“More and more concerned about our statement”

In a previous post, I reported that Coordinating Lead Author Overpeck wanted to “deal a mortal blow to the misuse of supposed warm period terms and myths in the literature”. The MWP was one such target; the Holocene Optimum was another. Overpeck said that there was “no need to go into details on any but the MWP, but good to mention the others in the same dismissive effort“, referring to the Holocene Thermal Maximum [Holocene Optimum] in the next sentence.

In today’a post, I’m going to discuss a July 31, 2006 (725. 1154353922.txt) email from IPCC Lead Author Olga Solomina who sent the following email to Overpeck expressing “more and more concern” about the IPCC statement that “the Early Holocene was cool in the tropics” – an assertion that was critical to Overpeck’s “mortal blow” project:

Hello everybody,
I attach here a version of glacier box and suggestions (in red) how to include there the reference to the new Thompson et al., 2006 paper.

In this relation – I am getting more and more concern about our statement that the Early Holocene was cool in the tropics – this paper shows that it was, actually, warm – ice core evidences+glaciers were smaller than now in the tropical Andes. The glaciers in the Southern Hemisphere (Porter, 2000, review paper) were also smaller than at least in the Neoglacial. We do not cite Porter’s paper for the reason that we actually do not know how to explain this – orbital reason does not work for the SH, but if we do cite it (which is fair) we have to say that during the Early to Mid Holocene glaciers were smaller than later in both Northen, and Southern Hemisphere, including the tropics, which would contradict to our statement in the Holocene chapter and the bullet. It is probably too late to rise these questions, but still just to draw your attention.

I am going to Kamchatka tomorrow, but will be avaliable by e-mail from time to time.

All the best,

Nice to read of a climate scientist who isn’t going to Tahiti. Obviously, her interpretation of why the Porter review paper was not discussed in this context is disquieting.

The Solomina comment relates to the discussion of the Holocene Optimum in section entitled: Was any part of the current interglacial period warmer than the late 20th century?

Overpeck and coauthors first acknowledged higher Holocene Optimum temperatures in mid-northern latitudes:

Climate reconstructions in the mid-northern latitudes exhibit a long-term decline in SST from the warmer early- to mid-Holocene to the cooler late-Holocene pre-industrial period (Johnsen et al., 2001; Marchal et al., 2002; Andersen et al., 2004; Kim et al., 2004), most likely in response to annual mean and summer orbital forcings at these latitudes. Near ice sheet remnants in northern Europe or western North America, peak warmth is locally delayed, probably as a result of the interplay between ice elevation, albedo, atmospheric and oceanic heat transport and orbital forcing (MacDonald et al., 2000; Kaufman et al., 2004). The warmest period in northern Europe and western north America occurs from 7 to 5 ka (Davis et al., 2003; Kaufman et al., 2004). During this mid-Holocene period, global pollen-based reconstructions (Prentice, 1998; Prentice et al., 2000) show a widespread northward expansion of northern temperate forest (Bigelow et al., 2003; Kaplan et al., 2003), as well as substantial glacier retreat (see Box 6.3).

Although the warmth in high northern latitudes is attributed to Milankowitch insolation variations, they also note early warm periods at high southern latitudes (New Zealand, South Africa, Antarctica), suggesting that “large-scale reorganisation of latitudinal heat transport may have been responsible”:

Other early warm periods are identified in the equatorial west Pacific (Stott et al 2004), China (He et al., 2004), New Zealand (Williams et al, 2004), south Africa (Holmgren et al, 2003) and Antarctica (Masson et al., 2000). At high southern latitudes, the early warm period cannot be explained by local summer insolation changes (see Box 6.1), suggesting that large-scale reorganisation of latitudinal heat transport may have been responsible.

Now the key point at issue: they asserted that the tropics behaved oppositely to the extratropics – warming since the Holocene Optimum:

In contrast, tropical temperature reconstructions, only available from marine records, show that tropical Atlantic, Pacific, Indian Ocean SSTs exhibit a progressive warming from the beginning of the current interglacial onwards (Rimbu et al., 2004; Stott et al., 2004), possibly a reflection of annual mean insolation change (Figure 6.5).

The above sentence is relied upon by Overpeck et al rely on in arguing against a global Holocene Optimum:

When considering the periods of largest temperature changes (Figure 6.9), paleoclimatic records of the Holocene provide no conclusive evidence for globally synchronous warm periods, especially because the temperature trends appear distinct in the low versus mid- and high-latitudes during the Holocene (Lorentz et al, 2006).

This idea was illustrated in IPCC Figure 6.9 – the blue rectangle denotes the “cool” tropics:

Overpeck replied to Solomina’s email as follows:

Hi Olga – it is not too late to ask these good questions. Glaciers can, of course, be affected by both temp and precip changes, so the question is really for Valerie (land) and Eystein (ocean) – are the land and ocean data from the tropics strong enough to outweigh what the glaciers are saying about tropical temps earlier in the Holocene? Lonnie’s Figure 8 (see attached) presents Hauscaran and Kilimanjaro data that suggest early to mid warmth in tropical South America and Africa that is (if the O-isotopes are temp) greater than today. Personally, I’m quite unsure that these are reliable temperature records, BUT if we want to make that case, we have to be convincing. What do terrestrial and ocean temp data say?

Thanks Olga for sending the proposed revised text – I think Eystein is putting finishing touches on the next draft for LA etc. review.

Masson-Delmotte chipped in as follows;

It seems to me that there is still a large uncertainty about the temperature versus precipitation effect on these tropical glaciers. Other indications from south America are related to lake levels with contrasted views in the low versus highlands.

Several references suggest that there is the end of a wet period after the early Holocene in tropical south America ; this is expected to induce an increase of 18O signals.

One review was conducted several years ago within the PEPI project (http://wwwpaztcn.wr.usgs.gov/pcaw/ and references herein).

I think that the state of the art is that we have no reliable proxy record that is sensivite to temperature only on the tropical lands for the Holocene; therefore the statement that was written for the Holocene was based on areas of the tropical oceans where SST reconstructions were published.

Do we have to write more explicitely about the uncertainty?


Jansen, who is an ocean sediment guy, concluded the discussion in the Climategate window, as follows:

Hi Olga,
I agree with Valerie that the ice core evidence is ambiguous. I would personally place more weight on the alkenone data, which is a reasonable well calibrated SST proxy. Foraminifer transfer function based SSTs and some Mg/Ca results that are available suggest a similar picture as far as I know. Of course it is possible and plausible that the tropical oceans are behaving in a non consistent manner and not all areas are showing the same signal, but a sizeable portion appear to do so in order to conclude as we do in the chapter in my opinion. Some signals may be due to changes in in trade wind induced coastal upwelling strength, but there are enough cores with alkenone data outside of these areas. If we were to say more about the uncertainties it may be the fact that proxies are seasonally skewed.
My conclusion is to let the chapter say what we say at the moment.

I’ve bolded an important Jansen statement noting that some signals may be due to changes in “trade wind induced coastal upwelling strength”, but “there are enough cores with alkenone data outside of these areas.”

One reason why Jansen took care to distinguish upwelling zones is that upwelling zones in the 20th century appear to go opposite to the general trend of increasing SST. For example, an upwelling zone off Morocco has had exceptionally cold alkenone SST results in high-resolution data covering the 20th century -see CA discussion of Cape Ghir data here.

Interestingly, I had already wondered in Janurary 2007 about the potential impact of coastal upwelling sites on IPCC’s analysis of the Holocene Optimum and had assessed the sites in Lorenz et al 2006 against exactly this standard. See here .

In that post, I observed (long before Jansen’s comment became available through Climategate) that 5 of the 7 Lorenz et al tropical cores with a Holocene Optimum “cooler” than the present were from upwelling zones: three from the Arabian Sea, one from Cariaco (Venezuela) and one from Benguela.

Despite Jansen’s assertion that “there are enough cores with alkenone data outside [upwelling] areas”, there were only two tropical cores in Lorenz 2006 Figure 3 that purported to show a “cooler” Holocene Optimum (as against three that showed a warmer Holocene Optimum). And there are question marks against both of these cores – question marks not flagged in IPCC’s zeal to “deal a mortal blow” to the “myth” of the Holocene Optimum. Here is Lorenz et al Figure 3:

One Lorenz core (Core #12: GeoB5844-2) was from the northern Red Sea, where a major reorganization involving the Mediterranean dramatically changed salinities during the Holocene. Arz et al (Mediterranean Moisture Source for an Early-Holocene Humid Period in the Northern Red Sea) stated:

Paleosalinity and terrigenous sediment input changes reconstructed on two sediment cores from the northernmost Red Sea were used to infer hydrological changes at the southern margin of the Mediterranean climate zone during the Holocene. Between approximately 9.25 and 7.25 thousand years ago, about 3per-thousand reduced surface water salinities and enhanced fluvial sediment input suggest substantially higher rainfall and freshwater runoff, which thereafter decreased to modern values. The northern Red Sea humid interval is best explained by enhancement and southward extension of rainfall from Mediterranean sources, possibly involving strengthened early-Holocene Arctic Oscillation patterns and a regional monsoon-type circulation induced by increased land-sea temperature contrasts. We conclude that Afro-Asian monsoonal rains did not cross the subtropical desert zone during the early to mid-Holocene.

Changes in salinity can affect oxygen isotope; I am not familiar enough with alkenone data to comment on whether such dramatic changes in salinity would have any impact on the alkenone data. However, it’s something that one would like to see specifically excluded and commented on before placing too much reliance on the record. Aside from that, the northern Red Sea is hardly a type case for the world’s tropical oceans.

The other non-upwelling tropical core in Figure 3 is from the North China Sea (17940-2), where, once again, there was a major reorganization during the Holocene. Offshore southeast Asia has by far the greatest area of land that has been submerged during the Holocene – much submerged area today was dry in the LGM. This rearrangement also rearranged salinities and again one would want to see a specific exclusion and, if necessary, allowance for salinity in this area. Stott’s Mg-Ca temperature reconstruction in the Holocene for the nearby Pacific Warm Pool shows a warm Holocene Optimum. Needless to say, IPCC didn’t bother trying to reconcile the inconsistency. [Update: Reader tty in a comment draws attention to Leduc et al 2010, which attempts to reconcile Mg/Ca and alkenone results in a comprehensive survey. Leduc, G., Schneider, R., Kim, J.-H., Lohmann, G.(2010). Holocene and Eemian sea surface temperature trends as revealed by alkenone and Mg/Ca paleothermometry, Quaternary Science Reviews, 29(7-8), 989-1004. http://epic.awi.de/Publications/Led2010a.pdf%5D

Lorenz et al Figure 4 shows a larger population of sites than the 20 sites illustrated in Figure 3. However, the identity of the sites is not easy to determine on the present record. Lorenz et al stated:

All SST records were from ocean margin sites with sedimentation rates sufficiently high to provide SST records with at least one value per 1000 years. Detailed information on each SST record are given by Kim and Schneider [2004], including the original data references.

Kim and Schneider 2004 is: Kim, J.-H., and R. R. Schneider (2004), GHOST global database for alkenone-derived Holocene
sea-surface temperature records, http://www.pangaea.de/Projects/GHOST/, PANGAEA Network for Geol. and Environ. Data,
Bremerhaven, Germany. Unfortunately, this site is password-protected. I requested a password a couple of years ago, but received no acknowledgement and didn’t pursue the matter.

Lorenz et al 2006 Figure 4

Even without a full identification of all the cores, it can readily be seen that the core locations do not even approximately provide a random sample of the tropical Pacific, Indian – they are on continental shelfs. The sites in Figure 3 are illustrative in the sense that the sites with “cooler” alkenone Holocene Optimum are in the upwelling Arabian Sea, upwelling offshore Venezuela, upwelling Benguela, plus the Red Sea and the “Maritime Continent” shelf of southeast Asia. No samples from the open ocean.

Overpeck and associates didn’t report that glaciers in the Early Holocene were smaller than at present, as Solomina had proposed, choosing not to cite Thompson et al 2006 at all.

Update Apr 9, 2010: Leduc et al (2010) attempts to carry out the reconciliation between alkenone and Mg/Ca proxies ( a desideratum that I mentioned in my post of January 2007). It is an excellent article. It concludes:

The compilation of SST data available for the Holocene and derived from two different proxies (alkenone unsaturation vs. Mg/Ca ratios) suggests that the processes that drive the sedimentary record of the interglacial SST evolution may be unexpectedly complex and our understanding is only fragmentary. Although the alkenone-derived SST trends previously identified are robust, they are not reproduced by the Mg/Ca-derived SST records.

On the low-latitude warming indicated in the alkenone data (and relied upon by IPCC), they observe:

Why the global and persistent warming trend is recorded in almost all of the low-latitude alkenone records as such a strong Holocene SST feature (Figs. 1 and 3 a–c) is more puzzling, and can only be explained if alkenone-derived SST records are assumed to reflect the boreal winter season since it coincides with an insolation increase in the tropics. Therefore another factor may have had an impact at low latitudes, e.g., nutrient availability instead of light, since light is not a limiting factor for primary productivity at low latitudes. Possible is that in the permanently stratified tropical ocean where light is no limited low-nutrient surface waters are influenced seasonally by upwelling that acts synchronously to increase the surface water nutrient content – favouring primary productivity – and to decrease SST, potentially making coccolithophorids susceptible to blooms when SSTs are below the mean annual average. A feature that is in agreement with recent satellite observations for an inverse relationship at low latitudes between net primary productivity and temperature, the link between these processes being the upper ocean stratification (Behrenfeld et al., 2006).


  1. timetochooseagain
    Posted Apr 8, 2010 at 7:36 PM | Permalink

    In Climate Of Extremes Michaels and Balling discuss figure 6.9 and an oddity with regard to how it was put together. It underwent several interesting revisions.

    Look at slide 40 here:

    Click to access Pat_Michaels_PowerPoint.pdf

    That’s what it looked like in the First Order Draft. The very next slide is the final version, shown above in this post. Although Michaels focused on the changes in how MacDonald (2000) on Siberia was cited (the graphic VASTLY understates what he found) notice how the tropical cool spot changes-first it’s “tropical atlantic and east pacific” and in the final it somehow becomes the North Indian and the entire tropical pacific. The period also gets longer. The lengthening of the tropical cool period versus the shortening of the Siberian warmth is a stark contrast. AFAIK the references the IPCC gave were the same for all versions of the figure.

    • timetochooseagain
      Posted Apr 8, 2010 at 8:30 PM | Permalink

      Correction-for some reason the figure shown above doesn’t seem to match Michaels’ “final” version quite right. Steve, is that the final version of the figure? I looks more like the Second Order Draft figure in Michaels’ book.

      • Posted Apr 9, 2010 at 3:46 AM | Permalink

        Re: timetochooseagain (Apr 8 20:30), You are right, Steve’s picture is not the final version of IPCC fig 6.9. The final version is similar but has a couple more red patches in the NH (‘Nordic seas’, ‘North Eurasia’). Steve has used the version from the 2nd order draft, March 2006, probably because this is the version they were discussing in these emails. The Michaels presentation uses the FOD and the final version.

        Steve: I’ll annotate the caption accordingly.

  2. ML
    Posted Apr 8, 2010 at 7:48 PM | Permalink

    There is a link to “woodoo science” as called by IPCC Guru

    Click to access MoEF%20Discussion%20Paper%20_him.pdf

    Long, but you can start from page 48
    Chapter 8
    Global Warming and
    the Glacier Retreat – A Review

    steve: off-topic. Nothing to do with the Early Holocene.

  3. artwest
    Posted Apr 8, 2010 at 8:36 PM | Permalink

    Hate to nit-pick, but I assume you’d prefer to know about apparent typos, Steve.

    “The above sentence is relied upon by Overpeck et al rely on in arguing against a global Holocene Optimum:…”

    “Nor did Overpeck and associates didn’t report that glaciers…”

    • justbeau
      Posted Apr 8, 2010 at 9:34 PM | Permalink

      The title is “more concerned”, while the email is “more concern.”

  4. justbeau
    Posted Apr 8, 2010 at 9:43 PM | Permalink

    Splendid essay by McIntyre. The East Anglia emails provide a wonderful contemporaneous record by shedding light on misinterpretations, as they happenned.

  5. Willis Eschenbach
    Posted Apr 8, 2010 at 10:18 PM | Permalink

    Y’know, every time I read one of these forays into the fetid depths of the CRU emails, I come away more amazed at the brazen quality of how they describe what they are doing. They are not looking for a scientific effort, they are looking for a “dismissive effort”. They don’t want to find out the truth about the MWP, they are interested in “dealing a mortal blow” to the MWP.

    I know I shouldn’t be surprised, but I was born yesterday, I’m still not used to this kind of “science” …

    Back to the point. The Bermuda Station S records (Keigwin 1996, subscription only, overview here) show very clear cooling over the period of the late Holocene. They show a cooling of more than 2°C in the Bermuda (32°N) SST.

    So if they want to claim the Early Holocene was “cool”, I’d have to ask, “Compared to what? To the present? To the later Holocene?”.

    Also, I truly don’t understand their claim in Fig. 6.9 above that the “Western Tropical Pacific” was only warmer (more than a half degree) than the present from about 11,000 to 9,000 years ago. Their reference for this is Stott 2004 … but Stott shows three drill cores, and only one of the three shows that pattern. The other two show the warm period extending much closer to the present. And all three show a pattern of a general decrease in SST from around 8-10,000 years ago. One of the three (MD81) shows SSTs a full degree warmer in the last thousand years … get out the mallet, we have to smash that high temperature down.

    Me, I suspect that because Keigwin clearly shows both the Little Ice Age and the MWP, it was unable to survive the “mortal blow” to the MWP …

    • Steve McIntyre
      Posted Apr 8, 2010 at 11:26 PM | Permalink

      Re: Willis Eschenbach (Apr 8 22:18),

      Willis, your observation that the IPCC characterization of Stott et al 2004 is entirely correct. IPCC reviewer Michel Cricufix made the same point in First Draft Comments as follows;

      6-1036 A 21:57 22:1 east Pacific warming. This statement is not backed by the quoted references. Rimbu et al. only consider the Atlantic, while Stott et al. (Nature) document a (this is the title) “decline of surface temperature […] in the western Pacific ocean in the Holocene”.

      IPCC merely replied:

      New Lorentz et al GRL paper

      • Willis Eschenbach
        Posted Apr 9, 2010 at 12:03 AM | Permalink

        That’s good to know, Steve, because my interpretation of the Stott paper’s data was so far afield from the IPCC interpretation that I was afraid that I was missing something obvious.

  6. Posted Apr 8, 2010 at 10:31 PM | Permalink


    I thought about sending this as an email, but then reconsidered with climategate in mind. I said it before, you are the single non-government person familiar enough with the various proxies and methods to put the whole mess into context. It cannot be done by someone as interested as myself, b/c there is too much foundation work to learn. Each email to my eyes, even those having so many suggestive over-conclusions, requires many hours of study. People don’t realize just how much work you have into this.

    The MWP is not dead, Nic sent me to a stack of papers tonight and despite my new dad exhaustion, I’m still reading. Every reader here should understand that AGW has got to kill the MWP, if they don’t then today is not that exceptional. It’s a very big pressure on the political class of the science. It’s enough of a pressure that some scientists aren’t clean.

    It doesn’t mean that the scientists in question aren’t right, it does mean that many efforts of dotting i’s and t’s aren’t being completed in a fashion which demonstrates their conclusions. We the hapless, are left with a big pile of Swiss cheese logic and a political consensus result.

  7. Steve McIntyre
    Posted Apr 8, 2010 at 11:21 PM | Permalink

    I’ve edited this post to include a discussion of Lorenz et al 2006 Figure 4. As noted in the post, I am presently unable to identify the non-Figure 3 sites, since the dataset is password protected. I anticipate adding back some commentary if and when I’m able to identify the sites.

  8. richard telford
    Posted Apr 9, 2010 at 2:27 AM | Permalink

    The data might be protected at http://www.pangaea.de/Projects/GHOST/ , but the reference list isn’t.

    Open-ocean sedimentation rates are typically rather low, insufficient for Holocene scale reconstructions. Upwelling areas have high biological productivity, so high sedimentation rates, sometimes even with anoxia reducing bioturbation. Great places for a high resolution record, but not necessarily representative of the open ocean.

    Steve: An article being relied upon by IPCC for a result should not have password protected data. End of story. Climate scientists should be the ones who need to be most offended by this – not me.

  9. Dave McK
    Posted Apr 9, 2010 at 6:30 AM | Permalink

    You do excellent work, Steve. Real work.
    There’s not a pundit I wouldn’t be happy to chase out of a dark alley with a mop, but I’m glad I’ll never be on the wrong side of a McIntyre. I’d rather climb into a dumpster full of lawyers.
    Nobody is

  10. tty
    Posted Apr 9, 2010 at 6:43 AM | Permalink

    Most of the data from figure 4 seems to be summarized and referenced in this paper:

    Leduc, G., Schneider, R., Kim, J.-H., Lohmann, G.(2010). Holocene and Eemian sea surface temperature
    trends as revealed by alkenone and Mg/Ca paleothermometry, Quaternary Science Reviews, 29(7-8), 989-

    available at:

    Click to access Led2010a.pdf

    Interestingly it indicates that Alkenone and Mg/Ca proxies give opposite temporal trends for tropical waters. The paper suggests that this is due to the proxies sampling different seasons. I don’t find this wholly convincing since alkenone also indicates rising tropical SST temperatures during the previous interglacial, while all other proxies (palynology, fauna, oxygen isotopes, speleothems etc) I’ve ever heard of agree that temperatures were highest early in the interglacial and then declined.

  11. Posted Apr 9, 2010 at 7:54 AM | Permalink

    It looks like a classic case of confirmation bias. Let’s be critical of information that conflicts with our preconceived beliefs, and accepting of what confirms them.

    Steve, I hope that you pay your staff well for for all the hard work and overtime they do to compile and analyze all of this data 🙂

    • Craig Loehle
      Posted Apr 9, 2010 at 9:25 AM | Permalink

      Confirmation bias is why peer review is required–everyone is susceptible to it. Imagine if authors could over-rule/ignore all reviewer comments, as IPCC chapter authors do!

    • Tom C
      Posted Apr 9, 2010 at 10:15 PM | Permalink

      Actually it’s not a classic case of confirmation bias. A classic case would be subtle and hard to discern. This is blatant and egregious. More like pathological, obsessive, gang-like confirmation bias.

  12. Posted Apr 9, 2010 at 11:36 AM | Permalink

    The Porter Review paper that Olgo Solomina refers to, that the IPCC did not cite, is
    Onset of Neoglaciation in the Southern Hemisphere,
    JOURNAL OF QUATERNARY SCIENCE (2000) 15 (4) 395–408.

    It is mainly about the onset of a cool period (“neoglaciation”) around 5000 years BP, as determined by advancing glaciers.

    The statement “We do not cite Porter’s paper for the reason that we actually do not know how to explain this” is alarming. If scientists adopted this attitude, scientific progress would be minimal. Clearly she felt awkward about it, but must have been persuaded by the evidence-free statements of her co-authors that the glacier increase was due to increased precipitation rather than falling temperature.

    Here is one interesting sentence from Porter’s paper, relevant to the alleged cool tropics:
    Thouret et al. (1996) inferred that the timberline in the Colombian Andes was 300–500 m higher than now between ca. 7400 and 3600 yr ago, implying air temperatures 1–2°C warmer than now and a higher snowline“.
    No prizes for guessing whether Thouret et al was cited by the IPCC.

    • tty
      Posted Apr 9, 2010 at 4:43 PM | Permalink

      Unless the lapse rate is somehow much lower in Colombia than elsewhere a 300-500 m higher treeline implies approximately 2.0-3.5 degrees centigrade warming.

    • Duster
      Posted Apr 9, 2010 at 6:26 PM | Permalink

      Those two observations taken together are quite interesting. They imply 1) advancing glaciers 5,000 years ago, 2) DURING a period 7,400 to 3,600 years when the Colombian Andes timber line climbed between about 1,000 and 1,6000 feet. Conjointly that suggests that either glaciers advanced during a “warm” period, or that timberlines were NOT responding to temperature as a limiting factor.

      • tty
        Posted Apr 10, 2010 at 4:31 AM | Permalink

        The neoglaciation was in the southern Andes and southern New Zealand, i e southern temperate zone. The Colombian Andes are in the northern Tropics, climate changes need not be synchronous. I would say that in the Northern Andes temperature is probably the limiting factor, except for a few dry valleys on the eastern side of the main range.

  13. UK John
    Posted Apr 9, 2010 at 2:19 PM | Permalink

    An example of “Vodoo science”.

  14. Posted Apr 9, 2010 at 3:10 PM | Permalink

    Try this Steve: 😉 http://ghost.pangaea.de/Data/

    Steve; thanks. strange…. http://ghost.pangaea.de/data.html has a password protection.

    • tty
      Posted Apr 9, 2010 at 4:54 PM | Permalink

      Oh dear, these are genuine computer wizards. They have password protection if you follow the “regular entry” in, but forgot to protect the actual data subdirectory!

      • Posted Apr 9, 2010 at 7:04 PM | Permalink

        Actually, they have dutifully archived the data in a Scientific Commons type website that directly links to the active directories. These folks should be applauded for archiving the data. Also, Google helped immensely.


    • oneuniverse
      Posted Apr 10, 2010 at 7:55 AM | Permalink

      Re: Ryan Maue (Apr 9 15:10),

      The Excel files on the Data page of the GHOST project’s home site ( http://ghost.pangaea.de/ ) are password-protected, for some reason.

      The data files are accessible if searched for via http://www.pangaea.de/ .

  15. Brooks Hurd
    Posted Apr 9, 2010 at 4:03 PM | Permalink


    Once again – great work!

    Willis put it very well above: “They don’t want to find out the truth.”

    I really do not understand how people can call themselves scientists and cherry pick some data and completely ignore other data to prove their pre-conceived notions.

    • justbeau
      Posted Apr 9, 2010 at 8:16 PM | Permalink

      Peck needs to save the Earth. He is a confounding director for the Institute for the Environment, a big man on campus. A Nobel laureate thanks to epic service to the IPCC. Peck has volunteered to save the Earth against the terrible threat that has been identified by Al and Captain Jim.
      It would take a lot of backbone for Peck to say, wait a minute, there is no clear evidence of warming. Peck does what one would reasonably expect. Don’t worry Olga, assures Peck, your thoughtful concerns and good science will be accommodated. How is Dr. Olga going to find out about Peck’s double cross, from the Kamchatka?

      • OldUnixHead
        Posted Apr 10, 2010 at 3:13 PM | Permalink

        on Apr 9, 2010 at 8:16 PM

        “confounding director”. Freudian? 🙂

        • justbeau
          Posted Apr 10, 2010 at 3:34 PM | Permalink

          While sometimes I typo, to err is human and all that, this particular typo was deliberate.

  16. 1DandyTroll
    Posted Apr 9, 2010 at 6:09 PM | Permalink

    So essentially you have now shoved two true gigantic torpedoes up Overpecks “behind”, which of course need proper time to be felt.

  17. Barclay E MacDonald
    Posted Apr 9, 2010 at 8:40 PM | Permalink

    In the LeDuc et al quote above it states, “Although the alkenone-derived SST trends previously identified are robust, they are not reproduced by the Mg/Ca-derived SST records.” I’m not sure what is meant by “robust”. As used here it appears inherently contradictory. Or maybe “robust” just means something like thorough or complete.

    • tty
      Posted Apr 10, 2010 at 4:35 AM | Permalink

      I should think that in this context it means that the data are reproducible and that the trends are consistent and statistically significant. It is the interpretation that is shaky.

  18. Steve McIntyre
    Posted Apr 9, 2010 at 9:35 PM | Permalink

    This is a little utility script to read the alkenone data.

    for(i in 1:46) {alk[[i]]=test[,4*(i-1)+(2:4)]}

    info= read.xls(“temp.xls”,sheet=1,from=6,colClasses=”character”)
    for (i in 1:46) { names(alk[[i]])=c(“depth”,”age”,”temp”); alk[[i]]=alk[[i]][!is.na(alk[[i]][,1]),]}
    for(i in 3:5) info[,i]=as.numeric(info[,i])

  19. Posted Apr 10, 2010 at 7:17 AM | Permalink

    I find their assumptions of the cause of the Holocene warm period, while plausible, far from hard proof. They have not eliminated all other possible sources/causes, they just wave their hands and proclaim.

    It is truly pathetic. What is really disgusting (and I mean that seriously) is how this group of so called scientists pawn off a hypothesis as proven fact, then claim no other hypothesis is valid.

    Science is not just dying in front of our eyes, it has died.

    • Dodgy Geezer
      Posted Apr 11, 2010 at 3:04 AM | Permalink

      Climate Audit studiously maintains a dispassionate technical attitude, and that is one of its strengths. The other is, of course, that it is right.

      Because of this emphasis on technical accuracy, issues of morality and politics are usually seen as important, but not a fit topic to discuss here. I will not discuss them, but would like to draw readers attention to a quote from Theodore Dalrymple, which makes the point that technical accuracy is not divorced from morality – indeed, it underlies it. Dalrymple is speaking about the corrosive effect of political correctness and the requirement under some communist societies to claim that ‘everything is fine’, but the words, and the implications, are equally applicable to AGW:

      “…When people are forced to remain silent when they are being told the most obvious lies, or even worse when they are forced to repeat the lies themselves, they lose once and for all their sense of probity. To assent to obvious lies is to co-operate with evil, and in some small way to become evil oneself. One’s standing to resist anything is thus eroded, and even destroyed. A society of emasculated liars is easy to control.”


  20. Andre Bijkerk
    Posted Apr 10, 2010 at 2:00 PM | Permalink

    The key issue about the sea surface temperature seems to be that it is a ‘proxy’ for the atmospheric temperatures. How certain is that?

    I heard that the scorching hot summer in Europe went together with a persistent cold SST spot in the mid atlantic where the low pressure areas are generated normally that bring cool moist summers to Europe.

    Wouldn’t low SST obstruct convection and evaporation, causing less cloud forming, latent heat tranport, and hence a lower albedo, with more insolation and hence higher lower atmosphere temperature? And vice versa of course.

    Or would basic meteorology not work in paleoclimatologic suppositions?

  21. EdeF
    Posted Apr 11, 2010 at 11:21 AM | Permalink

    There is a bit of Graphology at work in Fig 6.9 above……we have warming in the
    northern latitudes, heat in the south, sunbathing in the mid-latitudes, toasting
    all around. Even some warmth in equitorial Africa. But then there is this giant
    BLUE box that covers the whole tropics. See, its warm all around, but in the
    tropics its mighty cool, ergo, there aint no such thing as the Holocene Maximum.
    Nope, nothing to see here. This is Power Point Trick # 7 at work…..have seen it
    a million times, not fooled. Wonder how in the world they would think anyone would
    not see it.

  22. Peter Dunford
    Posted Apr 11, 2010 at 1:59 PM | Permalink

    Lorenz Et Al Figure 3 has some very interestng choices of vertical scale. Manipulation of perception.

  23. Posted May 6, 2010 at 1:44 AM | Permalink

    Each page of the pangaea domain show the contact email . just a short email to notify the operators about access problems might be straitforward instead of searching around and writing scripts. we will remove the protection and add the most recent version of the data which is open access at

    Steve: thank you for this. I had submitted a request for password access on a previous occasion and had not received any response. I had not pursued the matter. Unfortunately, I’d had little luck in some comparable situations where I had pursued matters.

  24. Guillaume Leduc
    Posted May 20, 2010 at 4:41 AM | Permalink

    I’d like to clarify some issues on that post.

    First, the GHOST dataset used to be password-protected since the hard work of building the dataset was devoted to bring together proxy people and model people working on model-data comparisons (note one dataset builder would like to publish first after the painful work undertook instead of making it available to everybody). Once the dataset used as a tool was spread in the literature it certainly should have been available to the community. Occasionally, one fair data digger should admit that a simple mail to the corresponding authors may have led to receiving the dataset directly from the author. This being said, the extended database is now available on PANGAEA thanks to Hannes Grobe, but note it’s a hard work as well to finalize archiving a tremendous amount of data and related information (two months and dozens of mails of correspondence between Hannes and me finally permitted to undertake the archiving of all these data).

    On the reliability of alkenones, I am not aware of any publication reporting convincing evidence for a supposed salinity bias on this temperature proxy. By the way, using the term “bias” to describe contrasted trends is misleading once the trends are confirmed by a large amount of regional cores but collected in different localities. Instead of pointing out bias, one should admit that Mg/Ca and alkenones that are well-established – although not perfect – proxies, just bring different stories. I would rather tend to see new rooms for resolving seasonality issues by applying multi-proxy analysis on marine cores.

    The seasonal hypothesis we propose in the Leduc paper is a first attempt to reconcile opposite SST trends, especially in the tropics as observed by different proxies. We do not claim that we solve every discrepancy since we come up with a simple conceptual model to explain such contrasted trends that appear to be a global feature at low latitudes. We indeed wrote in the abstract “Although this “ecology hypothesis” fails to explain all of the available results, we argue that any other mechanism would fail to satisfactorily explain the observed SST discrepancies among proxies”. There are enough terms in the paper such as “suggest”, “propose”, “hypothesize” that dismiss any criticism I read in the comments above (AJStrata: “They have not eliminated all other possible sources/causes […] What is really disgusting (and I mean that seriously) is how this group of so called scientists pawn off a hypothesis as proven fact, then claim no other hypothesis is valid.”)

    To tty: “The paper suggests that this is due to the proxies sampling different seasons. I don’t find this wholly convincing since alkenone also indicates rising tropical SST temperatures during the previous interglacial, while all other proxies (palynology, fauna, oxygen isotopes, speleothems etc) I’ve ever heard of agree that temperatures were highest early in the interglacial and then declined.” If long-term climate trends are due to changes in orbital parameters (as somehow admitted for the Holocene period), then one should look into the effect of precession of the climate records. By definition, any climate record bearing a precessional cyclicity has to be seasonally-weighted since there is no change in annual-mean insolation triggered by precession. As alkenones seem to follow boreal winter insolation changes within the tropics, it is not surprising to observe other climate records such as “palynology, fauna, oxygen isotopes, speleothems etc” that are rather summer-sensitive, i.e. will be impacted by an insolation trend that is antiphased as compared to winter. My personal point of view is that one should take care of the seasonality impact on climate geological records, since seasons are expected to be overwhelmingly shaping climate records (speleothems are perhaps the best example).

    To say the obvious, the Leduc paper was not purposed to come up with an explanation for why in the IPCC fig. 6.9 the tropics were unconclusive. Rather, the database will be used as a target in paleomodelling experiment projects. The IPCC builds up on the peer-review litterature, but the contrary is generally not.

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  1. […] and covered it up. This has become clear in the CRU emails and documents made public last fall, as emphasized by the esteemed Steve McIntyre. I am getting more and more concern about our statement that the Early Holocene was cool in the […]

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