Bishop Hill Self-analysis
Dec 4, 2008 Climate For followers of the climate change debate and the IPCC process, the fact that IPCC reviews are conducted by the same people who wrote the papers in the first place is not news - Michael Mann was of course famously a lead author on the paleoclimate chapter of the IPCC 3rd assessment report, which, if I recall correctly, managed to include a picture of the Hockey Stick no less than six times.
There is an interesting post up today at Peer-to-Peer, a blog run by the Nature group, and authored by Maxine Clark, the executive editor of that organ.
Nature's 27 November issue (456, 432; 2008) carries a News story about the planned retirement of the editor of a theoretical-physics journal, who was facing growing criticism that he used its pages to publish numerous papers written by himself.
According to Nature, 5 of the 36 papers in the December issue of Chaos, Solitons and Fractals alone were written by its editor-in-chief, Mohamed El Naschie, making nearly 60 papers written or coauthored by him in the journal this year. Most scientists contacted by Nature said that El Naschie's papers tend to be of poor quality, although a few find his ideas original and interesting.
Nature has played a less than stellar part in the global warming debate, refusing to adhere to their own policies on data availability, and suppressing views that do not adhere to the required view. Here is a chance for them to redeem themselves though - I wait, in hope rather than any great expectation - for an article from them demanding resolution to the similar problems that beset the world of climatology.
Reader Comments (9)
FIrst of all, thank you for a splendid blog, especially thanks for 'Caspar and the Jesus paper'.
I'm fighting the good fight in a discussion forum at a nationwide Danish newspaper and I've presented the critique you outlined in the above mentioned post. However, it seems I've run into someone who actually knows something about the subject, and I wonder if someone could help me out.
My interlocutor have posted a response that I'm frankly not competent to judge. His main argument is that Mann et al. as of September this year, has redeemed their case and refuted McIntyres critique in this paper:
Mann, M.E.; Zhang, Z., Hughes, M.K., Bradley, R.S., Miller, S.K., Rutherford, S. and Ni, F. (2008). "Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia". PNAS 105: 132520-13257
He also posits, that the question is a minor matter since several other authors have come to the same conclusions as Mann. He has posted these links as examples:
http://www.metoffice.gov.uk/research/hadleycentre/obsdata/HadCRUT3.html
http://data.giss.nasa.gov/gistemp/graphs/
http://www.aip.org/history/climate/xmillenia.htm
I realise I've only myself to thank for being in these straits since my knowledge of statistics is sparse, but still, I'd be very grateful if someone would help me with an answer, or direct me to a site that explains in plain words, how these graphs were compiled.
Now, I don't intend to engage anyone in a discussion by proxy, or try to pass myself off as an exper and I'll duly credit anyone that would lend me a hand, just as I have credited Mr. Hill for those of my arguments that I've filched from here. But I'd still be interested in a response, not the least for my own curiousitys sake.
For all of you Danish-speakers out there, the thread is here:http://www.information.dk/173667
Thanks.
If your respondent is talking about the "Tiljander proxies" (taken from lake sediment cores) see a demolition job at http://www.climateaudit.org/?p=4494 where it would seem that Mann has not only used a proxy set described by its own author as "not suitable for temperature reconstruction" but has wondrously managed to invert the graph!
I'm not sure why your correspondent has pointed you to HADCRUT and GISTEMP. These are instrumental records for the modern era. Nobody is disputing that temperatures went up at the end of the twentieth century. The issue is over the 10th to 15th centuries.
Pogo is right about Mann et al 2008. It doesn't appear to be any sounder than MBH98. The inclusion of the Tiljander sediments is ridiculous.
Bear in mind that it took six years to get to the bottom of Mann's methodology in the original Hockey Stick and there are still a few unknowns. Although he seems to have archived more data this time, the folk at ClimateAudit are struggling to understand exactly what he's done, and I shouldn't hold your breath until they get to the answers. In the meantime it is quite safe for people like the Met Office to greet his paper as some kind of vindication; they know that no one is going to demand explanations in the journal that published the paper.
For a layman's guide to the Hockey Stick affair you cannot do better than David Holland's article for Energy and Environment here:
http://homepages.tesco.net/~kate-and-david/2007/Holland(2007).pdf
Incidentally it would do no harm to post a request for help at ClimateAudit if you have not already done so. The statistics may be intimidating but they are a nice crowd, and there will probably be fellow countrymen of yours among them.
PS to my last comment. This is assuming that you have already read the Bishop's very well received synopsis of the Hockey Stick controversy which necessarily could not deal with the statistics in depth. Holland's much longer paper is able to do so in a way that is accessible to the layman.
I did read Caspar and the Jesus Paper, and since my last post, I've also read the blogentries following it and followed some of the links, which, of course, is where I should've started. Sorry about that.
The subject is rather a bit outside my venue, and there's a lot of the math and abbreviations that I don't understand, but you live and learn. Wikipedia is a great help with the math, even though a lot of it is at a rather high level of abstraction - It's not that hard to follow technically but I struggle to understand why it's done in the first place.
I have been following the Mann08 paper quite closely. I have obtained the data and studied the techniques. To put it simply, this is the single worst paper I have ever read. It is overcomplicated, the data is flawed and the statistics are unreasonable. This paper will not be part of climatology in the future.
For instance, of 1209 proxies, 90% had data chopped off the ends and new data was pasted on. The new data formed a sharp uptrend in recent years and was completely fabricated. This should kill the paper by itself.
There were an original 1357 proxy's that were accidentally posted on a government website and are difficult for Mann to remove. They contain proxies which were removed because of inconvenience.
The CPS method used to create the hockey stick creates hockey sticks from random data as well.
The CPS method used also suppresses historic signals making the recent data more prominent. CPS is incapable of extracting a known signal from data.
The data used in the creation of the HS was heavily smoothed, a process which can create the impression that it might represent temperature. It does not. This effect was not properly corrected for.
I realize all of these answers are a bit mathematical, but I assure you that in any other field this paper wouldn't get through the front door.
Here is a post I did on my blog using Mann08 on random data shaped to act like the data in Mann 08
http://noconsensus.wordpress.com/2008/10/11/will-the-real-hockey-stick-please-stand-up/
Climatology is using several math methods which are known to be bad. The big story is how do they get away with it?