Professor Roger Pielke Jr Snaps Marcott et al Hockeystick

Posted: April 1, 2013 by tallbloke in alarmism, Analysis, flames, Incompetence, Measurement, media, methodology, Politics, propaganda
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Hats off to Prof. Roger Pileke Jr, who has followed Steve McIntyre’s lead in standing up for science in the face of continued lies and scientific fraud. Here are some highlights from the post linked above:


In 1991 the National Research Council proposed what has come to be a widely accepted definition of misconduct in science:
Misconduct in science is defined as fabrication, falsification, or plagiarism, in proposing, performing, or reporting research. Misconduct in science does not include errors of judgment; errors in the recording, selection, or analysis of data; differences in opinions involving the interpretation of data; or misconduct unrelated to the research process.
Arguments over data and methods are the lifeblood of science, and are not instances of misconduct.

However, here I document the gross misrepresentation of the findings of a recent scientific paper via press release which appears to skirt awfully close to crossing the line into research misconduct, as defined by the NRC. I recommend steps to fix this mess, saving face for all involved, and a chance for this small part of the climate community to take a step back toward unambiguous scientific integrity.

The paper I refer to is by Marcott et al. 2013, published recently in Science. A press release issued by the National Science Foundation, which funded the research, explains the core methodology and key conclusion of the paper as follows (emphasis added):
Peter Clark, an OSU paleoclimatologist and co-author of the Science paper, says that many previous temperature reconstructions were regional and not placed in a global context.

“When you just look at one part of the world, temperature history can be affected by regional climate processes like El Niño or monsoon variations,” says Clark.

“But when you combine data from sites around the world, you can average out those regional anomalies and get a clear sense of the Earth’s global temperature history.”

What that history shows, the researchers say, is that during the last 5,000 years, the Earth on average cooled about 1.3 degrees Fahrenheit–until the last 100 years, when it warmed about 1.3 degrees F.
The press release clearly explains that the paper (a) combines data from many sites around the world to create a “temperature reconstruction” which gives a “sense of the Earth’s temperature history,” and (b) “that history shows” a cooling over the past 5000 years, until the last 100 years when all of that cooling was reversed.

Here is Michael Lemonick at Climate Central:

The study… confirms the now famous “hockey stick” graph that Michael Mann published more than a decade ago. That study showed a sharp upward temperature trend over the past century after more than a thousand years of relatively flat temperatures. . .“What’s striking,” said lead author Shaun Marcott of Oregon State University in an interview, “is that the records we use are completely independent, and produce the same result.”

In a belatedly-posted FAQ to the paper, which appeared on Real Climate earlier today, Marcott et al. make this startling admission:

Q: What do paleotemperature reconstructions show about the temperature of the last 100 years?A: Our global paleotemperature reconstruction includes a so-called “uptick” in temperatures during the 20th-century. However, in the paper we make the point that this particular feature is of shorter duration than the inherent smoothing in our statistical averaging procedure, and that it is based on only a few available paleo-reconstructions of the type we used. Thus, the 20th century portion of our paleotemperature stack is not statistically robust, cannot be considered representative of global temperature changes, and therefore is not the basis of any of our conclusions.

Here are the steps that I recommend should be taken:

1) Science should issue a correction to the paper, and specially do the following:

(a) retract and replot all figures in the paper and SI eliminating from the graphs all data/results that fail to meet the paper’s criteria for “statistical robustness.”
(b) include in the correction the explicit and unambiguous statement offered in the FAQ released today that the analysis is not “statistically robust” post-1900.

2) NSF should issue a correction to its press release, clarifying and correcting the statements of Peter Clark (a co-author, found above) and Candace Major, NSF program manager, who says in the release:
“The last century stands out as the anomaly in this record of global temperature since the end of the last ice age,” says Candace Major, program director in the National Science Foundation’s (NSF) Division of Ocean Sciences.
3) The New York Times (Gillis and Revkin, in particular), Nature and New Scientist as outlets that pride themselves in accurate reporting of science should update their stories with corrections. Grist and Climate Central should consider the same.

In comments, Professor Pielke says:

I interact with climate scientists just about every day (being in CIRES, a leading global institute). There are an awful lot of people doing very good work.

There are a few bad eggs, with the Real Climate mafia being among them, who are exploiting climate science for personal and political gain. Makes the whole effort look bad.

That said, virtually all of the climate science battles are teapot/tempest affairs — climate politics and policy has moved on to issues involving economics and energy.


I have to disagree with Prof. Pielke on that last point. It is the tacit assumption that the paleoclimatology of institutions such as the Climate Research Unit at the University of East Anglia and Penn State University is inimpeachable that underpins the whole notion of “It’s unprecedented – we must act”, that has been pushed into the political and economic arena by activist groups such as Friends of the Earth and the World Wildlife Fund and Greenpeace. These organisations have infiltrated the IPCC, the civil service, the Department of Energy and Climate Change, the house of commons, and the house of lords.

As Steve McIntyre notes in the post linked in the intro, Marcott et al still haven’t ‘fessed up to the most egregious aspect of their paper, and are attempting to smoke screen the whole affair with a partial admission of the paper’s shortcomings.

The rot must be stopped, and chopped out before the disease spreads further.

  1. Scute says:

    There’s one problem there. New Scientist don’t pride themselves on accurate reporting so they won’t.

  2. vukcevic says:

    “It’s unprecedented – we must act”
    Yep, we must act to prevent return of either the Little Ice Age or even worse !

  3. Eugene WR Gallun says:

    Its no longer about science. It is about keeping the scam going as long as possible. Real science refutes CGW. so real science has been discarded. The people running this scam are no longer even trying to contend on that level. Look at the quality of the presented work.

    What it is about now is trying to keep the public hoodwinked. If the politicians feel public mood shifting enough that it endangers them to keep participating in the scam they will drop it like a hot potato. So for the scammers it is now all about publicity. Prevent public opinion from turning.

    Think about it. Is this paper any different from BEST? We are seeing a whole series of such junk science being puffed up by the media. It is no longer about science — it is about headlines.

    Understand their tactics if you wish to defeat the enemy.

    Eugene WR Gallun

  4. oldbrew says:

    ‘the 20th century portion of our paleotemperature stack is not statistically robust, cannot be considered representative of global temperature changes, and therefore is not the basis of any of our conclusions’

    So either their supposed hockey stick has a useless blade, or it isn’t one at all – April fool.

  5. JCrew says:

    I’ve seen quite a few temperature graphs from various sources for the past 2000 to 10,000 years. Most present the well known warm and cool periods. I recognize thst resolution will be different between ice cores and tree rings for paleoclimate reconstruction.

    Help me with this: it appears the Marcott et al is one almost linear line of drop in temperature over the past 10,000 years. Like Tallbloke mentioned a 1.3F drop. What I wonder is:

    1. Is this smoothed 1.3F drop real (stick handle)?

    2. If so, then a line might justifiably be drawn with confidence to present global temperature (the blade)

    Has this been the points presented by Marcott and several others? It is just if based on the same data source there is error, as presently expressed?

  6. tallbloke says:

    JCrew: Paleo records tend to smoothe out variation in the deep past due to the combination of many proxies from different locations. 30% of country by country temperature records of the C20th don’t show any warming, or show a cooling…

    Craig Loehle’s curve shows something like a 1.5C drop from Medieval warm period to the nadir of the little ice age of the C17th.

  7. ferdberple says:

    JCrew says:
    April 1, 2013 at 12:55 pm
    2. If so, then a line might justifiably be drawn with confidence to present global temperature (the blade)
    no, because there could have been many upticks (or downticks) in the past of similar size or greater size than the present that are hidden by the lack of resolution of the proxy data.

    the problem is that the claimed resolution of the Marcott et al study is about the same as the entire modern temperature records, so you cannot conclude with any confidence that similar upturns in temperature have not occurred in the past and are simply hidden by the lack resolution.

    If one averages the modern temps so they are the same resolution as Marcott et al, then our 0.8C increase in temps over the past 120 or so years becomes a single point, 0.4C lower than present temps, which is cooler than much of the past 10,000 years as shown by Marcott.

    Even the IPCC agrees that the increase in temps prior to 1950 is natural in origin, so after averaging we are left with a very small increase in temperatures that might be attributable to humans, that is inconsequential in comparison to the drop in temps over the past 10,000 years.

    If Marcott is showing us anything, it is that we are on an accelerating path to the next ice age unless something is done to reverse the process. The leveling off in temperatures during the past 16 years in spite of record CO2 levels suggests that the process leading to the next ice age may be beyond our ability to resist.

  8. oldbrew says:

    Temperature changes could also have been influenced by a recorded increase in solar magnetic activity in the 20th century.

    A Doubling of the Sun’s Coronal Magnetic Field during the Last 100 Years (1999 paper)

    The hockey stick replacement is here…

  9. J Martin says:

    Oldbrew said;

    A Doubling of the Sun’s Coronal Magnetic Field during the Last 100 Years (1999 paper)

    I wonder if Leif Svalgaard might give us his take on this ?

  10. JCrew says:

    Thanks for the replies. The discussion of the Marcott data is starting to be understood.

  11. Roger Andrews says:

    The issue Roger Pielke Jr. raises isn’t whether Marcott et al. is valid – we already know the answer to that – but whether it represents scientific misconduct. Pielke Jr. says it “appears to skirt awfully close to crossing the line”. I think he’s being nice.

    The simple fact is that when Marcott presented his results in his 2011 PhD thesis they looked like this:

    And now they look like this:

    Anyone who believes that the hockey stick in the second graph wasn’t generated by blatant data-fudging in the service of AGW should contact me about this bridge I have for sale.

    As to who was responsible for it, it would be interesting to know who reviewed the paper.

  12. michael hart says:

    I must be particularly stupid today or missing something, but the usefulness of this study only ever seems to decrease as I look at it.

    I’m looking at the map of the 73 Marcott proxies in the supplemental information.
    Figure S1 on page 3 of the pdf

    Now I imagine they were 73 real thermometers and not various different proxies. They appear sited almost exclusively at coastal locations that are representative of neither continents nor open oceans, and might be expected to experience relatively large variations as sea levels rose and fell with the ebb and flow of climate-change (there, I said it 🙂 ).

    I also note that the continental land mass of Asia does not contain any sites at all for these hypothetical thermometers. Zero. Nil. None. Rien. Cero. Null points. Failed to trouble the scorer. The same is also true for Australia.

    Ignoring the shenanigans with the data processing, how should I go about convincing myself that these 73 hypothetical thermometers could fairly be described as being representative of some equally hypothetical global mean temperature?

  13. Brian H says:

    “beyond our ability to resist” — before the CO2 Control Knob hubris, there was Bno suggestion that humanity could resist the next Ice Age short of putting Moon-sized reflectors in Lagrange orbit or the like. Kind of a pity; an all-out push to maximize atmospheric CO2 would be fun and wonderful for global economics. The very opposite of “de-carbonization”.

  14. Brian H says:

    typo …there was no suggestion …