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Mar162013
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Bishop Hill
Bishop Hill OMG
Mar 16, 2013 Climate: MWP Climate: McIntyre McIntyre's latest post on the Marcott hockey stick is simply astonishing.
Mar 16, 2013 Climate: MWP Climate: McIntyre 
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Reader Comments (157)
Entropic Man,
In this thread you have written:
"Your links are all to opinion pieces on propoganda sites."
-Climate Audit microanalyses the data handling, as GreenSand as already pointed out.
"I'm not really interested in microanalysing the data handling of the paper."
-We can tell.
The Once and Future Doctor Marcott.
=================
Is 'Marcott style' like 'Gangnam style' only more embarrassing?
Mar 17, 2013 at 1:47 PM | Entropic man
Indeed. The Gergis/Karoly disaster and the "Loo science" discussions were very informative for the rest of us as well.
BTW, I thought earlier you had said there was nothing new in the Marcott paper, now you say it's "most informative.
I'm wondering if you're here merely for rhetorical effect or if your thought processes are truly...entropic.
Entropic Man (Mar 17 at 12:59 PM) "Oh dear, McIntyre was cherrypicking. I have just read Marcott's thesis. The graph in the thesis which McIntyre displays, Fig. 4.2a is one of a group and does not go to the present. Hence the lack of an uptick. The other three graphs in the figure, b,c, and d, all go to the present and all show the uptick."
I can't imagine how you're reading that from the graphic. All panels in Fig. 4.2 go to the same time (about 0 BP = AD1950), in fact panels c&d are the same reconstructions as a&b except "zoomed out" to include the period since ~11.3 Kya. Neither of those Marcott reconstructions show an uptick, although they do show a gradual recovery from the LIA minimum.
Mar 17, 2013 at 8:50 AM | Jon
That is the sort of evidence any layman can understand immediately.
We can perhaps all join with the Beatles in declaring:
“Isn’t it good – Norwegian Wood”
HaroldW - and as I pointed out (on page 2 of the comments) McIntyre shows 4.3a, not 4.2a and Marcott's Entropic Man would only need to read Marcott's labeling to understand what the timescale is for the further graphs.
Rather than criticising people for "relying on an appeal to an inaccurate authority" EM could try to be a bit more accurate himself.
"Are you an ocean core that is tired of your current date? Does your current date make you feel too old? Or does it make you feel too young? Try the Marcott-Shakun dating service. Ashley Madison for ocean cores. Confidentiality is guaranteed."
OUCH!
That is going to hurt! ;0)
HK (3:54 PM)
Quite so, and apologies for missing your prior post. McIntyre did indeed use figure 4.3a from the thesis, and figure C9 as well. Neither of those have upticks.
We will have to see what EM has to say about why he came to the conclusion he did.
I can only assume that EM did not bother to read the captions in Marcott's thesis, nor did he particularly look at the graphs. The only uptick and the only data shown "to present" in the 4.2 figures are the Mann08 that extends ~60 years beyond the end of Marcott's reconstruction. In the thesis figure 4.2 all reconstruction curves end on a downtick. In the thesis figure 4.3 all reconstruction curves end on a downtick.
I'll take my blog commentary based on factual statements, not counter-factual, thank you very much.
you're here merely for rhetorical effect
Mar 17, 2013 at 3:17 PM | John M
Got it in one. How many of you have now read Marcott's thesis who had previously only taken McIntyre's word for it?
Mr. Random-thought,
My comment has nothing to do with having read the thesis or not having read it.
My comment pertains to what you have said.
But while we're at it, based on your past behavior, frankly, I don't think you've every actually read anything yourself.
You seem to operate by a series of random links you keep in a list and comments you've gleaned from other blogs.
Why are Skepticalscience and Realclimate keeping quiet? Where is the Climate Science Rapid Response Team?
Answer: They are afraid. After gettting their ass handed to them from sticking their neck out, as in the case of the Glieck Fraud and the Gergis debacle. The macrophage squad wants to see how deep the gash is, before arriving.
Its almost been two weeks now. Quite the acquired immunodeficiency, one could easily say. After all, the primary function of these blogs is to spring to the defense of climate science.
Shub,
Yes indeed, Mann had already proved he could not assess the problems with the paper (with his early comments), and it is a reasonable hunch that RC and SkS need to know how bad the situation is before they try to pick their fall-back position.
Theo - my 1:14am was making the point that EM confirms above.
He is a troll not interested in the substance of the matter at hand. His objective is to get tempers high and divert attention from the issues which many are pointing out with the Marcott paper and its presentation in the MSM - check his introductory remark on this thread.
In the comments preceeding my 1:14am, EM made comments such as "there ought to be references" blah blah blah and my comment was a link to show the source data is actually available and a moment's google away. When he is caught out out, for example over the actual figures referenced in Marcott's thesis, he shape shifts from the role of "interested scientist" to "agent provocateur."
That is why IMO it is a waste of time to engage him - his interest is confusion rather than clarification. As far as motivation for this type of trolling goes, I do wonder if one aspect it to pollute critical threads with nonsense so that if a new enquirer drops by, as Earle Williams points out above, they will find it hard to discern fact from fiction. This has happened on similar past threads here and elsewhere.
It is in this context that I find it so refreshing when a qualified observer such as Paul Matthews is prepared to put his specific criticisms on the public record.
According to Wikipedia http://en.wikipedia.org/wiki/Jude_the_Entropic_Man
Teleconnections, anyone?
Shub, yes, the silence speaks volumes.
Even enthusiastic warmists Nick Stokes and William Connolley don't like the paper!
n b y thanks. Just wish I wasn't the only one. Subtle hint to academic lurkers.
...as if Connolley's opinions matter, other than to himself and to the league of petty scientists such as Eli Rabett and Grant Foster...they talk amongst themselves and seem to have decreasing influence. For one thing, look at Rabett's interventions on the recent thread on Annan's blog about uniform priors...he was trying strenuousloy to shift the argument away from the conclusion that climate sensitivity is low...sadly no one took him seriously. but, then again, why should they?
I just left a comment to Revkin's blog:
Dear Mr. Revkin,
you may not remember me, but last summer after your endorsement of the open review, in a relation to the Gergis et al. incident,
I wrote you a comment.
http://dotearth.blogs.nytimes.com/2012/06/11/australian-warming-hockey-sticks-and-open-review/?comments#permid=10
As you may have noticed, we are, only nine months later, in a middle of a new "incident" as predicted. Again, the paper was accepted without the code, which could have helped the reviewers to spot the very "non-robust" "upticks" in the reconstructions. Or,
at least, the code would have made the work of external auditors like Steve McIntyre much easier. Not only the authors did not
provide the code for the current paper, they also failed to provide, against promises, the code for their Nature paper (2012).
Of course, we do not have much influence how certain climate scientists and journal editors behave, or how Science and Nature
enforce their own rules. But notice that I ended my comment with a suggestions to journalists.
Indeed, I now see that you had contacted several people regarding the paper. Do you think asking the authors to describe their own work is a kind of question I meant? Do you think asking a comment from a person, whose work is essentially endorsed, is a good idea? Did it even cross your mind to also ask a comment from a person (like Mr. McIntyre) who might have something critical to say about the paper? Finally, did you ask the authors for the code and data?
Brgs, Jean S
Paul - sadly I think it is clear subtle hints are not going to be enough to instill some backbone into the ranks of academics who let this nonsense pass. I'm tempted to say they need "naming and shaming"...
FWIW - if any youngster I know is looking at doing maths, your involvement in these forums means I'll suggest they take a serious look at Nottingham - so I hope you are not just a lone voice in the dept!!
********
Jean S - good luck with that!!
Jean S...your campaign is important - it seems as if the mainstream has now delegated peer review to climate audit....and it is important that that fact is acknowledged in the mass media - so every press release needs to say that "we await confirmation by climate audit of these results"
Mar 17, 2013 at 6:42 PM | not banned yet
How polite of you to bring me up to speed. Thank you. As regards EM, my learning curve was very short. It seems that I skip EM posts automatically or instinctively.
HK
You are right, it was 4.3a. My apologies
I notice nobody has addressed McIntyre's cherrypick of ignoring 4.2b, c, and d; or 4.3e and f.
Nor have any of you addressed the overall shape of the Holocene graph or refuted Mann's point that, on the basis of the station temperature and satellite record, we are passing into temperatures not previously detected in this interstadial.
Say No To Fearmongers.
Thank you, SNF. I never thought to google my nom de plume! :-)
Say No To Fearmongers
A more realistic portrayal of my situation would be playing Cassandra to your King Priam. Remember what happened to the Trojans.
Thinks he is impressive by using terms like "interstadial", but doesn't know what they mean.
Says "none of you have refuted the point that, on the basis of records going back 160 and 40 years, we are passing into temperatures not previously detected in the last 10,000-12,000 years."
Like I said, dumb as a box of rocks.
"I notice nobody has addressed McIntyre's cherrypick of ignoring 4.2b, c, and d; or 4.3e and f."
It seems that Entropic's reading skills are on a par with hengist....it is all too clear that he really is a teacher. Sadly.
Entropic
"Nor have any of you addressed the overall shape of the Holocene graph or refuted Mann's point that, on the basis of the station temperature and satellite record, we are passing into temperatures not previously detected in this interstadial."
-----------------------------------------------------------------
You are comparing different things. The reconstruction is flattened due to
1. low frequency data
2. errors in dating
3. non temperature influences
Guess how the instrumental temperature record would look like
with a 300 years resolution,
dating errors leading to averaging of 1912 with 2003 temperatures or whatever,
and station siting and quality.not looked after by anyone for centuries.
That makes rapid variations undetectable. Any opinion about them is nothing but hot air.
Better reconstructions show present temperatures below the Medieval Warm Period, despite above reasons for flattening apply for those as well, so they may have been significantly higher then on shorter time scales.
If you are interested in real science, I would have a look at Uni Heidelberg Mangini's high quality high resolution speleotheme data. His conclusions are
- high quality data locally shows similar (or even higher) fast variation in the past. Neither speed nor amplitude are uncommon.
- high quality data is synchronous in various places around the world.
EM, I see you more as a Biblical character than a beautiful prophetess. Genesis 38:10 springs to mind.
EM (12:27 AM)
Once again you claim McIntyre is cherrypicking. The point of the particular post in which he displayed 4.3a is to show that the reconstruction in Marcott's thesis did not display the 20th century uptick so prominent in the Science article. Said uptick is not visible in any of those panels you mention. In fact, one of those panels doesn't even contain a Marcott reconstruction (viz., 4.3f). Makes me wonder if you read the McIntyre post, or the thesis.
EM -
Perhaps you should state, to substantiate your claim of cherrypicking, in what way McIntyre's claims of that post are supported by the (shown) figure 4.3a and not supported by the unshown figures.
EM:
That's not very observant of you, EM, since as HaroldW pointed out on 4.2:
and as I pointed out on 4.3:
In other words, your posts have just been a diversion, not a serious attempt at raising anyone's knowledge, and Harold and I have fallen for the trick.
I've also been looking over the Marcott paper. Additional to Steve McIntyre's findings about data selection and re-dating, Marcott also use a resolution trick. Their method is to age-perturb their data 1000x, with each perturbation to be bounded by the age uncertainty of the datum being perturbed. But the earlier data (9000BC-1800AD) has much larger age uncertainty than the recent data -- as a matter of fact, the 1950-dated data have an age uncertainty of zero years. Therefore earlier data is perturbed across hundreds of years, the recent data across a few decades, and the 1950s data -- zero years.
Now (here's the fun part) the output 1000x-perturbed data is binned into 20-year intervals. So up to 1900 all the 20-year bins are liberally cross-pollinated from neighbouring bins, so the result is that the temperature of each bin is quite similar to adjacent bins. But this is not true for the final bin (dated 1940 and covering 1930-1950). This bin's uncertainty is usually zero, so it does not cross-pollinate the adjacent 1920's bin (which covers 1910-1930), and also gets much less from its neighbours than happens elsewhere. Therefore the contrast between 1920 and 1940 is preserved, thus the 0.8C jump from 1920 to 1940 -- but it's just an artifact of the method, because similar temperature jumps across earlier 20-year intervals were wiped clean by the perturbations.
So Marcott achieved their hockey stick by (1) selection, and (2) a trick of resolution. Their data chart shows the perturbed data -- 1000 data points for each individual datum. Faux robust.
I've refrained from making any comment on the recent Marcott et al paper for the simple reason I hadn't read it. I've now had a chance to read it. It is an unremarkable compilation of various palaeoclimate proxies that span the Holocene. Most of these are marine with limited temporal resolution, averaging 120 years, but some with 500 year resolution. Most of the proxy records have limited age control and as a result the age models are poorly constrained. The upshot is, that despite the use of standard and non-standard statistical techniques, the records are necessarily low pass filters that effectively restrict reconstruction to multi-centennialto millenial scale variations in average temperature. The cut off period is on the order of several hundred years. Below this there is considerable attenuation of any signal.
Thus the paper is an unremarkable Holocene record that loses definition on time scales of less than three to five hundred years. As such it would not be considered by Nature or Science for publication. If it's not publishged in Nature or Science then it doesn't impact on the public perception and the climate change debate.
The game is given away in the opening paragraph where the authors discuss the fact that it hasn't yet been demonstrated wether recent warming is anomalous compared to the Holocene record. Unfortunately there is nothing in the properties of the proxy records, nor in the statistical compilation of these that will allow this question to be answered. The uptick in the Marcott et al record is purely an artefact (end effects, manipulation of core end dates thus severely distorting the age models and estimates of sedimentation rate) and contains no information about modern temperatures.
Where we do have high resolution records of climate change (noting that there are problems with many of the transfer functions between the proxy and temperature) that also have excellent dating control we invariably find evidence of rapid and high amplitude fluctuations in the Holocene. One only has to look at some of the speleothem and Greenland ice core records.
I am surprised by the implicit support and promotion this paper has received from scientists who should know better. I call on colleagues to be open and honest about the limitations of some of these proxy studies and to give honest assessments both in professional circles, but also in press briefings and other public domains such as blogs etc. After all it's not rocket science!
Unfortunately, this paper and the way it has been publicly received is symptomatic of virtually every paper and research proposal that comes across my desk these days for review. They all have a variation on the the same opening sentence that seeks to place the work in the context of 'current CO2 induced warming'. A few years ago I even had a paper to review on gas diffusion in butyl rubber that started out with a statement to the effect that given the onset of anthropogenic global warming it was necessary to investigate the diffusion of greenhouse gases through butyl rubber septa that are used in gas sampling systems!
In one sense I see such statements as a form of confirmation bias. This is a very serious issue in modern science that is being driven by government policy, funding organisations etc. If ones views run counter to the prevailing orthodoxy then chances of funding, tenure, career development etc. are all affected. We have to move away from such a stance and try to re-establish the scientific method. Developing hypotheses and experiments or measurements of nature that attempt to refute these hypotheses. We mustn't torture data to fit an apparent paradigm. One can only guess at what Marcott et al were attempting to do when they made gross adjustments to core top dates. It is one thing to run a new, for example 14-C calibration, that will make small adjustments to age models but a completely different issue to redetermine core top dates by such gross margins.
So we are left with a study that is unremarkable in that it shows the broad millenial decrease in global temperatures from the Holocene climatic optimum. It has nothing to say about centennial and decadal variations in temperature, temperature maxima and minima or rates of change, nor does it have anything to say about the modern era. Attempts to picture it any other way are an egregious example of confirmation bias.
Paul: Thank you for distinguishing baby and bathwater so honestly. As I've made clear elsewhere I see the bathwater as containing (small traces of) something worse than confirmation bias. But it's certainly swimming with that. Not good in any way. Scientists, publishers and media all need to issue grovelling retractions, just as a first step.
Nice to have the sanity check from Paul Dennis.
Frankly I think this is now looking like it could be *the* case study to show the pathology inherent in the system.
In future whenever anyone talks of the problems of trust in the "science" - hype, confirmation bias, use of the media , sloppy use of a vast piles of "data" and algorithms to wallow in, - you have it all here.
The coordination of the media hype and high impact journals here - even with "plausible" deniability - is astonishing on its own.
I'd call it implausible deniability in this case TLIB. But yes, this is the case study for later generations. As with Marcott's paper they'll probably get the precise timing wrong but this could well be labelled the moment climate science imploded in hindsight. Those of us without that benefit must fight on.
Paul Dennis -
Thanks for your comment. On the ubiquity of "climate change" references, I have heard a similar story from my brother-in-law about research requests to the US Navy, which needed (somehow!) to be tied to the nuclear reactors on board ships. [Some decades ago; no doubt current requests also cite climate change.]
With regard to the Marcott et al. paper, I agree fully that it does not permit one to speak with any reliability upon rates of change. But the question I have, is whether its assessment of the temperature difference between the Holocene optimum and (say) the Little Ice Age (or some equally modern time) is approximately correct. Because we do have a decent idea of the warming since then (using thermometers, not proxies). What is your opinion?
haha
HaroldW,
your question deserves a more complete answer than I have time to give here. However, in short my answer is no. Apart from the important questions concerning the combination of data of high temporal resolution (modern thermometers) with proxy data that has no ability to resolve anything less than multi-centennial timescales there are other issues. First, without looking more closely at the proxies used by Marcott et al, I suspect they have limited geographic range and possibly don't truly reflect global temperatures. Marcott et al did try to assess the impact of the geographic distributions by looking at different averaging schemes (simple averaging and different weighted area averaging using a range of grid sizes) and report not much variation but more work needs to be done on this.
Second the bulk of the proxies used by Marcott et al are marine. These proxies show very different responses throughout the Holocene. These might be associated with small changes in the position and intensity of ocean currents, evaporation-precipitation fluxes etc. and don't necessarily reflect major changes in mean ocean temperature of a particular area.
Finally I think it is very difficult to compare changes in proxy marine temperatures with changes in air temperature as recorded by thermometers.
Not with standing my criticisms of the Marcott et al paper I do think it is a worthwhile exercise to try and determine temperature and other climatic parameters during different time intervals of the past with as good a temporal resolution as can be obtained. I just wish that workers were honest about the limitations of the science, don't engage in confirmation bias and perhaps above all don't let their advocacy cloud their objectivity and judgement.
Paul Dennis -
Thanks for the prompt and clear reply. Looking at the broad sweep of the reconstruction, the shape is plausible; the smoothness I can attribute to the Monte Carlo approach to chronological calibration, which would tend to smear any jagged bits. I wasn't sure what to make of the peak-to-peak variation, though. As you say, the majority of proxies are marine, and SST varies less than global average temperature.
I find figure S.10 interesting -- it reconstructs temperatures separately in six different latitude zones. The variation of the overall shape of the curves is intriguing, although the latest couple of centuries probably are not indicative of anything but noise.
Thanks Paul Dennis. I was trying to write a summary myself, but you've done a better job.
The following is a post I made at WUWT. I am looking for criticism of the last paragraph.
McIntyre provides a rock solid basis for complaint against Marcott. He writes:
“By blanking out the three most recent values of their proxy #23, the earliest dated value was 10.93 BP (1939.07 AD). As a result, the MD01-2421+KNR02-06 alkenone series was excluded from the 1940 population. I am unable to locate any documented methodology that would lead to the blanking out of the last three values of this dataset. Nor am I presently aware of any rational basis for excluding the three most recent values.
Since this series was strongly negative in the 20th century, its removal (together with the related removal of OCE326-GGC30 and the importation of medieval data) led to the closing uptick.”
The problem described goes way beyond confirmation bias. There is no rational basis for truncating the series. Truncating a series is far more than cherry picking. It is taking deliberate action that changes the series. Because there is no rational reason for the change, the action of truncating the series must be understood as deliberately giving a false impression of the series. Apart from making up data, I cannot imagine a more serious offense by an author.
Thank you, Paul Dennis.
It is very refreshing to read your comments, especially the ones concerning the the way papers are presented these days. I was beginning to despair about the state of climate science.
Climate science: viagra for limp graphs. Get your uptick now!
Revkin's response to Jean S:
//
"From the start, my piece flagged the issues with this kind of analysis and predicted there'd be pushback. A few days ago I added an update to the piece drawing attention to McIntyre's analysis and the Marcott et al. team's plan to issue some kind of FAQ. More to come here when that happens.
As with trends in ocean plankton and warming, reality will emerge, one way or the other."
http://dotearth.blogs.nytimes.com/2013/03/07/scientists-find-an-abrupt-warm-jog-after-a-very-long-cooling/
//
I reread his article as I did not recognise his description of his position. I still don't. Nor do I see how he answers Jean's pertinent on-topic points, yet further up his comment thread he refers to "the whiplash effect" (the point of his link to his plankton article I think) and how he tries very hard not to contribute to it.
IMO Revkin is a complete joke as a journalist: Reality may "emerge one way or the other" but it will continue to struggle DotEarth.
Paul Dennis - are you sending your comments to the editors?
Hey Cassy,
"A more realistic portrayal of my situation would be playing Cassandra to your King Priam. Remember what happened to the Trojans." The former EM.
Wasn't much to choose from between what happened to Cassandra and what happened to Priam. At any rate you have a nice new name.
I posted a link to Paul Dennis' comment at Andy Revkin's DotEarth:
http://dotearth.blogs.nytimes.com/2013/03/07/scientists-find-an-abrupt-warm-jog-after-a-very-long-cooling/?comments#permid=112
theduke - are you sure you have the right link at DotEarth? I followed your link there and it leads back to a blank contributor page here at BH.