Lonnie Thompson’s work is prominently cited by Al Gore, was cited by the NAS panel of Surface Temperature Reconstructions and is used both in temperature reconstructions and in articles arguing that there was no MWP. One of the remarkable aspects of Thomspon’s corpus is both that the original sample data is unarchived – even for cores that are now over 20 years old – and that Thompson has published many inconsistent versions of key data sets (e.g Dunde dO18 as illustrated below).

Dunde Versions. Heavy black — Yao et al 2006 (3 year rolling average); thin black – MBH98 (annual); red – PNAS 2006 (5-year averages); blue – Clim Chg 2003 (10-year averages); purple – Yang et al 2002 (values in 50 -year intervals); green – Crowley and Lowery 2000 (original in standardized format, re-fitted here for display by regression fit to MBH98).
I’ve been trying for several years to obtain Thompson’s sample data so that these inconsistent results can be reconciled without any success. Last year, Thompson published yet another inconsistent version of his ice core data in the Proceedings of the National Academy of Sciences. PNAS has policies that explicitly require authors to archive data sets – see here. I reported earlier this year on letters to NAS asking them to require Thompson to comply with their data policies. My initial inquiry got nowhere as noted here.
I had asked PNAS to require the following:
I request that you ensure that Thompson et al comply with your data policy by forthwith archiving the large datasets used in the PNAS article for each individual ice core (Dunde, Dasuopu, Guliya, Puruoganri, Quelccaya, Sajama, Huascaran) and for the entire suite of isotopes and chemistry. In addition, because the discrepancies may result from changing algorithms for dating the ice cores, I further request that the dating procedure for each core be made available under your Unique Materials policy.
On Apr 30, 2007, not receiving any reply, I sent them a reminder:
Dear Sirs, I didn’t receive any acknowledgement for the request below. Can you advise me on the situation? Regards, Steve McIntyre
On May 10, 2007, Michael Baden-Campbell of PNAS replied. According to his reply, Thompson had claimed (falsely) that the requested data had already been archived. The falseness of this claim could have been easily ascertained had the PNAS editor actually examined the links, but the PNAS editor did no such due diligence. Here is his answer:
Thank you for your messages and your interest in PNAS. I apologize for the delay in getting back to you, but I wanted to speak with Dr. Thompson about this request personally and he was out of the office for quite some time. I was able to reach him via phone the other day, however, and can now address your query. According to Dr. Thompson, the data you seek have all been deposited in the archive you specifically mentioned as well as being mirrored on his own website. Let me know if you have any further questions.
LAter that day, I sent PNAS a detailed letter observing that Thompson’s answer was false and that the data said to have been archived had not been archived. My letter is as follows:
Dear Mr Campbell,
Unfortunately, the following response from Dr Thompson is simply false:
According to Dr. Thompson, the data you seek have all been deposited in the archive you specifically mentioned as well as being mirrored on his own website
I am perfectly aware of the highly incomplete summary information archived at WDCP and at Dr Thompson’s website. Indeed, I used this information to plot the attached figure. You can readily verify for yourself that Dr Thompson’s answer is false.
My request was as follows:
“Thompson et al 2006 describe results from ice cores drilled at Dunde, Guliya, Dasuopu, Puruogangri, Quelccaya, Huascaran and Sajama. For each core, several thousand samples were taken and analyses on a sample-by-sample basis made for isotopes, chemistry and other indicators. The information for each core constitutes a large data set within the meaning of your policies.”
In a responsive data archive, you could identify the sample number, top, bottom, isotope, chemistry and other indicators. Since several thousand samples were taken for each core, there would be several thousand lines in the archive. If there was more than one core for a site, each core would require a separate data file.
In the case of (say) the Dunde ice core, the only information archived by Thompson at WDCP is here:
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/trop/dunde/dunde-d18o.txt
This only covers isotope information for part of the core and this is not an a sample-by-sample basis but has been aggregated into decadal averages. The same for other sites.
I re-iterate my request that PNAS ensure that Thompson comply with PNAS policies on these data sets.
Regards, Steve McIntyre
Not hearing back from him, on May 30, 2007, I asked again:
Amy progress with this?
On June 21, still without any reply, I sent another letter, copy to Ralph Cicerone, Persident of NAS, as follows:
Dear Sir, I have received no response to this. As I said in my earlier email, Dr Thompson’s answer on data availability to you was false. I gave you a specific method to verify that his answer was false. Please advise on me on the status of this request and whether you plan to ensure compliance with PNAS policies. Regards, Steve McIntyre
On July 26, I sent another reminder, this time copying Gerry North as well as Ralph Cicerone.
As noted below, Lonnie Thompson’s response in connection to the availability of data was false. I provided you with detailed evidence showing this. Would you please take steps to require Thompson to ocmply with PNAS policies on data availability or rescind the article in question. Regards, Steve McIntyre
On July 29, I received the following letter from Cicerone refusing to intervene:
After receiving your July 26 electronic mail, I inquired again about the Thompson et. al. paper and related data.
Dr. Thompson states, and the PNAS editors concur, that he has met the conditions of publication as stated by PNAS, for example, in PNAS Information for Authors under journal policies.
Have you ever tried to write to him directly at Ohio State University, or to inquire about whether any OSU reports might be available with even more of the meta data that you seek?
Yours sincerely, R. J. Cicerone
I replied as follows:
Dear Dr Cicerone,
I asked for the sample data in order to reconcile inconsistent versions of Guliya and other data sets. At this time, the data is unavailable to resolve these inconsistencies as outlined in my original request. I strongly disagree that the data provided by Thompson complies with PNAS policies and believe that your decision in this matter is incorrect. Do PNAS policies offer an avenue in which I can appeal your decision?
While I disagree that PNAS policies correctly interpreted permit the present obstruction and obfuscation, if this is your view, then you should immediately re-examine your policies to ensure that they are modified so that they no longer permit obstruction and obfuscation in the future. You might consider asking the panel on data archiving for advice in this respect, if you are unable to develop adequate policies yourself.
Upon re-reading my original request, I note that one aspect of the request pertained to meta-data and, while I have asked Thompson for data – which he has not provided – , I have not specifically asked him for meta-data. I will request such information from him, but, given his track record of obstruction, I do not expect any success. It would have been more appropriate had PNAS made the request as I asked.
Your performance in this matter has been shameful. The issues of climate change are important and neither you nor the National Academy of Sciences should be parties to the efforts of certain scientists to obstruct the archiving of important data.
Regards, Steve McIntyre