Gavin Schmidt, Michael Mann, and Scott Rutherford have written a comment letter to the Annals of Applied Statistics to the Hockey Stick busting McShane and Wyner paper covered on WUWT in August.
It’s quite something. Here’s the M&W graph:
It only took reading the first paragraph of the Team paper for me to get cheesed off. Emphasis mine:
McShane and Wyner (2010) (henceforth “MW”) analyze a dataset of “proxy”climate records previously used by Mann et al (2008) (henceforth “M08”) to attempt to assess their utility in reconstructing past temperatures. MW introduce new methods in their analysis, which is welcome. However, the absence of both proper data quality control and appropriate “pseudoproxy” tests to assess the performance of their methods invalidate their main conclusions.
Why am I cheesed off?
The sheer arrogance of claiming improper “data quality control” when Mann himself has issues with his own papers such as incorrect lat/lon values of proxy samples, upside down Tiljander sediment proxies, and truncated/switched data, is mind boggling. It’s doubly mind boggling when these errors are well known to thousands of people, and Mann has done nothing to correct them but then speaks of data quality control issues in rebuttal. And yet Schmidt defends these sort of things on RC. It’s like the Team never read the McShane Wyner paper, because they clearly said this about data issues:
We are not interested at this stage in engaging the issues of data quality. To wit, henceforth and for the remainder of the paper, we work entirely with the data from Mann et al. (2008)
So MW used Mann’s own data, made it clear that their paper was about methodology with data, and not the data itself, and now the Team is complaining about data quality control?
The Team egos involved must be so large that the highway department has to put out orange road cones ahead of these guys when they travel. And they wonder why people make cartoons about them:
They go on to whine about the MWP being “inflated”.
MW’s inclusion of the additional poor quality proxies has a material affect on the reconstructions, inflating the level of peak apparent Medieval warmth, particularly in their featured “OLS PC10”
Well, here’s the thing gents; you don’t KNOW what the temperature was during the MWP. There are no absolute measurements of it, only reconstructions from proxy, and the Team opinion on what the temperature may have been is based on assumptions, not actual measurement. You can’t set yourself up as an authority on knowing whether it was inflated or not without knowing what the temperature actually was. They also rail about “poor quality proxies” (their own) used in MW. Like these?
Half the Hockey Stick graphs depend on bristlecone pine temperature proxies, whose worthlessness has already been exposed. They were kept because the other HS graphs, which depend on Briffa’s Yamal larch treering series, could not be disproved. We now find that Briffa calibrated centuries of temperature records on the strength of 12 trees and one rogue outlier in particular. Such a small sample is scandalous; the non-release of this information for 9 years is scandalous; the use of this undisclosed data as crucial evidence for several more official HS graphs is scandalous. And not properly comparing treering evidence with local thermometers is the mother of all scandals.
Read the entire Team response here, comments welcome.
http://pubs.giss.nasa.gov/docs/notyet/inpress_Schmidt_etal_2.pdf
Backup location in case it falls down a rabbit hole: inpress_Schmidt_etal_2
For balance, the McShane and Wyner paper is available here: http://wattsupwiththat.files.wordpress.com/2010/08/mcshane-and-wyner-2010.pdf ======================
h/t to poptech
======================
UPDATE: Here are some other views:
Jeff Id, The Air Vent:
http://noconsensus.wordpress.com/2010/09/23/ostriches/
Luboš Motl, The Reference Frame:
http://motls.blogspot.com/2010/09/schmidt-mann-rutherford-just-clueless.html
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Are the words affect and effect used differently in statistics compared to common usage?
Please, someone answer me. Did I read this right? They are complaining about the quality control of the data, and the data is Mann’s? And this is their rebuttal?
This reminds me of the saying I was taught in accounting. “Figures don’t lie, but liars Figure.” Be wary, science is using this accounting practice.
“Which brings me to an off-topic discussion. The following post at RealClimate on the effects of Downward Longwave Radiation on the oceans always stuck me as odd, but I can’t put my finger on why:”
Off topic. But briefly: they seem to be saying that when it’s cloudy, more heat stays in the ocean, warming it up. That sunny weather (driving a stronger surface-to-air heat flow?) is correlated to a larger temperature gradient. That even the difference between bright sunlight and thick cloud is barely detectable, let alone that between 280 ppm vs 380 ppm. And it’s confirming the consequent – there may be many other reasons why sunny/cloudy weather could change the skin layer temperature gradient, besides LW radiation balance. Those were my initial impressions.
The Mann, Schmidt, and Rutherford comment letter
(hereinafter referred to as MS&Rlet2010) concerning
elements of the McShane and Wyner 2010 paper for the
Annals of Applied Statistics (hereinafter referred
to as the M&W2010 paper ) is a marvel of fallacious
arguments and circular logic.
Fallacious set up and arguments:
MR&Slet2010 faults M&W2010 for
having included the 36 proxy data sets Mann et alia 2008
(hereinafter referred to as Mann, et al. 08 )
arbitrarily threw out because they somehow didn’t
agree with the Team’s self-imposed “standards of
objectivity”.
However, Mann et al 08 kept both the soon-to-be
controversial Briffa and Tiljander proxy data sets in
play and used them along with the other specific data
sets that comported to their arbitrary “objective
standards”.
The peer review process for the Mann et al. 08
paper, and the non-peer reviewed Supplemental
Information to Mann el al. 08 08 ) never fully
explained why the 36 data sets they tossed were
wholly unusable. The Supplemental Information entry
was a late creation aiming to satisfy in part and silence
in whole the non-Team critics (and their readers) of
Mann et al. 08.
They now fret that the M&W2010 inclusion of
what the Team had previously and publicly labeled
“poor quality proxies “ have “a material effect” on the
several different statistical methods and the consequent
temperature reconstructions“. They ignore the other
half of their own syllogism mandating that dropping these
proxies also has had a material effect on the Mann et
al. 08 calculations as well as a few previous and all
subsequent reconstructions based on the Mann et al
08 data sets. IPCC 2007 is included in the users and
interpreters of the data sets.
.
MR&Slet 2010 argues and complains that
M&W2010 uses these tossed data sets to “inflate”
the reconstructed temperatures of the Medieval Warm
Period. The Team finds that an unacceptable practice.
However, tossing out these same data sets results in the
deflation of the temperature reconstruction calculations for
the Medieval Warm Period. The team and subsequent users
of the Mann et al 08 data sets see this as a
perfectly acceptable practice.
Circular argument(s):
MR&Slet 2010 cites Salzer et al 2009, and
Jansen et al 2007, as well as IPCC 2007 as props
for their arguments. (The “et al” in Jansen 2009
includes Ken Briffa as a coauthor.) However, none of
these studies fully described or used the 36 tossed
data sets available to but not used in Mann et all
2008. These tossed data sets are discussed in the
MS&Rlet2010, but never actually used to
refute the temperature reconstruction calculations
of M&W2010. .
The various studies following Mann98, IPCC 2007,
Jansen 2007, and Mann el al. 08 and now
MS&Rlet2010 will obviously agree in term
of the signal strained from the statistical soup Mann,
et alia, have stirred, stewed, and plated with his
non-traditional statistical methodologies and arguments.
Personal comment:
The Mann, Schmidt and Rutherford 2010 letter to
the Annals of Applied Statistics seems a
fine example of what the Team tries to do when
peer reviewed material appears… but not written
under the aegis of the Teams’ circle of peer review
friends and co-authors.
How fortunate for the Team the Annals of Applied
Statistics doesn’t require peer reviews of the
“comment” letters that are submitted.
The Mann, Schmidt and Rutherford letter is a free
ticket to the 2010 Logic Chopper’s Ball !
It has been pointed out by those far more eloquent than myself, but it bears repeating, and often:
The study was about the method, not the data. It appears that the Hockey Team have either misunderstood or are being deliberately misleading, by concentrating on the data.
Anthony,
Your title: RC’s response to McShane and Wyner: a case of orange cones
New & improved title: RC’s response to McShane and Wyner: a case of cone heads
: )
John
Bob Tisdale says:
September 23, 2010 at 2:55 pm
I’m not a phsyicoclimatologicomathamagician and I didn’t read the whole article but at first scan this quote from the fourth paragraph caught my attention:
“If we can establish a relationship between the temperature difference across the skin layer and the net infrared forcing, then we will have demonstrated the mechanisms for greenhouse gas heating the upper ocean.”
They seem to have demonstrated that there is more IR forcing when clouds are present than when they are not (water vapor is a GHG too), and skipped to the conclusion that it supports CAGW…er…CC…er…CGD…er, whatever.
Oops, need spellcheck: physicoclimatologicomathemagician(c) 🙂
This comment, SMR, was mainly about the method — which if you look at the graphs which benchmark the method against synthetic proxy* data (which is different from the pseudoproxy data generated in MW) you see that the MW methods consistently overestimate MWP warmth when they are run against a dataset where the answer is known (this is the whole point of synthetic proxies).
Even more damning is Fig. 2 in Tingley’s comment, which shows that the LASSO method can calibrate AR(1) random pseudoproxies to an linear trend + AR(1) noise. Since the MW conclusions about the uselessness of proxy data seem to be based on the results of LASSO, this calls into question the conclusions of this portion of the paper. The performance of the OLS PC10 reconstruction offered by MW is shown by SMR to suffer from (as stated in the SMR comment) over fitting. Using the more appropriate 4 PCs (OLS PC4) gives more realistic results, but not as good as Mann’s EIV Hybrid method. This is why performance of the synthetic proxies fed into a new method is important and has become standard practice in the paleo community. If a method gives poor results in this context, it is unlikely to give good results when fed real data with the same noise characteristics.
* For those of you who may not know, synthetic proxies are proxies taken from the same grid squares of a climate model run as the real dataset and polluted with white noise of approximately the same character as the noise found in the real proxies. In this case the SNR is about .125 or 8 parts noise to 1 part signal. These synthetic proxies are then fed into the reconstruction method to see whether or not it produces a result similar to the known result (the output of the climate model). SMR shows that both of the methods used by MW fail miserably in comparison to the actual methods used by M08. RTFC and look at the figures and the figures in the SI, which are linked in the comment.
No.
M&W used proxy data rejected by Mann 08 for being unreliable. This was always going to be an issue when, as M&W stated, they were not concerned with the quality of the data. They would put their statistical expertise to better use in collaboration with paleoclimatoligists. As people on both sides have said, neither group benefits from working in isolation.
anna v says: (September 23, 2010 at 6:22 am) I will take the risk of sounding elitist
You do not sound elitist, Anna, but entirely, and sadly, realistic.
barry,
With all due respect, that self-serving Michael Mann quote is a steaming pile of horse manure. A “frozen” MWP? Please. Mann is so transparent. He’s still trying to sell a flat handle on his debunked and broken hokey stick.
And: “MW’s inclusion of the additional poor quality proxies has a material affect [sic] on the reconstructions…” Doesn’t this jamoke have a proof reader??
Regarding ‘poor quality’ proxies, read Montford’s The Hockey Stick Illusion. Then report back, and we can have an interesting discussion about who is guilty of using poor proxies.
Smokey,
No. They’re talking about the proxy data, not temps. Mann and others have always maintained that the medieval period was warm.
It would be a simple matter to check and see from Mann 08 whether they did what they said with the 95 proxy data sets. If you are able to go further and determine whether or not their treatment was sounder than M&W, then you’re a much cleverer person than I.
“These are not the droids you’re looking for” has become known as the Jedi Mind Trick. Goes nicely with Mike’s Nature Trick, eh?
It was Baghdad Bob, also known as Mohammed Saeed al-Sahaf, the Iraqi Minister of Information who said: “They are not near Baghdad. Don’t believe them…. They said they entered with… tanks in the middle of the capital. They claim that they – I tell you, I… that this speech is too far from the reality. It is a part of this sickness of their plan. There is no an… – no any existence to the American troops or for the troops in Baghdad at all.” As American troops were celebrating the capture of Saddam Hussein’s parade grounds, just around the corner, Baghdad Bob says, “There you can see, there is nothing going on.”
Do we now have a new candidate ClimateGate Owen vying for the title of ClimateGate Minister of Information?
The CAGW crowd are getting desperate and throwing out anything and everything to delay the inevitable. They need an out, something that will let them save face, if we can’t provide them that we’re all in for bloody trouble. All we need is to get some reasonable evidence out there that they can agree with, but also could be interpreted another way (which they did for some unknown reason).
In a few weeks you guys are all going to be wishing you had been a lot nicer to old Mikey.
http://news.yahoo.com/s/prweb/20100914/bs_prweb/prweb4491804_1
“A newly-published book by a retired NORAD officer predicts October 13, 2010 as the tentative date for a fleet of extraterrestrial vehicles to hover for hours over the earth’s principal cities. Author says the event to be the first in a series intended to avert a planetary catastrophe resulting from increasing levels of carbon-dioxide in the earth’s atmosphere dangerously approaching a “critical mass.””
However, this does highlight the severe difficulties the AGW crowd has had with PR. If, instead of all that hogwash about consensus science, they had just come out and told us they had ET on their side, we could have avoided all this unnecessary bickering.
There is a bit of silver lining in this black cloud, because Cap & Tax is evidently not going to be required
“The book, Challenges of Change (3rd ed.), reports this event will be the initial interaction in a process leading to mankind’s acceptance of the alien reality and technologies for the removal of poisonous gases from the earth’s atmosphere in 2015, if not sooner.”
This is all such great news that I think I’ll just go and have myself a few celebratory beverages.
Barry @ur momisugly 9:47 pm: “Mann and others have always maintained that the medieval period was warm.”
This is completely false. Mann’s MBH99 Hockey Stick “paper” had NO MWP ( and no LIA – it is reproduced on the back cover of “The Hockey Stick Illusion”). Numerous other ‘reconstructions’ by “The Team” also claim no MWP.
Totally in line with the email Team member Jonathan Overpeck sent to David Deming, “We have to get rid of the Medieval Warm Period” (ref: “The Hockey Stick Illusion”, p28).
Bob Tisdale says:
September 23, 2010 at 2:55 pm
Which brings me to an off-topic discussion. The following post at RealClimate on the effects of Downward Longwave Radiation on the oceans always stuck me as odd, but I can’t put my finger on why:
http://www.realclimate.org/index.php/archives/2006/09/why-greenhouse-gases-heat-the-ocean/
Answer to off topic:
Without spending too much time on the post you quote, I think they are talking of temperature differences between the skin surface of the ocean, the one that enters the stephan boltzman equation, and 5cms below. Note: differences, not absolute temperatures.
I distrust this as I distrust anomalies, because differences introduce enormous distortions.
Using the cloud shadow might sound ingenious, but since I find nowhere the word
evaporation, except in the comments, I think the experiment is not controlled at all. Direct sunshine evaporates a lot more than shadow, which means cooling, which means extra dimensions in the difference between surface and 5cms that have not been addressed. Convection between 5cms and skin is not addressed. ( They do not say that the experiment was done at night) What they are showing/measuring is a projection in two picked dimensions from a much more complex unstudied/not-described system.
It would be interesting to see the temperatures and not the differences.
And not to forget that 5cm is not bulk ocean temperature, the reservoir of ocean heat is at much greater depths.
my two cents on this.
When I try to envision these three–Gavin Schmidt, Michael Mann, and Scott Rutherford– in the private sector I get the tobacco industry of the 60’s and substandard oil and coal and wind power companies with serious liquidity problems.
Totally in line with the email Team member Jonathan Overpeck sent to David Deming, “We have to get rid of the Medieval Warm Period” (ref: “The Hockey Stick Illusion”, p28).
This quote has the status of hearsay, strongly contested by the alleged quotee. Deming no longer has the mail that he alleges contained that text, and Overpeck said, in a ‘Climategate’ mail…
“> > I have no memory of emailing w/ him, nor any
> > record of doing so (I need to do an exhaustive
> > search I guess), nor any memory of him period. I
> > assume it is possible that I emailed w/ him long
> > ago, and that he’s taking the quote out of
> > context, since know I would never have said what
> > he’s saying I would have, at least in the context
> > he is implying
Montford is aware of this of course, but while the quote is foregrounded on p28, readers must read on another 400 pages to discover that the alleged author never used the words in the sense in which they are meant. A serious historian would not use such material, or else would caveat it heavily. But it’s just TOO useful to the narrative that Montford wants to spin, so in it goes…..
More like the State Pen(itentiary). No one there has ever done anything wrong.
Such an offer has been made, repeatedly, and refused or ignored, repeatedly. Clearly Mann is not interested in statistical integrity. I think he knows he’s produced junk, but like Clinton, hopes that if he keeps denying it vehemently then people will believe him.
What context would he like to apply to that quote?