A late report on my visit to Holland. I don’t think that I’ve talked as much in a month as I did in 36 hours in Holland. I had two main presentations -one at KNMI in the morning; one at the Free University in the afternoon. I also had two long newspaper interviews and a long meeting on Friday morning with a Dutch mathematician. After the KNMI presentation, I had lunch with Rob van Dorland, Nanne Weber, Jos de Laat of KJNMI, all of whom were very cordial, and spent much of the afternoon talking with them.
Throughout I was very cordially entertained and guided by Marcel Crok of NWT (and his charming wife) Any success that I had was largely due to Marcel’s initiative.
At the Free University lecture, there were some CA readers: Ferdinand Engelbeen, Hans Erren, Hans Labohm; and perhaps a couple of others. (Larry and Lena Hulden were at the Stockholm conference and I had a chance to talk to them there.) Ferdinand kindly gave me some very interesting Belgian beers; Hans Erren a 2003 Burgundy – from the hot summer. All in all, I felt very welcome in Holland.
The Lion’s Den?
KNMI is the Dutch meteorological institute. It is located in De Bilt, which is a train ride outside Amsterdam. There were about 40-50 people present for my presentation.
KNMI has felt obliged to respond to criticisms of the Hockey Stick. They ran an endorsement of the Hockey Stick in their website in February 2005; in a newspaper article by Rob van Dorland in October 2005 and, most recently, in its most recent Annual Report in August 2006, where they said that the “points criticised by McIntyre and McKitrick have been mostly refuted in various studies”.
They are participating in a new study (MITRIE headed by Martin Juckes – see for example) of the Hockey Stick financed by the Dutch government, involving pretty much the European Hockey Team (Briffa, Moberg, Esper) plus Nanne Weber from KNMI. This study will be submitted to Climates of the Past in the next couple of weeks. (I wasn’t given a copy of the article to comment on.)
Last spring, KNMI had a workshop on the Hockey Stick at which Marcel Crok of NWT gave a presentation. He had also interviewed Nanne Weber in the spring, so I had a pretty good idea of their ideas and background. For example, Crok’s notes on his interview indicated that she believed the following:
ⵉWe had failed to show the impact of Mann’s PC methodology on the NH reconstruction even though this was shown in our EE article(which she had not read);
ⵉYou have to take more PC’s into account until you represent the underlying dataset well enough (without going into detail about Preisendorfer rule she said something like: you add new PC’s until the sum of the PC’s is not changing anymore).
ⵉIt’s not easy to see what’s the effect of the decenterd PCA on the end result, so you have to calculate it. Von Storch and Zorita did this with pseudo proxies, concluding it has little effect.
ⵉW&A showed according to her that there is no difference in end result between centered and decentered PCA
ⵉShe claimed that W&A showed that a simple average of all the MBH data gives a hockey stick as well;
ⵉWhen asked about WA confirming that the R2 failure, she told Crok that
she was not a specialist on this and that Martin Juckes was responsible for this. When asked by Crok whether she had investigated the R2 failure, she said that she hadn’t and had no intention to do.
ⵉWhen asked by Crok whether they were planning to calculate the error bars in MBH, she said that she would ask Juckes about this as well.
ⵉShe gave Crok a copy of the EOS paper of July 12 2005 in which I was slagged by Crowley. Crok told her that he had read a lot of the correspondence and that I was nowhere not friendly. She said that I was equally responsible that things got out of hand.
ⵉshe said that she understood why people don’t want to make their data available: they invested so much time in it and it’s so much work to archive everything.
ⵉCrok asked her about the crucial datasets: Polar Urals, Tornetrask, bristlecone pines and foxtails. She told Crok that Tornetrask is only in Esper and Moberg and Polar Urals only in Mann & Jones, Crowley and Lowery and Esper, but would look into it and come back to him on it.
So while most of the audience were unfamiliar with the territory, KNMI as an institution had taken an active interest in the matter and had been officially both critical and dismissive. My trip to KNMI was supposed to be a trip into the lion’s den.
I sometimes get the impression that some of my critics expect me to fold at the most minor confrontation. Any one expecting blood on the floor of the stadium would have been disappointed. The scientists were polite. The questions tended to be pretty general rather than about proxy reconstructions. None were hard or even detailed questions – somewhat surprising given the previous statements by the institution.
Now one can’t draw any very strong conclusions from this; I might simply have bored then to tears. My presentation at KNMI was definitely the weakest of the three presentations as I tried too hard to bring in details to argue against the Weber perceptions and completely missed my time markers. However, the people stayed for the over-length presentation and seemed politely interested. I think that I conveyed an impression that I knew my material and that I was fairly pleasant. I am increasingly coming to the view that that is all you can do with technical material in this type of presentation. For actual technical points, you are are really just trying to interest people in what you’re doing rather than presenting information that is going to convert anyone.
I was interested in trying to persuade Weber and von Dortland about the fatal weakness of Wahl and Ammann. I presented the diagram about von Storch and Zorita that had interested von Storch in Stockholm – noting von Storch’s comments in Stockholm that he now understood how a contaminant proxy could affect a network. My position on Wahl and Ammann is that their results yield a q.e.d.:
ⵉThey say that reconstructions without bristlecones/foxtails have no climatological meaning because of failed RE statistics. We agree with this;
ⵉThe NAS panel, following earlier articles and recommendations by Graybill and Idso 1993; IPCC 2AR; Biondi et al 1999; etc. stated that strip-bark should be avoided in temperature reconstructions;
ⵉStrip-bark avoidance includes the bristlecone/foxtail sites
ⵉtherefore MBH cannot assert 20th century uniqueness based on their data and methods as stated in McIntyre and McKitrick 2003. q.e.d.
This argument seems completely obvious to me. It seems obvious to anyone that is not a climate scientist. However, climate scientists seem to feel that there is some sleight-of-hand in the argument. Thus, despite my best efforts, this seemingly simple argument had not impressed van Dorland or Weber, who remained firmly in the Wahl-Ammann camp.
I classified three families of problem in the multiproxy literature:
1) the specific and somewhat exotic problems of MBH98 – bristlecones, biased PC methodology and failed verification statistics;
2) the “divergence” problem in which proxies didn’t work in the last half of the 20th century;
3) cherry picking and data snooping; in which the proxies were used over and over and the selection was biased, showing the particular impact of the Yamal series.
Afterwards, I talked to Weber, van Dorland and de Laat at some length, with Weber being the point person.
On the Divergence Problem – they were “working on it”. Weber denied that the Divergence Problem applied to ring widths – here she was simply wrong. The point is buried pretty deeply in the literature – there’s one graphic in passing in Briffa et al 1998, but the graphic exists and was one of the graphics that I presented. As to the mismatch between proxies and temperature, she thought that wasn’t a problem – we had a temperature record in the 20th century and could use it; for earlier periods, we could use the “proxies”.
On the selection of proxies – Weber said that they used the proxies that were “available”. I offered to bet 500 Euros that their CPD submission would use the Yamal series, rather than the equally “available” Polar Urals. She didn’t take the bet. This is a big deal in my opinion – results in these little 10-series subsets, such as their forthcoming CPD submission – are highly sensitive to picking. The issue had been raised last spring by Marcel Crok, but didn’t seem to have registered.
We talked about bristlecones/foxtails. She argued that they were “necessary” to represent an important region that would otherwise be unrepresented. They didn’t seem to care about the statement by the NAS panel that they should be “avoided” in temperature reconstructions.
We talked for a while about “data snooping” as the term is used in economics – if you know what the series look like as a result of a literature search, including searches by prior authors, then usual statistical tests have no meaning. She either disagreed with this point or didn’t understand it – she definitely didn’t agree with it.
We talked about failure of verification statistics. Weber said that Juckes was their statistics guy; he knew about r2 and RE, while she wasn’t much interested in statistics.
It’s pretty easy to predict what their CPD submission will look like. I’ll bet that it has almost exactly the same proxy network as Osborn and Briffa 2006. They will argue that they can get a HS from this network without using PC methods; ergo, everything is fine in Team-world. Anyway, we shall see.
Afterwards, Marcel and I travelled back to Amsterdam, where I was interviewed by a Belgian newspaper; then a very pleasant dinner with Marcel and some of his friends and family. Then off to the Free University. When I arrived at the university, there was a sign “Lezing McIntyre”‘?, together with a photographer from the university newspaper. It was like being a very minor celebrity.
I’ve posted up my powerpoint here for the Free University presentation, which is pretty much the same as the Stockholm presentation and is what I should have presented at KNMI, where I tried for too much detail.
This lecture was very well attended with about 120-140 people. A couple of people snickered loudly when they heard that Mann’s verification r2 was nearly zero. I got a lot of questions, but the questions were mostly about global warming and politics rather than proxies or statistics. I realize that this somewhat comes with the territory, but generally I do not attempt to provide opinions on broader issues.
Afterwards, a lot of people came to talk – it was particularly nice to talk to the friendly faces of the two Hanses and Ferdinand. Some young students wanted to have their picture taken with me – my daughter would have rolled her eyes at this.
Through the trip, I stayed in a very pleasant small hotel overlooking a park arranged by NWT. Amsterdam is a very nice city to visit; it was fun being a small celebrity; the trip to the lion’s den was stimulating and Marcel Crok was a terrific host.