Introducing the Marcott 9

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.


The Inconvenient Skeptic



The Inconvenient Skeptic



The Inconvenient Skeptic


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.

Posted in Anomaly and Bad Science by inconvenientskeptic on March 22nd, 2013 at 4:00 am.


This post has 9 comments

  1. It’s easy to write an anonymous post on a blog. Why don’t you have the courage to write this up and submit it to a journal for publication? You know, the way real scientists do things?

  2. Denis Ables Mar 22nd 2013

    What’s amazing to me is that these folks have the chutzpah to do such bogus analysis.

    In case you missed it, scroll down to the first video on the right side, and enjoy !

  3. inconvenientskeptic Mar 22nd 2013


    One would argue that the Marcott paper is sufficient proof that on the topic of climate change, the conclusion of the paper matters more than the science going into the paper.

    I am not alone in this either. Judith Curry has stated:

    “”To generate the blade in Science, it sufficed to ‘pull back’ in time some ending downtick proxies, and pull forward to T0 some ending upticks. It is evident from 1G compared to 4.3C that 9 were pulled back at least a few decades. We shall look at one below. It is also evident that about 10 others were pulled forward, since in Science at 1850 (100 before T0) there were still about 30 proxies in the area weighted mean, while in the thesis there were only about 20. The Science ‘blade’ was manufactured by ±time shifting proxy start/end dates to take advantage of mean dropout. Unfortunately, time shifting from reference dates with associated multiple age controls is nowhere noted or justified in the Science paper or the accompanying SI prose. It should have been.”

    If you play a rigged game, you lose. The game has been rigged a long time. Certainly if I submitted a paper that gave the opposite result it would not have been published. One has to wonder why his was.

  4. GuarionexSandoval Mar 23rd 2013

    Erwin, It’s pretty funny to see your anonymous avatar accompanying your irrelevant criticism that ignores the facts of the matter by commenting not on the truly serious problems of the Marcott paper but incorrectly on the anonymity of the blogger. Did you bother to click on blogger’s bio link? As far as what Marcott actually shows about the Holocene temperature record, I’ve known about this falling temperature trend for years. Anyone who has bothered to follow this over the past couple decades are well aware of this. The Greenland ice core temperature data alone demonstrate this.

  5. inconvenientskeptic Mar 23rd 2013

    Sadly anonymity can be important. There was one reader who wasn’t that ended up in trouble for commenting on a skeptic site when trying to get a job. They found his comment on Google and said they didn’t hire deniers.

    He kindly asked me to scrub his name which I of course did. That is really a sad state of affairs. So I don’t begrudge anonymity here.

    Erwin does resort to degrading the opposition and fails to point out any flaws with the data I have presented or the analysis of the Marcott paper. That would be a more constructive approach to be sure.

    Honest opposition always improves the quality of an analysis. It is that honest opposition that is not allowed in the climate debate as warmists instead simply try to denigrate those that point out flaws in their theory. The theory of global warming is deeply flawed, but they are unwilling to be honest about it.

  6. mike Abbott Mar 23rd 2013

    inconvenientskeptic: Just to clarify, Judith Curry did not make the statement you attributed to her in your above reply. That statement was made by Rud Istvan in a guest post on Judith’s site. In her comment below the post, Judith says “Again, I am not personally digging into the science aspects of this study, although I find the sociology of what is going on here very interesting.”

  7. inconvenientskeptic Mar 23rd 2013


    In one of the discussions I am part of someone attributed it to her site, but it looks like I misinterpreted the site as her. Sorry about that. I accept the correction. 🙂

  8. mrsean2k Mar 24th 2013


    “It’s easy to write an anonymous post on a blog.”

    Not that easy, apparently.

    John has put his name in the “Buy Now” advert at the top right of the page, his biographical details under the left hand menu, labelled with “John’s Bio”, and which leads to his biographical details and full name (and which is repeated at the bottom of the page).

    So as far as maintaining anonymity is concerned, I’m sorry John, but you’re an incompetent, unlike Erwin of course.

    But Erwin, ignoring speculations on motive for the time being, do you challenge the characterisation of these data WRT the lack of an uptick, and their relevance to the reconstruction?

    If so, why? Be specific.

  9. “Sadly anonymity can be important. There was one reader who wasn’t that ended up in trouble for commenting on a skeptic site when trying to get a job. ”

    That’s exactly why I have been ‘Klem’ for several years now. I encourage my children to remain anonymous on the web as well. You never know how a comment made 40 years or more in the past could somehow be used against you. The internet is forever.


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