At long last, the giants have begun to stir. Like the ents in the film version of J.R.R. Tolkien’s Lord of the Rings trilogy, they’ve taken their time about it. While climate war wounded sway, buckle, and fall, the giants are are so ponderous they ta…

I didn’t leave it out. It’s in the last clause of the quote.

“the PCA controversy you’re going on about is at least 5 years old, which is like a century ago in science time, you need to be open to the possibility that you believe in a widespread science conspiracy”

I believe that decentered PCA is mathematically incorrect (obviously so to a mathematician), despite it being obvious I’m still open enough to the possibility of error to ask the question, and nobody here has managed to give a mathematical explanation of why it isn’t. What am I supposed to conclude from that? In saying that PCA requires subtracting the mean of the whole dataset, not a portion of it, who exactly is claimed to be conspiring?

The obvious response is to ask are you“open to the possibility that you believe in a widespread science conspiracy”? Do you think all those mathematicians who would say centred PCA is correct are conspiring?

…which, when those readers replicate and falsify, is done through peer-review. Shocker!

I wonder if you are aware that Phil Jones says that sharing raw data and methods for independent verification is, in fact, NOT traditionally done in science, and that during the peer review process of his own papers NOBODY had ever asked for his raw data or methodology? That was reported in a story here, but I believe Jones’ testimony is also on youtube.

Did I miss it, or did you not promote the PoI episode that came out last week but didn’t feature you? Kind of in poor taste, don’t you think? Furthermore, I thought you would have liked to promote the message the interviewee was spreading, since he sounds a lot like you. He castigates the “skeptical movement” for being bad at marketing, but offers no concrete suggestions beyond “buy a marketing textbook.”

– bob

In this, the first of three special-edition epsiodes featuring D.J. Grothe, Vic Stenger discusses The New Atheism, contrasting it with the old atheism, in that it is more uncompromising in its critique of religion and God-belief. He defends the view that a soft stand on religion for the sake of science education is unacceptable, because the evils resulting from religion demand a vocal response. He describes his own history as an author critical of the paranormal and how this further fueled his atheism, contending that skepticism of the paranormal may lead to skepticism of religion. He talks about Carl Sagan and Stephen J. Gould, and their reluctance to criticize theism, and argues that sometimes, contra Sagan’s famous line, “absence of evidence is evidence of absence.” He defends making a positive statement that God does not exist—beyond a reasonable doubt—as opposed to merely stating that one lacks belief in God. He wonders if authors Susan Jacoby and Jennifer Michael Hecht should also be considered New Atheists. He describes lines of positive evidence from cosmology, physics, biology and neuroscience that he says necessary leads to a conclusion of atheism. He tells why he doesn’t think the battle over evolution education should take priority over the New Atheist’s larger war on faith, and why rationalists should not unduly seek the support of religious moderates and religious supporters of science. And he shares his optimism about the growing popularity of vocal, uncompromising atheism, especially among young people.

– The actual information text on the actual podcast. You get it by clicking on the (i) at the end.

You are obviously downplaying the role of peer-review to support your own argument. Not only that but you left out an important task of peer-review that relates to the discussion.

1. Peer-reviewers are asked to make sure the Results support the Conclusion(s). It’s completely irrelevant whether the claims are extraordinary, they just need be supported. This means reviewing the methods and all the published and supplemental data.

2. And suggest specific additional experiments or/and data that’s missing, which is very common.

Once the article is published it also must withstand the test of time. Since Climate Change is a fast-paced field, and the PCA controversy you’re going on about is at least 5 years old, which is like a century ago in science time, you need to be open to the possibility that you believe in a widespread science conspiracy.

http://www.pointofinquiry.org/michael_mann_unprecedented_attacks_on_climate_research/

and Jon, wherever you are, I asked your question on the air….

No, just “published or you’re probably a crank.” There are sooooo many unpublished cranks. I doubt many think you’ve got to be published to have a decent opinion. OTOH, it’s nice to see someone’s tether to a reality where conspiracies don’t run things.

“I’ve looked at the RealClimate stuff, and it doesn’t answer the question. ”

AFAIConcerned it’s actually covered at RC. (I did a search using just “PCA”, IIRC.) Since this whole thing is a few years old I hope you’ll understand the disinterest (perhaps general) in engaging with you over the matter now.

Remember my original question – I was curious about a new response to the responses, basically. But much like whether or not there’s any climate change worth being concerned about, Iraqi WMDs, or a real baseball team called the “Cubs”, I’ve already argued about the original matter as much as I care to.

Good to meet you as well – someone who is actually taking a point and discussing it. Don’t expect much in the way of on point refutation here though; just a lot of “it’s in the published material” is generally all one ever gets in here. Every now and then there is a decent discussion, thus I stick around, mostly just read. The “regulars” get annoyed with me quite often (apparently having obtained a degree is no longer enough to show competency in thought), but rather like to swear up and down about peer review. I dealt with enough of that in my grad program -> I was often left wondering if the authors of papers had even read half of what they cited as I sure didn’t get their take from having read it, and at best it was questionable if anything in it was really “on point” to their argument… Lots of issues with “peer review”, but I think you have to have some upper level theory course work before you understand the limitations of it (and it has overtaken everything, so the students obviously have an unrealistic expectation of its worth).

I fully understand the keeping ones head low, but I doubt many in here do. You get a lot of “if one could disprove something don’t you think they would… think of how successful and beneficial it would be to their career…” -> completely ignoring episodes such as these: http://www.probeinternational.org/files/UKVersieHenkTennekes.pdf, and http://cliffmass.blogspot.com/2009/12/climategate.html (5th paragraph explains how beneficial it was to his colleague..). The majority in here seem to still be in school, still working on their degree and thus suffer from youthful optimism and a lack of understanding how bureaucracy works -> making waves does not make one brownie points (learned that one first hand working for the government, part of my view of experience providing a very added bonus in understanding over simply being in the ivory towers…).

I feel the same way about “real climate” – interesting, but they don’t ever actually answer anything in there. Then again, it was set up to be a “talking points” type blog, so one shouldn’t expect any really challenging commentary there.

I don’t think they get that whatever level of my agreement or disagreement I will continue to ask questions. I was taught and trained to be diligently skeptical, and it has proven very beneficial to be such over the course of my life. The last thing I would want to be is a trained parrot only capable of repeating the current fad in thinking. I really do wish when one asked a question they pointed to a specific piece of the literature instead of just going “it’s all in there (somewhere…).

At any rate, it’s a pleasure to read you posts, very thought provoking and actually about science!

Delighted to meet you! There are actually an awful lot who still remember the process, but most of my colleagues keep their heads down, and don’t comment either way. We’re far from alone.

V.O.R,

“it’s a lot easier to ignore anything you don’t feel like responding to.”

What, you mean like my request to provide a mathematical justification for decentered PCA? The problem is, I’ve looked at the RealClimate stuff, and it doesn’t answer the question. It talks in circles around it and at various tangents, but it doesn’t answer the question because it can’t. A simpler example: you calculate the variance of a set of numbers by subtracting the mean, squaring each value, and then averaging. Can you calculate the variance by subtracting the mean of a small subset of the data? Is that right or wrong? Is there any way it could be right? Or can you argue that it doesn’t matter, because you get roughly the expected answer anyway?

Jinchi,

That’s the third time Rutherford et al. has been cited. See above.

The first one is more interesting though. Their argument there is that if you rotate the ‘cigar’ about it’s centre, rather than some offset point as Mann did, then the 20th century spike appears on one of the shorter axes – i.e. it was well off centre, and only the bias in the method promoted it to PC1. They then find a convenient excuse for including a number of these shorter axes, claiming it to be ‘standard’, even though the book they cite for the rule (Preisendorfer) warns against this sort of manipulation, and indeed, specifically warns that decentered PCA is invalid and incorrect. And ignoring the fact that despite their claim for it to be ‘standard’, it wasn’t what Mann did.

They say the Hockeystick is to be found in PC4 when the method is applied correctly as by M+M – i.e. the fourth factor in rank in explaining the variance. The effect must of course appear somewhere in the list, as the Almagre Bristlecones and their growth spurt are a real effect (albeit not a local temperature-related one). But there is a rule in statistics that you start by defining the method/test before applying it to your data. If you look at the data and then apply tests based on what you see, it messes up the significance levels and confidence intervals in an incalculable way. Coming up with a post-hoc excuse afterwards for including PCs 1-5 is statistical malfeasance at its finest.

There are a number of other points, they use RE instead of the more standard R2 as a test of fit (R2 is the correlation coefficient squared), possibly because R2 comes out around zero, indicating no skill. The theoretical distribution for RE can’t be calculated, and has to be determined by simulation. If you simulate with red noise, the threshold comes out far higher than the observed values. The theory of retained PCs is based on errors having independent identical Normal distributions, which does not apply to tree rings. And their alternative method without PCA still has near zero R2, and still doesn’t work without Bristlecones. Even if they were by all these means able to fix the method, it doesn’t make the original method right.

But I’m pleased that people are providing mathematical arguments regarding the problem, finally. Although the maths they provide also has to be both relevant and correct. More along those lines, please.

I’m glad someone in here remembers what the real process is (thought the journals, and those writing in them do acknowledge that being published does not mean “settled and correct”, the current crop of students don’t seem to get it…). I am really beginning to be happy I went to school 30 years ago – it seems from the discussions in here (and my experience in grad school recently) that unless one can quote something from peer review they obviously have nothing to say as the only place any real thought appears would seem to be in the journals (while they simultaneously profess they aren’t falling for the argument from authority fallacy – which I doubt any of them even know where came from…). The thought that one should be able to think for themselves (especially after having obtained the stature of holding a degree) doesn’t seem to exist in the current generation of students. The “publish or perish” has morphed into “publish or you obviously are stupid”. As quoting from peer review is the only thing they have been taught, the possibility that one doesn’t need to do such to have a valid thought seems to go over their heads and is thus simply dismissed as being unimportant. Personally, I can’t recall ever having a desire to publish (yet every paper I did in grad school was APA format -> obviously being groomed to publish…). Over the past 20 years or so this has resulted in the attitude that one must therefore not be competent enough to state an opinion (even though they have shown competency by obtaining a degree), or god help you – disagree with something which has been published.

A degree in a field used to mean one was competent to voice an opinion in that field, and while no guarantee that such commentary was without error, it was generally accepted it should not be dismissed lightly. We have in here seen the degree to which our system has been “dummed-down”, as those whom currently achieve (or are in the process of acheiving) such stature do not feel it represents any level of competency themselves.