At the Blunt End of the Hockey Stick: Q&A with Michael Mann

Mann's global warming graph was dubbed "the hockey stick" by a colleague at Princeton.

A reluctant combatant in the “Climate Wars” has learned to embrace the role

Michael Mann, the climate scientist, not the movie director.

Anti-intellectualism isn’t a new phenomenon in America. But the current war of words over climate science has taken on the tone of a religious war. Comments on this very blog often testify to that. As some scientists have discovered, the war has escalated beyond words, to tactics that include espionage, intimidation, and even attempts at prosecution.

For several years, Michael Mann has been on the front lines of this conflict. Though he says he finds himself a combatant more by conscription than enlistment, the Penn State climatologist has made it the subject of his recent book, The Hockey Stick and the Climate Wars.

It was partly Mann’s work that created one of the first battle fronts in the climate wars, the now famous (or infamous, depending on which side you’re on) graph known as the “hockey stick,” which appears to document the impact of industrialization (read that: burning of fossil fuels) on global warming. The graph was featured in Al Gore’s documentary, An Inconvenient Truth, and was assailed by some as misleading.

Mann's global warming graph was dubbed "the hockey stick" by a colleague at Princeton.

Though the Hockey Stick was largely vindicated by the National Academy of Sciences and others, Mann had already become a target of climate contrarians when he surfaced again in the series of emails hijacked from a British university in 2009. The (CRU) email threads were used to again attack the mainstream of climate science, in an episode that some came to call “Climategate.” It was an unfortunate, if inevitable term, as it presumes some kind of wrongdoing and cover-up by scientists, where subsequent investigations have found none.

Recently I had a chance to sit down with Mann at a major science meeting. I wondered what Mann thought about the recent skirmish over climate scientist Peter Gleick’s admission that he had used deception to get insider documents from the Heartland Institute. Turns out he has sympathy for both.

Miller: Gleick says he succumbed to frustration over the corporate disinformation campaign to undermine climate science. What’s your reaction to that, and to Heartland’s campaign to bring down Gleick and the Pacific Institute since?

Mann: Peter is the first to admit he showed poor judgement here. And as someone who has had [my] own emails stolen and words twisted and misrepresent, I feel for the Heartland Institute folks—to a point. But I think we have to recognize that there isn’t quite a moral equivalency to what Gleick did and what the criminals who hacked the CRU emails did.

In the latter case, there was no impropriety revealed, just a cynical attempt to misrepresent and smear honest scientists, and it was used as part of a coordinated effort by vested interests to derail any progress in Copenhagen toward reaching a meaningful agreement to reduce global carbon emissions. In the former case, with Heartland, what was revealed…simply amplified what we had already known, that Heartland was part of an industry-funded effort to mislead the public about climate change. What was particularly revolting was the campaign afoot, revealed by the stolen documents — that is, the numerous documents whose authenticity Heartland has not denied — to mislead our children by inserting anti-scientific climate change denial propaganda into K-12 classrooms around the country. This is especially pernicious given that it is our children — and grandchildren — who will see the most damaging impacts of climate change if we do not choose to act now.

(Ed. Note: Heartland claims that at least one of the published documents was a forgery and has created an entire website to put forth its own version of events)

Miller: With all this “warfare” going on, how do you get any science done?

Mann:  Well, it was difficult for me to explain to my colleagues in the department of meteorology at Penn State why there was police tape over the door to my office one day. And that was because the FBI had to come in and take away a sample from an envelope that I had received, a white powder in an envelope. They sent it away to a lab. Eventually the results came back. It was corn meal. It was an attempt to intimidate and scare me but it wasn’t a hazardous material.

And I’ve had, you know, nasty emails and letters and phone messages threatening me, thinly veiled threats against my family.  If you name it, it’s pretty much happened to me and many climate scientists who now find themselves at the center of this, the attacks by powerful vested interests who are pretty comfortable with our current addiction to fossil fuels and don’t want to see change. And they’re fighting hard to try to make sure it doesn’t change.

Miller: I’ve heard many scientists lately lamenting what they perceive to be a general hostility toward science in America of late.

[module align=”left” width=”half” type=”pull-quote”]”We’ve reached a point where science is just another way of waging politics.”[/module]

Mann: Yeah, it’s a very disturbing development. We sometimes talk about the politicization of science, but…I think what we’re really talking about is the scientization of politics. Something in some sense even worse. We’ve reached a point where science is just another way of waging politics, the abuse of science, the misrepresentation of science.

And to me, that’s very disturbing because we rely upon being informed about society-relevant science and technology to move forward. I mean, it’s what grew our economy. It’s what has allowed the U.S. to be [one] of the leading industrial nations.  And for us to now have evolved to a point where there are many at the highest levels of our political system who take what can only be characterized as an anti-scientific view — the rejection of science, whether it be the science of climate change or evolution or, you know, stem cell research, what-have-you. I think that’s very troubling. I think it’s part of a larger sort of poisoning of our public discourse that we have seen in recent years.

Miller: Any regrets about your chosen career path at this point?

Mann: When I look back and ask myself, you know, where am I now, and where would I have been, I can’t imagine anything more important that I could be doing with my life than talking to the public about what, frankly, may be the greatest threat that civilization has ever faced: the challenge of dealing with human-caused climate change — and to be in a position where I can inform the public dialog about that problem. I was a reluctant entrant into the public debate over climate change. But over time, I’ve grown to embrace the opportunities that that’s given me to talk about this issue.

Here are links to two independent reviews of Mann’s book, a sympathetic one from the British newspaper, The Guardian, and a relatively unflattering one from The Wall Street Journal. The Guardian also published a series of “edited extracts” from the book.

At the Blunt End of the Hockey Stick: Q&A with Michael Mann 24 March,2012Craig Miller

15 thoughts on “At the Blunt End of the Hockey Stick: Q&A with Michael Mann”

  1. The hockey stick has been shown to be faulty statistics using faslified data.  Why is this fraud allowed to continue? Mann is the singular most responsible for poisoning public discourse.

    1. Shown by whom, where?

      You are entitled to your own opinions, but not to your own facts.The records of global temperature since the late 19th century are publicly available. If you don’t like his graph, do your own. But don’t come crying to me if it turns out to be exactly the same shape.

      This determined attempt to ignore climate change is not only childish and stupid, it shows a basic lack of faith in our economic system. Given the correct incentives, we can drastically reduce our carbon output while maintaining or increasing energy supplies.

      1. In Mann etal  ’09, the author projects the “hockeystick” temperature graph onto the globe as a temperature map to show the differences between the MWP and the LIA, and then contrasts them with the temperature of today, as represented on the blade (of the hockeystick). 

        The interesting thing is in Fig.2, the map for the MWP (950 to
        1250 C.E.). It shows California, and particularly Southern California, as cooler than average;  defined relative to the 1961–1990 reference period.
        Up to .7 degrees C colder than the 60’s and 70’s, from the exact area where Mann collects his tree ring cores.
        Right next to the MWP map Mann plots the locations of the various temperature proxies, also showing the relative weight given (ie: how large an area he projects their temperature to influence). In almost ever case (all of the ice cores for instance) the non  tree-ring proxies show an above average temp, but strangely are bracketed and flanked by abnormal low temps conjured by Dr Mann to fill in areas where there are no data. Except for Dr. Mann’s personal proxies, the tree cores from White Mountain.

        Fortunately the area he claims didn’t have a medieval warm period is one of the most studied spots on Earth, with a long document trail showing the effects of the MWP on California alpine lakes, river sediments, and tree-lines.  I was going to provide a few links but what the heck. We have the complete PBS investigative team at our disposal. I’m sure they have the Californian library of natural history on speed dial. 

        The key question is was there a medieval warm period in California? The ancillary question for Micheal Mann is why doesn’t your hockey-stick graph show California with a medieval warm period?  I’m sure Craig Miller can do the follow up.

        So the question ” [the hockey-stick is a fraud] Shown by whom? Where?” is answered,
        By Michael Mann himself. In the pages of Science magazine.

        1. “I was going to provide a few links but what the heck.” What the heck, you didn’t!
          And your last conclusion is far-fetched indeed.

          1. My thought was to spur Craig Miller into remembering that there is a difference between being a journalist and being a sycophant. 
            His fawning softball questions are nauseating, but they do open a window into Mike’s character. If you don’t kiss Mike’s butt, he won’t give an interview. And ain’t it nice how a twitch like that, from a reprobate institution like Penn St. gets to pick and choose the what and wherefore of the discussion. I am assuming that is what happened. 

            In that vein of thought I urge Miller to dig beyond the surface, to go beyond the “casual googling” that was all Bojan needed to ally his worries and doubts (if he ever had them to begin with – which I doubt).

            So you want some links?  You want some answers? 
            Did California experience the medieval warm period?

            Anderson, R.S. 1990. Holocene forest development and paleoclimates within the central Sierra Nevada, California. Journal of Ecology 78: 470-489.Graumlich, L.J. 1993. A 1000-yr record of temperature and precipitation in the Sierra Nevada. Quaternary Research 39: 249-255.Graumlich, L.J. and Lloyd, A.H. 1996. Dendroclimatic, ecological, and geomorphological evidence for long-term climatic change in the Sierra Nevada, USA. In: Dean, J.S., Meko, D.M. and Swetnam, D.W. (Eds.), Proceedings of the International Conference on Tree Rings, Environment and Humanity, pp. 51-59.Lloyd, A.H. and Graumlich, L.J. 1997. Holocene dynamics of the tree line forests in the Sierra Nevada. Ecology 78: 1199-1210.Scuderi, L. 1993. A 2,000-year record of annual temperatures in the sierra Nevada Mountains. Science 259: 1433-1436.Yes. And it was an average of 3.5 degrees warmer than today.

          2. I’ve seen your ‘like’ below Russ Steele’s commentary. Is it safe to assume you liked his distortion of facts I commented on? Seems so, since you played the same trick on me to make it appear I resort to ‘casual googling’ for all my doubts and concerns. However, it was quite clear I was refering to the credibility of Wegman’s report, where you can quickly ascertain that:- he confessed he is not an expert in climatology and even made fool of himself when commenting on the greenhouse influence of CO2;- he used passages from other works, slightly corrected to give the impression that climate science is not as sound as we would like to believe.

            So ‘casual googling’ is enough in this case. Now what about your links? Funny thing, I didn’t even need to google. First it’s quite clear the papers are refering to Sierra Nevada and not the whole California. And what do I find in Mann et al. 09? Strange coincidence, there is an orange spot right in the area of Sierra Nevada. Did you hope I wasn’t going to check on this?

            (Risking to state the obvious, you do realize that when paper says “Sierra Nevada, California”, it means it applies to Sierra Nevada IN California and not Sierra Nevada AND California, right? Very important distinction and very much needed since there is also Sierra Nevada in Spain.)

            “The ancillary question for Micheal Mann is why doesn’t your hockey-stick graph show California with a medieval warm period?” You’re kidding, right? Original hockey-stick graph is based on the hemisperic average. Now California (well, only Sierra Nevada, remember) is big, but the world is much bigger still.

  2. I found this article after searching for FBI Gleick because it is about time these climate “scientists” were shown that they are not above the law. And what do I find? Mann moaning about white powder.

    OK, I can’t condone that kind of behaviour as two wrongs don’t make a right, but when a group of people fraudulently create a scare about the climate with the clear intention of furthering their own careers and lining their pockets … and they get away with it … they even get applauded for breaking by trying to hide FOI information or outright theft like Gleich.

    What principle applies? It is the ice-berg … that the skulduggery we can see is only a fraction? Or is it that if one climate “scientist” is prepared to break FOI laws, and another steal information and forge documents … that the PRECAUTIONARY PRINCIPLE … means we should assume they are all up to it unless they can prove otherwise?

    1. You’re begging the question. What fraud?
      I didn’t see any proof of that rather serious charge in your message.

    1. Really?  You have got to be kidding. The Hockey Stick eliminated the Medieval Warm Period. Now we know that the MWP was a global event and it does not show up in Mann’s model. This raises the issue of validity of the Hockey Stick.  

      The Daily Mail (UK) reports:Current theories of the causes and impact of global warming have been thrown into question by a new study which shows that during medieval times the whole of the planet heated up.
      It then cooled down naturally and there was even a ‘mini ice age’.A team of scientists led by geochemist Zunli Lu from Syracuse University in New York state, has found that contrary to the ‘consensus’, the ‘Medieval Warm Period’ approximately 500 to 1,000 years ago wasn’t just confined to Europe.In fact, it extended all the way down to Antarctica – which means that the Earth has already experience global warming without the aid of human CO2 emissions…

      1. “The Hockey Stick eliminated the Medieval Warm Period. ” Wrong again. Mann’s reconstructin – and about dozen others – just showed that MWP was milder than first projected by Lamb study. And there isn’t consensus that it was confined to Europe.
        “Which means that the Earth has already experience global warming without the aid of human CO2 emissions”
        Not in the last 2000 years. And even if so, this would not prove we’re not changing the planet currently.

  3. Craig,

    You wrote “Though the Hockey Stick was largely vindicated by the National Academy of Sciences” Quite the contrary of Mann’s claims. that is not what the report said. Mann’s hopeful thinking and distortion of the facts just do not hold any merit. Read the report and you will see that  three independent statisticians, chaired by an eminent statistics professor, Edward Wegman, chairman of the U.S. National Academy of Sciences committee on theoretical and applied statistics, resoundingly upheld criticism of “hockey stick”. The Wegman report, which was submitted to the U.S. House of Representatives energy and commerce committee in July, stated McIntyre’s and McKitrick’s critical analysis Mann’s methodology were “valid and compelling.”  In other words the “hockey stick” is the result of some bad science.  It is really bad science when Mann refuses to releae the data and the methods he use to arrive at the “hockey stick.” Replication is the holy grail of good science and Mann refused to let a third party replicate his analysis is a sure sign he has some thing to hide.  You were taken in by not doing your home work! 

    1. Just the same old tired mantra again. If homework entails reading contrarian web sites and not looking further, then I concur: Craig failed to do his homework, while yours deserves the best marks. Almost every single sentence is wrong, but the most disturbing one is implicit distortion (very nicely done, btw) by making it sound like Wegman wrote NAS report, which he didn’t, of course; it’s a completely different one. As for the credibility of his report, enough is written about it and demands only a casual googling. Furthermore, Mann never refused anybody to replicate his work. No article can pass a peer review process without a complete description of analysis done and data was made public from the very beginning, except the source code that was shared later and was not even necessary for replication.

Comments are closed.


Craig Miller

Craig is a former KQED Science editor, specializing in weather, climate, water & energy issues, with a little seismology thrown in just to shake things up. Prior to that, he launched and led the station's award-winning multimedia project, Climate Watch. Craig is also an accomplished writer/producer of television documentaries, with a focus on natural resource issues.

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