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)
NZ Willy makes a good point. The Monte-Carlo procedure they use essentially smooths out the central part but acts like a skipping rope fixing the end point at a 1940 high. Marcott then interpolates all proxies to a 20 year time-base. I think it is always wrong to interpolate proxy data because any scheme that increases the time resolution over that of the actual measurements is bound to introduce biases. In other words Marcott generates pseudo-data instead of using the measured data directly.
The best you can do is to make a time histogram of the measured data with fixed time binning. I did that for a 50 year binning and there is no uptick in the data. see : http://clivebest.com/blog/?p=4790 !
Steve Mosher says, “yes we have a good thermometer record. So, lets see how good the proxies are? after all if they cant get the present correct, what good are they for the past”
Surprised that you got into that issue. By my understanding a) these proxies can be independently calibrated and b) their resolution in most cases is greater than the length of the modern era. Accordingly overlap is unnecessary and inappropriate.
I fear that Nick Stokes finds himself on the correct side of this portion of the Mrcott debate and I do hope you’ll set me straight.
Espen says: March 27, 2013 at 12:53 am
“Nick Stokes, to compare the instrumental record to these proxies, one should use a 300 year (or so) moving average.”
We know the temperature history of the last century plus. There’s no reason to pretend we don’t because of the low resolution of some proxies.
It’s true that the Holocene story has to be interpreted carefully in the light of that low resolution. Marcott et al in their abstract said:
“Current global temperatures of the past decade have not yet exceeded peak interglacial values but are warmer than during ~75% of the Holocene temperature history.”
And the press release, reflecting that, was headed:
“Earth Is Warmer Today Than During 70 to 80 Percent of the Past 11,300 Years”
Neither of those statements would be negated by high frequency fluctuations.
Give them the modern temperature data. Tack it on to the proxies. But then smooth working backwards from the present day. Do it for three hundred year intervals. So the average temperature between 1713 to 2013 would be one data point. 1413 to 1713 another. 1113 to 1413 another etc. In that way all data periods would be smoothed equally.
Of course, doing it that way would make it all too obvious that even if we have had a minor uptick in temperature for fifty years or so — that it has really been nothing but “weather”. All those other 300 year periods probably had just as much internal variance that averaging also eliminated.
It seems to me if the intent of that paper was to study the long term temperature record over many thousands of years that would be how you would do it. You would go out of your way to avoid getting into the hockey stick controversy.
It also seems to me that if your real intent was to create a hockey stick you would do it like those clowns did. That paper is not about long term temperature. It is all about creating a hockey stick and grabbing headlines..
So they lie when they say this is a study of the earth’s temperature over the long run. No such thing. That is window dressing. The paper is about creating a hockey stick. The proof is that all this controversy could have been very easily avoided — and instead they went out of their way to create the controversy.
Motive is obvious here. These are corrupt people.
Eugene WR Gallun
ckb says:
March 26, 2013 at 8:20 pm
If the data from the proxies since 1950 do not match the observed temperature record, how useful can these proxies really be??? Isn’t this good reason to throw them out?
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Spot on. Personally, I attach next to no worth to proxies/proxy reconstructions due to uncertainties and errors. Most proxies respond to the environment in which they are living and whether that current environment is or is not favourable to them. Temperature is but one facet of environmental conditions and it is a near impossible task to isolate response solely to temperature.
This is the same point with Mann’s hockey stick where post 1960 tree ring proxies showed declining (not rising) temperatures. . It goes to proxy tuning (ie., it indicates whether the proxies have been well tuned or not to what we think that we know about temperature with a reasonable degree of certainty and it goes to proxy worth (whether the proxies validly seperate the temperature signal from their response to environmental conditions in general, ie., whether they are good temperature indicators). In teh case of Mann’s tree ring proxies which showed a decline in temperatures post 1960, Mann immediately knew from this the following:
1. If the post 1960 thermometer record was accurate, since the tree proxies were not showing a response consistent with the thermoter record, either there was a temperature tuning problem, or that his proxies were not seperating a response to temperature from a response to environmental conditions in general; or
2. If his proxies were well tuned and were validly seperating the response to temperature from the general response to environmental conditions in general, then the post 1960 temperature record was wrong (eg., possibly due to contamination from UHI or corruption from erroneous adjustments made to raw data).
If the former, the proxies should have been thrown out.
The same applies to Marcott. If his most recent proxies do not match the current thermometer record, there is either a problem with proxy tuning, or proxy worth or the current thermometer record. Given the low resolution of these proxies (and their smoothing trend) the fact that the mosts recent proxies do not show post 1950 warming tells us little about either proxy tuning or proxy worth. But is does tell us that it is wholly unacceptable to splice on the current thermometer record. It is always unacceptable to splice results from one proxy data series onto another and proxy data record and suggest that that somehow gives apicture of the whole. It does not. But it is especially inappropriate when the main proxy record is showing devivergence from the record that one wishes to splice on.
What Nick Stokes seems to overlook is that we do not know what the thermometer record would show if it went back further in time. It is quite conceivable that if it did go back further in time it would show a MWP say 1.5 to 2 degC warmer than today, Roman and Minoan warm periods say some 2.5 degrees C warmer than today and a Holocene Optimum some 5 degrees warmer than today. It might show that current temperatures are cooler than say 75% of the Holocene and that in the past there were periods with much greater and rapid warming/temperature changes. He (appears to me) to think that we can look at Marcott and accept that data as an accurate account of temperatures during the Holocene prior to about 1950. So from Marcott we now have a good temperature record of past event. We can then use the thermometer record (which ‘we’ know to be ‘good’) to put Marcott in context and to consider how today’s temperatures fit into the overall shape of the Holocene. We cannot. It is an invalid comparison. We need to come back in 300 to 500 years time and look at Marcott’s proxies for the period post 1950. When this is done, it may well be that those proxies would show no 1950 – 2020 warming, possibly even a cooling. If that is what they show then we would have a much better indication to what extent Marcott’s proxies were properly tuned and/or had worth. We might conclude from that the Holocene stick is rather depressed and that it should have showed more past warming but did not due to problems with the proxies.
Nick can’t enjoy making a fool of himself. So why does he do it?
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Nick Stokes says
“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”.
Nice try, Nick. You have a real gift for misdirection.
Have you ever considered a career as a magician, or perhaps even, a conman?
The bottom line here, is that without the spike at the end, this paper would never have seen the light of day.
Marcott’s rider about the spike being “unreliable”, is simply a fig-leaf to cover his embarrassment about that!
The proper names for the axes of a 2D map are ordinate and abcissa indicating the dependent and independent variables that are not necessarily ‘X’ or ‘Y’.
I still think not enough attention has been given between the glaring difference between Marcott’s original thesis and his subsequent paper.
Someone in the Global Warming Industry is responsible for the Hockey Stick being grafted on and then for the careful orchestration of the warmist section of the world’s media to trumpet the ‘proof’ that Mann was right all along.
While there is clearly a lot of statistical fraud/misinformation in Marcott’s paper, it is the grafting on of the Hockey Stick which most worries me.
I suspect Marcott is only a puppet here, we need to find the puppeteer.
@ur momisugly NickStokes 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.
Hmmmmm
Nick Stokes: How can they compare the last decade to the last 1000 decades when they don’t have the necessary resolution? If temperatures drop again over the next 50 years, 5000 years from now scientists using similar methods will only see the LIA when they look at their proxy reconstruction for the year 2012.
So the temperature goes up, the proxies go down.
So the proxies don’t reflect temperature when we can measure temperature, so why use them when we cannot?
Please do not be discouraged! There are a number of us who read your posts here and I believe at CA, and said to ourselves; ‘excellent point and great spotting of tricky methods’. I, for one, appreciate your insights.
Ann Banisher says:
March 26, 2013 at 10:43 pm
For those of you that are saying that reconstructions are not needed for the modern period because we have accurate temperature data, the obvious reason is that you are comparing apples to oranges. The other reason is that reconstructions have a tendency to smooth the yearly/decadal spikes that occur in the temperature record.
I’ll bet when the modern temp record gets smoothed on a century scale that the modern spike disappears.
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Indeed it does, Ann. http://suyts.wordpress.com/2013/03/11/the-dagger-in-the-heart-maybe-a-remedial-explanation-of-marcotts-hs-blade-mikey-whats-that-about-a-dagger/
“…we can’t be sure there aren’t any abrupt global warming blips…”
Oh yes, very definitive scientific statement. A simple, “We don’t know” would’ve sufficed.
“…high resolution proxy climate records…”
“…if abrupt global warming events happened in the past, then we might expect these local records to show them…”
“…but my sense is they don’t…”
Another firm “not robust” scientific statement.
—First the smoke by referring to ‘undefined other’
—Then the diversion with ‘possible’
—Then the coup de grace, a swap to a very vague, maybe if forced to, undefined ‘wager’.
What is that a bet on? That the Holocene has global events like today? Or not?
Want to buy a car? It is a used car, maybe; but if I have to, I’ll wager not abused, if the records might not have high enough resolution…
Inferred
Assumed
Supposed
Modeled
Perturbed
on and on an on
I’d like to see/hear/read Proved! When the CAGW team says ‘Robust’, they mean it isn’t solid proof and they want us to move along and not look closely as the details are maybes mights and beliefs. When that same team says “Not robust”; just whatin’ell do they mean then? Fractured Fairy Tales comes to mind…
Here’s a direct analogy:
I bought my car in 2009. Every few months I write down the average fuel economy as recorded on the dash and reset it. This is the low resolution proxy data. It varies slightly based on whether I was driving around town or taking a trip, whether it’s winter or summer, and I can see the drop in mileage from that time the alignment was really off, but usually it’s around 22MPG.
Today, while driving on the highway, I reset the average and watched it climb to about 35MPG.
My conclusion from this cannot realistically be that my car has suddenly experienced a leap in fuel economy. Obviously, that would be a ridiculous conclusion. This is exactly the same as looking at long term low resolution temperature proxies and attaching a short term instrumental record to it. And honestly, I can’t even imagine any sane individual thinking you can do that and get any sort of meaningful result.
Correction: not a scientifically meaningful result. I could get a decent “political” result…
False analogy. Better analogy. Proxies are like using a magnifying glass to look for bacteria. Eureka says the boy, none exist! Then along come telescopes and they find them.
Both are looking for the same thing. Your analogy says the proxies are not looking for the same thing as the temperature records. I think most Climate scientists would disagree with you.
Reblogged this on Climate Daily.
I think NS represents the awful poor state of primary and secondary education science in Australia which has been extended into the higher education area and people are given virtual degrees LOL
Nick Stokes, always the optimist.
Not anything to say re: Marcott et al but I did read John Kehr’s book “An Inconvenient Skeptic” and really enjoyed it. Any body else have a positive opinion?
The paper was mostly about the Holocene?
Baloney. Run on a cubic spline fit on Marcott’s (date-adjusted) Holocene proxies that preserves all the datapoints within 200 years and you get +2.0C in the Holocene. Change it to 20 years as Marcott’s temperature stack uses and you still get close to 2.0C (as well as other known climate changes such as the 8200 BP cold spike etc).
Somehow Marcott got 0.4C in the Holocene with this ridiculous method and no MWP and no LIA and an artificial 0.9C CO2 spike at the end. A flat line pointing down with a blade at the end. I wonder what well-known shape he was trying to get.
When I click on the Nick Stokes app link (nice work Nick) I see temperature proxies with a noise level of +/- 1.0 deg C and a gentle long term drop toward the present. Who would ever consider using this data set in a PhD thesis let alone publishing it in a major rag? All it proves to me is that the temperature proxies Marcott used are worthless (not enough signal, too much noise). Oh, and no hint of a hockey stick 😉
Another treatise on the Shakun Bake paper. When seeing the actual data in this naked way, one wonders how he would set about creating the stick blade. Man, these guys sure aren’t daunted or held back by scruples.