Crowley Unspliced

As a mindless activity, I’ve re-visited the Crowley data, which we’re discussing. Among other stereotypes, out of 15 series, Crowley uses 2 bristlecones, Polar Urals, Tornetrask and Dunde. Even so, without any grafting, there’s not much hockey-stick-ness to this dataset. When you parse Crowley, you also see some very odd decisions, which result in lowering MWP levels relative to modern levels. The image here is a bit cluttered – I’ve been looking at too many spaghetti graphs, but bear with me on it.

Figure 1: Crowley unspliced. Black – base case using 15 proxies; dashed – Crowley’s own edit excluding 2 proxies, which results in higher modern to MWP levels; red – replication using freshly collated data; blue – sensitivity with freshly collated data and i) no bristlecones; ii) no Dunde and iii) no Polar Urals in the 11th century.

I commented before on the "odd" decision by Crowley to exclude the Sargasso Sea and Michigan pollen reconstructions from the proxy composite used for further analysis. He used 13 series, rather than 15 series in his composite. He justified this decision as being due to less precise data – then why mention the other 2 series at all other than as a bait-and-switch. It is impossible not to speculate that, if excluding these 2 series had not had the effect of raising modern levels relative to MWP levels, whether Crowley might have decided the other way. Be that as it may, any robust result should be stable to the inclusion of these proxies and I have included them.

A new point is the curious effect of freshly collated data. As noted previously, Crowley does not provide any data citations and "forgot" where he got data. Crowley only provided smoothed and transformed data, so that digital reconciliation to original sources is not possible and considerable detective work is required to sort out candidate versions. I get the impression that Crowley may have digitized some of these series from print publications as some of them are low resolution series.

I think that it is possible that Crowley may have digitized some series, even where there are digital versions available. For example, I’m confident that Crowley’s "central Colorado" series is a version of the Almagre Mt bristlecone pine series. However, while Crowley’s version has a relatively high correlation (0.82) to a smoothed version of an older archived version of this series (co071), there is a definite dilation of the version from the presumed original data. The archived version has higher MWP to modern levels (surprise, surprise).

Some series can be pinned down even with the sketchy information. Crowley’s "White Mountain" series is an old version of Sheep Mountain, the most dominant series in the MBH98 PC1 – so much for "independence". Why would he use an old version rather than the Graybill version? Print digitzation? The Almagre Mt series is also in MBH; the Jasper, Alberta series is used in Jones et al [1998], but not MBH; the fenno series is Briffa’s familiar Tornetrask reconstruction used in MBH and Jones; the Urals series is Briffa’s Urals series used in MBH and Jones; the SE France series is fran010 used in MBH. The Dunde series is used in MBH and Jones, although the grey version used here seems to be sui generis; I’ve used the most up-to-date version in a fresh collation. The GISP2 data is archived. I used the Crowley smoothed versions for C Michigan sediments; Iceland documentary; C England documentary; German C13 and west China tree ring (Dulan), as I was unable to locate archived versions. A Chinese phenological series from Yang [2002] was used instead of the one from Zhu [1973] since Zhu [1973] is apparently misdated according to Zhang [1994].

The net result of the fresh collation is the red version above, which is close to the composite calculated from the email, but with slightly higher MWP-modern levels.

As a sensitivity study, the two bristlecone series, Dunde and the Polar Urals prior to 1100 (with the misdated cores) were excluded. Even on the red version, the 20th century is similar to MWP levels, but without the very series in question, you have a very distinct MWP relative to the modern period.

If you inspect plots of the individual series, it is interesting how few of them have distinctive 20th century values. the strongest hockey stick shape belongs to the Sheep Mountain bristlecone series, which also dominates the MBH North American PC1. The Central Colorado bristlecone series also has elevated 20th century levels (and contributes to the MBH North American PC1). Thompson’s Dunde ice core series here has elevated 20th century values.

59 Comments

  1. TCO
    Posted Dec 1, 2005 at 10:06 AM | Permalink

    If he used print digitization and did not say so in his description of methods, that is really shoddy. One of the principles of publishing science papers is that you should be clear about all experimental details, especially those which are potentially adverse. You can still publish, no problem. But others looking at the work need to know.

    Not to reveal such details of data gathering/maniupulation in what is essentially a mathematical paper is atrociaous. Like leaving lemmas out of a proof.

  2. TCO
    Posted Dec 1, 2005 at 10:18 AM | Permalink

    And I have walked the talk on this. Have published things where I admitted dropping the sample on the floor (and fought with my advisor) to do so. There is not time or money to repeat/perfect every experiment or study and there is real value in formal publication of all science work. Just make sure that you are honest about it.

    FYI: My approach got my first three papers accepted at quality specialty journals (GRL equivalent) without any revisions or reviewer responses required.* My advisor was flabbergasted as he had published over 100 papers and never had one without revision and had been a journal’s editor for 300 and also never had that happen. Just tell the truth. And that doesn’t even mean you can’t speculate or draw interesting policy or commercial implications. You just have to clearly delineate when you are doing so. It’s just like E. Bright Wilson, Jr. wrote in the 50’s in AN INTRODUCTION TO SCIENTIFIC RESEARCH.

    *And while I was not so controversial as Steve, I did (very directly and strongly) specifically quote, contradict and correct an assertion made by a very bigwig Bell Labs poobah.

  3. John A
    Posted Dec 1, 2005 at 10:59 AM | Permalink

    Whatever reasons Crowley had for excluding the Sargasso Sea proxy (Keigwin et al, 1996) it cannot be for reasons of accuracy or temperature sensitivity. Keigwin went to great lengths to ensure that his two drill cores were properly calibrated by having them analysed at separate laboratories.

    Further Dr Keigwin properly analyzed the relationship between O18/016 isotope ratios and seawater temperature. Where is the analysis of treerings to temperature given in these multiproxy studies?

    In conversation, although Dr Keigwin was leery about whether the MWP was a global phenomenon or not, he did confirm two points as being unambiguous from his study:

    1. The Little Ice Age was clearly a global phenomenon and
    2. The temperature of the seawater in the Sargasso during the MWP was higher than the modern value.

    I also asked him about sediment deposition and stratification, which Keigwin confirmed was not the method used to determine the age of the samples, but the two cores showed that during the LIA, the sedimentation rate was higher. The Gulf Stream transports little sediment, so extra sedimentation indicates drier conditions in NE US and Canada (where the sediment comes from) and with increased storminess during the LIA compared to either the MWP or today.

  4. Paul Linsay
    Posted Dec 1, 2005 at 11:01 AM | Permalink

    Whichever of the three plots is correct, the AGW crowd won’t like it. They all show an approximately steady rise in temperature since 1800. It’s hard to blame warming on CO2 when looked at with this perspective.

  5. beng
    Posted Dec 1, 2005 at 11:04 AM | Permalink

    Steve_M’s runs look more & more like the IPCC’s (less political?) 1990 global temp representation. So for the past 15 yrs, paleo-climate has advanced by some of the most prominent “scientists” finding creative ways to whittle away the humps to a straight line, then graft on a (similarly-treated?) thermometer record, which happens to cover up a recent decline in the proxies.

    Or I guess I’m just daydreaming.

  6. Steve McIntyre
    Posted Dec 1, 2005 at 11:25 AM | Permalink

    re #5: "finding creative ways to whittle away the humps to a straight line" – should we include My Humps (Black-Eyed Peas) as a climateaudit musical theme? Asking the musical question:

    What you gon’ do with all that junk?

  7. Steve McIntyre
    Posted Dec 1, 2005 at 11:45 AM | Permalink

    IPCC 1AR graphic here http://www.climateaudit.org/?p=232

  8. TCO
    Posted Dec 1, 2005 at 11:48 AM | Permalink

    What was the basis of the original IPCC1AR “schematic” diagram, Steve?

  9. Peter Hearnden
    Posted Dec 1, 2005 at 11:52 AM | Permalink

    Re #5. Nope. You’ve found what you want to find. You’ve seen scientists you want to be wrong ‘shown’ to be wrong (on a site that set out so to do). You’ve even convinced yourself they’re (here I’m being polite) untrustworty. You’re with friends :)

    But, do you read RealClimate? Or the relevant Wiki pages? Or the more recent IPCC reports? Or any of a shed full of papers in Nature or Science or other? Well, I suspect your criticism and dismissal of them knows no bounds – but, hey, go on, surprise me!

  10. Brooks Hurd
    Posted Dec 1, 2005 at 12:02 PM | Permalink

    The greatest drama clearly comes from making the LIA appear to have “normal” temperatures. If the MWP can be minimized, it heightens the drama. Mann’s Hockey Stick does this quite well.

    It helps if you can have the CO2 increase track the dramatic temperature increase. This was done by adjusting the age of ice core gas so that the ice core CO2 data is basically consistent with the Hockey Stick. This requires an assumption that the ice core gas is actually 70 or more years younger than the ice in which it is contained.

    The AGW proponents point out that both CO2 levels and temperatures have been increasing dramatically since late in the 19th Century. If, as these reconstructions show, temperatures have been rising since the early 19th Century, then this rise occurs roughly 75 years before the increase in CO2 levels which the AGW folk say is the cause if the temperature increase. It appears to me that the AGW folks have manufactured their own quandary.

  11. beng
    Posted Dec 1, 2005 at 12:24 PM | Permalink

    *****Peter says:
    But, do you read RealClimate? Or the relevant Wiki pages? Or the more recent IPCC reports? Or any of a shed full of papers in Nature or Science or other?
    *****

    Yes, Peter, I’ve read SurrealClimate & alot of papers, for a long time. I was interested in this in the early 1980s long before it was much in the news.

  12. Brooks Hurd
    Posted Dec 1, 2005 at 12:33 PM | Permalink

    Re: 9
    Peter,

    But, do you read RealClimate? Or the relevant Wiki pages? Or the more recent IPCC reports? Or any of a shed full of papers in Nature or Science or other?

    Yes, yes, yes, and yes.

    I have questions on all of these. Typically I ask authors questions about papers whenever I can. Normally they are happy to answer my questions.

    I can not even pose many questions on RC because they will not appear. I have asked Mike and William various questions via email. Mike does not reply, but William does. I do get answers to the questions that make it on to RC, but this leaves many questions unanswered.

    Certain authors do respond to emails. Parker has answered my questions. Some other authors either do not reply (Mann) or do not answer questions. Where is Jones’ data?

    When I have answers to my questions, I learn things that I did not know. When people refuse to answer questions, it causes me to ask “why?”

    When we are being asked to spend countless billions of dollars to control global warming, why can we not see all the data and methodologies that led the policy makers to reach to reach the conclusions that they made in the Kyoto Treaty?

    Why Peter?

    Aren’t you also curious why all this data is such a closely guarded secret?

    I have lived in or near the capital cities of 7 different countries on 3 continents. My personal experience has led me to conclude that politicians are the same everywhere. I am more than a little cynical about the political decision making process after watching countless scandals unfold. I do not trust politicians to tell us the truth about why they did something. There is always a hidden agenda. Therefore, I want to understand what motivated them to make certain decisions. I can only understand this if I have the facts available to me.

  13. Spence_UK
    Posted Dec 1, 2005 at 1:13 PM | Permalink

    Re #9

    Have we just found “what we expected to find”? Did Mann just find “what he expected to find”? That is a sword that cuts both ways.

    Who knows what the answer is, although if you read the comment from Hans von Storch on Prometheus, you will see that a respected climate scientist is of the view that we have not yet successfully resolved the paleo temperature record, the hockey stick probably caused publication bias, and its inclusion in the SPM was “stupid”.

    We have a well respected climate scientist broadly agreeing with many of the things Steve, and others on this site, have said. So your various fallacious appeals to authority are starting to break down: it is clear the opinion of the “experts” is divided.

  14. Terry
    Posted Dec 1, 2005 at 8:47 PM | Permalink

    I always appreciate it when you show the individual series as you do in this post. It gives a very clear feel for what is actually in the data. By picking a statistical method that focuses on one rather than the others you can prove almost anything here.

  15. John Cross
    Posted Dec 1, 2005 at 9:31 PM | Permalink

    Re #10: Brooks, is that the old claim by Jaworowski?

    John

  16. Peter Hearnden
    Posted Dec 2, 2005 at 1:51 AM | Permalink

    Re #11, so was I!

    Re #12 “Aren’t you also curious why all this data is such a closely guarded secret?” I think you’re a victim of your own propaganda. This place is stacked high with data that’s beeen gone over in excruciating detail in the hope of finding errors.

    Are you a supporter of the Jaworowski ideas? If you are then oh dear…

    Re #13 – old chestnut. No one thinks anyone of the recons to be spot on – in that sense *I* broadly agree with Steve. Many people accept they’re on the right tracks – indeed only by excluding ‘uncomfortable’ data are they otherwise.

  17. Brooks Hurd
    Posted Dec 2, 2005 at 2:24 AM | Permalink

    Re: 15
    John,

    Do you mean the age of the gas versus the age of the ice core? This is not Jawarowski’s claim. Gas age adjustment is described in detail in Karsten 2004 “Chemical and physical analyses of firn and firn air.” Refer to chapter 5, page 124 which has a table with the corrected gas ages as calculated by Karsten.

  18. Brooks Hurd
    Posted Dec 2, 2005 at 2:30 AM | Permalink

    Peter,

    This place is stacked high with data that’s beeen gone over in excruciating detail in the hope of finding errors

    And Jones data is just where exactly? I really would like to see it. I don’t mean the calculated anomolies on his web site, but the actual data.

  19. epica
    Posted Dec 2, 2005 at 4:10 AM | Permalink

    #10
    The gas age – ice age difference is really well know physics. Check for literature by Severinghaus/Caillon and others. It depends on temperature and accumulation rate and its effect on gas concentration can be measured directly (works of Battle and Bender). Some sites might have 70 years some much larger differences. The very small about 10ppm fall and rise of CO2 during the LIA in Law Dome (if a robust result) shouldn’t contribute much to the LIA variation. The statement that there was some fitting of the ice age/gas age to the hockeystick (Etheridge published 1996) is even for the standards what is usually written here absurd.

  20. epica
    Posted Dec 2, 2005 at 5:14 AM | Permalink

    #10 Sorry the LIA CO2 amplitude is probably less than 5ppm (depends a bit from where to where you are measuring it) in LAW Dome in the D47 record its even harder to identify it anyway.

  21. Mathijs
    Posted Dec 2, 2005 at 7:54 AM | Permalink

    I have a question. Why is everybody still discussing whether the medieval period was slightly warmer or slightly colder than mid-20th century? I was curious how todays temperature measurements would fit in the picture that was presented above, and found out its scaling is a bit deceptive. I matched time and absolute temperature as good as I could, and while the above figure didn’t quite match with 20th century measurements (!), I gave it the benefit of the doubt wherever possible. The result you can see at http://www.phys.uu.nl/~romans/comparison.jpg.

    Care to comment?

  22. Posted Dec 2, 2005 at 8:03 AM | Permalink

    Hi matthijs

    Compare the above with a recent glacier proxy.
    http://www.ncdc.noaa.gov/paleo/pubs/oerlemans2005/oerlemans2005.html

    Oerlemans, J. 2005.
    Global Glacier Length Temperature Reconstruction.
    IGBP PAGES/World Data Center for Paleoclimatology
    Data Contribution Series #2005-059.
    NOAA/NCDC Paleoclimatology Program, Boulder CO, USA.

    ORIGINAL REFERENCE: Oerlemans, J. 2005.
    Extracting a Climate Signal from 169 Glacier Records.
    Science, Vol. 308, No. 5722, pp. 675-677, 29 April 2005

  23. Steve McIntyre
    Posted Dec 2, 2005 at 9:11 AM | Permalink

    #21: Matthjis, one of the main issues for proxy studies is whether the so-called “proxies” are capable of measuring warm temperatures. Thus, one would like to see proxies benchmarked against the warm 1980s instead of ending in the 1970s or 1980s. The silence here is breathtaking. For example, Hughes did new bristlecone measurements at Sheep Mountain in 2002 and has not reported them – if they showed warm 1990s, what do you bet that we wouldn’t have heard about it by now? If the tree ring proxies do not continue to respond to higher temperatures, then there is no guarantee that they would have picked up a warm 11th century. Such evidence as does exist suggests that tree ring levels in the 1990s were not anomalous.

    One starts to notice a transitioning in the proxies that one hears about – now we mostly hear about glacier retreat rather than tree rings as the proxy de jour.

  24. epica
    Posted Dec 2, 2005 at 9:13 AM | Permalink

    #21 The warmer/colder-MWP question is interesting for 1) attribution of climate change and 2) to know the sensitivity of the system to small forcing (solar,volcanism). The rest of your question I dont understand. What is the problem with scaling?

  25. Spence_UK
    Posted Dec 2, 2005 at 9:16 AM | Permalink

    Re #16 – how can it be an “old chestnut”? The comment was posted just over a week ago.

    You seem to be suggesting that von Storch was referring to the uncertainty bands associated with paleo temperature reconstructions. I don’t know how you can put that interpretation on his comment. The language used by von Storch seems pretty clear to me: in his view, the hockey stick has been rejected as a meaningful temperature reconstruction. Not “has some uncertainty associated with it”. The word he used was “rejected”.

    Your perennial argument here is that we non-climate scientists shouldn’t be questioning the “professionals”. Well, here we have a well respected climate scientist rejecting the hockey stick. Now suddenly your response is “Many people accept they’re on the right tracks” – appeal to authority replaced with appeal to popularity – suddenly climate scientists views are not good enough? Von Storch had an answer for this as well: pointing out the publication bias caused by the hockey stick. This suggests that, since 1998, we have gone down tracks dictated by MBH, which has now been “rejected”.

    PS. Peter, If you want to discuss von Storch’s comment in more detail, we probably ought to move it to the correct thread – my fault for bringing it up in here.

  26. epica
    Posted Dec 2, 2005 at 9:58 AM | Permalink

    #23 Many proxies show warmer conditions than today, though sometimes on much longer time scales. I can give you a list, if you want, including some which were used for Holocene climate reconstruction. Are you suggesting that there are physical or physiological thresholds making detection of temperature warmer than 20th centuries mean temperatures impossible?

  27. Brooks Hurd
    Posted Dec 2, 2005 at 10:40 AM | Permalink

    Re: 19

    Epica,
    Thanks for pointing out my misstatement. What I meant to imply was that there was some rationale behind adjusting the gas age. A simpler assumption would be that the gas and ice were the same age. The gas age adjustment does bring some of the ice core CO2 measurements into a closer agreement with the Mona Loa instrument data. That was what I meant.

    The physics is well known that gases can diffuse through firn. If one concludes that gas concentrations at the firn/ice boundary are similar to those in the current atmosphere, then I believe that one must also make several assumptions. One is that the diffusion path must be relatively consistant. There can not be any significant diffusion barriers, such as layers of crust, in the firn. One must also assume that in spite of the large surface area of the firn, there are neither significant surface effects nor diffusion into the firn itself. By significant, I mean any effect which could change gas concentrations as the gas diffuses through the firn.

  28. Brooks Hurd
    Posted Dec 2, 2005 at 10:51 AM | Permalink

    Re: 22

    Hans,
    I wonder how Oerlemans decided on his weightings of the proxy sets. His data does not shed much light on this since it is only the composite anamolies.

  29. Steve McIntyre
    Posted Dec 2, 2005 at 11:27 AM | Permalink

    Re #26: my point is related mostly to tree ring proxies which underpin the key 1000-year multiproxy studies that I’ve specialized in: MBH99, Jones et al 1998; Crowley and Lowery 2000; Briffa; Esper etc. The tropical ice core dO18 seem to have different issues. On a full Holocene scale, people move away from tree rings and polar ice core dO18 tends to be used more obviously. Is this what you had in mind?

  30. Dano
    Posted Dec 2, 2005 at 12:22 PM | Permalink

    For example, Hughes did new bristlecone measurements at Sheep Mountain in 2002 and has not reported them – if they showed warm 1990s, what do you bet that we wouldn’t have heard about it by now? If the tree ring proxies do not continue to respond to higher temperatures, then there is no guarantee that they would have picked up a warm 11th century

    Steve, you’d begin to appear credible to the community if, instead of your little carpie-carping about something for which you have no information and can only speculate, you’d back up your implication with actual data. Get some cores.

    You can’t really wonder any more why you get no cooperation (nobody is that dense), and things like this are a big signal about what you’re up to.

    Best,

    D

  31. Ray Soper
    Posted Dec 2, 2005 at 1:28 PM | Permalink

    What a strange comment Dano. Surely the point is that certain people are claiming that bristlecones are a good proxy for temperature, but don’t seem to be able to provide the evidence for that proposition.

  32. Steve McIntyre
    Posted Dec 2, 2005 at 1:31 PM | Permalink

    Dano, nice of you to drop by. I know precisely what it feels like to have bad drill results and, under such circumstances, how much you want to delay reporting in the hopes that you get a good drill result. I also know precisely what it feels like to get a good drill result and how quickly you want to report it. People who understand speculative mining ventures know that delays in drill results very seldom bring good news. Now for mining promotions, you have legal obligations to issue your results. You can’t wait for 3 or more years to report your results. You’re right that I don’t "know" what the Sheep Mountain results. However, I’ve got quite a lot of experience with drill programs and I trust my judgement in such matters. I would be totally blown away if Sheep Mountain ring widths were off the charts through 2000.

    I don’t expect cooperation. I expect people to archive data under any and all applicable requirements and I expect funding agencies and journals to enforce their policies. When have I ever "wondered" about people’s behavior? It’s quite rational for these people not to want anyone to look at it critically. It is especially rational for people whose methods and data selection are not up to best standards.

    My experience and skills are on the math and statistical side. There are lots of other people who are interested in collecting tree cores, but it’s also important to reflect on the statistical aspects of this and I think that I can make a better contribution there.

    BTW, not all climate scientists have quite the same animosity as realclimate authors. I was asked to be an IPCC 4AR reviewer. I’ve received several invitations to have dinner or drinks with respected scientists at AGU next week. I’d be happy to have a drink with any realclimate authors as well.

    But the provision of data and methods should not depend on whether people like one another. To the extent that that’s how climate science works, I am trying my best to change it. If people don’t like being criticized for not archiving data and methods, then the cure is simple : just do it.

  33. John G. Bell
    Posted Dec 2, 2005 at 1:41 PM | Permalink

    Dano,
    Actually I think M & M getting a lot of traction. For a while it looked like climate science had been more or less permanently hijacked.

    As to “… things like this are a big signal about what you’re up to.”, what Steve is up to is science. You don’t seem to know what that is or you’d have recognized it. I’m not saying this to tweak your tail but in all sincerity.

    Time to get to know yourself. You won’t be able help save the world until you do.

  34. John G. Bell
    Posted Dec 2, 2005 at 2:59 PM | Permalink

    Dano,
    My last post was over the top. Sorry about that.

    Glad the bison left you alone. I always took particular care not to be too much on their mind. We had tourists, mostly European, get into serious trouble with them. Ours are truly wild and that’s a great thing.

    Anyway I wish you well and apologize.

  35. Terry
    Posted Dec 2, 2005 at 3:43 PM | Permalink

    Dano and Steve:

    Updating the proxies is really the acid test of this whole debate. If recent temperatures are truly unprecedented, then contemporary proxy results should be consistently unprecedented as well, so contemporaneous proxy results would end this debat once and for all. If they are consistently off the charts, then it would show that 1) the proxies are able to detect high temperatures, and 2) that current temperatures are unprecented. If they are not, then either 1) the proxies are unable to detect temperatures as high as they are now and so the failure of historical proxies to detect high temperatures in the past proves nothing, or 2) current temperatures today are not abnormally high and the thermometers that say they are are wrong.

    The climate community should be screaming to update the proxies and resolve this issue. The folks at RealClimate should be clamoring to get the new data to silence the skeptics once and for all.

    In fact, young researchers have a chance to make a name for themselves here. Simply publish a paper NOW predicting the proxy data based on the temperature data. When the new proxy data come in the predictions are spot on, the paper will be endlessly cited for decades to come. Such a paper is astonishingly obvious — after all, there are many at RealClimate who are certain that 1) the current temperature record is accurate, and that 2) the proxies are excellent measures of temperature. It would be child’s play to write such a paper. In fact, it sounds like just a few afternoons of work.

    Steve. Why don’t you write such a paper? If phrased neutrally, it is a can’t-lose proposition. Simply frame it as “if the proxy studies are right and if the temperature record is correct, proxy results for the years 1990 – 2005 should be in the range of x to y.” Then, when the proxy results actually came in, everyone would have to cite your paper as to whether their results fell within the predicted range.

  36. Steve McIntyre
    Posted Dec 2, 2005 at 5:50 PM | Permalink

    RE #35: not a bad idea. It would be amusing to do this for this bristlecones at Sheep Mountain since we know that there is information currently being withheld.

    I agree entirely about post-1980 proxies and have posted on post-1980 proxies from time to time, more back in Feb or March. Look at right-bar category. D’Arrigo et al are mooting an upside-down U quadratic relationship to temperature. Briffa has complained for some time that post-1960s MXD results aren’t working and hypothesizes some unknown anthropogenic factor. Quotes from him are surreal – after making this hypothesis, he considers himself able to disregard the modern results.

  37. Dave Dardinger
    Posted Dec 2, 2005 at 6:02 PM | Permalink

    Terry,

    Your analysis leaves out one very important 3rd possibility for the case where the proxies don’t match the present temperatures.

    3. The supposed proxies aren’t really proxies at all and the supposed agreement was just a artefact of the methods used and/or experimenter bias.

    Actually there’s a similar #3 for the case where the updated proxies still match current data, but such a finding would reduce the chances of that being the case.

  38. John A
    Posted Dec 2, 2005 at 6:36 PM | Permalink

    I’d have to agree with Dave. If tree rings are able to measure temperature then I’d like to see the evidence.

  39. John Cross
    Posted Dec 2, 2005 at 7:01 PM | Permalink

    Brooks:

    Thanks for the reference to the Firn ice thesis. It is now on my reading list for when I get a chance. However for now I confess that I don’t follow your point about the gas age. TO me it sounds like the start of the Jaworowski argument, but this is a fairly well known physical phenomena. To quote from your your reference:

    The Law Dome ice core results (Figure 1.1.5) reveal that the atmospheric
    CO2 concentration has increased dramatically (~30%) since 1750 A.D.
    Other ice core records [Neftel et al., 1985; Raynaud and Barnola, 1985;
    Etheridge et al., 1988; Wahlen et al., 1991; Barnola et al., 1995] from Antarctica
    as well as Greenland show similar increases for methane and CO2. The CO2
    increase is likely caused by biospheric releases (land use changes) and fossil
    fuel use, starting with the industrial revolution at about 1850 A.D [Pearman et
    al., 1986; Siegenthaler and Oeschger, 1987]. The growing industry was not only responsible for increasing concentrations of greenhouse gases (CO2 and
    methane), but also for the introduction of other gases, like chlorofluorocarbons
    (CFCs), that have a large influence on the climate system. The CFCs are
    responsible for the hole in the ozone layer, as was recognized in the 1987
    Montreal Protocol, and also act as greenhouse gases. To investigate the effect
    of industrial growth in more detail, the history of other trace gases needs to be
    studied as well.

    He doesn’t seem to have any problem with the CO2 record but appears to be interested in using firn ice to capture larger volumes of air for trace gas analysis.

    Regards,
    John

  40. Terry
    Posted Dec 3, 2005 at 9:24 AM | Permalink

    Re #36:

    Steve:

    You are proably right that any predictions should focus on only a single proxy series. The PCA analysis is such a meat-grinder (mushing all the series together in very complicated ways) that it may not be possible to reliably invert the process to go from temperatures to proxies. Attacking it one series at a time sounds much more tractable.

    Perhaps it is sufficient to do a simple analysis that maps temperatures to proxies using only the period for which thermometer data is available. It sounds like this could be as simple as a regression analysis of proxy readings on temperature. Projections (with attendant confidence intervals) could then be made based on the most recent temperature data. A nice xy plot of proxy readings v. temperatures would be very powerful. (It could become as iconic as the hockey stick itself.) Include the regression line and put the predictions with confidence intervals in red on the plot too. It would be hard to argue with something that simple.

    Sounds easy. Let’s do it. How about a co-authorship? It has to be done before the new proxy data is made public to avoid any suspicion of reverse engineering and ad-hocery.

  41. Terry
    Posted Dec 3, 2005 at 9:43 AM | Permalink

    Steve:

    No reason this couldn’t be done for all the proxies. Let’s do the bristlecones first and get that up, then go on to the others later. Looks like some series won’t have a significant relationship, but that’s ok — the confidence intervals will just be so wide that it is obvious those proxies have no power to predict temperature.

  42. beng
    Posted Dec 3, 2005 at 11:04 AM | Permalink

    This is somewhat OT on this thread, but Terry brings up good overall points.

    Another potential “groundbreaker” seems available for climate scientists. We already have a CO2 increase from ~1800 to present where CO2 has gone from 280 to 375 ppm, and at least some semblance of actual thermometer readings over that period, albeit sparse spatially. From that, we could very roughly get a “real” (not proxy) indication of climate sensitivity in terms of the usual “doubling-CO2″ scenario. I wonder why this hasn’t been done? Or has it, and it’s been buried by the climate community/media industry?

    I don’t buy the usual “there’s hidden warming in the pipeline” reason. The transient responses of the 1998 El Nino & earlier Pinatubo volcano show that. You can’t store much “heat” in below-surface ocean waters ’cause it’s colder than the surface! The only areas where that would have an effect would be in areas of ocean-upwelling.

  43. JerryB
    Posted Dec 3, 2005 at 1:20 PM | Permalink

    “some semblance of actual thermometer readings” might be an optimistic way to characterize available historical records of themometer readings.

    For example, in the collection of temperature records called the Global Historical Climatology Network (GHCN) there are over 250,000 conflicts of 0.5 C, or larger, of reported monthly means of over 2,000 locations.

    There are many pitfalls for the unwary user of such records.

  44. Posted Dec 3, 2005 at 4:51 PM | Permalink

    About updated proxies: Probably the longest series ever made of tree rings is from Lapland (North Sweden/Finland), 7,500 years long and updated until 2001. There is a definitive downward trend at the end of the curve, somewhere since 1950 (it’s a rather coarse graph…). See Pages, page 15. If you look at the graph, one can wonder if there is any correlation between tree rings and temperature anyway…

    Further, the same issue has some more interesting articles about 14C deposits / solar strength (page 14), sediments and climate (page 10-12 – it looks like that we are heading towards a new ice age!) and several problems encountered in instrumental data series (page 9-10)

  45. Jeff Norman
    Posted Dec 4, 2005 at 3:02 AM | Permalink

    Re:#43

    Jerry,

    Could you please expand on these conflicts?

    Jeff

  46. JerryB
    Posted Dec 4, 2005 at 8:58 AM | Permalink

    Jeff,

    The overview of the GHCN at http://www.ncdc.noaa.gov/oa/climate/research/ghcn/ghcnoverview.html , particularly sections 2 and 3, will give you some background on why the records may include multiple means for same location/months.

    I ran a program to sift through a recent GHCN “raw” monthly means file, and report occurrences of different recorded means for same location/month. A small sample report is at http://www.john-daly.com/bigdif/multidat.ge4 . which includes conflicts of 4.0 C, or larger.

    A variant of that program, with the cutoff set at .ge. 0.5 C, reported 254,649 occurrences. I can upload a zip file (about 2 meg) of that report, and/or the current version of the program, if you, or others, would like.

  47. the fist
    Posted Dec 6, 2005 at 7:08 AM | Permalink

    John Cross
    I noticed on Lambert’s site you were boasting that people feel you are an annoyance on this site. This is what you said:

    “…………. on Climate Audit, someone just implied that I was almost as obnoxious as Tim. Maybe that makes me an honorary sock-puppet”

    Do you get some sort of orgasmic like kick out of being thought of as annoying dick? Or, do you have a personality/behavioural disorder that needs treatment? I know it digresses from the topic, but if you don’t have a sack allowing you to behave like a man instead of the girly whisperer, why bother coming to this site? Unless of course it’s to disturb the conversation thread with inane comments meant to rattle other peoples chains.

    You obviously show no desire to learn new things rather than the Soviet swill we read about climate change and how we are going to perish due to heat exhaustion, or freezing cold as I recently read ( reminding me of the heads you lose, tails I win scenario)

    In other words Lambert atracts a good number of dicks on his site. Why not pout your chest like lambert and the rest of those wankers and stay there? I hope it doesn’t offend you as that is not my intention.

  48. John Cross
    Posted Dec 6, 2005 at 9:42 PM | Permalink

    Fist: Thanks for the laugh. I have printed off your post and given it to my wife for use next time she thinks I am getting too full of myself. However if you were trying to insult me I warn you that worse has been said about me and probably by my mother.

    But, might I suggest that instead of ad-homing those who disagree with you, you find something specifically wrong with what I have said and comment on that.

    In regards to posting on this site, if Steve wishes me not to post I will abide by his wishes (as I have done in the past when he made a similar request about a topic).

    Regards,
    John.

  49. ET SidViscous
    Posted Dec 6, 2005 at 10:17 PM | Permalink

    Am I the only one who is tired of the term “ad-hom”

    It’s only used on those who you disagree with first of all. Why can’t we use the simpler or more generic terms “disagree” or “insult” Why do we need to be so high falutent

    there is a time and a place for the term. When Mann writes a published paper attacking Steve, or vice versa and the term “His grasp of the topic is less than complete.” that’s an ad-hominem attack.

    One someone on a blog/forum/internet board calls someone a dumbass that’s an “insult”

    Painting a turd white doesn’t make it an accent piece.

  50. John G. Bell
    Posted Dec 6, 2005 at 11:07 PM | Permalink

    Re #49, ET
    I don’t get your point. We have no english word that can replace ad hominem.

    Appealing to personal interests, prejudices, or emotions rather than to reason.

    9 letters for that concept, not 66, is a good trade.

  51. ET SidViscous
    Posted Dec 6, 2005 at 11:33 PM | Permalink

    My point would be that it’s highly overused, particuarly in climate change discusions.

    And your definition would apply to points like “Industry funded” which is “Appealing to personal interests, prejudices, or emotions rather than to reason.” however, a term like “annoying dick” is an insult, no matter how valid teh insult may be.

  52. the fist
    Posted Dec 7, 2005 at 6:25 AM | Permalink

    John
    It wasn’t meant to make you laugh. It was meant to help you see what kind of weasel you are. Pitter pattering off to tell Lambert you are turning into an obnoxious twit “just like Tim” is not my idea of pillow talk with my wife. Then again, these days who am I to judge what is considered good pillow talk in the modern modern age.

    Seeing you brought up your private life, tell us, when you read her your quoted words about how great it is being thought of “as abnoxious as Tim” did she look even remotely aroused or did she exhibit a look of horror before she turned away with the comment “I’ve got a headache tonight, Honey”.
    Sorry to bring up an image of your private life but you brought out in the open first.

    Regards
    The fist

  53. the fist
    Posted Dec 7, 2005 at 6:27 AM | Permalink

    Oh John
    And Sid right. Call me rude, callous whatever but leave his El hombre? vrap for those who can use it an appropriate manner, otherwise abnoxious shouldn’t be left by itself.

  54. Peter Hearnden
    Posted Dec 7, 2005 at 7:21 AM | Permalink

    snip

  55. ET SidViscous
    Posted Dec 7, 2005 at 7:45 AM | Permalink

    Dude come down. I was talking about the usage of Ad-hom, the quoting of your line was only the first available blatant example of a flat out insult.

    I would have said the same thing but used “Prick” instead of “Dick”. “Dick” is so 70’s

  56. John A
    Posted Dec 7, 2005 at 10:15 AM | Permalink

    Of course for purely immature trolling then I would introduce ‘Peter’ ‘Hearnden’ ‘farmer’ ‘and’ ‘climate’ ‘expert’

  57. Armand MacMurray
    Posted Dec 7, 2005 at 1:08 PM | Permalink

    Since it’s pretty clear this thread went off the tracks starting with post #47, perhaps John A or Steve could close it? It’s cluttering up the “Recent Comments” list.

  58. the fist
    Posted Dec 7, 2005 at 4:59 PM | Permalink

    Peter:
    Instead of worrying who said what, isn’t it better to simply concern yourself with what was said? If you think I am trolling simply because I brought to attention Cross’s strange behaviour then you aren’t that much better than he is.

    Getting on his knees in front of Lambert trying to impress him by saying he too is thought of as obnoxious dickhead makes me think he is not here to post anything other than something annoying. Isn’t that troll like behaviour?

  59. John A
    Posted Dec 7, 2005 at 5:27 PM | Permalink

    re #49

    I’d have to agree. This comment thread is a slow trainwreck.

    If Steve wants it unblocked let him do it himself.

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