Awhile back Steyn quoted a Jonathan Jones, Lecturer in Physics at Oxford University, about Mann's work. So I wrote to Dr. Jones asking for more details. Despite Jones' bluster, what I found wasn't very convincing.
Steyn quoted Jones:
The Hockey Stick is obviously wrong. Everybody knows it is obviously wrong. Climategate 2011 shows that even many of its most outspoken public defenders know it is obviously wrong. And yet it goes on being published and defended year after year.As I showed here, the hockey stick is, in fact, an elementary result of basic scientific reasoning. So I was curious about the surety of Jones' conclusions, given that I couldn't recall any papers by him on the subject.
Do I expect you to publicly denounce the Hockey Stick as obvious drivel? Well yes, that's what you should do. It is the job of scientists of integrity to expose pathological science... It is a litmus test of whether climate scientists are prepared to stand up against the bullying defenders of pathology in their midst.
On August 11th, I wrote to Jones:
Why do [you] hold this view? Why is it "obviously wrong?" The hockey stick has been reproduced several times now, some using independent mathematical techniquesand I gave him links to Tingley and Huybers, Marcott et al, and PAGES 2k.
The quotation Mr Steyn is using can be found in context at http://www.bishop-hill.net/blog/2011/12/2/tim-barnett-on-the-hockey-stick.html#comment16080991.This is clearly just a lot of hand-waving -- not sure if Steyn and his readers are familar with that scientific slang -- so I followed up to Jones:
I’m afraid that I am somewhat confused by your question, as your suggested conclusion does not follow from your premises. However I will do my best to answer.
First please note that my comments which you quote apply specifically to the Mann hockey sticks, MBH98 and MBH99. The methods underlying these reconstructions have been comprehensively debunked, most famously by Steve McIntyre; if you are unfamiliar with the story then I suggest “The Hockey Stick Illusion” by Andrew Montford as an excellent primer. Even if one accepts the underlying method of multiproxy reconstruction with effective selection of individual proxies by correlation (and like most people outside the small world of people doing such reconstructions I don't) the inclusion of "proxies" known not to be reliable temperature proxies (e.g. bristlecone pines and contaminated lake sediment series) and the use of inappropriate mathematical techniques (mostly famously decentred PCA in MBH98) renders the reconstructions useless.
These papers are methodologically bogus, and would remain methodologically bogus even if other papers were to reach similar conclusions. In so far as such papers rely on the same bogus methods then their conclusions are equally invalid; conversely papers which reach similar conclusions by different means have nothing to say in support of the bogus methods of MBH.
You mention three particular reconstructions, none of which provide any support for the methods in the MBH papers.
The Marcott 2013 multi-proxy reconstruction is most famous for the dramatic uptick which occurs at the end of the reconstruction. However it is now well known that this uptick is not robust, and is almost certainly an artefact. It is notable that this uptick does not occur in Marcott’s thesis, and I understand that the authors no longer defend this portion of the reconstruction. Once this uptick is removed there is nothing much to see unless you are advocating splicing temperature data onto proxy data.
The Pages2K 2013 reconstruction suffers from many of the same problems as the MBH reconstructions, with many datasets in common, including contaminated lake sediments and bristlecone tree ring series known to be unsuitable. Famously some of the series are used "upside down": this is a common error in papers which use selection by correlation, and a clear indication of why the method shouldn't be used. The paper adds little or nothing to the debate on MBH.
The Tingley and Huybers story is a long and complex one, and I am not sure quite which paper you are referring to, but many of their papers have used notorious “proxies” such as Mann’s PC1, the Yamal lone tree, and the most famous of the upside down contaminated lake sediment series, Tiljander's data as used by Mann. The mathematical techniques used are not as different as you suggest, and any similarities in outcome largely reflect the inclusion of the same inappropriate proxies. Once again it adds little or nothing to the debate.
I apologise that this reply is not particularly detailed, but I am currently very busy with the fallout from admissions and examining. If you want to read more about the deficiencies of the reconstructions above I suggest you take a look at McIntyre’s site, climateaudit.org, although you may find that the posts there swiftly become rather technical unless you have a strong mathematical background.
Of course I know about McIntyre & McKitrick, but I haven't seen many experts take it very seriously, especially after Wahl and Amman (2007):Jones' reply:
"Robustness of the Mann, Bradley, Hughes reconstruction of Northern Hemisphere surface temperatures: Examination of criticisms based on the nature and processing of proxy climate evidence, Eugene R. Wahl and Caspar M. Ammann, Climatic Change, November 2007, Volume 85, Issue 1-2, pp 33-69
My point about the other reconstructions -- Marcott et al, PAGES 2k, and Tingley and Huybers -- is that, if independent analyses find essentially the same result at MBH, using different mathematical techniques, how can Mann et al be so badly wrong?
I'm afraid that I don't share your take on Wahl and Amman. In fact this paper largely establishes the correctness of the McIntyre and McKitrick criticisms. In particular I draw your attention to table 1S on page 63.I found it odd that a scientist would cite a blog. The difference between peer reviewed papers published in major journals and blog posts is -- or should be -- very obvious. (Yes, that holds for this blog as much as any other. Blog posts aren't science.) They simply aren't in the same league, and it is very rare, if ever, you will ever see a scientist cite a blog post.
If you would like to read more about this it is explored in some detail in Montford's book. Or, if you don't want to read the whole book, see "Caspar and the Jesus Paper" which you can find at http://bishophill.squarespace.com/blog/2008/8/11/caspar-and-the-jesus-paper.html
Your final question was answered in detail in my previous reply, so I am confused as to why you are asking it again.
So I asked Jones about his own work on the hockey stick.
Your criticisms of all these papers -- Marcott et al, PAGES 2k, Tingley & Huybers -- strike me as shallow. They are hand-waving.I never heard back from Dr. Jones.
Where are the peer reviewed papers showing them wrong?
Have you published any papers showing them wrong?
I'm a science journalist. I'm well aware that blogs can, and do, say anything, with few, if any, consequences for being wrong. So I prefer to work from the peer reviewed literature.
Maybe asking about his own publications was a touchy subject for him. But blog-level thinking isn't good enough for professional scientists -- I can get that anywhere. The point of being a professional is to offer professional critiques. Jones did not do that. I don't see much, if any, merit in his replies.
I'm sure Steyn's readers will be impressed by whatever he writes and whomever he quotes. And Judith Curry will repeat them without question.
But as Jonathon Jones showed, at least, his criticism quoted by Steyn wasn't scientific, and wasn't impressive or convincing.
Steyn's readers got all hot and bothered by this post, but completely ignored the posts that showed how the hockey stick is an unsurprising consequence of basic physics.
I suspect most of them don't understand basic physics. Science simply isn't their interest. Instead, they are thrilled by rhetorical fluorishes and debate scoring, whether it's been the Second Iraq War or writing that sates their Islamophobia.
But as Neil deGrasse Tyson said, “The good thing about science is that it's true whether or not you believe in it.”