Blogspot, you suck.

27 11 2007

hi all, sorry for lagging behind in the responses to comments.
i had a much-needed reflective Thanksgiving break. And tried to do some actual work, instead of just yacking.
And then when i opened the Pandora box again, there were plenty of comments from my good friend Anonymous, from that guy Anonymous, and also from that really obnoxious goon called Anonymous.

So i started composing a structured reply to be posted as comment, and then blogspot complained that i was using too much HTML code, so that’s it : blogspot, you officially suck. I can’t reply to comments inline, it’s a nightmare to moderate them, they look like crap compared to any WordPress blog, i can’t require guests to leave an email address so that snipers stay home, and we can’t even geek out in LaTeX.

So blogspot, you can kiss my French ass goodbye. In just a few days this blog will move to a new address, because enough is enough.

In the meanwhile here are a few answers…

Cheers !

Francois O :

i am sorry you took those words personally… if you re-read my response to your comment, you will see a “their”, not a “your” : a reflection of my limited experience in reading/talking to certain obscurantists. I never implied you were one.
I did make the mistake of imparting you some political motives. It is an error, because i don’t know them, as you point out. I was just a little annoyed that we climate scientists are always accused of political bias by virtue of being academics, (which in my experience is largely liberal). Can we stop this, everyone ?

Call me naive, but I do believe than my political opinion do not obscure and distort my scientific judgement, or at least much less than MIT’s Richard Lindzen’s when he states “AGW can’t be a real threat because that would require us to live like cavemen” (video interview for an exhibit at La Cité des Sciences et de l’Industrie). Yet, oddly enough, i haven’t seen a good skeptic get on his back. But perhaps there is one – does anyone know ?

Yes, i am ready to face the consequences of a world economy based mostly on non-fossil resources . Does it mean i will suspend my scientific training to blindly accept any alarmism ? No, and i am offended when such collusion is made.

But you’re right, François, i shouldn’t be guilty of the same sin of collusion.

Anonymous said…

Oh please, have you read realclimate lately? The sneer factor over there is off the charts, and they religiously excise nearly all dissenting comments.

As for cheap shots, those same “prominent climate scientists” routinely use the term septic or denialist (with its deliberate holocaust denialist association) to describe anyone who questions their authority. Some of us doing the questioning are very well-qualified indeed. Needless to say, such an attitude from supposedly professional scientists has very much hardened opinions against them.

As i said before, i believe the denialist term is fully justified when applied to people who bury their head in the ground against an overwhelming amount of scientific evidence. That said, RC may well censor too harshly.

Incidentally, I tend to censor posts by “anonymous” , because it’s too darn easy to be a sniper. But yours were interesting comments, so i left them in.

In particular, it reminds me of watching my own sneer factor. The problem is that blogs in general are also meant to be somewhat entertaining to keep the audience on their toes, so there is a tendency to joke about “the other side” in ways unimaginable in a science paper. As another ‘anonymous’ said, “how many people read blogs that aren’t amusing?”

More accessible and less dry than science prose, but also not as professional. You can’t have everything….

non-anon said…

you should be fighting hardest against the realclimate scientists. These guys are (almost to a man/woman) pushing a negative growth, nature over humanity political agenda, and they are using AGW alarmism to do so. They truck no criticism, nor any questioning of their authority, just like the catholic church of yore.

I think the most useful fight consists in showing a “third way” where a most balanced view is advocated and practiced. I never pretended to be the epitome of objectivity, but i can only hope that after a long enough observational period, you and other readers will place me somewhere in between extremes.

Anonymous said…

Steve McIntyre is pretty tedious. He’s been picked apart numerous times and he keeps coming.

Like a zombie.

It’s pretty amazing that he has been able to take a single peer-reviewed study and parlay it into so much attention.

How McIntyre Got Famous

Skeptics Get a Journal

But that’s what you get from the internets…..

Hey now ! This is not a blog to vent cheap shots at either side.

I deeply respect Steve McIntyre’s talent for digging through datasets, his mutinous perseverance, his incredible diligence at addressing topical climate issues (one wonders when he sleeps !), and as a dude who likes writing (can you tell ?), i respect his writing style very much. Also, he really impressed me by going to collect some date out of his own free-time and funds – that is light-years beyond what the armchair skeptic would do, and shows a genuine thirst for answering the questions, which is very commendable.

A quick browse through his posts will convince you that he’s contributed much more to climatology than a GRL article (which, as Huybers showed, has its own problems).

So while it is no measure of scientific quality than to be highly held by the editorial board of the WSJ (talk about bias !!!!) and Sen Joe Barton, i suspect the situation would be very different if “mainstream climatology” (to which i now belong…) had given him the attention he deserves, instead of constantly dismissing his comments.

Of course, it would help if he chose the “normal” avenues of science, with a slightly less offensive tone, but that’s a style i personally enjoy. It’s not for the weak at heart… neither is this blog, obviously 😉

Anonymous said…

What is going to happen if the earth cools as CO2 continues to rise? Science needs a champion, now.

Oh, brave Anonymous, i see a role for a luminary like you in our fast warming world !

Wow, TCO, what prolific commenting !

I really appreciate your comments as you seem to know the issues quite well, but again, this is not a McIntyre-bashing blog. I think the best test of whether he’s right and wrong, and on which topics, will come from the harsh light of confrontation (with gloves on). But this requires paleoclimatologists to engage in a fair debate with him – one whose rules are not dictacted by ClimateAudit , RealClimate, or yours truly of course.

I really want to invite him to speak at Georgia Tech and see if he has anything of substance to say, and can convey it in a clear manner. This might pave the way for a more fruitful discussion. I’ll keep you posted…

Gianni, as i have said, data availability is absolutely fundamental to the progress of this field. I never asked for a “pass”, just a little more understanding, because i think few fields feature datasets that require so much personal time, effort and contact with the elements. I may be wrong. Anyone has examples ?

Now this :

Nobody would care about the antics of paleoclimatologist if it were not for the fact that many of them want to change society back into some sort of hunter gather community. Sorry, forget about the hunter bit, we probably would not be allowed to eat the animals anyway!

I am sorry to say, this is plain and aggressive ignorance. First, most paleoclimatologists stay quite clear of advocating policy choices. Please show me a study that would demonstrate the opposite. Second, i do believe there is a middle ground between industrialism gone wrong and pre-history. It’s called progress. It’s not a middle-ground, actually, it’s a different dimension altogether. You could try reading this for a more informed perspective.

Thirdly, as far a vegetarianism is concerned, you should probably read what an obscure physicist called Albert E. had to say about it…

Anonymous said.

El Niño

I apologise for setting such a bad example to ‘the youth’ by posting anonymously, but of course this does not in any way effect what I said, which was that the integrity of an argument can be evaluated by the way in which it is formulated and expressed. Only sound, fallacy free, arguments are likely to persuade AGW sceptics to join the ranks of the orthodox. And sceptics do have to be persuaded, they are unlikely to be coerced by name calling, abuse, or peer pressure.

True. Yet, if i am risking by public persona in the arena, i think you should show the same elementary courage.

In your response, you have impugned my courage, suggested that I am a corrupter of the young and managed to work in the ‘flat earther’ insult too. Then, as if one fallacy (ad hominem attack) was not enough, you cite ‘the expertise of ~450 authors’ of the IPCC, a blatant appeal to authority. Unfortunately you have not addressed the substance of my comment, which is a pity because I would have been interested to hear your views.

Well, yeah, i was poking a little hard because i do despise snipers. I have re-read your comment and still do not find matter there to address – except that i am arrogant. Are you asking for explanations ? Do you want to see a copy of my French passport 😉 No, seriously, if you want me to address something in particular, please rephrase it and i will do my best to address it. As it stands I have not gotten your point.

You say :
In the real world, outside academia, it is frequently necessary to act on matters of importance without having expert knowledge. And knowledge does not confer infallibility on anyone; not even climate scientists.

In my opinion, an “expert” is only as good as their ability to convey their knowledge. So let me re-try again to convey my view : while climate orthodoxy does sometimes does a poor job of recognizing holes in their own arguments, it is a VERY different thing from the pure disinformation campaign run by some skeptics.

No, we don’t know everything about the Earth’s climate. And we should certainly be more humble about it. But we know enough to say that physical and biological systems on Earth are undergoing enormous changes , that these changes are mostly caused by human activities ; at current per-capita emission rates, future anthropogenic global warming is thus a real and serious threat, and a wide spectrum of climate and economical models concur to show if we do nothing the consequences will likely be disastrous for our way of life and our children’s. That’s my appeal to ‘authority’.

One cannot always act with ‘expert’ and complete knowledge, but wouldn’t you agree that good decision-makers do refer to experts before taking action ? Because the issue is so huge, there are many experts worldwide – and the fact that they can reach a consensus is pretty powerful thing, methinks.

One can search for balance on political issues all their life – that is all fine. But this is science, and their comes point where the frenetic quest for ‘an informed opinion’ turns from healthy skepticism to blind denial. We may not agree on the location of that boundary, so i would be curious to hear where you place it.

What we, as a global community, choose to do as a response to AGW is (or should be !) a matter of debate : and that’s where economics and politics enter. But the basic tenets of the science are hard to dispute unless one wants to step pretty far out of the realm of logic. Is this a point you want to discuss ?

Perhaps i was excessive in saying that ‘most’ of the Opposition is made of obscurantists. I would be thrilled to see proof that they are made of rational, healthy skeptics who simply have not been put in presence of the overwhelming mound of evidence. But i am reminded every day of how many obscurantists there are in the media, and i don’t think i could ever fight them hard enough – there is indeed too much at stake.
Perhaps i should change strategy, though, and your comment will encourage me to think about it.

What would it take to convince YOU, dear Anonymous ?

PS : i did not get the Eli Rabbett joke . Call me silly.


An open letter to Craig Loehle

26 11 2007
Dear Craig,
I wanted to explain the position of wariness i have publicly taken on a potential collaboration with you.

First, i should have thanked you for offering it, because that implies that you believe i could contribute something useful. Quite a few people know vastly more about this subject – but it could also true that they might not be so open to collaboration outside of the tried “teams”. Hence my inexperience comes as both a blessing and a curse, but i am honored that you would even consider a collaboration with me – especially after some rather unsparing critiques. This alone is reason enough to respect you.

I have been prudent, however, to get involved in collaboration, as i wanted to be sure that you are after the answer to the old question “Was the Medieval Warm Period (MWP) a global signal and was it warmer than now ?” – and not just another dissenting publication to give fuel to the AGW-denying side, throwing away the standards of scientific publications that you seem to have upheld during much of your career (if i am to judge from a quick Web Of Science search, and browsing through a few papers).

You seem like a very creative scientist and i would never mean to downplay the contributions you have made to applied mathematics. The issue is, as far as i could judge from that one Energy & Environment article, you did not seem genuine and serious about answering the aforementioned question. This, some flamboyant prose notwithstanding, is the essence of my review.

Also, you referred in the 2007 article to a discussion of the MWP in “Loehle (2006)”, whereas upon closer examination, the paper lists only 2 references of yours : one in 2004, one in 2005….

– Loehle, C., (2004). Using historical climate data to evaluate climate trends: issues of statistical inference. Energy & Environment, 5, pp. 1-10.

– Loehle, C., (2005). Estimating climatic timeseries from multi-site data afflicted with dating error. Mathematical Geology, 37, pp. 127-140.

I just read the latter article and found it extremely interesting. I fully agree that the field of paleoclimatology has failed to taken dating uncertainties into explicit account (p137, top line). This is something i have recently started to work on, and yours is exactly the kind of contribution that could change this. The last paragraph, however, left me quite dumbfounded :

it is not sufficient to simply average historical data to produce a global or hemispheric timeseries, because dating error afflicts virtually all extant pre-instrumental reconstructions. There are two options available for obtaining statistically valid global or hemispheric timeseries. If better dating methods can be developed to reduce dating errors in proxy records, then simple averaging of series is valid. Given the many sources of dating error, this is a challenge. If, on the other hand, multiple series can be estimated, the estimation methods developed in this paper can be applied to identify trends and cycles in the historical record, even with dating errors.

(p 139)

So, if “it is not sufficient to simply average historical data to produce a global or hemispheric timeseries”, why did you do so in the E&E article ? And why didn’t you apply the two-stage nonlinear estimation technique you describe in the Mathematical Geology article, since it was so readily available to you ?

Have i been unfair to you while overly indulgent with my colleagues ? I have been accused at and on this blog of not taking a “hard look in the mirror” – a fair criticism i mulled over this during the Thanksgiving break. As i’ve stated elsewhere, my criteria as a reviewer have been :

1) Is the result or approach original ? Does it recognize prior scholarly work on the topic ?
2) is the methodology described with enough detail ?
3) are all important choices substantiated by reference or discussion ?
4) are the uncertainties appropriately discussed ?
5) are the conclusions warranted by the analysis ?

(these would undergo minor adjustments according to the field of study, e.g. paleoclimate vs. recent climate vs. climate modeling. They are by no means universal, and i welcome suggestions from other adepts of peer-review to refine or correct them.)

Be that as it may ; in the case of you paper, i would answer by :

1) yes

2) not for me
3) somewhat (yes for excluding tree-rings, no for why certain other problematic proxies were retained)
4) no
5) no

So that would lead me to ask for major revisions, or plainly reject the manuscript if i felt that the author were not of good faith. As i said in the review, a few other minor flaws hinted to the latter.

How would these criteria apply to other published reconstructions ? Let’s take the canonical “Team” global reconstructions (Mann, Bradley and Hughes, [98/99] ; Esper et al. [2002] ; Moberg [2005], Hegerl et al 2007), that i have read in sufficient detail. I state here, that while all of them have their own limitations, the same criteria i applied to your article would lead me to accept them as valid contributions to paleoclimatology – but obviously not as the Climate Gospel. In particular, much remains to be done to address uncertainties in time and temperature (X and Y, so to speak) and estimate error bars in a manner that truthfully reflects the uncertainty in the reconstructed temperatures. It is a problem in our field as a whole, one where i can only hope to make some advances myself. I never demanded you to miraculously solve all the problems of paleoclimatology in one fell-swoop ; i merely demanded proof that the basic homework had been done. Since your paper gave such a displeasing impression of the opposite, i labeled it as “pseudo-scientific gibberish”. This seemed to get quite a few people angry at ClimateAudit (although this is not a very hard thing to do ;-), so I re-iterate my definition :

Is pseudo-scientific any text or speech that wears the attributes of science while lacking the necessary rigor in the essential fulcrums of its reasoning.

and stand by the claim that the adjective applies to the E&E manuscript in its present form. I concede that “gibberish” was a somewhat excessive substantive, and i apologize for this unnecessary strike.

So, after this clarification, what do we do ? If you are ready to meet and address these issues in good faith, i would be more than happy to help in whichever little way that i can. I do believe that much is to be gained from a insightful application of mathematics to climate proxies, and would be thrilled to take part in it if our objectives are common. If you are still interested, you know where to find me.

Of course, you are perfectly free to ignore this call – after all this is only a blog and there are more important things in life.

Julien Emile-Geay

The Loehle Reconstruction

19 11 2007
So this is my Sunday-night review, hopefully a more peaceful one than my Friday outburst on Climate Audit. I have re-read the paper and don’t have many more nice things to say about it… But hopefully i have weeded out the superfluous – including the “aggravated tone” . There might still be some irony left : apologies in advance.
I have refrained from reading CA comments that followed by friday-evening post (221), to stay on point. Comments to the answers to the comments to the questions will come in due time (i have a busy week coming up, and have unchained quite a firestorm that i cannot tackle tonight…).

Before we start, however, I have a few disclaimers to make :

  • I am conducting this review alone. This is unrequested work, i am only doing it for the defense of my own scientific conviction and to share it with other readers, some of which have little background on the subject. Needless to say, the form would be vastly different if this were a review carried out for a scientific journal. However, my angle on it is : does Loehle’s reconstruction, meet the basic criteria that i would apply to a review, were i asked to be a referee ? Anyone is free to disagree – and i am looking forward to insightful comments from statisticians.
  • Since the issue has started to appear on this CA thread, let me be perfectly clear. I am not here to defend previous work : the sole focus of this review is Loehle’s article. I am a newcormer to this game, having entered the wonderfully charged world of paleoclimate reconstructions less than a year ago. As such, i do not pretend to have inoxydizable expertise on all recontrusctions to date, much less on all of ClimateAudit’s blogposts. Hence, please do not ask me to justify so-and-so’s methods. Loehle comes as a challenger in this game, and i believe it is the job of the underdog to do at least as well as the Establishment he criticizes. I will accept no excuse of the type :”this had not be done in the usual reconstruction” if they are demonstratedly doable in the case of this simple method (cf error bars). McIntyre is well-founded when he says that much of my criticisms would apply to some previous work, none of which have i ever pretended to defend.
  • I am not emphatically not here on behalf of RealClimate, the IPCC, GaTech and certainly not here to defend Dr Mann. I am entitled to the independence of my views and refer to none but my own education, judgment, and bibliography. Dr Mann, on the other hand, is entitled to the defense of his own work, has done so with relentless (and arguably, successful) effort over the past 9 years, and is an equally independent scientist who can fend for himself. My own opinion on the MBH99 reconstruction ? I wouldn’t bet the family farm that “1998 was the warmest year in at least a millennium”, but i agree with the NAS panel when they find that , “with a high level of confidence […] Global mean surface temperature was higher during the last few decades of the 20th century than during any comparable period during the preceding four centuries”. Ditto that is it is plausible that “The Northern Hemisphere was warmer during the last few decades of the 20th century than during any comparable period over the preceding millennium”.

    Mann’s publication record speaks for itself, he and collaborators like Scott Rutherford have undertaken very extensive re-workings of the MBH98/99 algorithm, albeit not necessarily gracefully – in CA’s eyes. I wholeheartedly agree that climate science is lagging behind other fields in terms of providing open access to data and methods, and Steve McIntyre’s efforts are much needed in improving these standards. Nonetheless, i find CA-dwellers a little antiquated in their constant re-hashing of MBH98 criticisms. They would be well inspired to direct them at his most recent work if they so wish, rather than beating horses dead in 1998 or 1999. While it is true that MBH98 is not the panacea of climate reconstructions, it would be reductionist to corner all of “Team” into one article and ignore almost a decade of subsequent work. Since CA readers get understandably upset when i lump them together with climate obscurantists, they should lend a sympathetic hear to the statement that not every climate scientist is guilty of pensée unique.

Review of Loehle (2007).

The article comes from Craig Loehle (a PhD in Mathematical Ecology with a rather freshly-discovered interest in climate research) , and published in the infamous “Energy & Environment“, a peer-reviewed journal that recently emerged as the number one printing device for climate obscurantism. Indeed, said ‘peers’ do not seem to know much about climate. Be that as it may : let’s go beyond appearances and give the paper an honest read : Loehle could be a revolutionary mind, whose deep mathematical insight will cure many of the ailments that have henceforth plagued the efforts of many a climate scientist – who, owing to CA, are allegedly ignorant in statistics.

We start by an extensive introduction that argues for the inability of tree-rings to record any temperature signal on the period of interest, and is decently informed. While it would be excessive to throw out just ANY tree-ring series (though they had issues with strip-bark trees, i don’t believe the NAS panel recommended the incineration of the entire dendroclimatological literature), the point is well taken : in light of the many factors that influence tree-ring growth over long periods, it is certainly a valid “What if ?” experiment to produce a reconstruction free of such data. Since the author acknowledges that it is not the first (Moberg [2005] and Viau et al [2006] have already done similar things) , we are eagerly awaiting what original statistical techniques will be presented here if the author is to arrive at a substantially different conclusion.

Eyebrows start rising when the only references given to support the existence of a “Medieval Warm Period” (MWP) are from the author himself (Loehle 2006), and Soon and Baliunas (2003), which has been thoroughly debunked by RealClimate colleagues (see Myth #2). For those not so versed in blog wars, The MWP is a favorite of global-warming denialists, because if you coax the data into showing a warm enough early millennium, you can negate all of the IPCC’s work : it’s super duper cool.
Unfortunately, there is ample evidence that the so-called Medieval Warm Period was far from global : see for instance the NAS report (North et al, 2006, chapter 11 and references therein). There is, however, great interest in understanding why it was warm in Europe or dry in the US South West and central America, and seemingly cool in the eastern tropical Pacific (cf Graham, 2006), so let’s read on.

METHODS : The section is startlingly short. 18 proxy timeseries are selected on the grounds that : a) they are available for 2000 years b) they are not tree-rings. A decent case is made that one should not worry too much about dating uncertainties. Fair enough. What next ? Data are smoothed, standardized, and… averaged. Period.

I had to read the article 3 times (re-downlading it just in case i had gotten a faulty version the first time) to convince myself that i wasn’t dreaming. All subsequent figures show the arithmetic mean of 17 or 18 series, as if they all recorded local temperature with the same accuracy, and were representative of the same geographical area.

Proxy temperature relationship

Since the article’s title mentions a “global temperature reconstruction”, one would expect two fundamental aspects to be discussed . 1) these are reliable temperature proxies ; 2) they are representative of a global average. In that light, i expected the merits of said proxies as paleothermometers to be at least brushed upon. There are only 18 of them (unlike most paleoproxy studies, which can compile >200 ), so it wouldn’t break the author’s back to at least READ the papers he is citing, dig up the error estimate, and put this all into a pretty table. It’s not so clear he does *read*, however, otherwise he wouldn’t have retrieved a “Borehole 18O temperature” from Dahl-Jensen et al. [1998], just a borehole temperature inversion.

This is a very different situation from usual multiproxy studies which use sophisticated methods to ensure that a proxy’s weight in the final result reflects its ability to record some variance in the temperature field (whether local or not). While there is merit in exploring a bare bones approach (arithmetic mean), it then becomes indispensable to demonstrate that each proxy is : a) a temperature proxy (not a salinity one…). b) a good one at that.

At first glance, a) is dubious for the Holmgren and Keigwin timeseries (that’s at first glance… i need to dig more), and b) can usually be assessed from the authors’ error analysis. If it is not, then the author should conduct his own, or drop the use of such proxy.
Once again, such care would not be required when a climate-field-reconstruction or “composite-plus-scale” approach is employed, as the proxy’s ability to record temperature is implicit in the calibration therein. Since the author effectively treats the proxies are perfect thermometers (which is conceptually acceptable as long as it is explicitly justified), the lack of this discussion is unforgivable, and in my book, constitutes grounds for rejection any day of the week.

Error propagation analysis

This part is usually immensely complicated in the case of non-linear estimators, but it should be a piece of cake here. Since the proxies are so concisely described (i agree that a map would have been nice – apparently it didn’t take S. McIntyre very long to make one), it comes as no surprise that the final result is utterly devoid of error bars.
Instead, the author chooses a jacknife analysis, which in my view only speaks to the relative importance of each proxy in the final results. Imagine all proxies had a standard error of 2.5 degrees with the actual temperature : this analysis would say nothing about the accuracy of the mean.

Let’s be more constructive than in my original CA post : there are several possible approaches. For instance, one could assemble a vector of proxy errors, and assume the temperature proxies are iid and Gaussian, which is quite reasonable. It would not take a PhD in mathematics to prove that the arithmetic mean is also a Gaussian random variable with a standard deviation that is the L2-norm of the sigma vector (divided by the number of series). This is rather simple-minded, but since the approach is deliberately simple, it would be consistent with this framework. There maybe more elaborate ways, as discussed by Hu McCullough here.

In any case, it is unacceptable to make the quantitative claim that the data ”would indeed seem to show the MWP to be warmer than the late 20th century” , “by about 0.3 degrees. This number is worthless without an error bar, or at least an insightful discussion of uncertainty.
Rejection again, sunday or friday.

Reconstruction skill.

Again, impressive concision ! Where are the CE, RE, and most importantly R-squared statistics that are so dear to ClimateAuditers when used by the Team ? How are we supposed to guess whether the reconstruction has any skill ? (skill, by the way, is a ubiquitous term in the numerical weather and climate forecasting literature. It is intuitive enough, but if statisticians need a more statistical term, i can try and dig one up over the next few days). In his original response, Loehle argues that these statistics are irrelevant because he does not have a model. This is false, as pointed out by bender, and myself. Despite claims of using a “simple mean”, the author’s approach is effectively a multivariate regression. Indeed, each of the proxies was calibrated against temperature using such regression methods, usually linear, but sometimes non-linear (Mg/Ca ratios depend exponentially on seawater temperature, for instance). So by doing even a simple average, the author is effectively using a statistical model, and is therefore not exempt from the verification exercise.

(incidentally, i regret that bender seems to believe i have been plagiarizing his ideas. I was responding to earlier comments when he posted his and did not see them until after i had submitted mine – an unfortunate consequence of the high traffic at CA… This convergence does, however, suggest we have more in common than what superficial disputes would suggest, so perhaps one day we’ll have real dialogue)

Minor comments :

– I could not find a reference for “simple mean” (p1053). It may be a novel contribution to the mathematical literature – which had heretofore used “arithmetic mean”. I only point this out since CA statisticians seem always eager to correct climatologists on their improper use of statistical terminology. While i am genuinely eager to be educated in statistics, i wish the same standards applied to everyone.

– I believe it is the first time i read ‘I believe’ in a scientific paper (it’s different in politics), and it is there 3 times in the discussion. Hmmmmm…

– R. Villabala does not appear to have any publications on the Medieval Warm Period. Ricardo Villalba, other other hand, does. (the error is present in the text and reference list). This reinforces the feeling that the basic homework really hasn’t been done.

In summary, this article is a poorly-described compilation of proxy data, with a conciseness in methodology that borders on farce. In the present form , it is unacceptable in any scientific journal that i am aware of. Though the approach is conceptually useful, it is not novel : the author himself acknowledges that Moberg (2005) and Viau (2006) have left out tree-rings from some parts of their reconstruction before. So what is new here ? It can only be the methodology. We have shown that its elliptic nature is naive at best, misleading at worse. Even with all the good will in the world, it is hard to grant the author the benefit of the doubt, given how loosely he handles his references and prose : this simply is not credible work. The author’s argument that his “strategy in writing this was to make it as short as possible to avoid complications during review” is distinctly unconvincing. Why not, then, bypass the whole ‘methods’ section, and simply give us a curve without any explanation ? Brevity is the soul of wit, yes – but when crucial information is missing, this “science” has an odd scent of disinformation.

I am glad to see that a healthy debate has now engaged on CA and that Steve McIntyre has undertaken a serious audit of this study (e.g. here and here). Already, some of my question regarding spatial sampling have been admirably addressed, and though it should have been the author’s job to do this before submission, the only thing that matters here is that the question be answered somehow.

I hope this debate will bring Craig Loehle to produce a scientifically-acceptable reconstruction – one that meets our basic field’s criteria for publication. He would otherwise condemn himself to sub-standard journals like Energy & Environment, ensuring that they are invisible to climate scientists – for good reason.

Let’s audit Climate Audit !

19 11 2007

Hi kids ! It’s been an interesting week-end …

On thursday, Nov 15th, i was notified by the Chair of my department, Dr Judith Curry, that a new reconstruction of global temperature had been published (Loehle,2007), and that a thread on it had been started at

For those not involved in blog wars, the latter is an interesting blog animated by Steve McIntyre, a climate skeptic with merciless talent for tearing apart a dataset. The word on the street is (some readers may want to correct me here) that McIntyre created this blog after getting frustrated that his comments were never addressed, or even posted, on .

I am a regular reader of which gathers distinguished scientists of the likes of David Archer, Stefan Rahmstorf, Ray Pierrehumbert, Gavin Schmidt and Michael Mann. These people are personally ersponsible for some of the msot exciting work in climatology, their blog has won a few awards and it is increasingly taken as authority by a number of newspapers, including my own “Le Monde” from Frogland. Blog posts on RealClimate are often entertaining, always informative, but it arguably leaves little room for heterodox climate views and it sometimes leaves the strange aftertaste that its authors are defending and selling their own research, while not explicitly acknowledging this partisanship. In particular, Michael Mann is the lead author behind the illustrious Hockey Stick graph, which is by any means a very controversial piece of research, and (RC) has proven somewhat closed to discussion on the topic – at least coming from McIntyre’s clique. Though i have not personally experienced censorship on RC, i have heard many accounts thereof. It is perfectly sensible to block global-warming-denialist trolls from spewing out insults on the forum, but not intelligent laymen who ask inconvenient questions. So quite a few people (climate scientists included) have gotten frustrated with RC as well. (today’s post about my former ministre de l’Education and his apprentice Courtillot is an absolute gem, however. Highly recommended).

On the other side of the aisle, you have Steve McIntyre and his now growing number of readers on (CA). McIntyre apparently jumped into the climate game because of some (legitimate) concerns he had with the Hockey Stick graph, and has since turned his attention to just about every piece of data that is being used in the media in climate discussions. The man seems a rather interesting fellow , with a solid math background, a painstaking attention to detail, and a devastating verve that makes his blogposts rather entertaining to read. More recently, he has deeply impressed me by undertaking some tree-ring research out of his own free time and on his own funds : there are a lot of armchair skeptics out there, but this man is doing serious work.

The strength of CA has been its openness to comments from all sides, which fostered the growth of a crowd of hard-to-please data analysts, crafting ever-more-well-posed questions and challenges to the climate science community. It is, in my view, a much needed addition to the climate debate, with expertise from various fields of mathematics, statistics and data analysis. As a scientist i wish they were taken more seriously by our community. It is natural for every society to get a little complacent and it runs the risk of resting on its laurels, unless challenged by an Opposition.

The main problem is that until recently, the Opposition was mostly represented by the despicable breed of “climate obscurantists” who have been polluting the blogosphere with a pure disinformation campaign, motivating their disparaging comments on all states of climate science by their own unwillingness to change anything about their fossil-fueled existence. These comments are always easily debunkable because they are not based on any scientific knowledge or reasoning. I would hate to be guilty of referring you to such pieces of junk, but if you want a taste , Texas Rainmaker, America’s Future or the editorials of the Wall Street Journal are quite good examples – there are unfortunately many, many more.

Hence, for a climate obscurantist, if you are with the IPCC, you are for the “climate terrorists”, no lie is above you and no punch is too low. Fortunately, CA started on very different premises. While i know little about his underlying motives, McIntyre is a very sharp fellow whose pointed questions help create a healthy debate in the field. If the IPCC consensus is as indestructible as we claim, then it must be able to weather these storms. Better still, it could be a little shaken by said storms and would emerge stronger and more legitimate.

Further, McIntyre is joined in his investigation by a vocal group of readers and commentators, some of which are quite on-point. The CA crowd is a tough one for sure : the educated skeptics in there, while decently equipped in verbal courtesy, are entirely exempt of magnanimity, and don’t let you get away with much. It’s a bit like the All Blacks rugby pack. That’s all right : i have no problem with tough players. Unfortunately, the openness and the global-warming-trashing bent of CA means that some of its participants are of the “obscurantist” breed, and are more vocal than warranted by their science credentials.

One also finds a distinct self-congratulatory tone in there, and when McIntyre makes a sneering cheap shot at a prominent climate scientist, the joke is greeted with loud cheers and pats in the back that are more reminiscent of a low-grade frat house than a respectable scientific society. This is corny at best, and most often downright tiring. Hence the somewhat playful urge of yours truly to go challenge the pack on its own turf at some opportune moment….

The opportunity materialized last thursday with the publication of a new indepdendent temperature reconstruction, one that shows a very warm “Medieval Warm Period” (aka “Medieval Climate Anomaly” because it was almost certainly not warm everywhere – more on this later), and thus poses a particular challenge to CA. Are they going to scrutinize it as ruthlessly and righteously as reconstructions that support the idea that the twentieth century warming is anomalous in the context of the past millennium ? Or are they going to congratulate the author for his “unbiased” work, pat each other in the back, and go on insulting Mann, Hansen and tutti quanti ? Does CA stand for Climate Audit or Curmudgeon Association ? Is the “skeptic” crowd even skeptical of its own children or is it a privilege reserved to mainstream climatologists ?

So on friday yours truly posted a review of it on CA. If you are curious enough to read some of comments in there (477 at the time of writing), you will find that my little post generated quite a storm.

I spent most of friday answering some of the rebuttals and other comments, and i have to say it was quite enthralling. I evidently pushed some buttons there, and undeniably some of them were quite sensitive spots. The best compliment was by Pat Keating :

You have a nice turn of phrase, and would love to read more of your critiques, preferably in the context of the AGW acolytes’ work<

So apparently i am good enough to join the Dark Side. Exciting…

Later, McIntyre started his audit and so far i am pleased to see he is not giving Loehle a free ride. This is only the beginning.

I acknowledge, however, that i wrote my CA posts in the heat of the battle, which is never a good thing. As a Kokikai Aikido practitioner, i should know better. Whenever i am given an article to review, i usually make sure to do it over a period of a few days, so that the second (or third ) reading might provide a different light and help me be more objective – particularly if i thought the article unacceptable at first read. I violated this rule on friday because i was too eager to go make a splash on CA – to make a statement that they were also being watched and that some people will prove just as picky about the Opposition’s statements than they are about the Establishment. That was quite shallow, ego-driven, and i took somewhat of a sadistic pleasure in lacerating that article – while i could be more constructive.

As my neighbor Dr Martin Luther King Jr used to say : “An eye for an eye leaves everyone blind”. As it turns out, my former NY roommate was in town this week-end and I had a fantastic time : full of laughter, Venezualian aged dark rum, frisbee-tossing in Piedmont park, rosemary pork loin roast, neighbors dropping by the dinner table all night, and late night jam sessions till we fell asleep on the instruments. Today the Sun was so intense that we could suntan on my rooftop with a good cup of tea, and i just got out of a very grounding yoga session.

So let’s chill out for a bit : true, Loehle’s article (in its present form) is a poorly-written piece of pseudo-scientific gibberish – but now that i have the watchdogs’ attention there’s no need to be barking anymore. It would be a poor tribute to a gorgeous week-end than to remain sulky.

In the following post, i will thus summarize the article in question, present the issues i have with it and respond to as many CA comments as i can before falling asleep. We’ll see where it leads…

SeisMac waves

8 11 2007

OK, it’s time to admit : i have a Mac problem. I can’t live without it.

Today, at the auspicious favor of a small explosion in my building at Georgia Tech, i had a discussion with a seismologist while waiting for the 7 fire trucks to figure out what the hell they could be doing there for so long. (It’s the South, everything takes time, here). It turns out the guy, Kevin, is also into macs, and told me about this insanely cool software called Seismac.

What i did not know, probably like a large majority of us foolish mortals, is that MacBooks have an internal sudden motion sensor, to protect the hard disk if you drop your laptop. It seems to pick up perturbations of about 0.1 kg/m/s^2, or about 1/100 of the local constant of the Earth’s gravitational acceleration.

That’s cool enough in its own right. But there’s more !
Now, as the Mac Gods would have it, the acceleration data is retrievable from Open Source software, which means that you can turn your laptop into a real-time seismometer. This for not a jack, of course, thanks to Daniel Griscom, with a little help from the National Science Foundation.

After a 2min install and a short calibration, this is what happens when i drum up the overture of Beethoven’s Fifth on my desk, 1 foot away from by beloved MacBook :

After i picked up my jaw from the floor, i had to admit, as Jerome Bonaldi used to say : “Absolutely useless, therefore rigorously indispensable”.

Call to all Californians : you can now monitor your impending seismic destruction in real time, without leaving your desk. Tsunami warnings via popup windows are a-coming. The software, however, offers no predictive capability for coffee spills.

I bow to Mac. They can have my first newborn.