Review of Osborn and Briffa [2006]

Osborn and Briffa [2006] , published today in Science, cannot be considered as an “independent” validation of Hockey Stick climate theories, because it simply re-cycles 14 proxies, some of them very questionable, which have been repeatedly used in other “Hockey Team” studies, including, remarkably, 2 separate uses of the controversial bristlecone/foxtail tree ring data.

Also even more remarkably, they have perpetuated the use of Mann’s erroneous principal components method in one of their key proxies.

Peer reviewers and editors at Science have failed to ensure compliance by Osborn and Briffa with journal data archiving policies, a frequent defect in paleoclimate reviewers for Science, as data for the study is not archived, nor is much of the source data.

Of the source data which is archived, some is password protected, presumably for international security. Within the available record, many peculiar inconsistencies can be observed affecting both this study and Esper et al [2002], a study previously published in Science also with a non-existent data archive.

Not only are the 14 proxies used in O&B not independent of prior studies, in fact, they are composed entirely of proxies repeatedly used in previous studies. Astonishingly, 2 of the 14 proxies (2 of only 10 in the Medieval Warm Period) are bristlecone/foxtail pines, despite the fact that these are precisely the proxies that have most been called into question in connection with the work of Mann et al.

Nor are Osborn and Briffa independent authors. Both are members of a group of scientists, self-identified as the Hockey Team. They have both recently co-authored a reconstruction with Mann, Bradley and Hughes [Rutherford et al, 2005], and their close associate, Philip Jones, has co-authored still other studies with Mann. Rutherford et al. [2005] is cited, but footnote (13) fails to disclose their co-authorship.

Briffa is lead author on millennial reconstructions for the IPCC 4th Assessment Report, presently under review. Von Storch (see ) has queried the propriety and wisdom of IPCC using review authors who are engaged in controversy in the literature on a personal basis and end up reviewing their own work (as happened with Mann in IPCC TAR).

The IPCC has failed to ensure that the assessment reports, which shall review the existing published knowledge and knowledge claims, should have been prepared by scientists not significantly involved in the research themselves. Instead, the IPCC has chosen to invite scientists, who dominate the debate about the considered issues, to participate in the assessment. This was already in the Second Assessment Report a contested problem, and the IPCC would have done better in inviting other, considerably more independent scientists for this task. Instead, the IPCC has asked scientists like Professor Mann to review his own work. This does not represent an “independent” review.

Here we have another instance — this time with Briffa. The IPCC practice seems particularly unwise in this case, since the offering from Osborn and Briffa is weakly argued.

The O&B article vividly illustrates the weakness both of peer reviewing and editorial decision-making in the paleoclimate area at Science, the prominent journal presently reeling from the Hwang stem cell scandal. It highlights a failure to implement their own policies on data archiving and failures to verify claims in the article itself.

Data Archiving and Versions
On paper, Science has exemplary data archiving policies (see, which seem to require paleoclimate authors to provide an archive sufficient to replicate their results:

Science supports the efforts of databases that aggregate published data for the use of the scientific community. Therefore, before publication, large data sets … must be deposited in an approved database and an accession number provided for inclusion in the published paper.

In multiproxy paleoclimate studies, it is essential to archive the data as used even if the data appears to be in the public domain (since versions can vary), but this is not done here. This failure is exacerbated because O&B rely on 5 series from a study previously published in Science [Esper et al, 2002], where Science also failed to require data archiving, and on 1 proxy [Yang et al., 2002] which relies on 2 ice cores by L. Thompson also published in Science (Dunde, Guliya), on which no information was archived prior to my requests to another journal (Climatic Change). I have been trying for a considerable period of time to get Science to require these authors to archive the data from the earlier studies, but these efforts have so far proved unsuccessful. The difficulties of trying to track down “grey” versions are vividly illustrated just with reference to Science publications.

Yang et al. [2002] relied on a “grey” 50-year smoothed version of the Dunde and Guliya series. Unfortunately, these versions are dramatically inconsistent with the 10-year smoothed versions archived at my request last year (see In order to reconcile the versions, one needs to examine sample information, which Science has thus far been unable to obtain. Because of various problems with the Yang et al [2002] composite, Jones and Mann [2004] decided not to use it. It is rather a surprise, to say the least, to see it re-surface here in O&B.

The versions of the Esper series are also impossible to sort out. Esper et al [2002] did not provide an ITRDB identification for the Tyrol series; the identification number provided by O&B has data extending only to 1827 — which is inconsistent with Figure 2 and which would make validation of this series impossible. For the Quebec tree ring series (series 4), O&B cite Schweingruber (cana169) as a primary source for Esper et al [2002], while Esper et al [2002] acknowledge Payette and Ilion for data (who studied other sites). O&B say that the Quebec series ends in 1947, while the data in cana169 goes to 1989. There are many other similar problems.

Much of the underlying tree ring width measurements data is unarchived, affecting the following series: Yamal, Tornetrask, Taimyr, Icefields, Boreal, Upper Wright. Some of this information has been generated by the European Union “SOAP” project, financial support from which is acknowledged in the article. Osborn and Briffa head up this project. Civilians in the climate wars will undoubtedly be astonished to think that password security would be applied to tree ring data. However, this is the case (see ). Briffa has refused my requests for access to the password protected tree ring data.

Proxy Quality Control
O&B assert that they carried out quality control on the proxy records to ensure that each proxy was correlated to gridcell temperature. They singled out Soon and Baliunas [2003] for allegedly failing to carry out such quality control procedures, although the same criticism should equally be brought against Mann et al [1998] who not only used precipitation series as temperature proxies, but even used French precipitation series for American gridcells (“The rain in Maine falls mainly in the Seine”). One can only imagine the vituperation that would have issued had Soon and Baliunas committed a similar blunder, and we likewise wonder at how the supposed quality control procedures in place for Mann et al. [1998] failed to identify such an obvious blunder.

In McIntyre and McKitrick [2005a, 2005b], Ross McKitrick and I pointed out the extraordinary dependence of the MBH98 (and MBH99) reconstruction on bristlecones/foxtails and pointed out many reasons why world temperature history should not be based on their ring widths. It is astonishing, therefore, to see the bristlecone/foxtails dominating not just one, but two proxies in O&B. Since 4 proxies do not extend back to the MWP, they make up 2 of 10 in the MWP.

It is beyond astonishing that O&B series 1 uses the discredited MBH principal components methodology [see McIntyre and McKitrick, 2005a, 2005b and endorsements of this aspect of our criticism in von Storch and Zorita, 2005 and Huybers 2005]. Jones and Mann [2004] used the MBH98 principal components methodology, together with a curious and undocumented splice.

Although O&B reported that they carried out quality control on the Esper sites (resulting in the rejection of 4 sites for not having correlation to temperature–Mackenzie, Gotland, Jaemtland and Zhaschiviersk), they do not report similar quality control being carried out on either the PC1 from Mann and Jones [2003]/Jones and Mann [2004] and simply repeat their claims of a decadal temperature correlation of 0.52. Jones and Mann [2004] also claimed an annual correlation of 0.20 for this proxy.

This claim is obviously at odds with Lamarche et al. [1984] and Graybill and Idso [1993], who stated that the post-1900 pulse in bristlecone growth was uncorrelated to temperature. In this case, the quality control for the 6 sites can be readily checked as the 6 chronologies are all publicly archived, as is the HadCRU2 temperature dataset. (Collations are provided at Our check yielded very different results.

For the period 1870-1980, only one of the six sites had a even a slight positive correlation to gridcell temperature on an annual comparison (Sheep Mountain: 0.03), while the other sites all had negative correlations ranging from –0.14 to –0.36. The correlation of the MBH98-type PC1 to a weighted average of gridcell temperatures (weighted identically as the PC1) was –0.12. The undocumented “adjustment” of the PC1 in Jones and Mann [2004] increased the correlation somewhat, but only to 0.03. These results are obviously at odds with the quality control claims.

The results, decadally smoothed, were little better: only one positive relationship (Sheep Mountain 0.06) while the others had negative correlations ranging from –0.11 to –0.32. For the MBH98-type PC1 against the weighted gridcell average similarly smoothed, the correlation was –0.35 (“adjusted -0.26).

So that there is no misunderstanding of the mismatch, the “fixed” PC1 and the gridcell temperatures are illustrated in Figure 1 below.

Figure 1. Red: Mann and Jones “fixed” PC1 (O&B series 1); black — weighted average of gridcell temperatures. Top — annual data; bottom — decadally smoothed with 13-year Gaussian filter.

It is difficult to contemplate how these particular sites could have survived the quality control procedures supposedly employed by O&B.

Figure 2 illustrates another ironic aspect to O&B proxy #1. The top panel shows the archived PC1 from Jones and Mann [2004] (used by O&B), while the next two panels show the PC1s as calculated using the two possible options of the covariance matrix and the correlation matrix. For networks already expressed in common units, standard references [Rencher 2002], Overland and Preisendorfer 1982] recommend the covariance matrix method, but Huybers [2005] argued for the correlation matrix. In both networks, the influence of Sheep Mountain is reduced and neither has a strong hockey stick. Early 20th century levels are as elevated as later.

Figure 2. PC1s for the AD200 North American network. Top — Jones and Mann [2004]; middle — covariance matrix; bottom — correlation matrix.

Proxy Selection
However, the most fundamental problem with studies of this type is their failure to define proxy selection procedures on an ex ante basis. If white spruce or larch ring widths for treeline sites are believed to be a valid temperature proxy, then these chronologies should be collected and collated and reported. Authors should not ex post check on their correlation to local temperature and cherry pick sites with a “favourable” response, while failing to report or de-selecting sites with a seemingly “unfavourable” response. Why are the 4 rejected Esper sites no good?

The reason for not relying on correlation-based tests for proxy selection is that it easily fools the eye. The stock market is notoriously hard to forecast. Stock-pickers long dreamed of finding reliable ways of forecasting the stock market by finding data series that are easy to forecast, but which reliably correlate to the stock market, therefore yielding a reliable forecasting tool. But whenever they select series based on correlation statistics, they turn out to have lousy out-of-sample forecast properties for the stock market. Econometricians realize that autocorrelated series frequently yield what are called “spurious regression” results. The same problem bedevils paleoclimatology. There are hundreds, if not thousands, of tree ring sites. Briffa [2000] has reported that the vast majority of these sites have failed to record increases after 1960, contrary to the hypothesis that there is a linear relationship between temperature and ring width.

In the O&B study, which builds on prior studies with similar selection procedures, from this large population in which ring widths and density (mostly) decline after 1960, a few sites are selected which nearly all have strong (and in some cases) very strong post-1960 growth: the bristlecones, Yamal, Sol Dav (Mongolia). The selections are hardly random. In determinations of statistical significance, the selection procedure needs to be modeled — an effect familiar to econometricians. [Ferson et al 2003].

While O&B purport to test for statistical significance using a Monte Carlo analysis, they fail to model the selection process. Their failure to do so makes their estimation of statistical significance totally worthless.

There are many other questions as to the validity of the O&B proxies. Their foxtail series (#3) — one of the key contributors to their exceedance statistics — is attributed to Lloyd and Graumlich [1997], who state, contrary to O&B, that:

[the period] 950 to 550 years BP [...was] a period of warm temperatures (relative to the present) in which at least two severe, multidecadal droughts occurred

Lloyd and Graumlich discuss declines in treeline during the past millennium. Evidence of this decline can be seen in this recent photo of a subfossil medieval tree in alpine tundra well above the present treeline. Whatever the cause of the changes in treeline may be, O&B have presented no evidence that the foxtail ring width chronology (which cannot be identified in the citation anyway) is a valid proxy for long-term temperature changes.

Figure 3 (Original Caption): A dead trunk above current treeline from a foxtail pine that lived about 1000 years ago near Bighorn Plateau in Sequoia National Park

Similar questions arise in respect to their Siberian proxies. O&B have selected the Yamal series, which has strong 20th century growth contributing markedly to their exceedance statistics. In contrast to the selective picking of sites employed in O&B, Naurzbaev et al. [2004] (which included MBH co-author Hughes) carried out a comprehensive study of 34 larch sites along a latitudinal transect and 22 larch sites along an altitudinal transect. They concluded:

Trees that lived at the upper (elevational) tree limit during the so-called Medieval Warm Epoch (from A.D. 900 to 1200) show annual and summer temperature warmer by 1.58 and 2.3 deg C, respectively, approximately one standard deviation of modern temperature. Note that these trees grew 150–200 m higher (1–1.28C cooler) than those at low elevation but the same latitude, implying that this may be an underestimate of the actual temperature difference.

That such different conclusions can seemingly arise from consideration of Siberian tree ring chronologies points to the need to avoid ex post selection criteria and the need to develop and consistently apply ex ante selection criteria.

Peer Review
Undoubtedly, more issues will arise with further study and, if and when the various data sets are archived. But some points on peer review are obvious.

First, it is clear that Science peer reviewers simply do not check any of the calculations in an article. Errors can arise in many ways without any fraud being involved and checking is always worthwhile. If Science peer reviewers are not going to check calculations themselves, then they (or Science editors) should ensure that authors comply with Science’s archiving obligations. Better yet, Science should adopt procedures that are best practices at economics journals, requiring authors to archive code as a pre-condition to publication.

In a recent publication in which both Briffa and Mann were coauthors (Rutherford et al. 2005), the authors have, to their credit, archived code for their calculations. Unfortunately for them, the code shows that they incorrectly collated the instrumental records into their calculations using MBH98 proxies, a simple error which unfortunately affects all their subsequent calculations in respect to MBH98 proxies incorrect (see ). However, such incidents should not discourage authors from archiving their code (NB: the code for this review will be archived (see

In the course of recently acting as a reviewer for the IPCC 4th Assessment Report, I asked the IPCC secretariat and the authors of certain proxy studies for data. The IPCC refused to provide this data to me on the grounds that the function of a reviewer was simply to ensure that IPCC properly recorded the findings as published in journals and not to carry out independent quality control or checking of papers relied upon by the IPCC — which they said was the province of the journals. Given that the journals are not discharging this function, the IPCC policy of denying data is simply breathtaking in its insouciance and a recipe for another fiasco like Mann et al [1998].

Esper, Jan, Edward R. Cook, Fritz H. Schweingruber, 2002, Low-Frequency Signals in Long Tree-Ring Chronologies for Reconstructing Past Temperature Variability, Science 295, 2250 — 2253.
Ferson, W., S. Sarkissian and T Simin, 2003. Spurious regressions in financial economics, Journal of Finance, 58(4), 1393-1413;
Graybill, D.A., and S.B. Idso. 1993. Detecting the aerial fertilization effect of atmospheric CO2 enrichment in tree-ring chronologies. Global Biogeochemical Cycles 7:81-95.
Grissino-Mayer, Henri D., 1996. A 2129 year annual reconstruction of precipitation for northwestern New Mexico, USA. In Dean, J.S., Meko, D.M., and Swetnam, T.W., eds., Tree Rings, Environment, and Humanity. Radiocarbon 1996, The University of Arizona, Tucson: 191-204.
Huybers, P. (2005), Comment on “Hockey sticks, principal components and spurious significance” by McIntyre and McKitrick, GRL, L20705, doi: 10.1029/2005 GL023395.
Jones, P. D., and M. E. Mann (2004), Climate over past millennia, Rev. Geophys., 42, RG2002, doi:10.1029/2003RG000143.
LaMarche, V.C., D.A. Graybill, H.C. Fritts, and M.R. Rose., 1984. Increasing atmospheric carbon dioxide: tree ring evidence for growth enhancement in natural vegetation. Science 225:1019-1021.
Lloyd, A and L. Graumlich, Ecology 78, 1199.
Mann, M.E., Jones, P.D., Global surface temperature over the past two millennia, Geophysical Research Letters, 30 (15), 1820, doi: 10.1029/2003GL017814, 2003.
Mann, M.E., R.S. Bradley and M.K. Hughes (1998), Global-scale temperature patterns and climate forcing over the past six centuries, Nature, 392, 779-787.
McIntyre, S. and R. McKitrick (2005b), The M&M Critique of the MBH98 Northern Hemisphere Climate Index: Update and Implications, Energy and Environment, 16, 69-99.
McIntyre, S. and R. McKitrick, (2005a), Hockey Sticks, Principal Components and Spurious Significance, GRL, 32, L03710, doi:10.1029/2004GL021750.
McIntyre, S., and R. McKitrick (2005c), Reply to comment by Huybers, GRL, 32, L20713, doi:10.1029/2005GL023586.
Naurzbaev, Mukhtar M., Malcolm K. Hughes, Eugene A. Vaganov, 2004. Tree-ring growth curves as sources of climatic information, Quaternary Research 62, 126– 133
Osborn, Timothy J. and Keith R. Briffa, 2006, The Spatial Extent of 20th-Century Warmth in the Context of the Past 1200 Years, Science 311, 831-834.
Rutherford, S., Mann, M.E., Osborn, T.J., Bradley, R.S., Briffa, K.R., Hughes, M.K., Jones, P.D., Proxy-based Northern Hemisphere Surface Temperature Reconstructions: Sensitivity to Methodology, Predictor Network, Target Season and Target Domain, Journal of Climate, 18, 2308-2329, 2005.
Soon, W. and Baliunas, S., 2003: Proxy climatic and environmental changes of the past 1000 years. Climate Research, 23, 89-110.
von Storch, H., and E. Zorita (2005), Comment on “‹Å“”‹Å“Hockey sticks, principal components, and spurious significance”. by S. McIntyre and R. McKitrick, Geophys. Res. Lett., 32, L20701, doi:10.1029/2005GL022753.
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  1. John A
    Posted Feb 9, 2006 at 1:40 PM | Permalink | Reply

    Does anyone else feel we’ve seen this exact same article before? I don’t know whether to be sad or angry.

  2. Steve McIntyre
    Posted Feb 9, 2006 at 2:00 PM | Permalink | Reply

    The R-script is archived at . There are some steps shown for reference that rely on other collated data; in such cases, the excerpted data has been separately archived. It only takes a little time to do this sort of housekeeping at the time of an article and one wishes one more time that O&B and the rest of the Hockey Team would archive their scripts. Let me know if there are any loose ends as I sometimes edit on the run.

  3. jae
    Posted Feb 9, 2006 at 2:22 PM | Permalink | Reply

    Alas, another paper to help establish “concensus.” The more citations, the more concensus, right?

  4. John A
    Posted Feb 9, 2006 at 2:53 PM | Permalink | Reply

    And like dutiful acolytes, the BBC Propaganda Team waste no time in spindoctoring the latest Hockey Stick just like the previous one:

    In the late 20th Century, the northern hemisphere experienced its most widespread warmth for 1,200 years, according to the journal Science.

    The findings support evidence pointing to unprecedented recent warming of the climate linked with human activity.

    A team from the University of East Anglia measured changes in tree rings, fossil shells and ice cores and other past temperature records or “proxies”.

    These people have no shame.

  5. Pat Frank
    Posted Feb 9, 2006 at 6:11 PM | Permalink | Reply

    So, Steve, can we gather that we’re reading a draft of your letter to the “Technical Comments” department of Science magazine?

    One would think that John Kennedy, already publicly wringing his hands over the failure of his peer review panel in the Hwang stem cell case, would be more than ready to rectify other faults brought to his attention regarding Science’s reviews procedure.

  6. john
    Posted Feb 9, 2006 at 6:40 PM | Permalink | Reply

    I have begun to take a look at the proxy data as a hobby interest (I have digital signal processing background and am approaching the data from this point of view). I have only investigated a few proxies, but so far the ones I have looked at are indistinguishable from Gaussian distributed noise. That is deeply disappointing. So far I am getting the feeling that the “Emperor has no clothes”. I don’t see how the current proxies I have looked at could be used for anything meaningful at all. Maybe I just stumbled on the bad ones so far. Maybe some of the other proxy data will be better. In another post I commented about extracting the MWP for local group of proxies (no one denies that the MWP did occur in some local areas do they?). This would be a good test. A result that turns noise into a flat line (except of course over the calibration region where it will line up by definition) is no result at all. First show that the technique works for regions where a known trend has occurred. Does anyone know if someone has done this? It seems obvious, it must have been done. To reiterate my test proposal here, if the hockey graph is correct then:
    - we should expect to see MWP occur for different areas at different times.
    - the sum of the different areas should cancel out to create our original file line.
    - The MWP periods for each region should roughly line up with external results

    Probably just a couple of bad proxies, probably I will regret posting this right after I look at the next one ;-)

  7. Suggestion Guy
    Posted Feb 9, 2006 at 6:55 PM | Permalink | Reply


    An interesting feature for the site might be a web page that contains a simple grid with the Hockey Team papers and their recurring issues.

    Each row label down the left would be the separate paper (MBH, O&B, etc), with the column headings across the top being the various recurring problems (e.g., proxy selection, QC, weighting, filtering issues, Bristlecones included, etc.).

    An “X” would be included in each appropriate cell where the recurring problem occurred for that paper.

    Those Xs would also link to your blog comment on the particular issue.

    A “comments column to the right would include short other comments that are linkable to your other blog entries on them.

    As an aside, I find your blog comments to be interesting and educational for non-climate scientists, such as myself, interested in the topic. Keep up the good work.

  8. Pat Frank
    Posted Feb 9, 2006 at 8:08 PM | Permalink | Reply

    #7 — John have you tried Fourier filtering the proxy data? If you make a Fourier transform (FT) the the proxy data, any underlying oscillations should emerge as low frequency peaks in the FT of the data. The high frequency components — the noise — can then be filtered out by back-transforming the FT spectrum using a Gaussian filter to extract the low-frequency peaks. If proxies have the MWP and the LIA in them, they should show up as a recurring periodic signal in the filtered, back-transformed proxy data.

    If they don’t, and in fact if the MWP and LIA show up in no back-transformed proxy data, then it would be fair to say that the signal of these events is not present. If that were the case, then the periodicities claimed to be in the combined proxy data sets by the IPCC and others would be hard to rationalize as anything except an artifactual outcome.

    That leads me again to something I’ve wondered about before here; namely it seems to me that the “noise” in proxy data is not noise at all but a combination of measurement error plus the local high-frequency variation in the data. That makes the high frequency components non-random, and one wouldn’t expect them to average out. Instead, you’d just get a plot with low-frequency components reflecting the non-zero sum of high-frequency non-random anomalies. Every proxy compilation plot would then just be an artifact of the choice of proxies to be summed up. The “convenience sampling” error would come into play here. Everyone uses the same non-random set of proxies and so their plots end up showing the same artifactual sums.

  9. john
    Posted Feb 9, 2006 at 9:12 PM | Permalink | Reply


    Yes, this was the approach that I took initially. Plot the spectrum and look to see what spectral components rise above the background noise level, then zero all of the other components, do the inverse transform and plot the result. I have had better luck with some of the other proxies I have looked at since my post. There is a small ‘signal’ in the lower frequencies, however the percentage contribution of background noise (based on comparing to what I believe the level would be without this signal) is extremely high and in some cases (such as the first proxies I looked at) either there is no trend, or the noise dominates. But there does seem to be something there at least in some of them. This is a much simpler (and robust) approach then the principal component approach. Personally I don’t see what the principal component approach is supposed to achieve unless one believes:
    - there are multiple linearly independent variables that contribute to the final proxy parameter (are temperature, precipitation, wind, cloud cover, etc. linearly independent?)
    - these independent variables vary in the same way (although potentially scaled or shifted) for each of the distributed proxy locations.

    Neither of these seems likely to be true to me. I don’t think anyone is actually seriously questioning whether they ‘should’ be using principal components, they just are — like kids with a fancy new toy.

    Other more boring straightforward techniques are more likely to produce a robust and believable result (i.e. if weighted averaging is good enough for land-based sensor data, it should be good enough for proxy temperature data values to).

  10. john
    Posted Feb 9, 2006 at 9:26 PM | Permalink | Reply

    #10 — actually the variables can be the linearly dependent, my point was I don’t believe the underlying variables are ‘linearly’ dependent. If they were, climate modeling would be a piece of cake.

  11. Larry Huldén
    Posted Feb 10, 2006 at 1:36 AM | Permalink | Reply

    … the function of a reviewer was simply to ensure that IPCC properly recorded the findings as published in journals and not to carry out independent quality control or checking of papers relied upon by the IPCC — which they said was the province of the journals. …

    With this statement IPCC agree that they are cherry picking journals and results in accordance with their beliews.

  12. Peter Hearnden
    Posted Feb 10, 2006 at 3:17 AM | Permalink | Reply

    Re #2, well, I simply don’t know how Steve produces so much so quick on his own. I think it’s amazing dedication.

    Re #5. ‘John’, you really need to try to understand what reporting means. I know you see propaganda everywhere, but ‘to report’ is simply that. But, perhaps in ‘John A ‘ world you’d censor the BBC and only allow climate to be reported on by yourself and Steve? Yes, I think that’s what you’d do.

  13. Posted Feb 10, 2006 at 3:33 AM | Permalink | Reply

    Hi Steve
    Quite a different discussion to O+B compared to RealClimate.

    I just want to make a quickish comment with regards to ‘cherry picking’ of data that you have an issue with. I think you’re being too idealistic.

    In 1998, I sampled 21 tree-ring chronologies at/near tree-line in Interior British Columbia. The aim of the study was to develop a regional summer temperature reconstruction for the region. Despite trying to target “ideal” sites through the region, it simply was not possible to sample consistent ecological/elevational situations. The result of these site differences was that the climate response of the trees from different sites varied. This is particularly true for ring-width data, although less so for density data.

    I had two choices – “cherry pick” those sites with the strongest signal, or use a method like principal component regression to use the dominate variance modes in the data. In fact, I used both methods, resulting in very similar results. The “cherry picking” approach being only superior as I was able to generate a longer reconstruction.

    For those interested, the study is published:

    Wilson, R.J.S. and Luckman, B.H. 2003. Dendroclimatic Reconstruction of Maximum Summer Temperatures from Upper Tree-Line Sites in Interior British Columbia. The Holocene. 13(6): 853-863.

    However, it is the latter point about LENGTH that is crucial for understanding climate of the last 1000 years. From my BC study, I did not manage to sample ONE site > 500 years.

    There are thousands of TR chronologies in the ITRDB, but how many of them have both an acceptable signal strength (i.e. high replication) back 1000 years and a clear response with temperature. NOT MANY!

    This is the simple reason why all the NH reconstructions to date use similar data-sets – there are no others and acquiring new data-sets take time and luck.

    In our recent paper (eclipsed by O+B, I am afraid)

    D’Arrigo, R., Wilson, R. and Jacoby, G. 2006. On the long-term context for late 20th century warming. Journal of Geophysical Research, Vol. 111, D03103, doi:10.1029/2005JD006352,

    note our cautionary statement about there being simply NOT enough data to make definitive conclusions about the MWP compared to the recent period – at least when reconstructing NH annual temperatures. The MWP was simply spatially more complex than the recent period. More data are needed.


  14. David H
    Posted Feb 10, 2006 at 3:50 AM | Permalink | Reply

    Peter, even you must agree that climate change in general and the Hockey Stick in particular is just a teeny bit controversial. Usually the BBC makes some attempt at balance. Think about MMR the Iraq war, ID cards. With AGW, I get the feeling that CRU, DEFRA and IPCC press releases go straight into the bulletins.

    That they have not as yet reported the NAS committee shows that they can not be researching the topic at all.

  15. Peter Hearnden
    Posted Feb 10, 2006 at 4:09 AM | Permalink | Reply

    Re #15. Sure, the recons aren’t perfect – no one claims they are – but it’s pretty clear recent warmth is anomalous. But to suggest the beeb is in on a big conspiracy? Nope, it REPORTED the paper. You think it should have suppressed it? I don’t.

    DO I think I should report the upcoming NAS bunfight? Humm, I suspect they will, though it is a bit obscure as yet surely? I rekon they might wait for the conclusions. I mean, they didn’t report O&B when that was work in process did they.

  16. Posted Feb 10, 2006 at 4:24 AM | Permalink | Reply

    Hi, thanks for the article, haven’t finished reading yet but it’s interesting (and disappointing).

    I tried to go to the URL you provided,, and got this error:


    You don’t have permission to access /data/osborn06/ on this server.
    Apache Server at Port 80

  17. David H
    Posted Feb 10, 2006 at 5:20 AM | Permalink | Reply

    Peter, a tiny fraction of peer reviewed papers get top billing in news reports. Why are so many the AGW scares? I do not think there is a conspiracy at the Beeb. They are just lazy and headline seeking. I think very little should be suppressed and certainly not the data that these scares are derived from or the criticisms of them.

    The programme they put out last night on Dark Matter was much better and showed the realities of research. Uncertainties and contradictions and upsets.

  18. Brooks Hurd
    Posted Feb 10, 2006 at 6:50 AM | Permalink | Reply

    The BBC article stated that

    The researchers used proxy data developed from the diaries of people living in the Netherlands and Belgium during the past 750 years

    Note that this time frame begins in the middle of the LIA, something the BBC failed to recognize. No one is arguing that there has not been warming over the past 750 years. These diary excerpts do not support O & B’s conclusion (perhaps premise) that

    “The last 100 years is more striking than either [the Medieval Warm Period or Little Ice Age]. It is a period of widespread warmth affecting nearly all the records that we analysed from the same time,” co-author Timothy Osborn told the BBC.

    The BBC is typically balanced in their science articles, except when the topic is AGW. I have emailed the reporters pointing out that there were other scientists who could have provided balance to their articles. The typical reply claimed that the “scientific consensus” did not require them to provide any balance. It is difficult to engage in a scientific argument with a Hockey Team cheerleader.

  19. Peter Hearnden
    Posted Feb 10, 2006 at 7:26 AM | Permalink | Reply

    Brooks, I wish you had some we COULD argue about – like a sceptic recon, or some new research Steve has done. But, it’s all criticms of other work here, ALL OF IT, EVERY DAMN WORD!

    Of course, I’m now about to find out how difficult it is to engage with one of Steve’s pack. I expect a patronising reply, asking me to ‘engage’ or ‘read’ or ‘stop the personnal stuff’ or similar…

  20. fFreddy
    Posted Feb 10, 2006 at 7:27 AM | Permalink | Reply

    Re #18, David H

    The programme they put out last night on Dark Matter was much better and showed the realities of research.

    Particularly the guy being rude about using huge computers to model the evolution of the universe and calling it proof of the underlying assumptions – I’d definitely like the Beeb to show the same sort of view of GCMs.

  21. Louis Hissink
    Posted Feb 10, 2006 at 7:34 AM | Permalink | Reply

    Re #20


    Steve has no resources to do new research, as no one is funding him. Your point is rejected.

    Sensitive to criticism? The only individuals sensititive to scientifically based criticism are charlatans, or dodgy mining entrepreneurs, in my experience.

    What’s yours?

  22. Paul Linsay
    Posted Feb 10, 2006 at 8:00 AM | Permalink | Reply

    There’s an interesting review of O+B at Junk Science. He points out that if you take their results at face value, the 1990′s are cooler than the 1930′s and 1950′s. Temperatures still haven’t rebounded from the cooling that was going on around 1970.

    This is consistent with the reconstruction of the US temperature record by Hansen et. al. before they do their magic “corrections.”

    #14, Rob: I’ve never understood how tree rings can be used as a temperature proxy for a variety of reasons. First, ring width is due to multiple variables, temperature, water, sunlight, CO2, soil fertility… Without a handle on all those variables how can you extract the response to temperature? Second, the nonlinear response of growth to each variable. Too much or too little stunts growth, there’s an optimum intermediate amount of each variable. Are there studies of tree biology that allow you to control for all of this?

  23. fFreddy
    Posted Feb 10, 2006 at 8:02 AM | Permalink | Reply

    Re #20, Peter Hearnden

    I expect a patronising reply, asking me to “engage’ or “read’ or ‘stop the personnal stuff’ or similar

    What, like “There’s only one ‘n’ in ‘personal’, Peter” or some such ?

  24. Peter Hearnden
    Posted Feb 10, 2006 at 8:06 AM | Permalink | Reply

    Re#24, yeah, probbably…

  25. fFreddy
    Posted Feb 10, 2006 at 8:31 AM | Permalink | Reply

    Heh, well done.
    Seriously, Peter, this business of “Steve M doesn’t make reconstructions, he only criticises others, therefore he should be ignored” ill-becomes you.
    While you and I disagree on the subject of AGW, your position seems to be an honest one: you don’t seem to be either someone whose budget is improved by climate alarmism, or someone who has some basic anti-capitalist axe to grind.
    We know that professional climatochappies like Dano never check what they read in the journals, because they don’t have time. We know that leading magazines like Science publish bogus papers because that Hwang chap has just been caught out.
    Surely you can agree that checking other people’s work is a entirely valid part of the scientific process ?

  26. MichaelS
    Posted Feb 10, 2006 at 8:35 AM | Permalink | Reply

    David H makes the point that the Beeb reports other “unpopular” stories, such as the war in Iraq et. However all the anti government stories that the Beeb reports are essentially a critique from the left or at least from a prediced view (War in Iraq – against, Climate Change – for etc).

    On GWCM the Beeb is definitely biased.

    They report stories in Science in Nature that support the Hockey stick, but there was no mention in the Beeb of von Stoch (Science 2004) and Moberg (Nature 2005) that critiqued the hockey stick methodology.

    This is exactly their dishonesty when they say the science is “settled”. Hockey stick science is not settled and if they report an article for they hockey stick, they should certainly report articles in the SAME Journal (or like peer reviewed journals) against.

    Here is my challenge to you: If you get a peer reviewed article that critiques the hockey stick accepted by a decent journal, let the Beeb know (and let the Today program in the morning know). I will lay odds that the Beeb will not report it.

  27. Peter Hearnden
    Posted Feb 10, 2006 at 8:50 AM | Permalink | Reply

    “We know that professional climatochappies like Dano never check what they read in the journals, because they don’t have time. We know that leading magazines like Science publish bogus papers because that Hwang chap has just been caught out.”

    And such comments ill become you. You no more know that than I know ‘John A’ is a professional sceptic (I don’t).We know leading science magazines aren’t perfect (hell, even Steve makes mistakes) but to try and prove the whole barrel because of one apple (OK, since you’ll present another, two then)? Tendentious is the word I think.

  28. Louis Hissink
    Posted Feb 10, 2006 at 9:36 AM | Permalink | Reply


    Do you actually understand what Steve and Ross are pointing to?

  29. jae
    Posted Feb 10, 2006 at 9:37 AM | Permalink | Reply

    Peter Hearnden
    Apostle, Venerable Church of AGW and Impending Doom

    Re #24, here it is:

    Posts like #20, 26, suggest to me that you have a very closed mind and just do not understand most of the people on this blog. Many, and especially Steve, have not taken any public stance on whether AGW is a reality. They simply question some of the studies that are being used to support it. That is the essence of science. You do not have to analyze tree rings and construct a hockey stick graph to be a scientist or to contribute to the literature. Review of papers is critical in science (Steve’s work is showing that it is particularly critical, relative to the Hockey Stick spagetti). It appears to me that you strongly BELIEVE that AGW has definitely been proven and that there is simply no need to question ANYTHING that supports the theory, especially if the people doing the questioning have not been knighted as climatologists.

  30. Paal
    Posted Feb 10, 2006 at 9:44 AM | Permalink | Reply

    Interesting that there are noe references to the McIntyre, S. and R. McKitrick papers in the Science Paper. Should we guess whos the referees??

  31. Spence_UK
    Posted Feb 10, 2006 at 9:46 AM | Permalink | Reply

    I haven’t had a chance to review the paper yet, but when reading through the various reports, this reminded me of a paper highlighted by Demetris Koutsoyannis (see here) and discussed later in the comments of that thread:

    In this, Hans von Storch warns against an obvious problem: or rather, a problem he states as obvious, a trap into which climate scientists should not fall into, but there seems to be evidence that they do. The section of interest is section 2.2, “Mandatory Testing and the Mexican Hat”. I actually don’t think the Mexican hat is the best analogy for a number of reasons, but the subsequent discussion is very much applicable.

    The problem with having limited data, and using an even more limited subset of that data, is that we go trawling through data looking for a relationship. We know the data sets we are operating well (because the data sets are small and limited), which means we tend to automatically select data that supports our argument. We can then subsequently cut that data into two separate sets (as von Storch suggests), but in the initial data selection step, the potential for spurious relationships is already there. The verification period becomes part of the calibration. This is termed subconcious data selection, and is a very easy trap to fall into.

    Essentially, by trawling data with a loose specification of what you are looking for, then subsequently reporting as if you were looking for something with a tighter specification (based about what you actually found) is a trivial way of generating highly significant spurious relationships. The infamous “bible codes/torah codes” debate is a great example of this. And I suspect O&B’s “proof” of recent warming is little better than finding a prediction of it in the bible (or moby dick, for that matter).

    Von Storch’s observations are that the safest bet is to monitor what happens subsequently, to validate the hypothesis. With time series, this is entirely possible. Unfortunately this validation step never seems to happen as climatologists want to “move on” every time a paper gets to be a few years old.

  32. John A
    Posted Feb 10, 2006 at 9:59 AM | Permalink | Reply

    Peter “the well-poisoner” Hearnden writes:

    We know leading science magazines aren’t perfect (hell, even Steve makes mistakes) but to try and prove the whole barrel because of one apple (OK, since you’ll present another, two then)? Tendentious is the word I think.

    “We know leading science magazines make mistakes” makes it sound like a schoolboy error involving vulgar fractions rather than a criticism of the reason they exist. The case of Hwang Woo Suk is the latest in a long line of scientific fraudster who were not caught by the peer-reviewers themselves but by people auditing and checking published data.

    In the Hearnden bizarro world, such people should not be allowed to criticize Hwang Woo Suk unless they had cloned their own dog, or run a genetics laboratory.

    You go then on to say “Well even Steve makes mistakes” as if that means anything. Steve isn’t publishing a science magazine and representing it to be verified. Steve welcomes proper thorough checking of all his work by anyone. You have not identified a bona fide mistake in any of Steve’s published articles, but you have played as close to the line as you can of accusing him of doing so.

    Excuses like “everyone makes mistakes” are not acceptable if that is the sole purpose of your occupation. There are clear systemic failures in the peer-review of many scientific articles that cannot be excused with “we’re not perfect but then who is?”. Is that going to be the excuse for spending trillions of dollars in a vain attempt to modify climate? Everyone makes mistakes?

    I note earlier you ranted about me wanting to censor the BBC – but I have never advocated that. Quite the reverse, I advocate that the BBC get off its lazy journalistic backside and start investigating stories rather than copy/paste from press releases as they clearly have done. I would demand that they stop suppressing an increasing number of properly done studies which do not confirm the AGW hypothesis and start asking critical questions of everybody.

    This blog is almost exactly a year old. We’re still waiting for Peter Hearnden to make a substantive statement of fact.

  33. Louis Hissink
    Posted Feb 10, 2006 at 10:24 AM | Permalink | Reply

    Hear Hear

  34. beng
    Posted Feb 10, 2006 at 11:20 AM | Permalink | Reply

    Steve_M, this topic seems to encapsulate the major HS issues — even a nice pic.

  35. Steve McIntyre
    Posted Feb 10, 2006 at 11:31 AM | Permalink | Reply

    #32. Spence, I agree entirely. I’ve speculated for some time that Hughes’ 2002 studies at Sheep Mountain did not produce ring widths that were over the moon or we’d have heard about them. I’m suspicious of the delay in hearing anything about Thompson’s Puruograngri ice cores (2000!).

  36. J. Sperry
    Posted Feb 10, 2006 at 11:33 AM | Permalink | Reply

    Re #23 (Paul L.):

    I’ve never understood how tree rings can be used as a temperature proxy for a variety of reasons. First, ring width is due to multiple variables, temperature, water, sunlight, CO2, soil fertility… Without a handle on all those variables how can you extract the response to temperature?

    This comment in another recent post led me to Mann’s 2003 testimony, in which he answer your question (see Question 13). Mann typically berates the question (unjustly, in my opinion) before answering, and this is one of the more extraordinary examples. He actually makes a distinction between “remove the effects”, which he strongly feels “would be a most unwise approach”, and “separate the information”, which is what his methods do.

  37. Posted Feb 10, 2006 at 11:52 AM | Permalink | Reply

    #37 all he says is he uses “…multivariate statistical methods…to separate the information in the data…”. Call me a dummy but that’s just gobbletigook to me. On the other hand, M&M are statisticians so they should be able to understand that question. Can Mr. McIntyre or Mr. McKitrick enlighten us about how these statistical approaches are able to seperate out the various parts of the signal which are stored in the proxies? Are they merely looking for correlation between them, and saying that is sufficient enough to assume that the correlation which is being found must be for only one of these variables, or is it something more sophisticated?

  38. Peter Hearnden
    Posted Feb 10, 2006 at 12:19 PM | Permalink | Reply

    Re #29, Louis, I know how smart you are.

    Re #30, got your insult in early I see.

    You seem confused. YOu say, rightly, Steve takes no strong AGW position, then you, absurdly, claim he is meerly ‘questioning’ studies. Where have you been? Obviously not here…

    You then claim I ‘believe’ in AGW unquestioningly. I do not, I think it very likely – I can’t see how some AGW might not exist. Do you rule out that? Questions are fine, rubbishing gets people back up. If you’d done some back up you’d know I don’t think the extreme of either warming or no warming likely.

    Re #33. A typically disconnected from reality and downright insulting post. I’ll comment on it no more.

  39. Steve McIntyre
    Posted Feb 10, 2006 at 12:40 PM | Permalink | Reply

    Peter, can you point to any incorrect comments that I’ve made about climate issues? I agree that some comments are very critical of some prominent people. However, if the comments are correct, then they are responsible for the “rubbish”, not me.

  40. jae
    Posted Feb 10, 2006 at 12:52 PM | Permalink | Reply


    then you, absurdly, claim he is meerly “questioning’ studies. Where have you been? Obviously not here…


  41. Peter Hearnden
    Posted Feb 10, 2006 at 12:59 PM | Permalink | Reply

    Steve, I don’t think your position dishonest or insincere, nor do I think you ‘in the pay’. I do think that your one man attempt (you don’t have help – right?) to re-write the climate of the last 1000 years (and other matters you touch on) a big task. I’m not convinced you are right in all your claims, by any means. I think you wrong in many – so you probably have, imo, made some incorrect comments. No offence meant, just my view. As I’ve said many times (pick up and run with this ‘John A’ if you like, I’m just being honest) I’m no expert. I think the experts are broadly right*, other think you are the expert and they wrong. OK, but I don’t think that. Now, bring the house down on me for my temerity.

    You say you are very critical of some people. Yup, that’s about it.

    * that at present it’s as warm now as for 1000 and probably 2000 years.

  42. Dave Dardinger
    Posted Feb 10, 2006 at 1:38 PM | Permalink | Reply

    Since Peter won’t understand jae’s “Huh?” let me explain. Apparently Peter has a political rather than a scientific worldview. That is, if someone criticizes the work of a person with position A, then ipso facto the critic is opposed to position A.

    What he doesn’t realize is that, in science, criticism is designed to improve the work of others, not necessarily to oppose the position on a given subject held by a person. If the person who receives scientific criticism modifies his work to eliminate any problem found, this may or may not have a material effect on a position.

  43. Paul Linsay
    Posted Feb 10, 2006 at 1:55 PM | Permalink | Reply

    #37, J. Sperry. Thanks for the reference, I’d never seen it before. It’s pure BS. There’s only one equation and five unknowns and no way on earth that “multivariate statistical methods” can do the trick without four more equations. Notice how he avoids directly answering the question of error. I don’t have access to the journal articles but I’d be surprised if the problems of reconstrucing sea surface temperture are the same as extracting temperature from tree rings.

  44. ET SidViscous
    Posted Feb 10, 2006 at 1:56 PM | Permalink | Reply

    More importantly he is misunderstanding the issue when he (Peter) says:

    “I do think that your one man attempt (you don’t have help – right?) to re-write the climate of the last 1000 years”

    Steve is definitely not doing that, it is Mann et al that are doing that, in fact Steve is taking “Peter’s position” of Mann et-als attempt to re-write climate history. Before the Hockey stick the Medieval Warm period and Little Ice age were accepted events, hence the fact that they have names, and these names existed before the Hockey stick. I.e. before the Hockey team it was generally accepted within paleoclimatolgy circles that there was a warm period called the MWP, and following that a Little Ice age (LIA). Mann et al then tried to reduce the magnitude of those events with their work. In other words Mann et-al are attempting to re-write the climate of the past 1000 years.

    They may be right (I tend to disagree in large part because of Steve’s work). But if they want to come up with an alternate to the previously generally accepted view, they need to have strong ground to stand on, hence the need to review their data and methods.

  45. John A
    Posted Feb 10, 2006 at 2:44 PM | Permalink | Reply

    Meanwhile, on Realclimate, after the traditional write-up of O&B by Michael “Hockey Stick” Mann himself which was spun up to 20,00 rpm, the comments so far have been, um, skeptical?

    Other than cheerleading from Fleck, Bloom and Dano, the questions have been about methodology, independence of the study from the original Hockey Team, statistical correlation and proxy selection.

    This isn’t going to plan for the Hockey Team.

  46. John S
    Posted Feb 10, 2006 at 2:57 PM | Permalink | Reply

    Re #38
    You are basically right – they are at heart just looking for correlation.
    They can’t separate all the forces out unless they specifically include precipitation or similar variables in their model. Consequently they are prey to ‘omitted variables bias’ (among other pathologies). Indeed their use of the term ‘multivariate’ (i.e. many variables) is stretching the truth. Their method hinges on univariate (i.e. one variable) regressions and thus all they are doing is actually finding correlations between their proxies and ‘global’ temperature. And, as we all know, correlation does not prove causation (especially when you have trending variables – which they do).

  47. Peter Hearnden
    Posted Feb 10, 2006 at 3:08 PM | Permalink | Reply

    Re #44, Dave, I think you make some points.

    Of course I have a political view, you don’t? You think yours isn’t part of you? But, and you only have my word, I do try to be objective.

    I must say I dont get the feeling anyone here is only criticising but in reality agrees with those they criticse. But, if you ‘John A’ Louis, ETSV, Spence_uk and the rest think AGW in the 2-4C range is remotely likely I have a range of hats I can eat ;)

    Et, But, can’t you see I can, from my pov, just reply with the same post and reversed roles? Thus, from my pov, Steve is trying to re-write…, increase the magnitude of…, he may be right… (I tend to disagree becuase of the work of ‘the team’…) etc etc. Now, before you reply, just think how the reply I sent feels, becuase that’s how your reply feels to me. We ALL think we’re right, it’s the resolving that matters. IMV, it wont be done until either your ‘side’ comes up with it’s recon that my ‘side’ can test (fat chance…) or my ‘side’ come up with other recons you can’t be bothered to try an pick holes in and/or a continued warming makes it obvious whats happening (much more likely). Of course you all think the present recons are broke, but you’re yet to convince more than yourselves and a few friendly politicians.

  48. ET SidViscous
    Posted Feb 10, 2006 at 3:22 PM | Permalink | Reply

    You still don’t get it Peter.

    Before Mann et-al the “consensus” was that the WMP was much warmer than now, and the LIA cooler. Mann et-all say that the MWP and the LIA are roughly equal (Straight shaft of the stick).

    Therefore they are re-writing. You cannot just reply in kind because the MWP and LIA paradigm came BEFORE, therefore Mann et-al are the one re-writing previous work.

    Either way Steve is not re-writing anything, he is simply examining Mann’s work. If Mann’s work fails previous climate could be colder, warmer, higher, lower or a Purple tele-tubby, but Steve is not saying anything about what it was, he is commenting only on Mann’s work.

    But as you’ve shown, you have no interest in rational arguments so yes you could re-iterate the same, but you would be wrong. You can disprove this by showing Steve’s climate reconstruction. It would be interesting to see since so many people have asked for it, and Steve says he hasn’t done such a thing. Therefore how could he be re-writing any paleoclimate. He is only commenting on the veracity of Mann’s work, not offering a substitute.

  49. Steve McIntyre
    Posted Feb 10, 2006 at 4:47 PM | Permalink | Reply

    Peter, if someone is doing an offering of securities, their financial statements have to be audited (and many other things). Auditors and securities lawyers mostly just check things. If an auditor finds problems with a company’s financial statements, no one tells the auditor – well, why don’t you start up your own business? or why don’t you do the statements? The responsibility for the accounts belongs to the corporation. Why should we be developing public policy on the equivalent of unaudited statements?

    Obviously I don’t have any official standing as an auditor of climate studies, but, unlike corporate accounts, scientific results are supposed to be replicable based on the disclosure of data and methods. At this point, other than a few realclimate diehards, I think most people would agree that if I can’t replicate a multiproxy study on the given record, then the problem probably lies with the record for the article rather than with me.

  50. jae
    Posted Feb 10, 2006 at 4:56 PM | Permalink | Reply


    I agree that one of the biggest problems in these studies is that there is no acceptable model for proxy selection. As I understand it, one of the prerequisites for using statistical tools is a random selection of the data. I am amazed that these guys can cherry pick proxies and then apply statistical methods–with a straight face! In my mind, this problem, alone, casts a very dark shadow on the results. I imagine you will mention this problem in your upcoming presentation.

  51. David Stockwell
    Posted Feb 10, 2006 at 6:02 PM | Permalink | Reply

    One good part of the O&B study are that it performs Monte Carlo exclusion of studies to show robustness. I think the comparison with MBH98 would be much less robust. With this more robust approach we do get a LIA and MWP, unlike MBH98, and this can only be good. The question is ‘how high?’ and here it shows desperation. The variance seems to be growing in stature with every episode – Esper, Moburg, O&B – looming over us. Would it be so bad for it to be warmer then than now? I wonder what would happen to GCMs if they were calibrated on recent dendro reconstructions, rather than instrument data. I haven’t seen anything like that.

  52. Dave Dardinger
    Posted Feb 10, 2006 at 7:49 PM | Permalink | Reply

    Yes, I have a political view, Peter. But I approach scientific studies from a scientific viewpoint. And that viewpoint is that you are skeptical of new ideas until they’re carefully demonstrated to be correct. In this particular area being skeptical of the science behind the AGW push happens to parallel my view of what the political views are of the people supporting it, but when the shoe is on the other foot I’m quite willing to question what someone with whom I agree politically has to say. Indeed I’ve done so several times in the forum I have tended to do most of my climate debating in and I’ve done it once or twice here too. But the reason you’re frustrating is that you never present any complaints about Steve’s work which can be debated. In your case you’ve excused yourself as not being sufficiently scientifically savvey.

    In the case of many others of the M&M skeptics they have the training but refuse to put it to use. And that makes them worse than you. Steve has presented hundreds of posts, many of them quite scientifically complex. But there haven’t really been any attempts by the hockey team to argue against any of his points. They only use misdirection (as you do in asking why Steve won’t present his own reconstruction) or resort to direct or indirect ad hominim attack.

  53. Posted Feb 10, 2006 at 8:38 PM | Permalink | Reply

    This site (new to me) includes some great thinking about dangers of scientists manipulating tech data to reach predetermined political conclusions. Poor tech reporting and MSM political bias impede efforts at fact checking, and objective peer review of studies. That said, the commentary section of your site is illuminating, except for the occasional non-tech nimcompoops who interject inane psychobabble into otherwise purely technical discourse. These nitwits don’t reserve a response, which only encourages more trivial, stupid worthless rebuttal, thus detracting from sensible technical problem solving.

  54. john
    Posted Feb 10, 2006 at 9:00 PM | Permalink | Reply

    I read this post on realclimate, and almost choked on my tea:
    My understanding is that the MBH99 estimate of non-climate related effects for the B_cone pines increased towards the end of the 19th century, then decreased in the 20th century. This would seem to be inconsistent with the known path of increasing CO2 concentrations in the atmosphere through both the 19th and 20th century, and the associated CO2-fertilization effect on vegetative growth.

    [Response: Actually, not. It is well understood by those who study terrestrial ecosystem dynamics that there are multiple limiting factors on growth. For example, once a tree has essentially as much CO2 as it can use, other conditions such as soil nitrogen availability, will become limiting. In addition, the longer the stomates remain open (to try to take in the additional CO2), the more vulnerable the tree becomes to water loss through evapotranspiration. So one would only expect a significant impact of Co2 fertilization only until these other limiting factors kick in. Any subsequent increase in ambient CO2 concentrations would have little incremental value to the tree once this happens. A plateau in the observed response is the rule, not the exception. There is a vast scientific literature on this sort of stuff. We'll leave it at that. - mike]

    Really!! We just ‘happen’ to be right below the transition point, and of course this applies universally regardless of tree type, location, soil type, etc., etc.

    Where to begin… Anyways, I think I see the fundamental difference between the two sides now. One group of people believes the climate is in an extremely delicately balanced system and that any infinitesimal perturbation to the parameters of the system will send the climate careening out of control, while the other group believes that the Earth’s climate is robust and will continue to cycle back and forth between ice ages as it has done for millions of years regardless of the minor perturbations of mankind. Interesting.

  55. john
    Posted Feb 10, 2006 at 9:08 PM | Permalink | Reply

    #55 This report would seem to disagree with Mr. Mann’s theory — Of course because it is from ‘sceptic’ site it should be ignored.

  56. ET SidViscous
    Posted Feb 10, 2006 at 9:09 PM | Permalink | Reply

    Where to begin? Easy.

    Assuming Mike is right it’s irrelevant. Because while there is vast scientific literature on this, the literature also states that CO2 concentrations today, and in the past 1000 or 1200 is nowhere near saturation, and that concentrations even 3 times higher than now has enormous benefits for plant growth.

    So while “For example, once a tree has essentially as much CO2 as it can use, other conditions such as soil nitrogen availability, will become limiting.” may very well be true, since the tree will never get “as much CO2 as it can use” at current levels, we are not seeing that limiting factor. So in fact Mike shows us that it is very likely that the Bristlecone series has been effected in the 20th century by CO2 fertilization and will continue to do so for centuries to come.

  57. john
    Posted Feb 10, 2006 at 9:18 PM | Permalink | Reply

    #57 But that is exactly my point. We are far far away from saturation and therefore his corrections to his data, which assume we have passed the saturation point, are incorrect.

  58. Steve McIntyre
    Posted Feb 10, 2006 at 9:21 PM | Permalink | Reply

    What Mann did in his CO2 “adjustment” in MBH1999 was the exact opposite of what Graybill and Idso called for – I’ll plot up his adjustment factor later. Lamarche, Fritts, Graybill and Rose 1984 for Sheep Mountain and Graybill and Idso 1993 for a wider selection of bristlecone and foxtail sites argued that early 20th century bristlecone growth was temperature related, but that the later pulse could not be accounted for by temperature or any cliamtic factors.

    Here’s Mann’s “Adjustment” – he adjusted the PC1 DOWN in the 19th century and slightly UP in the 20th century. There is some veiled language in MBH99 to cover his tracks, but the concept is bizarre – that CO2 improved 19th century growth, but saturation was reached in the early 20th century.

    But even if this were so, our point is that 20th century bristlecone growth is not related to temperature. In our E&E article, we raised other possibilities: phosphate fertilization, nitrate fertilization – for both of which there is some evidence and bristlecones on dolomite substrate are in VERY nutrient depleted soil.

    I’ve not seen any technical refrences to support the idea that CO2 saturation was reached circa 1900. Mann’s failure to provide a reference for this absurd concept is because there is none.

  59. Dave Dardinger
    Posted Feb 10, 2006 at 9:45 PM | Permalink | Reply

    re: #55

    Actually the most ignorant part of that reply is: “In addition, the longer the stomates remain open (to try to take in the additional CO2)…” The whole point is that with a higher concentration of CO2 the stomates don’t have to remain open as long, which allows the plant to utilize whatever water is available more efficiently. OTOH, if water is not a limiting factor, it doesn’t much matter how long the stomates are open. Finally if it’s another factor, like nitrogen which is limiting, it’s a moot point.

    Of course, Steve and others have pointed out here that part of the reason for the 20 century growth spurt by BCs is that there may have been dust-borne inorganic fertilization.

  60. Mike Carney
    Posted Feb 10, 2006 at 9:57 PM | Permalink | Reply

    # 42

    I think the experts are broadly right*, other think you are the expert and they wrong.

    How can you trust experts that refuse to make public their data and processes?

  61. Pat Frank
    Posted Feb 10, 2006 at 10:02 PM | Permalink | Reply

    #14 — Just out of curiosity, Rob, your JGR 2006 proxy reconstruction paper didn’t reference any of the M&M papers, even though your work compares reconstruction methods and your conclusion cautions about hazards due to tree-ring vs. Temp non-correspondences. Why did you leave out reference to M&M?

    M&M are not refrenced in Osborn and Briffa’s new work either. It’s looking like Ross’ and Steve’s work is being systematically shut out. Were you unaware of their work?

    On a related topic, did BBC or anyone else call to interview you about your results? Did you put out a press release? And why do you think your work, which looks more carefully done and more comprehensive than O&B, was ignored by the press?

  62. Steve McIntyre
    Posted Feb 10, 2006 at 10:37 PM | Permalink | Reply

    Pat, Rob is decent, but is unfortunately down the food chain (otherwise things would be different). Look at who’s down the masthead: D’Arrigo and Jacoby call the shots; that’s why the data isn’t archived and why we aren’t cited. An even more ridiculous example was in Esper, Wilson et al [QSR 2005] where Esper cited Regalado [2005] the Wall Street Journal article rather than citing us. That’s a little too ridiculous. I think that Rob should have argued a little in that case.

    As to press, Science manages the press to create a buzz. For example, they circulated the O&B paper under embargo for a few days. So the science reporters all think that it’s a big deal. But Science is sure going to cash in its chips if it’s hyping goofy articles like O&B as hot new stuff, when they are old re-treads. JGR doesn’t do stuff like that.

    Rob’s article is much better than O&B and Rob’s as likely as anyone to salvage something from tree rings.

  63. Steve McIntyre
    Posted Feb 10, 2006 at 10:57 PM | Permalink | Reply

    #55. Dave, I see that Mann has admitted that his answer got the stomata backwards “in his haste”. However, that then means that he didn’t answer the original question.

    Also, Mann points out that saturation is a nonlinear effect in ecology. Quite so. But, uh, Mike, didcha ever think about the possibility that this might apply to temperature? I’ll post on this on Sunday. Soon we’ll be able to nominate Mann for the Rasmus Prize in Botany.

  64. Steve McIntyre
    Posted Feb 10, 2006 at 11:41 PM | Permalink | Reply

    For the current discussion on CO2 and bristlecones, this past post is highly relevant

  65. ET SidViscous
    Posted Feb 10, 2006 at 11:46 PM | Permalink | Reply

    I’ve got to say. Isn’t this whole tree growth is affected by things other than temperature a bit bleeding obvious.

    But what do I know, I’m wacky enough to think solar output has something to do with global temperatures.

  66. nanny_govt_sucks
    Posted Feb 11, 2006 at 12:02 AM | Permalink | Reply

    #55: My follow-up question was “What evidence is there than any of the other growth limiting factors [for the bristlecones] have been reached?”

    It was, of course, censored.

  67. Steve McIntyre
    Posted Feb 11, 2006 at 12:21 AM | Permalink | Reply

    They are so despicable in their censoring. No wonder they’re afraid to engage in forums where they can’t retreat into censorship.

  68. Posted Feb 11, 2006 at 2:06 AM | Permalink | Reply

    Yes, those forums where they retreat into censorship are despicable.

  69. Posted Feb 11, 2006 at 3:11 AM | Permalink | Reply

    Although a passionate dendrochronologist, I cannot deny that there are issues that need to be resolved in dendroclimatology. However, the reality is that for the reconstruction of climate for the last 1000 years or so, tree-ring data will dominate.
    One of my personal frustrations of our JGR paper is that we did not (and could not) address the post mid 1980s calibration problems (i.e. that the TR data fail to model recent warming.)
    Such calibration issues have been documented in the literature and discussed at this site. This issue cannot be addressed in studies that try to reconstruct large scale climate, and can only be explored at the local level. We (the dendro community) are still at a stage where we are identify the problem and exploring reasons. We are not yet, I think, able to correct for these problems. If it is purely related to non-linear relationships, we may never overcome this calibration problem. However, this is where other proxy types will hopefully step in. Of course, the multi-proxy approach is a whole other Pandora’s Box of problems, but it is likely the only way to go to glean a more robust picture of past climate for the last 1000 years – at whatever scale.

  70. Pat Frank
    Posted Feb 11, 2006 at 3:23 AM | Permalink | Reply

    #63 Steve, I wasn’t trying to imply that Rob is dishonest; sorry if I caused any discomfort. I’m just trying to understand what’s going on. I don’t know all the players, and didn’t know who was the lead author on Rob’s 2006 paper. None of the names are starred on the 2006 JGR paper, but Rob is starred on the 2003 Holocene paper, so I thought he was senior.

    By the time I was a post-doc, I was writing the papers and choosing the citations. Any young scientist of conventional professional integrity would find it necessary to include directly relevant work, even if only to write a complete discussion. So, then, was M&M included by the writer of the paper, only to be taken out again by someone more senior? Your work with Ross is central to the debate about proxies, Steve. There’s no excuse consistent with competence and/or integrity for leaving it out.

    I’d also still like to know how it is that O&B get big media play, while a better paper, DWJ06, gets roundly ignored. It seems as though news media are equally guilty of cherry picking. I wonder whether it’s conscious prejudice or mere lazy incompetence. If the latter, it’s certainly a bad habit of long-standing.

    Recently, I exchanged several emails with a science reporter at the San Francisco Chronicle about an article concerning the warmed California Current. It looks to be following the Pacific Decadal Oscillation, rather than any linear warming trend. After several go-rounds, complete with many citations to literature, I showed that virtually every point in the story, salient to AGW, was mistaken. The reporter wasn’t moved a micron. After awhile I got the feeling that “science reporter” or not, that person plain hadn’t the understanding to make an independent judgment and was perhaps afraid to go against the authoritative status quo. Maybe that’s the problem with the rest of the media. They don’t know what they’re talking about, and just go with the biggest gun and loudest shouter because they’re afraid to look foolish.

    #69 — You’re not subtle directly but are wrong implicitly, Tim.

  71. Pat Frank
    Posted Feb 11, 2006 at 3:34 AM | Permalink | Reply

    #70 – Rob has anyone thought to sample tree rings for 18-O and see whether the widths and the delta 18-O of the identical set of TR’s tell the same temperature story? They should do, shouldn’t they? They’re both chiefly dependent on temperature, aren’t they?

  72. Posted Feb 11, 2006 at 3:58 AM | Permalink | Reply

    18-O holds great promise although I think the isotope guys are still very much at a pioneering stage.
    I think this paper will soon be published, but it focuses on precipitation.
    Treydte K, Schleser GH, Helle G, Winiger M, Frank DC, Haug GH, Esper J (in review) Millennium-long precipitation record from tree-ring oxygen isotopes in northern Pakistan. Nature.

    I am just starting a 4 year EU funded project where one of the primary aims is to develop long isotopic TR records in Europe.
    I think we will have a much clearer picture in a few years.

  73. Spence_UK
    Posted Feb 11, 2006 at 5:27 AM | Permalink | Reply

    Anyone like to compare the level of media attention to O&B in comparison to the following article?

    I’m not especially convinced that the Russian astronomer is any more likely to be correct than people predicting warming, but I’m not convinced he is any more likely to be wrong either…

  74. Louis Hissink
    Posted Feb 11, 2006 at 6:07 AM | Permalink | Reply



    I managed to find NCDC absolute temp data (now removed from the server but I have a copy, fortunately) from 1880 to 2005 and fitted a linear fit. In 2020 the MGT was estimated to be 10.7 dC by extrapolation, confirming the Russian prediciton we would be in future cooling period.

    I posted a couple of comments on my blog and following posts looked at CO2 and the last 30 years.

    The sudden disappearance of the absolute global mean dataset is perplexing – Junkscience used it to plot the GMT vs CO2 but it was not on their main page.

    My posting of it was only in the last couple of weeks, and given my site’s Google hit rate, maybe I should not have posted it. Too bad, it’s water under the bridge now. But missing data is a serious issue since I now cannot back my claims up anymore by referring to the NCDC source.

    This business is starting to become serious indeed.

  75. Ian
    Posted Feb 11, 2006 at 1:34 PM | Permalink | Reply

    #70 Rob, I asked this question on realclimate, but didn’t get what I was looking for. Do you know of a publicly available paper/report/whatever (URL), that shows the correlation between temperature and tree ring widths? I have searched the Internet and the only thing I could find was, which he indeed does show a good correlation but only of the high frequencies ( What would be far more interesting is to view the correlation of an area where a significant trend has taken place (first one direction than another would be ideal of course). I would think that this would make the strength of the connection a lot stronger (I could correlate the low frequencies of the static on my radio with a trendless temperature region and get a pretty good match — with enough averaging they will both be flat).

  76. Ian
    Posted Feb 11, 2006 at 2:54 PM | Permalink | Reply

    Actually I see several good correlation articles on this site. Not sure why they didn’t show up in Google search. I guess I must have been using poor search terms. Anyways it is clear that there can be a very good and strong correlation. I’m convinced ;-)

  77. Louis Hissink
    Posted Feb 11, 2006 at 6:18 PM | Permalink | Reply

    Re # 76


    Fig 2 in your reference above – I don’t see much correlation at all between width and temperature – there is an obvious decrease in width from 1900 and a return to previous widths around 1950. The corresponding temperature plot is essentially static by comparison.

    Some of the peaks correspond, but the trends? No. So another factor(s) is affecting tree-widths in addition to temperature.

  78. Ian
    Posted Feb 11, 2006 at 7:27 PM | Permalink | Reply

    Re #78


    This was my major concern with the examples I had found previously. There was a strong correlation with the high frequency ‘jitter’, but poor correlation with what counts for climate analysis — the low-frequency trends. I thought I had found a good example on this site, however I did not pay close enough attention to what the proxy was and I was actually looking at a non-tree ring proxy (whoops). So I am back to where I was before, looking for evidence that tree ring widths have been shown to correlate strongly with temperature trends from sensor temperature data. You would not think finding this evidence would be very difficult since a lot of science seems to rest on this theory.

  79. Ian
    Posted Feb 11, 2006 at 7:49 PM | Permalink | Reply

    This paper shows a strong trend correlation I believe —

  80. Louis Hissink
    Posted Feb 11, 2006 at 9:39 PM | Permalink | Reply



    I get a serious security warning with IE7 going to your link, and it’s French too.

  81. Steve McIntyre
    Posted Feb 11, 2006 at 10:00 PM | Permalink | Reply

    #76 – Ian, if you click on the Category in the right frame Post-1980 Proxies, you’ll see a few relevant posts and references. Especially the post on upside-down quadratics shows some botany diagrams of tmperature-growth relationships. The lineage of the concept of tree rings as a way to measure temperature is actually a bit interesting and maybe more subtle than it appears at first glance. Dendrochronology seems to have started out as a means of dating archaeological sites, progressed into the study of drought and morphed into the all-purpose temperature proxy. Jacoby has been very influential in the latter. Fritts is a standard text that’s usually a good starting point to get one’s footing.

  82. Ian
    Posted Feb 11, 2006 at 10:32 PM | Permalink | Reply

    It seems there ‘can’ be a strong correlation as in the link I posted. Here is a link to the abstract —

    Louis – Strange that you got a serious security warning. This is a NRC site, which is the Canadian National Research Council (explains why french and english). The PDF I saw was not in French either. However, I am using Firefox but it seems strange this would make any difference. The name of the paper was “Relationships between anatomical and densitometric characteristics of black spruce and summer temperature at tree line in northern Quebec” in case you want to search for an alternate source.

    I was doubtful that a strong correlation occured at all, the idea that trees would be sensitive to fractions of a degree temperature change (above and beyond the random variations of precipitation, cloud cover, etc.) seemed absurd to me, but this paper does show it and I’m sure other do to. I’m still ‘sceptical’ but less so now. However as Steve pointed out (I looked at those post Steve, very interesting), the situation is much more subtle.

    I will look for Jacoby and Fritts. Thanks for the reference Steve.

  83. john lichtenstein
    Posted Feb 11, 2006 at 10:40 PM | Permalink | Reply

    Peter Hearnden’s complaint that Steve M hasn’t made a reconstruction and therefore his criticism of reconstructions should be discounted reminds me of the criticism one sees from perpetual motion machine investment schemes of their critics. One often hears “Well you say this perpetual motion machine doesn’t work, but where is *your* perpetual motion machine?”. Other frequent complaints about critics are “Why should the company answer bashers?” (ala Steve B) and the ever popular “You must be funded by the oil companies/short sellers/CIA/Sith”.

  84. Posted Feb 11, 2006 at 10:49 PM | Permalink | Reply

    Yeoman work, Steve.

  85. Steve McIntyre
    Posted Feb 11, 2006 at 11:25 PM | Permalink | Reply

    When you think of the complaints that I get from Peter about not making a reconstruction, it’s ridiculous that Ammann and Wahl should be trying to publish an article about the supposed iniquities of “our” reconstruction.

  86. Luke Lea
    Posted Feb 12, 2006 at 12:08 AM | Permalink | Reply

    I plead complete ignorance concerning the technical issues involved in this debate. Furthermore, I am not at all adverse to the possibilty of human-induced global warming. It seems perfectly plausible.

    That said, I detect something unmistakably amateurish in the way the authors of RealClimate conduct themselves, a kind of casual, hand-waving ad-hocracy in their method of reasoning, which does not build confidence in the conclusions they draw.

    As a layman all I can say is that if they are the best the climatalogical establishment has to offer, then maybe there is a problem with the position they hold.

  87. Louis Hissink
    Posted Feb 12, 2006 at 12:30 AM | Permalink | Reply

    Re #83


    well it’s Internet Explorer V 7 beta 2, and it screamed about a security certificate, went flashing pink, and all I could was huh?.

    Got to the site ok, found the english abstract, and then stopped by a password gate.

    I’ll have another try.

    Incidentally Milloy has new global temp data posted on Junkscience just now. Global temps have “changed”. Have not seen them yet.

  88. Steve McIntyre
    Posted Feb 12, 2006 at 7:17 AM | Permalink | Reply

    Louis, I don’t think that the article in question is on the internet. BTW it refers to density rather than RW and, from the abstract, seems to be a discussion relating anatomic features to density, but maybe there’s more to it.

  89. Peter Hearnden
    Posted Feb 12, 2006 at 8:59 AM | Permalink | Reply

    One often hears “Well you say this perpetual motion machine doesn’t work, but where is *your* perpetual motion machine?”.

    Do you? Oh, and you don’t find me making accusations Steve is fossil fuel interest funded. He, it seems, has had some vague associations with such, but, to the best of my knowledge, Steve is just a prodigiously hard worker – a real terrier.

    My criticism is that it’s easy to critice it’s not so easy to construct (crikey, people here criticse me for that). We can all critise a painting (pull it’s brushwork apart, claim it lacks merit) but few of us bother to paint.

  90. BradH
    Posted Feb 12, 2006 at 9:19 AM | Permalink | Reply

    My criticism is that it’s easy to critice it’s not so easy to construct

    Oh, really, Peter. And what do you construct in your real life?

    Bridges? Buildings?…Or superficial artifacts of a reality which exists only in your vivid imagination?

    Add something meaningful to the blog, or go join the make-believe creatures in Narnia.

    [Ad Hom? No, just frustration at your unending inanity. You’re not a scientist, nor am I. So, I’ll challenge you – every time you say something stupid on this blog, I’ll let you know. ;)

  91. Posted Feb 12, 2006 at 9:25 AM | Permalink | Reply

    That’s certainly true. It’s a lot easier to criticise something than do it. But does that make art critics useless? (Well, they are kinda). There is, however, a big difference between criticism and constructive criticism. Everyone should welcome constructive criticism.

    I think in this case it takes somebody from outside the community to look in and say “hey, this isn’t right” and help put them straight. M&M come from industries where full disclosure is mandatory for very good reasons, and those reasons apply as much to science, if not more, than they do to business.

    If the scientific community were willing to make sure everything that is published is fully disclosed and properly reviewed, I don’t think it would be necessary to have critics from outside the community. However, for political and other reasons, that does not seem to be happening. It’s not just the climate field either.

  92. BradH
    Posted Feb 12, 2006 at 9:36 AM | Permalink | Reply


    Hey Nicholas,

    Yes, there are industries in which full disclosure is the “holy grail” and failure to do so results in either fines or jail time.

    I must admit that I remain astonished that any large newspaper, given their profiles, don’t require that their science reporters have science degrees.

    Now, I know that a degree in any field is no guarantee of expertise, but it’s a hook to hang the skin on, should they publish something which is patently ridiculous.

  93. Hans Erren
    Posted Feb 12, 2006 at 10:00 AM | Permalink | Reply

    re 90:

    The criticism on the painting is very fundamental, the argument being that the paint is useless to paint a picture at all.

  94. Spence_UK
    Posted Feb 12, 2006 at 10:24 AM | Permalink | Reply

    There is a huge difference between art, politics and science, that as a non-scientist I think Peter is struggling to differentiate between.

    Politics and art are subjective – a spectrum of viewpoints can be equally valid, depending on how individuals value different attributes. For example, the balance of civil liberties and security is a hot topic at the moment, and people have different views and nobody is “wrong” per se.

    Science is different. In science, problems can be formulated, and their accuracy (and efficacy) can be measured, and quantified. An inaccurate answer is worse than saying we have insufficient data to formulate an answer, and unlike in art and politics, it can be as difficult – and important – to correctly criticise (i.e. analytically) a piece of work as it is to complete the work in the first place.

    Consider the view of John Ioannidis, Greek epidemiologist:

    “Negative” research is also very useful. “Negative” is actually a misnomer, and the misinterpretation is widespread.

    It is this misinterpretation that people like Peter and others are leaning heavily on in an attempt to find something disagreeable about Steve’s work.

  95. Steve McIntyre
    Posted Feb 12, 2006 at 10:52 AM | Permalink | Reply

    I don’t think that art criticism is a very apt analogy. Why not compare to “auditing” as in the blog title. When you buy stocks, as an investor, you want the financial statements to be audited. This is done for small corporations. We’re talking about policies being used to justify expenditures much greater than little corporate securities offerings. What’s the harm in auditing the scientific studies? Why should we decide on policies based on “unaudited” statements? No one would ever tell an auditor – if you don’t like the way we’ve done the accounts, start your own business.

    Look, I’d be quite happy to be able to develop my own view of climate history, but that’s a different enterprise.

  96. Ian
    Posted Feb 12, 2006 at 12:25 PM | Permalink | Reply

    #88 #89

    Strange that no one can access this paper but me. I downloaded it and put it on another server here —

  97. Posted Feb 12, 2006 at 3:44 PM | Permalink | Reply

    Remind me again of the work in the field you’ve done, Peter?

  98. John A
    Posted Feb 12, 2006 at 4:01 PM | Permalink | Reply

    Re: #98 As a farmer, Peter’s field work involves spreading muck on them. He’s rather good at it, as anyone who has been on this blog can attest.

  99. Peter Hearnden
    Posted Feb 12, 2006 at 4:32 PM | Permalink | Reply

    Re #91, Brad, you’re doing this – . I can see you’re not stupid, I’m not either – OK?

    Re #98 ‘SPQR’ you’re helping ‘John A’ to do this – . ‘John’ you’re clearly not stupid – please accept I’m not, OK? You KNOW I’m no more, probably less, of a mud slinger than you.

    Please all just accept my view is that, while not perfect, the recons are worthwhile and give a better idea of recent temps than, say, Lamb did. That’s all – I just think otherwise to you guys – OK??? If asked for evidence I’ve tried pointing to all the usual places, you all dismiss them. I can’t point to anything else.

    Don’t like it? Then ban people like me :)

  100. John A
    Posted Feb 12, 2006 at 4:47 PM | Permalink | Reply

    Re #98 “SPQR’ you’re helping “John A’ to do this – . “John’ you’re clearly not stupid – please accept I’m not, OK? You KNOW I’m no more, probably less, of a mud slinger than you.

    Nope. You’re out there on your own in the muckspreading and well poisoning stakes.

    Oh an by the way, when I tried to post a comment on john Fleck’s weblog, the spam filter blocked me. Funny old world isn’t it?

  101. per
    Posted Feb 12, 2006 at 6:07 PM | Permalink | Reply

    Peter Hearnden said:

    I just think otherwise to you guys

    Thank goodness. In the meantime, it would be awful helpful if you could back up any of your assertions with reasoned argument, rather than merely asserting ex cathedra that MBH are right.
    many thanks

  102. Terry
    Posted Feb 12, 2006 at 6:54 PM | Permalink | Reply

    There are hundreds, if not thousands, of tree ring sites. Briffa [2000] has reported that the vast majority of these sites have failed to record increases after 1960, contrary to the hypothesis that there is a linear relationship between temperature and ring width.

    This baffles me. If this is, indeed, true, then this whole line of research is silly. If tree rings are unable to detect temperatures as high as modern temperatures, then they have no ability to tell us whether historical temperatures were as high as modern temperatures.

    Can someone tell me why we are paying attention to tree rings at all if this is true? Perhaps Mr. Bloom if you are listening can give me the other side of the argument here. (You seem to know what you are talking about.)

    Someone please educate me.

  103. John A
    Posted Feb 12, 2006 at 7:05 PM | Permalink | Reply

    If this is, indeed, true, then this whole line of research is silly. If tree rings are unable to detect temperatures as high as modern temperatures, then they have no ability to tell us whether historical temperatures were as high as modern temperatures

    You’re not the only one. Maybe if Keith Briffa gets to present in front of the North Committee, someone might ask him to resolve these observations with his work on O&B[2006]

  104. Louis Hissink
    Posted Feb 12, 2006 at 7:39 PM | Permalink | Reply

    Re #89


    Yes I spotted that difference “anatomical”, and Ian has since managed to get a copy so I’ll get it from there.

    And #101 JohnA, you got posted – and he calls Lubos, “Lumo” – bit snide.

  105. Louis Hissink
    Posted Feb 12, 2006 at 7:54 PM | Permalink | Reply

    Re #103


    where did you get that reference to Briffa (2000) from? I have been scrolling up and down this thread and cannot easily pick it, unless you found it elsewhere.


  106. Louis Hissink
    Posted Feb 12, 2006 at 8:01 PM | Permalink | Reply

    Re # 97

  107. Posted Feb 12, 2006 at 8:05 PM | Permalink | Reply

    Re #106, Louis

    The reference is a paragraph in Steve Mc’s post titled: Proxy Selection


  108. Peter Hearnden
    Posted Feb 13, 2006 at 2:35 AM | Permalink | Reply



    I’m sorry, but my experience is that no kind of reasoned arguement that involved any member of the ‘team’ will convince you. I might be wrong, but, somehow, I doubt it. I don’t know what amount of warming over then next decade of two might change your mind – please let me know how much.

    I like your emphasise of my name btw – out of sympathy for the fragrant John A’ perhaps?

  109. per
    Posted Feb 13, 2006 at 7:54 AM | Permalink | Reply

    Peter Hearnden said:

    my experience is that no kind of reasoned arguement that involved any member of the “team’ will convince you…

    Dear Peter
    I am sure you will not mind sharing with us this experience where you have actually tried to make a reasoned argument based on the facts ? Perhaps a URL ? All i can recall are numerous examples, including this exchange, where you simply resort to assertion that you are right, and refuse to justify why.

    I don’t know what amount of warming over then next decade of two might change your mind…

    Perhaps you are confusing two issues here. They are;
    1) are the paleoclimate reconstructions robust ?
    2) have global temperatures risen recently ?
    the answer to (2) is almost certainly yes; but that does not tell us the correct answer to question (1). Nor does it tell us about the merits, or otherwise, of current models of global climate.

    Your conflation of 1 and 2 is notable, and is I suspect, part of your religious belief in AGW.

  110. Peter Hearnden
    Posted Feb 13, 2006 at 9:19 AM | Permalink | Reply

    Oh don’t be so absurd David…I don’t religiously believe in anything and, for that matter, I don’t think you do either.

    We don’t agree. My view is you’ll dismiss anything I post in support of my view. But, to test this, try the IPCC or RealClimate section on recons and tell me you don’t just dismiss them. I think those people have it *about* right. I’ve NEVER said the recons are perfect. Otoh, I don’t think the CA views that you can just dismiss the lot of them because of minor mathemnatical errors or guilt by association with other ‘team’ members stacks up.

    Oh, and when you reply do keep this in mind please – .

  111. JerryB
    Posted Feb 13, 2006 at 10:12 AM | Permalink | Reply

    Re 105,


    Lumo appears to be Lubos’ own nickname for himself. It is how he signs his blog entries.

  112. Dave Dardinger
    Posted Feb 13, 2006 at 10:30 AM | Permalink | Reply

    Peter, a reasoned argument does not consist of a reference to someone elses work and saying “Prove them wrong!” It would consist, in this case, of your presenting the logic (at least) of the source’s argument and then providing a link or reference to allow the reader to check that you’ve done it properly.

    And in the case of climate reconstructions, that’s the entire debate here. I’ve you’ve read material on this site with even a grade-school comprehension you know WHY the climate reconstructions are rejected as being unproven. There’s bad proxies; reliance on models rather than reality; failure to apply realistic corrections for UHI, etc. The bad math and group-think are also reasons to doubt the results, and the speciality of this blog, but hardly the only reasons to reject the ‘concensus’ climate reconstructions as proved.

  113. Peter Hearnden
    Posted Feb 13, 2006 at 1:07 PM | Permalink | Reply

    Dave, neither is a reasoned argument about constantly trying to make out those who disagree are stupid (or greenies, or enviros or wackos or etc etc etc ad infinitum)…Read the John Fleck post I’ve linked to several times – it’s very good. Besids, you must know the links to the IPCC or RC by now?

    So, the idea is all the ‘team’ are wrong? Every one? All in on some deception (it must be a deception since they can hardly not have heard of Steve)? Nope, I’ve gone off conspiracies big time.

    At root it comes down to this: Most here, all probably, think there was a MWP and a LIA. So do I. The difference is I/we think both were modest and that now is *likely* to be the warmest time for 1000 years but people here are sure the MWP was warmer. That’s the knub. No one here would be here if it was accepted the MWP was warmer than now and the LIA of greater magnitude as well. Why do I say that? Because it’s MBH99 and the following you’re after – NO ONE here has done the slightest bit of digging around what Lamb did have they! No one had demanded he be replicated! It’s not climate recons this place is about, it’s after the ones it doesn’t like!

  114. Louis Hissink
    Posted Feb 13, 2006 at 1:40 PM | Permalink | Reply

    Re # 112

    Oh really? Oh well, my error. Mind alot of what Lubos writes re string theory etc glazes my eyes, so I probably missed his use of it.


  115. ET SidViscous
    Posted Feb 13, 2006 at 2:00 PM | Permalink | Reply


    It’s less about the MWP and LIA, those are just recent enough that things like trees are alive know, or are around now that were then. The real question is wether or not our current climate variability (modest warming for the 20TH century) is abnormal from normal natural variability.

    The MWP/LIA discussion is a way to distract from previous natural events that we KNOW existed that show natural climate changes can be dramatically more than we are seeing now.

    The question of whether natural climate changes can be more drastic than 20th century changes is answered simply.

    Where both you and I live it was once covered with a ~kilometer of ice. This is not up for debate, we knows this from a variety of evidence, we do not know the global mean temperature at that time to 1/10th of a degree, but we know, without a doubt, that it was significantly cooler. We also know that at various times in the distant past it was also significantly warmer. Now that we can all agree that the climate CAN change without anthropogenic influence, we can stop arguing about that right? So now we can move on to the current situation. Since we know that IT IS POSSIBLE for the climate to vary naturaly, is our current modest warming natural or anthropogenic.

    Arguing about the MWP/LIA last 1000 years and so forth is a complete misnomer.

    Two questions Peter (I may have asked them of you before)

    1. Since we know that climate varies at every time level (Seconds, Minutes, hours, days, weeks, years, decades, centuries, etc) naturally, There must be some natural variation in the 20th century. How much of the ~0.6C warming was natural and how much anthropogenic.
    2. How much influence does solar output have on climate?

  116. Dave Dardinger
    Posted Feb 13, 2006 at 2:24 PM | Permalink | Reply

    re #114

    Calling people names isn’t the issue. And I’m a big-boy and can take them is someone wants to call me one. But it isn’t names, it’s the actual science that’s at issue. Where is Mann or one of his team over here actually discussing why Steve who whoever is wrong in his analysis of MBH98 or it’s followers?

    And even when it comes to names we’re quite mild here. The other day Tim Lambert complained about being lumped in with those, such as yourself, who call for Steve to do field-work / his own recon. Tim promptly got a retraction and an apology. But even Tim is unwilling to discuss the actual scientific issues.

    And, BTW, trying to disguise your argument from authority as rejection of conspiracy theories just won’t cut it. It doesn’t matter whether there’s one or a hundred principal scientists who believe in and promote AGW, the question is whether or not they can and do publicly debate the issues critics raise about it? They seem to be unwilling to do so.

    Now if you want to quote individual statements from RC or IPCC and state why that particular statement proves something at issue, fine. But you’ve got to put the ball in play before we try slamming it down your throat.

  117. Steve Sadlov
    Posted Feb 13, 2006 at 6:00 PM | Permalink | Reply

    RE: BBC Propaganda Team

    In classic form, the Beeb sent a crew to Churchill to do a “Plight of the Polar Bear” bit last year. Of course, they had to pick September (the annual ice minimum) to do their shoot. The camera panned to view Hudson’s Bay and lo and behold…. blue water! Poor Polar Bears. They had also managed to find some sycophant locals to testify that “we just don’t get ice like we used to in these here parts …. and now the bears root through our rubbish” ad naseaum. Now, far be it for me to imagine that in a (sarcasm on) high income community(sarcasm off) such as Churchill, that a carefully stationed fee into locals’ hands might not result in some really great testimonials.

    Oh and by the way, 2005′s melt was a pretty good one, so the dramatic effect was high. Of course, the fact that even from that well melted baseline as of late summer early fall, we’ve seen a pretty darn good freeze up this winter, with sea ice extent at ~ long term mean levels, has not since been mentioned. No stories about the freezing Polar Bears.

  118. Peter Hearnden
    Posted Feb 14, 2006 at 3:49 AM | Permalink | Reply

    #116, etsv, 1. Quite a lot actually, 30% perhaps more. 2. When solar output changes climate climate changes. The evidence that I think of merit shows that at present solar output hasn’t changed enough to account for the warming seen.

    #117 OK, then if I call you a ‘prat’ (and, to be clear this is for the sake of argument – you’re not :)) it adds to the debate? No Dave , i t d o e s n o t. You’re an avowed big boy, why do I have to spoon feed you the IPCC report or RC? But, if that be the need, I suppose I could find refs for you.

    #118 . (sarcasm on) so, we better go to Fox News for impartiality? Oh and the BBC should have said ‘Across the Arctic average ice extents are rising’? (sarcasm off).

  119. Dave Dardinger
    Posted Feb 14, 2006 at 6:56 AM | Permalink | Reply


    If you call me a prat do I have to take a pratfall?

    As usual, you miss the point. Being civil is desirable, but it isn’t the purpose here or anywhere, and it is a two-way street. Be civil and thoughtful of others and you’ll be treated likewise.

    But the point of debate and of scientific discussion is to provide points of discussion. Saying “read RC” or “read the IPCC report” don’t provide any points of discussion. Further they’re insulting (see paragraph above) and will cause the recipient to treat you like a prat. I’ve read much at RC and much of the IPCC report and your implying indirectly that I haven’t is an crude attempt at a putdown.

    More importantly, unless a precise and quotable position is available, a discussion won’t have a focus. I’m sure, for instance, that I could go to RC and produce a pull-quote to take issue with. But then you’d complain that it wasn’t what you meant and we’d have gotten nowhere. If you quote a specific paragraph, then those who disagree can focus on that paragraph and either say, “sure we agree with that, so what?” or “Come on, Peter, Steve has blasted the team out of the water on that point in “….” where he said, “….” Then the fun can begin.

  120. ET SidViscous
    Posted Feb 14, 2006 at 8:12 AM | Permalink | Reply

    1. SO then Anthropegenic warming has been ~.42C – .56C over the 20th century? Where is your backing for the 30%?

    2. The evidence against your second comment is that to the first order, the changes in GMT over the 20th century mathces changes in colar output, helluva coincidence if not so. But if you could point to a reference that shows what for a given X change in solar output we would get a Y change in GMT, we can readily check the hypothesis.

  121. Posted Feb 14, 2006 at 9:23 AM | Permalink | Reply

    There was a study which showed there was a roughly 100% positive feedback for changes in solar output. In other words, if solar output goes up by 1W/m^2, we should expect an increase in net radiation at the surface of 2W/m^2. Sorry, I can’t remember where I found the paper (from this blog somewhere, probably). It was based on a study of historical instrumental data I believe. If I find it again I’ll bookmark it and post the link.

    Last I checked, this explained at least 1/3 of observed increased radiative heating at the surface, possibly a lot more, depending upon which measurements you use to compare it again.

    The observed output of the sun in the visible/infra-red range has increased by 2W/m^2 during the early 20th century. If the feedback study is correct, that should mean an increase of 4W/m^2 at the surface due to the positive feedbacks. I believe the observed range is something like 5-10W/m^2. However, that is from memory.

    Interestingly, the increase in solar output started around 1900 which is also the point where many of the indicators may suggest there was warming. It pretty much hit current levels around 1950, and if I remember correctly, there was an observed global cooling for a while in the period 1945-1975 or so.

    (Graph of the solar output here).

  122. Peter Hearnden
    Posted Feb 14, 2006 at 11:03 AM | Permalink | Reply

    Re #120

    Dave, OK, you’ve read the IPCC and RC (and I didn’t mean to imply you haven’t – part of the reason I didn’t quote either is I’d expect you to have read them :)).

    But, were both asking each other for specifics. I tell you what I’ll do, I’ll spend some time thinking about what has and does lead me to think as I do, you do the same. I am, I have to admit, too busy reading and posting stuff and it might take me a day or two… but I’ll do it. For both of us (to, in part, quote you) it should consist, in this case, of presenting the logic (at least) of the source’s argument and then providing a link or reference to allow the reader to check that we’ve done it properly. Not bogged down in statistcs, or whatever, the basics. Why? Becuase it people with far less knowledge than you or I we have to convince.

    Re solar output, an interesting link from Ukww today (it’s page 14 and, for those of a sensitive nature, the whole document is stickless)

  123. fFreddy
    Posted Feb 14, 2006 at 1:09 PM | Permalink | Reply

    Re #123, Peter
    Seems to me the key part of your link is on page 13 where it says “… it has been shown that long-term trends in the aa index and cosmogenic isotopes … do not necessarily imply equivalent long-term trends in solar irradiance … ”
    The rest of the article goes through the usual morass of “may”s, “could”s and “possible”s, and concludes that we don’t really understand this yet (which is fine).
    So, possibly more problems with proxies. Can you point out some background to the assertion quoted above ?

  124. Posted Feb 14, 2006 at 10:40 PM | Permalink | Reply

    Peter, what is obvious is your continual hypocrisy.

  125. Steve Sadlov
    Posted Feb 16, 2006 at 3:50 PM | Permalink | Reply

    RE: #119. You mentioned Fox News, I must say I have not personally seen that company’s own hysteria tinged reports regarding reputed AGW. I did personally see the one from the Beeb which I referenced. In any case, hysterical reporting of this sort seems to be endemic to most of the main stream media. As for your comment about what would have been a suitable title my own recommendation would be “Wow, another September ice extent minimum in Hudson’s Bay: Something almost as exciting as watching the grass grow”

    I can see the Beeb’s 2006 update brewing. And since they seem to prefer a locale, such as Churchill, at one of the world’s most southerly annual sea ice occurrence locations (e.g in order to ensure that the odd norther will not cause an unexpected late summer ice pack build up, such as may occur in Barrow and other truly northern places), I can offer up a brilliant recommendation for next year’s update. I can see it now, my creative juices are flowing:

    [September 14, 2006 - Pan shot of the Sea of Okhotsk, somewhere in Hokkaido....]
    “The poor fur seals, they are rooting through the rubbish bins of the local Sushi restaurants, because …… [pause for drama]…. THIS YEAR …. there is NO ICE FOR THEM TO WALK ACROSS TO GET TO THEIR MACKEREL!”


  126. Posted Feb 17, 2006 at 3:42 AM | Permalink | Reply

    In my opinion, any climate reconstruction has more or less problems. You can not be sure that this reconstruction is better than another one and more reliable than others in spite of any advanced methodology. I’d like to point out several reasons. Firstly, the Geoscience research has some uncertainties in nature, and one should not see it logically and stricktlylike Physics and Mathematics. Second, any temperature reconstruction is based on tree rings, ice cores, and other proxies. However, all the proxies have many problems in one way or another. For instance, tree ring proxies, whether tree ring width or isotopes, are non-linearly influenced by many factors including temperature, precipitation, soil and others during the different time spans since its germination. It is difficult that one reconstruct only temperature or precipitation. Therefore, any scientist, who think his reconstruction is more believable than others, is not honest and even not scientific. Third, there are so many uncertainties in paleoclimate reconstruction, the discussions themselves are not meaningful for any scientist and audience. The produced results are the doubt for science journals from the audience. Fourth, the dispute of the 20th century warming has included non-scientific factors such as personal feelings. A noticeable example is that one group does not cite anther group’s references in their published paper although the theme is directly correlative. It is very questionable and unbelievable for me and any integrity scientist, although you have completely different viewpoints from others. Totally, the dispute is of no use for improvement for temperture reconstructions. What I see is that one paper appears after another paper and the frequency of citation is increasing quickly. My opinion is that you have to examine each part of one whole paper and participate in each step of one experiment process before you give a different idea, because each paper has go through peer-reviewed process before it is published. Especially, sometimes it gives me a feeling that I don’t believe anything and don’t believe anyone. It is awful. I hope that any scientist should have a fair, careful and healthy altitude to examine the work by scientists. It is not advisable that cherry picking is also adopted in criticism for one paper. I must state that these words don’t attempt point to anyone and it is only my opinion.

  127. Posted Feb 17, 2006 at 6:34 AM | Permalink | Reply

    I am very glad that someone is interested in our paper. I would not wanted to make comments about these discussions because it is not correct in many ways and meaningless. However, in some way I feel I should give my ideas. I have more than 10 years of working experience for historical temperature reconstruction and thus I should have priority to say how well the data used are in our paper. These data in China are chosen based on both time resolution and representativity of temperature change. In our paper, we gave three temperature composites in China during the last two millennia using different ways. The three composites show good agreement between one and another (please see the original paper), indicating good confidence of our reconstructions. Specifically, I don’t agree with Steve. About Dulan tree-ring width chronology, new width data from nearby region (Shidalong) representing winter temperature change are consistent with Dulan series usded in our paper in trend variations, giving strong evidence that Dulan chronology is an indicator of temperature change at leastin low-frequency domain. For Dunde ice-core chronology, we adopted the series with 50a resolution, because this series has the most ice-core samples (more than 7000) than other series. Concerning more details about the ice cores, I have no right to say whether the data is how well or not. Although there are some different ideas about temperature-sensitivity of the ice-core data, there are extensive agreement between Dunde data and the temperature series from parts of China. Therefore it is no question that the Dunde-ice core represent temperature change on long-term timescales. The other series are also good indicator of temperature change. If one still has doubt about the data we used, please examine our paper more carefully and revisit the original references before making further comments. Thank you very much for your attention!

    Steve: See my reply here

  128. Steve Sadlov
    Posted Feb 17, 2006 at 10:45 AM | Permalink | Reply

    RE: “Junipers in the western U.S. are strongly associated with moisture (see Paul Knapp and others) and negligibly associated with temperature.”

    A brilliant demonstration of this fact can be seen is an ecological cross section from the Pacific Ocean running northeast through downtown Los Anglese then out into the Mojave Desert. There is a distinct band where junipers thrive, utterly and absolutely delimited by average annual precipitation amount.

  129. Dano
    Posted Feb 17, 2006 at 12:10 PM | Permalink | Reply

    Junipers gobble up grasslands

    Growing problem – Warm weather and aggressive fire suppression help thirsty junipers outcompete pasture grasses and sagebrush, and sink their roots into large swaths of rangeland across Central and Eastern Oregon
    Sunday, October 02, 2005

    Behold the scraggly juniper. It is taking over Oregon.

    The prickly, pungent native tree has found a way to flourish across Eastern Oregon, changing the landscape and soaking up precious water as it goes. It has sunk its deep and tenacious roots into about 10 percent of the state so far and is gaining ground more quickly than anyone realized, a new survey by the U.S. Forest Service shows.


    Susceptible as seedlings

    Wildfires once torched many seedling junipers before they got going. Beginning near the turn of the century, livestock grazing started clearing native grasses that fed the blazes, and crews later began extinguishing whatever flames did manage to get a foothold.

    The weather has probably helped, too. Records suggest the past century has been a little warmer and wetter, which would also favor the spread of junipers.

    Nobody knows for certain, but Miller suggests that rising levels of carbon dioxide in the atmosphere from the burning of fossil fuels may be helping junipers spread. Carbon dioxide acts as a kind of invisible fertilizer, helping trees pick up their pace.



  130. Posted Feb 17, 2006 at 4:19 PM | Permalink | Reply

    Apologies, as I missed comment #101, in which John A. suggested he’d been blocked by my Spam filter. Sorry, John, not sure about the explanation. There are a couple of comments from you on my blog posted recently that did get through, including one around the time of your post above.

    I don’t see anything in my Spam Karma log to indicate something from you had been blocked, and of course I haven’t done anything to prevent you from posting, as I think that would be inappropriate, whether I agree with you or not.<

    John A replies: Of course not, John. In the course of running a few weblogs myself I have recently come to realise how twitchy and inconsistent spam filters can be. The tone was meant to be ironic rather than accusatory. It was just that having submitted a comment (I may have written a comment on your weblog once before a long time ago) it immediately brought up a page accusing me of being a spammer – so I assumed that my comment had been deleted – an assumption that turned out to be wrong. I accept your explanation without reservation or rancour.

  131. beng
    Posted Feb 18, 2006 at 8:09 AM | Permalink | Reply

    Re#130 Dano, I’m not a botanist, but I have a lifetime laymen’s interest & observational experience w/trees & associated ecologies in the east US. And some aspects are very apparent.

    Virginia juniper (Redcedar) is generally much more prevalent here than in the past. The overwhelming reason are human land-use changes — forest-clearing, farmland abandonment, fire-suppression & pastureland grazing. Browsed pastures are typically kept clear of trees except V. juniper (and thorned shrubs) as cattle won’t eat them. The result is establishment of large, diffuse groves in many formerly farmed and currently grazed or abandoned areas, especially on valley limestone-derived soils.

    Point is, I can say w/reasonable certainty that temperature/CO2/rainfall changes are negligible factors in this expansion here. VA juniper has simply taken advantage of land changes (human or otherwise), as it always has. Textbook old-field succession aided greatly, recently, by fire-suppression and finicky domestic browsers. I’d think the simplest explanation is that the closely related western NA junipers are doing the same thing, except rainfall would be a more limiting factor there as it’s generally drier.

  132. Steve McIntyre
    Posted Feb 18, 2006 at 9:07 AM | Permalink | Reply

    Beng and Dano – I think that some of Craig Allen’s work here is quite relevant. See for example: (and there are many other interesting pages at that site). Look at the ring width chronology with a classic hockey stick shape. I corresponded with Craig Allen about sheep grazing at some of the Graybill sites. He said that at the New Mexico sites that he knew about, there were old shepherd trails very high on the mountains.

  133. beng
    Posted Feb 18, 2006 at 11:00 AM | Permalink | Reply

    S_M, one thing from your above link that’s quickly obvious is the woody-plant increase significantly decreases the land’s albedo. Couple that w/more sequestering of moisture in the trees/soil/shaded areas, and you have non-CO2-caused temp increases, but w/prb’ly a smaller diurnal range. Sound familiar?

  134. TCO
    Posted Jun 10, 2006 at 6:31 PM | Permalink | Reply

    A. Post 14 is a bit outrageous. Rob is a nice guy and I appreciate the effort by anyone to dig a signal out of noise. But the comment on justifying cherry-picking (or PCA) as it was ‘impossible’ to do good sampling was outrageous. He needs to decide ahead of time how the info will be processed and then do real sampling and let the data say what they will say! If you don’t get the story you expected to get, it’s probably because your study doesn’t justify what you want or even any consistent story at all.

    I’m just shocked that Rob is so thick-headed not to understand this. Paleoclimatolgy must not be getting very bright guys. If someone pulled this sort of biased stat crap in medicine (FDA sudmission or even just QA testing in a facility for GMP), they would cut his dick off. He doesn’t even know how wrong he is. I’m in shock!

    BTW, it’s ok to do a series of cores and find out that they don’t tell a story or that you just have some general inferences or after the fact, say what a possible interpretation is. You can even publish it. But he needs to give his thick head a wack and realize that he’s not going to get to publish a “reconstruction”. What he’s going to publish is results of a field survey and some speculative interpretation. And for that it’s CRITICAL (for the advancement of the field) that he includes everything, all the stuff that doesn’t make sense, all the “warts”, etc. in the publication.

    B. I’m not clear why Rob should have had to cite Steve. Read some of the comments here about it, but didn’t see one that said a specific thing of Steve’s that needed a cite (for example a method from Steve or the like). Steve’s papers are pretty much restricted to the nitty gritty of MBH.

  135. TCO
    Posted Jun 11, 2006 at 12:57 PM | Permalink | Reply

    I apologize for the colorful language here. Rob, I tend to swagger a bit and throw sailor’s language out. But I like you and mean you no harm.

    I did mean what I said about shock at what I percive as a lack of awareness of suitable data collection/analysis methods to prevent bias. This area would seem to be well touched on in the most basic methods courses, no? On content, this seems to be same issue as what Martin and I were talking about on the other thread, so I appreciate his response.

One Trackback

  1. [...] One of the difficulties in thinking about the various hockey stick-shaped paleoclimate reconstructions, (and by “difficulties” I do not mean the distracting food fights, entertaining as they may be update: let the food fight begin) is that the approach used boils them all down to a single number. That tells you something about overall averaged surface temperatures, but not about spatial extent. [...]

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