UPDATE: McIntyre discovers a serious flaw right away, more upside down Mann world – he writes:
In keeping with the total and complete stubbornness of the paleoclimate community, they use the most famous series of Mann et al 2008: the contaminated Korttajarvi sediments, the problems with which are well known in skeptic blogs and which were reported in a comment at PNAS by Ross and I at the time. The original author, Mia Tiljander, warned against use of the modern portion of this data, as the sediments had been contaminated by modern bridgebuilding and farming. Although the defects of this series as a proxy are well known to readers of “skeptical” blogs, peer reviewers at Nature were obviously untroubled by the inclusion of this proxy in a temperature reconstruction.
More here: http://climateaudit.org/2013/04/11/more-from-the-junior-birdmen/
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‘Charles the Moderator’ writes to inform us that there’s another multiproxy study published, with flat blade and a somewhat limp hockey stick combined with that “unprecedented” claim that has become almost a red flag for bad proxy studies when they are that certain. From the SI PDF file, it looks like it is another splicing study, where they have added CRU data to the paleo reconstruction using tree ring, ice core, and varve data.
I have to wonder though, about the insensitivity of the proxies in the past, that blade seems pretty flat.
Of course it is paywalled, so we can’t examine it in detail yet, but that hasn’t stopped the MSM from ramping up science by press release stories already. The small figure are from the Nature page on the paper.
Abstract:
Recent temperature extremes at high northern latitudes unprecedented in the past 600 years
Martin P. Tingley & Peter Huybers
- Nature 496, 201–205 (11 April 2013) doi:10.1038/nature11969Received 01 September 2012 Accepted 29 January 2013 Published online 10 April 2013
Recently observed extreme temperatures at high northern latitudes1, 2, 3, 4, 5, 6, 7 are rare by definition, making the longer time span afforded by climate proxies important for assessing how the frequency of such extremes may be changing. Previous reconstructions of past temperature variability have demonstrated that recent warmth is anomalous relative to preceding centuries2, 8, 9 or millennia10, but extreme events can be more thoroughly evaluated using a spatially resolved approach that provides an ensemble of possible temperature histories11, 12. Here, using a hierarchical Bayesian analysis13, 14 of instrumental, tree-ring, ice-core and lake-sediment records, we show that the magnitude and frequency of recent warm temperature extremes at high northern latitudes are unprecedented in the past 600 years. The summers of 2005, 2007, 2010 and 2011 were warmer than those of all prior years back to 1400 (probability P > 0.95), in terms of the spatial average. The summer of 2010 was the warmest in the previous 600 years in western Russia (P > 0.99) and probably the warmest in western Greenland and the Canadian Arctic as well (P > 0.90). These and other recent extremes greatly exceed those expected from a stationary climate, but can be understood as resulting from constant space–time variability about an increased mean temperature.
Figure 1: Time series of temperature anomalies and centennial slopes.
a, Average land temperature between 45° N and 85° N (black), 90% pointwise (blue shading) and pathwise (grey) credible intervals20 (see Methods); the unweighted average of all available instrumental observations (magenta)
Figure 2: Warm and cold extremes.
a, The proportion of draws (see Methods) for which 2003 and 2010 were warmest, and for which the warmest year fell in the 1990s and 2000s. White shading indicates zero. b, The fraction of all locations for which years were warmest
Figure 3: Histograms of temperature anomalies and instrumental maxima for the period 1992–2011.
a, Histogram of temperature anomalies across locations, ensemble members and years for the interval 1992–2011 (blue); the simulated distribution of temperature anomalies, using median parameter values fitted over 1400–2011 (black)
===============================================================
There are a number of SI files though:
PDF files
-
- Supplementary Information (8.3 MB)
- This file contains Supplementary Figures 1-53 with legends, Supplementary Tables 1-6, Supplementary Discussion and additional references.
Zip files
-
- Supplementary Data 1 (630 KB)
- This file contains the instrumental data sets used in the analysis, in both original form and standardized as described in the Methods, in Matlab and .txt formats. Also included is a short ReadMe document that describes the data files.
-
- Supplementary Data 2 (716 KB)
- This file contains the tree ring density data sets used in the analysis, in both original form and standardized as described in the Methods, in Matlab and .txt formats. Also included is a short ReadMe document that describes the data files.
-
- Supplementary Data 3 (218 KB)
- This file contains the varve data sets used in the analysis, in both original form and standardized as described in the Methods, in Matlab and .txt formats. Also included is a short ReadMe document that describes the data files.
-
- Supplementary Data 4 (262 KB)
- This file contains the ice core data sets used in the analysis, in both original form and standardized as described in the Methods, in Matlab and .txt formats. Also included is a short ReadMe document that describes the data files.We are unable to host the Supplementary Code and Model output files and these can be found at the following link:- ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tingley2013/tingley2013.zipThese files contain a number of model outputs, available, where possible, in both Matlab and .txt formats. Also included are a number of Matlab scripts that manipulate the model output to reproduce the main features of the analysis, and a short ReadMe document that describes the data and files.
Ok, the key part here is “unprecedented in the past 600 years”. Of course, that is exactly what I would EXPECT to see. What they are saying is that current global temperatures are warmer than they were during the Little Ice Age.
This theory seems to have more splicing, grafting and unnatural manipulation than Frankenstein’s monster.
This is beginning to have that same feel as precursor to an overly used bad joke; stop me if you have heard (read) this one before.
It seems that Mike Mann’s trick is becoming more public knowledge by the day.
crosspatch,
It could also mean that 600 years ago — when CO2 was very low — that temps were higher than they are now.
They can’t even keep their convoluted stories straight.
@dbstealey: I believe there is a reason why they didn’t go father back than 600 years. They did not want to put the post-LIA warming into context with the cooling going into it. If they went back 1200 years, today would not be “unprecedented” at all.
It is sort of like saying that 3pm temperatures reached a level unprecedented over the previous 6 hours. I suspect the finding here would be accurate. What this is doing is intentionally picking start/end points in order to attempt to make things seem worse than they really are. I would fully expect any accurate temperature proxy to show that global average temperatures are warmer today than they were in the 15th century.
“……….expected from a stationary climate.”
Idiots, climate is never stationary. Climate change is the norm, it is the usual state of things and has been for billions of years.
Regarding the bigger picture, what are the chances of this study as well as Marcott et al. being included in AR5? I also note that Muller has circumvented tight peer review scrutiny by publishing work in an obscure journal, Volume 1, Issue 1.
I understand there are deadlines regarding submission of papers to get into AR5, but has the IPCC been pinned down on this, particularly whether they have wiggle room to play loose?
It’s worse than we thought!
The science is settled!
In the UK, snow will be a rare and exciting event!
Climate refugees will move North from the Mediterranean due to drought and encroaching deserts
Vineyards will flourish in Northern England!
The B*****t continues!
Splice at 1880.
So proxies aren’t any good after 1880. Huh.
Without any analysis at all you know this is bolixed up somehow. It is NH, and there is no LIA which is documented not only by proxies but also by observation and early thermometer records. Forget the blade. The shaft is wrong!
This whole branch of historic science, paleo-climatology, has taken on the same persona as alchemy did. Is there a book of secret magic, incantations, codes, and symbols that makes its way around a secret society that has mysteriously endowed the insightful with enlightenment that the rest of us mortals cannot fathom? Maybe, there is a special Hermetic drink that is consumed that opens ones eyes to the proper use of facts and mathematical tweaking while walking the entrails tree rings, ice cores, and lake sediment that brings one to the pre-conceived notion of the truth. It is odd how these self-proclaimed shamans are the only ones who can accurately read these entrails to reveal our past and our future. It has baffled mathematicians as McIntyre, McKitrick, North, Wegman, et al.This secret has found a shape, the hockey stick, the shape of death and almost certain destruction.
The flatness of the blade is generally a signal that the proxies have a lot of noise. I doubt greatly whether most of the proxies themselves look anything like the final graph.
The whole thing looks to my first glance to be a typical product of hockeystick mining … the underlying problem is usually they pick proxies which have a good “fit” with the recent century or so of warming. As a result, the warming is common to all selected proxies to form the blade, and the rest is basically random, to give a nice straight shaft.
At least they’ve included their data, code, and sample outputs. Should make it easy to determine.
And for those who think that the skeptics are having no effect, through unrelenting pressure from the skeptical community, the journals and the authors are starting to actually follow the scientific method, providing the necessary transparency to replicate their results.
w.
For about the gazillionth time…
If they want to overlay proxies with CRU measurements of the same time frame to demonstrate how well proxies work, fine.
If they want to overlay proxies with model outputs to demonstrate how well the models work, fine.
But you freaking well do not splice together two entirely different datasets and pretend they’re the same thing. I recall a mining engineer pointing out that a silver mine investor prospectus that truncated projected silver output and spliced in copper output would get someone sent to jail.
I agree with crosspatch, except that the headline ought to read “Highest temps since the Vikings got frozen out of their farms on Greenland”. We’ve known for quite a while that there are millennium-long climate cycles, and we’re probably pretty close to the peak of the current cycle. (The low solar max numbers posted here a couple of days ago would seem to say that, too.)
Glad to know the LIA lasted till 1920… sarc/
They never learn. Every single time, and I mean EVERY TIME, they come up with an “unprecedented temperature graph” it is shown to be fraudulent. Mike’s nature trick, upside-down Tiljander sediments, redating proxies. Can’t wait to see how their trying to pull the wool over everyone’s eyes here.
I’m going to have trouble with any proxy study using things that can be measured currently without a multi decade, wide area study conducted with well sited, well manged co – located environmental sensors.
Why didn’t someone start doing this in the 1950s?
Do they ever sleep?
good Lord, they smooched all the noise out….
..and now I was born in the LIA
These temperature reconstruction studies are coming at us like sporting clays. PULL!
Another upcoming-UNIPCC-railroad-engineer-political-report-support-paper. This is about “Northern” temperatures, between the most developed area on the planet and the cold Northern wilderness. It is interesting that this is not about “Global Warming” but produces a scarry graph for a scarry headline.
I no longer believe anything these people say. If the UK Met Office, Phil Jones The Poor Bastard, or Mr. Mann told me it was day, I would turn the lights on so I could see.
These people lie, trick the data and are professional propagandists, not scientist.
Anyone remember Lysenko?
I completely understand about temperature estimation. But the hairs on the back of my neck still stand up when anyone says they can tell me what the worldwide temperatures were to less than a degree 200 years before the invention of the thermometer….
Uh oh, they’re switching to a battle of attrition. Quantity instead of quality. When we drop of exhaustion, they’ll have their hockey victory.
Good to see what appears on the face of it be full archiving of code and data.
Maybe Anthony could run a poll so we can guess whether it’s inverted data, selection bias or re-dating again.
Maybe they’ve even invented a new kind of hockey stick.
NZ Willy, you have a point. But there is an answer, which in former times was:
Praise the Lord, and pass the ammunition.
Perhaps some of us can offload Steve M and figure out how the LIA got disappeared.
Have skeptical climate scientists done a study of the Holocene Global Temps? JP
Has anyone with full-text access checked to see if there is an explanation for choosing 1400 as the start date, and whether any of the proxies extend back into the MWP?
TimO says:
April 10, 2013 at 5:23 pm
“I completely understand about temperature estimation. But the hairs on the back of my neck still stand up when anyone says they can tell me what the worldwide temperatures were to less than a degree 200 years before the invention of the thermometer….”
Tim, they don’t tell you what the temperatures were. They tell you what the proxies they’ve chosen suggest the temperatures were within the constraints of the methodology they’re using, and the statistical likelihood of error. That’s why Willis and others have rightly pointed to the importance of providing the data, code and sample outputs. JP
This is like playing “wack-a-mole;” as soon as one hockey stick study is wacked, a new one pops up!
crosspatch said @ April 10, 2013 at 3:41 pm
Thanks Crosspatch! That comment made my day :-))))))))
Do you think Steve is going to wait 2 weeks to blow this one out of the water?
‘Unprecedented’ should be banned from the literature.
The amount of coffee I have had in the last hour since arriving at work is unprecedented since I woke up this morning, in fact since last night when I was also asleep. zzzzz.
It’s the Mann method! First flatten out any change in the past, and the graft on the unjustified, manipulated temp record Hansen produced. BOOM! You get published for the first time in years.
Now if they can just find a way to get rid of all that frozen and snow across the USA Midwest, the UK, Germany, Russia, ….
They have made a rather horrid fault of “doubling down” right when the Average Joe is saying “What the… I’m freezing here!”
Just put their Hokey Stick up next to the reports of “Coldest in 100 years” and ask The Folks which one is frosting their shorts…
Is that graph showing a +1.0C rise since the mid-70s?
Not even GISS suggests that.
Willis Eschenbach says:
April 10, 2013 at 4:07 pm
“…And for those who think that the skeptics are having no effect, through unrelenting pressure from the skeptical community, the journals and the authors are starting to actually follow the scientific method, providing the necessary transparency to replicate their results.”
*
Thanks, Willis. Sometimes I really wonder, you know? Your words are soothing to me and I appreciate them. You’re right, of course. The MSM is waking up, too, and beginning to ask tough questions. It’s all good – it’s just that sometimes it seems to take so long. I know, it’s a big beast and it’ll take some time yet. I have to keep reminding myself it’s happening. Statements like yours help me realize, yes it is. Thank you.
It looks more like a graph of Northern Hemisphere UHI in major cities than anything else. This is yet another job for Climate Audit and Steve McIntyre’s bogus statistical detector.
CET record and NH extratropics record do match very well for 1850-present period, so CET is a valid proxy for NH back to 1659. In CET, there is abrupt warming between 1690-1740, being twice the modern warming and reaching almost present levels. It is nowhere to be seen in this hockey stuff. Wake me up when some realistic proxy record will be available.
Mulligatawny Proxies
Mulligatawny soup is made from a number of ingredients of differing color and taste that when combined give a uniform color and taste. These latter attributes can be altered by selecting the ingredients and their proportions or adding cream etc to the finished product.
Like the ingredients in Mulligatawny soup, climate is not global or regional but zonal and sub-zonal – that is why we can describe the end result in terms of the Köppen–Geiger climate classification system that reflect temperature, precipitation, altitude, latitude and surface effects. For temperature and precipitation it is not just local effects that count but more distant ones via teleconnections.
The available ice core, tree and varve proxies only reflect the climate in the zone or sub-zone where they are situated and can only reasonably be compared with the recent temperature data for that zone (the added cream) – global values are like making Mulligatawny soup from them to give the “desired taste” but have little meaning. They only confuse the situation, as well as the IPCC and those alarmist climate scientists that produce them in believing they reflect some global effect of increased atmospheric carbon dioxide – whereas the effects of CO2 are also zonal and sub-zonal via its effect on vegetation as the satellite data shows.
The boundaries of the climate zones and sub-zones change over time with variation in solar activity and the inclination of the Earth’s axis. For example the switch 5000 years ago of the Sahara and areas of the Middle East to desert zones and the movement south of the northern tree line. Thus, over a time span of the thousands of years used in these proxy studies the results at the boundaries represent a mix of temperature and precipitation changes of several zones and cannot be compared with current temperatures. Yet many of the proxy studies do sample the boundaries.
http://oi47.tinypic.com/290yfx2.jpg
The above chart with scaled 45-85 NH CRUTEM and CET data. The last blade seems identical both with NH instrumental record and CET as well, but the previous period is much flatter than CET, missing warming and cooling periods comparable or more pronounced than the recent one.
See CLIMATE AUDIT
I too am extremely sceptical of proxies because of the difficulty of extracting the desired signal (the response to temperature changes) from the noise (the general response to favourable environmental conditions in general which temperature is but one factor and often not the dominate factor).
There are further problems with resolution, response, calibration and tuning. All of these give huge error bars which do not appear to be acknowledged.
As a consequence I consider that proxy studies are nearly worthless, especially if on is seeking to draw a comparison with todays temperatures obtained from the high resolution thermometer record (which is not a like for like comparison).
Today’s warming appears mainly routed in the Northern Hemisphere and milder winter temperatures, especially night time temperatures. It may well be the case that old proxies fail to detect such changes if those changes had occurred in similar fashion in the past and hence one reason why the stick may be rather flat. These changes are being detected by high resolution thermometers but may not lead to a change in growth patterns of old proxies and hence not be detected when the old proxy data is reviewed.
There is some debate as to whether the MWP was global or not. However, it is quite possible that it was more dominant in the Northern Hemispher than in the Southern Hemisphere just like the warming is today. Possibly because of southern ocean damping and the larger land mass in the north.
Wasn’t it Michael Mann who said that no serious scientist had ever attached thermometers data into a reconstruction by proxies?
A.D. Everard says: April 11, 2013 at 12:03 am
“…Thanks, Willis. …You’re right, of course. The MSM is waking up, too, and beginning to ask tough questions….”
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This is because of the present financial crisis and rising energy costs. The journalists are beginning to appreciate that high energy costs is causing fuel poverty for the consumer and creating all kinds of difficulties for industry. Industry in developed nations is struggling to compete with that of developing nations partly because of high energy costs.
MSM has appreciated that shale gas has revitalised the US, and whilst its economic recovery is sluggish, such recovery as there has been is largely powered on the back of shale. Europe is beginning to appreciate that it cannot compete with the US (let alone with developing nations) because of the divergence in energy costs. In the US the gas spot price is 4 to 5 times lower than in Europe. The realisation is beginning to dawn that Europe will not be able to recover if shackled by high energy costs. Europe does not have a workable energy policy, only a green policy!
Coupled to all of this has been the recent spate of bad winters (the CET winter temperatures have fallen by a staggering 1.5degC this century). Global warming may have stalled, but winter temperatures in Europe is dropping and dropping fast. This is causing all sorts of problems. Placing a strain on an over strained power generating system which has been closing many reliable coal powered stations and being too reliant on unrelaible and costly green energy which people and business alike cannot afford. It has also played havoc with farming. In the UK (particlarly Scotland and Wales) live stock farmers are really struggling with many live stock deaths. This will put up the price of food (bad for the consumer) even if it does not force the farmer out of business (even worse for the consumer).
The newspapers are full of these largely economic stories but on the back of these stories is the ever growing realisation that the world is no longer warming, so what has happened to global warming?
Incidently, the difficulties that farmers have recently encountered with harsh winter conditions just illustrates how much warmer the MWP must have been than today for the Viking farmers and setllers to have settled in Greenland for several hundred years. There is no way they could have survived in Greenland for so long, had farming just been on the cusp of survival. It must have been a time of plenty to have enabled them to come through the odd one or two bad winters which must have inevitably occurred. I consider that the temperatures in high northern latitutes must have been very considerably warmer than today for the Vikings to have survived so long. It would appear that these more benign conditions were not limited to in and around Greenland in view of the evidence of Viking transatlantic crossings.
Some of the terms used in this paper are cause for concern.
“These and their recent extremes greatly exceed those expected from a stationary climate, but can be understood as resulting from constant space-time variability about an increased mean temperature.”
This paragraph in particular could not have been written by a scientist without the aid of lsd, or a propagandist.
This suggests that all over the world every day for many hundreds of years has been a pleasant 14.7C and a 1013 mb and only recently we have suffered weather.
It would also seem that CO2 can alter the space-time constant or is it continuum and cause the temperate on Earth to rise.
I would like to know where these people were educated so I can avoid the place.
A scarry graph for a scarry headline, that is its objectives not furthering science and like many BS claims before it the job is sadly done . The IPCC will lap it up has ‘proof ‘ without spending 1 second checking the facts and gravy train rolls on .
Stephen Richards says:…See CLIMATE AUDIT http://climateaudit.org/2013/04/11/more-from-the-junior-birdmen/
Chuck L says:
April 10, 2013 at 7:30 pm
One for Josh there: the ‘whack-a-mole hockey sticks’!
Someone please tell me again: Why is it that we cannot have proxy records right up to the present day? I recall that there is some reason why we cannot rely on them in the present. But if valid proxy records to the present do exist, and if they fail to show an increase, isn’t that the real story?
Proxy-til-they-drop, is all they’ve got left in the tank. It’s what worked before in the glory days. And man, can they ever turn this stuff out!! Too bad the AR5 draft was leaked so soon – it put these guys in overdrive – they were given a deadline and marching orders. Surely it’s “unprecedented” that one proxy after another, all of which say the same thing, is so readily published in such a short time. A proxy derby. Can Steve McIntyre keep up?
dabbio:
You raise the interesting issue of splicing when you ask at April 11, 2013 at 3:33 am
Few proxies indicate the temperature of individual years: they indicate the average of temperatures over several years.
For example, consider growth of tree rings in a tree as a proxy for temperature. There are many reasons why the growth may vary; e.g. the tree’s bark eaten by deer, the tree’s nutrients increased by death of an animal burrowing near its roots, bears doing what they are said to do in woods near or not near to the tree, etc. It is assumed that over several years (e.g. 100 years) all these factors cancel out to leave the growth indicating temperature. But that means the temperature is an average of the sampled time (e.g. 100 years).
Hence, proxies are said to have low temporal resolution (in the example, the tree only resolves temperature averaged over 100 years).
The temperature measurements have higher temporal resolution: they measure average temperature over single years.
This has several effects and two important effects are
(a) lack of recent proxy data
and
(b) inability to directly compare the proxy data to the temperature measurements.
If the average time indicated by a proxy is 100 years then the most recent indication is for temperature centered on 50 years ago: there is no data for more recently than that.
And the datum from the exampled proxy for temperature 50 years ago is not the same thing as the temperature measured 50 years ago. Global temperature rose ~0.8 deg.C over the twentieth century and the temperature measurements show this. But a proxy averaging over 100-year periods would provide the average rise over that century which was ~0.4 deg.C. Clearly, splicing the proxy indications onto the temperature measurements is very misleading.
The degree that such splicing misleads increases as the temporal resolution of the proxy reduces.
I hope this is a sufficiently clear and adequate answer.
Richard
dabbio says: April 11, 2013 at 3:33 am
“Someone please tell me again: Why is it that we cannot have proxy records right up to the present day? I recall that there is some reason why we cannot rely on them in the present. But if valid proxy records to the present do exist, and if they fail to show an increase, isn’t that the real story?”
Proxy records do not have short term resolution of temperature estimates, only long term….
richardscourtney says: April 11, 2013 at 4:01 am
Sorry Richard, I was a bit slow….
The 2nd graph shows about +/-0.4 deg C accuracy 400 years ago. Impressive ! It’s better than today’s instrumental record.
If there are upticks in last century or so and proxy records have low temporal resolution necause they need time to “settle down”, perhaps we are simply observing the process of the proxies settling down?
Ben D:
re your comment to me at April 11, 2013 at 4:10 am.
Please do NOT apologise.
I am grateful for your answering the question from dabbio, and dabbio may be more grateful for your answer than for mine.
Different people grasp information in different ways so a variety of answers is always good. One answer to a question having appeared is not a reason for a variety of other answers to a question also being posted whether or not they say the same thing.
There is a lesson for us all in this. We each have things to share with each other so we can learn from each other, and I think our individual ways of sharing are all important.
Richard
richardscourtney says: April 11, 2013 at 4:38 am
You are kind Richard, and might I say, it’s a delight to read your comments here on WUWT…
Richard and Ben, your efforts to educate me are highly appreciated.
I sure hope they un- firewall the paper soon, ’cause i need some help understanding the disrupted climate. We awoke to an ice storm in central Oklahoma yesterday and the trees remained encased in crystal until late afternoon. This is a rare event for central Oklahoma. My Dad’s in his 80’s and he’s never seen ice this late either, although the big pond on his ranch is finally starting to get close to filled after the drought we’ve had for several years, which does happen all the time, but is now our fault, due to Global Warming, or so they say.
There is some way to attribute this to Global Climate Disruption, but I can’t remember how it goes, let’s see… warmer air holds more moisture, so that could account for the water to make the ice, but with April showers, maybe not, and then how could it be warmer air, if it’s cold enough to freeze?
My neighbor is all aggravated, because the USDA has revised the local planting dates to match the Global Warmer predictions, but they haven’t yet revised the dates back to account for Climate Disruption, and that is bad for tomatoes.
Maybe some rich and famous “climate personality” will stop by and tell me how it all works,
Looks like I was right….
“Average land temperature between 45° N and 85° N”
—————————————————–
I thought we were looking for global warming not regional.
My guess is they’ll guess for the rest of the global.
cn
FYI, Tingley and Shakun (of Marcott et al.) are both currently junior researchers in the Huybers group at Harvard:
http://www.people.fas.harvard.edu/~phuybers/
Huybers commented on some Mann issues in 2005, although did not seem to work through the criticisms fully.
Huybers could become “part of the solution” in paleo climate issues, unless he continues to be “part of the problem” as the 1960s-speak used to say….
Just an aside, Huybers in 2005 in response to McIntyre and McKitrick:
http://www.people.fas.harvard.edu/~phuybers/Doc/hockey_grl2005.pdf
http://www.people.fas.harvard.edu/~phuybers/Hockey/
Another proxy study where the ‘r’ is silent.
To those are making accusations of ‘trickery’ or ‘manipulation’, you should know that Huybers is a West Point grad and former tank platoon leader during Bosnia. He is a man of integrity (see his inclusion of data and code) and deserves a little more respect.