tag:blogger.com,1999:blog-7805174.post6901808900583385792..comments2023-10-19T03:06:44.613-07:00Comments on AMac: Voldemort's QuestionAMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.comBlogger38125tag:blogger.com,1999:blog-7805174.post-68240176774473296572012-07-13T15:27:19.625-07:002012-07-13T15:27:19.625-07:00The comment I left two days ago at RealClimate (11...The comment I left two days ago at RealClimate (11 Jul 2012 at 4:45 PM) (copied upthread <a href="http://amac1.blogspot.com/2011/06/voldemorts-question.html?showComment=1342044210807#c6836760477659783664" rel="nofollow">here</a>) has definitively failed moderation.<br /><br />State-of-the-art paleoclimatology in 2012. Caveat lector.AMachttps://www.blogger.com/profile/08872008617279528583noreply@blogger.comtag:blogger.com,1999:blog-7805174.post-31560645420895381402012-07-11T19:57:20.514-07:002012-07-11T19:57:20.514-07:00The comment I left at RealClimate (11 Jul 2012 at ...The comment I left at RealClimate (11 Jul 2012 at 4:45 PM) has failed moderation thus far, though submissions 45 through 48 have passed since then.<br /><br />Tellingly, RC's owners relegated <a href="http://www.realclimate.org/?comments_popup=6013#comment-240286" rel="nofollow">the following comment by "Benjamin"</a> to "The Bore Hole," despite the cogent and on-topic nature of his remarks.<br /><br />Science as it is practiced by the leading lights of paleoclimatology, and celebrated by the rest of the consensus climatology community.<br /><br />- - - - -<br /><br />I got two questions :<br /><br />1/ The Mann08 you show has no tree rings but still has Tijlander lake sediments proxy, right ?<br /><br />2/ On the Mann08 graph, the post 1900 part is only represented with instrumental record. Is there a version of this graph without the instrumental record but with the proxies used all the way to 2000, like on Jan Esper’s graph ?<br /><br />Thanks.<br /><br />Comment by Benjamin — 10 Jul 2012 @ 3:45 PMAMachttps://www.blogger.com/profile/08872008617279528583noreply@blogger.comtag:blogger.com,1999:blog-7805174.post-7216312070200253832012-07-11T15:11:09.307-07:002012-07-11T15:11:09.307-07:00thanks
best regards, erikthanks<br /><br />best regards, erikAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-7805174.post-68367604776597836642012-07-11T15:03:30.807-07:002012-07-11T15:03:30.807-07:00Anon (July 11, 2012) --
Blogspot ate my response ...Anon (July 11, 2012) --<br /><br />Blogspot ate my response to you. Well, here is what I submitted to the moderation queue in the comments of the July 8th RealClimate post you linked, <a href="http://www.realclimate.org/index.php/archives/2012/07/tree-rings-and-climate-some-recent-developments" rel="nofollow">Tree Rings and Climate: Some Recent Developments</a>.<br /><br />- - - - -<br /><br />AMac says: <br />Your comment is awaiting moderation.<br />11 Jul 2012 at 4:45 PM<br /><br />Prof Mann,<br /><br />In the post, you present panel b of Figure S6 of Mann et al (2008, PNAS). This is the EIV reconstruction of “Northern Hemisphere Land + Ocean.” The current post discusses the blue line (“Full network without tree rings”):<br /><br />[blockquote]<br />if one eliminates tree-ring data entirely from the Mann et al (2008) “EIV” temperature reconstruction (see below; blue curve corresponds to the case where all tree-ring data have been withheld from the multiproxy network), one finds not only that the resulting reconstruction is broadly similar to that obtained with tree-ring data, but in fact the pre-industrial long-term cooling trend in hemispheric mean temperature is actually lessened when the tree-ring data are eliminated…<br />[/blockquote]<br /><br />This reconstruction appears closely related to the one presented as Figure S8 in Mann et al (2009, Science). The legend to that figure notes that when the Tiljander data series are not used, the <i>no-dendro curve</i> fails validation prior to 1500. In addition, post-1500, the <i>no-dendro/no-Tiljander</i> curve (green) and the <i>no-dendro/yes-Tiljander curve</i> (blue) have entirely different shapes.<br /><br />It appears that the portion of the figure that you are discussing with regards to the new Esper paper is entirely dependent on the inclusion of the two (not four) uncalibratable Tiljander data series as paleotemperature proxies in the reconstruction. At this late date, that does not seem to be a reasonable choice.<br /><br />- - - - -<br /><br />My experience with RealClimate's moderation policy has been that my polite and on-topic but critical remarks fail moderation, are subject to excessive delay, or are aggressively bowdlerized. The last time I tried a submission (2011?), my comment failed <i>pre-moderation</i>! The website swallowed the submission without acknowledging it; must've been some neat trick based on a blacklist of user names or IP addresses. Anyway, this one made it onto the queue, in position #45.AMachttps://www.blogger.com/profile/08872008617279528583noreply@blogger.comtag:blogger.com,1999:blog-7805174.post-37698456133262089272012-07-11T14:16:37.788-07:002012-07-11T14:16:37.788-07:00@ Anonymous (July 11, 2012) --
The July 8, 2012 R...@ Anonymous (July 11, 2012) --<br /><br />The July 8, 2012 RealClimate post Anon links is <a href="http://www.realclimate.org/index.php/archives/2012/07/tree-rings-and-climate-some-recent-developments/#more-12427" rel="nofollow">Tree Rings and Climate: Some Recent Developments</a>. It includes a reproduction of panel b of Figure S6 from Mann et al (PNAS, 2008). <br /><br />That panel's legend would be "Comparison of NH mean for combined land+ ocean. Surface temperature reconstructions based on EIV method and using the various proxy networks and target instrumental series as described."<br /><br />The discussion of this Figure in the RealClimate post is as follows:<br /><br />--- begin excerpt ---<br /><br />For example, if one eliminates tree-ring data entirely from the Mann et al (2008) “EIV” temperature reconstruction (see below; blue curve corresponds to the case where all tree-ring data have been withheld from the multiproxy network), one finds not only that the resulting reconstruction is broadly similar to that obtained with tree-ring data, but in fact the pre-industrial long-term cooling trend in hemispheric mean temperature is actually lessened when the tree-ring data are eliminated—precisely the opposite of what is predicted by the Esper et al hypothesis.<br /><br />--- end excerpt ---<br /><br />In other words, as Anon is alluding, Prof Mann is once again discussing a reconstruction -- the blue curve is "Full network without tree rings" -- that <i>depends on the Tiljander data series</i>.<br /><br />In another context -- Mann et al (2009, Science) -- Prof Mann and his co-authors note that without Tiljander, a similar EIV reconstruction fails the validation step prior to AD 1500. See the green and blue lines upthread, in the body of this post. <br /><br />In other words, the shape of the reconstruction Prof. Mann is discussing in this July 2012 RC post is dependent on the use of uncalibratable upside-down Tiljander.<br /><br />If nobody notices, I guess it's okay, especially if the conclusion is on-message.<br /><br />State-of-the-art paleoclimatology in 2012. Caveat lector.AMachttps://www.blogger.com/profile/08872008617279528583noreply@blogger.comtag:blogger.com,1999:blog-7805174.post-85525877122287463832012-07-11T12:45:02.249-07:002012-07-11T12:45:02.249-07:00maybe you'd like to comment on (see the graph ...maybe you'd like to comment on (see the graph labeled b):<br /><br />http://www.realclimate.org/index.php/archives/2012/07/tree-rings-and-climate-some-recent-developments/#more-12427Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-7805174.post-1514062038699605152012-01-07T13:03:57.912-08:002012-01-07T13:03:57.912-08:00Thanks for the link, Anonymous. I've scanned ...Thanks for the link, Anonymous. I've scanned the paper -- interesting! -- and quoted the Abstract at an ongoing discussion re: reconstructions at Lucia's Blackboard, <a href="http://rankexploits.com/musings/2012/galloping-camel-posts-the-wgii-zod/#comment-88406" rel="nofollow">here</a>.AMacnoreply@blogger.comtag:blogger.com,1999:blog-7805174.post-91515957670950857532012-01-07T12:29:29.431-08:002012-01-07T12:29:29.431-08:00Where is the hockey stick?
http://mpra.ub.uni-mue...Where is the hockey stick?<br /><br />http://mpra.ub.uni-muenchen.de/35565/1/Climate_Change_and_Hockey_Stick.pdfAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-7805174.post-30641947237200647572011-12-28T14:29:19.076-08:002011-12-28T14:29:19.076-08:00divergence
http://iopscience.iop.org/1748-9326/6/...divergence<br /><br />http://iopscience.iop.org/1748-9326/6/4/041004Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-7805174.post-35934707672042587062011-12-19T23:16:03.651-08:002011-12-19T23:16:03.651-08:00http://pubs.giss.nasa.gov/abs/sc06400f.htmlhttp://pubs.giss.nasa.gov/abs/sc06400f.htmlAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-7805174.post-74219473974262072632011-07-18T14:17:16.024-07:002011-07-18T14:17:16.024-07:00"the sampling process... is based on a judgem..."the sampling process... is based on a judgement of locations likely to be limited by the env factor of interest--that's why they go near upper or boreal treelines to get a T signal, and lower treelines to get a P signal. But it's not a perfect process, because you don't know for sure how any particular site is responding over time, so its efficacy *has* to be evaluated after the fact--by looking for correlations with the env factor of interest at the closest weather stations (or resident grid cells for gridded data). If the field samplers could choose the right stands without recourse to the climate data comparison step, they would. But they can't. It's exactly analogous to having a set of thermometers of known, varying quality. You're going to pick out the ones you know work the best, and leave the rest behind. Exactly analogous. There's absolutely nothing wrong with it."<br /><br />But we have a very good theory of thermometers. The situation with trees does not seem to me exactly analogous. Treelines change over time for example. Moreover with the bristlecone pines, for example, there is some evidence that the anomalous growth of the ones used in MBH 1998 could have simply been the response to damage. You need to be able to demonstrate that the background factors are being held reasonably constant over the period of the reconstruction. Otherwise how can you be sure your treemometers are not becoming unreliable over past history. Surely the very existence of the divergence problem demonstrates this problem?mikepnoreply@blogger.comtag:blogger.com,1999:blog-7805174.post-70698240882138693382011-07-13T17:37:51.823-07:002011-07-13T17:37:51.823-07:00Jim Bouldin, could you describe how cooler tempera...Jim Bouldin, could you describe how cooler temperatures can be overestimated? I see that warmer temperatures beyond a certain range and tree growth will not be as high. What is the reverse condition, since you can't get negative growth?MikeNnoreply@blogger.comtag:blogger.com,1999:blog-7805174.post-75886907219774216432011-07-10T04:37:53.394-07:002011-07-10T04:37:53.394-07:00TCO said... (July 9, 2011 11:31:00 PM PDT) --
Yaw...TCO said... (July 9, 2011 11:31:00 PM PDT) --<br /><br />Yawn. McIntyre ran a total re-run. Is there anythin new in that post? Even in the comments? Guy has *)&^%$ &^%$**.<br /><br />Oh...and which bitch said that the 4 series were not independent? THIS BITCH DID!<br /><br />:-)<br /><br />- - - - -<br /><br />Well that thread where you and I started by slinging insults ended well, it deepened my understanding of the issue. Still, most of the time, getting personal doesn't appeal to me, so much.<br /><br />Tilj remains little, but sometimes little things can be the entry point for greater insights. Not saying anyone else has to share my interests though.AMachttps://www.blogger.com/profile/08872008617279528583noreply@blogger.comtag:blogger.com,1999:blog-7805174.post-86167747601208621652011-07-09T23:31:49.524-07:002011-07-09T23:31:49.524-07:00This comment has been removed by a blog administrator.TCOnoreply@blogger.comtag:blogger.com,1999:blog-7805174.post-67406866541799547192011-07-09T12:40:25.837-07:002011-07-09T12:40:25.837-07:00last sentence should have been:
"not nearly b...last sentence should have been:<br />"not nearly balanced out by the equally great possibility that cooler temps might have been over-estimated."<br /><br />However, I strike the word "equally". I don't know if they are equal possibilities or not.Jim Bouldinhttps://www.blogger.com/profile/10062200124702011010noreply@blogger.comtag:blogger.com,1999:blog-7805174.post-78470409546231254902011-07-09T09:58:09.381-07:002011-07-09T09:58:09.381-07:00Amac at 4:00:
"There are obstacles to implem...Amac at 4:00:<br /><br />"There are obstacles to implementing this idea, of course. The two big ones, I think, would be assembling an unbiased initial cohort of candidate tree-rings, and figuring out what the 1730-1830 temperature anomaly curve for calibration should be."<br /><br />Definitely correct on the latter. It may be possible for some locations, impossible for others, depending on the spatial properties, and quality, of other available proxies.<br /><br />On the former, you're missing something important. Dendrochronologists *already* +/- do your step 2--that's implicit in the sampling process, which is based on a judgement of locations likely to be limited by the env factor of interest--that's why they go near upper or boreal treelines to get a T signal, and lower treelines to get a P signal. But it's not a perfect process, because you don't know for sure how any particular site is responding over time, so its efficacy *has* to be evaluated after the fact--by looking for correlations with the env factor of interest at the closest weather stations (or resident grid cells for gridded data). If the field samplers could choose the right stands without recourse to the climate data comparison step, they would. But they can't. It's exactly analogous to having a set of thermometers of known, varying quality. You're going to pick out the ones you know work the best, and leave the rest behind. Exactly analogous. There's absolutely nothing wrong with it.<br /><br />Now, however, you *are* onto a couple of important points. One, as I mentioned at Bart's, is the issue of whether your deduced calibration relationships are in fact unique, that is, that the relationship meets the definition of a function. Now THAT is important. The second is the issue of how wide the range of env variable states during the calibration period is. The narrower, the more problematic and the greater the reliance on extrapolation. And one upshot of that is this: there has been an enormous amount of ink spilled about how higher-than-current temps of the past might have been missed (under-estimated), not nearly balanced out by the equally great possibility that cooler temps might over-estimated.Jim Bouldinhttps://www.blogger.com/profile/10062200124702011010noreply@blogger.comtag:blogger.com,1999:blog-7805174.post-46965725772195718542011-07-09T09:14:58.841-07:002011-07-09T09:14:58.841-07:00Jim Bouldin --
Sorry that the filtering trapped y...Jim Bouldin --<br /><br />Sorry that the filtering trapped your comment. These are blogspot's default settings.<br /><br />I've put in your original and removed the duplicates (all hail local copies!). <br /><br />Thanks for the follow-up.<br /><br />.<br /><br />"None" -- <br /><br />I fished your comment out, too. <br /><br />Sorry about that.AMachttps://www.blogger.com/profile/08872008617279528583noreply@blogger.comtag:blogger.com,1999:blog-7805174.post-19534854523027985022011-07-09T09:03:19.823-07:002011-07-09T09:03:19.823-07:00MikeN:
As soon as I read something like "I ...MikeN:<br /><br />As soon as I read something like "I find it frustrating that some dendrochronologists stubbornly see tree ring characteristics as being affected by climate. They are not...", I stop reading. Very confused statement, full of errors, self contradictory. An enormous amount of knowledge exists on the formation of wood--as much as almost any plant anatomy topic, because of the economic value of trees. And there are all kinds of models of tree growth and they include a wide variety of considerations.<br /><br />Plus the typical red flag words: dogma, oversight, weakened credibility, etc. <br /><br />It's a very clueless statement.Jim Bouldinhttps://www.blogger.com/profile/10062200124702011010noreply@blogger.comtag:blogger.com,1999:blog-7805174.post-62446892015697093912011-07-09T08:51:15.213-07:002011-07-09T08:51:15.213-07:00This comment has been removed by a blog administrator.Jim Bouldinhttps://www.blogger.com/profile/10062200124702011010noreply@blogger.comtag:blogger.com,1999:blog-7805174.post-59351851826116031162011-07-09T08:50:35.733-07:002011-07-09T08:50:35.733-07:00This comment has been removed by a blog administrator.Jim Bouldinhttps://www.blogger.com/profile/10062200124702011010noreply@blogger.comtag:blogger.com,1999:blog-7805174.post-14922567046093906152011-07-09T08:48:23.023-07:002011-07-09T08:48:23.023-07:00Test. Something seems to be wrong. I've twice...Test. Something seems to be wrong. I've twice posted a long response and neither time has it showed up.Jim Bouldinhttps://www.blogger.com/profile/10062200124702011010noreply@blogger.comtag:blogger.com,1999:blog-7805174.post-61101425744061199742011-07-09T08:46:41.400-07:002011-07-09T08:46:41.400-07:00This comment has been removed by a blog administrator.Jim Bouldinhttps://www.blogger.com/profile/10062200124702011010noreply@blogger.comtag:blogger.com,1999:blog-7805174.post-37977175018829563542011-07-09T08:06:44.279-07:002011-07-09T08:06:44.279-07:00Amac, MikeN:
A quick note here to say that I'...Amac, MikeN:<br /><br />A quick note here to say that I'm checking in and to clarify some basic points before responding to specific questions and comments.<br /><br />First, to be very clear, I do not consider myself a "specialist" either in dendrochronology or in climatology. I am primarily an ecologist, and as such, have a fairly broad training in a wide range of levels of biological processes, with some background in statistics. That's pretty typical. However, since my dissertation was very nearly a dendro-based topic that I had started, I know more than the average ecologist does about it, enough to make a definite contribution to the field. I've cored my share of trees and read my share of the literature, and in the last year gotten very deeply into the guts of certain analytical procedures. But it's not my "specialty"--that would be the analysis of forest landscape changes since about 1800, particularly in response to land management changes (and more recently, climate changes). The common denominator in what I do, is knowledge of tree biology/ecology.<br /><br />Second, we need to keep in mind that dendroclimatological reconstructions involve several distinct steps: some individuals do all of them and others specialize in only a part of them. There is the data collection step (choosing sites, obtaining the cores, preparing the samples, measuring the ring variables). There is then the detrending step (removing the biological growth trend from each tree core). There are then the (several) steps related to calibration of the rings to the environmental variable(s) of interest (climate, for the present discussion).<br /><br />My work (right now anyway) is centered mostly on the 2nd step (removing the biological trend), with an additional minor (but important) component dealing with the ring to climate calibration step, at the scale of the individual site. These steps are preliminary to any large scale reconstruction steps. Mike Mann (and numerous others) conversely, work entirely on the 3rd step--large scale spatio-temporal reconstruction (also often involving calibration steps). Then there is the other end of the spectrum--the organismal biologists, who specialize on the physisological/environmental mechanisms of radial tree growth (Fritz Schweingruber being perhaps the world's leading expert). So I am working on a different issue than what is commonly discussed in the blog world. And that's because blog world discussions are always some truncation of the full set of challenges we deal with, and often distorted discussions at that, and sometimes highly distorted.<br /><br />So I am somewhere between what Fritz Schweingruber does and what Mike Mann does. I'm trying to reduce the noise that arises from the fact that tree age/size influence ring characteristics and also the noise that arises from considering temperature in isolation from other variables. But it connects in with what Fritz, on one end, and Mike, on the other, are concerned with. You are always going to have specialization, but you need to have people who can bridge between specialties. That is the only way to a robust understanding of any topic in earth/environmental science.<br /><br />The comparison with clinical trials is inherently quite problematic--epistemologically far different. I'll try to speak to that when I get some time. I am extremely busy and responses will likely be very spotty.<br />JimJim Bouldinhttps://www.blogger.com/profile/10062200124702011010noreply@blogger.comtag:blogger.com,1999:blog-7805174.post-22334188979623536412011-07-08T14:05:37.783-07:002011-07-08T14:05:37.783-07:00Jim Bouldin --
As far as the relevance of clinica...Jim Bouldin --<br /><br />As far as the relevance of clinical trials to paleo reconstructions, there is an article in yesterday's New York Times about how an innovative concept seemed to work out well for patients. Eventually, it became clear that the underlying science was flawed, and could <i>not</i> be used as the foundation for good policy.<br /><br />--- Begin fair-use excerpt ---<br /><br />How Bright Promise in Cancer Testing Fell Apart<br />by Gina Kolata - July 7, 2001<br /><br />...First, though, [Dr Minna] asked two statisticians... to check the [Duke group's innovative work.]<br /><br />[They] found errors almost immediately. Some seemed careless — moving a row or a column over by one in a giant spreadsheet — while others seemed inexplicable. The Duke team shrugged them off as “clerical errors.”<br /><br />And the Duke researchers continued to publish papers on their genomic signatures in prestigious journals. Meanwhile, they started three trials using the work to decide which drugs to give patients.<br /><br />[The statisticians] tried to sound an alarm. They got the attention of the National Cancer Institute, whose own investigators wanted to use the Duke system in a clinical trial but were dissuaded by the criticisms. Finally, they published their analysis in The Annals of Applied Statistics, a journal that medical scientists rarely read. <br /><br /><a href="http://www.nytimes.com/2011/07/08/health/research/08genes.html?_r=1&ref=todayspaper" rel="nofollow">continues</a> ...<br /><br />--- End fair-use excerpt ---AMachttps://www.blogger.com/profile/08872008617279528583noreply@blogger.comtag:blogger.com,1999:blog-7805174.post-65413223508387366672011-07-07T01:00:49.749-07:002011-07-07T01:00:49.749-07:00Jim, do you have any opinion on the climategate e-...Jim, do you have any opinion on the climategate e-mail where someone criticizes the various paleoclimate papers for not being based on evolutionary theory? Looking it up, I see evolution was not the primary point.<br /><br />"Since I am neither a dendrochronologist nor a tree physiologist, I have a different take on this little brushfire we have going. I find it frustrating that some dendrochronologists stubbornly see tree ring characteristics as being affected by climate. They are not. They are affected by cambial activity. Cambial activity is affected by internalities of tree behavior, mainly hormonal and nutrient fluxes in the crown. Those things are largely influenced by climatic factors. So there is quite a bit of slack between the climatic factor and the ring characteristic. Is this just negligible static? I doubt it. I see this as an oversight by dendrochronologists that weakens their credibility a tad among those knowledgable about tree growth. I also have a quarrel with the dogma of dendrochology that the cambium changes as the tree becomes senescent. I know of no data that trees senesce -- that is, that they undergo changes due solely to aging. This started as forestry dogma, and was accepted by tree-ringers, who then corrected for it. I'm practically the only one who has systematically looked for evidence of senescence (with a Ph.D. student), and we could not find any in young to ancient bristlecones. But tree physiologists do not generally look at such issues because they have become progressively more reductionist. Nor do they try to produce a theory of tree growth based, as it must be, on evolutionary theory."<br />Some suggest little is known about wood formation on a cellular level.MikeNnoreply@blogger.com