Continuing Problems with Paleoclimate Proxies

Discussion in 'Environment & Conservation' started by Jack Hays, Jan 11, 2021.

  1. Jack Hays

    Jack Hays Well-Known Member Donor

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    The litany of shoddy paleoclimate work seems endless.
    PAGES19 Asian Tree Ring Chronologies
    Aug 15, 2021 – 3:25 PM
    About 20% of the PAGES 2019 proxies are 50 Asian tree ring chronologies, all of which were originally published as chronologies in PAGES (2013). At the time, none of these series (and certainly not in these digital versions, had ever been published in technical literature, peer reviewed or otherwise. Nothing in the Supplementary Information to any of these articles says who calculated these chronologies or how they were calculated. PAGES (2017) does cite a couple of academic articles (especially Cook et al 2013) for many of these series, but none of these chronologies actually appears in any of these academic articles or their supplementary information.

    PAGES (2013) was originally rejected by Science in 2012, because peer reviewers (including Michael Mann) objected to the introduction of so many new proxies in what was ostensibly a review paper; they sensibly recommended that components first be peer reviewed in relevant specialist journals. However, PAGES2K results had already been incorporated into a pending IPCC assessment (AR5), so the authors, now under a very short deadline, submitted to Nature, which was confronted by the same review problems that led to the rejection by Science. Keith Briffa had a clever, too clever, solution: publish the PAGES2K submission as a “Progress Article” – a classification that did not require the peer review procedure required for a Research Article. This would qualify the article for IPCC and nobody would notice the sleight-of-hand. (Even I didn’t notice it at the time; someone told me.)

    One of the consequences of the 2013 maneuvering was that several hundred Asian tree ring chronologies were introduced to paleoclimate archives with no technical publication or technical peer review, no information on how they were calculated or even who among the PAGES2K (2013) authors had calculated them. . . .
     
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  2. Jack Hays

    Jack Hays Well-Known Member Donor

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    Errors in paleoclimate proxies follow one rule: the more you look the more you find. Some practitioners thrive by replicating those errors.
    PAGES19: 0-30S
    Sep 2, 2021 – 3:07 PM
    In a Climategate email. Keith Briffa famously sneered at Michael Mann’s claim that a temperature reconstruction could represent a hemisphere, including the tropics, by regressing a “few poorly temperature respresentative tropical series” against “any other target series” – even the trend of Mann’s own “self-opinionated verbiage” as follows:

    I am sick to death of Mann stating his reconstruction represents the tropical area just because it contains a few (poorly temperature representative ) tropical series. He is just as capable of regressing these data again any other “target” series , such as the increasing trend of self-opinionated verbage he has produced over the last few years , and … (better say no more)

    People frequently say that the PAGES2K reconstruction has “vindicated” Mannian reconstructions – but neglect to mention that PAGES2K similarly regressed a “few poorly temperature representative tropical series” onto an increasing trend – thus, repeating, rather than vindicating, (one of) Mann’s erroneous methodologies.

    In today’s article on the Hockey Stick featured in the new IPCC Hockey Stick diagram, I’ll look at proxies in the southern tropics (0-30S latband). The proxy network turns out to be defective in bizarre, unexpected ways, not reported on or discussed in the original article. . . . .
     
  3. Sunsettommy

    Sunsettommy Well-Known Member

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    Reading the comments shows how devastating Biffa's attack on Mann's bogus claims.

    How in the world do people still think the H.S. paper is valid, it must be the vapors.......
     
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  4. Jack Hays

    Jack Hays Well-Known Member Donor

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    Their loyalty is tribal.
     
  5. Jack Hays

    Jack Hays Well-Known Member Donor

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    Yet again the proxies don't support the narrative.
    PAGES 2019: 0-30N Proxies
    Sep 15, 2021 – 12:01 PM
    Next, the PAGES2019 0-30N latband. Their CPS reconstruction (CPS) for the 0-30N latband (extracted from the global reconstruction) looks almost exactly the same as reconstructions for the 0-30S and 30-60S latbands. However, none of the actual proxies in this latband look remotely like the latband reconstruction, as I’ll show below. In the course of examining the proxies in this latband, I looked back at 0-30N latband in prior PAGES compilations (2013 and 2017) and Mann et al 2008. The evolution of the proxy network is quite fascinating: the most notable feature is the increasing dominance of short (1-200 year) coral series in a network supposedly reconstructing the past 2000 years.

    [​IMG]
    PAGES2019 Proxies with Values Prior to AD1200

    The primary purpose of “2000 year” proxy reconstructions of temperature is to compare modern temperature to estimates of medieval and first millennium temperatures. There are 41 proxies in the 0-30N network, but only three proxies with values before AD1200 and only one (!?!) proxy with values prior to AD925 (see diagram below).

    The single long proxy with values through the first millennium is a temperature reconstruction from Mg/Ca values from an ocean core offshore northern Africa. Its values decline erratically through the past two millenia, with very minor recovery in 20th century. If this is the ONLY data for the 0-30N latband through most of the first millennium, how can PAGES2K say with any confidence that modern values are higher than first millennium values? They can’t. My guess is that their algorithm(s) somehow paste 20th century trends in coral d18O onto non-descript or declining long proxies, but that is, at present, just a surmise. All one can say for sure is that, based on the PAGES2019 0-30N proxy network, it’s impossible to assert that modern temperatures in this latband exceed first millennium values (or vice versa.) . . .
     
  6. Jack Hays

    Jack Hays Well-Known Member Donor

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    The infamous Hockey Stick is the principal symbol of problems with paleoclimate proxies.
    The Decline, the Stick and The Trick – Part 1
    Nov 2, 2021 – 12:45 PM
    One of the central claims of The Trick, if not the most central claim, was that “hiding the decline” was nothing more than an inopportune phrase about a single diagram.

    It wasn’t.

    The “trick to hide the decline” was an inopportune, if revealing, phrase, but rather than the issue being limited to a single diagram, the inconsistency between the Decline (in observed tree ring widths and densities) and the Hockey Stick temperature reconstructions (primarily based on tree ring widths) was, together with the looting of the Baghdad Museum, the issue that inspired my original examination of Michael Mann’s Hockey Stick and was the driving theme of Climate Audit from its origin up to Climategate. There are dozens, even hundreds, of Climate Audit articles that, in one way or another, relate back to the conundrum arising from the inconsistency of the underlying proxies and the superficial consistency of the reconstructions.

    In this and a couple of follow-on articles, I’ll illustrate the centrality of The Decline vs The Stick in the controversies in the years prior to Climategate. For the benefit of people that may be new to these disputes, I re-iterate that I never interpreted the late 20th century decline in ring widths as evidence of a decline in temperatures, but as a seriously problematic inconsistency for “reconstructions” relying in large part on tree rings. . . .
     
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  7. Jack Hays

    Jack Hays Well-Known Member Donor

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    The proxies are arguing with each other.

    Climate Past Far From Settled: 7 Major Temperature Reconstructions Find No Agreement

    By P Gosselin on 29. March 2022

    Share this...
    A new paper published in open access publishing MDPI looks at seven prominent hemispheric and global temperature reconstructions for the past 2000 years (T2k).

    [​IMG]

    The analysis conducted by the authors found that some reconstructions “differed from each other in some segments by more than 0.5 °C” whilst some show negligible pre-industrial climate variability (“hockey sticks”).

    Those showing variability would suggest natural factors playing a greater role than those that claim climate had been rather constant over the past 2000 years. . . .
     
  8. Bowerbird

    Bowerbird Well-Known Member

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    Same old same old :roll:
     
    Last edited: Mar 30, 2022
  9. Jack Hays

    Jack Hays Well-Known Member Donor

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    I guess research is tedious for those who prefer orthodox doctrine.
     
  10. Jack Hays

    Jack Hays Well-Known Member Donor

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    From the paper linked in #107:
    [​IMG]
    Figure 1. Comparison of the seven T2k composites. Anomaly refers to 1961–1990 temperature average. Smoothing filters: 40 years for MM99 and MM08, 30 years for LJU10, PA13, PA19, and BÜ20.
     
  11. Sunsettommy

    Sunsettommy Well-Known Member

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    Yup your lack of counterpoints is the same old which means you don't know if the article is good or not.

    :donut:
     
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  12. Bowerbird

    Bowerbird Well-Known Member

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    Come on! Why should I bother spending hours of my time researching and counter arguing what is essentially a “cut and paste” only to have the denialist chorus line on this forum dismiss all that work out of hand. The bottom line though is that this sort of disagreement is part of the scientific process as paleo climatology is far from settled. The paper will be reviewed, discussed and, if the finding are found to be robust, incorporated into the exisiting knowledge base
     
  13. Bowerbird

    Bowerbird Well-Known Member

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    I will put the exact same amount of effort into this as you do
     
  14. Jack Hays

    Jack Hays Well-Known Member Donor

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    No one dismisses your "work." Insults and name-calling are another matter.
     
  15. Jack Hays

    Jack Hays Well-Known Member Donor

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    That is demonstrably false.
     
  16. Bowerbird

    Bowerbird Well-Known Member

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    Sorry - you are right

    I put in lots more effort and I am happy to put up a bet to prove that
     
  17. Jack Hays

    Jack Hays Well-Known Member Donor

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    Also demonstrably false.
    I never wager.
     
  18. bringiton

    bringiton Well-Known Member

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    No. The more robust the paper's findings are determined to be, the more effort will be devoted to contriving some means to exclude them from the knowledge base. We've already seen that often enough.
     
  19. Bowerbird

    Bowerbird Well-Known Member

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    Sooooooo - how often have you read the IPCC reports? How about our latest cut and paste? What is YOUR a evaluation of the research findings in relation to the accepted current accepted knowledge? In other words how does THIS paper deviate from the IPCC and what is the projected impact on the IPCC modelling and recommendations?
     
  20. Bowerbird

    Bowerbird Well-Known Member

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    Nice little conspiracy theory you have going there

    Now exactly who will be putting in that effort?
     
  21. Jack Hays

    Jack Hays Well-Known Member Donor

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    We have already the IPCC discussion. You were surprised I was up to date.
    The paper's abstract answers your questions comprehensively.

    Global mean annual temperature has increased by more than 1 °C during the past 150 years, as documented by thermometer measurements. Such observational data are, unfortunately, not available for the pre-industrial period of the Common Era (CE), for which the climate development is reconstructed using various types of palaeoclimatological proxies. In this analysis, we compared seven prominent hemispheric and global temperature reconstructions for the past 2000 years (T2k) which differed from each other in some segments by more than 0.5 °C. Whilst some T2k show negligible pre-industrial climate variability (“hockey sticks”), others suggest significant temperature fluctuations. We discuss possible sources of error and highlight three criteria that need to be considered to increase the quality and stability of future T2k reconstructions. Temperature proxy series are to be thoroughly validated with regards to (1) reproducibility, (2) seasonal stability, and (3) areal representativeness. The T2k represents key calibration data for climate models. The models need to first reproduce the reconstructed pre-industrial climate history before being validated and cleared for climate projections of the future. Precise attribution of modern warming to anthropogenic and natural causes will not be possible until T2k composites stabilize and are truly representative for a well-defined region and season. The discrepancies between the different T2k reconstructions directly translate into a major challenge with regards to the political interpretation of the climate change risk profile. As a rule of thumb, the larger/smaller the pre-industrial temperature changes, the higher/lower the natural contribution to the current warm period (CWP) will likely be, thus, reducing/increasing the CO2 climate sensitivity and the expected warming until 2100.
     
  22. Bowerbird

    Bowerbird Well-Known Member

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    Lols! I thought you would bow out with another cut and paste

    Hardly an attempt to research
     
  23. Jack Hays

    Jack Hays Well-Known Member Donor

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    It's a topic I know well. That's why I started this thread.
    With some work you might get up to speed.
     
  24. bringiton

    bringiton Well-Known Member

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    The climategate emails proved it is more than a theory.
    I'm sure you can count on Michael Mann, Phil Jones, Gavin Schmidt, James Hansen, etc. -- you know: the usual liars.
     
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  25. bringiton

    bringiton Well-Known Member

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    I see. So, you just reread them over and over again, like a catechism. That explains a lot.
     
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