Mann's tree ring proxy train wreck

Eric Worrall writes: Mann’s thermometer spliced hockey stick has taken even more damage in the last few days, with Steve McIntyre helpfully providing reconstructions based on tree rings which demonstrate how, without the benefit of Mike’s scientifically dubious “nature trick”, the hockey stick simply disappears – tree rings demonstrably don’t correlate with temperature.

salzer-2014_figure-5

Figure 1. Salzer et al 2014 Figure 5, showing treeline north-facing (NFa -blue) and south-facing (SFa -red) chronologies for 1980-2009. This information was digitized for use in Figure 2 comparisons.

According to McIntyre;

The new information shows dramatic failure of the Sheep Mountain chronology as an out-of-sample temperature proxy, as it has a dramatic divergence from NH temperature since 1980, the end of the Mann et al (and many other) reconstructions.  While the issue is very severe for the Mann reconstructions, it affects numerous other reconstructions, including PAGES2K.”

http://climateaudit.org/2014/12/04/sheep-mountain-update/

What is worse, in my opinion, is that Mann and Briffa can’t even claim they weren’t warned. As early as 1998, the very Russian Scientists who Briffa hired to collect the tree ring samples, tried to alert Briffa that the samples didn’t show what they wanted them to show. The difference is, the Russians weren’t measuring tree ring width, their favoured metric was the polar timberline – the northernmost edge of the great Arctic forests.

According to Rashit Hantemirov, of the Russian Academy of Science;

According to reconsructions most favorable conditions for tree growth

have been marked during 5000-1700 BC. At that time position of tree

line was far northward of recent one.

[Unfortunately, region of our research don’t include the whole area

where trees grew during the Holocene. We can maintain that before 1700

BC tree line was northward of our research area. We have only 3 dated

remnants of trees from Yuribey River sampled by our colleagues (70 km

to the north from recent polar tree line) that grew during 4200-4016

and 3330-2986 BC.]

This period is pointed out by low interannual variability of tree

growth and high trees abundance discontinued, however, by several

short (50-100 years) unfavorable periods, most significant of them

dated about 4060-3990 BC. Since about 2800 BC gradual worsening of

tree growth condition has begun. Significant shift of the polar tree

line to the south have been fixed between 1700 and 1600 BC. At the

same time interannual tree growth variability increased appreciably.

During last 3600 years most of reconstructed indices have been varying

not so very significant. Tree line has been shifting within 3-5 km

near recent one. Low abundance of trees has been fixed during

1410-1250 BC and 500-350 BC. Relatively high number of trees has been

noted during 750-1450 AD.

There are no evidences of moving polar timberline to the north during

last century.

http://www.ecowho.com/foia.php?file=0907975032.txt

Some of Mann’s own colleagues warned Mann about the unreliability of tree rings – this email from Tom Wigley, discussing how his son’s high school project falsified Mann’s research.

“Also, stationarity is the key. Let me tell you a story. A few years back, my son Eirik  did a tree ring science fair project using trees behind NCAR. He found that widths correlated with both temp and precip. However, temp and precip also correlate. There is  much other evidence that it is precip that is the driver, and that the temp/width correlation arises via the temp/precip correlation. Interestingly, the temp correlations are much more ephemeral, so the complexities conspire to make this linkage non stationary.”

http://www.ecowho.com/foia.php?file=0682.txt

On this occasion though, Keith Briffa decided to support his friend Mann with some helpful advice (from the same email as the Wigley quote) – Keith’s suggestion is that Mann could dismiss the relevance of previous warm periods being warmer than today, by spinning the suggestion that the current warm period is different, because it is anthropogenic;

“Mike there is often no benefit in bandying fine points of emphasis and implication- Hence , I think that what you have already drafted is fine. Do not start to dilute or confuse the issue with too much additional detail. The job , as you state , is to place on record the statement of disagreement with the “science(!)” and spin. To this end , it may also be worth stating in less couched terms that merely eyeballing the relative magnitudes of recent versus prior period(s) of large scale warmth, is in itself very limited as a basis for claiming the reality OR OTHERWISE of anthropogenic forcing of the recent warming ,  if this is done without reference to the uncertainty and causes of these differences. The points you make to Tom are of course very valid , but do not be tempted to guild the lily too much here – stick with your current content

http://www.ecowho.com/foia.php?file=0682.txt

Has any piece of scientific research ever been so thoroughly discredited? Tom Wigley’s son’s high school project falsified the hockey stick. The latest Sheep mountain study shows the hockey stick disappears, unless you use Mike’s trick of splicing in the thermometer record, to hide the divergence problem. The Russian scientists who collected the original tree ring samples, tried to warn Mann he was measuring the wrong metric. Yet somehow this nonsensical analysis became a central icon of the climate alarmist movement – and is still widely reproduced by the more scientifically illiterate alarmists.

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340 thoughts on “Mann's tree ring proxy train wreck

      • Hi Eugene. Summer is suppose to be here in NZ. However,crops are late due to cold nights. I don’t like to criticize other countries leaders,but I can’t help thinking the POTUS has lost his marbles. I would like to wish all readers here a merry Christmas and a happy new year. I read this site regularly,and get great pleasure reading the comments. Oh,do you know where NZ is? I would be willing to bet that the majority of Americans don’t even know who we are. Best wishes from NZ.

      • Hi Patrick,no reply on your post,so do it here. Yep,we are very small by world standards. We like to think we are big,but we are very small. We do have lots of sheep,and also lots of warmists who think we are doomed. Our climate is very cool by world standards,and would benefit with a few degrees of warming. Temperatures here are below normal,and maize and other crops are not living up to expectations,but may recover as the weather improves. All the best to you commenters over there,and have a good Xmas. Cheers from NZ,Best wishes,Billy NZ.

      • My post is more for others, it made me laugh when it was broadcast! Shbangabang! LOL Thanks! Lived in Wellington for about 9 years. All the best to you, family and friends over the Chrimbo hols.

    • Yes, in deed; instead of being at Penn State, he should be in the state pen. Crooked as a dog’s hind lag. By the way, isn’t New Zealand south of New England? Just guessing.

    • We Septics know where New Zealand is …….. we learned it from watching documentaries……

  1. Damned good read. We know Mann’s a fraud. Mark Steyn has his measure, and I hope he has his measure legally too. This article is some icing on the cake.

  2. Dr. Fraudpants as Mark Steyn has amusingly dubbed him, is becoming an increasingly isolated, Captain Queeg like figure. Things will not end well for Mr. Mann, from a professional point of view at least.

  3. I recall Jerry North, a climate modeler at Texas A&M University, relating that he and other modelers were “euphoric” when Mann’s hockey stick (HS) came out. It showed exactly the trend their climate models said should be happening: an unprecedented rise in air temperature since the early 20th century.
    Mann’s HS was a huge relief to them. It completely validated their climate models, and so was immediately and uncritically accepted throughout the community of modelers.
    I remember seeing a picture of Tom Stocker holding up a transparency of Mann’s hockey stick, looking at the camera with grim certainty equally mixed with I-told-you-so on his face.
    For me, that picture iconized the fixated attitude of the modeler community. The HS was everything for which they could possibly have hoped. They couldn’t give it up any more than a biologically disposed heroin addict could abandon the drug. The modelers have conquered climatology, climatology controls the AGW narrative, and so it all went.
    I searched but unfortunately didn’t find that picture again.

    • Alas, modelists will always suffer from not wanting to see real-world data.
      And modern climatologists will always suffer from not wanting to wait to accumulate real-world data.
      Put them together and what do you get…

        • So your response to my challenge is that there is a vast conspiracy involving thousands of hard-working scientists in collusion with the media and governmental administrators to perpetuate a lie to all of us?! Good luck with that. I suggest you start by reanalyzing the data, publish it in a peer-reviewed scientific paper and refute the conclusions of the National Academy of Sciences. I guarantee the media will pick it up and you will be famous!

    • Dr Mann is a reasonable, but by no means outstanding scientist, who unfortunately has been instrumental in over promoting the value of a branch of paleo proxy reconstructions-tree rings.
      Other proxies do not always agree with Dr Mann. It entirely depends on which cherry tree you want to pick from and whether you then turn the cherries upside down or not.
      Here is a graphic I created showing the advance and retreat of glaciers over the last 3000 years taken from thousands of references from Ladurie and Pfister. On to it has been placed the hockey stick which manages to sail on serenely at virtually the same temperature, whilst all around it glaciers advance and retreat. As regards glacier lengths, they are a reasonable temperature proxy bearing in mind we can not capture the nuances when movement is limited.
      http://wattsupwiththat.files.wordpress.com/2013/08/clip_image010.jpg
      The link below goes to the borehole database held by the University of Michigan.
      http://www.earth.lsa.umich.edu/climate/core.html
      It illustrates rising temperatures since 1500. Due to sampling problems I think we are safe to say from 1700, but 1500 seems doubtful. CET shows this 300 year rise as well.
      What are we to make of this as Dr Mann shows declining temperatures for the last thousand years until the sudden rise in the last century when he swapped cherries for oranges.(instrumental records are far more variable than paleo proxy reconstructions)
      Well, if you would like to look at the borehole data shown in the link, which is a pretty good proxy for other novel paleo methods, it seems you could reconstruct whatever temperature scenario you wanted.
      tonyb

      • Borehole temperature reconstructions in different publications from the maintainer of the University of Michigan’s database, Shaopeng Huang, who is considered one of the top experts in this field. Looks like there is lots of room for interpretation but there is a MWP in the data unlike what is shown in the hockey stick.
        http://jonova.s3.amazonaws.com/graphs/boreholes/huang-pollack-97-2000-2008.gif
        Then, how much variation there is individual boreholes from Harris and Chapman 2005.
        http://www.seafriends.org.nz/issues/global/borehole_harris_chapman2005.jpg

      • tonyb
        Calling Mann a “reasonable…scientist” seems a stretch. Frauds and cheats usually get called…wait for it…frauds and cheats. Doubly so when they blatantly use their tax-payer funding to ruin other, legitimate “reasonable scientists” who disagree with them.
        Reasonable? No.

      • “Dr Mann is a reasonable, but by no means outstanding scientist, who unfortunately has been instrumental in over promoting the value of a branch of paleo proxy reconstructions-tree rings.”
        Yikes. Such a thing as being too polite. I get that you want to be collegial Tony, but come on! A reasonable man does not act like a lunatic…by definition. Also I must take issue with your somewhat passive construction…as in “(Mann’s) been instrumental in over promoting…”
        This is not something that somehow…as if by bad luck….happened to him. Mann’s chosen the low road, a route he seems determined to pursue all the way to the bottom.

      • Chip and poker guy
        I meant ‘reasonable’ in the sense of being a scientist that is better than poor but not as good as brilliant. Perhaps mediocre would be better?
        I didn’t mean reasonable as in the sense that he is all sweetness and light in all his dealings.
        Tonyb

      • Dr. Mann has never demonstrated the quality of “reasonableness” to me, in my only interaction with the man, he demonstrated the qualities of pettiness and narcissism; perhaps I encounter him on a bad day, but my impressions have been reported by many.

      • “Other proxies do not always agree with Dr Mann. It entirely depends on which cherry tree you want to pick from and whether you then turn the cherries upside down or not.”
        This is such a misrepresentation that either it’s written by someone intent on spreading misinformation, or it’s written by someone who really doesn’t have a clue, and shouldn’t be writing about things he has failed to investigate with even moderate diligence.

      • Tonyb
        I’m a retired CFO, so my opinion on the totality of Dr Mann’s scientific academic work is meaningless. However, I suspect with the passage of time, Mann’s having relied on selected tree rings as a temperature record (accurate to 0.1 Celsius degree) will literally be view as a willful fraud.
        In my mind, this explicit and continued malpractice is of such gravity as to render his prior performance meaningless. I think we’ll have to agree to disagree on this one.

    • Pat Frank:

      I recall Jerry North, a climate modeler at Texas A&M University, relating that he and other modelers were “euphoric” when Mann’s hockey stick (HS) came out. It showed exactly the trend their climate models said should be happening: an unprecedented rise in air temperature since the early 20th century.

      It should be noted that Gerald North was the head of the NAS panel that investigated the hockey stick and who made the quote about how they “just kind of winged it”.

  4. The big question is why on earth anyone would think that temperature, rather than moisture, was the major determinant of tree ring growth. Any farmer could have told him he was nuts.

    • Mann oh Mann!

      WUWT – March 19, 2008
      Bristlecone Pines: Treemometers or rain gauges ?
      …One of the graphs Steve McIntyre recently produced was this one:
      “Here’s the MBH98 PC1 (bristlecones) again marking 1934. Given that bristlecone ring width are allegedly responding positively to temperature, it is notable that the notoriously hot 1934 is a down spike.”……
      No wonder 1934 is a negative on Man’s graph above, it was hot and dry that year. It’s been said that even grasshoppers were starving during that drought.
      http://wattsupwiththat.com/2008/03/19/treemometers-or-rain-gauges/
      =============
      WUWT – September 28, 2009
      A look at treemometers and tree ring growth
      The point I’m making with all this is: If “the total growth response of a tree is the product of all environmental factors”, and forest modelers have to separate temperature and precipitation diameter increments, plus create different models for different forest regions, how can then one accurately divine temperature over millenia from width analysis of tree ring growth from trees in a single region?
      http://wattsupwiththat.com/2009/09/28/a-look-at-treemometers-and-tree-ring-growth/

    • Exactly! No one who has a clue about trees ever thought there was a relationship between mean annual temperature and tree rings.

    • The greenist summers are the wettest summers around here but I’m not a farmer or a climate scientist.

    • @ arthur4563: December 6, 2014 at 7:55 pm
      The big question is why on earth anyone would think that temperature, rather than moisture, was the major determinant of tree ring growth. Any farmer could have told him he was nuts
      ——————
      (Just some trivial information that might interest WUWT viewers.)
      True, ….. but, ….. in actuality the major determinant of tree ring growth is light intensity ….. because light intensity determines the rate of photosynthesis ……. and the rate of photosynthesis determines the amount of sugars that are produced for use in tree ring growth.
      Except the early Spring growth, …. those sugars were produced the previous growing season and were stored in the roots. Think of …… Springtime Maple Syrup production.
      To wit:
      The main factors affecting rate of photosynthesis are light intensity, carbon dioxide concentration and temperature.
      In that order of importance, ……. but don’t panic, …… moisture is more important than temperature. But it is the soil moisture …. or …. amount of moisture in the soil.
      And don’t be forgettin that the growth rings get a “jump” start on their growth in early Spring when there is normally adequate soil moisture available (unless it was a cold dry winter).
      And I really don’t know of any means or methods one could use for determining per se proxy data for soil moisture content of bygone years, be it for one (1) year or one hundred (100) years.
      Reference: http://www.rsc.org/learn-chemistry/content/filerepository/CMP/00/001/068/Rate%20of%20photosynthesis%20limiting%20factors.pdf
      Cheers

      • Trees grow well if they get light, there’s moisture in soil, and the temperature is within certain limits. Both dry sunny and cloudy cold summers may be detrimental to tree growth. The treeline – location of northernmost trees – movement, OTOH, depends on warm summers because seeds won’t develop nor saplings grow in less-than-optimal weather.

  5. I’m all for Anthropogenic Global Warming, let’s make this a better warmer world.. All I see are people shivering and grey skies. rain and sleet, it’s basically miserable, sometimes snow and ice. Winter sucks and it will suck a thousand years from now, that’s my scientific opinion.

    • I’d imagine winter’s a lot of fun if you’re rich.
      If you don’t have to get up before the crack of noon.
      Don’t have to slop your way through the traffic to get to work.
      You snowmobile into town to have brunch at the local tavern.
      You spend an afternoon cross country skiing and have a warm cozy chalet to return to at night.
      You can drive your 4 wheel SUV to the airport and fly your private jet to spend a few weeks at your West Palm Beach winter home.
      “It’s good to be da king”
      Mel Brooks

    • And a very reasonable, but depressing opinion it is. Cold, gray….winter. My local sunset is currently 432pm…in 4 days it is 431pm….YES!!!

    • Because his iconic graph galvanized the world, including me at the time. I distinctly recall thinking, wow, this must be the real deal. It was all a lie.

      • If only Mann’s proxy carried on forward in time. Here’s big Mc

        Steve McIntyre
        The new results of Salzer et al 2014 (though not candid on the topic) fully demonstrate this point in respect to Sheep Mountain. In the warm 1990s and 2000s, the proxy not only doesn’t respond linearly to higher temperatures, it actually goes the wrong way. This will result in very negative RE values for MBH-style reconstructions from its AD1000 and AD1400 networks when brought up to date, further demonstrating these networks have no real “skill” out of sample.
        http://climateaudit.org/2014/12/04/sheep-mountain-update/

        Why did the mathematician and physicist, Michael Mann, decide he was better at reading tree rings? The above is the end result. Mann’s proxy – the HOT year of 1934 is a down spike. Sad.

      • Matt Ridley also says he was fooled:

        I can remember when I first paid attention to the “hockey stick” graph at a conference in Cambridge. The temperature line trundled along with little change for centuries, then shot through the roof in the 20th century, like the blade of an ice-hockey stick. I had become somewhat of a sceptic about the science of climate change, but here was emphatic proof that the world was much warmer today; and warming much faster than at any time in a thousand years. I resolved to shed my doubts. I assumed that since it had been published in Nature—the Canterbury Cathedral of scientific literature—it was true.
        I was not the only one who was impressed. The graph appeared six times in the Intergovernmental Panel on Climate Change (IPCC)’s third report in 2001. It was on display as a backdrop at the press conference to launch that report. James Lovelock pinned it to his wall. Al Gore used it in his film (though describing it as something else and with the Y axis upside down). Its author shot to scientific stardom. “It is hard to overestimate how influential this study has been,” said the BBC. The hockey stick is to global warming what St Paul was to Christianity.

        http://www.prospectmagazine.co.uk/magazine/the-case-against-the-hockey-stick

      • Because his iconic graph galvanized the world
        —————-
        The only “fake” that has been pictured more often than Michael Mann’s “Puckwhapper” is most probably the ones of the “Wrongheaded Dinosaur” …… (Brontosaurus).

    • Sparks:
      “Why is Mann getting so much attention for being wrong?”
      Because people still believe the documents he has cranked out over the years claiming that his work proves CO2 is the major cause of temperature change, and that mankind’s burning of ‘fossil fuels’ is largely responsible for those changes – in CO2 and temperature. What he has tried to show (using highly irregular methods) is that trees contain a temperature record in their growth patterns.
      As his 1998 work has been shown to be defective and has not yet been withdrawn, even though it can be and has been demonstrated that he knew at the time his results were not representative of the facts available (which alone is ‘good cause’ to withdraw) the paper is still cited as ‘evidence’ confirming the AGW hypothesis.
      Withdrawal of the ‘hockey stick papers’ would drive a wooden stake through the heart of the climate alarm blood-sucking vampire. Before that happens, the ‘Team’ has to find an alternative that is more believable and of approximately the same shape. In the absence of net warming for the past 18 years, there is no recent work that can produce such a temperature curve so they are ^creek -paddle.
      They tried to move the argument to ‘the heat contained in the system’, but that creates other problems the movement is ill prepared to solve. The error bar on the ocean heat content number is larger than the signal, for a start. The ‘imbalance’ is very much smaller than the error bars on the ground and satellites, and there is a viable alternative explanation that is related to solar CR, CFC’s (and their analogues) and ozone.
      See http://www.science.uwaterloo.ca/~qblu/qblu_website/Welcome.html if you have not encountered this work before. The Team has slipped a couple of (pretty bad) rebuttals into the mix but is staying away from making a lot of public noise about this guy’s ideas because it has a 0.96-0.97 correlation coefficient (1970-2012) with temperature. In other words, it ‘explains the rise and the pause’ – no CO2 required. The conversation in the articles continues, 2009-2014.
      In order for a workable ‘counter argument’ (that the data did not support that such a mechanism exists or could work) Muller et all 2010 had to go to Mannian lengths, using similar data from a satellite that does not cover the areas of the globe where the effect takes place (!) which prompted an interesting exchange, to say the least.

    • Because the National Academy of Sciences (2006) and many other analyses support his conclusions.
      “The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century
      warmth in the Northern Hemisphere was unprecedented during at least the last 1,000
      years. This conclusion has subsequently been supported by an array of evidence that
      includes both additional large-scale surface temperature reconstructions and pronounced
      changes in a variety of local proxy indicators, such as melting on ice caps and
      the retreat of glaciers around the world, which in many cases appear to be unprecedented
      during at least the last 2,000 years.”
      Surface Temperature Reconstructions for the Last 2,000 Years Committee on Surface Temperature Reconstructions for the Last 2,000 Years, National Research Council.
      This free PDF was downloaded from:
      http://www.nap.edu/catalog/11676.html

      • Everything you state has been falsified. Appeal to consensus as well as politically motivated leaders of various Science Academies does not mean that the CAGW meme is real. As I stated it has been falsified so many times that your stance should be an embarrassment to you — what is your favorite flavor of Kool-Aid.

      • 2006?! You’re kidding, right? Why are you citing a report from 2006 to support your claim when there are many studies since then?

      • “Melting on ice caps”. There are exactly two ice caps. Exactly one has melted somewhat from a given start point. That is exactly half of the ice caps. The other one has grown to record levels from the same given start point. None of what you have quoted is, “unprecedented”.

  6. I suspect there are a lot of honest climate/atmospheric physics professors out there who would refuse to read a paper with Mann as a co-author. His lies may have initially worked, as few would have thought such a big Lie would have been possible, but they are not stupid. The Mann climate science FAIL is coming.

      • No they are nasty little selles. They used the mann hockey stick to up their funding and then quietly disown him when the merde hits the fan. Really nice people the Climologues.

    • Although best known to the general public, like me, for his hockey stick paper he has written or co-authored more than 160 papers and his standing with students at his university is apparently amongst the highest. He is clearly not just a one trick pony – has anyone done a critical review of his overall contribution to climate science ? He must be approaching that stage in his professional academic career, common for distinguished professors , when students and colleagues mount a symposium in his honour , recalling achievements and presenting like contributions of their own .

      • Mann’s legacy will of statistical gamesmanship, a failure to embrace falsification, failure of replicable results, and massive egotistical outbursts, petulance, censorship on Twitter and RealClimate and his oppressive lawsuits will insure his reputation as a shoulder-less midget.

  7. There is a telling parallel to Church & White’s splicing of linear sea-level tide gauge data to (also linear) satellite data but adjusted to a different slope. The satellites don’t have the resolution accuracy of the tide gauges, yet they are gleefully “joined” to become “semi-empirical” – just what we always wanted!!!

  8. since tree rings have to be calibrated with more recent thermometer records I wonder how they manage to diverge … if you are calibrating with the last 100 years thermometer data then wouldn’t the last 100 years of trees rings almost exactly match the thermometer record ? isn’t that what it means to calibrate … year x temperature = y then year x’s tree ring width = y temperature … my bet is that they stopped calibrating at some point because it would cause the older tree ring data to have much higher temperatures … and that would kill the AGW myth …

    • The “divergence problem” appeared in the 1950’s or 60’s depending on which specific proxy. Basically before that time, tree rings seemed to track the instrumental record. Since the instrumental record only began about 1880, this means that for nearly half the instrumental, tree rings do NOT track temperature, calling into question their validity prior to 1880. If they can’t get 1950 to 2010 even close, there’s no reason to trust them from 1000AD forward.
      Mann’s “nature trick” was to hide this divergence from the instrumental record by replacing the tree ring data post 1950 or so with the instrumental record itself. That way nobody noticed (at first) that the tree rings “declined” while the instruments went up, falsifying the use of tree rings as proxies for temperature. This became known as the “trick” to “hide the decline”. Without it the 1000 year temperature reconstructions by Mann, Birffa, Jones, etc would been seen as completely useless from day 1.

      • “… before that time, tree rings seemed to track the instrumental record …”
        ========================================================
        Please correct me, but I thought they actually selected the tree-ring proxies which tracked the temperature records (at least as far as ~1950) and threw out the rest thus guaranteeing a hockey stick blade shape at the end of what was, in effect, (almost) a linear trend line handle — the average of widely divergent proxies before ~ 1880.

      • Christopher Hanley December 6, 2014 at 11:11 pm
        >>>>>>>>>>>>>>>
        Well that too. It is actually a rather complicated trail, and trying to summarize in a paragraph or two results in many chapters being left out. Essentially the Hockey Stick is one story line, and Hide the Decline a different (but over lapping) story line. If you want the full details, Climate Audit goes into excruciating detail, and there are a number of good articles archived on this site as well.

    • JeffC
      since tree rings have to be calibrated with more recent thermometer records I wonder how they manage to diverge … if you are calibrating with the last 100 years thermometer data then wouldn’t the last 100 years of trees rings almost exactly match the thermometer record ? isn’t that what it means to calibrate … year x temperature = y then year x’s tree ring width = y temperature … my bet is that they stopped calibrating at some point because it would cause the older tree ring data to have much higher temperatures …

      Could be. But. Consider the following as well.
      Mann’s Theory of Tree Ring Temperature Proxies requires that tree ring width (amount of growth each year) be proportional to local temperature – which is turn is assumed equal to global temperatures as measured by thermometers and inferred by other proxies, right?
      Now, Mann either corrects for local precipitation, or assumes all precipitation in a single area is always the same for every tree in that area. (Or he manually selects out trees which do NOT follow the assumed temperature-tree-ring-width profile so precipitation variations are excluded for every tree that Mann reports data about. The rest? Not revealed. Did he measure 12 trees in Yamal – and only use one? 60? 120? )
      But … Tree ring width is ALSO proportional to the amount of CO2 available to that tree in every summer that the tree experiences.
      Thus, more CO2 over time (1860 – 1998) -> Faster growth each summer between 1860 and 1998 -> Wider tree rings as the tree gets older -> Conclusion: Higher Temperature each summer between 1860 and 1998, with the fastest growth in the ytears AFTER 1960!

    • A simple method of linear calibration is to cross plot measured temperature versus tree ring. The slope of that line is the calibration factor. You could also remove the later diverging years from the data set and recompute the slope of the line for a better fit. If you then spliced the later measured temps onto your calibrated proxy data the fit would look even better. But that would be cheating.

  9. The whole aim of Mann’s shenanigans is to keep the populace alarmed — and hence clamorous to be led to safety through endless funding — by menacing it with an endless series of hobgoblins, all of them imaginary and manufactured by sleight of hand, pen and schticks..

  10. “To this end , it may also be worth stating in less couched terms that merely eyeballing the relative magnitudes of recent versus prior period(s) of large scale warmth, is in itself very limited as a basis for claiming the reality OR OTHERWISE of anthropogenic forcing of the recent warming , if this is done without reference to the uncertainty and causes of these differences.”
    What a wonderfully scientific sentence, ummm, What? I would retire from public life before ever uttering such a sense-free four-line balderdash…

  11. I wrote this a few years ago and every once in a while I re-post it.
    THE HOCKEY STICK
    There was a crooked Mann
    Who played a crooked trick
    And had a crooked plan
    To make a crooked stick
    By using crooked math
    That favored crooked lines
    Lysenko’s crooked path
    Led thru the crooked pines
    And all his crooked friends
    Applaud what crooked seems
    But all that crooked ends
    Derives from crooked means
    Eugene WR Gallun

    • Probably a lot. Mann also got half a million dollars from Obama’s stimulus fund, for no specific reason, other than a general suggestion he use the money to perform more research into climate change.
      http://online.wsj.com/articles/SB10001424052748703657604575005412584751830
      But I don’t think the evidence supports the idea that they are just in it for the money. I think its more likely, that they are so sure they are right about global warming, they discard or disregard any evidence which contradicts their idea of what is true. Their mission to save the world supersedes their duty as scientists to report all the facts, including adverse evidence.

      • Agreed, Eric. They CARE about the planet. Not like those fossil fuel funded deniers. We should listen to them, and accede to their demands, because their MOTIVES are un-reproachable. If they have to lie a little, well, it’s all for a good cause.

    • Well, Hansen became a $multimillionaire as a result of his public offerings so I guess Mann did, and is still doing, quite well.

  12. We must never forget the harm that this person has done, the reputations of fine scientists needlessly attacked, the science put to one side so that this guy can have his ego stroked by his fellow travellers in the alarmist church.
    He should be hung out to dry as a prime example of despicable behaviour, and stripped of his ill gotten gains.
    He had the opportunity many times to admit his culpability, or mask that with an acknowledgement he made an “honest mistake”. He chooses to continue to deny his work is substandard and promote the big lie that he and his pal reviewers actively promoted and defended.
    This would be “Emperor of Climate ” is nakedly exposed as nothing more than a rent seeking opportunist, and in reality Climate Parasite No 1 in a long line waiting to be exposed!.

    • “He had the opportunity many times to admit his culpability, or mask that with an acknowledgement he made an “honest mistake”. He chooses to continue to deny his work is substandard and promote the big lie that he and his pal reviewers actively promoted and defended. ”
      /////////////////////
      Now a lot of people dislike accussing the warmists of fr**d, and instead suggest that they exhibit incompetence, and all is perhaps an honest but negligent mistake. May be it was originally, but as Ken points out, the plain fact is that there have been many opportunities to correct the record, to withdraw the paper and to own up/fess up to the mistaken science. Why is this not being done? Surely, one could expect honesty in science to do this?
      The Hockey Stick is no longer the poster child of the IPCC because they know that it is unsound and discredited work, but this is kept quiet from the media and the public.
      As can be seen from the similar article on Bishophill, the problem is that honest scientist are not sticking their heads above the pulpit and calling out this work for what it is; nemely fundamentally flawed. This should be shouted from the hill tops. Climate science cannot move on until this is acknowledged.
      The problem is that the true history of climate in the NH needs to be restored, ie., that there is in fact no lengthy uniform handle, and that it consists of ups and downs with the MWP being warmer than today, and that all we are seeing today is a recovery from the LIA, which recovery in the late 20th century may or may not be added to by CO2 emisssions.
      Scientists also need to be honest and admit that we do not know what the past history is on a global basis simply because there is little reliable data covering the SH. We can only deal with the NH, and we know that there were a number of warmer periods in the NH, namely the Minoan, Roman and MWP. The AGW/GHE theory has to explain the pattern of the NH waring and cooling.

    • In a long line waiting to be exposed.
      I’m glad you mentioned that. That line must be exposed all the way to the top and have them held accountable for their lies. The ramifications must be so severe it would never happen again.

  13. this comment has very little to do with my post at Climate Audit. Nor is “Mike’s Nature trick” relevant to the topic discussed at CA. Nor has Mike’s Nature trick been correctly described in the above article.

    • Steve, I apologise if I have misunderstood what you wrote – that wasn’t my intention.
      My comment about the “thermometer spliced hockey stick” was a reference to this post;
      http://climateaudit.org/2009/11/20/mike’s-nature-trick/
      “When smoothing these time series, the Team had a problem: actual reconstructions “diverge” from the instrumental series in the last part of 20th century. For instance, in the original hockey stick (ending 1980) the last 30-40 years of data points slightly downwards. In order to smooth those time series one needs to “pad” the series beyond the end time, and no matter what method one uses, this leads to a smoothed graph pointing downwards in the end whereas the smoothed instrumental series is pointing upwards — a divergence. So Mann’s solution was to use the instrumental record for padding, which changes the smoothed series to point upwards as clearly seen in UC’s figure (violet original, green without “Mike’s Nature trick”).”
      Perhaps “thermometer spliced hockey stick” was insufficiently concise, but I wasn’t trying to describe the nature trick in detail – that has been covered elsewhere.
      And the understanding I had from your post about the nature trick, was that the instrumental record was used to adjust the slope of the hockey stick reconstruction – and that your post about Sheep mountain indicates that the divergence problem shows no sign of letting up, with at least some out of sample proxies.

      • Saw this coming. I’d suggest withdrawing the post and reworking it until it is an honest interpretation of Steve’s work. That work, btw, stands on its own merit. This just looks bad – for you and for Anthony’s blog.

      • Don’t take Steve McIntyre’s comment too hard, Eric. Steve noted previously that one has to be “microscopically correct” when dealing with the Team’s oracular science, otherwise they play gotcha over some small thing to discredit one’s entire analysis. Steve’s quite right about this. We’ve all noted it
        So, Steve has to dissociate himself from a post that doesn’t get his work exactly right. Doing so prevents anyone from using such a post as a straw man, as a means of discrediting Steve.
        The hockey stick in MBH98/99 depended on Mann’s use of short-centering in the PCA analysis to elevate the White Mountain strip-bark pine series into PC1. Strip bark pine series provided the entire HS. As Steve noted, without the strip-bark pine series plus the fake PCA method, the MBH98/99 network just produced trendless noise.
        Your post has the right overall judgment. Steve’s new post shows a huge new problem for the MBH corpus. The critical MBH98/99 White Mt. series ended in 1980. Sheep Mountain is part of the White Mountain range.
        Steve’s new post shows that tree ring width series from south-facing Sheep Mountain pines, which are out-of-sample with respect to MBH98/99, show a decline past 1980. That is, they show the divergence problem, now found in many places across the northern hemisphere.
        That result pretty much discredits the entire thermal signification of the White Mountain strip-bark series themselves, as used in MBH98/99, completely apart from the statistical mummery used to promote them. They are now known to not signify anything about air temperature, no matter how strong one’s wishful thinking otherwise.
        The Sheep Mountain north-facing pines don’t produce a very exciting correlation, either, by the way, with the canonical global air temperature record.

      • dp
        Steve McIntyre has done outstanding work in investigating the construction and faults with Mann’s ‘hockey stick’ and it is undoubtedly true that his work “stands on its own merit”. You are also right to say an intervention of the type provided by Steve McIntyre could have been expected but NOT for the reason you state.
        Steve McIntyre has come to see scientific exposure of Mann’s ‘hockey stick’ as his personal domain, and he always objects when others step into what he now considers to be his territory. This is not the first time he has done it on WUWT and it can be anticipated to not be the last.
        The entire post from Steve McIntyre says

        this comment has very little to do with my post at Climate Audit. Nor is “Mike’s Nature trick” relevant to the topic discussed at CA. Nor has Mike’s Nature trick been correctly described in the above article.

        That post is not criticism but is what is commonly called ‘knocking copy’. It consists of a series of unsubstantiated and unspecific complaints that – if true – cannot be answered because there are no stated faults to answer.
        “very little to do with [McIntyre’s] post at Climate Audit”?
        Perhaps “very little” but some and Eric Worrall quotes it verbatim in his article.
        “Nor is “Mike’s Nature trick” relevant to the topic discussed at CA.”?
        Really? In what way is it “not relevant” when Eric Worrall explains his cogent understanding of the relevance?
        “Nor has Mike’s Nature trick been correctly described in the above article.”
        Really? Steve McIntyre states no fault in the description in the article of “Mike’s Nature trick” so how is Eric Worrall supposed to respond to that?
        But Eric Worral did not take understandable umbrage at the post from Steve McIntyre: instead, he attempted to ‘smooth ruffled feathers’ by posting a gracious response which began saying

        Steve, I apologise if I have misunderstood what you wrote – that wasn’t my intention.
        My comment about the “thermometer spliced hockey stick” was a reference to this post;
        http://climateaudit.org/2009/11/20/mike’s-nature-trick/

        Then, in the tradition of cowardly thugs kicking a man when he is down, you join in by falsely asserting the article by Eric Worrall was not “an honest interpretation of Steve’s work”.
        Eric Worrall did no wrong but had the good grace to apologise for any misunderstanding he may have had of the writings of Steve McIntyre.
        dp, your false accusation of dishonesty by Eric Worrall was thrown from behind the coward’s shield of anonymity and is despicable. Many people around the world are watching and waiting for your grovelling apology and withdrawal.
        Richard

      • When referring to MBH 98, “thermometer spliced hockey stick” is completely wrong. That’s the problem. Mann achieved his HS by overweighting bristlecone time series by 391 times, thus overwhelming the effects of any of the other non-HS proxies.
        So yes, you need to amend your post consideranbly.

      • Jeff Alberts
        You wrongly assert

        When referring to MBH 98, “thermometer spliced hockey stick” is completely wrong. That’s the problem. Mann achieved his HS by overweighting bristlecone time series by 391 times, thus overwhelming the effects of any of the other non-HS proxies.
        So yes, you need to amend your post consideranbly.

        YOU ARE WRONG. There is no need to amend the article.
        The fact that MBH 98 was a “thermometer spliced hockey stick” was the first fault observed in MBH98, and the ‘climategate’ emails revealed that Mann was trying to mislead about this fact long before many (including Steve McIntyre) began to investigate MBH98. The matter has been much debated in the past including in a dedicated thread on WUWT.
        The splicing of dis-similar data sets was only one of many faults with MBH98. Your citation of another fault with MBH98 does not alter the fact that the first fault to be observed with MBH98 is that it was a “thermometer spliced hockey stick”.
        Richard

    • Steve,
      I think a more gracious response would have been in order. Common courtesy and all that. Perhaps a private email to Eric so he could correct this post if needed? After all, he was complementing your work.

    • Steve, why then don’t you bother to explain Mike’s Nature trick, or offer a link to a better explanation!
      This question is crucial to the larger mainstream debate and you only obscure the issue further, with comments, that at least for my part, appear cryptic.
      My understanding is that the proxy construction (As composed by Mann) declines and therefore it was difficult to splice a climbing instrumental record onto it. The lack of a match between the proxy and the instrumental temperature record, for a layman at least, would logically falsify either or both!
      The claims made by Mann’s graph are far more mundane and far reaching in the public domain than the esoteric subtleties you appear to be at pains to point out.

    • I was also puzzled that Anthony did not get what “mike’s nature trick” was all about, but now I understand that it was someone called Eric Worrall who wrote this post. As others have said, this post should be amended or withdrawn.

      • But “Mike’s Nature Trick” is not what happened with the original HS, which is what SM’s post was about.

      • pax
        There is no Law which decrees Steve McIntyre has right of veto over what is said or who can discuss MBH98.
        And there is absolutely no need – none, zilch, nada – to amend or withdraw the article.
        Your suggestion of such a need is either ‘false flag trolling’ or is as mistaken as the comments by Jeff Alberts, so I refer you to my above refutation of his assertions in this thread: this link jumps to that refutation.
        Richard

    • Steve: That was immediately obvious from having previously read multiple threads on Climate Audit. But not everyone is able to keep up with the facts in this complex area, especially when “Mike’s Nature trick” continues to be incorrectly (and frequently) cited elsewhere. Thanks for putting in a word to keep the record accurate. It’s important.

      • mpainter
        You say

        I think Steve McIntyre meant exactly what said.

        Perhaps. But if you think that then perhaps you can help the discussion by explaining what Steve McIntyre meant.
        I refer you to my above post which is here and lists the imponderables of what Steve McIntyre meant.
        Richard

  14. I wonder….
    What is the shape of a graph (time on the x-axis, total dollars spent on the y-axis) of the total taxpayer dollars spent by Mann and his organizations to hide his data, methods, and computer programs from the people who were forced to finance his ‘studies’?
    THIS might be the REAL ‘Hockey-Stick’!
    By the way, am I correct in my basic understanding that publicly-funded scientific studies are supposed to be available to the public? …. that the people who provided the money get to see what their money was spent to create?

  15. wait a minute…
    There should have been increasing width of tree rings as CO2 increases…unless the climate is cooling even worst than I can imagine, or there was less rain, or essential nutrients were used up, or older trees grow slower, or…..never mind.
    Apparently the planet threatening increase in atmospheric CO2 concentrations does not even register as plant food.
    Oh well.

  16. The Mann hockey stick ‘problem’ is more than incorrect proxy data.
    The Mann hockey stick problem has four components: 1) cherry picking proxy data to create the hockey stick, 2) incorrect non-standard data analysis techniques which appears to be specifically done to create a hockey stick temperature graph (this interpretation of what transpired is supported by ‘scientist’ to ‘scientist’ climategate email communication (hide the decline emails), 3) efforts to withhold the incorrect data and analysis techniques from third party analysis to validate or invalidate the analysis, and 4) finally most importantly calling those who point out other proxy data sources unequivocally supports the assertion that planetary temperature cyclically warms and cools, ‘deniers’.
    Nor is the hockey stick ‘problem’ which is called ‘climategate’ limited to Mann’s data and analysis. There is a select group of ‘scientists’ who it appears obviously have and continue to manipulate data/analysis to push the extreme AGW paradigm. For example, there has been a steady change in recent temperature records for example where past temperature records are reduced and recent temperature records are raised to create a ‘hockey stick’, to hide the fact that planetary temperature is not significantly increasing. The scientific evidence does not support the IPCC predicted extreme AGW.
    http://www.uoguelph.ca/~rmckitri/research/McKitrick-hockeystick.pdf

    What is the ‘Hockey Stick’ Debate About?
    … At the political level the emerging debate is about whether the enormous international trust that has been placed in the IPCC was betrayed. The hockey stick story reveals that the IPCC allowed a deeply flawed study to dominate the Third Assessment Report, which suggests the possibility of bias in the Report-writing…
    …The result is in the bottom panel of Figure 6 (“Censored”). It shows what happens when Mann’s PC algorithm is applied to the NOAMER data after removing 20 bristlecone pine series. Without these hockey stick shapes to mine for, the Mann method generates a result just like that from a conventional PC algorithm, and shows the dominant pattern is not hockey stick-shaped at all. Without the bristlecone pines the overall MBH98 results would not have a hockey stick shape, instead it would have a pronounced peak in the 15th century.
    Of crucial importance here: the data for the bottom panel of Figure 6 is from a folder called CENSORED on Mann’s FTP site. He did this very experiment himself and discovered that the PCs lose their hockey stick shape when the Graybill-Idso series are removed. In so doing he discovered that the hockey stick is not a global pattern, it is driven by a flawed group of US proxies that experts do not consider valid as climate indicators. But he did not disclose this fatal weakness of his results, and it only came to light because of Stephen McIntyre’s laborious efforts
    Another extension to our analysis concerned the claims of statistical significance in Mann’s papers. We found that meaningless red noise could yield hockey stick-like proxy PCs. This allowed us to generate a “Monte Carlo” benchmark for statistical significance. The idea is that if you fit a model using random numbers you can see how well they do at “explaining” the data. Then the “real world” data, if they are actually informative about the climate, have to outperform the random numbers. We calculated significance benchmarks for the hockey stick algorithm and showed that the hockey stick did not achieve statistical significance, at least in the pre-1450 segment where all the controversy is. In other words, MBH98 and MBH99 present results that are no more informative about the millennial climate history than random numbers. …

    http://assassinationscience.com/climategate/cg.pdf

    Why Climategate is so distressing to scientists
    by John P. Costella | December 10, 2009

    http://www.climatechangefacts.info/ClimateChangeDocuments/LandseaResignationLetterFromIPCC.htm

  17. There are a whole lot of environmental variables that could influence tree growth/ring width. Precipitation, soil nutrients, aspect, to name some; as well as interactions between them. Is there anywhere published that temperature was shown to be the primary driver compared with the other possibilities.

  18. Who are you to question Mann’s authority? He is a Nobel Prize winner, after all, is he not?
    https://johnosullivan.files.wordpress.com/2012/10/manns-certificate-prover-he-was-an-ipcc-helper.jpg
    Just like Ivan Gorchev. In The 14-Carat Roadster, I mean.

    Ivan Gorchev, sailor on the freight ship ‘Rangoon’, was not yet twenty-one when he won the Nobel Prize in physics. To win a scientific award at such a romantically young age is unprecedented, though some people might consider the means by which it was achieved a flaw. For Ivan Gorchev won the Nobel Prize in physics in a card game, called macao, from a Professor Bertinus, on whom the honour had been bestowed in Stockholm by the King of Sweden a few days earlier. But those who are always finding fault don’t like to face facts, and the fact of the matter is that Ivan Gorchev did win the Nobel Prize at the age of twenty-one.

  19. The statement ‘discussing how his son’s high school project falsified Mann’s research’ is sloppy.
    It implies that the son’s research was somehow used to falsify or alter Mann’s results.
    It would be better to say that the son’s project showed that Mann’s data was flawed, or based on a false premise.

    • “It would be better to say that the son’s project showed that Mann’s data was flawed”
      It doesn’t even show that. The son cored some trees at NCAR, in Boulder Colo. That’s not Mann’s data. There’s a reason why Mann’s data comes from places like Yamal and Sheep Mtn, rather than somewhere more convenient like NCAR. It’s what they do to try to separate temperature effects. Of course in a place like Boulder, they won’t be separated.
      The email discussion is quite interesting. Omitted here is the final para:
      ” I have not seen any papers in the literature demonstrating this — but, as you point out Mike, it is a crucial issue.”
      It’s a serious discussion about stationarity assumptions.

      • Nick: I made my comment in order to highlight the use of poor English rather than enter a discussion as to what was or was not shown.
        I notice the use of the term ‘stationarity’. Presumably this refers to the location or position of the trees. It could be that ‘stationarity’ appears in the American Webster’s dictionary, but it’s not in my Concise Oxford Dictionary here in the UK.
        Why use words like this when the English language language contains other which immediately convey the correct meaning? I have an American general science textbook from the mid-1970s which is in excellent standard English, easily understood internationally.
        Much as I admire a lot about America and its culture, the desire to invent unnecessary new words to replace existing ones has me puzzled, and at times irritated because the meaning is not clear!

      • Carbon500:
        “I notice the use of the term ‘stationarity’. Presumably this refers to the location or position of the trees.”
        No, it refers to the stability of random variable distributions over time, the random variables being the various proxy measurements of tree ring dimensions and such. Distributions are said to be strongly stationary if the distribution mean and variance do not vary over time. Or weakly stationary if the covariance does not vary over time.
        The advantage in assuming stationarity is that such systems can be characterized by simple linear, time-invariant operators.
        http://en.wikipedia.org/wiki/LTI_system_theory
        The disadvantage is that “interesting” systems (e.g. climate) are usually not stationary in the strong sense.
        So compromises are made, assuming weakly stationary processes, synthesizing piece-wise stationarity. Also ‘cyclic’ stationarity is useful for analysis and modeling.
        http://en.wikipedia.org/wiki/Stationary_process
        http://en.wikipedia.org/wiki/Cyclostationary_process

      • Carbon, most real scientists and engineers still use standard English as they have no need of the obfuscation and misdirection that others create new words to accomplish. (Written as an engineer who is in no way, shape, manner or form a proper user of the English language… according to every English teacher who ever attempted to teach me.)

    • Carbon 500 says; “… in order to highlight the use of poor English…”
      I bet you meant “… the poor use of English…”

      • Johanus
        “No, it refers to the stability of random variable distributions over time, the random variables being the various proxy measurements of tree ring dimensions and such. Distributions are said to be strongly stationary if the distribution mean and variance do not vary over time. Or weakly stationary if the covariance does not vary over time.
        The advantage in assuming stationarity is that such systems can be characterized by simple linear, time-invariant operators.”
        But does not one first have to prove, or at least assume, that the “random” variables are independent? Salzer et al collected to cores from each of four very close growing trees at four different elevations. It is obvious that, at best, they had only sixteen independent tree width readings. Although they have thirty-two cores, there are only eight North facing and eight South facing trees. As the authors themselves very honestly wrote “We recognize this is a small number of trees that is approaching the lower limit of sample replication that should be averaged in mean time series and processed in dendroclimatic analyses. While the time series statistics suggest a strong common signal (table 1), for future research and subsequent analyses we recommend sampling more trees.”
        Because of thIs lack of data and in order to obtain their 95% confidence limits the authors resorted to “bootstrapping”, a process that is only valid if it is first proved that each reading are independent and that there is no serial correlation.
        I believe that the authors should have placed more emphasis on the word “suggest”, particularly since for the last fifteen years North facing and the South facing showed significantly different results.

      • Solomon Green:
        “But does not one first have to prove, or at least assume, that the “random” variables are independent? “
        Not really. The only thing that has to be “proved” is the skill of the model. If it explains or predicts everything as it should, then its allegiance to ideal technical assumptions is moot. Because these technical ideals (linearity etc) don’t exist in the real word in a pure form anyway.
        Anyway, the measurements taken from these four trees, closely collocated, will probably be imprinted with common meteorological and climatological patterns on a synoptic scale and larger. Also we’re looking for a common signal from the CO2 density. So there’s a lot of built-in dependencies.
        The skill of model is the bottom line. Period. Doesn’t really matter how it was created, as long as it reliably predicts or explains itsad-hoc model of the world.

      • I’d like to thank everyone who’s responded to my comments about the use of English, I’ve enjoyed reading your varied views and input very much. Clearly my well-thumbed mid-1970s copy of ‘Mathematics for Scientific and Technical Students’ by H.G. Davies and G.A. Hicks is not enough to ‘cover all the bases’ as the saying goes!

  20. I disagree with the quibbles about this post. The post is an opinion piece that tries to tell the common man about this important new development in the “hockey stick” story.
    The “hockey stick” graph did galvanize political action across the industrialized world and led to much higher energy costs, less industrial productivity, increased poverty, and the deaths of many people in the winter due to these factors. This “hockey sticky” con game needs to be talked about at the level that the common person can understand and then relate to friends and relatives.
    I realize that Steve McIntyre has a much more technical (and technically correct) take on this issue, but he loses me sometimes and I have been guilty of teaching statistics before. So, let us remember that the appropriate level at which to teach or impart information depends on many factors (like age, ability, preparation, and so on).
    It is important to remember that opinion pieces play an important role on this web site and that many readers are not professional data manipulators. (I tried to flip my checking account data upside down but my bank was not amused for some reason)
    For the above reasons (and more) I say good job Eric Worrall.

    • What markstoval said.
      I have nothing but admiration for Mr. McIntyre’s persistence and analytic ability, and the world owes him a lot. But his writing is frustrating, and I almost never have the time to run down all the acronyms, allusions, and terms of art necessary to comprehend his posts fully. Mr. Worrall is to be thanked for attempting to convey Mr. McIntyre’s work to a wider audience, and we would all be much better informed if Mr. McIntyre could collaborate with someone like Mr. Worrall to translate all of his posts into English.

      • +1 to that. I hope Eric isn’t put off contributing. I am an expert in my particular field of engineering, and I often try to help others for free on forums. Today, I posted a lengthy, helpful piece, which took up a part of my restful Sunday. The piece received a snide comment from a peer who isn’t as knowledgeable as myself (from what he wrote). It just makes you want to give up helping, because you think, what’s the point? I often get to the point where I will never contribute to any forum, because people can be such $hits.

      • Steve McIntyre actually is better than average in his scientific writing, with very few glitches. There are quite a few others who do need the collaboration you call for, but it wouldn’t hurt for Steve to have someone give his posts a quick looking-over for clarity, as well.

  21. Malfeasance by proxy?
    I really couldn’t care less who did what and how and by how many. When, where it [man made warming from CO2] became a problem is, when Governments started to use my money [taxes] to prove a myth [CAGW]. Penn State et al, UEA[CRU], the Met Office – if you swallow up public funds then you are on the payroll – Goddammit: should we not at least expect some, even a glimmer of objectivity?
    The alarmist cabal and particularly certain individuals, are so cocksure of themselves, so right – always and will brook with no arguments. With straight faces and all sense of humour bypassed, shouting, “the science is settled” they piously exclaim but how is any of this ‘science’ – this is Art and the black arts at that.
    Most good scientists, even some of his crony conspirators now deem him a leg iron, a pariah if you like.
    But because, in political circles were it not for some very red faces and attempts to save face and with a president who does not listen to anybody – ever. With a corporate blob and noted investment banks, the green megalomaniacs are baying for new emissions targets, the man made warming myth is [has to be] perpetuated. Thus, the media and Washington [Westminster/EU/UN in cahoots too] bubble close ranks and certain individuals remain bullet proof. A cynic may suggest, “man, it’s a good job he ain’t a representative of the Tea Party”.
    And a man would, should be presently seeking new employers, if……… anybody would have him.

  22. Here is something from the paper.

    Abstract – 9 October 2014
    Changing climate response in near-treeline bristlecone pine with elevation and aspect
    Abstract
    ….At the highest sites, trees on South-facing slopes grow faster than trees on North-facing slopes. High growth rates in the treeline South-facing trees have declined since the mid-1990s. This suggests the possibility that the climate-response of the highest South-facing trees may have changed and that temperature may no longer be the main limiting factor for growth on the South aspect. These results indicate that increasing warmth may lead to a divergence between tree growth and temperature at previously temperature-limited sites.
    …..4. Conclusions
    Dendroclimatology relies on networks of sites that represent approximations of the shared temporal variability found in collections of tree-ring samples from a particular location (Fritts 1976, Hughes 2011). Sites are areas thought to be similar with respect to the factors determining the climate control of tree-ring variability. The site principle relies on a common signal among all of the samples contributing to the site chronology due to their like responses to the same growth-limiting factor(s). We have shown that approximately 60–80 m of vertical elevation can be sufficient to create a change in the climate response of bristlecone pine. Trees below this elevation are not as effective temperature recorders as trees at treeline. Such fine-scale sensitivity, if present at other treeline sites around the world, would have important implications for chronology development and inferences of past climate variability. Treeline site chronologies should be constructed with this vertical heterogeneity in mind. Samples from upper treeline and from trees below treeline should not be mixed to avoid a ‘diluted’ or ‘mixed-signal’ site chronology, particularly at treeline sites that occur in relatively dry environments such as the White Mountains of California. Similarly, treeline samples from differing aspects should not be mixed to avoid problems and uncertainties related to potential ‘divergences’ and to ‘dilution’. Interpretations of existing bristlecone chronologies need to take this into account, particularly when these ring width chronologies are used in climate reconstructions. Furthermore, bristlecone pine dendroclimatological research would benefit from the pursuit of mechanistic studies of bristlecone radial growth and from directly measured temperature and moisture variability in high alpine environments. Such research would help to more accurately describe the species response to climate variability. Millennial-length bristlecone pine tree-ring chronologies are an extremely valuable paleoclimatic resource. New studies that emphasize the importance of precise individual tree location and the measured physiological response of these trees to quantified local values of temperature and moisture will be a step toward using these archives to their full potential.
    http://dx.doi.org/10.1088/1748-9326/9/11/114007

  23. Herbaceous plants such as crops and flowers are sensitive to temperature and other variables, but trees not nearly as much. Trees are used to dramatic and sudden temperature shifts and like most plants are photothermoperiodic. It’s obvious to those working in those areas whether or not they’ve had basic plant science. While several factors may affect tree growth(and tree rings), assuming temp’s are withing normal bounds that trees easily handle and mineral availability hasn’t suddenly changed(no reason for sudden changes), the primary limiting factor will be moisture. Mann should’ve known that and probably did.

    • Also, some tree families are very sensitive to moisture conditions and it’s availability and develop vascular disease such as anthracnose, especially those in the maple family(Acer). Verticillium wilt causes massive damage to the vascular tissue and that is apparent when tree rings are studied. The rings are hardly a proxy for temperature and limiting factors and disease are apparent upon close examination. When moisture sensitive disease or stress is dominant, other variables have important parts to play, such as a hot year that intensifies the condition. And when some trees are stressed or diseased, moisture uptake for respiration will be diminished.

  24. I think it`s fine Jimbo to get a constructive discussion of tree rings and temperature. Could it be a proposal to get a serious presentation of tree rings and temperatures from a scientist who know the difficulties with making proxies.

  25. This is turning out to be a real tree-ring circus. The star of the show is our favorite clown, Dr. Michael Mann. He sure makes me laugh.

  26. From WUWT sept 17. “…scientists are putting the growth acceleration down to rising temperatures and the extended growing season. Carbon dioxide (CO2) and nitrogen are other factors contributing to the faster growth.”

    • The Piltdown analogy deserves explication for the newcomers.
      In the late 19th, the science of “evolution” was hotly debated. It was assumed that if the science were correct, samples of ancient animals of “transitional form” would sooner or later be dug up. A sample was produced from a region called “Piltdown” that possessed jaws and fangs similar to an ape’s, but a large skull similar to a human’s. This sample was widely hailed as proof of evolution. Some critics argued the sample was fraudulent, “spliced together” (so to speak) from the pieces of two different specimens. Supporters, over time, argued variously that (1) the producers of the Piltdown sample were all honorable men, would never make mistakes of this sort, and certainly would not knowingly “splice” samples; (2) other researchers in other regions and with other species had ALSO found “transitional fossils”, therefore, since these replicated the Piltdown sample’s general role in the argument, and since these OTHER fossils were genuine and uncriticized, THEREFORE Piltdown fossils should also be regarded as genuine; (3) many of the critics were unscientific, even religiously biased against the whole concept of evolution, and therefore their critiques should be rejected without any consideration at all (4) EVEN IF the Piltdown samples were fraudulent, “evolution” was true.
      Eventually the Piltdown Man sample was revealed to conform to a pattern later summarily applied to Michael Mann’s work: “Method Wrong + Answer Correct = Bad Science.”
      Personally I would not be upset if the word wrong were considered synonymous with “fraudulent”.
      I also note that while “Evolution” as science is settled, the political consequences of assuming “something must be done” because of the “looming catastrophe” implied by that science resulted in the Nazi Holocaust –among other enormities– sprung from the minds of eugenicists, phrenologists and tribalists rallied under the banner of “science”.

      • When actual fossils of transitional apes were found, they proved to be the opposite of the fraud. Australopithecus, discovered in South Africa in 1924, had the brain capacity of a chimp but walked upright.

      • Did Australopithecus walk upright? Richmond and Strait (Nature 404:382–5 Jan., 2000) reported that Australopithecus was a knuckle walker, not bipedal. This calls into question whether Australopithecus was a transitional ape, or just an ape.
        SR

  27. And the results are not claire cut. Other studies (from Canada) show ftree growth decline with more warming.
    “Our results show an unexpected widespread tree growth decline in temperate and boreal forests due to warming induced stress but are also suggestive of additional stressors. Rising atmospheric CO2 levels during the past century resulted in consistent increases in water use efficiency, but this did not prevent growth decline. These findings challenge current predictions of increasing terrestrial carbon stocks under climate change scenarios”
    From: Recent Widespread Tree Growth Decline Despite Increasing Atmospheric CO2
    Lucas C. R. Silva, Madhur Anand, Mark D. Leithead ,2010

    • I agree. There are a number of variables affecting growth and most species have a preferred zone/region/climate. Although daily/seasonal temp changes are something they’re adapted to, climatic shifts meaning temp/moisture changes outside of their normal bounds may become a limiting factor. Limiting factors can change over time and once stressed some species are slow to recover and may not. Trees of the same species in a lot or area that adapt better could become the survivors and repopulate.

      • Am wondering….many species in temperate and boreal forests are evergreens which means they are transpiring water all year. It’s possible that during Winters that are warmer the moisture loss is increased and the evergreens have a limited ability to slow that down by closing stomata which may lead to stress and tree rings may reveal that. Trees are grand water pumps, esp the Redwoods and Sequoias pumping many thousands of gallons per day up hundreds of feet and out into the atmosphere.

  28. I would think that it is good reasons to be more sceptic to tree rings proxies after 1960. With more acis rain, more pollutions and increased co2 ( with greater stressors), the data is far more difficult to interpret. The greatest problem with Mann`s presentation is perhaps his smoothing of temperatures in the LIA period.

  29. Steve’s objection – ” Steve McIntyre December 6, 2014 at 10:02 pm” came immediately after my comment and I make no apology for what I said. I am sick and tired of the Mannian antics, withholding data, stalling and hiding behind tactical law suits, the labelling of good people and scientists who dare to question Mann’s confection dished up as serious science.
    I just want this farce ended and Mann to feel the way that some of us do, having been ill treated, mocked in a drawn out wasteful process, a process, that does nothing to help those of us that are trying to do our best to improve the lot of those countries and people less fortunate in economic terms.
    My comment was a personal plea. Mann could have ended this farce shortly after the CRU emails became public, the ball was in his court and for me he can for ever remain in that court as the jester or village idiot.
    I appreciate that Steve’s meticulous work is the ideal and proper way to unravel the mess of Mann and I applaud him for that dedication and purpose. It remains to be seen how academia..politicians and the media will respond and recognise his brilliant dissection of data and deduction.
    But the IPCC remains in place and there are determined people involved in framing this debate for political purposes and they do not give a damn for truth, for them propaganda spin and lies are the way to achieve an agenda.
    I am personally tired of the nonsense and the damage to science and scientists.
    When this whole saga is over perhaps we will look back and in time realise that underneath all the shenanigans there has been real progress in unravelling the mysteries of climate, so many fine minds looking at the issues! B,ut for the good of all, this faux “battle” should have been over years ago had the media done its job and agenda put aside.
    Thanks Eric for your articles they are speeding up the process as ordinary people look and decide for themselves.

    • I agree with you Ken, as is apparent from my response to your earlier post.
      Christopher Booker, in the Telegraph, has written an article on the politics of declaring 2014, the ‘hottest’ year on record, and the need to promote this to kepp the gravy train rolling on. See:
      http://www.telegraph.co.uk/comment/11277024/Billions-wont-satisfy-warmists.html
      Mann obviously knew from the divergence issue, that (i) trees are not a good proxy for temperature, and/or (ii) that the temperature record post 1960 was wrong, possibly due to contamination by UHI, station drop outs or corruption caused by incorrect adjustments/homogenisation; and/or (iii), that the divergence is a combination of (i) and (ii). That must be an inescapable conclussion of his work, since it is not that he was unaware of the divergence issue. .
      What is not often commented upon is that in the tuning process, Mann must have tried many different tuning scenarios, and would have gone with the one that best fitted his pre-conceptions, ie., the one, for whatever personal reasons he considered to be the most appropriate. But the fact that different tunings would have resulted in significantly different results only goes to confirm that trees are not good proxies for temperature. He must have realised that from his work on the tuning process.
      Why other scientists are not calling him out, and are not pressing for the record to be corrected is truly shameful, and in the long run there will be severe negative consequences to their turning of a blind eye.

      • Other scientists have reviewed his work. The National Academy of Sciences reviewed the data and concluded:
        “The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century
        warmth in the Northern Hemisphere was unprecedented during at least the last 1,000
        years. This conclusion has subsequently been supported by an array of evidence that
        includes both additional large-scale surface temperature reconstructions and pronounced
        changes in a variety of local proxy indicators, such as melting on ice caps and the retreat of glaciers around the world, which in many cases appear to be unprecedented during at least the last 2,000 years.”
        http://www.nap.edu/catalog/11676/surface-temperature-reconstructions-for-the-last-2000-years
        If you want to publish a peer-reviewed paper that refutes their analysis I encourage you to do so. Until then, I will trust the opinion of a dozen PhD climate scientists over a high-school project and a few bloggers.

      • Streetcred
        I see no reason for your unsubstantiated and unsolicited insult to “ijuts”.
        Richard

  30. And I shall say it again.
    If tree-rings do not measure climate, via world or regional temperatures, then none of dendrochronology can work either. This was my WUWT post, back in 2011.
    http://wattsupwiththat.com/2011/11/23/john-l-dalys-message-to-mike-mann-and-the-team/#comment-806171
    If trees within one small region (Yamal) have such different tree-ring profiles, there is absolutely no chance that you can measure a ship’s beams from Scandinavia or Italy, and compare them with a reference tree growing in Ireland or California. Dendrochronology is pseudo-science at its best.
    Ralph

  31. Instead of all the handwaving above maybe someone (s) should be writing to NATURE( with the proof) to withdraw all of Mann’s work or at least retract

  32. OT but surely this snow cover is way way above normal for Autumm NH 2014
    http://arctic.atmos.uiuc.edu/cryosphere/
    The albedo effect could be devastating (or is it just normal)? On the side it actually looks like at half of the NH is white!! I shiver to think what your winter will be like if this stuff remains there and actually expands more!

  33. The killer blow is when you read Email 1553 which is Briffa forwarding it to our mate Harry.
    http://www.ecowho.com/foia.php?file=1553.txt
    “date: Mon Oct 12 12:10:26 1998
    from: Keith Briffa
    subject: copy to a safe place!!and leave original there
    to: i.Harris@uea”
    Shows that They did not want the email to get circulated.

  34. I have to say that I’m a bit disappointed that falsification was left to a high school project and then ignored. Not only “where was the media?,” but “where were the scientists skeptic or otherwise that should have been looking to test the data and conclusions”? Seems to this non-scientist that they might and should have come up with something similar. It was probably even Mann’s responsibility to test his pet before publication. Oh yeah. I forgot. He’s not a scientist, he just pretends to be a Nobel winning one in court.
    How, in the name of science, does something this false and so openly inviting suspicion by being obviously motivated by opinion. escape appropriate scrutiny in the first place and then get so far? “Tree ring circus” indeed.

  35. Would any arborists care to comment on the effect of increasing CO2 in the atmosphere on tree rings while keeping temperature and hydrology constant? I would think that it would increase the ring width, but that is a wag.

    • I’m only a horticulturalist, which includes forestry, plant sciences, etc., but will take a stab at it. All things remaining constant, which is impossible, but for sake of argument, increased CO2 will enhance tree growth, although that won’t be constant among all species. So, it’s possible the increased growth could reflect in tree ring analysis.

    • I’m an arborist of some 15 years of tree work, and before that I was an orchardist of 15 years of experience in Israel. I raised most stone fruits, apples & pears, walnuts, pistachios and persimmons. The reason for so growing so many species is because our area of the Judean Mountains has an unusual climate and soils and no one was really too sure of what would grow up here. Anyway, In these parts we get no rain whatsoever between April and November so we’re completely beholden to drip irrigation and fertilization via the drip system. When I heard that the Alarmists were correlating tree rings to temperature for a whole year it was such a silly notion to me that I was chortling inwardly for nearly a day of hearing of it. Truth be told that plants and trees need a number of inputs to grow. Among them are water, heat, primary fertilizer elements (N, P & K) along with trace metals such as iron, copper, zinc, boron, magnesium, etc, and sunlight. Changing any one of those inputs will cause greater or lesser growth. Water, either too little or too much, will cause changes in the rate of growth. Temperature increases the metabolic processes of plants, for sure, but if the other inputs are lacking temperature will not be the limiting factor. More or less fertilizer will also influence the width of tree rings.More or less sunlight will also influence the rate of growth. As a farmer here I had control over water & fertilizer as inputs and it’s impressive how much tree growth is influenced by just those 2 factors. In the wild trees may be affected by both grazing animals, such as goats, which can climb into trees and perform a crude pruning that can spur growth OR goats can wreak such destruction that the tree is seriously damaged and that will retard growth. In the wild nearby trees die and rot which will provide fertilizer elements for younger trees so to assume constant inputs of fertilizer is absurd. Grazing animals foraging around trees (assuming that they are sheep or horses which don’t do any damage) will fertilize the area and boost tree growth. And when it comes to tree rings the assumption is that there will only be one ring per year. This last assumption is a far cry from reality, as trees definitely develop new rings after a period of dormancy, but dormancy is not limited to just a winter sleep. Even deciduous trees can go dormant when a drought forces them to drop their leaves in a bid to conserve water, I’ve seen deciduous trees do that here when a homeowner gives barely enough water to their fruit trees in their yard and then a a serious hot spell overtakes us. When the rains or drip irrigation is restored the trees will wake up again and have a growth spurt, and that will produce another tree ring. So it can not be stated with certainty that there’s only one growth ring per year. In sum, to assume that tree growth, expressed in the width of rings, is due only to temperature is one of the silliest notions I’ve ever heard in 30 years of working with trees.

      • But no one is suggesting that temperature is the only factor affecting the width of tree rings. Read the literature and then post an informed comment.

      • Dale,
        You forgot co2!
        I like the bit where you point out

        In the wild nearby trees die and rot which will provide fertilizer elements for younger trees so to assume constant inputs of fertilizer is absurd.

        There is so much that can go wrong. I hear the White Mountains of California (bristlecone pine country) also has herds of Bighorn Sheep, mule deer, marmots and feral horses. I also hear that Bighorn sheep live in large flocks. Take from that what you will.
        http://dwiki.csbs.utah.edu/PDFs/broughton_and_grayson_qr_93.pdf
        http://www.sciencedirect.com/science/article/pii/S0305440383710204

      • I found this comment interesting, so Luke, besides being a prat, what are your other qualifications?

      • Dale
        I would tend to agree with your observations. In Spain where I am, we have had only a few days of modest rain between January and mid October, it is precipitation more than anything else that determines tree growth where trees are not growing on the extreme of habitat survival conditions.
        In my back garden, I have many trees of similarly age (I have seen them growing since small sapplings) and their size, height, girth, how straight they grow, their canopy etc varies enormously although they are sunject tio the same temperatures, but some are in shaddow of other tres at key times of the day, or get little rainfall since they are in shaddow of other trees, or are subject to prevailing winds whereas other are sheltered from prevailing winds etc.
        Had Mann actually watched trees grow, or performed some experiment to see how temperature dependent growth is, he may well have had a very different take on the suitability of tree rings as an acceptable proxy for temperature. .

      • Thanks Dale Baranowski. I have been waiting for a long time for someone to post the suggestion that more than one tree ring a year can occur. Despite Luke’s posts below I do not remember seeing any other dendrologist making this point.
        I farmed fruit in a similar climate for some years. I remember one row of citrus that contained a tree which grew at almost twice the rate of all the adjacent trees from the same batch that had been planed at the same time. It turned out that this particular tree had been planted over the carcase of the donkey, which had towed the cart carrying the saplings and which had died of a heart attack during the planting. The duration of the excess growth did not appear to extend much beyond ten years.
        So far as I have seen in the literature, as applied by climate dendro-climatologists, none of the points that you have made are adequately covered, if covered at all.

        • I have talked to a number of dendrochronologists and have observed them analyzing and quantifying their data. They have known for years that trees occasionally produce two rings/year or may even skip years. These guys (and gals) know what they are doing, none of the objections listed here call into question the conistent pattern of rapid warming in the past 150 years observed in many different kinds of proxy data.

  36. Looking at metrics like the northern tree-line to try to reconstruct the temperature history of the Holocene is actually incredibly interesting. Sad that it’s bogged down in such bitter politics.

  37. We can all say that Michael Mann is a serial fraudster, without fear now, as real science and real data has shown him to be a liar.

  38. Let’s get real folks. The National Academy of Sciences reviewed the data that Mann and others used to reconstruct temperature records over the past 2,000 years. This is their conclusion re Mann et al.’s work:
    “The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century
    warmth in the Northern Hemisphere was unprecedented during at least the last 1,000
    years. This conclusion has subsequently been supported by an array of evidence that
    includes both additional large-scale surface temperature reconstructions and pronounced
    changes in a variety of local proxy indicators, such as melting on ice caps and
    the retreat of glaciers around the world, which in many cases appear to be unprecedented
    during at least the last 2,000 years.”
    John R. Christy was a coauthor on that report (url is below). I trust the opinion of a dozen climate scientists over the report of one high-school student.
    http://www.nap.edu/catalog/11676/surface-temperature-reconstructions-for-the-last-2000-years

    • Luke, you say the NAS reviewed Mann’s data and then you give us a quote, but the quote doesn’t say “we checked out his data and they’re good” it says “a bunch of other people with unrelated data think there’s been exceptional warmth, too”.

      • Wahl and Ammann did a thorough review of Mann et al. in 2007. Here is their abstract:
        Abstract The Mann et al. (1998) Northern Hemisphere annual temperature reconstruction
        over 1400–1980 is examined in light of recent criticisms concerning the nature and processing
        of included climate proxy data. A systematic sequence of analyses is presented that
        examine issues concerning the proxy evidence, utilizing both indirect analyses via exclusion
        of proxies and processing steps subject to criticism, and direct analyses of principal component
        (PC) processing methods in question. Altogether new reconstructions over 1400–1980
        are developed in both the indirect and direct analyses, which demonstrate that the Mann et
        al. reconstruction is robust against the proxy-based criticisms addressed. In particular, reconstructed
        hemispheric temperatures are demonstrated to be largely unaffected by the use
        or non-use of PCs to summarize proxy evidence from the data-rich North American region.
        When proxy PCs are employed, neither the time period used to “center” the data before PC
        calculation nor the way the PC calculations are performed significantly affects the results,
        as long as the full extent of the climate information actually in the proxy data is represented
        by the PC time series. Clear convergence of the resulting climate reconstructions is a strong
        indicator for achieving this criterion. Also, recent “corrections” to the Mann et al. reconstruction
        that suggest 15th century temperatures could have been as high as those of the late-20th
        century are shown to be without statistical and climatological merit. Our examination does
        suggest that a slight modification to the original Mann et al. reconstruction is justifiable for
        the first half of the 15th century (∼+0.05–0.10◦), which leaves entirely unaltered the primary
        conclusion of Mann et al. (as well as many other reconstructions) that both the 20th century
        upward trend and high late-20th century hemispheric surface temperatures are anomalous over at least the last 600 years. Our results are also used to evaluate the separate criticism of
        reduced amplitude in the Mann et al. reconstructions over significant portions of 1400–1900,
        in relation to some other climate reconstructions and model-based examinations. We find
        that, from the perspective of the proxy data themselves, such losses probably exist, but they
        may be smaller than those reported in other recent work.
        and the link:
        file:///C:/Users/Owner/Documents/Downloads/09e4150ba3067d285f000000.pdf

      • Luke,
        I started at the Summary and found this.

        The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This conclusion has subsequently been supported by an array of evidence that includes both additional large-scale surface temperature reconstructions and pronounced changes in a variety of local proxy indicators, such as melting on ice caps and the retreat of glaciers around the world, which in many cases appear to be unprecedented during at least the last 2,000 years. Not all individual proxy records indicate that the recent warmth is unprecedented, although a larger fraction of geographically diverse sites experienced exceptional warmth during the late 20th century than during any other extended period from A.D. 900 onward.
        Based on the analyses presented in the original papers by Mann et al. and this newer supporting evidence, the committee finds it plausible that the Northern Hemisphere was warmer during the last few decades of the 20th century than during any comparable period over the preceding millennium. The substantial uncertainties currently present in the quantitative assessment of large-scale surface temperature changes prior to about A.D. 1600 lower our confidence in this conclusion compared to the high level of confidence we place in the Little Ice Age cooling and 20th century warming. Even less confidence can be placed in the original conclusions by Mann et al. (1999) that “the 1990s are likely the warmest decade, and 1998 the warmest year, in at least a millennium” because the uncertainties inherent in temperature reconstructions for individual years and decades are larger than those for longer time periods and because not all of the available proxies record temperature information on such short timescales.
        http://www.nap.edu/openbook.php?record_id=11676&page=3

        Some of this is not surprising when you consider that much of the Climastrology research public funds tends to be unprecedented!

      • Luke, I also read

        Surface Temperature Reconstructions for the Last 2,000 Years (2006)
        ….Greenland had a pronounced period of warmth around A.D. 1000, a cool period from 1600 through 1900, and a modest 20th century warming. Some coastal sites in Antarctica show 20th century warming but interior sites do not. No Antarctic sites show a warming during medieval times…..

        Some of the claims in that publication are challenged on an ongoing basis by newer and OLDER research too! It has been 8 years since 2006 and as you know people are still researching and looking and bringing in papers that the publication may have missed as well as new findings.
        Medieval Warm Period (Antarctica) — Summary
        Hall et al. (2010), Lu et al. (2012), Bertler et al. (2011), Hall et al. (2006), Williams et al. (2007), Hall (2007)…..
        http://www.co2science.org/subject/m/summaries/mwpantarctica.php
        WUWT posted it up too.
        http://wattsupwiththat.com/2013/04/11/evidence-for-a-global-medieval-warm-period/
        Mann insists that the Medieval Warm Period was regional in the NH. The top link above suggest otherwise.
        How do you thing figs grew in Germany in the Medieval time? That is what Michael Mann used as a reference below.

        Medieval Climatic Optimum
        Michael E Mann – University of Virginia, Charlottesville, VA, USA
        It is evident that Europe experienced, on the whole, relatively mild climate conditions during the earliest centuries of the second millennium (i.e., the early Medieval period). Agriculture was possible at higher latitudes (and higher elevations in the mountains) than is currently possible in many regions, and there are numerous anecdotal reports of especially bountiful harvests (e.g., documented yields of grain) throughout Europe during this interval of time. Grapes were grown in England several hundred kilometers north of their current limits of growth, and subtropical flora such as fig trees and olive trees grew in regions of Europe (northern Italy and parts of Germany) well north of their current range. Geological evidence indicates that mountain glaciers throughout Europe retreated substantially at this time, relative to the glacial advances of later centuries (Grove and Switsur, 1994). A host of historical documentary proxy information such as records of frost dates, freezing of water bodies, duration of snowcover, and phenological evidence (e.g., the dates of flowering of plants) indicates that severe winters were less frequent and less extreme at times during the period from about 900 – 1300 AD in central Europe……………………
        Some of the most dramatic evidence for Medieval warmth has been argued to come from Iceland and Greenland (see Ogilvie, 1991). In Greenland, the Norse settlers, arriving around AD 1000, maintained a settlement, raising dairy cattle and sheep. Greenland existed, in effect, as a thriving European colony for several centuries. While a deteriorating climate and the onset of the Little Ice Age are broadly blamed for the demise of these settlements around AD 1400,
        http://www.meteo.psu.edu/holocene/public_html/shared/articles/medclimopt.pdf

      • Mann:
        “Some of the most dramatic evidence for Medieval warmth has been argued to come from Iceland and Greenland (see Ogilvie, 1991). In Greenland, the Norse settlers, arriving around AD 1000, maintained a settlement, raising dairy cattle and sheep. Greenland existed, in effect, as a thriving European colony for several centuries. While a deteriorating climate and the onset of the Little Ice Age are broadly blamed for the demise of these settlements around AD 1400,”
        Moore et al (2001) says Baffin Island temperatures were highest during the last 1250 years from 1195-1220, at the same time Europe saw a sharp downturn in temperatures. While from the late 14th century the Arctic cooled strongly, but Europe became very warm, especially in 1375 when the most rapid Arctic cooling occurred in the Baffin Island lake samples. The late 10th century was also a very cold period for the mid latitudes.
        So Mann does not seem to realise that the temperatures of the northern Temperate and Frigid zones move in opposition and not in unison. What a hoot!
        It starts with the assumption that the warm period in GISP around 1000 AD was also warm in the mid latitudes. From that error, it is then assumed that all previous warm spikes in GISP were also warm in the mid latitudes, the most laughable being the Minoan Warp Period of ~1350-1150 BC. Which was the period of the demise of the Minoans and several other cultures.
        How do they get away with such nonsense? Did they not even look at the history of the Minoans in Wikipedia?

  39. little bit of common sense would have gone a long way here re tree rings.
    some of us cut wood to survive in the cold. literally life and death issue.
    we saw south facing and north facing slopes (with equal precip and soil conditions) had different ring sizes.
    we also saw years when trees gained more height than width (hybrid poplars good for this) so tree rings made it look like low growth year.
    way too much crap that affects growth to use these things. poor soil, poor brush/tinder control,large canopies, fungus/worms, etc.
    sophomoric idiots with too many letters behind their names.

    • You are right, a lot of factors influence tree ring width including temperature. If you have a sufficient sample size and account for other sources of variation (the main one is precip), the temperature signal is there. As I have suggested to others, I encourage you to reanalyze the data and publish it in a peer-reviewed scientific publication. The data are available on the web.

      • Luke
        My understanding of the scientific method is since Mann claims the “temperature signal” exists, it’s his responsibility to perform (or cite) credible analysis to support the claim.
        Just because you “really believe” in the tooth fairy doesn’t make it real.

  40. Luke, there is a pot of Gold at the end of a rainbow somewhere. There are lots of rainbows, you only have to find the right one(s). Organize a movement to locate and investigate all the rainbows and their ends, and I’m sure you’ll find one with the treasure. Honest!
    Prat.

    • Yes, the rainbows are the data sets. Some very good scientists have taken the time to mine the gold out of those datasets and they have revealed consistent and unmistakable working over the past 150 years. You are welcome to use the data and mine them for the information they provide. Like I said before, reanalyze the data, submit your paper to a peer-reviewed scientific publication and refute the National Academy of Sciences- you will be famous!

      • I have been looking at climate reconstructions since 1960. Mann’s chart is a complete fabrication that contradicts everything before it.

      • Jimbo,
        Note also the slope of the line coming out of the Maunder Minimum, the depths of the Little Ice Age. It’s steeper & makes a bigger move than any phase of the Modern Warm Period.

      • Thank you for your post JImbo.
        We knew that Piltdown was wrong at the time his papers were published (MBH98, etc.).
        I published the following article in E&E in early 2005, in defence of several legitimate climate scientists.
        “Mann eliminated from the climate record both the Medieval Warm Period, a period from about 900 to 1500 AD when global temperatures were generally warmer than today, and also the Little Ice Age from about 1500 to 1800 AD, when temperatures were colder. Mann’s conclusion contradicted hundreds of previous studies on this subject, but was adopted without question by Kyoto advocates.”
        Regards to all, Allan
        Full article at http://wattsupwiththat.com/2011/11/28/the-team-trying-to-get-direct-action-on-soon-and-baliunas-at-harvard/#comment-811913
        Drive-by shootings in Kyotoville
        The global warming debate heats up
        Energy & Environment 2005
        Allan M.R. MacRae
        [Excerpt]
        But such bullying is not unique, as other researchers who challenged the scientific basis of Kyoto have learned.
        Of particular sensitivity to the pro-Kyoto gang is the “hockey stick” temperature curve of 1000 to 2000 AD, as proposed by Michael Mann of University of Virginia and co-authors in Nature.
        Mann’s hockey stick indicates that temperatures fell only slightly from 1000 to 1900 AD, after which temperatures increased sharply as a result of humanmade increases in atmospheric CO2. Mann concluded: “Our results suggest that the latter 20th century is anomalous in the context of at least the past millennium. The 1990s was the warmest decade, and 1998 the warmest year, at moderately high levels of confidence.”
        Mann’s conclusion is the cornerstone of the scientific case supporting Kyoto. However, Mann is incorrect.
        Mann eliminated from the climate record both the Medieval Warm Period, a period from about 900 to 1500 AD when global temperatures were generally warmer than today, and also the Little Ice Age from about 1500 to 1800 AD, when temperatures were colder. Mann’s conclusion contradicted hundreds of previous studies on this subject, but was adopted without question by Kyoto advocates.
        In the April 2003 issue of Energy and Environment, Willie Soon and Sallie Baliunas of the Harvard-Smithsonian Center for Astrophysics and co-authors wrote a review of over 250 research papers that concluded that the Medieval Warm Period and Little Ice Age were true climatic anomalies with world-wide imprints – contradicting Mann’s hockey stick and undermining the basis of Kyoto. Soon et al were then attacked in EOS, the journal of the American Geophysical Union.
        In the July 2003 issue of GSA Today, University of Ottawa geology professor Jan Veizer and Israeli astrophysicist Nir Shaviv concluded that temperatures over the past 500 million years correlate with changes in cosmic ray intensity as Earth moves in and out of the spiral arms of the Milky Way. The geologic record showed no correlation between atmospheric CO2 concentrations and temperatures, even though prehistoric CO2 levels were often many times today’s levels. Veizer and Shaviv also received “special attention” from EOS.
        In both cases, the attacks were unprofessional – first, these critiques should have been launched in the journals that published the original papers, not in EOS. Also, the victims of these attacks were not given advanced notice, nor were they were given the opportunity to respond in the same issue. In both cases the victims had to wait months for their rebuttals to be published, while the specious attacks were circulated by the pro-Kyoto camp.
        *************

  41. Luke says “You are right, a lot of factors influence tree ring width including temperature. If you have a sufficient sample size and account for other sources of variation (the main one is precip), the temperature signal is there.”
    And just how might you “account for other sources of variation”, bearing in mind that they may be related, unrelated or, indeed, change their relationship over time?
    What the serial fraudster, Mann, did was to run all the data he could find against recent temperature series, from far and wide and inevitably found some trees that showed a correlation with some temperature series. They were then given the largest weighting in his subsequent “analysis”.
    It’s called a spurious correlation, just like saying that more people are living longer because they have been watching more television.
    It is not correct, Mann knew it wasn’t correct and deep down, so do you.

    • Then tell me how the National Academy of Sciences in their reanalysis of Mann’s data other data sets got it wrong too.
      The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This conclusion has subsequently been supported by an array of evidence that includes both additional large-scale surface temperature reconstructions and pronounced changes in a variety of local proxy indicators, such as melting on ice caps and the retreat of glaciers around the world, which in many cases appear to be unprecedented during at least the last 2,000 years.
      This free PDF was downloaded from:
      http://www.nap.edu/catalog/11676.html

      • Luke @December 7, 2014 at 8:54 am
        I don’t believe that the committee did a full-scale reanalysis of Mann’s opus.
        From p.115 from the NAP document you linked to above (bold mine):

        Based on the analyses presented in the original papers by Mann et al. and this newer supporting evidence, the committee finds it plausible that the Northern Hemisphere was warmer during the last few decades of the 20th century than during any comparable period over the preceding millennium. The substantial uncertainties currently present in the quantitative assessment of large-scale surface temperature changes prior to about A.D. 1600 lower our confidence in this conclusion compared to the high level of confidence we place in the Little Ice Age cooling and 20th century warming. Even less confidence can be placed in the original conclusions by Mann et al. (1999) that “the 1990s are likely the warmest decade, and 1998 the warmest year, in at least a millennium” because the uncertainties inherent in temperature reconstructions for individual years and decades are larger than those for longer time periods, and because not all of the available proxies record temperature information on such short timescales. However, the methods in use are evolving and are expected to improve.

        Apparently, “plausible” is not exactly “was unprecedented” when one takes the inherent statistical uncertainty into account…

      • D.R. Tucker and Betsy Rosenberg conducted an interview AGW believer Dr. Richard Muller, professor of physics at the University of California, Berkeley in August of 2012. This is what he had to say about the hockey stick:
        Interviewer ”…now that you have validated the information that was in dispute, supposedly, in the Climategate matter, is it fair to say, once and for all, that that is a settled matter, that should be all be [inaudible] and set aside?”
        Prof Richard Muller: “No, no, no. Just the opposite. Actually, that’s not really accurate at all. The data they used in Climategate was proxy data. I wrote a book on the using of that. What they did was, I think, shameful. And it was scientific malpractice. If they were licensed scientists, they should have to lose their license.” [at minute 13:00 in the interview]
        Further in the interview at time 14:30:
        Richard Muller: “What’s wrong is what they said. The conclusions that Michael Mann drew, that it’s the warmest it’s been in a thousand years – I was on an international academy review panel that looked at that. Our conclusion was: he could not draw those conclusions.”
        Here is an mp3 of the interview:
        http://bradblog.com/audio/GreenFront_RichardMuller_080112.mp

      • Luke, you say

        The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years

        You need to remember that this was the ‘conclusion’ that MBH allegedly arrived at. The NAS report merely restated that claim, and added that others subsequently have made similar claims in support of that belief. This is something very, very different than affirming the veracity of such claims. And if you had read further (and indeed cared about the facts, not simply wanted to believe) you would have learnt more about what they actually say.
        Others here have given you similar hints. But more importantly, have you asked yourself why it is that you so dearly want to believe in the Mannian stick? Why is this belief, that you repeat above, so important to you? Why are you so desperate to defend sub-standard work like this?

      • The Mann hockey stick was completely discredited by Wegman’s non-partisan committee (Committee on Energy and Commerce Report).
        The North committee (National Research Council Report) reached similar conclusions as stated below, but attempted to soften its stance and has often been misinterpreted.
        ____________________________________________________________
        Here are some excerpts from the Wegman Report:
        The debate over Dr. Mann’s principal components methodology has been going on for nearly three years. When we got involved, there was no evidence that a single issue was resolved or even nearing resolution. Dr. Mann’s RealClimate.org website said that all of the Mr. McIntyre and Dr. McKitrick claims had been ‘discredited’. UCAR had issued a news release saying that all their claims were ‘unfounded’. Mr. McIntyre replied on the ClimateAudit.org website. The climate science community seemed unable to either refute McIntyre’s claims or accept them. The situation was ripe for a third-party review of the types that we and Dr. North’s NRC panel have done.
        While the work of Michael Mann and colleagues presents what appears to be compelling evidence of global temperature change, the criticisms of McIntyre and McKitrick, as well as those of other authors mentioned are indeed valid.
        “Where we have commonality, I believe our report and the [NAS] panel essentially agree. We believe that our discussion together with the discussion from the NRC report should take the ‘centering’ issue off the table. [Mann’s] decentred methodology is simply incorrect mathematics …. I am baffled by the claim that the incorrect method doesn’t matter because the answer is correct anyway.
        Method Wrong + Answer Correct = Bad Science.
        The papers of Mann et al. in themselves are written in a confusing manner, making it difficult for the reader to discern the actual methodology and what uncertainty is actually associated with these reconstructions.
        It is not clear that Dr. Mann and his associates even realized that their methodology was faulty at the time of writing the [Mann] paper.
        We found MBH98 and MBH99 to be somewhat obscure and incomplete and the criticisms of MM03/05a/05b to be valid and compelling.
        Overall, our committee believes that Mann’s assessments that the decade of the 1990s was the hottest decade of the millennium and that 1998 was the hottest year of the millennium cannot be supported by his analysis.
        [The] fact that their paper fit some policy agendas has greatly enhanced their paper’s visibility… The ‘hockey stick’ reconstruction of temperature graphic dramatically illustrated the global warming issue and was adopted by the IPCC and many governments as the poster graphic. The graphics’ prominence together with the fact that it is based on incorrect use of [principal components analysis] puts Dr. Mann and his co-authors in a difficult face-saving position.
        We have been to Michael Mann’s University of Virginia website and downloaded the materials there. Unfortunately, we did not find adequate material to reproduce the MBH98 materials. We have been able to reproduce the results of McIntyre and McKitrick
        Generally speaking, the paleoclimatology community has not recognized the validity of the [McIntyre and McKitrick] papers and has tended dismiss their results as being developed by biased amateurs. The paleoclimatology community seems to be tightly coupled as indicated by our social network analysis, has rallied around the [Mann] position, and has issued an extensive series of alternative assessments most of which appear to support the conclusions of MBH98/99… Our findings from this analysis suggest that authors in the area of paleoclimate studies are closely connected and thus ‘independent studies’ may not be as independent as they might appear on the surface.
        It is important to note the isolation of the paleoclimate community; even though they rely heavily on statistical methods they do not seem to be interacting with the statistical community. Additionally, we judge that the sharing of research materials, data and results was haphazardly and grudgingly done. In this case we judge that there was too much reliance on peer review, which was not necessarily independent.
        Based on the literature we have reviewed, there is no overarching consensus on [Mann’s work]. As analyzed in our social network, there is a tightly knit group of individuals who passionately believe in their thesis. However, our perception is that this group has a self-reinforcing feedback mechanism and, moreover, the work has been sufficiently politicized that they can hardly reassess their public positions without losing credibility.
        It is clear that many of the proxies are re-used in most of the papers. It is not surprising that the papers would obtain similar results and so cannot really claim to be independent verifications.”
        Especially when massive amounts of public monies and human lives are at stake, academic work should have a more intense level of scrutiny and review. It is especially the case that authors of policy-related documents like the IPCC report, Climate Change 2001: The Scientific Basis, should not be the same people as those that constructed the academic papers.”
        *********************************
        Did Wegman and North Disagree?
        There’s obviously been a lot of spinning here, as Wegman’s language was much more forthright. The realclimate crowd have tried to marginalize the clear statements in Wegman.
        At the July 19, 2006 House Energy and Commerce Subcommittee hearing, Barton asked North very precisely whether he disagreed with any Wegman’s findings and North (under oath) said no as follows:
        CHAIRMAN BARTON. I understand that. It looks like my time is expired, so I want to ask one more question. Dr. North, do you dispute the conclusions or the methodology of Dr. Wegman’s report?
        DR. NORTH. No, we don’t. We don’t disagree with their criticism. In fact, pretty much the same thing is said in our report. But again, just because the claims are made, doesn’t mean they are false.
        CHAIRMAN BARTON. I understand that you can have the right conclusion and that it not be–
        DR. NORTH. It happens all the time in science.
        \CHAIRMAN BARTON. Yes, and not be substantiated by what you purport to be the facts but have we established–we know that Dr. Wegman has said that Dr. Mann’s methodology is incorrect. Do you agree with that? I mean, it doesn’t mean Dr. Mann’s conclusions are wrong, but we can stipulate now that we have–and if you want to ask your statistician expert from North Carolina that Dr. Mann’s methodology cannot be documented and cannot be verified by independent review.
        DR. NORTH. Do you mind if he speaks?
        CHAIRMAN BARTON. Yes, if he would like to come to the microphone.
        MR. BLOOMFIELD. Thank you. Yes, Peter Bloomfield. Our committee reviewed the methodology used by Dr. Mann and his coworkers and we felt that some of the choices they made were inappropriate. We had much the same misgivings about his work that was documented at much greater length by Dr. Wegman.

      • It is not clear that Dr. Mann and his associates even realized that their methodology was faulty at the time of writing the [Mann] paper.

        There’s no way they couldn’t have realized it. They had to create their own “novel” statistical method to get the result they wanted. They had to give one proxy grossly more weight than all the others to get there. That can’t happen by accident.

        • A repeat: One takes a look at the vortex’s and flows and one just has to realize that if there is ANYONE who believes they can model and predict based on the number of variables present is this amazing world of ours is either an idiot, has an ego that will not quit or really needs the money and is willing to sell their soul to sell ice to Eskimos.
          http://earth.nullschool.net/

      • I may be wrong but I think you’re right.
        Why else would he fight so hard to avoid his tax-payer-funded emails related to his work from being released?

      • Plausible is enough for me especially given that so many on this site have said Mann’s analysis was debunked. In addition, the pattern has only gotten stronger with additional data. Mann’s only overstep was making an inference to a short time scale (the decade of the 1990’s and 1998). The overall pattern is clear.

      • Luke
        December 7, 2014 at 12:34 pm
        Plausible is enough for me especially given that so many on this site have said Mann’s analysis was debunked. In addition, the pattern has only gotten stronger with additional data. Mann’s only overstep was making an inference to a short time scale (the decade of the 1990’s and 1998). The overall pattern is clear.

        Uh….Just how can what you said be construed as a reply to dmacleo or me?
        PS “Plausible” is enough for you? Beam me up, Scotty!

  42. “and is still widely reproduced by the more scientifically illiterate alarmists.”
    Because so many of the alarmists are well aware of the fatally flawed hockey stick, having been alerted repeatedly in recent years just as as Mann was warned earlier, it is not their illiteracy causing them to reproduce the stick.
    It is wholesale, institutionalized mendacity which purposefully distributes the falsehoods.
    Unleashed limitless lying has taken hold of countless people in every conceivable position.

  43. Graphic: How We Know We’re Causing Global Warming.
    BY CLIMATE GUEST CONTRIBUTOR POSTED ON AUGUST 10, 2011 AT 10:30 AM UPDATED: AUGUST 24, 2011 AT 4:05 PM
    by John Cook, in a Skeptical Science cross-post.
    http://thinkprogress.org/climate/2011/08/10/286691/global-warming-graphic/
    What’s interesting about this article is what it leaves out. There is no mention of Michael Mann’s “hockey stick” graph. This is because it has been discredited. But the point is this a major reason why the great alarm bells went up about the rate of temperature increase in the second half of the 20th-century. It was known that the global temperatures had been rising for some time, but the hockey stick graph seemed to showed it accelerated grossly in the late 20th century.
    But without this graph the rate of temperature increase is not significantly greater than what had already been happening for hundreds of years, i.e., prior to the time of fossil fuels. Oddly, AGW supporters still keep referring to an “unprecedented” rate of temperature increase without saying what is the evidence for this.
    The reason why they don’t is because the evidence was the hockey stick graph which has now been discredited.
    So it remains like a ghost in their arguments without being specifically stated yet still acting like its conclusions were still true.
    Bob Clark

  44. On the subject of damage done by GW activists.
    Remember this?
    “Justice Stevens delivered the opinion of the Court. (SCOTUS – Mass v EPA 2007). A well-documented rise in global temperatures has coincided with a significant increase in the concentration of carbon dioxide in the atmosphere. Respected scientists believe the two trends are related.”
    “According to the climate scientist Michael MacCracken, “qualified scientific experts involved in climate change research” have reached a “strong consensus” that global warming threatens (among other things) a precipitate rise in sea levels by the end of the century, MacCracken Decl. ¶15, Stdg. App. 207, “severe and irreversible changes to natural ecosystems,” id., ¶5(d), at 209, a “significant reduction in water storage in winter snowpack in mountainous regions with direct and important economic consequences,” ibid., and an increase in the spread of disease, id.,¶28, at 218–219. He also observes that rising ocean temperatures may contribute to the ferocity of hurricanes.” ¶¶23–25, at 216–217.
    One has to wonder what evidence was used to support the “strong consensus”. A “Hockey Stick” maybe?
    This is also the time that CO2 became a “pollutant” rather than the life blood of plant life and life on this planet for those of us dependent on O2.

  45. Temperature aside, ask a typical AGW devotee what is the percentage of carbon in the atmosphere. Rarely do they have an idea and often default into “it doesn’t matter because it is forcing…etc.” Then follow up with how much MAN MADE carbon is in the atmosphere followed by how much of that can man be expected to stop using and when you get to something around a couple of 10,000th of a percent they will give you the finger and walk away.

  46. At what point did Mann know and ignore or avoid mentioning the post-1980 divergence problem? As a “top” tree-ring climatologist, he should have been aware in intimate detail of tree-ring data that showed his premise to be false, that showed his hockey stick graph to be misleading. He hasn’t been updating his work – on purpose?
    Steyn says that Mann has been producing “fraudulent” content for the world, in the legal sense that he is producing material he knows to be misleading and designed for, and resulting in, actions by other people who would not otherwise do so. Even this year, in Britain, his continued use of non-updated graphs has been observed. If he has been not updating his material because it would invalidate the “narrative”, then I would say that Steyn is righter than right.
    Being technically negligent or professionally incompetent is not a crime, but it is cause for censure and the termination of employment. The time-line of Mann and his tree-ring proxies and subsequent opportunities for updating the work is critical to whether fraud has been committed.

  47. Luke, here are some more snippets from your wonderful reference.

    Surface Temperature Reconstructions for the Last 2,000 Years ( 2006 )
    Tree Rings
    1This chapter does not cover the other numerous climatic variables (e.g., precipitation and drought) that can be studied using tree ring records. It also does not consider other environmental factors (such as wildfires) that can be reconstructed from tree ring features.
    http://www.nap.edu/openbook.php?record_id=11676&page=45
    Recommendations to archive all collected materials, so that they remain available for future study, have been published (Eckstein et al. 1984).
    http://www.nap.edu/openbook.php?record_id=11676&page=47
    Although limiting factors controlled tree ring parameters in the past just as they do today, it is possible that the role of different factors at a single location or over an entire region could change over time. This possibility has been raised to explain the “divergence” (i.e., reduced correlation) between temperature and ring parameters (width and maximum latewood density) during the late 20th century (Jacoby and D’Arrigo 1995, Briffa et al. 1998). In Alaska, it appears that increasing air temperature over the past decades is not reflected in increasing tree ring records because water (i.e., drought stress) has become the limiting factor (Barber et al. 2000, Lloyd and Fastie 2002, Wilmking and Juday 2005). In Siberia, on the other hand, reduced correlation of tree ring chronologies with summer temperature has been attributed to increasing winter precipitation, which leads to delayed snowmelt in permafrost environments, thus shortening the tree growing season (Vaganov et al. 1999). Other hypotheses have been formulated for the reduced correlation between temperature and tree ring chronologies, such as a negative effect on tree growth due to greater ultraviolet radiation reaching the ground as a result of thinning stratospheric ozone (Briffa et al. 2004), or the possibility that surface instrumental temperatures are affected by an upward bias (Hoyt 2006).
    …..
    The possibility that increasing tree ring widths in modern times might be driven by increasing atmospheric carbon dioxide (CO2) concentrations, rather than increasing temperatures, was first proposed by LaMarche et al. (1984) for bristlecone pines (Pinus longaeva) in the White Mountains of California. In old age these trees can assume a “strip-bark” form, characterized by a band of trunk that remains alive and continues to grow after the rest of the stem has died. Such trees are sensitive to higher atmospheric CO2 concentrations (Graybill and Idso 1993), possibly because of greater water-use efficiency …..
    http://www.nap.edu/openbook.php?record_id=11676&page=48

    As has been shown above bristlecone pines are responsive to precipitation. They can lie almost dormant during arid times.

    • Yes, there are other sources of variation- especially with tree ring analysis but with sufficient data and careful analyses the warmining signal is cleaar. It is also helpful to look at other data sources (marine, lake, and cave proxies, ice isotopes, glacial length and mass balance records) all of which show the same pattern that Mann et al. found.

      • Luke,
        Mann’s hockey stick was all noise in the shaft. The other proxies are all examined at Climate Audit, very meticulously, and there are problems with all of these.
        You seem quite uninformed on the matter of temperature proxies and their misuse.

      • It’s not the temperature rise that’s the issue, it’s the HOCKEY STICK ‘BLADE’ which forgot the MEDIEVAL WARM PERIOD. That’s the gripe I and many here have.

      • Yes Luke, the warming signal in the last 150 years or so is clear. Even if those data sets have their issues too. But that was not the issue with MBH. (They didn’t even manage to establish that their ‘reconstructions’ managed to recreate the modern warming.) And the real issue is whether they can say anything meaningful about temperatures many centuries even a millennium ago? And with what confidence-

      • Luke,
        don’t forget about Mann’s tree ring failure after 1960. If they responded so well to temperature BEFORE 1960, then what went wrong AFTER 1960? If they are no good after 1960 then what level of confidence should we place on them before 1960? Hung by own petard.

    • Jimbo
      December 7, 2014 at 12:29 pm
      “….or the possibility that surface instrumental temperatures are affected by an upward bias (Hoyt 2006).”
      //////////////////////////////
      This is a useful post since it well describes some of the problems with the data, as well as the reliability and worth of the proxy.
      Ever since Climategate (when I became more interested in this subject), I have been posting comments to the effect that Mann had found something interesting from his studies, and he should have published a paper on the divergence issue, and the implications of the divergence issue and what it suggested. I have frequently pointed out that his study (and data collated by Briffa) supports the view that by the 1960s onwards the land based thermometer record had become polluted by UHI, station drop out and/or incorrect homogenisation/adjustments.
      One should not overlook that whilst the satellite data does not go back to the 1960s, post 1979 through to the run up to the super El Nino of 1998, it shows no warming. Had the satellite been up earlier, it is quite conceivable that it would have shown no warming betwen the 1960s and the run up to the super El Nino of 1998 (especially since there is, in the land based thermometer record, some evidence of cooling post 1940s through to the late 1960s).
      The tree ring data is evidence that there are problems with the land based thermometer record, and I was not previously aware that Hoyt (in the 2006 paper) has noted this very point. It is an important point worth noting, and should be mentioned whenever one considers the reliability and worth of the land based thermometer record.

  48. WATER!

    Abstract –
    Analysis of Radial Growth Patterns of Strip-Bark and Whole-Bark Bristlecone Pine Trees in the White Mountains of California: Implications in Paleoclimatology and Archaeology of the Great Basin
    Dendrochronology focuses on the relationship between a tree’s growth and its environment and thus investigates interdisciplinary questions related to archaeology, climate, ecology, and global climate change. In this study, I examine the growth of two forms of bristlecone pine (Pinus longaeva): strip-bark and whole-bark trees from two subalpine adjacent sites: Patriarch Grove and Sheep Mountain in the White Mountains of California. Classical tree-ring width analysis is utilized to test a hypothesis related to a proposed effect of the strip-bark formation on trees’ utilization of atmospheric carbon dioxide. This effect has grown to be controversial because of the dual effect of temperature and carbon dioxide on trees’ growth. The proposed effect is hypothesized to have accelerated growth since 1850 that produced wider rings, and the relation of the latter topic to anthropogenic activities and climate change. An interdisciplinary approach is taken by answering a question that relates temperature inferences and precipitation reconstructions from the chronologies developed in the study and other chronologies to Native Americans subsistence settlements and alpine villages in the White Mountains. Strip-bark trees do exhibit an enhanced growth that varies between sites. Strip-bark trees grow faster than whole-bark trees, however, accelerated growth is also evident in whole-bark trees but to a lesser degree. No evidence can be provided on the cause of the accelerated growth from the methods used. In the archaeological study, 88% of the calibrated radiocarbon dates from the alpine villages of the White Mountains cluster around above average precipitation, while no straightforward relationship can be established with temperature variations. These results confirm that water is the essence of life in the desert.
    http://arizona.openrepository.com/arizona/handle/10150/193510

    • Sorry, a reference to a WattsUp post is not credible. Show me a peer-reviewed scientific paper that debunks Marcott et al.

      • Who needs a “peer-reviewed scientific paper that debunks Marcott et al.” when MARCOTT DID IT HIMSELF!!! LOL.

        REAL CLIMATE – 31 March 2013
        Summary and FAQ’s related to the study by Marcott et al. (2013, Science)
        Prepared by Shaun A. Marcott, Jeremy D. Shakun, Peter U. Clark, and Alan C. Mix
        Primary results of study
        Frequently Asked Questions and Answers
        Q: What do paleotemperature reconstructions show about the temperature of the last 100 years?
        A: Our global paleotemperature reconstruction includes a so-called “uptick” in temperatures during the 20th-century. However, in the paper we make the point that this particular feature is of shorter duration than the inherent smoothing in our statistical averaging procedure, and that it is based on only a few available paleo-reconstructions of the type we used. Thus, the 20th century portion of our paleotemperature stack is not statistically robust, cannot be considered representative of global temperature changes, and therefore is not the basis of any of our conclusions. Our primary conclusions are based on a comparison of the longer term paleotemperature changes from our reconstruction with the well-documented temperature changes that have occurred over the last century, as documented by the instrumental record. Although not part of our study, high-resolution paleoclimate data from the past ~130 years have been compiled from various geological archives, and confirm the general features of warming trend over this time interval (Anderson, D.M. et al., 2013, Geophysical Research Letters, v. 40, p. 189-193; http://www.agu.org/journals/pip/gl/2012GL054271-pip.pdf).
        http://www.realclimate.org/index.php/archives/2013/03/response-by-marcott-et-al/

      • LOL. Marcott himself admitted to the criticisms against his paper, the published version of which didn’t even match his actual thesis, with no explanation to date as to why. No need to debunk it, the author already did that.

      • Hey Jimbo.

        What Marcott says does not invalidate the reconstruction from 11,000 year bp until 1900

      • David Socrates stated: “What Marcott says does not invalidate the reconstruction from 11,000 year bp until 1900
        Huh? Stopping at 1900 eliminates the 20th century uptick. The graph then would indicate the MWP being warmer than today. It would also indicate that the temperatures from the MWP back 10,000 years are warmer than the MWP.

      • David Socrates
        December 7, 2014 at 3:20 pm
        Hey Jimbo.

        What Marcott says does not invalidate the reconstruction from 11,000 year bp until 1900

        Can you please quote me exactly where I said words to the effect that what Marcott said invalidates the reconstruction from 11,000 year bp until 1900? The issue is with his late 20th century HOCKEY STICK BLADE? Which Marcott disowned. See dating.
        But first can you please explain the cause[s] of one of the two periods of greatest warming in the 20th century 1925–1944? (Phil Jones et al 2010)
        http://wattsupwiththat.files.wordpress.com/2013/03/marcott-a-10001.jpg

    • Postings on WWUT don’t “debunk” anything.

      Show us a peer reviewed scientific paper that debunks Marcott.

      • co2science.org is not a peer reviewed publication.
        ..
        It is a 501(c)(3) non-profit, but then, you don’t know where they get their funding because of that

        Got something from a reputable scientific journal?

      • David Socrates I showed Marcott at Real Climate (in his OWN WORDS) disowning his Hokey Schtick blade. Once he did that there is little left.

      • David Socrates,
        Co2Science is a repository of peer reviewed science. By all means IGNORE their interpretation on anything, but visit the papers where available online by visiting http://scholar.google.com . Simply stating that Co2Science is not peer reviewed is called ‘ducking and diving’ in my book.
        Here are some proxies brought to you by Dr. Michael Mann. Where are these trees and crops today? These proxies cannot easliy be manipulated (unless you use a glass greenhouse). 😉

        Medieval Climatic Optimum
        Michael E Mann – University of Virginia, Charlottesville, VA, USA
        It is evident that Europe experienced, on the whole, relatively mild climate conditions during the earliest centuries of the second millennium (i.e., the early Medieval period). Agriculture was possible at higher latitudes (and higher elevations in the mountains) than is currently possible in many regions, and there are numerous anecdotal reports of especially bountiful harvests (e.g., documented yields of grain) throughout Europe during this interval of time. Grapes were grown in England several hundred kilometers north of their current limits of growth, and subtropical flora such as fig trees and olive trees grew in regions of Europe (northern Italy and parts of Germany) well north of their current range. Geological evidence indicates that mountain glaciers throughout Europe retreated substantially at this time, relative to the glacial advances of later centuries (Grove and Switsur, 1994). A host of historical documentary proxy information such as records of frost dates, freezing of water bodies, duration of snowcover, and phenological evidence (e.g., the dates of flowering of plants) indicates that severe winters were less frequent and less extreme at times during the period from about 900 – 1300 AD in central Europe……………………
        Some of the most dramatic evidence for Medieval warmth has been argued to come from Iceland and Greenland (see Ogilvie, 1991). In Greenland, the Norse settlers, arriving around AD 1000, maintained a settlement, raising dairy cattle and sheep. Greenland existed, in effect, as a thriving European colony for several centuries. While a deteriorating climate and the onset of the Little Ice Age are broadly blamed for the demise of these settlements around AD 1400,
        http://www.meteo.psu.edu/holocene/public_html/shared/articles/medclimopt.pdf

  49. The obvious conclusion that any sane, rational thinking person would come to is if the tree rings “lose correlation” to temperature after 1980, then how can anyone state with any confidence they EVER HAD any correlation to temperature? Anyone that continues to stand behind this frauduent science have zero credability anymore. Unfortunately, it appears the damage is done, as the hokey stick continues to be paraded out time and time again by the warmists.
    Will Mann have to relinquish his Nobel for this?

  50. Luke,
    I learn something new everyday. I have been reading a bit about bristlecone pines (STRIP-BARK and FULL-BARK). Co2 fertilization etc. Luke dear boy, this whole tree ring circus is ‘bristling-cone’ with issue after issue. I think I’ll move on now. Michael Mann’s proxy is a proxy of something other than temperature.

    Climate Audit – Jun 16, 2013
    Not in so many words, of course. However, Briffa et al 2013 took a position on the use of radially deformed tree ring cores that would prohibit the use of strip bark bristlecones in temperature reconstructions, thereby emasculating Mann’s reconstructions. And not just the Mann reconstructions, but the majority of the IPCC reconstructions used by Briffa in AR4.
    http://climateaudit.org/2013/06/16/briffa-condemns-mann-reconstructions/

    http://climateaudit.org/2009/11/16/luckman-at-the-canadian-society-for-petroleum-geologists/

    Abstract – 9 OCT 2008
    The δ13C of tree rings in full-bark and strip-bark bristlecone pine trees in the White Mountains of California
    Dendrochronological work at Sheep Mountain in the White Mountains, CA has demonstrated that bristlecone pine trees in two forms, full-bark and strip-bark, have experienced different cambial growth rates over the past century or longer. The strip-bark trees showed a greater growth increase than the full-bark ones. A calculation of the plant water-use efficiency (W) in response to anthropogenic CO2 released into the atmosphere shows that W of trees in both forms has increased for the past 200 years. However, there is no significant difference between the two tree forms in the rate of increase in W. This implies at least two possibilities with respect to the CO2 fertilization effect. First, the biomass in both tree forms might have increased, but carbon distribution among different parts of a tree was different. Second, the biomass may increase without causing any corresponding change in the plant water-use efficiency.
    http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2486.1998.00204.x/abstract?deniedAccessCustomisedMessage=&userIsAuthenticated=false

  51. I am no scientist, an engineer and i believed most of the ‘ temperature is rising ‘ scare until , Al Gore came out with his move and it started me thinking , something ‘ fishy ‘ here as a perhaps corrupt politician starts flailing the drums i turned to looking for rebuttals and found sites such as WUWT and in couple years realized it was all about the money, just follow the money .

    • I too was alarmed and believed the Climastrologists. Then I had had enough of the alarm and decided to take a closer look, as many here had done. Pooof! I am no longer alarmed and sleep well without worrying about tomorrow. I just do the best I can to convince people not to worry. They are being fooled.

      • The total DOE budget request for Fiscal 2015 is $27.9 billion, up 2.6% from 2014. Of that, spending for “Energy Efficiency and Renewable Energy” is $2.3 billion, up 21.9% from 2014.
        Of that, wind energy research gets $115 million, up 30.5% over 2014; solar power $282 million, up 9.8%; Bioenergy, $253 million, up 9%.
        Total spending on the entire fossil fuel energy program is $711 million, down 8.8%. Of that, spending on clean coal research is zeroed out. I.e., no money budgeted. Of the $711 million, actual spending on fossil fuel energy is $475.5 million, down 15.4%. $205 million goes to the Strategic Petroleum Reserve.
        Most of the $575.5 million of the fossil fuel budget focuses on carbon capture, including the budget for natural gas. “Natural Gas Technologies,” $35 million, up 69.9% “focuses on technologies to reduce the carbon footprint, emissions, and water use …[addresses] high-priority challenges to safe and prudent development of unconventional resources [and evaluates] the occurrence, nature and behavior of naturally occurring gas hydrates and resulting resource, hazard, and environmental implications ” Not a word about research on improving methods actually used for fracking, or helping to actually develop shale gas.
        Carbon capture, carbon storage, “Advanced Energy Systems, which “increases the availability and efficiency of fossil energy systems integrated with CO2 capture” and “Cross-Cutting Research,” which “fosters the development of innovative systems for improving availability, efficiency, and environmental performance of advanced energy systems with CCS“, where CCS is carbon capture and storage, total $243.4 million.
        Fossil energy program direction (salaries) is $114.2 million. So, let’s see: CCS-type programs (243.4) + natural gas hazard amelioration (35) + salaries (114.2) = $392.6 million, leaving $82.9 million (17.4% of the budget) for everything else.
        It’s easy to see where the energy-related DOE emphasis is placed: on ameliorating the presumed consequences of CO2-induced global warming. Huge amounts of money are going there, with virtually nothing to support research where the energy actually comes from.

      • Chapter 4, page 91ff of the DOE budget request provides the projected 2015 outlays for climate science. These are:
        Atmospheric System Research: $26.4 million.
        Climate and Earth System Modeling: $102.6 million, of which $57.2 million is for climate models alone.
        Another $118.9 million is budgeted for climate and environmental facilities and infrastructure.
        That’s $247.9 million for climate science alone.
        And that does not include the money budgeted for improvements in computing (exaflop research), which specifically includes language directed to improving the resolution, complexity, and computational speed of climate models. The total in advanced scientific computing research is another $541 million.
        So, transferring 10% of the exaflop money to climate model computing, it looks like climate science is getting some $300 million a year from the DOE alone.

      • David Socrates
        December 7, 2014 at 3:30 pm
        Jimbo, the $627 million spent by the DOE was not spent on climate change research.

        RESPONSE – Here is the exact DOE page from the Wayback Machine as at 11 August 2011 – the date of the graphic which I posted and which you challenged. They are still funding climate research. Do you still stand by your statement and why??
        http://science.energy.gov/ber/research/cesd/integrated-assessment-of-global-climate-change

        US DEPARTMENT OF ENERGY (DOE)
        Climate and Environmental Sciences Division (CESD)
        Integrated Assessment of Global Climate Change
        The goal is to reveal climate change insights into the complex interactions of human and natural systems and develop the integrated models and tools that will underpin future national and regional decision-making on options for mitigation and adaptation.
        Program Description
        DOE supports research on models and tools for integrated analysis of both the drivers and consequences of climate change. Past work has focused on drivers, specifically sources of greenhouse gas emissions within a common, most often economic, modeling framework. Until recently, only modest attention and resources were devoted to modeling the interactive effects of consequences, that is to say, impacts and adaptation but this has become a major focus for the program……
        Program Funding Opportunity Announcements Funding Opportunity Announcements are posted on the DOE Office of Science Grants and Contracts Web Site and at grants.gov. Information about preparing and submitting applications, as well as the DOE Office of Science merit review process, is at the DOE Office of Science Grants and Contracts Web Site. The most recently closed Announcement (Notice 08-18) focused on basic research and modeling to support integrated assessment of climate change impacts and adaptations.
        http://web.archive.org/web/20110811235455/http://science.energy.gov/ber/research/cesd/integrated-assessment-of-global-climate-change/
        /

    • Lonnie, we are pxing away our children’s heritage on the alter of a false science and Mann led the charge. Let’s take CO2 “emissions” to below 180 and see life on earth disappear. The Maann is a fraud.

      • Norman .
        Agreed .
        We have examples of boondoggles such as ; the Ivanpah three ‘ Towers of Power ‘ fiasco where the principals are begging for a government loan to pay of the government loan .
        Perhaps it can be a monument to future generations of the stupidity of the era , but perhaps they can use the surviving mirrors to direct sunlight at the advancing glaciers.

    • The difference is of interest from a sociological point of view.
      But neither study justifies why tree rings are an acceptable proxy of T at all.
      Why the conclusions affect citability is very interesting, from a history of science point of view.

      • Mann’s reconstruction was dominated by ONE proxy at ONE location in North America. It was overweighted so much that it overwhelmed every other proxy, none of which showed any dramatic modern warming.

  52. This is why D. Socrates doesn’t like the link:
    The results showed that extreme climatic events… such as the Medieval Warm Period, Little Ice Age and 20th Century Warming appeared synchronously with those in other places worldwide.
    Mann’s Hokey Stick chart has been so thoroughly debunked that the IPCC can no longer publish it. And the IPCC LOVED Mann’s MBH97/98 chart. It fit their narrative perfectly. But now all they have are confusing spaghetti charts, which do not have nearly the visual impact of Mann’s chart — which was SCARY. Scary, but fake.
    You can be certain that the IPCC would still be publishing Mann’s scary chart constantly, if they could. But they can’t. It’s been debunked.

    • Dbstealey, when you quote a passage, don’t forget to copy and paste ALL of it….( added the bold to the words you left out)
      ..
      “The results showed that extreme climatic events on the Plateau, such as the Medieval Warm Period, Little Ice Age and 20th Century Warming appeared synchronously with those in other places worldwide”

      • Question for you, David Socrates:
        Did the same climatic events appear synchronously also in Mann’s allegedly ‘global’ reconstruction?
        Or was the ‘importance’ of it rather the opposite?
        Just askin’

      • The LIA is evident in Mann’s work, so is the 20th Century Warming. But there is not a whole lot of evidence that the MWP was global.

      • D. Socrates,
        Here is an interactive world map, showing that the MWP was a global event. Just scroll across any part to see that location and what was found.
        I love these MWP/LIA debates. There are mountains of observational evidence proving beyond any doubt that the MWP happened globally. When Michael Mann tried to pretend that it was just a local, North American event, he was bombared by scientist pointing out that the “consensus” for the past century supported the global MWP because of the immense body of evidence.
        The MWP is not discucced much by the alarmist crowd because whenever they bring it up they get thrashed. They think if they admitted the MWP was global, then Mann’s hokey stick chart would be deconstructed. And they’re right. So they don’t discuss it.
        Mann’s lemmings used to try and make the case that the MWP wasn’t global. They are very foolish to get into that argument, but based on our experience, they keep arguing losing conjectures. So, for every citation claiming there was only a limited, local MWP, I will post at least two (2) links showing the MWP was a global event.
        Ready, Socrates? Ready, Warrenlb? OK! Ready?
        On your markGet setGO!
        ☺  ☺  ☺ 

      • David, your correction makes no substantive difference. dbstealy’s ellipsis was not misleading.
        For evidence the Medieval Warm Period was global see the reviewed and published evidence collected by the Idsos at CO2 Science.
        If Jeffid is around, he can point you to the analysis he published in the AirVent a few years ago, showing that the declining trend prior to the 20th century in the MBH98/99 reconstruction was entirely an artifact of Mann’s PCA method.

      • Mr David Mhoffer
        “So at 4:13 PM you say that the MWP was worldwide,”
        ..
        No, I didn’t say that, I was posting a correction to dbstealey’s quote.

      • Mr Pat Frank

        You are incorrect.
        When you leave out the words “on the Plateau” it changes what “extreme climatic events” refers to.

      • Dbstealey

        The problem with your “interactive world map” is that it fails to show what areas on the globe were COOLER than normal for the time period(s)..

        The problem with your “evidence” is that it is plagued by confirmation bias. You’ve selected only the data that supports your argument, and have left out all the data that contradicts it
        Not to mention that the time scales on the various graphs don’t align

      • D. Socrates says that:
        I have “left out all the data that contradicts” the MWP.
        O really. And what evidence would that be?
        See, the conjecture that the MWP was not a worldwide event is your conjecture, D. Socrates-Grouse, and I note that the total support you have for your conjecture amount to only your own baseless assertions. Your beliefs.
        Sorry pal, that isn’t nearly enough. You don’t like the evidence I posted. Tough noogies, since all you have to counter it is your opinion. And we already know you get your misinformation and your talking points from a low-trafficked alarmist blog with zero credibility. Isn’t it you who keeps trying to post links to Hotwhopper? It’s you. Isn’t it?
        All you do is parrot the opinion of ignorant people who feed you misinformation. When we show you evidence that you’re flat wrong, you deflect, or change the subject, or you just emit more of your baseless opinions. Other commenters have been posting links here. Have you read any of them?
        The link above says: In fact, clear patterns did emerge showing that regions worldwide experienced the highs of the Medieval Warm Period… [we] compiled and examined results from more than 240 research papers published by thousands of researchers over the past four decades. And your CV is… ?
        I think I could post a hundred more papers, and ice core observational evidence, showing the MWP was global — but you would still give your typical response. Tell me, what would it take to convince you:
        1. That CO2 is harmless, and beneficial to the biosphere, and
        2. That there is a mountain of solid evidence supporting the global MWP
        I don’t think anyone could convince you of anything. A new Ice Age could start, and glaciers could cover Chicago again, but you would still be parroting your catastropphic AGW nonsense.
        So tell us: what would it take for you to change your mind? Anything? Or is AGW your religion?
        Time to quit deflecting, and put up your answers.

      • Huang, S., H. N. Pollack, and P. Y. Shen (1997), Late Quaternary temperature changes seen in world‐wide continental heat flow measurements, Geophys. Res. Lett., 24(15), 1947–1950, doi:10.1029/97GL01846.
        Abstract:
        Analysis of more than six thousand continental heat flow measurements as a function of depth has yielded a reconstruction of a global average ground surface temperature history over the last 20,000 years. The early to mid‐Holocene appears as a relatively long warm interval some 0.2–0.6 K above present‐day temperatures, the culmination of the warming that followed the end of the last glaciation. Temperatures were also warmer than present 500–1,000 years ago, but then cooled to a minimum some 0.2–0.7 K below present about 200 years ago. Although temperature variations in this type of reconstruction are highly smoothed, the results clearly resemble the broad outlines of late Quaternary climate changes suggested by proxies.

      • Pat Frank,
        Thank you. I was trying to make a point, that the MWP appeared sychronously, worldwide. But of course D. Socrates completely ignored that, and tried to deflect again. If it weren’t for misdirection [“Look! A squirrel!”] he wouldn’t have much to say.
        As usual, ‘Socrates’ ignores my request for citations, preferring to rely on his assertions instead. No wonder he’s floundering around trying to debate the much more knowledgeable folks here.
        ====================
        SkepticGoneWild,
        Thanks for yet another peer reviewed paper showing that the MWP was warmer than now, and worldwide in extent. Also, the fact that ice cores from both hemispheres, and multiple locations, show that global T rose and fell simultaneously indicates that the MWP was not just confined to one limited area, as Mann’s credulous acolytes believe.

      • Dbstealey
        ..
        Love this graph in your global map…
        ..
        http://pages.science-skeptical.de/MWP/Patterson-1998.html
        ..
        Eight data points covering 1000 years?

        Heavens knows what the calculated variance is on that data set.

        Oh, and another remarkable thing about that map

        No data from Australia ?
        No data from Antarctic ice cores?

        Do you leave these geographical areas out of the map because they don’t fit the confirmation bias?

      • SkepticGoneWild

        “Continental heat flow”

        That measures 30% of the earth’s surface. What about the other 70% covered by water?

      • David Socrates squealed, “That measures 30% of the earth’s surface. What about the other 70% covered by water?
        Hockey stick was northern hemisphere. And last time I checked, trees don’t grow in the oceans. Why aren’t you complaining lack of global data for hockey stick graph?

      • D. Socrates tries to criticize the S&B peer reviewed paper that I linked. Once again, that is nothing but opinion. The paper passed review and was not withdrawn, nor was there a Corrigendum — unlike Mann’s paper.
        ‘Socrates’ can nitpick all he wants, but all it amounts to is impotent cherry-picking like this:
        Eight data points covering 1000 years?
        Yes, and you would snivel about it if it was seven data points, or 77 data points, or 7,000 data points. You are merely a high school graduate looking for something to confirm your alarmist bias. Unfortunately for you, Planet Earth is debunking your globaloney. The planet trumps your Belief System (BS), as you continue to argue against what she’s clearly telling you. I can’t educate you — and neither can Planet Earth.
        I wrote upthread:
        …for every citation claiming there was only a limited, local MWP, I will post at least two (2) links showing the MWP was a global event.
        But you post no citations, you only try to nitpick, deflect, and misrepresent.
        Next, you say:
        Love this graph in your global map…
        Of course, that graph flatly contradicts your Belief, using empirical evidence — something you’re supremely ignorant about.
        Next, you say:
        Do you leave these geographical areas out of the map because they don’t fit the confirmation bias?
        I leave out nothing. I link to sources that debunk your Belief. You can always find a location, or a year, or a measurement that you can claim is missing. But the overwhelming evidence shows conclusively that the MWP was global, and that it was warmer than now.
        You are merely trolling the comments, adding nothing of substance, while I post facts.

      • As usual, Socrates adds nothing of substance. Instead, he merely trolls with the next in his endless series of obfuscating demands, instead of answering questions:
        Any ice core from Antarctica
        This is an ice core record from Vostok, in the Antarctic. Note that temperatures have been declining for thousands of years. And as we see, the surface is also cooling. Even the Arctic has begun cooling.
        Now that’s cleared up, I’m sure we can expect more deflection by the evidence-free trollmaster, Grouse Socrates. Like this:
        OK, tell us. Which ones were cooler? Please provide the peer reviewed… &etc.
        Why should skeptics explainanything? You cannot be educated. That is unpossible. When skeptics debunk your nonsense you simply MovOn to something else, and/or deflect, and/or misrepresent. For example, Pat Frank corrcted you:
        dbstealey’s ellipsis was not misleading.
        But Socrates-Grous is deliberately misleading. He knows my point was that the MWP was ‘synchronous worldwide’. That is why I bolded those particular words. But since Socrates cannot post any credible evidence to support his True Belief in climate catastrophe, he constantly deflects like that. Really, he is getting thrashed with facts in these debates, but he doesn’t even know it. He can’t be educated, and he is out of touch with reality — a typical alarmist True Believer.

      • Thank you very much Mr Dbstealey for posting a link to the Vostok ice core which does not show MWP I guess that is why your global map of all the locations that show MWP does not have one for Vostok.

        Always appreciate when you provide evidence to support my contention.

      • D. Socrates,
        still trolling, I see.
        There is a technique in rhetoric, in which a protagonist finds something not contained in a statement, which is then attacked. You are trying to attack a negative; something that isn’t there. Now we call it trolling, and it is used by trolls, who have nothing else, who use it to deflect from the basic premise: Mann’s tree ring proxy is bunkum.
        You misrepresent again here:
        Always appreciate when you provide evidence to support my contention.
        Nothing supports your contention. You won’t even answer one question about it! As a Mann lemming, you can’t answer questions because the real world would make an even bigger fool of you if you tried.
        You deflected again rather than answering, by demanding an ice core record showing that the Antarctic is cooling. You said:
        Any ice core from Antarctica
        Easy-peasy. I posted an ice core record from Vostok, Antarctica, showing the Antarctic cooling for the most recent several thousand years. You wrongly claim that supports your contention?? heh. As if. You are deluded.
        Start answering questions, and quit being a jamoke. There are at least a dozen from other readers that you’ve completely ignored. You have provided exactly nothing to support your anti-science nonsense; you just continue your despicable rhetoric. So answer a question or two. Or…
        …keep trolling. It’s the only thing you’re good at.

      • Your MWP was global is not helped by the Vostok cores.

        Note also there is no evidence from Australia.
        ..
        Seems to be kind of fishy that the Southern Hemisphere doesn’t seem to be following your “MWP” meme.

      • Trolling, trolling, trolling. Never answering a question. And I know why:
        Because you’ve got nothin’. All you can do is deflect.
        What a jamoke.

      • Again Mr Dbstealey, thank you for posting the link to the Vostok ice cores. As you can tell from the graph, the MWP did not affect Antarctica. You would think that if MWP was global, you’d see evidence of it in the Vostok cores. You are shooting yourself in the foot with that link.
        ..
        So, we have determined that the MWP did not affect either Australia or Antarctica.

        Yes, your MWP seems not to have occurred in the Southern Hemisphere.

      • @D. Socrates,
        I sincerely have trouble answering this question: are you a troll, or are you an idiot?
        Because Vostok is in Antarctica.
        You specifically asked for an ice core record of ‘Antarctica’. That is what I posted for your education. And you could probably find one or two other areas that have sparse data, like Boreo or Haiti. So what? That proves nothing. The fact is that I posted exactly what you asked for: ice core data from Antarctica.
        Your response:
        You are shooting yourself in the foot with that link.
        You are nothing but a troll, Grouse. You fool nobody. You’ve got nothing except your constant deflection and misprepresentation. No wonder you’re getting thrashed in these debates. You have no credible facts, only your despicable rhetoric. Everything you write is deflection.
        Others have also posted a lot of solid scientific evidence here, showing that the MWP was in fact a global event. You cannot refute them, just because you found an area that has less data. You lost the debate, kid. Finish high school before you pretend to understand science. We’re on to you here.

      • Mr Dbstealey.

        You really need to calm down.
        Secondly, you also need to dispense with the name calling. “Troll”, “jamoke” and “idiot” are ad-homimems and clearly show you are unable to focus, and keep to the discussion at hand. I have said to other posters on this site, when dbstealy begins to call you names, you have won the argument.
        Thirdly, Your Vostok graph PROVES that the MWP did not occur in Antarctica

        Lastly, if the MWP was a global event, why is it not in the Vostok cores? Why is there no evidence for it in Australia ?

        Posting the link to that data shows the MWP did not affect the southern hemisphere. Also note that your global map of “evidence” has none for Australia. Just another item proving the MWP did not happen in the SH..

      • D. Socrates says:
        You really need to calm down.
        I’m like I always am. You need to get a productive job. Posting on the internet throughout the workday means you’re not employed. Thus: jamoke, and old Italian-American term for someone who sits in a coffee shop all day, shooting the breeze about everything. Appropriate, no?
        You asked for an ice core measurement that shows global cooling happening. You asked for:
        Any ice core from Antarctica
        I posted one, to help you understand. But you don’t want enlightenment, you’re just trolling. Because you then deflected to Your Vostok graph PROVES that the MWP did not occur in Antarctica.
        See, no matter how much real world evidence we post, you always deflect.
        Next, you say it “proves” the MWP “did not affect the southern hemisphere”.
        Wrong again. It “proves” no such thing. I gave you what you wanted. All it “proves” is that you don’t understand anything about the Scientific Method: see, skeptics have nothing to prove.
        The onus is on you to support your conjecture. But as usual, you have failed.
        Another example of your failure: just because that one particular link did not include Australia means nothing more than it did not include Australia. It does not prove…
        …the MWP did not happen in the SH.
        You are a case study in illogic. From Hubert Lamb on back, the world-wide MWP is a given. It is an established Theory. If you want to falsify it, feel free to give it a try. But the onus is not on skeptics; the onus is entirely on you. So get with the program, and start falsifying — IF you can.
        In addition to mine, Dave Hoffer posted about fifty (50+) links, showing that the MWP was worldwide. Now you, just a high school graduate, come along and pontificate as if you know anything. You don’t.

      • ” You need to get a productive job”

        LMAO…the post calls the kettle black.
        ..
        “Jamoke”…..name calling…pure and simple. Try as stop using the ad-hom argument technique.
        ..
        The ice core you posted doesn’t show any MWP

        “you always deflect.” ….Nope, we’re talking about MWP. Try and focus

        “You are a case study in illogic.” ……I would say calling people names is a case study in “illogic”
        ..
        “Dave Hoffer posted about fifty (50+) links, ” …. none of which show synchronicity.

        ” Now you, just a high school graduate,” another ad-hom? Not only are you violating site rules, you are also wrong to boot!!!!!

    • Socrates,

      Paper
      Dmitri Mauquoy et. al. – 2004
      Late Holocene climatic changes in Tierra del Fuego based on multiproxy analyses of peat deposits
      Our reconstruction for warm/dry conditions between ca. A.D. 960–1020 closely agrees with Northern Hemisphere tree-ring evidence for the MWP and shows that the MWP was possibly synchronous in both hemispheres, as suggested by Villalba (1994).
      http://his.library.nenu.edu.cn/upload/soft/haoli/112/199.pdf

      • David Socrates
        December 8, 2014 at 6:28 am
        “was possibly”

        Not very conclusive.

        Now you look like you’re becoming a sceptic without knowing it! Now look at every new paper that comes out from climate scientists and look out for those caveats – may, might, could………………..

  53. Really? Isn’t it rather the other way around, the modern warming is in fact evidence that the tree rings aren’t temperature proxies? I agree however, that other than that “there is not a whole lot of evidence” .. “in Mann’s work”

  54. David Socrates says “there is not a whole lot of evidence that the MWP was global.”
    According to what?
    There is more evidence of the global MWP than the essentially none for the 20th century warming.
    Unless you think climate models produce evidence?

    • Here is the tabular data GISP2 ice core data:
      ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/isotopes/gisp2_temp_accum_alley2000.txt
      The first data point is listed as 0.0951409 (thousands of years before present). That is 95 years to the nearest whole year. The temperature is -31.5913 degrees C. Now let’s go down in history to 0.964939, which is 965 years before present. This is during what is known as the Medieval Warm Period (MWP). The temperature per the data is -30.46 degrees C. (On the NOAA website, the year 2000 is indicated as ending date, or “present”. So the first data point is the year 1905). So the MWP was 1.1 degrees C warmer than “present”, or 1905. How much has the earth warmed since 1905? According to the IPCC, since 1905, the earth has warmed about 0.9 degrees C (http://www.ipcc.ch/publications_and_data/ar4/syr/en/figure-spm-1.html) So the MWP was about 0.2 degrees C warmer than today.
      Going further back to the year 2.06824 (2,068 years before present), the temperature is listed as -29.57 degrees C. That is 2.0 degrees C warmer than the year 1905, or 1.1 degrees C warmer than today.
      And finally back to the peak of the Minoan warming, year 3.29707 (3,297 ybp), the temperature is -28.748 degrees C. That is 2.84 degrees C warmer than 1905, or 1.94 degrees C warmer than present.

      • ‘present’ in the context of the Alley data is 1950, therefore the first datapoint is 1855. That dataset refers to the Greenland summit where temperatures have risen faster than the global average.

  55. “There are no evidences of moving polar timberline to the north during last century.”

    If this is true, it seems like a very significant point to me. Don’t global-warming enthusiasts claim that plants and species are all migrating northward, and that this is proof that the planet is warming? So why hasn’t the polar timberline moved to the north if the polar region has been warming faster than the rest of the planet? Some say twice as fast, and some, like Cowtan and Way, say that the poles are warming 8 times faster. (When you have very little temperature data from a region, it’s easier to claim anything you want.) But if the polar timberline is not moving, isn’t that pretty strong evidence that the average temperature in that region has not changed much, if any?

  56. David Socrates December 7, 2014 at 6:50 pm
    Dbstealey

    The problem with your “interactive world map” is that it fails to show what areas on the globe were COOLER than normal for the time period(s)..
    >>>>>>>>>>>>>>>>
    OK, tell us. Which ones were cooler? Please provide the peer reviewed studies which confirm them. Seriously, in all the times I have seen this issue debated, not once have I seen someone present a similar list of studies from all over the world using a variety of proxies, that shows cooler than normal during the same time period.

    • Lonie, what a great site. One takes a look at the vortex’s and flows and one just has to realize that if there is ANYONE who believes they can model and predict based on the number of variables present is this amazing world of ours is either an idiot, has an ego that will not quit or really needs the money and is willing to sell their soul to sell ice to Eskimos.

  57. My use of the word “honest” above has since been abused by ignorance. I used “honest” as in “an honest manner”, or “reflecting honest effort”, or “accurate characterization of the original”. I did not say dishonest. I did not mean dishonest. I know what I meant because uniquely in the world, I alone thought of and wrote what I wrote according to my view of the original post. I said what I said unambiguously. It is an intentional and additional misrepresentation to say otherwise and perhaps even dishonest to claim I said the exact opposite of what I said. A claim can be wrong and therefore not an honest representation without being a dishonest claim. In a post rife with mischaracterization I should not be surprised. Moreover it is quite accurate to say a thing is not an honest characterization of something without implying the inaccuracy is the result of dishonesty. I am surprised people of science need to be reminded of this. What I did was agree with what Steve M said. I didn’t say what Steve said, I only agreed with it, so if anyone has a problem with what Steve said then take it up with Steve.
    More to the point I was referring the the original post by Eric above, not Eric personally. I have no way to know if Eric is an honest person or not. I am beginning to believe he has reading comprehension problems. I have Steve’s word the post is not accurate and hence not an honest representation of Steve’s work.
    I repeat: Eric’s post here should be recalled until it is made accurate (honest characterization). And I have no patience for drama queens like Courtney and faux hurt feelings implied by Eric’s response to me. Grow up, boyz.

    • dp
      Whatever you may have intended, what you wrote is clear and unambiguous.
      It is not acceptable for you to fail to apologise to Eric Worral but instead to have provided a verbose diatribe pretending you wrote something other than what you did. Indeed, you have the gall to throw insults instead of apologies and the temerity to repeat your discredited and offensive falsehood saying

      More to the point I was referring the the original post by Eric above, not Eric personally. I have no way to know if Eric is an honest person or not. I am beginning to believe he has reading comprehension problems. I have Steve’s word the post is not accurate and hence not an honest representation of Steve’s work.

      Furthermore, you did not include your post I am answering in the thread discussing your disgraceful behaviour but posted down here where it is away from its context: posting it here and not in context IS dishonest so hypocrisy can be added to your offences in this discussion
      I refer you – and any interested others – to my response to your original and very nasty post and this link jumps to it.
      Richard

      • dp
        You ask presumably yourself

        Is there anything so stupid you’re not willing to say it?

        It would help if when publicly posing such questions to yourself you were also to provide your answers. At present it seems the reason you hide behind anonymity is because there is nothing so stupid you’re not willing to say it when posting as “dp”.
        However, your attempt to switch discussion to consideration of your stupidity is a failure. Your apology is still awaited.
        Richard

  58. The truth is out. Unfortunately the damage has been well and truly done and the sheeple have fallen for it. The plan all along would have been to disseminate the false information to millions of naive public and even more naive students. The truth is what they have made it and the genie refuses into go back into his bottle within a 2 week news grab. Even if the MSM had the cajones to run it.

  59. David Socrates December 8, 2014 at 3:57 pm
    Mr Dbstealey.
    Thirdly, Your Vostok graph PROVES that the MWP did not occur in Antarctica
    Poor choice, lacks the resolution required, try this one instead:
    http://c3headlines.typepad.com/.a/6a010536b58035970c01543695be56970c-pi
    or:
    http://c3headlines.typepad.com/.a/6a010536b58035970c0176161407dc970c-popup

    Lastly, if the MWP was a global event, why is it not in the Vostok cores?
    see above
    Why is there no evidence for it in Australia ?
    Because there are very few appropriate proxies in Australia, so there is no evidence for the opposite either. Nice cherry pick there!
    That said, there’s plenty from the region:
    Peru
    http://c3headlines.typepad.com/.a/6a010536b58035970c0120a94e4b42970b-pi
    South America
    http://c3headlines.typepad.com/.a/6a010536b58035970c01675f6861c7970b-pi
    Chile:
    http://c3headlines.typepad.com/.a/6a010536b58035970c01901ea5a344970b-pi
    New Zealand
    http://c3headlines.typepad.com/.a/6a010536b58035970c0128761b9537970c-pi

    Posting the link to that data shows the MWP did not affect the southern hemisphere. Also note that your global map of “evidence” has none for Australia. Just another item proving the MWP did not happen in the SH..
    Well at worst, I’ve shown that the MWP occurred all around Australia and across the SH, contrary to your claim above. If you find a proxy study showing that there was no warming in Australia, then you’ll have to explain why it is an outlier in comparison to the rest of the world.

    • I was reading a paper about Buttongrass in Tasmania and the archeology mentioned both the MPW and LIA, I’ll try to find a reference but here is a quote:

      In what we call the medieval warm period which is about 1200 to 1500 years ago, there’s a lot more charcoal in some of these bogs from representing more and more fires and therefore the bog probably grew more slowly and during the little ice age which is 1500 to 1850, the amount of charcoal’s less. It looks like climate has a strong control on the fire frequency, this is probably from some Aboriginal intervention in the fire. (GEOFF HOPE, AUSTRALIAN NATIONAL UNIVERSITY)

      • Found this oblique reference to the MWP in relation to Buttongrass . The scientists were actually complaining about the lack of the study of grasses because of a preference for trees and tree rings!! The paper below was referenced:
        COOK E. R., PALMER J. G. & D’ARRIGO R. D. 2002. Evidence for a ‘Medieval Warm Period’ in a 1,100 year tree-ring reconstruction of past Austral summer temperatures in New Zealand. Geophysical Research Letters 29(15)

        ABSTRACT: [1] The occurrence of the Medieval Warm Period (MWP) in the Southern Hemisphere is uncertain because of the paucity of well-dated, high-resolution paleo-temperature records covering the past 1,000 years. We describe a new tree-ring reconstruction of Austral summer temperatures from the South Island of New Zealand, covering the past 1,100 years. This record is the longest yet produced for New Zealand and shows clear evidence for persistent above-average temperatures within the interval commonly assigned to the MWP. Comparisons with selected temperature proxies from the Northern and Southern Hemispheres confirm that the MWP was highly variable in time and space. Regardless, the New Zealand temperature reconstruction supports the global occurrence of the MWP.

    • Sorry Mr. David Mhoffer, but you can’t have it both ways.
      You claim that the Vostok cores “,lacks the resolution ” then you go on to post a chart using the Victoria Glacier ice core. (the second graphic doesn’t mention the study it came from either, not to mention what the units are on the Y-axis)
      Make up your mind about ice cores, or is your confirmation bias the reason you disregard the Vostok core?

  60. A proxy reconstruction, to stick it to the Mann:

    Regardless, the New Zealand temperature reconstruction supports the global occurrence of the MWP.

    COOK E. R., PALMER J. G. & D’ARRIGO R. D. 2002. Evidence for a ‘Medieval Warm Period’

    • Scott, I suggest you look at the diagram on page 215, Fig 4
      http://www7.nau.edu/mpcer/direnet/publications/publications_c/files/Cook-2002.pdf
      Also note in page 214…….
      “The running-RBAR and EPS plots show that the reliability of the chronology is not constant through time. Prior to AD 1200, RBAR declines sharply in one period, but overall the variations in this measure of signal strength are reasonably stable. EPS also remains stable and mostly above 0.85 back to AD 1200 and then declines systematically to a value below 0.50. This result is due to the decline in sample size indicated in Fig. 3 . So for purposes of interpolation the L. colensoichronology is reasonably reliable back to AD 1200 only. Further collections of sub-fossil wood from Oroko Swamp will undoubtedly improve the sample size in the period prior to AD 1500 and thus provide a more reliable record of past climate in the region”
      So, the entire study admittedly is not accurate before 1200 AD
      In their “Disscussions and Conclusions” on page 217 the specifically state….

      “The net result of the calibration exercises shows that Oroko Swamp L. colensoican be used as a reliable proxy of high-summer (i.e. January–March) temperatures for this part of the New Zealand South Island. With the current chronology, this conclusion applies only to the AD 1200–1957 period ”

      So, it not only states that they can’t say anything about what happens prior to 1200 AD, the data they do observe is ” a reliable proxy of high-summer” …..not the whole year.

  61. D. Socrates says:
    the post calls the kettle black.
    What are you talking about? Did you mean the “pot”? If so, I laugh at your ignorance. And I worked for more than thirty years during a highly technical Metrology carreer, designing, testing and calibrating weather-related instruments. I doubt uf you have even heard of some of them. But all you do is post your pseudo-science throughout the workday. So either you’re unemployed, or you are cheating your employer by commenting on blogs, instead of doing what you’re padi to do. Did I leave out any other possibilities? Or are you going to claim that’s what your imaginary employer pays you to do? As if.
    Next:
    The ice core you posted doesn’t show any MWP
    You never asked about the MWP. How many times do I have to point that out? You only asked for ice core data. So now you’re deflecting again, as always.
    And, at Dave Hoffer:
    Make up your mind about ice cores, or is your confirmation bias the reason you disregard the Vostok core?
    More deflection. Why are you afraid to answer his questions?
    Finally, post your CV. You write like a high schooll graduate [“What about Austrial winter…”]. And since you ridicule esteemed scientists, you open yourself up to like criticism. If you don’t like it, post your own CV. Show us you’re their equal, and thus qualified to be critical.
    Finally, as usual you’re chock full of questions. No one can post anything without you nitpicking their comment, until you find something that isn’t listed. Then you pretend what isn’t mentioned somehow cancels everything thay posted. Hoffer posted 50+ links — but you dismissed every one of them with one bogus comment. That is trolling.
    You never answer questions, because if you did, everyone would see how flat wrong you are. So instead, you keep trolling.

  62. Interesting that the divergence starts around 1995 when the AMO warmed. I wonder if there is a similar divergence during the 1925-1965 warm AMO phase?

  63. Late arriving in this discussion, but once again it is necessary to point at the Emperor’s New Clothes…
    “…tree rings demonstrably don’t correlate with temperature.”
    Folks, this realization has tentacles that reach FAR beyond Mann’s amateurish effort to produce an ass-romping paper with his doctorate thesis.
    The entire “science” of dendroclimatology is based on that correlation holding true, or very nearly true ALL THE TIME. But what has happened is that in the 1980s they took a temporary correlation and assumed that the correlation would hold true – for both the past and for the future. .
    What they didn’t wake up to was that even in the 1980s the correlation was disintegrating before their very eyes. It has been falling apart since about 1940, though it wasn’t until the early 1990s that the climate guys and dendroclimatology guys begin to realize that something was amiss.
    BUT AMAZINGLY, they did nothing to question their basic assumption. They assumed that the correlation would right itself pretty quickly.
    A funny thing happened on the way to the Hockey Stick:
    The correlation mismatch got worse and worse, not better and better. They had a proxy that was FAILING, and failing badly.
    Yes, Mike got his pals to falsify the charts, which he had done himself, and they totally assumed that no one was smart enough to catch them.
    But, like I said, that was just the SMALL PICTURE.
    If there is no correlation, then there is no past tree-ring-based temperature record.
    And there also cannot be a FUTURE temperature record based on tree-rings.

    It is a House of Cards, and they have no science in their science.
    Two more things:
    1. The biologists use tree-rings as proxies for PRECIPITATION – AND temperature has been constant. But they can’t do that, according to dendroclimatology, because dendroclimatology has assumed that precipitation has been constant. (What a dumb idea THAT one is…) Thus, two different scientific disciplines assume exactly opposite things about the same evidence (precip is either constant or it is the correlating proxy – or temperature. AT LEAST ONE OF THEM HAS TO BE WRONG. But really, both of them are wrong. Why? Because BOTH temps and precip are variable in the known record and must be assumed variable in the UNKNOWN record, too.
    2. Ice cores… Ice cores are useless in the most recent 200 years or so, so they should play no part in this recent non-correlation of anything whatsoever. Their resolution is very low, plus the fuzziness/vagueness of each one’s starting point makes the top several score layers too ambiguous for use – except in longer-ago times.

  64. I’ve never believed trees are a proxy for a thermometer, and no study has ever proven them to be. So, none of this is surprising.

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