What is the evidence against warmer MWP?

Lee has criticized me for not fully canvassing the supposedly manifold lines of evidence marshalled by the NAS panel against a warmer MWP. So I’ve done a little exercise to summarize the evidence AGAINST the MWP being warmer than mid-20th century, disaggregating what I believe to be the salient information from the spaghetti studies. The information is familiar, but it’s arranged below a little differently than I normally arrange it.

In my opinion, there’s a fair bit of evidence the other way – some examples mentioned here from time to time include: Cuffey’s Greenland reconstruction/Dahl-Jensen’s Greenland boreholes; Naurzbaev in Siberia, Millar et al in California, Law Dome dO18 isotopes in Antarctica, Pollissar on glaciers in the Venezuelan Alps, higher treelines in Scandinavia, Lamb’s European evidence; the Polar Urals update, … But that’s not what we’re here for today.

So let’s turn the question around – what is the evidence AGAINST a warmer MWP?

(1) bristlecone and foxtail ring widths (especially those collected by Graybill in the 1980s) are wider in modern times than in medieval times. (OK, the NAS panel has discounted this, but it’s obviously been used over and over as evidence against a warmer MWP in the spaghetti studies.)
(2) ring widths at Yamal, adjusted for age, are wider than in modern times than in medieval times;
(3) the percentage of coldwater diatoms offshore Oman is higher in the 20th century than in MWP;
(4) dO18 levels in some of Thompson’s tropical ice cores and in the overall average is higher than modern levels;
(5) combinations of the above 4 proxies under a weighted average with small numbers of other mostly nondescript proxies show mid-20th century indices slightly higher than the highest corresponding index in the MWP (the spaghetti graphs);
(6) supposedly some evidence from Antarctica according to the NAS Panel, but they did not provide any evidence and I don’t know what it is;
(7) 5000-year organics from Quelccaya (Thompson 2006, cited by NAS panel)

I realize that my arrangement of 1-5 is based on a POV, but have I left anything out from the NAS panel? I haven’t posted anything on (7) yet, but intend to do so. I’ve written extensively on items 1-5; I’ve got a note up on point 6 inviting a response, but nobody has so far volunteered a guess on what the NAS panel, those sturdy engineers and bridge designers, had in mind.

If the parties were in civil litigation or other proceeding to be decided on balance of probabilities, one would weigh the evidence from treelines, crops etc, on the one hand against the evidence listed in points (1-7) or any others to be added to this list. The case for the Team is far from overwhelming expressed like this.


  1. Richard
    Posted Aug 3, 2006 at 4:28 PM | Permalink

    There is also the historical record of sea ice and agricultural production quoted in the book “The Little Ice Age” – a friend is reading it at the moment, so I can’t give you author and footnoted references. But this is a very important question to find an answer to – I think we have to try harder than the NAS panel were to see if MWP really was warmer than today. An important guide to me, working in agriculture myself, is agricultural productivity in terms of wheat yields (abbey records), hay yields etc and time of grape picking etc. Plants are very responsive to small changes in climate.

  2. Paul Dennis
    Posted Aug 3, 2006 at 4:42 PM | Permalink

    Steve, I was reading some of Thompson et al. (2002) on the Killiamnjaro glaciers today. I don’t have the paper in front of me but made a note to go back and check some of the data and ideas they present. Two points occurred to me (the first you have correctly identified yourself):

    1) they want to interpret the oxygen isotope data in terms of a temperature effect, rather than an amount effect. I can see why they should want to do this. In the absence of good dating control and an ice sheet age model they have done some wiggle matching of the isotope series. One of these matches is to the solar activity curve. This procedure implies that temperature is the dominant control on the isotope composition. I have to confess I can’t remember if they measured cosmogenic Be in the ice core as a measure of solar activity.

    This is in effect opposite to the hypotheses for Mount Kenya where the studies of Allayne Street-Perrot, Melanie Leng and others have inferred that precipitation amount dominates the isotope signal. This is what we would expect given our understanding of monsoon dominated precipitation with an Indian Ocean source region.

    2) Not-with-standing the problems with an age model for Kilimanjaro, the ice core data shows a distinct centennial scale periodicity with several periods over the past millenia when the oxygen isotope composition exceeds that of the present day. Using Thompson’s suggestion that temperature is the dominant control then these should represent periods warmer than the present!

  3. Cameron
    Posted Aug 3, 2006 at 5:13 PM | Permalink

    I have seen (twice) reference to coral cores in the pacific that purport to show the pacific was cool during the MWP (one was by Mann at the hearing), but I haven’t seen the paper yet. If true this would dispute the global nature of the MWP as compared to the 20th century. Does anyone know this reference? Paul – you might have a better idea about this study…

  4. KevinUK
    Posted Aug 3, 2006 at 5:15 PM | Permalink

    Not strictly evidence against ut in refering to the ’95 IPCC report Mann referred to the figure showing the MWP and the LIA as ‘the cartoon’. Why did he (and another) call it ‘the cartoon’?


  5. Allan M.R. MacRae
    Posted Aug 3, 2006 at 5:15 PM | Permalink

    Hi Steve,

    Keep in mind it is not critical that the MWP was warmer than today to make the argument that today is not abnormal – the average temperatures only have to be in proximity to one another.

    The ~~2002 literature study re the MWP by Willie Soon and Sallie Baliunas of Harvard may be of use to you. If you need the exact reference, just let me know and I’ll find it.

    Best, Allan

  6. KevinUK
    Posted Aug 3, 2006 at 5:19 PM | Permalink


    You just beat me to it


  7. KevinUK
    Posted Aug 3, 2006 at 5:29 PM | Permalink

    This is a good start



  8. KevinUK
    Posted Aug 3, 2006 at 5:31 PM | Permalink

    With PDF here

    Click to access review.pdf


  9. Douglas Hoyt
    Posted Aug 3, 2006 at 6:10 PM | Permalink

    The following paper indicates that arctic sea ice was less between 1130 and 1300 than during the 1990s, when people claim things are unprecedented. It is evidence of the MWP being warming than now for nearly 2 full centuries.

    Svalbard summer melting, continentality, and sea ice extent from the Lomonosovfonna ice core by Aslak Grinsted, John C. Moore, Veijo Pohjola,TàƒÆ’à‚⴮u Martma, and Elisabeth Isaksson
    Journal of Geophysical Research, Vol. 111, D07110, doi:10.1029/2005JD006494, 2006.(http://www.agu.org/pubs/crossref/2006/2005JD006494.shtml)

    We develop a continentality proxy (1600–1930) based on amplitudes of the annual signal in oxygen isotopes in an ice core. We show via modeling that by using 5 and 15 year average amplitudes the effects of diffusion and varying layer thickness can be minimized, such that amplitudes then reflect real seasonal changes in àƒÅ½à‚ⲱ8O under the influence of melt. A model of chemical fractionation in ice based on differing elution rates for pairs of ions is developed as a proxy for summer melt (1130–1990). The best pairs are sodium with magnesium and potassium with chloride. The continentality and melt proxies are validated against twentieth-century instrumental records and longer historical climate proxies. In addition to summer temperature, the melt proxy also appears to reflect sea ice extent, likely as a result of sodium chloride fractionation in the oceanic sea ice margin source area that is dependent on winter temperatures. We show that the climate history they depict is consistent with what we see from isotopic paleothermometry. Continentality was greatest during the Little Ice Age but decreased around 1870, 20–30 years before the rise in temperatures indicated by the àƒÅ½à‚ⲱ8O profile. The degree of summer melt was significantly larger during the period 1130–1300 than in the 1990s.

    Received 13 July 2005; accepted 18 January 2006; published 14 April 2006.

    Keywords: melting; continentality; sea ice extent.

    In addition, it also worth noting that the Vinland Map (created before 1440) shows the north shore of Greenland and the only way that could be done is by sailing along an ice free coast. The present day coast is ice bound year round.

  10. welikerocks
    Posted Aug 3, 2006 at 7:08 PM | Permalink

    NOAA Paleoclimatology/Global Warming – The Data website
    on these pages site Mann et al 1999 as the source for : “The idea of a global or hemispheric “Medieval Warm Period” that was warmer than today however, has turned out to be incorrect”
    And I found all this from “How to Talk to a Skeptic Guide” ala Coby from RC, who gives the above page for “help” when a skeptic says to you “The Medieval Warm Period was just as warm as today”

    Wikipedia/Medival Warm Period is more of the same and show two graphs with a guide to matching each colored data line to each paper published

    My head is spinning running around in these small social circles.
    Do all roads lead to Mann et al ?

  11. Pat Frank
    Posted Aug 3, 2006 at 7:37 PM | Permalink

    Nos. 7&8 — Kevin, that manuscript was excoriated by the Hockey Team and their supporters as not having been peer-reviewed, and for having used a format similar to that of PNAS. However, Soon, Baliunas, and the two Robinsons published a version of the same analysis in 1999 in the journal “Climate Research. The abstract is here.

  12. Brooks Hurd
    Posted Aug 3, 2006 at 7:43 PM | Permalink

    Re: 10

    Since Wiki climate issues are strongly influenced by RC contributor William M. Connolley, it is hardly surprising that Wiki parrots the RC view of the MWP and LIA.

  13. welikerocks
    Posted Aug 3, 2006 at 7:45 PM | Permalink

    #12 Really?
    He is the guy who said to me “no offense but geologists only study rocks”. Sheesh

  14. Brooks Hurd
    Posted Aug 3, 2006 at 7:45 PM | Permalink

    That was supposed to say: “….parrots the RC view of the MWP and LIA.”

  15. Armand MacMurray
    Posted Aug 3, 2006 at 7:57 PM | Permalink

    A “cartoon” figure is one that is meant to be a qualitative or schematic representation, not an exact representation.

  16. Roger Bell
    Posted Aug 3, 2006 at 7:57 PM | Permalink

    There’s a lot of information about the MWP at
    – even has data showing that New Zealand was affected
    Roger Bell

  17. Steve McIntyre
    Posted Aug 3, 2006 at 8:06 PM | Permalink

    Folks, I’m not canvassing pro-MWP information; I’m canvassing anti-MWP information. Underneath all the armwaving, what actual data underpins the Team’s arguments? Maybe Lee and George B can add to the above list. When you unpack the spaghetti studies, it’s surprising how flimsy they are.

  18. JP
    Posted Aug 3, 2006 at 8:09 PM | Permalink

    We know from historical and proxy records that the LIA and MWP occured over both NAmerica and Europe. What Mann and others are saying is that these events were “local” and did not reflect the entire globe as a whole. That is, for almost 1000 years, a third or more of the world’s climate was either much colder or much warmer than the rest of the world. Is this even physically possible? What we have discovered about teleconnections and the thermohaline circulation is the opposite – that is there are distant connections or signals between hemishperic circulation patterns.

    I do know that this site is really only interested in raw data, but someone in the end must try to model the data into something that physically makes sense.

  19. Brooks Hurd
    Posted Aug 3, 2006 at 8:13 PM | Permalink


    Yes really.

    William told me “No… sorry guv, but you’ve been reading too many the-climate-is-always-changing web sites. Your views are (whether you know it or not) therefore unbalanced on this. Try the wiki GW page….” This was after I had sent him an email asking about the Viking colonization of Greenland. William understands that you can’t have much temperature variation on the shaft of a hockey stick.

  20. JP
    Posted Aug 3, 2006 at 8:45 PM | Permalink

    Supposedly this article by Hughes and Diaz from Science Mag 2004 once and for all destroyed the idea of the MWP. The problem is one must be a paying subscriber to read it. So, truth afterall has a price:


  21. welikerocks
    Posted Aug 3, 2006 at 8:46 PM | Permalink

    #17 “it’s surprising how flimsy they are”
    and the pasta is all stuck together!

    #19 Geez! That’s just creepy.

    I did find an interesting essay when I googled MWP, on this cambridge-conference network here: http://tinyurl.com/qrqgu
    Not con or pro MWP, no proxies, but covers historical tidbits about the “ever changing climate”

  22. Pat Frank
    Posted Aug 3, 2006 at 8:50 PM | Permalink

    #17 — OK, here is the abstract of a 1994 paper by Hughes and Diaz, suggesting from a collection of evidence that the MWP was probably not global.

    SciSearch says the paper has been cited 148 times (a very good number) including 5 citations in 2006 and 17 in 2005. None of the recent 5 are HT members, so far as I could see.

    Of those 5, Steve M., you may be particularly interested in this one (I haven’t access to the full paper, sorry):

    Wang, SW; Luo, Y; Zhao, ZC; Dong, WJ; Yang, B. (2006, Jan) “Debating about the climate warming” PROGRESS IN NATURAL SCIENCE 16, no.1, p.1-6

    Email: swwang@pku.edu.cn

    Abstract: “Debating about the climate warming is reviewed. Discussions have focused on the validity of the temperature reconstruction for the last millennium made by Mann et al. Arguments against and for the reconstruction are introduced. Temperature reconstructions by other authors are examined, including the one carried out by Wang et al. in 1996. It is concluded that: (1) Ability of reproducing temperature variability of time scale less than 10 a is limited, so no sufficient evidence proves that the 1990s was the warmest decade and 1998 was the warmest year over the last millennium. (2) All of the temperature reconstructions by different authors demonstrate the occurrence of the MWP (Medieval Warm Period) and LIA (Little Ice Age) in low frequency band of temperature variations, though the peak in the MWP and trough in LIA varies from one reconstruction to the other. Therefore, terms of MWP and LIA can be used in studies of climate change. (3) The warming from 1975 to 2000 was significant, but we do not know if it was the strongest for the last millennium, which needs to be proved by more evidence.

  23. bender
    Posted Aug 3, 2006 at 8:57 PM | Permalink

    I’m canvassing anti-MWP information. Underneath all the armwaving, what actual data underpins the Team’s arguments?

    The strongest argument they have, IMO, is the idea that the current warming trend is more extenisve around the globe than what is suggested in any of the MWP recons. I believe it is a Briffa paper that makes this argument most convincingly. I have not reviewed it, only remember seeing an abstract. There are significant counterpoints to be made, but this is their side.

  24. Pat Frank
    Posted Aug 3, 2006 at 9:07 PM | Permalink

    #20 — I’ve sent a pdf of that paper to John A to distribute as he sees fit and as copyright law allows.

  25. bender
    Posted Aug 3, 2006 at 9:08 PM | Permalink

    Osborn & Briffa (2006) abstract located

  26. Brooks Hurd
    Posted Aug 3, 2006 at 9:15 PM | Permalink

    Re: 21

    One of the other points that I made to William Connelley was in the same email that caused him to say that my view was “unbalanced”:
    “The Mongol empire began its spread during this same warm period, but faltered when Europe and Asia began to cool. During this same cooling period two successive Mongol invasions of Japan were obliterated by the increased storminess brought on by climate change. The Japanese assumed that the weather was sent from heaven and named the storms kami kaze (ç⦃…¾é⣢¨) or divine wind.”

  27. Brooks Hurd
    Posted Aug 3, 2006 at 9:20 PM | Permalink


    I guess that William Connelley believes that the MWP did not exist because the climate never really changed until the middle of the 19th century. Since he told me that my view was unbalanced, he must therefore be convinced that his view of unchanging climate (no significant MWP) is the “balanced” view of climate change.

  28. Steve McIntyre
    Posted Aug 3, 2006 at 9:34 PM | Permalink

    #22. I’m fully familiar with Hughes and Diaz 1994. It was one of the first papers that I looked at; I’m surprised that I haven’t reviewed it here. It’s junk.

    However, I should probably add in my list of arguments the one from Hughes and Diaz; and this is the viewpoint of Crowley – that the “proxies” in the MWP are a dog’s breakfast and demonstrate regionality. The counterargument is that the “proxies” are junk and that the study cannot be distinguished from cherrypicking from red noise. However, this issue needs to be included in the inventory.

    I didn’t know about Wang; I’ll look at it.

  29. TCO
    Posted Aug 3, 2006 at 9:40 PM | Permalink

    For completeness, I guess it is worth including. However, I think that disproof of an argument for MWP is not the same thing as proof that there was no MWP. Same that your shattering of the hockey stick does not establish that MWP did occur. For all we know Mann have gotten lucky and divined the truth.

  30. John Baltutis
    Posted Aug 3, 2006 at 9:41 PM | Permalink

    Re: #17
    As pointed out by welikerocks, the National Oceanic & Atmospheric Administration has The Story and The Data.

  31. welikerocks
    Posted Aug 3, 2006 at 9:43 PM | Permalink

    I used google scholar and the key words “geology, abstracts, MWP” and found many papers (seem to show this event as global because of all the locations, but different regions reacting in many ways) Saw one that used diatoms in Antarctica here: http://adsabs.harvard.edu/abs/1993PalOc…8..373L

    here’s a link to my search list from google:

    hope that it works

  32. TCO
    Posted Aug 3, 2006 at 9:45 PM | Permalink

    Actually I think Steve’s distillation to what series show the effect is very thoughtful. In essence, they need to show a low MWP AND high RWP to fit his definition of support.

  33. Steve McIntyre
    Posted Aug 3, 2006 at 9:50 PM | Permalink

    Let’s do it this way. This line of discussion derives from the NAS panel. Let’s assume that they did what they could to show that the modern-MWP relationship was "plausible".

    Have I left out any other NAS panel arguments – allowing for my characterization of how the spaghetti studies work.

  34. gbalella
    Posted Aug 3, 2006 at 9:55 PM | Permalink

    Far and away the most significant evidence against a warmer MWP comes from the glacier evidence. From the NAS recent summary Surface Temperature Reconstructions for the Last 2,000 Years (2006) chapter 7 on Glaciers is very convincing.

    As they say, ..”other evidence from glaciers suggests that the recent warmth is unprecedented on millennial time-scales…”

    I suggest anyone who hasn’t read this chapter do so and then provide a reasonable rebuttal as to what better contrary evidence exist to conclude a warmer MWP.

  35. TCO
    Posted Aug 3, 2006 at 10:04 PM | Permalink

    How about that there was insignificant CO2 variation in the past. (if what you care about is AGW, of course, this does nothing since it is circular). But if you JUST care about reconstruction and accept AGW. 🙂

  36. Follow the Money
    Posted Aug 3, 2006 at 10:35 PM | Permalink

    “Underneath all the armwaving, what actual data underpins the Team’s arguments?”

    Steve, I see the armwaving comes from two directions.

    First, the proponents of the hockey sticks selected in the NAS report. Their sticks showed no MWP, or after criticism they messaged the data to show a small one. They are looking to debunk the MWP because it problematizes their research. Therefore they argue the MWP did not exist or was a regional anomaly.

    Second, there is a broader political concern about the MWP – its existence problematizes the selling of carbon-based anthropogenic AGW to the public as a crisis needing quick remedy with the snake oil of carbon credit trading schemes. The politicians and the public are familiar with the MWP, at least here in America, because it is commonly taught in schools. Many people are familiar with it, it comes up in science classes, it comes up in discussions of Shakespeare and Chaucer. Even Al Gore’s movie, so I am told, felt it had to briefly deal with it. Knowledge of the MWP leads to knowledge of natural temperature variability this lessens fear of climate change. The MWP empowers the laity with knowledge with which they can challenge the experts. When presented with the hockey sticks any average politician can reply, “But what about the MWP?” The MWP is powerful not because scientists discuss it, but because the laity believes in it.

    It is interesting that you say the NAS report felt it needed to deal with MWP. A scientist could rationally believe in both the MWP and modern carbon-based anthropogenic AGW. We could be having a cooling period and a rational scientist could also believe he natural cooling is slowed by increased carbon, a little or a lot. But “science” is not the core concern, the debate you find yourself in is not a mere academic exercise. The target audience is the public and the MWP need be delegitimized.

    Knowledge of the MWP goes beyond impeaching hockeysticks. It undermines the sense of fear about climate change. When the public learns about the MWP it is associated with not unpleasant associations such as grape growing in England and Vikings farming in Greenland. No disasters are taught, no one describes the MWP with the shock and awe of an Al Gore slide show, or BP-funded television documentaries. Fear of tipping points, mega-Katrinas, et al. are part of the overarching purpose of selling carbon credit trading schemes and the MWP conflicts with this economic agenda.

    That is one reason the NAS report is troubling. The panel stepped beyond the concerns in science circles into the wider public to help delegitimize, or at least cast doubts, on MWP in order to make Americans more amenable to various legislation. After the rejection of the Kyoto scheme in America the lobbies did not give up on carbon trading schemes in America, evidenced by the recent Waxman bill in Congress. Another example is PM Blair’s recent tentative protocols with the State of California for a carbon trading scheme.

    The “big picture,” seeing the forest for the tree-rings, is the selling of Kyoto-like schemes in America. Does that tell us why an individual diatom study might debunk MWP? No, but it tells us what the motivation is to debunk MWP. Money.

    For clarification, and for example, technological investments called for in Kyoto and Waxman are nice, but need not be linked with a carbon credit trading scheme. One can call for those investments elsewhere and should. I don’t need a phoney story about carbon-based AAGW to know we need to get off foreign energy and reduce pollution. Bush sometimes makes noise about creating a new economy based on hydrogen and increasing efficiencies are nice, but apparently he is waiting for his oil lobby pals to tell him what to do. They will not. The core of the push behind the global warming debate is the carbon credit marketeers. Also there are interests such as British Petroleum who have increased their stakes in natural gas and want a competitive advantage over energy companies more into oil. But carbon credits are the main force.

  37. Allan M.R. MacRae
    Posted Aug 3, 2006 at 11:00 PM | Permalink


    One of the main knocks on the MWP by the hockey team types (remember the film Slapshot – let’s just call them “the Hansen’s”) is that they claim it was a regional, not a global phenomenon. I have not seen the Hansen’s provide good evidence of this. Furthermore, and I may be misunderstanding their point, is it not true that in spite of the current warming (whatever the cause), we have also seen some recent record low temperatures all over the globe? I was in North Africa and London in Feb 2005 and damned near froze. Lately, I understand it has been very cold in parts of the Southern Hemisphere.

    My point is we could also make the (questionable?) argument that the modern warming trend is a regional, not a global phenomenon. It may be simply that we have so much more detailed information now, compared to what we can infer from proxies for the MWP.

    Best, Allan

  38. Jeff Weffer
    Posted Aug 3, 2006 at 11:30 PM | Permalink

    While doing a little searching on the Medieval Warm Period, I ran across a rather interesting little study on Bristle Cones by Tkachuk, 1983 from the upper tree line which VERY clearly shows a MWP and a LIA. I wonder how these tree rings didn’t make it into Mann’s hockey stick.

    “Tree-ring widths vs. time from California Bristle Cone Pine trees. (Source: Tkachuk, 1983)”

    Data charted at:


  39. bender
    Posted Aug 3, 2006 at 11:46 PM | Permalink

    Link to Tkachuck, R.D., 1983, The Little Ice Age, Geoscience Research Institute, is broken. Correct link is here

  40. bender
    Posted Aug 3, 2006 at 11:48 PM | Permalink

    Source data from that Tkachuk (1983) Figure are:

    LaMarche, Jr., V. C. 1974. Paleoclimatic inferences from long tree-ring records. Science 183:1043-1048.

    Hence no post-1974 upward trend in that time-series.

  41. bruce
    Posted Aug 4, 2006 at 12:12 AM | Permalink

    Re: #36:

    Lately, I understand it has been very cold in parts of the Southern Hemisphere.

    Funny you should mention that. I noticed that too, myself. But it doesn’t seem to have been mentioned in the MSM who seem to be obsessed with warming.

    In fact, I noticed it started getting quite cool here some three or four months ago, and it is still quite cold. People are wearing coats, and they have their wood fires on and all. The forecasters are telling us that it will get warmer in a month or two, though. In fact they are anticipating a period of substantial warming through January or February when they say it could get quite hot on some days.

    They seem to think that it is something to do with the sun. But I’m not sure that I can trust them on that. I suspect that it has something to do with rising CO2 levels.

  42. James Lane
    Posted Aug 4, 2006 at 12:15 AM | Permalink

    My point is we could also make the (questionable?) argument that the modern warming trend is a regional, not a global phenomenon. It may be simply that we have so much more detailed information now, compared to what we can infer from proxies for the MWP.

    I’m interested in this point too. As an anecdote, a few years ago I became interested in a journal article by some Australian researchers that contended that recent Australian drought was due to AGW. So I looked up the trend data for as many central Australian sites with temperature records I could find (central Australia being the basis of their analysis) and I couldn’t find any that indicated a rising trend over the 20th century.

    So I emailed the junior author of the study reporting my research, and he replied that he couldn’t tell me the sites used (now there’s a surprise) but that the data was provided by the Australian Bureau of Metereology “so it must be right”.

    (I apologise for not providing citations for all of this, but I lost all these records in a computer crash earlier this year).

    A parallel example is provided over at Realclimate in their critique of Michael Chricton’s “State of Fear” (not a good novel, IMO, but amusing if you’re interested in the AGW debate). Gavin writes:

    Secondly, through the copious use of station weather data, a number of single station records with long term cooling trends are shown. In particular, the characters visit Punta Arenas (at the tip of South America), where (very pleasingly to my host institution) they have the GISTEMP station record posted on the wall which shows a long-term cooling trend (although slight warming since the 1970’s). “There’s your global warming” one of the good guys declares. I have to disagree. Global warming is defined by the global mean surface temperature. It does not imply that the whole globe is warming uniformly (which of course it isn’t). (But that doesn’t stop one character later on (p381) declaring that “..it’s effect is presumably the same everywhere in the world. That’s why it’s called global warming”). Had the characters visited the nearby station of Santa Barbara Cruz Aeropuerto, the poster on the wall would have shown a positive trend. Would that have been proof of global warming? No. Only by amalgamating all of the records we have (after correcting for known problems, such as discussed below) can we have an idea what the regional, hemispheric or global means are doing. That is what is meant by global warming.

    So the question is whether the current warmng is regional or global. It seems to me that Gavin wants to have it both ways: The current warming has regional differences, but globally it’s warming. The MWP has regional differences, but globally it wasn’t warm.

    Given that we have comprehensive instrumental data regarding the modern warming, fine – it’s global (leaving aside arguments about the instrument record). But how can you then turn around and assert that in the MWP (with no instrumental data) it was regionally warm, but globally it wan’t?

  43. muirgeo
    Posted Aug 4, 2006 at 12:33 AM | Permalink

    This is gbalella. Apparently my post aren’t getting through the spam filter.

    Before the HS there was the Lamb graph. If one looks at that the best I can discern is that it shows relatively little variability with a net difference of maybe 1.2C from the MWP to the LIA.

    Note this graph was constructed prior to all the politicalization of climate science.

    My main point is that is the variability of the late Holocene is only of the order of 1.5 C or even it it was 2.0 C over 500 years that will be dwarfed if the projection of 2-3 C of warming over the next 100 years comes true. And note that the recent data supports this projection. Further , I’d claim the best evidence suggest closer to 1.0 C of late Holocene variability….maybe less considering the glacier evidence.

    So I challenge any of you to make a reasonable graph of what you think the last 2,000 years might have looked like ( maybe use Moberg) and then add 100 years to it with 2-3 C increase in temperature. LOOK AT THE GRAPH and just try to imagine its significance if they are actually right. Granted I understand that most of you don’t want to give them their projections but just look at it and imagine if it is right. Can you look at that graph and not be concerned.

    Bottom line is that their projected warming dwarfs almost any known reconstruction of late Holocene variability.

  44. Armand MacMurray
    Posted Aug 4, 2006 at 2:22 AM | Permalink

    Since no one seems to have mentioned this, I’ll toss it in: the folks at RC often seem to dismiss the MWP by claiming that the various temp records/proxies show warming at different time periods (say one peaking at 1100, one peaking at 1000, etc), and thus there was no global synchronous MWP.

  45. Kevin
    Posted Aug 4, 2006 at 4:26 AM | Permalink

    Re #41: Gavin and some other reviewers with vested interests have tried to use this as evidence of Crichton cherry picking. In fact, however, Crichton uses these and other examples very explicitly as evidence that the Warmers are cherry picking. The review is a very transparent and poor effort to discredit the book; while reading the review I couldn’t help but ask myself “Is THIS the best they can do?”

  46. Posted Aug 4, 2006 at 4:52 AM | Permalink

    I agree that the evidence in both ways seems more or less balanced and the answer is uncertain. But whatever the result is, I don’t think that this particular binary question – whether a medieval year in the Middle Ages was warmer than 2006 – can’t have too much impact on policies if they are rationally designed.

    The temperature is primarily evolving in a rather chaotic – or at least hard-to-predict – fashion, and the probability that the earlier among two warm periods was hotter is around 50 percent. Who should really care about it? There are many quantities that are much higher or much lower than their historical values. For example the death rate of various diseases is much lower today. Does it mean that we are entering a dangerous era of global healthening that should be fought with? Maybe, but I don’t want to support such policies.

    Our era is whatever it is, and even if humans influence it, they are influencing it the way they do. It is irrational to connect well-being of a certain industry with the question whether 1350 was warmer than 1998.

  47. Louis Hissink
    Posted Aug 4, 2006 at 5:37 AM | Permalink

    The whole problem with climate change hinges on the unfounded assumption that the earth, in its present celestial orientation, had a constant orientation in 3D space. History argues against this position though these histories are dismissed as fantasies.

    Age old problem of the tools one uses to analyse the data.

  48. McCall
    Posted Aug 4, 2006 at 6:11 AM | Permalink

    In an important example of cherry-picking, MBH excluded Keigwin ’96 Sargasso on the basis Keigwin and Pickart ’99 — therefore K&P’99 qualifies as low-MWP vs 20thC. Of course this Keigwin’99 paper in Science, was published after MBH’99 in AGU — but that only means that the scientists were in contact, prior to publishing?

    For a review of the former with discussion of the latter, see here. In reviewing the info for this thread, I’m now even more suspicious of the MBH exclusion of Keigwin’96 (than just the pub dates) — that is because the K&P’99 reconstruction ended at ~1725. We should know how that Laurentian Fan region is reacting from then to the unprecedented 20thC warming. Perhaps this is answered in Keigwin’05, instead of being accepted as a THC justified exclusion/truncation?

  49. McCall
    Posted Aug 4, 2006 at 6:27 AM | Permalink

    Oops, sorry folks — major goof when I rechecked the paper. Dr Keigwin typically follows the years before present (BP) left-to-right convention. The Laurentian reconstruction started (not ended) ~1725 BP (AD), so ignore #46 para 2 (been staring at too many spaghetti charts, lately)!

  50. McCall
    Posted Aug 4, 2006 at 6:33 AM | Permalink


    Prior Keigwin’9x discussion here:

  51. Steve McIntyre
    Posted Aug 4, 2006 at 6:40 AM | Permalink

    #46. MBH used annually resolved proxies, which Keigwin’s record wasn’t. So, in fairness to them, they had a reason other than simple cherry-picking.

    Lamarche of the 1974 BCP article is also Lamarche of Lamarche et al 1984 (including Graybill, Fritts) which postulated that the BCP growth spurt was due to CO2 fertilization. BTW he was a geologist by training and some of his articles actually include maps of where the samples were taken – something that geologists do. In comparison, Jacoby defended his seeming inability to identify the location of the Gaspe cedars were taken on the grounds that they were sampled before the common use of GPS instruments.

  52. L Nettles
    Posted Aug 4, 2006 at 6:44 AM | Permalink

    re 10, 12, 13, 19 Rocks, welcome to “wikiality”, as defined by that eminent Journalist Stephen Colbert.


  53. Michael Jankowski
    Posted Aug 4, 2006 at 6:58 AM | Permalink

    RE#40, Anecdotal, but what you are talking about – current South Africa winter:

    Temperatures dropped to record lows for August as snow fell in industrial hub Johannesburg for the first time in eight years in what residents say is an unusually severe winter.

    The city saw a high of 7 degrees Celsius (44 Fahrenheit) on Wednesday — the lowest daily high recorded in August — while overnight temperatures dropped well below freezing in some parts of the country. Colder temperatures are expected this weekend.

    RE#41, I got into an argument about Australia in regard to the drought issue over at RC way back when. The Aussie Bureau of Meteorology data and maps suggested in no way a link between late 20th century warming and drought, but I was told that I was wrong because I wasn’t “living there.”

  54. bender
    Posted Aug 4, 2006 at 6:58 AM | Permalink

    #42 and #25 are two sides of the same coin: time vs. space.

  55. McCall
    Posted Aug 4, 2006 at 7:29 AM | Permalink

    re: 49 (re 46)
    Thanks. I’m on the road, and don’t have my pdf lib* on this system; but didn’t Moberg’05 use Keigwin’96 — Moberg’05 did not require annually resolved proxies (with wavelet approach)?

    * have been accessing older pdfs on-line (newer ones less accessible). Couldn’t find Moberg’05 link at http://www.climateaudit.org/?p=345 — will check back later.

  56. Jeff Weffer
    Posted Aug 4, 2006 at 7:49 AM | Permalink

    We know there was a LIA and we know there were significant climate disruptions during “The Dark Ages.”

    It only stands to reason that if these two periods stand-out in terms people being affected by a poor, cooler climate, that in the intervening period, there was a time of better climate and warmer temperatures. Maybe it was warmer in the MWP than today, but it was certainly warmer than the time before and after.

    Unless you build a flat hockey stick and get rid of all the actual climate variability.

  57. Allan M.R. MacRae
    Posted Aug 4, 2006 at 7:59 AM | Permalink

    Re #44 by Lubos:

    Hi Lubos,

    I have enjoyed your comments here and elsewhere but want to understand your words, included below. Since I am not sure exactly what you are saying, I’ll give my own opinion, which you can comment on if you see fit.

    Our era is whatever it is, and even if humans influence it, they are influencing it the way they do. It is irrational to connect well-being of a certain industry with the question whether 1350 was warmer than 1998.

    The fossil fuel industry provides ~87% of global primary energy – the remaining ~13% is hydro and nuclear. I have worked in the energy industry for over half my career. The issue to me is one of human well-being, not the survival of any industry. However I cannot see any viable long-term alternative to fossil fuel except nuclear, either fission or fusion, and this will take considerable time and money to implement.

    Even some informed individuals who accept the questionable projections of catastrophic AGW, like Bjorn Lomborg (Copenhagen Consensus, etc.), believe that there are much better ways to spend the money that is currently devoted to combating global warming.

    I agree with Lomborg, but I further believe that Kyoto and other such CO2-abatement schemes are a massive waste of scarce global resources that should be re-allocated to solve real problems, and not squandered on fictitious ones. I believe the previous sentence summarizes the technical, economic and ethical issue that we are seeking to clarify.

    This may be entirely consistent with what you are saying, or not.

    Best regards, Allan

  58. Greg F
    Posted Aug 4, 2006 at 8:35 AM | Permalink

    … but didn’t Moberg’05 use Keigwin’96 “¢’‚¬? Moberg’05 did not require annually resolved proxies (with wavelet approach)?

    He did a linear interpolation of data that was not annual. The result is he created aliasing which irreversibly corrupted his data.

  59. Richard deSousa
    Posted Aug 4, 2006 at 8:58 AM | Permalink

    Re #18:
    If the warmers claim that the MWP was only a regional occurence because it only affected NAmerica and Europe then why can’t the same argument be applied today since only NAmerica and Europe are warmer but the southern Hemisphere isn’t?

  60. UC
    Posted Aug 4, 2006 at 9:10 AM | Permalink

    Evidence against MWP: The proxies that show MWP are only Local Proxies, they act as thermometers+noise. Then there are Global Proxies that are more accurate than thermometers, they measure Global Temperatures directly+less noise. Such as the ones used in MBH98-99 studies.

  61. Peter Hearnden
    Posted Aug 4, 2006 at 9:14 AM | Permalink

    Re #57 becuase it isn’t that simple ?

  62. muirgeo
    Posted Aug 4, 2006 at 9:39 AM | Permalink

    I guess I’ve been effectively banned as almost 10 post have not come through even after emailing for SPAM clearence issues.

    Eh I consider it a victory.

  63. muirgeo
    Posted Aug 4, 2006 at 9:42 AM | Permalink

    Bottom line is the glacier evidence as summarized in the NAS report is the best evidence against a warmer MWP.

    Take any reconstruction published add 100 years to the x-axis and 2.5 C to the y-axis and then you’ll see the magnitud of the effect of AGW projections which to date are backed by the current surface trends.

    g b a le l la

  64. welikerocks
    Posted Aug 4, 2006 at 10:03 AM | Permalink

    #63 g b a le l la
    No Bottom line.
    The Behavior of World’s Glaciers Fails to Prove Global Warming Theory

    Global warming theory proponents point to the retreat of glaciers in the mid-latitude regions of the planet – areas where the United States, Europe and Africa are located – as evidence of human-induced global warming. As mentioned above, these mid-latitude glaciers cannot be used as reliable indicators of global climate change given that they are affected by a complex mixture of local and regional phenomena. By focusing so much attention on these glaciers, however, one gets the distinct impression that global warming theory proponents are deliberately picking glaciers to analyze that support their thesis that global warming is underway while ignoring those glaciers that don’t support their theory.

    ….There is no indication that the world’s glaciers are melting significantly due to global warming and, thus, there is little to fear from sea level rises in coming decades. Proponents of the global warming theory have been irresponsible in attempting to use glaciers as barometers of global temperatures since glaciers respond to a range of natural phenomena that have nothing to do with global temperature changes. In addition, the advance of the Antarctic and Greenland glaciers, which contain more than 90% of the world’s glacial ice, completely contradicts previous predictions that warming would cause these glaciers to retreat. Far from providing scientific proof of global warming, the behavior of glaciers represents yet another powerful indictment of the already controversial global warming theory.


  65. muirgeo
    Posted Aug 4, 2006 at 10:16 AM | Permalink

    RE 64

    So you are gonna go with the National Center for Public Policy Research of NAS???

    The fact is they and you have got it exactly backwards. The evidence for global warming and climate change is best found in the temperature glaciers that are in relative thermal equilibrium. Meaning that small changes in temperature will be expected to effect their mass balance unlike those frozen glaciers in the extreme environments like Antarctica which will see no change in mass balance even with a few degrees rise in mean temperature.

    The world wide recession of temperate glaciers in light of generally steady or even increased precipitation is clear evidence of ongoing warming and as per NAS the data an glaciers shows anomalous warmth on a millennial time scale.

    What I just said makes sense. What you parroted does not…plane and simple.

  66. muirgeo
    Posted Aug 4, 2006 at 10:17 AM | Permalink

    So you are gonna go with the National Center for Public Policy Research of NAS???

    should be;

    So you are gonna go with the National Center for Public Policy Research over NAS???

  67. beng
    Posted Aug 4, 2006 at 10:26 AM | Permalink

    RE 65:

    The world wide recession of temperate glaciers in light of generally steady or even increased precipitation is clear evidence of ongoing warming and as per NAS the data an glaciers shows anomalous warmth on a millennial time scale.

    Umm, not if the temp 1000 yrs ago was warmer than now. Particularly so if it were 2-3F warmer.

    Muir, almost all 10 kyr proxies show the LIA the coldest global temps in the whole Holocene. You’re not doing a good job of alarmism in the face of these evidences.

  68. Steve Sadlov
    Posted Aug 4, 2006 at 10:45 AM | Permalink

    RE: #9 – Look at the Innuit. It is difficult to imagine a culture like that developing under the current icy regime. I’d imagine it developed during a less icy time.

  69. Michael Jankowski
    Posted Aug 4, 2006 at 10:49 AM | Permalink

    as per NAS the data an glaciers shows anomalous warmth on a millennial time scale.

    Data also shows widespread glacier retreat starting well before the hockey stick blade, and IPCC says what you consider the “anomalous warmth” of the late 20th century somehow hasn’t resulted in an increased rate of retreat.

  70. muirgeo
    Posted Aug 4, 2006 at 10:50 AM | Permalink

    RE 67

    You make no sense. The glacier evidence ITSELF suggest it WAS NOT warmer during the MWP. Glacier that existed through the MWP are now gone. Thousands year old debris are being exposed from receding glaciers NOW because it was not warm enough during the MWP to melt back the glaciers enough to expose them…ect…

  71. muirgeo
    Posted Aug 4, 2006 at 11:15 AM | Permalink

    RE 69

    Wrong! Evidence show INCREASED rate of mass balance loss in the temperate glaciers.

    From the World Glacier Monitoring Service;

    “….The spectacular losses
    in length, area and volume of mountain glaciers during the 20th century are a major reflection of the
    fact that rapid secular change in the energy balance of the earth’s surface is taking place on a global
    scale. The historical beginning of this tendency to rapid secular glacier retreat was probably little
    affected by human activity. The observed evolution may, however, contain an increasing amount
    of anthropogenic influence. The recent shrinking of glaciers now, for the first time, coincides with
    a man-induced climate forcing which could be responsible for a major part of the additional energy
    flux responsible for the observed melt rate. The characteristic value of this melt rate (on average a few decimetres of ice depth lost per year or a few W/m2 for the corresponding exchange in latent heat)
    is broadly consistent with the estimated radiative forcing and changes in sensible heat as calculated
    by numerical climate models. …..

  72. Douglas Hoyt
    Posted Aug 4, 2006 at 11:28 AM | Permalink

    Just consider the Grindelwald glacier in Switzerland. It is larger now than it was in the MWP. History:

    800-1000s: Aletsch and Grindelwald glaciers (Switzerland) were much smaller than today.

    1280: Radiocarbon date on wood (Pinus cembro) of forest buried by advance of Grindelwald glacier; forest does not again grow on site today.

    1588: Grindelwald glacier broke through its end moraine.

    1740s: Glaciers advanced in all Alpine regions, including Chamonix glaciers, Grindelwald and Vernagt glaciers.

    All the above from http://academic.emporia.edu/aberjame/ice/lec19/holocene.htm

    Glaciers have been retreating since about 1750 in most places, long before any increase in carbon dioxide.

    Also see post #9 in this thread. Arctic sea ice is more extensive now than it was in the MWP.

  73. Michael Jankowski
    Posted Aug 4, 2006 at 11:47 AM | Permalink

    Thousands year old debris are being exposed from receding glaciers NOW because it was not warm enough during the MWP to melt back the glaciers enough to expose them

    Or they did melt and were exposed, but nobody really cared or possibly even noticed, then were re-covered and now exposed again.

    Wrong! Evidence show INCREASED rate of mass balance loss in the temperate glaciers.

    You are partly correct – I was wrong with my IPCC statement (got it confused with their sea level rise statement), so I apologize for the error.

    As for your link – it’s starting-off in 1980, which means it’s not taking into account the rates of early and mid 20th century retreats shown here. The mean 2003-2004 balance of -725 mm is less than the standard deviation of 900 mm! If the rest of that data has such issues, it would be statistically invalid to say the rate has changed at all – or that possibly you’re even seeing a retreat from year-to-year.

    And as for your NAS quote:

    “…The historical beginning of this tendency to rapid secular glacier retreat was probably little affected by human activity. The observed evolution may, however, contain an increasing amount of anthropogenic influence. The recent shrinking of glaciers now, for the first time, coincides with a man-induced climate forcing which could be responsible for a major part of the additional energy flux responsible for the observed melt rate…”


  74. JP
    Posted Aug 4, 2006 at 11:52 AM | Permalink

    Below is a link to Brad DeLong’s blog. He tears up M&Ms processes and procedures. Since I am not versed in statistical analysis, I don’t know if he is a quack or what. The following sentence is an example of his critique:

    “M&M failed to compare the spreadsheet to the original data and thus produced a “correction” that was riddled with errors”.

    In any event, it is difficult to find any studies published online or otherwise that refute the MWP and offer hard data. MBH98 is appears to be the best game in town. The others have already been cited. Here’e the link:


  75. Steve McIntyre
    Posted Aug 4, 2006 at 12:10 PM | Permalink

    Let’s reclassify the proxy evidence by proxy type. Let’s try staying away from citing studies where things have been added together and keep focusing on the raw data.

    Treelines: we’ve seen many references to treelines being higher/further north in the MWP than at present. Given the supposedly “regional” nature of MWP, has anyone seen any local evidence anywhere of treelines being higher now than in the MWP? I think it’s very relevant that there’s no obvious evidence of “regional”-ness for this interesting low-frequency proxy. Lamb was very interested in treelines and used treeline changes to estimate past temperature changes.

    Ring width “chronologies”: no need to comment here unless you think that there’s something that I’ve lost track of. There’s the Divergence Factor, various biases, cherry-picking etc. etc. The main innovation of the Team seems to have been divert attention from treeline changes to ring width chronologies.

    Ice core dO18/borehole records. We know the situation in Greenland; Thompson, we’ve discussed; Law Dome we’ve discussed – does anyone know anything else pertinent about Antarctica – like what on earth the NAS panel had in mind in their Antarctica comments?

    Ocean sediments – coldwater diatoms offshore Oman increase in 20th century, a “key” indicator of global warming in Moberg. Sargasso Sea has warm MWP. Keigwin’s Scotia Shelf goes the other way and there’s Mann’s reference to the Pacific to track down. As I recall, Mann uses evidence of coldwater diatoms as evidence of coolness in the Pacific; but Moberg uses evidence of 20th century coldwater diatoms as evidence of warming in the 20th century. Hey, it’s the Hockey Team.

    Glacier retreat – these are barely mentioned in IPCC 1AR and 2AR – I wonder why? The evidence from the Alps – as noted by Doug Hoyt – does not strongly indicate that modern glaciers have retreated past medieval levels. The main argument here seems to be Thompson’s just-published not-even-Reader’s-Digest calibre publication of Quelccaya organics.

    I haven’t posted much on either ocean sediments or glacier retreat.


  76. Steve McIntyre
    Posted Aug 4, 2006 at 12:22 PM | Permalink

    #74. In October 2004, Richard Muller wrote an Op Ed discussing our identification of Mann’s flawed PC method. De Long, Connolley et al said the following:

    Tim L… t and William Connolley think that my colleague Richard Muller has been snookered by McKitrick and McIntyre, who believe that Mann et al.’s data normalizations artificially enhance the influence of series that show an uptrend since 1900. But Connolley argues–I think correctly–that McKitrick and McIntyre are simply confused: the normalizations diminish the influence of series that show a recent uptrend.

    If you’re wondering what the present consensus is as to whether we were "simply confused", you should read the Wegman Report and the NAS Report or listen to their evidence at thehouse E&C Committee. Wegman vindicated the claim ridiculed here by De Long et al; as did the NAS Panel. Both reports carried out simulations which replicated our results.

    The other comment that you quote:

    “M&M failed to compare the spreadsheet to the original data and thus produced a “correction” that was riddled with errors

    is based on disinformation by Mann. For MM03, we asked for the data as used in MBH98 and were eventually referred to a URL at Mann’s FTP site. When we noticed problems in this data set, we sent the data to Mann and asked him to verify that this was the data actually used in MBH. Mann said that he was too busy to answer this or any other question.

    We pointed out many problems with this data, which I’ve discussed in MM03. After MM03, Mann said that the data set at this URL was the wrong data and suddenly a new location materialized and the old data was deleted. Mann said that the "wrong" data was prepared especially for us, but it was dated long before my request. It’s possible that the collation errors made in the "wrong" data were not made in MBH98, but the other problems – including incorrect PC calculation were all correct. I think that the "wrong" data was probably prepared by Rutherford for Rutherford et al 2005 and earlier studies. Amusingly Rutherford et al 2005 says that they didn;t make collation errors in MBH98, and then proceed to incorrectly collate temperature records one year off in Rutherford et al 2005. What a Team!

    Is Delong a quack? I guess that depends on your view of the following:

    Brad DeLong, author of the weblog, “Brad DeLong’s Semi-Daily Journal,” is a professor of economics at the University of California at Berkeley. He is also a research associate of the National Bureau of Economic Research, and was deputy assistant secretary of the U.S. Treasury for economic policy for two years in the Clinton Administration, and is the author of the textbook, Macroeconomics. Born in Boston, MA, on June 24, 1960, Brad received his doctorate from Harvard University, and taught at Harvard, Boston University and MIT.

    To my knowledge, he has not withdrawn his comments made in October 2004 in light of the recent reports.

  77. Michael Jankowski
    Posted Aug 4, 2006 at 12:34 PM | Permalink


    Not sure why you’re bringing this up at this point, all this has been done to death. Briefly:

    Argument 1 – MBH procedure doesn’t preferentially select for hockey sticks: Proven wrong, most recently by NAS statistican Wegman et al.

    Argument 2 – M&M use wrong data (159 columns vs 112): Mann and Rutherford provided f’d data, M&M pointed-out discrepancies, Mann and Rutherford said they’d given them the right info and to leave them alone, then Mann and Rutherford stopped communication. See here for a thorough and amusing description of the happenings.

    Argument 3 – Degress and radians mixed-up by McKitrick elsewhere: as discussed on this site, no more embarassing an error than Mann goofing up cosine vs sqrt(cosine) in MBH98.

    Argument 4&5 – Debated topic that is completely irrelevant to M&M’s papers.

  78. Dave Dardinger
    Posted Aug 4, 2006 at 12:37 PM | Permalink


    “M&M failed to compare the spreadsheet to the original data and thus produced a “correction” that was riddled with errors”.

    Sounds like a rehash of the Mann canard where he turned the fact that he’d had someone send M&M the wrong data into it being their fault. Steve’s talked about this at great length, and will probably come in with a link to the proper discussion. The trick is to compare the timing of what was known when.

  79. Dave Dardinger
    Posted Aug 4, 2006 at 12:43 PM | Permalink

    Dang! I’ve got to start composing of-line and then updating the thread before I post. 15 minutes and I’m already scooped twice!

  80. Steve McIntyre
    Posted Aug 4, 2006 at 1:08 PM | Permalink

    Does anyone know the reference for Mann’s supposedly cool Pacific in the MWP? I recall the matter coming up, but don’t recall in what context. I checked his 2005 article Volcanic and SOlar Forcing etc. , but that only discusses information from models. I couldn’t locate any reference in the NAS report. I’ve been googling without any success.

  81. Ogie Oglethorpe
    Posted Aug 4, 2006 at 2:00 PM | Permalink

    I have to say all the talking of Hockey Sticks, Hanssen brothers, slap stick and “two ‘damned’Canadians”, Tkachuk etc. has me Jonesing for NHL Hockey season. Right up my alley. 🙂

  82. Jim Erlandson
    Posted Aug 4, 2006 at 2:05 PM | Permalink

    re: #80

    Coral reef reveals history of fickle weather in the central Pacific

    The new climate models presented in this paper suggest that while the rest of the world was experiencing certain weather patterns, the Pacific island region and the people who lived there were experiencing something else entirely. During the “Medieval Warm Period” ca. A.D. 900-1200, conditions in the tropical Pacific were cool and possibly dry. Similarly, during the “Little Ice Age” ca. A.D. 1550-1900, the central Pacific was comparatively warm and wet, with stormy conditions more common.

    Melinda Allen. “New ideas about late Holocene climate variability in the central Pacific.” Current Anthropology 47:3.

  83. muirgeo
    Posted Aug 4, 2006 at 2:22 PM | Permalink

    So the evidence is mixed at best. There is no strong suggestion that the MWP and the current period were significantly different. And thus the NAS conclusion to that effect. Thus my point remains (with slight modification) that there are no significant paleoclimate reconstructions or other evidence to suggest more natural climate variability then what we see in the spaghetti graphs. The differences between them are inconsequential when one add 100 years to the x–axis and 2 or 3 C degrees to the y-axis as one will see clearly that if the projections made by the IPCC come to be true then AGW will dwarf natural variability. It won’t even come close to fitting on the standard “spaghetti graph”. In fact, the hockey stick will be flipped with the y-axis now representing the handle and the x-axis representing the blade.

    Nothing of M&M’s work or of all your debate and quibbling here changes these suppositions/facts. Not one significant statistical bit.

    Now what I would like to here some skeptics comment on is how likely do they think…what chance is there….what odds are there that the IPCC is right? And that the ultimate graph 100 years hence will be the one I suggest you draw? 0.1%??…1%??… 5%???…50%??? chance they are right?

    If they are right…looking at the anomalous temperature increases we could be in for does it concern you?…if you knew that was the ultimate graph…would you be concerned enough to suggest that we should indeed take some action?

    I may be a scare monger for looking at the projected graph and gasping. But remember to deny it is to go against a huge number of experts, their data, their refereed articles and their science. I think it takes a lot of cajonays ?sp (OK balls) to assume they have little chance of being right. Especially looking at the current warming trends.

  84. bender
    Posted Aug 4, 2006 at 2:36 PM | Permalink

    there are no significant paleoclimate reconstructions or other evidence to suggest more natural climate variability then what we see in the spaghetti graphs

    1. What makes you think that the spaghetti graphs produced to date are sufficient to represent the full range of possibilities?
    2. Don’t forget, there is an uncertainty envelope around each individual strand of spaghetti. Collectively, the uncertainty envelope is quite wide.
    3. What makes you think the confidence envelopes on each strand of spaghetti aren’t much wider than what is portrayed in the current literature?

  85. Douglas Hoyt
    Posted Aug 4, 2006 at 2:48 PM | Permalink

    New Zealand is near the Pacific Islands mentioned above and apparently had a MWP:


    Wilson, A.T., Hendy, C.H. and Reynolds, C.P. 1979. Short-term climate change and New Zealand temperatures during the last millennium. Nature 279: 315-317.


    Temperatures derived from an 18O/16O profile through a stalagmite found in a New Zealand cave (40.67°S, 172.43°E) revealed the Medieval Warm Period to have occurred between AD 1050 and 1400 and to have been 0.75°C warmer than the Current Warm Period.

    See http://www.co2science.org/scripts/CO2ScienceB2C/data/mwp/studies/l1_nzcave.jsp

  86. Steve McIntyre
    Posted Aug 4, 2006 at 2:57 PM | Permalink

    #83. I’m not sure that the evidence is "mixed at best". For treeline evidence, there seems to be very strong evidence all flowing in one direction.

    The offsetting evidence that I’ve looked at – and I haven’t looked in detail at glaciers and ocean sediments – is unconvincing e.g. bristlecones and cherrypicked ring width chronologies.

    That doesn’t mean that we shouldn’t be concerned about AGW. However, it means that the NAS panel failed to properly survey the evidence on the medieval-modern difference.

  87. Peter Hearnden
    Posted Aug 4, 2006 at 3:03 PM | Permalink

    Steve, if the evidence is strong we could see it as a reconstruction. So why haven’t we? Well, I think it’s because the evidence for a globally or hemispherically strong MWP isn’t strong. Or, are you going to produce a recon?

  88. TCO
    Posted Aug 4, 2006 at 3:07 PM | Permalink

    To what extent should we think of the strands of spaghetti as different measurement attempts that can be merged together to get a better picture of the whole (as say with polling subsamples)? To what extent should we compare the differences in the strands and indict the overall measurement technique (as if we had wildly varying polls…not only would this indicate that we didn’t know the true population, but would indicate we are doing some crappy or differentially skewed polling). To what extent are they non-independant?

  89. bender
    Posted Aug 4, 2006 at 3:12 PM | Permalink

    Peter, we already know what you think, because your Belief has been stated here many times. But you ask a fair question. One thing I know: you don’t necessarily need new & better data to get a better reconstruction. You could just use a more honest method of reconstruction.

  90. Mark T.
    Posted Aug 4, 2006 at 3:26 PM | Permalink

    Steve, if the evidence is strong we could see it as a reconstruction. So why haven’t we? Well, I think it’s because the evidence for a globally or hemispherically strong MWP isn’t strong. Or, are you going to produce a recon?

    Logical fallacy. You’re assuming that if there is evidence/proof for a strong MWP, a reconstruction should be made to show that, and in its absence, your concept of a weak MWP is thusly proven. Absence of proof is not proof of the contrary. This is particularly notable in this instance where we have the so-called proof of a weak MWP (the HS) completely discredited.

    Of course, “belief” belies logic.


  91. TCO
    Posted Aug 4, 2006 at 3:31 PM | Permalink

    If the bristlecones are really so evil and prone to error (more so then other trees) we oguht to have a full length paper to discuss this. The little bit in EE, the snippets on the site and the unsupported (and paradoxical) assertion in NAS are not sufficient to really think about this.

    On the cherrypicking, I think there are different kinds:
    1. biased selection to get a story (Polar Urals, blabla)
    2. reversion to the mean fallacy: let’s say that they are all basically crappy proxies, so when we pick those few that show recent warming, it’s not a surprise that in early (or future) eras, they don’t show anything special. It’s like betting red on the particular wheel that had 4 reds in a row at Las Vegas!
    3. Geographic or other incorrect emphases in how subsamples are combined (too much from NA for instance).

    I would really like to see a more robust consideration of the literature then the one-off cherry-pick comments on CA. For instance, let’s say Polar Urals was misdated. How many other HS-promoting series were examined and found not wanting? If we examined non-HS promoting series, could we find some errors that would drive them to BE HS promoting?! (IOW, is “cherrypicking” itself being “cherrypicked”?) Now, I know there are limits to Steve’s time. And I think he’s a free agent and should work on whatever floats his boat (even though it might be more slanted than an objective review…and I realize that it also may be more effective/efficient as well to study problem children particularly!) And it is great to see his individual analyses of possible problems in particular areas. Would be even more additive if he published them. But to me, those are just data points. We still need to stand back and see how the overall results were changed and even need to think about if an individual might be skewing the meta-analysis by finding the problems only with outliers on the “top half” of the scatterplot.

  92. bender
    Posted Aug 4, 2006 at 3:31 PM | Permalink

    Re #88

    To what extent should we think of the strands of spaghetti as different measurement attempts that can be merged together to get a better picture of the whole (as say with polling subsamples)?


    To what extent should we compare the differences in the strands and indict the overall measurement technique (as if we had wildly varying polls…not only would this indicate that we didn’t know the true population, but would indicate we are doing some crappy or differentially skewed polling).


    To what extent are they non-independant?

    Irrelevant. You don’t need independence to figure out what the highest upper limit and lowest lower limit on the collection of spaghetti strands is, or to make the inference that the truth lies somewhere in between.

  93. bender
    Posted Aug 4, 2006 at 3:33 PM | Permalink

    Re #91
    You want all this in one paper? Won’t happen. There are alot of bricks in that building.

  94. Cameron
    Posted Aug 4, 2006 at 3:34 PM | Permalink

    Doug – here is the study I was talking about…

    New Zealand is a long way from the tropical pacific – its where I’m from. Also your paper was 27 years old which is basically the time of most dramatic recorded warming…

  95. charles
    Posted Aug 4, 2006 at 3:41 PM | Permalink

    #83 muirgeo

    Since warming due to CO2 is a log function there is no reason to believe warming for the next 100 yrs should be greater than the 0.6dc we have seen the last 100yrs. Whats more, there is no reason to believe additional modest warming will not be a net plus just like it has been the last 100yrs.

    These basic facts allow me to sleep well at night. I do see a silver lining in all the negative hype by warmers. Nuclear power is poised to be taken off the shelf and more fully utilized in the future. The average citizen is going to pick nuclear rather than make dramatic cutbacks in energy use.

    So keep up the negative hype. It is warming the public to nuclear.

  96. Peter Hearnden
    Posted Aug 4, 2006 at 3:43 PM | Permalink

    R #90, nope, the word was ‘could’ not ‘should’. I’d also say that, in the absense of supporting evidence like a recon, the notion of a globally strong MWP isn’t proven. Finally I think evidence for large magnitude global/hemispheric temperature changes would be more evident that that for small magnitude. So, if there was a large magnitude MWP is should be more obvious than a small magnitude one, and a recon could be made. But, I tell you this, we WILL NOT see a sceptic recon – EVER. Draw your own conclusions…

  97. bender
    Posted Aug 4, 2006 at 3:48 PM | Permalink

    Maybe we oughta produce and publish an honest BCP recon? Peter sounds so certain of his many Beliefs.

  98. Peter Hearnden
    Posted Aug 4, 2006 at 3:53 PM | Permalink


    Since warming due to CO2 is a log function there is no reason to believe warming for the next 100 yrs should be greater than the 0.6dc we have seen the last 100.

    How can the oceans of a planet 70% plus ocean respond instantainously to warming? Answer: they can’t. There is a lag of at least decades between emission and warming. Makes you think? I doubt it…

  99. welikerocks
    Posted Aug 4, 2006 at 3:53 PM | Permalink

    It’s mind boggling to me that a widely accepted time in history that was warmer then the people living in it ever experienced and noted so by these fellow humans in various ways is argued over by fractions of C with a hockey stick graph as it’s main point; which is flawed and created with a obvious agenda in mind.

    Not to mention the timescales, earth age and huge error bars using any type of proxies to represent temperature by fractions!

    AND Not to mention, nobody argued over it all that much until the hockey stick and the IPCC wanted to make it all go away.

    Not to mention that “climate science” : satellites, computers and the needed technology are only what? 40 yrs old if that much? (How old is Mann anyway?)

    And every day we are told “Its never been hotter!

  100. TCO
    Posted Aug 4, 2006 at 3:56 PM | Permalink

    “Irrelevant. You don’t need independence to figure out what the highest upper limit and lowest lower limit on the collection of spaghetti strands is, or to make the inference that the truth lies somewhere in between.”

    Could you expand on that? Intuitively if I do 4 seperate polling tests and combine the data (and they are independant) then my error bars will be lower then if I had significant overlap among the subsamples.

  101. TCO
    Posted Aug 4, 2006 at 4:03 PM | Permalink

    93 (too much): yes, I agree that this is a lot of work. Even getting tiny little analyses finished and published would be an improvement over the current Wegman-indicted blogging scholarship. But when they are done they should be published without overdramatic claims on significance given that we haven’t done the more in depth overview. I think it’s ok (and suitable) to discuss POSSIBLE RELEVANCE to the larger questions that result from throwing out misdated Polar Urals for instance. I would write the paper, mostly on the dating issue itself. Then include a bit about the possible impact on other things with enough explication to show how the revision might be interesting/might impact things. But with some weasel words and caveats (since we have not subjected all the components of the larger reconstruction to the same penetrating scrutiny).

  102. bender
    Posted Aug 4, 2006 at 4:03 PM | Permalink

    Re #98
    And the oceans’ dynamics, Peter, do you think they’re adequately represented in the forcing models used to estimate CO2 sensitivity coefficients? Fluid dynamics, water vapour, clouds, and all? Or would you say those models are somewhat simplified?

  103. Peter Hearnden
    Posted Aug 4, 2006 at 4:03 PM | Permalink

    Re #97. Humm, with #90 the second to accuse me of ‘belief’ in recent posts. What are you two trying to say by the use of that word? Not, no you can’t be, you’re not trying to imply I’m somehow religious in my belief? No, two people so firmly anti logical fallacy as you to stooping to ad hom? nah…

    Go on, publish I say. But, I KNOW you wont. There isn’t going to be a sceptic recon – EVER!

  104. muirgeo
    Posted Aug 4, 2006 at 4:04 PM | Permalink

    Re# 84

    1. What makes you think that the spaghetti graphs produced to date are sufficient to represent the full range of possibilities?

    Comment by bender “¢’‚¬?

    Well as soon as Steve publishes his reconstructions based on tree line data, that excludes the possibilies of genetic variation and drift, then will have one less “possibility”.

    Seriously, why do you think some data will suddenly become apparent that reveals the MWP 2 or 3 C warmer then present. What’s that Occum laws? I think the general preponsderance of data is telling us Mann if wrong was not that far off. MWP= current Period +/- 0.5 C.

  105. Peter Hearnden
    Posted Aug 4, 2006 at 4:05 PM | Permalink

    #102 Perfect? No. They might over OR under estimate. Wrong? No, not perfect, yes.

  106. charles
    Posted Aug 4, 2006 at 4:06 PM | Permalink


    Peter, most of the warming of the last 100yrs occured in the first half of the century, before the big rise in CO2. Hard to see a CO2 rise, ocean lag, temp rise there.

    Keep it up. Nuclear is coming back. Back to where it should have been before it was demonized by the same people demonizing CO2 today.

    I do regret spending $2B/yr on climate science. Seems to me $100M/yr maintaining earth and satellite temp stations should be enough.

  107. Peter Hearnden
    Posted Aug 4, 2006 at 4:09 PM | Permalink

    Re #99

    It’s mind boggling to me that a widely accepted time in history that was warmer then the people living in it ever experienced and noted so by these fellow humans in various ways is argued over by fractions of C with a hockey stick graph as it’s main point; which is flawed and created with a obvious agenda in mind.

    OK, YOU publish a recon then 😉 .Go on, you’ve clearly got the data – DO IT! You wont, none of you sceptic will. I say again, there IS NOT going to be a sceptic recon – EVER.

  108. Peter Hearnden
    Posted Aug 4, 2006 at 4:11 PM | Permalink

    Re #106

    Peter, most of the warming of the last 100yrs occured in the first half of the century, before the big rise in CO2.

    No it did not, not most.

  109. bender
    Posted Aug 4, 2006 at 4:12 PM | Permalink

    RE #100
    Error propagates. Data are the cure for error.

    In your example you are talking about the effect of additional data. In my example I am talking about the effect of additional uncertainty. It’s more than apples vs oranges. It’s matter vs anti-matter.

  110. Douglas Hoyt
    Posted Aug 4, 2006 at 4:19 PM | Permalink

    Cameron, I can’t access your article.
    Here is another article for South America showing a MWP:

    Climatic Change
    Publisher: Springer Netherlands
    ISSN: 0165-0009 (Paper) 1573-1480 (Online)
    DOI: 10.1007/BF01092413
    Issue: Volume 26, Numbers 2-3

    Date: March 1994
    Pages: 183 – 197
    Tree-ring and glacial evidence for the medieval warm epoch and the little ice age in southern South America
    Ricardo Villalba1, 2

    (1) Department of Geography, University of Colorado, 80309-260 Boulder, CO, USA
    (2) Present address: Laboratorio de Dendrocronologia, CRICYT – CONICET, Casilla de Correo 330, 5500 Mendoza, Argentina

    Received: 22 September 1992 Revised: 27 October 1993

    Abstract A tree-ring reconstruction of summer temperatures from northern Patagonia shows distinct episodes of higher and lower temperature during the last 1000 yr. The first cold interval was from A.D. 900 to 1070, which was followed by a warm period A.D. 1080 to 1250 (approximately coincident with theMedieval Warm Epoch). Afterwards a long, cold-moist interval followed from A.D. 1270 to 1660, peaking around 1340 and 1640 (contemporaneously with earlyLittle Ice Age events in the Northern Hemisphere). In central Chile, winter rainfall variations were reconstructed using tree rings back to the year A.D. 1220. From A.D. 1220 to 1280, and from A.D. 1450 to 1550, rainfall was above the long-term mean. Droughts apparently occurred between A.D. 1280 and 1450, from 1570 to 1650, and from 1770 to 1820. In northern Patagonia, radiocarbon dates and tree-ring dates record two major glacial advances in the A.D. 1270–1380 and 1520–1670 intervals. In southern Patagonia, the initiation of theLittle Ice Age appears to have been around A.D. 1300, and the culmination of glacial advances between the late 17th to the early 19th centuries.
    Most of the reconstructed winter-dry periods in central Chile are synchronous with cold summers in northern Patagonia, resembling the present regional patterns associated with the El Niño-Southern Oscillation (ENSO). The years A.D. 1468–69 represent, in both temperature and precipitation reconstructions from treerings, the largest departures during the last 1000 yr. A very strong ENSO event was probably responsible for these extreme deviations. Tree-ring analysis also indicates that the association between a weaker southeastern Pacific subtropical anticyclone and the occurence of El Niño events has been stable over the last four centuries, although some anomalous cases are recognized.

    End quote.
    New Zealand and South America are far away from Europe and the Arctic Ocean.

    And here in the western tropical Pacific (see http://earth.usc.edu/~stott/ProjectsFolder/ProjectsII.htm), the MWP shows up yet again. See the figure at http://earth.usc.edu/~stott/public_html/PNG%20figures/Mideaval%20warm%20period.png

  111. bruce
    Posted Aug 4, 2006 at 4:21 PM | Permalink

    re #103: From Encarta Dictionary

    ‘be·lief [ bi lïŸ⻦ ] (plural be·liefs), noun


    1. acceptance of truth of something: acceptance by the mind that something is true or real, often underpinned by an emotional or spiritual sense of certainty
    belief in an afterlife

    2. trust: confidence that somebody or something is good or will be effective
    belief in democracy

    3. something that somebody believes in: a statement, principle, or doctrine that a person or group accepts as true

    4. opinion: an opinion, especially a firm and considered one

    5. religious faith: faith in God or in a religion’s gods

    [12th century. Alteration of Old English gelÄ“afa after believe] “

  112. welikerocks
    Posted Aug 4, 2006 at 4:24 PM | Permalink

    #107 There’s hundreds of papers and text books that mention the MWP and LIA as widely accepted. You don’t read them, or see them or give them any credit because you believe the HS and in your cause.

    How many of them were rejected in the last 8 years or so because your peers wouldn’t let them be published? As in: “there IS NOT going to be a sceptic recon – EVER. ” Hmmm?

  113. Cameron
    Posted Aug 4, 2006 at 4:28 PM | Permalink

    Doug – It might be subscription…the ref was mentioned earlier it was:

    Current Anthropology Volume 47, Number 3, June 2006

  114. bender
    Posted Aug 4, 2006 at 4:33 PM | Permalink

    Re #107
    Peter, read Burger & Cubasch 2005 & 2006, who have done some recon work. Let me quote two lines:

    “Any robust, regression-based method of deriving past climatic variations from proxies is inherently trapped by variations at the training stage.”

    “Are 25% RE enough to decide the millenial NHT controversy? This is the crucial question. 25% RE translates to an amplitude error of ~85%. If one were to focus the controversy onto the single question: “Was there a MWP and was it possibly warmer than recent decades?” – we doubt that question can be decided based on current reconstructions alone.

    They sound skeptical. They’ve done recon. These studies are the most rigorous I’ve ever seen. What are you wailing about?

    More importantly, what do you make of their conclusions?

  115. TCO
    Posted Aug 4, 2006 at 4:37 PM | Permalink

    110, one thing that I wonder about (sorta new idea at least for me!) is the statement from the NAS that their was evidence for MWP’s but that they occurrend at different times (thus going against the idea of a general warming of the earth as a whole. But I wonder, if you combine those regional MWP’s (even though they are not coincident), to you get an overall MWP still? I mean Mann combines records to get flattness, if we combine records showing MWP 800-1000 and 1000-1200 and 1100-1300 and 800-900 and 1200-1400 and so on and so on (and of differing amounts and such) and still come up with some MWP centered at 1100 or whatever with a prominent bulge is that less helpful then Mann’s combination which shows flatness (but has bumpiness in individual proxies). Of course if we combine all those MWP-promoting (but differing in date by region) records and get a flat line…well heck. That supports Mike. And we publish that. Whatever is, is!

  116. Steve McIntyre
    Posted Aug 4, 2006 at 4:46 PM | Permalink

    #115. The NAS panel was relying on Crowley and Hughes/Diaz for these statements. They didn’t do any due diligence on them and so these statements of theirs are worth no more than the original assertion by Crowley, whose work is junk. That’s the trouble with doing this sort of fly-in fly-out panel.

  117. TCO
    Posted Aug 4, 2006 at 4:56 PM | Permalink

    109: Ok. but you were replying to my post. I think you even quoted it. Also (getting beyond the argument about what each of us is arguing about), to the extent that the studies are dependant but treated as independant, this will exaggerate the believed amount of data. (Of course if we explicitly combine their inputs and eliminate duplicates, the additive benefit of the extra data will be extracted.) But if we don’t, then we won’t. And a lot of the casual discussion, does not.

    114: I read the comment you are talking about from Burger and Cubash. I would like a deeper explanation of the point in order to evaluate it. Also, I found it flawed in how they did not flesh out the issue and how they stated new analysis within the conclusion. Most reviewers and commentators have agreed with this view of poor explication (not showing the algebra, not articulating the whole argument). Burger and Cubash have done the same as well. Have even said that they made the paper overly cursory because of GRL limits (those showing the many, classical, complaints about inadequacy of letter papers) and also showing that people tend to be lazy when going to online publications since CPD did not have the GRL space limit!

  118. Ken Fritsch
    Posted Aug 4, 2006 at 5:10 PM | Permalink

    re: #86

    That doesn’t mean that we shouldn’t be concerned about AGW. However, it means that the NAS panel failed to properly survey the evidence on the medieval-modern difference.

    Steve M, it appears to me that NAS was defending AGW, as I noted previously, by way of the process that a lawyer would in making a case with much circumstantial evidence none of it by itself very strong. I find that their approach was very defensive of AGW, primarily because I thought their main mission was to look more specifically at the HS and the validity of its derivation. That in itself to me indicates that the importance of the HS to the circumstantial evidence for AGW was originally oversold. Much can also be implied for the AGW case from that overselling (of the HS) in my estimation. The case of the opposition, whether that is in part as you have confined your observations/criticisms of their report or a more general one, is missing.

    I have strong reservations on making the general case against AGW for the same reasons as I see what NAS did in making the case for. I think what you are doing avoids that by simply looking in more detail at the evidence for and against and letting the chips (and public policy) fall where it may. It would be great to see some links to what has been discussed at CA previously as you noted in this blog article and references to specific and relevant parts of those links.

    I remain convinced that a few people come to your blog to become indignant and that they will regardless of what is presented. I am hoping that I can continue to learn from your blog articles and discussion of them and that the noises of indignations and replies to them are drowned out by those discussions.

  119. TCO
    Posted Aug 4, 2006 at 5:11 PM | Permalink

    Steve (116): Yes, I agree, this is a limitation of this sort of panel. Fortunately there is this thing called a “science paper”. 🙂

    I could have told you about the problems associated with Filipina hookers. Now that you’ve had your fling, go back to the good woman. 🙂

  120. KevinUK
    Posted Aug 4, 2006 at 5:14 PM | Permalink

    #57 Allan, I like your posts very much. They make a lot of sense to me but

    “However I cannot see any viable long-term alternative to fossil fuel except nuclear, either fission or fusion, and this will take considerable time and money to implement.”

    Commercial scale generation of electricity from fusion is a myth – it will IMO never happen not in my lfetime or any of my five kids lifetimes. Dare I say it, it is an even bigger myth than AGW. As a technology is an order of magnitude less proven than even solar or wind turbine technology. The eco-theologions of course love it, because it is ‘less polluting’ and of course is based on that unlimited ‘harmless’ non-polluting resource (but dominant GHG water). Please don’t even mention it in the same sentence as fission. In Canada your have an excellent REAL nuclear (fission) technology – CANDU. You need fusion power generation technology, like you need a hole in the head. You already have the most demonstrably successful nuclear power generation in the world – you do not need fusion. You also have less of an obsession to reprocess spent nuclear fuel which is a good as it its the reprocessing of the spent fuel to recover the plutonium that has ruined the economics and long term viability of nuclear power generation IMO. It was the so called euphemistically named ‘plutonium credit’ that wa suse din the past to justfy the costs of nuclear power generation in the past. This wold have mad esense if a) we atually built some fast reactors to burn this plutonium b) actually designed the few that where actually built so that they had a positive breeder coefficient but WE DIDN’T. I culd go on more but I think thats enough of a rant.

    #95 Charles

    “I do see a silver lining in all the negative hype by warmers. Nuclear power is poised to be taken off the shelf and more fully utilized in the future. The average citizen is going to pick nuclear rather than make dramatic cutbacks in energy use.”

    I personally will be extemely disappointed if the rebirth of nuclear power generation is based on lies (i.e AGW) as it was originally. Th epublic n the UK at lest was sold on the idea that nuclear power was cheap. so cheap that it wouldn’t even need to be metered. This was a LIE. The early designs of nuclear power plant in the UK where designed and operated so that they could breed plutonium. In the UK, many (who are still in the nuclear industry) continue to deny that this was the case. We continue to reprocess spent fuel to extract the plutonium. Why? If the plutonium were to actually be re-used as a nuclear fuel then this might perhaps make sense but it isn’t. No fast reactor and No mixed-oxide (uranium and plutonium oxide) fuel fission reactors. Reprocessing spent fuel multiplie sup the volume of contaminated nuclear waste and facties that need to be decomiisioned by at least an order of magnitude so it really makes no sense whatsoever. Tony B (the biggest liar in the UK) thinks that we must have more nuclear power generation plant inorder to mitigate another falsehood (AGW). No No! No! If we are to have more nuclear generation in te UK then the lying and deception must stop. The legacy of the previous cold war inspired nuclear programme must be dealt with and the distortion (because of reprocessing) of the economics of nuclear generation must stop. Only then will nuclear power play it’s intended role in man’s future development. End of second rant.

    Steve sorry this is off thread but I thought it had to be said given that the reason d’etre of this blog is exposing the truth behind AGW.


  121. TCO
    Posted Aug 4, 2006 at 5:17 PM | Permalink

    118: Great post and for once, I’m in complete agreement with you. I think the problem is a bit that Steve himself has got so caught up in the AGW side issues (or always was) that he’s not really interested in just “finding things out and letting chips fall”. Oh…that and not publishing…and sometimes confounding issues in debate or analysis. (But he is frigging smart and has done a great service for us regardless.)

  122. TCO
    Posted Aug 4, 2006 at 5:19 PM | Permalink


  123. Ken Fritsch
    Posted Aug 4, 2006 at 5:35 PM | Permalink

    re: #115

    And we publish that. Whatever is, is!

    TCO, who is we?

    You are not really serious with this post are you? I thought your position was closer to that which bender stated in #114.

    re: #117

    But if we don’t, then we won’t. And a lot of the casual discussion, does not.

    TCO, this read better after I started on my second martini. I’ll bet Yogi wished he had said that.

  124. TCO
    Posted Aug 4, 2006 at 5:36 PM | Permalink

    Let me go get some gin and chat a bit with you. OK?

  125. John Creighton
    Posted Aug 4, 2006 at 5:38 PM | Permalink

    #120 so you are saying that because power plants are built with military rather then commercial applications in mind the economics are ruined. Interesting.

  126. TCO
    Posted Aug 4, 2006 at 5:39 PM | Permalink

    Is “one” better than “we”? And you really should have just used the Lone Ranger joke!

  127. KevinUK
    Posted Aug 4, 2006 at 5:39 PM | Permalink

    That should be Chernobyl TCO

    I dont think Steve wants a debate on how not to design and operate a nuclear power plant on this blog. I think it might be OK to discuss nuclear power in the context of AGW but not nuclear safety. My post was to illustrate that nuclear power is not (as your minimal post I think implys) an enviromental panacea.


  128. TCO
    Posted Aug 4, 2006 at 5:43 PM | Permalink

    Steve isn’t watching so we could playfully misbehave and just talk nookie pookie if you want to…

  129. KevinUK
    Posted Aug 4, 2006 at 5:50 PM | Permalink

    #125 JC

    I’d love to expand on this but I really don’t think that Steve wants a debate on the whys and wherefores of nuclear power generation and its historic legacy on this blog.


  130. KevinUK
    Posted Aug 4, 2006 at 5:58 PM | Permalink

    TCO, I love your posts.

    What is ‘nookie pookie’ LOL.


  131. TCO
    Posted Aug 4, 2006 at 5:58 PM | Permalink

    The US has had a serious reactor accident as well. Smaller version of Chernobyl.

  132. KevinUK
    Posted Aug 4, 2006 at 6:14 PM | Permalink


    I think I’ve just twigged what ‘nookie pookie’ is? its nuclear power isn’t it. Its a bit late here in the UK and I’m tire dso it took a minute ot two to work it out. At first I thight it meant something a bit more ‘blue’ which i’m sure Steve definitely doedn’t want discussing on this blog.

    You really can’t and shouldn’t compare Three Mile Island with Chernobyl. Much as the operators made mistakes at TMI (they didn’t believe what the instrumentation was telling them (actually the warmers will say there is a parallel with AGW denial here). They didn’t in effect pull out all the control rods on a flawed reactor system (RBMK) that had a positive void cover coefficient. They didn’t cover up (more possible AGW parallels here) the accident and as a result the local population wasn’t evacuated until 48 hrs later. The recator lid didn’t blow of the top of the reactor at TMI and there weren’t any molten fuel/coolant interactions at TMI as there were at Chernobyl.


  133. TCO
    Posted Aug 4, 2006 at 6:17 PM | Permalink

    I mean SL-1 where we did blow off the lid (exploded the vessel, sent fuel out of the containment). Much smaller core and only a few killed. But definitely a legitimate nuclear accident (not incident).

  134. bender
    Posted Aug 4, 2006 at 6:17 PM | Permalink

    Get a motel room!

  135. TCO
    Posted Aug 4, 2006 at 6:19 PM | Permalink

    You were making me jealous with that DanO liaison. I’ll have time for you later, honey!

  136. KevinUK
    Posted Aug 4, 2006 at 6:20 PM | Permalink


    Please – TCO and I are not that way inclined.


  137. KevinUK
    Posted Aug 4, 2006 at 6:24 PM | Permalink

    Actually I’ve just realised that TCO could well be female (I’m male). Even if so, I’m not quite ready for a divorce just yet.

  138. KevinUK
    Posted Aug 4, 2006 at 6:28 PM | Permalink


    When making such statements in the UK we are advised by our lawyers to prefix them with the word ‘allegedly’. You never know who is reading this blog.


  139. TCO
    Posted Aug 4, 2006 at 6:52 PM | Permalink

    Yeah, but we’re independant now. 🙂

  140. JP
    Posted Aug 4, 2006 at 8:36 PM | Permalink

    “So the evidence is mixed at best. There is no strong suggestion that the MWP and the current period were significantly different.”

    Either Mann is correct, or his own reconstruction is seriously flawed, and there has been plenty of climate variability prior to the 20th Century. Mann’s reconstruction showed absolutley little global variability until the 20th century. All past reconstructions which showed obvious variabilities in the form of the MWP and LIA were relegated to just “local” conditions (local being large slices of the globe). Mann, in effect said. “I am right, and past reconstructions were right if only if relegated to certain geographical areas.” He never said it wasn’t very hot in Europe and N.America during the MWP, and very cold during the LIA; he just relegated them to regional variations based on teleconnections and local conditions.

    Either large slices of our atmosphere were behaving with “extreme variability” in relation to the rest of the global climate, or Mann is wrong. If I read Mann correctly, North America, Europe and the North Atlanitc were radically warmer during the MWP, and radically colder during the LIA when compared to the remainder of the globe. . Otherwise, the MWP and LIA were a figment of historical imagination.

    If the MWP did occur with as much warming as today, what caused it?

  141. mark
    Posted Aug 4, 2006 at 9:39 PM | Permalink

    The sun.


  142. MarkR
    Posted Aug 4, 2006 at 9:50 PM | Permalink

    Quite a good read from Ireland. Apparently they have oak trees preserved for 7000 years in peat bogs. They think yhe Dark Ages may have been the result of Comets. If true it certainly sounds like a very good tree ring record.

    “What happened was that in analysing this 7000 year chronology it became clear that there were a number of very notable growth downturns, where a whole series of long-lived Irish oak trees showed their narrowest growth rings at exactly the same time, and this stood out at roughly one every 1000 years. And the one that interested me most because it falls in the historic period, is the one at 540AD and I thought well at least at 540 there should be some historical records to give me a hand to understand this event.

    “However as dendrochronologists go further back in time they discover that there is a different class of event. The first event of this kind occurs in the immediate vicinity of AD 540. Around that time several tree-ring chronologies from places as dispersed as Siberia, Fennoscandia, Northern Europe, Western North America and Southern South America all show notable growth downturns at the same time. “This is highly unusual” says Baillie. Just how unusual it is can be conveyed by the fact that these chronologies quantify the 540 event as ‘the worst’ or the ‘second worst’ or ‘one of the four worst’ events in the last 1500 years. There is no other equivalent event in the last 1500 years.”

    Geology News

    From Turkey

    “Carol Griggs has being doing a survey of oak tree-growth over the last millennium. Her graph shows raw ring-width measurements from over 500 oak samples which she averaged to find out when major regional climate changes might have occurred. Several of the anomalies appear to be contemporary with well-known deviations like the Medieval Warm Period or the Little Ice Age. One thing that the tree-rings tell us is that the present global warming is no warmer than the Medieval Warm Period. This kind of major fluctuation is present in many of the long tree-ring chronologies, and Mike Baillie’s paper on this subject in the next issue of Dendrochronologia should be well worth reading.”

    Aegean Dendrochronology Project December 2001 Progress Report

  143. Allan M.R. MacRae
    Posted Aug 4, 2006 at 9:57 PM | Permalink

    RE #120 from Kevin UK:

    Hi Kevin,

    I understand that you did not like my comment, as follows, because you quite rightly state that fusion power is not close to being a reality, and is unlikely to be so for many decades to come:

    “However I cannot see any viable long-term alternative to fossil fuel except nuclear, either fission or fusion, and this will take considerable time and money to implement


    I am of the same opinion as you about fusion. However, let’s put my comment in context. It will also take many decades for fossil fuels to be displaced as the main energy source for our civilization, whether the incentives are AGW-driven or purely economic (with no bogus AGW incentives). As I said earlier, fossil fuels account for ~87% of global primary energy, and to significantly change this fact will be an undertaking of unprecedented global scope. By the time this happens, you and I will be long dead, and fusion power could be alive and well.

    Best, Allan

  144. MarkR
    Posted Aug 4, 2006 at 10:17 PM | Permalink

    One of Carol’s poster presentations is enclosed with this newsletter. It is a climate reconstruction for the North Aegean back to 1169 based on 517 oak tree-ring sequences from 46 sites in Greece and Turkey.

    If this long chronology holds together, and we expect that it should, we will have an ‘Iron Age Gap’ rather than a ‘Roman Gap,’ and our task will be to try to link this 26-century oak sequence with our 2009-year conifer sequence somewhere in the middle of the second millennium BC. We also have 40-odd conifer chronologies with which we will try to replicate the 6th century BC-to-present oak chronology this coming semester. You will get a report on all of this at the end of 2006 or whenever we make the breakthrough, whichever is sooner.


  145. gbalella
    Posted Aug 4, 2006 at 11:02 PM | Permalink

    RE # 99

    It’s mind boggling to me that a widely accepted time in history that was warmer………………And every day we are told “Its never been hotter!

    Comment by welikerocks

    So back in the year 1000 when they said, “it’s never been hotter” they knew what they were talking about? Now with all our modern equipment and scientific analysis the uncertainty is too high to say, “it’s never been hotter”? EWWW-KAY!

  146. muirgeo
    Posted Aug 4, 2006 at 11:02 PM | Permalink

    RE # 99

    It’s mind boggling to me that a widely accepted time in history that was warmer………………And every day we are told “Its never been hotter!

    Comment by welikerocks

    So back in the year 1000 when they said, “it’s never been hotter” they knew what they were talking about? Now with all our modern equipment and scientific analysis the uncertainty is too high to say, “it’s never been hotter”? EWWW-KAY!

  147. Posted Aug 5, 2006 at 12:47 AM | Permalink

    Thanks Mark R. Good read, and good distraction from the hub-bub and circular going-nowhere arguing about the MWP and / or AGW.

  148. fFreddy
    Posted Aug 5, 2006 at 1:59 AM | Permalink

    Re #143, Allan M.R. MacRae

    As I said earlier, fossil fuels account for ~87% of global primary energy, and to significantly change this fact will be an undertaking of unprecedented global scope. By the time this happens, you and I will be long dead,

    Assume someone solves the problem of efficient energy storage – a “magic battery” which can pass energy in or out as quickly as you like, with a similar energy density to a tank of petrol. And which can be scaled up to industrial size.
    How would this affect your forecast ?

  149. fFreddy
    Posted Aug 5, 2006 at 2:02 AM | Permalink

    Re #120, KevinUK (and indeed Allan MacRae)

    Commercial scale generation of electricity from fusion is a myth – it will IMO never happen not in my lfetime or any of my five kids lifetimes.

    Why not ? What fundamental problems prevent this from being engineered to a workable solution ?
    (NB : this question is from total ignorance of practicalities of the subject)

  150. TCO
    Posted Aug 5, 2006 at 7:20 AM | Permalink

    I’ve been hanging on the U of A dendro listserv. There is some chick there who gets all huffy and liberal and mad at the skeptics but can’t actually be bothered to really make arguments or discuss details of science. Pretty much like the typical ad hom of PeterH and the like (along with the lack of math). There is also a comment by Luckman that “luckily he will be in the field” when methodological issues are debated. It really fits in with my whole impression of that field as having too many “outdoor hikers” given the tough math problems that they have. Statisticians or physcisists or someone need to start getting involved and fixing that field. Without permission.

  151. Steve McIntyre
    Posted Aug 5, 2006 at 7:59 AM | Permalink

    Has anyone read the Melinda Allen article in Current Anthropoplogy cited above supposedly showing a cool MWP in the Pacific? Is this based on new data – or is she, an anthropologist,using some other data set?

  152. Allan M.R. MacRae
    Posted Aug 5, 2006 at 8:05 AM | Permalink

    RE #146 from fFreddy:

    I said: As I said earlier, fossil fuels account for ~87% of global primary energy, and to significantly change this fact will be an undertaking of unprecedented global scope. By the time this happens, you and I will be long dead,

    You said: Assume someone solves the problem of efficient energy storage – a “magic battery” which can pass energy in or out as quickly as you like, with a similar energy density to a tank of petrol. And which can be scaled up to industrial size. How would this affect your forecast ?

    Assuming I understand your question correctly:

    There are five significant forms of primary energy on Earth:
    Oil, coal, natural gas, nuclear and hydroelectric.

    [Regrettably wind, solar, geothermal and other “renewables” don’t amount to much and likely never will, except in a few places like Iceland – this is in itself a major topic that I won’t expand on here.]

    What you are asking about is a “magic” (perfect) battery to store electricity. This is, in many ways, similar to the “magic” hydrogen solution that many are talking about. As I see it, electricity and hydrogen are both “secondary energy”, and you still need primary energy (one of the big five above) to create secondary energy.

    So in essence, a magic battery does not change my forecast much. What the magic battery would do, which is very significant, is that it would make electric cars (etc.) much more practical (their biggest downside now is range and cost). I would expect then to see a shift to increased generation of electricity (probably from nuclear sources) and a lesser role for oil (as converted to gasoline), as more and more cars are powered with electricity. So a “magic” battery would probably accelerate the growth of nuclear power at the expense of oil. The huge size of the fossil fuel infrastructure must be taken into account though – it will simply take many decades to make significant changes – it takes time and resources to build these massive energy complexes, even assuming the necessary consensus exists to do so.

    Regards, Allan

  153. Posted Aug 5, 2006 at 9:21 AM | Permalink

    Steve M said:

    Has anyone read the Melinda Allen article in Current Anthropoplogy cited above supposedly showing a cool MWP in the Pacific? Is this based on new data – or is she, an anthropologist,using some other data set?

    I just read the linked blurb. I’m no scientist (understatement of the year) but I was wondering if the apperent lack of a measureable MWP and LIA would be the result of the Pacific Ocean creating a climatalogical buffer zone and making long term temp change much less prominent by measure than that on the continents. Does that make sense???

    When I’m servicing pools in the early fall on cold mornings (yeah, I’m a lowely pool guy, told ya, no scientist I), the pool water and surface air above it is warmer than the ambeint air. If I measure the air temp right above the air matress floating in the middle of the pool, the air temp on the floating island would measure higher than the temp inland, say at my work truck…. er, Subaru turbo-wagon (the truck broke down this summer, plus the Subi has working A/C, is more compfy and fun to drive)?

    Sonicfrog – pool guy, future teacher, and geology school drop-out.

  154. Posted Aug 5, 2006 at 9:23 AM | Permalink

    PS. Wow, just proof read. I’m a horrible speller too 🙂

  155. KevinUK
    Posted Aug 5, 2006 at 9:23 AM | Permalink

    #147 and #150

    Allan as always you posts make sense and are informative.I was hoping you may say something about what you think of Canada’s nuclear technology i.e. CANDU? As an ex-nuclear technologist I am and have always have been a big fan of CANDU for several reasons – one being that the technology does not rely on enriching uranium. Since this blog is a Canadian blog then perhaps Steve won’t mind a slight diversion from dendro-chronoloy.

    fFreddy, there is lots of information on fusion power (a complete mis-nomer) on the internet but you won’t find much on electricty generation from fusion. This is why I called it a myth (in the context that Allan mentioned it). Strong choice of words I now but IMO factually correct. Have a look at the info on Wikipedia and some of the other web sites that promote it *at the expense of fission power) and I think you’ll find that like AGW alarmists the claims are somewhat exaggerated. They have a tendency to leave out minor details like just exactly where will the tritium come (in the D-T reaction) from, where will the energy for the confinement come from etc etc and of course ‘renaming’ what their projects stand for. For example ITER no longer stands for “International Thermonuclear Experimental Reactor” because that’s not PC and somewhat gives the game away a bit i.e. ‘experimental’. Instead they now prefer to say that ‘Iter’ is Latin for ‘the way’. Cost estimates for ITER are US$ 12.1 billion (IMO actual costs will be at least triple that). Here is a quote from Wikipedia

    “ITER is designed to produce approximately 500 MW (500,000,000 watts) of fusion power sustained for up to 500 seconds (compared to JET’s peak of 16 MW for less than a second). It is a significant amount of power for a fusion research project; a future fusion power plant would generate about 3000-4000 MW of thermal power. Although ITER will produce net power in the form of heat, the generated heat will not be used to generate any electricity.”

    Why on earth are taxpayers prepared to pay US$ 12.1 billion for 500MW of power (note once again the mis-nomer – at this stage its thermal power only) for 500 seconds. Oh and by the way this 500MW of heat will of course not generate any electricity. Still I’m sure we’ll learn a lot more about nuclear magnetic confinement and we’ll all sleep better at night for it.

    Kevin UK

  156. TCO
    Posted Aug 5, 2006 at 9:35 AM | Permalink


  157. fFreddy
    Posted Aug 5, 2006 at 9:36 AM | Permalink

    Re #150, Allan M.R. MacRae
    Allan, thank you. I entirely agree about primary and secondary energy, but my point was that part of the reason for the primacy of hydrocarbons is that you can switch the generators on and off when you want (roughly…). Hydrocarbons are a reasonably good store of energy.
    Wind and solar, on the other hand, do not have any storage characteristics. They only generate when the wind blows/sun shines, and don’t when it doesn’t. As such, they are a waste of space (and my taxes). Hence the report from Eon of Germany to which you posted a link recently, which explained what a horrible amount of wind generation was needed to replace oil-powered generation. (20 to 1 ?)
    My point about the magic battery scaling up to industrial size was that this would then give a wind station a storage capability – it could charge the battery when wind was available, then release predictable energy to the grid as appropriate.
    It seems to me that this should make a significant difference to the economics and practicality of wind plants, such that they might actually become sensible. Am I missing anything ?
    (Apologies for these ignorant questions, but you seem to know what you are talking about.)

  158. Dave Dardinger
    Posted Aug 5, 2006 at 10:19 AM | Permalink


    I’ve worked on CANDU reactors (well actually on steam generators for CANDU reactors, though the reason our company had to work on them reminds me of the Big Dig fiasco. The engineers who decided on how to heat treat the reactors after they were welded together didn’t allow for the fact that the tubes inside them would heat up and expand faster than the plates holding them in place, so the tubes bound up on the plates and bent. This wasn’t discovered until the first generators were tested under pressure in the field and leaked. Most were sent back to the shop to be reworked, but at three places, two in Canada and one in Argentina the domes had already been sealed up and there would have been big problems future-safety-wise cutting through the concrete so they were retubed on-site.

    But that’s neither here nor there, I did learn about the CANDU system. The big thing, of course, is that they use heavy water as the moderator rather than light water. So instead of enriching uranium, they have to enrich water. But at least once you have heavy water you have it forever (I suppose a little bit absorbs a neutron and becomes tritium, but apparently not much or else there’d be no advantage to deuterium to start with.)

    But what I don’t see anyone mentioning is using the Thorium cycle instead uranium in a fission reactor. Thorium has the advantage that when it absorbs an alpha particle it changes to uranium instead of plutonium. And this uranium then can be mixed with non-fissionable U238 to make it difficult to be used for bomb making. Indeed I think the proposed system uses a mixture of Thorium and Uranium so a rogue state like Iran couldn’t just separate out a fissionable isotope chemically.

  159. KevinUK
    Posted Aug 5, 2006 at 10:27 AM | Permalink

    #154, apologies TCO,

    I had to do a bit of background reading on SL-1 before I could give you a reply. I’ve done that now. I was born in 1960, went into the nuclear industry in 1981 and so had ‘missed out’ (was largely unaware of the details) on the SL-1 accident. There are certainly parallels with Chernobyl (e.g. prompt supercriticality) so I can see now why you have mentioned it but i’m not sure where you want to go with the discussion though?


  160. Steve McIntyre
    Posted Aug 5, 2006 at 10:39 AM | Permalink

    As TCO observed, the hockey stick was discussed in a number of posts at the U of Arizona dendro listserv that Dano keeps talking about as a supposed fount of knowledge. There sure wasn’t much light shed on the matter.

    There was much arm-waving about the "vast amount" of evidence indicating "unprecedented" warming. Here’s the sort of thing:

    If you want to focus on the flaws in a single paper (or a couple of old papers by the same research team) and ignore the vast amount of other documented evidence indicating unprecedented warming, go ahead. It’s easy to be unconvinced if you ignore the facts…

    Other sources of data exist for reconstructing climate prior to 1000 CE. Despite what Wegman claims, there are multiple independent lines of evidence that point to unprecedented warming for some time.

    So one contributor asked the person to list some of the "vast" and "multiple" lines of evidence:

    …I’m happy to read any others that you think bear directly on the question of warming trends during the MWP. I don’t have time to read them all, but I could manage a dozen or so.

    Doesn’t seem like an unreasonable request. I suspect that the inquirer was hoping for something other than the Dirty Dozen (MBH98, MBH99, Jones et al 1998, Mann and Jones 2003, Briffa 2000, Briffa et al 2001, Crowley and Lowery 2000, Esper et al 2002, Cook et al 2004, Rutherford et al 2005, Osborn and Briffa 2006,Moberg et al 2005, Hegerl et al 2006). He got neither. The answer:

    I’m sure that by this point in your career you know how to do a literature search. If not, too bad, but I don’t have time to teach you. It’s time for this exchange between you and I to end. Feel free to get in the last word. I won’t respond again.

    In Cleaveland’s comment, he mentioned three papers: Hassol 2004 – this turns out to be the Arctic Climate Impact Assessment Report – which, as I recall, doesn’t provide any evidence at the level we’re looking for; then Rignot and Kanagaratnam, 2006 – this appears to be a satellite study of Greenland ice sheets, which doesn’t seem to shed much light on medieval-modern relations; and Field et al 2006 (Sci 311, 63-66) on the California Current. The latter seems to be the only evidence not considered in the above brief synopsis – it is not even mentioned in the NAS panel report. It’s amazing how the key results are always the ones that are just in press with no data. Think of Thompson et al, Ann Glac in press, which supposedly has the key glacier evidence; or Allen, Current Anthropology. You’d have thought that there would be some articles from 2003 or 2004, or even 2000 or 2001, that would contain reliable evidence on the medieval-modern levels. It’s also amazing how many such studies are published in Reader’s Digest – oops, Science.

  161. KevinUK
    Posted Aug 5, 2006 at 10:59 AM | Permalink


    Thanks for mentioning the thorium fuel cycle and if Steve would bear with us just a bit longer for hijacking this thread, you have mentioned a very relevant point to the AGW debate. Relevant in the context that if nuclear power is to be the solution to AGW then we need to do nuclear power generation right second time round. If we are to IMO have a resurgence of nuclear power generation (whether for AGW mitigation purposes or not) then we MUST deal (along with the economics) with two key political issues a) new waste management b) nuclear proliferation.

    The politicians continue to deliberate on the issue of nuclear waste mamangement. My personal take on this is that the science has been done and the technology is here to handle it, but the eco-theologians don’t want a solution to this issue as once the issue is solved there will then be no reason not to re-start the nuclear power program once more. They want the waste to be visible, for as long as it is visible they know that the NIMBY principle will apply. Buried well below the surface in a geologically sound repository they know it will for all intents and purposes become a non-issue with joe-public.

    The eco-theologians continue to exploit the link (which I’m not going to deny) between the nuclear power generation programme and the nuclear weapons programme. As you’ve mentioned, one way to deal with this is to demonstrate to joe-public that nuclear power can deal with and indeed assist in the nuclear proliferation issue. This is why I like the CANDU technology in particular as it lends itself very well to the mixed oxide fuel cycle i.e the ‘burning’ of the legacy weopons programme plutonium as well as plutonium ‘enriched’ spent fuel from other reactor systems (DUPIC). You’ve also mentioned the potential for inbuilt non-proliferation through use of the thorium fuel cycle. And finally you’ve mentioned where the likely source of the Tritium for all those wonderful ‘non-polluting’ fusion power generation plants will come from. Are you reading this fFreddy?


  162. fFreddy
    Posted Aug 5, 2006 at 11:11 AM | Permalink

    Kevin, yes I am. According to the Wiki articles, a fusion plant can generate its own tritium outside the containment, by bashing lithium as part of absorbing the neutron flux. Is this an example of wikiality ? Or is lithium hard to come by ?

  163. KevinUK
    Posted Aug 5, 2006 at 11:32 AM | Permalink


    Then I think I’ve fed you enough. Hope you enjoyed the meal. Steve, the troll feeding session is now over.


    This is factually correct but is less economic than using the tritium which is a by-product of the CANDU recactor system. To generate tritium from Li-6 you need a neutron source. Guess where you get the neutron source from – not from a fusion reactor as they imply as you need one of them in the first place i.e. it’s a Catch 22 situation? Do you know appreciate just how exaggerated the claims for fusion power are? This is the same as with Fast Reactors, you need the plutonium to start them up and the a postive breeding ratio (genarate more plutonium from U238 than you burn) to ensure a lack of dependence on the much-maligned but essential thermal reactors.


  164. MarkR
    Posted Aug 5, 2006 at 11:43 AM | Permalink

    “As with the “Little Ice Age”, the posited “Medieval Warm Period” appears to have been less distinct, more moderate in amplitude, and somewhat different in timing at the hemispheric scale than is typically inferred for the conventionally-defined European epoch. …. The restricted evidence from the Southern Hemisphere, e.g., the Tasmanian tree-ring temperature reconstruction of Cook et al. (1999), shows no evidence for a distinct Medieval Warm Period.

    Medieval warmth appears, in large part, to have been restricted to areas in and neighbouring the North Atlantic. This may implicate the role of ocean circulation-related climate variability. The Bermuda rise sediment record of Keigwin (1996) suggests warm medieval conditions and cold 17th to 19th century conditions in the Sargasso Sea of the tropical North Atlantic. A sediment record just south of Newfoundland (Keigwin and Pickart, 1999), in contrast, indicates cold medieval and warm 16th to 19th century upper ocean temperatures. Keigwin and Pickart (1999) suggest that these temperature contrasts were associated with changes in ocean currents in the North Atlantic. They argue that the “Little Ice Age” and “Medieval Warm Period” in the Atlantic region may in large measure reflect century-scale changes in the North Atlantic Oscillation (see Section 2.6). Such regional changes in oceanic and atmospheric processes, which are also relevant to the natural variability of the climate on millennial and longer time-scales (see Section 2.4.2), are greatly diminished or absent in their influence on hemispheric or global mean temperatures.”

    “Tree-ring and radiocarbon dated advances from five major iceberg-calving glaciers along the Gulf of Alaska show ice expansions during the interval considered to be the Medieval Warm Period (MWP). Advances occurred along a 500km transect on the southern coast of Alaska during the 9th through 12th centuries.”


    “Claims that global average temperatures during Medieval times were warmer than present-day are based on a number of false premises that a) confuse past evidence of drought/precipitation with temperature evidence, b) fail to disinguish regional from global-scale temperature variations, and c) use the entire “20th century” to describe “modern” conditions , fail to differentiate between relatively cool early 20th century conditions and the anomalously warm late 20th century conditions.”

    “”Now, high-resolution paleoclimate records stretching back 1200 years confirm that the so-called Medieval Warm Period did not exist…” Link

  165. KevinUK
    Posted Aug 5, 2006 at 11:47 AM | Permalink


    Sorry fFreddy, forgot to also include Li-7 which is actual the more abundant isotope of the two. Plenty of info on lithium on Wikipedia if you want to read further.


  166. KevinUK
    Posted Aug 5, 2006 at 1:44 PM | Permalink


    OK just another morsel.

    the blogosphere

    seems that some people, don’t lke blogs and would not doubt prefer if we got our environmental info from ‘gatekeepered’ sources like Nature and Science.


  167. Bryn Hughes
    Posted Aug 5, 2006 at 3:13 PM | Permalink

    re 162 Mark R
    The proxy dates you rely on are inaccurate.I can demonstrate that the dates for the GISP2 core are inaccurate over the last 150 years. I doubt that the dates for 1000 years ago are in the least bit accurate.
    So your Alaska ice extensions could have happened before the MWP.
    ref.Loehle, C. 2004. Climate change: detection and attribution of trends from long-term geologic data.

  168. Steve McIntyre
    Posted Aug 5, 2006 at 4:06 PM | Permalink

    Bryn, I’m suspicious of some of the ice core datings as well. I compared Mayewki’s data from Everest to Thompson’s from Dasuopu which is nearby and got the sense that Thompson’s data were somewhat dilated, although far from being able to prove it. Can you provide more details on why you think that the dates are wrong?

  169. fFreddy
    Posted Aug 5, 2006 at 5:42 PM | Permalink

    Re #163, KevinUK

    Do you know appreciate just how exaggerated the claims for fusion power are?

    Hadn’t a clue. That’s why I’m asking questions.

  170. Steve Bloom
    Posted Aug 5, 2006 at 6:55 PM | Permalink

    That’s interesting, Bryn. Just out of curiosity, what do the citations to the Loehle paper have to say?

  171. MarkR
    Posted Aug 5, 2006 at 9:00 PM | Permalink

    Re#167 Brynn

    I don’t actually believe there wasn’t a MWP, LIA, or Dark Ages cold period. I just posted those extracts cos SteveM has been asking for the other side of it.

  172. Allan M.R. MacRae
    Posted Aug 5, 2006 at 11:35 PM | Permalink

    RE#157 from fFreddy:

    You are correct in your hyposthesis that a “magic” battery would greatly improve the nature of wind power. I frankly never imagined that your magic battery would be that big – I was thinking more of something that might run a car, from example. The latest Economist (July 29-Aug4/06) has an article on page 73 about an electric car called the Tesla. The two-seater reportedly costs US$89,000, accelerates 0-100kmph in 4 seconds, and can travel 400km on a single charge.

    The lithium-ion batteries are the big cost, I expect, and this cost must be reduced. Perhaps di-lithium crystals are the answer.

    One has to be careful when reading the Economist, however – they have been a consistent source of misinformation on the subject of global warming, having demostrated much bias and negligible competence.

    On the inside back cover of the same issue, Chevron says that a single hydrogen-powered car cost almost $1 million and hydrogen costs 4 times the price of gasoline to produce. Lots of room for improvment here.

    Best, Allan

  173. Bryn Hughes
    Posted Aug 6, 2006 at 12:13 AM | Permalink

    Re 168
    Steve M
    You could do a fourier analysis of the temperature curves and (as far as I can tell) you should get four main curves for each.Each proxy will yield curves with diferrent periods.But the periods of one proxy should be proportional to the those of the other. Since the periods MUST relate to variations in the sun (wnat else?) the dilation can’t be real.
    Re 170
    Steve B
    You tell me you obviously know.

  174. Allan M.R. MacRae
    Posted Aug 6, 2006 at 9:07 AM | Permalink

    Supplemental to #172 to fFreddy:

    RE big batteries – some friends in the 1970’s helped build a UK power-peaking scheme – water was pumped uphill to a reservoir during non-peak periods and then run downhill through a turbine to create electricity during peak demand periods – you can see that this was quite expensive, but it served as a big battery – probably it was quite inefficient – every time you convert energy you lose (often signficantly) some of the energy.

    For windmills, you might convert the energy to hydrogen for storage, although hydrogen is a poor fuel in my opinion – H2 contains very little energy and is hard to store. Methane is a vastly superior fuel except for the whole CO2-emissions hysteria. Funny that none of the hydrogen supporters have mentioned that when hydrogen is burned, it produces water vapour – another dreaded greenhouse gas!

    My Gawd, we’re all gonna die! We’re gonna burn, I tell ya! BURRRRN! Send lots of money to the Sierra Club, David Suzuki, and Al Gore. This is the only chance to save your loved ones from burning all to hell!!!

    Sorry, I got carried away a bit – this climate alarmist thing is kinda fun, y’know, and unlike the climate skeptics, I could make a lot of money. I’m thinking of changing sides…

    Regards, Allan 🙂

  175. KevinUK
    Posted Aug 6, 2006 at 10:56 AM | Permalink

    #174 Allan,

    I suspect that someone might mention Dinorwig in the context of ‘Big batteries’.

    fFreddy there is info on Dinorwig here.

    You may also be intereste dto know that most of the energy that is captured and stored and then subsequently release by Dinorwig come from the Wylfa nuclear Power station on nearby island of Anglesey (my wife and I spent our honeymoon on this island and visited Wylfa NPS while we were there – bit of a busman’s holiday). The water is pumped up from the lower lake to the higher lake using ‘off-peak’ electricity from Wylfa. When peak demand requires it the water is released to flow back through hydro-turbines from the upper to the lower lake. The turbines can effective ‘fire-up’ to peak load in approx. 16 secs. not a bad ‘big battery’ eh!

    Wylfa NPS (which has two Magnox reactors) is scheduled for closure in 2010 by which time it looks like the off-shore wind turbine farm just of Burbo bank in Liverpool Bay will come on-line. here is a link with some further info. Now I wonder just how much of the claimed 90MW of power which manage to get to Dinorwig and be able to pump some water from the lower to the upper lake? I will perhaps be one of the claimed 72,000 householders who will receive power from this wind farm. Looks like I’d better not flush the loo too often when the wind isn’t blowing after 2010.

    Allan, don’t join the other side no matter how much they offer you. You are needed here.


  176. beng
    Posted Aug 6, 2006 at 11:25 AM | Permalink

    I like the general approach of this topic. But I say the onus is on the HTeam (& the IPCC) to demonstrate that there are “cool” MWP proxies, or any evidence of MWP coolness. Wasn’t it they who declared that the previous “consensus” (~1990) was wrong? That the formerly recognized global warm & cool periods was a biased view, that therefore, by at least my simple logic, “cool” areas must have balanced out (pretty much exactly) the warm areas in time & variance.

    The HTeam & IPCC asserted this, but provided no evidence, as we’ve found out. If fact, as S_M demonstrates, just a cursory lit review (wasn’t NAS supposed to do that?) shows little credible evidence so far of coolness, but a bunch of warm MWP proxies.

    You’d think from all the talented & respected “research” people, at least one would step up to the plate & defend themselves. One must begin to assume they can’t…

  177. KevinUK
    Posted Aug 6, 2006 at 11:46 AM | Permalink

    #174 Allan

    Re: your commnt about the poor efficiency of hydrogen v methane as a fuel. I think you are missing the point. The eco-theologians worship at the altar of the harmless GHG water which as you know is the by-product of the re-combination (after it is first dissociated from O2 in water or C in methane by various means – all of which require energy) of hydrogen with O2. The ECO-T’s would have us believe that in the future we will all have solar PV cell panels powering electrolyzers that will produce hydrogen and oxygen through electrolysis and that we can then use this ‘stored energy’ to generate electricity or as a fuel in our cars. In other words a fully sustainable energy economy.

    Once again they will not admit that this will most likely never happen without at least an interim period in which the hydrogen energy economy will most likely first be established through the use of that nasty nuclear power. They also won’t admit to the fact the the majority of hydrogen production in the US today is via steam reforming of natural gas because of course natural gas is a fossil fuel and so is not a sustainable energy resource.


  178. Allan M.R. MacRae
    Posted Aug 6, 2006 at 11:52 AM | Permalink

    Re #175 from KevinUK:

    I have enjoyed your posts, and am very impressed with your knowledge of electrical power systems.

    As for me changing sides – this is not going to happen (unless the other side actually comes up with some truly convincing science, instead of their usual fellatious prophesies).

    In any case, I’m holding out for global cooling starting ~2015 …

    … and besides, I’m having too much fun tilting with windmills.

    Best, Allan 🙂

  179. beng
    Posted Aug 6, 2006 at 12:02 PM | Permalink

    RE 175:

    KevinUK, there are similar “pumped storage” plants in the US mid-atlantic. A large one (~600 MW potential) is Smyth Mountain Dam/Lake in SW VA. Typically it is “filled” at night by underutilized generators, & that stored water-head used during the high-demand periods the next day (the generator-motor & turbine-pumps are reversable).

    Keep in mind that this plant is actually a slight net user of electricity, not a producer (the water flow into the lake is negligible). However, it makes money but “straightening out” the daily output curves of the true generators & thus increases their thermal efficiency. And, as you point out, it can be used as a reliable & very fast “starter” after a major grid problem.

    Unfortunately or not, such projects (which make engineering sense) that create large lakes are pretty much politically impossible to do in this area at the present.

  180. Allan M.R. MacRae
    Posted Aug 6, 2006 at 12:16 PM | Permalink

    Re #177 from KevinUK, which I read after posting my #178.

    No arguments here Kevin – I agree with all this and have not missed the point – I thought it was obvious but probably it is not, so I appreciate your clarification.

    Our oilsands upgraders here in Alberta contain the largest H2 plants in the world, and operate by converting methane to H2 for heavy oil upgrading. This steam reforming process loses significant energy, and results in a much poorer quality fuel (methane vs. H2), so it would be extremely foolish to produce fuel H2 in this way.

    I don’t see much future for the production of fuel H2 from nuclear power either – I think the future H2 economy is a myth – the inefficiencies of all the energy conversions, the difficulty of storage and low energy of H2 are too problematic.

    I see more hope in better (small) batteries, but am not holding my breath.

    Going out now to chop down some trees, foul some streams and eat some baby robins…

    Best, Allan 🙂

  181. KevinUK
    Posted Aug 6, 2006 at 12:40 PM | Permalink

    allan, fFreddy and beng

    At some point Steve is going to tell us off for being way off the dendro-thread but I hope Steve is also enjoying our discourse as I note from some of his posts that he is interested in the ‘bigger picture’ of AGW and the possible role of nuclear power in its mitigation.

    As I’ve eluded to several times now the eco-t’s ‘want to have their cake and to eat it at the same time’. They preach the sustainable energy gospel but are not prepared to acknowledge how we (the non eco-t’s) in the real world will transition from where we are now to their eco-nirvana. They fail to understand that while we are doing this (the transition to eco-nirvana) our economy has to also remain sustainable otherwise there are no-taxes to pay for the R&D, no taxes to pay for the grants to continue the development and evolution of these sustainable technologies etc etc. I would personally take the eco-t’s a bit more seriously if they would at least acknowledge that the transition inevitably therefore has to be gradual. Instead they choose to play the political game and impose their belief on non-believers through political pressure (Kyoto protocol/accord). They distort scientific facts (e.g. AGW alarmism) and IMO they deliberately LIE (you know who’s names go here) and conceal the truth to their own political ends. They are anti-democratic. Their view (belief) is the only one that counts and the rest of us will just have to conform – NOT.

    Steve, I promise this is my final rant on this thread. Now come on lets get back to all this fascinating dendro stuff :-).


  182. KevinUK
    Posted Aug 6, 2006 at 1:06 PM | Permalink


    I hope you didn’t take any offence from the tone of my post in #177. None was intended.

    Thanks for the info on the oilsands in Alberta. I’ll read up on them after you post.

    If I’m honest, I’ll own up and reveal that I with you on the H2 energy economy. It is never going to happen is it because I think we know it is realiseable? But we can’t say that to the eco-t’s can we? Instead we got to play play along and if he net result is a lack of reliance on fossil fuel imports then at least something have been achieved.

    Don’t foget to count those tree-rings while your chopping down those trees and don’t over indulge in those robins as I believe the latest epidemiological study funded by the US EPA has shown that there is a clear link between passive robin eating and lung cancer (RR = 1.01) – Numberwatch.co.uk joke.

    Regards, KevinUK

  183. fFreddy
    Posted Aug 6, 2006 at 3:01 PM | Permalink

    Allan, Kevin, thank you. You’re quite right about Dinorwig – the thing that first got me interested in energy storage was when it refinanced itself with a bond issue, which implies that it has a very stable and predictable cashflow just from storing energy. It’s interesting that it is going to be linked into a wind factory – I would really like to see the economics of the whole system, to see if it can make sense without subsidy.
    Regarding hydrogen – totally daft. As you say, it is a storage technology. But unless some clever person can figure out a way to store the stuff that doesn’t require cryogenics or ruddy great high pressure vessels, it is going to be no use for cars, and dubious for industrial scale.
    Back to fusion – are you saying that you would use so much energy fissing (?) the lithium to tritium, that the net energy produced is no good ?

  184. KevinUK
    Posted Aug 6, 2006 at 5:53 PM | Permalink


    No. To explain this I’ll need to give you a quick explanation of the difference between fission and fusion. I apologise to any nucelar fusion experts reading for what follows as it is somewhat simplified explanation.

    As a self-confessed geology drop out (if you’d have perserved with the calculus I think you might have got up and over that learning curve) I think you’ll know about nuclei at the centre of atoms. Well fission is when a nucleus absorbs a neutron and so becomes unstable (not always, just some nuclei like U235 etc). This doesn’t really require much energy as such (in contrast to fusion – see later) only enough to create an initial stream of neutrons which when the unstable nuclei break up and create more neutrons so that there is a net balance between the number of neutrons absorbed and subsequently created in the fission process. This is called a sustained critical reaction. If you don’t create more neutrons than are absorbed then the chain reaction stops, if you create too many neutrons (and don’t absorb them) then the chain reaction runs away with itself and becomes what is termed supercritical reaction (as happened at SL-1 and Chernobyl). In the case of tritium breeding in a fusion rector this is a fission reaction (the Li-6/Li-7 absorb a neutron and create tritium and helium) but a unsustainable fission reaction in the case of the Li-7 is not possible.

    Now fusion is fundamentally different. It requires an injection of a very large amount of energy as it involves the forcing together of two nuclei, so that once they combine, they can release a net amount of energy largely in the form of the kinetic energy of the resultant fusion products, in the case of the D-T reaction this is a helium nucleus and a very energetic neutron. Some of these neutrons can be used for breeding tritium which once recycled can then be fed back into the D-T reaction. The kinetic energy from these fusion products will need somehow to be converted into electricity and it is this part of the fusion technology debate that has yet to progess much further than beyond the current paper study stage. The plan as I last saw it was (over a decade ago now) to use the Li-6 ‘blanket’ as both a breeder and as a coolant ciculating around the outside of the confined plasma and to use this in a conventional heat exchanger process to generate steam to turn a turbo-generator. Actually I’ve just been on the Jet/EFDA web site and found some info on the FAQs page here. It gives some details of the ‘lithium blanket’.

    This is a simplification but hopefully you now appreciate why fusion electricity generation is a long long way from commercial exploitation (they claim on the Jet/EFDA web site that it could be here by 2040-2050 – in their dreams).

    Happy fusion researching fFreddy, KevinUK

  185. Allan M.R. MacRae
    Posted Aug 6, 2006 at 11:59 PM | Permalink

    RE #182 – no offence take at all KevinUK.

    Again, I very much appreciate your posts – I learn from them.

    Actually spent the early part of the day enjoying a carriage driving competition at Spruce Meadows, then cold drinks and dinner on a patio, and a classical concert by top students at U of Calgary. Beautiful warm summer evening – I blame global warming.

    Chopping trees, fouling streasm and eating baby robins not really my thing – just trying to live-down to my image, as depicted by the AGW types.

    Best, Allan

  186. fFreddy
    Posted Aug 7, 2006 at 1:29 AM | Permalink

    Re #184, KevinUK
    Kevin, thank you. One slight misunderstanding: the geology school drop-out was someone else, I am a maths graduate.
    I’ve been trying to understand why you are so pessimistic about fusion power. In particular, are there any fundamental limits on its realistic ability to be useful.
    My comment about the lithium was based on my understanding that fission of a small atomic nucleus (up to and including iron) is an endothermic process: it absorbs energy. I was trying to understand if you were saying that most of the energy you get from the D-T fusion is used up by the Lithium fission to regenerate the tritium.
    Of course, if you are just saying that fusion power has huge technical difficulties that won’t be solved for decades, while fission power is a real, known technology that has been keeping the lights burning for decades, despite the interference of the greens – I can entirely relate to that.

  187. KevinUK
    Posted Aug 7, 2006 at 3:32 AM | Permalink


    fFreddy, sorry for confusing you with someone else (Lee?). Its the latter, but some of the former i.e. that the claims for fusion in terms of its costs and timscales for commercial expoitation have always been exaggerated. I’ve visited JET on a number of occasions because I used to work for the UKAEA and Culham was one of UKAEA’s sites. As an ‘attached staff’ member when I was seconded to and so worked at Torness NPS fro a couple of years in the late 80’s, I used to regularly visit the different UKAEA sites and listen to presentations from researchers and tour the facilities at these sites. What struck me on my first and subsequent visits to JET was just how large the facility is when seen in the context that it is only an experimental facility (ITER will b emuch larger). The computing power they had (presumably to analyse the plasma) also put NASA to shame. As with CERN it is testimony to how well funded one can be when you ‘hype’ the science/technology and get the politicians on your side. In contrast (at the time) alternative (to nucelar) energy research was showing significantly more potential funded on a relative shoestring (without the hype).


  188. Dan Hughes
    Posted Aug 7, 2006 at 6:05 AM | Permalink

    I don’t know how long Steve M will allow this discussion to go on, but fusion is not radioactively clean. The emitted neutrons will ‘contaminate’ the solid materials of which the power plant is constructed. I think this situation is due to the D-T reaction. At one time fusion proponents would proclaim it would be clean power, but the T had to be added to the D in order to increase the likely hood of breaking even on power production over power consumption. I recall that after the first D-T test at Princeton, the machine had to be shut down because of the radioactivity in the materials. The argument now is that the radioactive materials will have significantly shorter half-life than those from certain fission power generation methods.

    So, if fusion ever does emerge from the labs, and I don’t think it will, opponents will simply raise the same objections about ‘what will we do with all that waste’.

    KevinUK, did you ever interact with a small group of people in a Western US state who had produced a computer program whose acronym started with the letter ‘R’?

  189. KevinUK
    Posted Aug 7, 2006 at 6:30 AM | Permalink


    I’ll need a bit bigger clue than that to guess what the name of the computer program is. but I think the answer is most likely No as I’ve worked primarily on Advanced Gas-cooled Reactor (AGR) technology (ironically C02 is the coolant). I have done some work on PWRs and FR’s and nuclear decommissioning and waste management as well though (hence my mentions of why the latter two are important to the AGW debate). Given your question I guess you have a link with ‘R’?

    You’re spot on about the D-T problem (neutron activation of the confinement structure) and the fact that it is the only real promising (in terms of demonstrable positive Q value) fusion technology. One of my friends has been involved in the decommissioning plans for JET for many years now. The likelihood is that it will be left for the neutron induced radioactivity to decay away for quite sometime as is the case for most prototype reactor systems in the UK. The only facility to have been significantly decommissioned in the UK is WAGR, the Windscale AGR – a prototype for the CAGR. Whenever you see MSM TV images/pictures of the Sellafield (formerly Windscale) nuclear site you will almost always see two images, the WAGR ‘golfball’ and the Windscale piles ‘chimneys’. I’ve worked inside both of these facilities so know a lot about the legacies of the early nuclear programme.


  190. KevinUK
    Posted Aug 7, 2006 at 7:53 AM | Permalink


    OK my first guess is RETRAN-02/3D. I’ve come across transient analysis predictions using this program but have never used it myself. My second guess would be RANKERN which is a Monte-Carlo shielding code but as far as I know this was developed in the UK.


  191. beng
    Posted Aug 7, 2006 at 9:10 AM | Permalink

    RE 186:

    ffreddy, I’d have to generally agree w/KevinUK about fusion — it’s gonna be very difficult to put on a commercial scale even when & if it’s accomplished in the lab. It hard to contain a controlled fusion bomb. Centuries….

    Here’s my engineer’s solution: Fission is a demonstrated power-generating source. Using breeder reactors could quickly increase the potential fuel w/o much more uranium mining required. Extraction of uranuim from seawater is a long-term possibility. Fission could last centuries & power a mostly “nuclear/electric” society instead of fossil fuels. Battery cars, electric mass & freight transit, etc. Aircraft will still use hydrocarbon fuels, but that could still be synthed from organic materials if natural sources were depleted.

    It’s time to grow up and advance. 🙂

  192. Lee
    Posted Aug 13, 2006 at 11:10 AM | Permalink

    Well, I had left this site, until it was pointed out to me that Steve had once again posted an article referring to me without even the courtesy of sending me an email saying he had done so.

    As an aside, I’ve left because I got the answer I was looking for (dont rely on the dendro reconstructions, at least not yet), and because I’ve decided that Steve is very bright and very good and I don’t trust his honesty.

    I’m posting this one response because Steve spends several posts in this thread asking about comparisons of current tree lines with MWP-era tree lines – while completely failing to mention what I among others have pointed out several times, including directly to Steve more than once – which is that forests dont spring into immediate existence as soon as conditions become compatible with mature forests, and upward migration of tree lines is going to have significant time lags, and that this temporal lag has a major impact, and must be considered, for the argument he is alluding to about what present tree lines are telling us. Steve is WAY too intelligent not to realize this issue, and the fact that he (once again) posts without mentioning this issue, and in fact mentions direct such comparisons without mentioning this issue, is (to use the argument he made in the NAS criticism thread he alludes to in naming me in this article) “inexcusably negligent” and another example of why I don’t trust Steve.

    Now, I’m outa here – y’all have fun with this.

  193. Steve McIntyre
    Posted Aug 13, 2006 at 8:01 PM | Permalink

    Lee , I don’t understand what your beef is about what I’ve said on treeline equilibrium. Is there anything that you object to in the following? See here. It’s impossible for me to repeat everything in every post.

    Also neither the treeline nor the glacier are in equilibrium with the present climate and there is both more glacier retreat and more treeline advance in inventory even with no further temperature increase. It would be interesting to see what the present estimates are for what the treelines and glacier lines would be under present conditions.

  194. Lee
    Posted Aug 13, 2006 at 8:57 PM | Permalink


    There are glaciers there now, there were trees in the past: what’s your point? Or were you posting this "just because?"

    You make a point in the discussion that it must have been ‘warmer over a period of time.’ Which is simply wrong – it means that it reached or approached an equilibrium with higher treelines and glacier fronts that our current non-equilibrium state, and the climate that caused that equilibrium could easily have been consistnelty and continually cooler than our present non-equilibrium climate. One simply does not know from the comparison you shw in that post, and which formed the centerpiece image of your post.

    The fact is that you CAN NOT compare observed present non-equilibrium treelines and glacier fronts, and compare them to past potential-equilibrium or closer-to-equilibrium locations, and use that to compare past with present temps. "Warmer" is simply not a true word in this context.

    Your point in the sentence you cite here, about wanting to compare past observed and present calculated equilibrium positions, is defensible – but that isnt what the thread I link to was doing, and you didnt make that clarificatin to the dramatic visual you posted.

  195. welikerocks
    Posted Aug 13, 2006 at 9:07 PM | Permalink

    Lee, read the article:
    The glaciers, according to the new hypothesis, have shrunk down to almost nothing at least ten times since the last ice age 10,000 years ago. “At the time of the Roman Empire, for example, the glacier tongue was about 300 meters higher than today,” says Joerin. Indeed, Hannibal probably never saw a single big chunk of ice when he was crossing the Alps with his army.

  196. Lee
    Posted Aug 13, 2006 at 9:12 PM | Permalink

    rocks, I read that. I know that. It is a factimplicit in my respons to Steve. That is why I am discussng past equilibrium and present non-equilibrium conditions, usig Steve’s language here. If the equilibrium conditon at some time in the past was that there wer no glaciers at all, that STILL could not tell us what the temps were relative to today, simply by comparing with todays NON-equilibrium condition. Same point for tree lines.

  197. JMS
    Posted Aug 13, 2006 at 9:36 PM | Permalink

    Rocks in your head, Hannibal would not have seen any ice were he to cross the Alps today by the route that most historians suggest he used. The is no current glaciation on the Col du Mont Genevre. Check out Google Earth. It is amazing how fast this RWP meme has caught on here, when Hormes cites a glacial retreat phase circa 600 BCE but the next came in the MWP. Hannibal was c. 218 BCE.

    Of course as I pointed out in an earlier post, it snowed while Hannibal was crossing, of course the month was October…

  198. Steve McIntyre
    Posted Aug 13, 2006 at 9:45 PM | Permalink

    Lee, the cited authors on treelines – Naurzbaev et al 2004 and Millar et al 2006 – said that medieval temperatures were higher than present. That is evidence the other way – but as I said in the post, I wanted to ensure that I was canvassing all the evidence the other way, so that I was missing anything.

    Your arguments about treelines are irrelevant to this issue. As it stands, modern treelines are lower than medeival treelines and that is not evidence AGAINST a warmer MWP. You may have a plausible excuse – but it is just an excuse. I’m trying to summarize the evidence for a warmer modern warm period relative to the MWP and this line of discussion doesn’t enter into it as far as I see.

  199. welikerocks
    Posted Aug 13, 2006 at 9:58 PM | Permalink

    Lee I just quoted the article, Hannibul is not in my head. 🙂
    It said “10 times with no ice in that area since the last ice age” that’s the sentence that I thought was important.

    *The only argument against the evidence in this article is that these findings go against the consensus (models and proxies) that it it’s warmer now then ever before, is what I read.)

    Some Glacier terms to share I just looked up for myself 🙂 :

    Equilibrium line:
    Equilibrium line is the boundary between the accumulation area and the ablation area.

    Ablation refers to all processes by which snow, ice, or water in any form are lost from a glacier – the loss of snow or ice by evaporation and melting.

    Ablation area:
    Ablation area is the lower region of a glacier where snow ablation exceeds snowfall.

    Also if you google glacier animations, there’s even some time laspe video of Alphine glaciers doing there thing, and some good graphics to help you understand how glaciers work too.

  200. welikerocks
    Posted Aug 13, 2006 at 9:59 PM | Permalink

    I think it’s time to rest my eyes! Sorry for the typos! Sheesh!

  201. jcspe
    Posted Aug 13, 2006 at 10:08 PM | Permalink

    196. now I am really puzzled. On one hand, the warmers are all telling me I should believe in global warming largely because glaciers (Kilimanjaro and a few others seem to be favorites) are receding. Lee makes a case that higher temperatures are not necessarily required for glaciers to recede and for treelines to be higher. (And I would then guess, farther north.) Or, perhaps he is making the point that one should not be drawn into assuming that the actual position of a glacier or a tree line at any given date tells us very much about the temperature at that given date. If I understand his position, all that is required for a particular tree line location is the right starting condition and the passage of time.

    Did I understand Lee correctly? His point seems plausible. Suppose an ice age were to destroy all the trees north of Nebraska. Once the ice age receded (and during the recession), it seems entirely reasonable to believe it could take centuries before trees could reach northern Canada, even if temperatures in Canada were suitable to support those trees for a very long time before trees actually advanced that far.

    My problem is that I can not see why glacier position and tree line position can be both important to temperature reconstructions and unimportant to temperature reconstructions at the same time. Last time I checked the melting point was still 0 C.

    What am I missing?

  202. John Baltutis
    Posted Aug 14, 2006 at 1:46 AM | Permalink

    As I understand Lee, he contends that whatever happened in the past (more than 400 years ago) occurred under equilibrium condiitions, whereas everything that’s happened since is occurring under non-equilibrium conditions because mankind has started to tame his environment by using petroleum products and nuclear power to provide the electricity that powers labor-saving devices and climate controllers that heat and cool the buildings where most people in industrial countries live and work. And, that ain’t good.

  203. fFreddy
    Posted Aug 14, 2006 at 4:29 AM | Permalink

    For what little it’s worth, I keep getting confused between people talking about tree-lines as in how far North/South, versus tree-lines as in how far up a mountain. I think SteveM is talking about the latter.
    In either case, I can imagine that they will be reduced during a cooling phase much more quickly than they will recover during a warming phase. But I would have thought that warming recovery up a mountain would be much quicker than warming recovery going North.

  204. James Lane
    Posted Aug 14, 2006 at 5:11 AM | Permalink

    For what little it’s worth, I keep getting confused between people talking about tree-lines as in how far North/South, versus tree-lines as in how far up a mountain. I think SteveM is talking about the latter.

    That was my impression as well.

  205. Lee
    Posted Aug 14, 2006 at 9:20 AM | Permalink

    Steve, I never said it was evidence against a warmer MWP. I said it was no evidence either way. It could be cooler than now, but warm enough to cause glacial retreat, for long enough to retreat to those levels, It coudl be warmer. Given that we are still in retreat now, we dotn know from present lines where they weill retreat to, so simple comparison doesnt tell us about temps EITHER WAY.

    And remember that we are (as is so often reminded here) coming out of the little ice age, with glacial extention sufficient to override the morraines of previous glacial extentions and therefore greater than any extension since the end of the last glaciation, and therefore with further to retreat until glacial fronts/tree lines reach the new “stable” location around which they will oscilate in the new climate regime.

    re 202 – John Baltutis. No, that is not what I said. I was talking SPECIFICALLY about glacial fronts and tree lines, and the fact taht they (glacial fronts for sure, tree lines almost certailny, have not moved to the new ‘equilibrium’ location (using the language Steve used in the post he cited) for the tree line or glacial front. Where you got that I was saying what you say I was saying, I have no clue.

    Rocks, in using ‘equilibrium,’ I was following Steve’s language for stability of movement of tree lines and glacial front, and I was quite specific that I was talking about tree lines and glacial fronts. I know how glaciers work, I know what the equilibrium line is, and I knwo the proicesses by which glaciers extend or retreat. It would be good if you read what I actually say, for understanding, instead of assuming ignorance becasue I used a word in one context that you know in another context.

  206. welikerocks
    Posted Aug 14, 2006 at 9:43 AM | Permalink

    “It would be good if you read what I actually say, for understanding, instead of assuming ignorance becasue I used a word in one context that you know in another context.”

    You should stop assuming. I posted that for everyone, including my self, because I like geologic terms.
    And your post is very confusing, so 202’s comment isn’t so far fetched for “assuming” that’s what you meant because it also crossed my mind.

    So what IS the compelling evidence against the MWP then? I seem to recall that was a big issue you had. So far in all the topics made for this to be looked into I see none, including your argument about Steve’s wording here.

    IOW what are the “other evidences” that this is the warmest the Earth’s ever been in a long time?

  207. Steve Sadlov
    Posted Aug 14, 2006 at 10:28 AM | Permalink

    Warmism is a combination of uniformitarianism and Gaia worship.

  208. John A
    Posted Aug 14, 2006 at 10:30 AM | Permalink

    Steve S: please stop trying to write in platitudes. Evidence is good, empty rhetoric not good.

  209. Dave Dardinger
    Posted Aug 14, 2006 at 10:59 AM | Permalink

    re: #205

    (glacial fronts for sure, tree lines almost certailny, have not moved to the new “equilibrium’ location

    And just how do you know that glacier [shouldn’t it be glacier a noun rather than glacial an adjective?] fronts haven’t reached equilibrium? It seems to me you’re assuming that temperatures will stay the same or continue to go up? Some on the skeptic side have been claiming that temperatures have peaked while others say they will by about 2020. In that case a big vulcanic eruption or a random cooling fluxuation for a year or two might well stop retreats and then other natural cycles might start glacier fronts moving forward again. If you want to use glacier front retreat as evidence of warming [disequilibrium], then I don’t think it’s correct to use a past glacier front position as evidence of equilibrium. A glacier may be far from equilibrium, in a technical sense, when a change in temperature suddenly makes the old equilibrium position moot. So, the MWP position of a glacier might have been far lower than the position it might have reached if the climate hadn’t suddenly (or gradually) changed to a cooler one.

    Likewise on tree lines. If temperatures had stayed as high as the maximum reached in the MWP, then there might have been a much higher tree line either in altitude or latitude than was actually reached. That is, unless it’s possible to find fossil saplings and determine their ages.

  210. Lee
    Posted Aug 14, 2006 at 11:40 AM | Permalink

    re 209:

    Dave, that is essentially my point. The relevant comparison is between ‘equilibrium’ positions of the fronts, and whether the front reflects the equilibrium position is a damnably hard thing to know for past positions – that adds anothe rdimension of difficutly to teh analysis,a nd my point is taht one cant infer relative tempertures imply by looking at ice frotns now and ice frotns at some time in the past.

    We know that the current glacial front positions are not at the equilibrium position, because temeprstures curently are warming, and the ice fronts (and probably tree lines, although that is more an inference than an observation) are moving up. Sure, conditions could change tomorrow and reverse that, but that truism doesnt alter the argument about the analytic difficulties imposed by the current observable disequilibrium.

    There is an arguyment of a somewhat different kind that can be made the other way – if current fronts retreat beyond past limits, then we know that the integrated ‘conditions for glacial mainatainance over time’ (to coin a badly phrased term) are more extreme in the recent past than since the last time retreat exceeded the current retreat. If one has info about precipitation and history to add to that observation – which we apparently do have at least in part for a lot of glaciers – one may be able to infer relative temp comparisons. But again, simply observing relative fronts without looking at these other issues doesnt tell us much at all.

  211. beng
    Posted Aug 14, 2006 at 11:41 AM | Permalink

    RE 203: fFreddy sez:

    But I would have thought that warming recovery up a mountain would be much quicker than warming recovery going North.

    I’d think just the opposite — much greater reaction in distance moved for, say, flat-terrain tundra-limited trees than up/down mountains, at least generally. But the line of demarcation would naturally be harder to discern (isolated individuals & groves of trees invading the tundra).

    That would, in theory, make flat-terrain tundra/treelines perhaps a more sensitive indicator of climate change than mountainlines, at least in the local region of the “line”.

    Or, I’m just plain crazy.

  212. Dave Dardinger
    Posted Aug 14, 2006 at 1:43 PM | Permalink

    re: #210

    Dave, that is essentially my point.

    It doesn’t really sound like it is. BTW, perhaps it’s because I get distracted by your mountain of typos. If you’d just reread what you’d written before you post, you might be able to avoid several things; fuzzy thinking, typos, unfortunate ad homs, missing caveats, etc. I say that not out any sense of superiority, but because I know that I’ve elimated scads of all of those by rereading my own material before posting.

    However assuming we agree that we can’t deduce with much assurance the prevailing temperature just by observing evidence of a changed glacier front, then would you agree that a lot of warmers (or at least warmer wantabees), are making a mistake in attributing global warming significane to glacier front positions unless they are willing to provide evidence of due diligence in considering other factors? E.g. rainfall levels on Mt. Kilamanjaro?

    But getting back to equilibrium levels and how such a level would be calculated, how would you suggest we determine how close a glacier is to being in equilibrium? After all, if we can’t render a reasonable guess, why even discuss glaciers at all when it comes to temperatures?

  213. Dave B
    Posted Aug 14, 2006 at 2:00 PM | Permalink

    Am I missing something? it seems to me the very concept of “equilibrium” of glaciation is kind of a red herring. Isn’t it just an inflection point between net accumulation and net ablation? (or vice versa?).

    by glacial front (or glacier front), are you referring to “terminal moraine?”

  214. Lee
    Posted Aug 14, 2006 at 2:10 PM | Permalink

    I havent a clue who one would determine the equilibrium level of a glacier front, other than by observing it to be in equilibrium for some period of time.

    I know that there are detailed models of glacial dynamics, determined from a small subset of glaciers, and perhaps those would be of use, but I dont know the details of those. It would be useful ting to be able to do, and it would be very interesting to se those kinds of calculatin applied to some existing glaciers where we have historical data – but still difficult to interpret in terms of comparative conditions unless we had some way to determine that those glacial fronts were relatively static for some period of time when they were maximally retreated in the past, and therefore presumably near equilibrium.

    Note that this argument applies only to RELATIVE temps now and at times of maximal glacial retreat. Glacial observations are still of interest for a number of other uses. As one for-example, observed near-unanimous retreat in most or all regions worlwide, with observational attribution to temp rather than precip for most of it, which seems to be what we are observing (antarctica is a different and not well understood, but still overall warming, case), is good evidence of globally increasing temperatures in areas not subject to direct UHI effects. Note that this is still contested by a number of people.

    There are also some other inferences that can be logically made, given that we do ahve some history constraints. If the quelcayya rooted organic stands up, that tells us that the ‘integrated over time’ conditions leading to that uncovering worked quite rapidly – an observation potentially useful when comparing to glacial histories. The reason I consider the quelcayya find useful, if it holds up, is precisely because we know the recent history of the LIA, and that places some constraints on the ‘integration over time.’

  215. Lee
    Posted Aug 14, 2006 at 2:13 PM | Permalink

    215: Dave,

    I am using the language Steve introduced, and referring to the ice front – the front of the glacier, and whether its position is stable (in ‘equilibrium’) with regard to the climatic conditions that determine its position, or not yet stable because of recent changes in the climate. It is perhaps unfortunate language, given that the ‘equilibrium line’ has the specific and different meaning that you refer to.

  216. JCSPE
    Posted Aug 14, 2006 at 2:25 PM | Permalink

    215. I don’t think you are missing something. My instinct is that there is no such thing as equilibrium for glaciers unless it is measured in such short time frames that it would to be irrelevant.

    At any given time, a glacier is only a representation of the summation of past precipitation in relationship to pressure/temperature/radiation relationships that diminished runoff and sublimation. Variables such as the incline of the ground under the glacier, the insulating characteristics of upper layers and the heat generation effects of large pressures lower in the glacier also play roles.

    I would agree with Lee, one can not directly measure past temperatures from the current position or mass of a glacier. My frustration is that it seems both sides want to claim something else is true when it suits them.

  217. Dave B
    Posted Aug 14, 2006 at 2:42 PM | Permalink

    If the “Equilibrium Line” is the line above which accumulating snow JUST EQUALS ablating snow below it, well, it just seems kind of a foolish and non-useful construct. if it is snowing, the equilibrium line may well extend to the terminal moraine. An hour later, when the sun comes out, the equilibrium line might be at the summit of the mountain. Realistically, these would be extreme examples, but extreme weather does occur on mountains.

    Perhaps one can’t use glaciers as thermometers (and your point is well taken JCSPE), but clearly one CAN say conditions for net glacier ABLATION were better at the relevant time frames in the past.

  218. Lee
    Posted Aug 14, 2006 at 2:46 PM | Permalink

    Dave, I believe the equilbrium line concept refers to net accumulation and loss over the course of a year.

  219. KevinUK
    Posted Aug 14, 2006 at 3:17 PM | Permalink

    #191 beng,

    Have you ever heard of a gentleman called Walter Marshall? Walter Marshall is a former Chairman o fthe UK Atomic Energy Authority (UKAEA) and was also a Chairman of the UK Central Electricity Generating Board (CEGB) back in the days when in the UK we planned to build 10 new PWRs. In the end we only built one (Sizewell B) and opted for the ‘dash for gas’ instead. Walter Marshall was a key advocate of the PWR and once coined the phrase ‘Slow Breeder Reactor’. This was a mickey take on the mis-named ‘Fast Breeder Reactor’ (FBR) as the FBR most definitely did not breed plutonium fast. Indeed this was Walter’s way of eluding to the fact the the Dounreay FBR did not have a positive breeder co-efficient. Even as the UK DOE’s chief scientist and subsequently Chairman of the UKAEA he could see little point in the fast reactor fuel cycle. Sadly Lord Marshall of Goring died in 1996 and so did not live to see recent developments on energy policy within the UK. I wonder what he would have thought of the recent developments, namely Tony B’s backing for a new programme of nuclear power plants which will inevitably be based on the Sizwell B design. If he had lived longer he could well have eventually seen his plan finally come to fruitition.


  220. Dave B
    Posted Aug 14, 2006 at 3:58 PM | Permalink


    Whether annual, or daily, or decadal, it doesnt change the USEFULNESS (or lack thereof) of the concept.

    One can say that conditions for net ablation, or net accumulation, occurred during a certain time frame. Perhaps the inflection points of “equilibrium” could serve only to define the lengths of time over which these periods occur. Defining a long term warming or cooling trend, as you point out, is another thing altogether.

  221. welikerocks
    Posted Aug 14, 2006 at 9:44 PM | Permalink

    trivia regarding “Pinus cembra” or Swiss Stone Pine , the trees they found under the glacier.

    There seems to be conflicting ideas about this tree, some pages say it grows 3-4 feet per year, but on other fact pages it says “growth is slow”. An adult tree doesn’t have to be mature or tall , just produce cones.

    “Some grow rapidly, others slowly. Some have silvery foliage, others are dark green. They range in maturity from dwarfs to 100-foot-tall trees.”

    thought that was interesting.


  222. JerryB
    Posted Aug 15, 2006 at 8:21 AM | Permalink

    Re # 192,

    Lee wrote: “… – y’all have fun with this.”

    Shall we?

    Lee started that comment, as he often does, with a whine:

    “Well, I had left this site, until it was pointed out to me that Steve had once again posted an article referring to me without even the courtesy of sending me an email saying he had done so.”

    So, a bit of Lee’s childish pique is showing, but what else is new? Is Lee’s sudden interest in courtesy something more than a bit of polemical convenience? Perhaps a look at an example of Lee’s courtesy to others from one of his first posts on this blog may suggest an answer.

    In the thread Hergerl et al in this week’s Nature, tFreddy asked in comment 8 “Does Nature have an explicit policy of an embargo on data under review ?”

    Lee, in coment 23, after another one of his whines, responded with a rant which included the following gem: “And before you ask; find the link your own damn self. It isn’t difficult. You should have done it **before** you asked a question with scurrilous imputations. — ”

    Perhaps courtesy matters to Lee when it might serve Lee’s purposes, but otherwise, place your bets.

    In this current thread Lee went on to try to slur Steve M’s honesty, as he has attempted so often before. Hey, if you can’t beat Steve on the science, why not try a slur? But, as with courtesy, it might seem as if Lee’s regard for honesty may be a function of polemical convenience. Perhaps a few examples might be of some slight interest.

    In comment 17 of the thread Reverse engineering Hergerl et al. Lee wrote:

    “What I said was that I found it distressing to read, as a stated reason for your making those guesses, implications of dishonesty.”

    Well, no. That is not what Lee said. Therefore, that statement which Lee wrote about what Lee had said, clearly is false, no mindreading required. Does that imply that Lee is dishonest? How on earth, to borrow a phrase from Lee, is that NOT an implication of dishonesty?

    In comment 78 of the thread Nation Post Op Ed Lee wrote: “Steve, your op/ed implied that the comittee cut off ALL evidence at the knees, and that is simply not true.”

    To put it courteously: hogwash. The Op Ed expressed confidence that the other studies do not meet the methodological standards now recommended by the NAS panel. It did not state, or imply, or even merely suggest, that the NAS panel “cut off ALL evidence at the knees”.

    In comment 92 of that same thread, also referring to Steve, Lee wrote: “In fact, he SAYS it applies to all the evidence, … “, another of Lee’s fabrications, and another example of Lee’s attitude toward honesty when polemical convenience calls.

    It would be nice if Lee could actually try a bit of courtesy, and apologize to Steve for Lee’s various fallacious comments, but I’m not holding my breath. 🙂

  223. Patrick Trombly
    Posted May 30, 2007 at 4:07 PM | Permalink

    I don’t know how they dismiss as “anecdotal” the evidence of warmer climate when the anecdotes
    cover almost every portion of the earth from which there is data – from higher tree lines in
    the Sierra Nevadas to British vineyards and Alpine tree lines and glacier-free trade routes and
    everything in between. It would seem they’d have some obligation to explain how these things
    happened if not for a warmer climate or explain how the remaining corners of the world were
    so much colder that on average it was not warmer. It’s pure intellectual laziness that
    they haven’t even tried to do this.

    The only example they write about is the British vineyards, and have you seen Mann’s weak attempt
    at a rebuttal? Get this, he says that because they have vineyards there now, that means the vineyards
    there in the 11th century don’t prove warmer climes. Rrrrright, after 1000 years of breeding for
    cold-hardiness and improvements to growing techniques from greenhouses to synthetic blankets to
    cover the roots in winter, they grew new cold-hardy varieties of grapes in England – and in other
    cold areas like Vermont, Maine, etc…. And that’s relevant…. how?

    They do NOT grow in Britain the same kind of grapes they grow in Provence, nor do they use 11th century growing methods.

    They CAN’T, because it’s too COLD.

    They DID grow in Britain the same kind of grapes they grow in Provence, using 11th century growing
    methods, in the 11th century.

    Because it was WARMER THEN THAN IT IS TODAY!

    The sheer stupidity of Mann’s attempted rebuttal on this one is quite revealing.

  224. Steve Sadlov
    Posted May 30, 2007 at 4:54 PM | Permalink

    RE: #225 – Look at clothing. During the MWP, it was practically back down to tunics / togas again, albeit with tights instead of bare legs. Then, after the 1400s all the sudden clothing gets more bulky, maxing out during the 1700s with all the wool coats and knee breaches, massive collared shirts, wool tricorn hats, etc. Then, skimpier and skimpier leading into the current era.

  225. Philip B
    Posted May 31, 2007 at 4:20 AM | Permalink

    Re #225. That was exactly my reaction.

    Much of the ‘anecdotal evidence for wine production is from the Doomsday Book compiled on the orders of the William the Conquerer.

    It happens where I grew up in England (Harlow) is one of many places that produced wine, and the DB records show it was a substantial economic activity.

    This the DB record for another Essex location.

    Hundred of Rochford. Suen holds Rayleigh in demesne as one
    manor and 5 hides. Then 2 ploughs on the demesne, now 3. Always 10 ploughs belonging to the men. Then 21
    villeins, now 6. Then 6 bordars, now 15. Always 2 slaves. There are 10 acres of meadow and wood for 40 pigs. Now
    1 park, and 6 arpents of vineyard, which produce 20 muids of wine if it does well.
    Then 4 horses, 13 cows, 25 pigs, 105 sheep; now 5 horses, 2 colts,
    20 cows, 11 pigs, 80 sheep, and 11 goats. Then it was worth ⡱0, now the same without counting the wine.
    In this manor Suen has built his castle. Of this manor
    4 Frenchmen hold 2 hides, with 4 ploughs and 4 bordars, worth 60s. of the
    above total.

    An arpent is 3400 SqM or a bit less than an acre. A muid appears to be a wagon load.

  226. finings
    Posted May 31, 2007 at 4:49 AM | Permalink

    18,000 years of borehole temperatures worldwide

    Sourced from
    where Derning, Huang et al are discussed.

  227. Alex
    Posted Aug 9, 2011 at 2:27 PM | Permalink

    Didn’t I read that rougfly 1/3 of the temp stations has cooling trends so the global warming is not so global in the current era. I mean if they are gonne be picky about the MWP not being global lets be fair.

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