More on the Marcott et al “hockey stick”. All of the ‘Marcott 9’ had altered dates.
![marcott-A-1000[1]](http://wattsupwiththat.files.wordpress.com/2013/03/marcott-a-10001.jpg?quality=83)
While it took me a while to get the time together to write an article about the Marcott paper, that does not mean I have not been looking at it and discussing it from nearly the day it was released. There has been volumes of discussion within The Right Climate Stuff group that I have been involved with. The ones that lean towards CO2 as something to be concerned about were initially rather excited about this paper, but that has taken a course correction as it has become clear how poor the science is in the Marcott paper.
Many skeptics are calling this the newest hockey stick and there is certainly some accuracy to that, but what I initially found interesting was the Holocene cooling that he shows. In one respect his paper is different because it shows the cooling that has been taking place for thousands of years. That also makes the stick at the end more extreme, but it is something most will not show.
For those who missed the details of the Marcott paper I will provide a brief summary. The paper was published on March 8th in the ultimate of peer-reviewed journals, Science Magazine. The paper was loudly broadcast by the media as further proof of global warming. The paper basically says that the most modern period of the Holocene (the current interglacial which the Marcott paper states as 11,300 years) has been warmer than ~75% of the Holocene. The paper states that this is especially significant as the Holocene has shown steady cooling for the past few thousand years, but that has now completely reversed. The conclusion is that mankind has drastically altered the natural climate of the Earth.
The paper itself is a composite of 73 different temperature proxies. These proxies were used to reconstruct the Earth’s climate over the past 11,300 years. The 73 proxies were not uniformly distributed around the world. The following is a summary of the spatial distribution.
Tropics: 33 proxies
NH Polar: 12 proxies
NH Mid: 20 proxies
NH Tropics: 16 proxies
SH Polar: 4 proxies
SH Mid: 9 proxies
SH Tropics: 12 proxies
NH Total: 48 proxies
SH Total: 25 proxies
The NH is over represented by 3x in the polar region and 2x in the mid-latitudes. This of course can be dealt with easily enough, but the real resolution in the NH is better than the SH. None of this is directly critical to the paper, but it is something worth noting.
Far more troublesome to the conclusion of the paper is the dating of the proxies. Other sites have some excellent write-ups on the re-dating in the paper itself and I will touch on it, but my more immediate concern is how recent most of the proxies are based on the published data of the proxies.
Here is the breakdown of the last date in the proxies he used.
1950+ 9 proxies (1960, 1970, 1991, 3x 1995, 1998, 1999, 2000)
1900-1950: 16 proxies
1800-1899: 11 proxies
1600-1799: 7 proxies
1000-1599: 14 proxies
< 1000: 15 proxies
This leaves one proxy (GeoB 3313-1) with the last known data of ~1750 AD. There are 3 data points for temp after that, but no dates associated.
Since the modern period by almost everyone is considered to be post 1950, only 9 of the 73 proxies contain any data that can be relevant to the global warming issue. Right away that concerned me, but when I looked at the data for those 9 proxies something very interesting became apparent.
I will be referring to those 9 proxies as the Marcott 9. They are perhaps the most interesting proxies that he used and those proxies disprove the conclusion of his paper. In order of the most modern data, the Marcott 9 are:
Lake 850, most recent data is from 2000.
Flarken Lake, most recent data is from 1999.
Lake Nujulla, most recent data is from 1998.
Tsuolbmajavri Lake, most recent data is from 1995.
Homestead Scarp, most recent data is from 1995
Mount Honey, most recent data is from 1995
Composite MD01-2421…, most recent data is from 1991
Moose Lake, most recent data is from 1970
Agassiz & Renland, most recent data is from 1960
What is most interesting about all of these proxies is that none of them show the warming result the paper ended up with. Not a single one.
Without further ado, here are charts for the Marcott 9.
These nine proxies are the only ones of the 73 that Marcott used that have data past 1950. The only one that shows any kind of warming is the last one which is the Agassiz-Renland ice core and the warm point was not the most recent, but the proxy from 1940. The last point which is 1960 shows as cooler than the data from 1940. The ice core certainly does indicate that the warming in the 1930-1940 period was impressive, but few claim that mankind caused that warming.
There is far more to discuss about this paper. I have an idea where I am going to go with my research, but others may beat me to it which will alter the path I take. Based on what information is being found by others, primarily by Steve McIntyre over at Climate Audit is that Marcott re-dated data that didn’t fit into the hockey-stick result.
This agrees with what I have found as well. All of the Marcott 9 had altered dates associated with the last date with the Moose Lake data changing the least at 20 years. Flarken and Tsuolbmajarvi Lake were moved back into the 1800’s and the MD01 Composite removed the last 3 data points. The end-point strategy for this paper was full of shenanigans. Since it is only the end-point data that matters to the conclusion of the paper, well, let the Marcott 9 speak for themselves.
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John Kehr is a Chemical Engineer by schooling and Research and Development Process Engineer by profession. He has more than a decade of experience at the cutting edge of technology for a large semiconductor company. That experience was critical for him while wading through the often contradictory information that exists about global warming. He was generally neutral about the subject of global warming until he met and married a wonderful woman who challenged him to make a choice.
There are few things more dangerous than challenging an engineer to make a choice like that on a scientific topic. While occasionally taking a break from research to breathe and go on getaways with his beautiful wife, he spent many months deeply involved in his research. When he finally reached his conclusion, the only logical thing was to put all that research into a book, The Inconvenient Skeptic
Related articles
- McIntyre finds the Marcott ‘trick’ – How long before Science has to retract Marcott et al? (wattsupwiththat.com)
- How Marcottian Upticks Arise (climateaudit.org)
- Hiding the Decline: MD01-2421 (climateaudit.org)
- The Marcott-Shakun Dating Service (climateaudit.org)
- Marcott’s hockey stick uptick mystery – it didn’t used to be there (wattsupwiththat.com)
Nick Stokes says:
March 26, 2013 at 4:19 pm
“Of course the Marcott study doesn’t tell you about warming past 1950. It was a study of the Holocene period. It used very long term proxies which do not have fine dating resolution.
For warming of the last century plus we have an extensive thermometer record. No need to look to proxies.”
I get your general point Nick Stokes but two points: 1) he did wind up with a paper on global warming since 1950 in the bargain and 2) We should be a heck of a lot more critical about the legitimacy of proxies. As with the tree rings of Mann, if their is a big decline where it is supposed to go the other way with the recent record, wouldn’t you ask yourself if the first part indeed represents what we confidently think it does?
Nick Stokes: “Of course the Marcott study doesn’t tell you about warming past 1950. It was a study of the Holocene period.” Then why is there so much ink to the right of the 1950’s in their graph as shown at the top of this article? And why did the authors, when interviewed, concentrate on the data after the 1950’s? And why have the headlines dwelt on the data after then 1950’s?
The paper obviously has a de jure and a de facto result. The official, de jure result that defenders such as yourself point to is something about the Holocene. The actual, de facto result is that things have warmed since 1950 so rapidly that it’s “unprecedented” in the last 11,000 years. When skeptics point out that the data is low-resolution data spliced with recent high-resolution data and this throws everything off, defenders say, “Hey, this paper isn’t about the present, it’s about the distant past.” That’s not the way the paper has been used or promoted by its authors, and it has nothing to do with the hockey stick graph in the top figure.
As I mentioned on CA. This paper doesn’t seem very useful for anything. The modern portion is not robust, according to the lead author, so we can ignore that. The rest of the Holocene is such low resolution and so heavily smoothed that it tells us absolutely nothing about scope and rate of climate changes during the reference period. Therefore it can’t tell us whether modern warming, such as it is, is unprecedented in any respect.
Correction, it’s useful for propaganda, that’s all.
Nick Stokes says:
March 27, 2013 at 1:46 am
True, but your very argument destroys your supposition–that today’s warmer Earth was caused by man’s influence.
During the past 11,300 years, everybody agrees we’ve had several periods of warming. They are the:
1) Medieval Warm Period
2) Roman and Minoan Warm Periods
3) Holocene Optimum.
NONE of these was caused by man’s influence–NONE! So we could just as well add the:
4) Modern Warm Period.
What’s not to like, right? Trees are growing faster, foodstuff crops are more productive–the whole biosphere is doing better overall. This current warming isn’t unprecedented at all but very much beneficial.
So your argument that we’re in another warming period similar to others destroys the very thing you want to blame it on because it’s happened several times before WITHOUT that causation!
Interesting paper by Marcott et al, Mr. Stokes–only it doesn’t necessarily prove what you think it does; it indicates just the opposite–man isn’t the problem (although in this case I suspect Mann is, sadly).
They would be negated because the current “warming” would simply be a high frequency fluctuation smoothed out by the low temporal resolution of the rest of the recon.
ferd berple says:
March 26, 2013 at 8:07 pm
Nick Stokes says:
March 26, 2013 at 4:19 pm
Of course the Marcott study doesn’t tell you about warming past 1950.
Nick,
If Marcott had simply done his work AND not added the temperature record, the paper would not have drawn arrows. He/they chose to use it to make a conclusion about CAGW issues.
Any report is just blah blah without conclusions (I’d argue recommendations, also). Truth, as James noted, has to be useful and take you somewhere to be worthy of the word. The Marcott thesis did not have the modifications and was not applicable to the conclusions. It is legitimate to jump all over the paper for what was added was targeted for the end result: CO2 is killing the planet.
Good intentions or not, the paper should be withdrawn.
Without the “spike” Marcott’s paper would have been seen as quite detrimental to the whole CAGW story, showing as it did that a significant part of the early Holocene was warmer than today.
I feel a bit sorry for poor Marcott … there appears to be some awfully naive/deceptive data adjustment in there, but it seems possible that this “spike” is perhaps not the most important part of the work he/she wanted to show, and it may have been a product of the way the work got past the ‘peer review’ process.
I’m having soooooo much fun watching Nick Stokes making a fool of himself trying to justify Marcott’s methods.
Nick, I know you’re not stupid but you’re making it hard for me to justify my faith.
Nick Stokes says:
March 26, 2013 at 9:05 pm
Marcott was doing a study of the Holocene. He chose proxies that were stable over long periods and could be independently calibrated (ie did not require overlap with historic thermometer measurements). He could not have that plus the resolution needed to detect modern warming.
Nick take a deep breath and look what coalsoffire posted above:
coalsoffire says:
March 26, 2013 at 6:45 pm
Nick Stokes in the grand tradition of the black knight, fights on….
You are pretty much making exactly the same scene again and again. It has been explained to you several times, but you still come back with the same, not answering or acknowledging what people tell you.
Nick such useless stubbornness to acknowledge the reality does not help your cause, whatever that is. Of course you may continue to entertain us if you chose so, however you can do better.
NZ Willy: Marcott’s “perturbations” are the 2nd key to his final output. After the final data were prepared, the last step was to permutate each datum 1000 times, using the age-uncertainty of that datum as bounds. Thus a datum dated 1700AD with an age-uncertainty of 100 years would be permutated into the range 1600AD-1800AD — thus its temperature value is distributed into those years. However, for the final 1940AD bin, Marcott set its age-uncertainty to zero. Therefore all those data were permutated only within the 1940AD bin. The result is that the 1940AD bin did not share its temperature values with its neighbors, and so was not flattened as were all other bins. It is just a mathematical trick which Marcotte used to guarantee that the 1940AD bin would preserve the same value after the perturbations, that it had before.
Don’t we need their code to be sure of that?
Nick Stokes: Of course the Marcott study doesn’t tell you about warming past 1950. It was a study of the Holocene period. It used very long term proxies which do not have fine dating resolution.
For warming of the last century plus we have an extensive thermometer record. No need to look to proxies.
That has been said many times and many ways: what is most noteworthy in their report is not supported by their data, and what is supported by their data would (probably) not have been considered interesting enough to gain acceptance in Science.
Nick Stokes says….:
Nick, your presentation of Marcott, et al.’s proxy data at Moyhu.blogspot.com is phenomenal. You have a gift for data presentation. Everyone should check it out:
http://www.moyhu.blogspot.com/2013/03/proxy-viewer-with-choice-of-dating-and.html
However, I’m disappointed you are unable to come to terms with exactly what Marcott, et al. did:
1. They shifted the known dates of selected cores by up to 1000 years to produce a pronounced spike in 20th century temperatures. The un-shifted data shows the exact opposite: a pronounced decrease in 20th century temperatures.
2. They deleted (truncated) relevant data from selected proxies. Had this data been included, it would have dampened or cancelled out their 20th century temperature spike.
3. They held press conferences and trumpeted their results agreed with (and vinidicated) Michael Mann’s fraudulent MBH 98 paleotemperature reconstruction.
These were all done to produce a predetermined, desired outcome. This is ‘Scientific Fraud 101’. Manipulating data to produce a predetermined, desired outcome is the very definition of scientific fraud.
As for your statement:
“For warming of the last century plus we have an extensive thermometer record. No need to look to proxies.”
Thermometer readings and proxy data are apples and oranges. Nearly all the proxy data shows recent temperatures declining. Recent thermometer readings show it rising. Grafting thermometer readings onto proxy data is just another variation of Mike Mann’s ‘hide the decline’ Nature trick. It smacks of attaching an orangutan jaw to a human skull to make scientific headlines.
I did hear a rumor that a certain public climate scientist was a reviewer for this paper and i wonder what he or she advised needed to be added ammended or altered so the paper was publishable? I’m sure to make it a better paper and all.
And look at the result. Maybe someone should ask to look at the reviewers comments?
Louis,
I’m glad you liked the viewer – thanks. On Marcott, I certainly don’t think it is a perfect paper. I’ve said many times that I don’t think they should have plotted recent results (eg 29th Cen), spike or not. Too few data and too many end effects.
But I think many criticisms are misplaced, and I say so. There’s nothing intrinsically wrong with re-dating. The original observations are of depth, proxy reading and C14 ratios at date points. The actual dating is done by programs like this. Those programs get updated – they incorporate observational data which improves. It’s very reasonable to want all data using the same (modern) version.
I don’t jump to the conclusion that this was done for some conspiratorial reason. It doesn’t even work on that level. When I first saw they spike plot I thought – that looks odd, why are there two spikes? And then, but hang on, there actually wasn’t a heat spike in 1940.
The “deletion” of data is mainly consistency. The carbon dating program won’t report dates beyond 1950. Should they make them up? In one case complained of (OCE326-GGC30), the original author had eight different readings all assigned a date of 0BP. A recon only allows one temp per time, so something had to give.
The scientific world generally does not think of Mann’s results as fraudulent. But even if you do, it’s not a sin to get results that agree with them (though I think he was referring to Mann’08).
There was a time when proxies at their modern end showed a “decline” which had to be hidden with Mike’s Nature trick. Now after some modern re-calculation of dates – an uptick appears. It appears there was no need to hide Marcott’s Science trick – it went straight to press, over the heads of the scientific community straight to the hockey Moms of the MSM.
@ur momisugly NZ Willy, please don’t give up, I appreciate your explanations of the arcane handwaving of these works in search of hockey sticks and warming.
Eventually we come to see what is blindingly obvious to you.
Thanks for persevering.
I appreciate the supportive comments I’ve had here, cheers.
JustAnotherPoster,
Isn’t the really interesting part of climate science that all the “proxies” are showing a cooling trend yet the “Temperature” data supplied by CRU and Hansen shows a warming.
Not all the proxies show a cooling trend, only some maximum latewood density proxies in the northern Hemisphere (the divergence problem).
Climate science is much more interesting when you get your facts straight.
On this issue, even as stated by you (incorrectly), ‘interest’ usually climaxes at the question, whereupon it is transmogrified into an argument against the entire proxy record. True ‘interest’ would follow up by testing that assumption. Steve McIntyre seems to think that one can answer these questions fuelled by a cup of Starbucks coffee. Doesn’t seem like much effort is needed. How about it?
Doug Proctor,
If Marcott had simply done his work AND not added the temperature record, the paper would not have drawn arrows. He/they chose to use it to make a conclusion about CAGW issues.
Please cite, after quantifying what ‘C’ (catastrophic) means, where Marcott et al made conclusions about ‘CAGW’.
Some proxy records show a downtick against the instrumental record after the 1960s/80s, while showing a fair match, in many cases, to instrumental temperatures prior. Marcott do not use proxy data past 1950 for various reasons, but it removes the troubled part of the proxy record that disagrees with the better-resolved instrumental record. Nothing wrong with that. Why include bad data?
The implied argument of many posts on the matter here, is that if proxy records go bad after 1960/80, why do we assume they are good prior to that date?
Answer: we don’t make that assumption. that’s the point of all these reconstructions, to test proxies against other proxies and, where appropriate, the instrumental data.
Non-sequiturs are not science. Does the divergence problem in the late 20th century mean that proxy data prior is less reliable than supposed?
Find out! Don’t just assume. Google scholar+key word search+reading is a good start.