschenbach suggested I count the series as anyone who does will find I was completely correct.

    Maybe there are some nuances which make Eschenbach’s comments here not completely wrong, but if so, he never even hinted at them.

  80. Brandon S? (@Corpus_no_Logos) January 22, 2016 at 10:19 pm

    Willis Eschenbach:

    So I went and counted. 70% of the data, which is to say most of the data, had been transformed into temperature units, JUST AS I HAD SAID.

    You might want to recount. As I point out below, there is no way 70% of the series had been transformed into temperature data. Of the series used by the authors, 33/54 never existed in temperature units. I don’t know how you came up with your count (I offered one guess in that comment), but it’s not a good one.

    Hey, when you don’t know what I’ve done, why not just ask? I’m happy to explain.

    Here’s what I did. I looked at the list given by the authors as Appendix A in the Supplementary Online Information, wherein every proxy is listed as either a temperature reconstruction, or a chronology.

    I have no clue why you think that 33 out of the 54 “never existed in temperature units”. You may be mistaking the various different proxies represented in the ASGrid gridded data for chronologies. They are not. The ASGrid gridded data are described in Appendix A as being created from a “2×2 gridded reconstruction:”.

    Here are the results of the 54 datasets, according to Appendix A

    GOA, Recon.
    ICE, Recon.
    FIRT, Chron.
    IDA, Recon.
    THE, Chron.
    COP, Chron.
    WRAx, Chron.
    IBC, Recon.
    YUN, Recon.
    YUS, Recon.
    NTR, Chron.
    QUEw, Recon.
    QUEx, Chron.
    NQU, Chron.
    LAB, Recon.
    Efmean, Recon.
    YAM, Chron.
    ALPS, Recon.
    SFIN, Recon.
    JAEM, Recon.
    ASGrid1, Recon.
    KOL, Recon.
    ASGrid2, Recon.
    POLx, Chron.
    ASGrid10, Recon.
    ASGrid11, Recon.
    SCOT, Recon.
    FORF, Chron.
    TAT, Recon.
    TYR, Chron.
    TAA, Chron.
    PYR, Recon.
    MOG, Recon.
    KYR, Recon.
    TAY, Chron.
    ALT, Chron.
    ASGrid3, Recon.
    ASGrid12, Recon.
    ASGrid4, Recon.
    ASGrid5, Recon.
    ASGrid6, Recon.
    OZN, Recon.
    ASGrid13, Recon.
    ASGrid7, Recon.
    MANx, Chron.
    YAK, Chron.
    ASGrid14, Recon.
    ASGrid15, Recon.
    ASGrid16, Recon.
    ASGrid8, Recon.
    ASGrid17, Recon.
    ASGrid9, Recon.
    ASGrid18, Recon.
    NJAP, Recon.

    That is a total of 38 out of 54 which are reconstructions, or 70.3% …

    I gotta say, though, that you manage to focus on to trivialities … suppose you were right about this issue. It would make no difference to either my analysis or my conclusions. So I fail to understand your obsession with this question.

    w.

    • His obsession is with “winning” a point for his side, even if it’s the most trivial, stupid, irrelevant point he can find. The fact that he just wrote 8ish paragraphs about that one, tiny, trivial point and the way he says things indicates that his pride is at stake and he will most likely continue to bring this up even if he’s wrong. Willis, your patience is amazing.

    • Willis Eschenbach:

      Hey, when you don’t know what I’ve done, why not just ask? I’m happy to explain.

      Here’s what I did. I looked at the list given by the authors as Appendix A in the Supplementary Online Information, wherein every proxy is listed as either a temperature reconstruction, or a chronology.

      I have no idea why you’d think I should ask you what you did when you clearly counted the series. The only question is how you came up with a number so different from mine – which I managed to accurately explain without having asked you anything. You just showed my interpretation of what you did was completely correct so… why would I ask you what you did?

      I have no clue why you think that 33 out of the 54 “never existed in temperature units”. You may be mistaking the various different proxies represented in the ASGrid gridded data for chronologies. They are not. The ASGrid gridded data are described in Appendix A as being created from a “2×2 gridded reconstruction:”.

      While the ASGrid series are stated to be derived from a reconstruction, it is also explicitly stated they are not in temperature units. They never were. That’s why the authors label the series: “RW and MXD chronologies,” not reconstructions. I already explained this in the comment right above yours, yet you somehow managed to ignore everything I said about the issue while insisting I’m wrong about it.

      I gotta say, though, that you manage to focus on to trivialities … suppose you were right about this issue. It would make no difference to either my analysis or my conclusions. So I fail to understand your obsession with this question.

      Dear god, I don’t know how you could be more disingenuous. My first comment here referred to there being multiple errors in this post, and I’ve pointed out you’ve done nothing to address most of the errors I highlighted. I’ve specifically pointed this out to you, telling you you ought to address the many things I’ve said rather than focusing solely on this one example.

      Yet here you are, claiming I am obsessed with this question. I’m the one who said we should be looking at other issues, not just this one. You’re the one who has refused to do anything but focus on this one issue. In what world does that make me the one obsessed with this issue? This is like having the exchange:

      “There are many errors in this post. We should look at them all, but here is one example.”
      “No. We must only discuss this one example. I won’t look at any of the others. Dear god, why are you so obsessed with this one example?”

      But it doesn’t matter. You’re clearly not even trying to respond to what I say. You just wrote this entire comment of yours while flagrantly ignoring the fact everything it says has already been addressed in the comments I’ve written. That’s why I said we shouldn’t bother to move onto other issues if we couldn’t resolve your ridiculous misrepresentation of what the paper said – because you’re serially incapable of accurately treating anything you disagree iwth.

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