Hockey Stick: Unbroken at 20

April 20, 2018

Scientific American:

Two decades ago this week a pair of colleagues and I published the original “hockey stick” graph in Nature, which happened to coincide with the Earth Day 1998 observances. The graph showed Earth’s temperature, relatively stable for 500 years, had spiked upward during the 20th century. A year later we would extend the graph back in time to A.D. 1000, demonstrating this rise was unprecedented over at least the past millennium—as far back as we could go with the data we had.


Although I didn’t realize it at the time, publishing the hockey stick would change my life in a fundamental way. I was thrust suddenly into the spotlight. Nearly every major newspaper and television news networkcovered our study. The widespread attention was exhilarating, if not intimidating for a science nerd with little or no experience—or frankly, inclination at the time—in communicating with the public.

Nothing in my training as a scientist could have prepared me for the very public battles I would soon face. The hockey stick told a simple story: There is something unprecedented about the warming we are experiencing today and, by implication, it has something to do with us and our profligate burning of fossil fuels. The story was a threat to companies that profited from fossil fuels, and government officials doing their bidding, all of whom opposed efforts to reduce greenhouse gas emissions. As the vulnerable junior first author of the article (I was a postdoctoral researcher), I found myself in the crosshairs of industry-funded attack dogs looking to discredit the iconic symbol of the human impact on our climate…by discrediting me personally.


Show us the data! oh…

Here, see Dr. Mann’s explanation of how his emails were stolen, tortured, taken out of context, distorted, and then fed back to the media. Sound familiar?


43 Responses to “Hockey Stick: Unbroken at 20”

  1. ted knopper Says:

    Mann has ridden this horse for a long time. A recent study found the sensitivity of warming is a lot less than some claim. “Our study all but rules out very low and very high climate sensitivities,” said lead author Peter Cox, a professor at the University of Exeter. MODTRAN a way to measure warming from CO2 shows the sensitivity is almost zero, about 1/3 of a degree warming from the increase in CO2 since 1600 and about half that per other studies is CO2 being released from the ocean as it has warmed a bit.

    Mann claims the earth climate is very sensitive to CO2 increases and completely ignores the increase from changes in earth tilt and orbit and solar output increases.
    In his suit against Dr. Ball he has refused to turn over all his underlying source data.
    Dr. Ball contends that Mann cherry picked the data to get rid of the medieval warm period and the following little ice age. as shown in this battle of the graphs. NASA has found the arctic was ice free from 6500-4500 BP, trees have been found in Canada from that period hundreds of miles north of the present tree line which raises questions about how accurate Mann’s graph actually is.

    Mann may be correct. The science is not settled so to pretend it is does a disservice to both science and the public.

    • greenman3610 Says:

      Every year, dozens of studies come up relating to climate sensitivity. Some claim higher, some lower sensitivity numbers.
      Over the past century, the overall results have crowded around an average of the canonical 3 degrees or so for a doubling.
      Example here of a recent study showing much higher sensitivity from Brown and Caldeira.

      Point is, the science is settled in that, it’s warming, we’re doing it, and it’s going to get bad. Since Mann’s results have been confirmed by multiple other groups using a wide range of data, including some completely excluding Mann’s data sets, the hockey stick has been more than solidly confirmed.

    • Gingerbaker Says:

      “Mann claims the earth climate is very sensitive to CO2 increases and completely ignores the increase from changes in earth tilt and orbit and solar output increases.”

      What a crock of dingo kidneys. Ted Knopper is typical of uninformed armchair amateurs who have no effing clue that climate scientists are actually really extremely competent at what they do.

      Hey Ted,

      science does know about Earth tilt, and orbits and solar output. If you had bothered to actually research the topic, instead of spewing denier talking points like a faithful tool, you would know this, as it is pretty damned obvious.

    • grindupbaker Says:

      I just read your stuff. It’s infantile crap.

  2. redskylite Says:

    Got to say that Dr Mann weathered the hostile aftermath extremely well (it could well have broken a lesser man) and is a fine ambassador to science. I’m sure Raymond Bradley and Malcolm Hughs also got plentiful negative treatment too. The Hockey Stick graph is worth volumes of words, and a great motivator for action.

    Over a dozen subsequent reconstructions have supported these conclusions.

    George C. Marshall Institute, Fred Singer and Willie Soon among the challengers – nuff said.

  3. redskylite Says:

    And this is rock solid empirical evidence of what those paleontologists found:

    What happened to winter? Vanishing ice convulses Alaskans’ way of life

    The Alaskan government recently warned this bewildering rate of change risks the physical and mental health of its citizens, citing a condition called solastalgia, the distress caused by severe disruption to the environment near home.

    “Alaska is on the frontlines of climate change,” Bill Walker, the state’s governor, warned last year. Walker, an independent, has convened a panel to come up with some sort of climate change strategy by September.

  4. L RACINE Says:

    In July of 2017 the New York published an article called “The Uninhabitable Earth” written by David Wallace-Wells.

    IMO it was an excellent wake up call for a “main stream media” publication, it was pretty well researched and a genuine attempt to wake the population at large regarding the real and catastrophic potential risk to BAU.

    I was astonished to read Mann response to this article and after some thought I came to the conclusion that his response was due to the amount of litigation he has had to suffer though. And the “need to appear” impartial….

    So Mann decides to step in to the lime light and this is what the Washington Post prints

    But, his did redeem himself and pull back on the Wash Post comments, you can hear this for yourself…. “The Doomed Earth Controversy: David Wallace Wells & Michael Mann (November 2017”. It is worth watching….

    But the damage was done… because this chat did not get Main Steam Media publication…

    Great move…. Mann…. (asshole)!!!!!!

    • redskylite Says:

      Reading the Washington Post reporting that you kindly included, I think Chris Mooney did a fair job of summarizing the story and criticism. In an ideal world the David Wallace-Wells study would have been better received and more effective as a wake-up call, but the immense effort that has gone into denial and prolonging the use of lucrative fossil fuels has conditioned many decent folk into being cautious and afraid of being labeled “alarmist”.

      • greenman3610 Says:

        It’s getting to the point where I am spending more and more time pushing back against catastrophist framing. I tell people, when I hear the “we’re all going to die, imminent human extinction” meme – “We’re not getting off that easy.”
        We, meaning humans, are going to actually have to live with, work with, adapt to, and eventually curb, climate change. I think that’s what I hear Mann saying at 25:00 above.

        • I’m guessing sites like this one probably don’t help:

          Although I do think that the reality lies somewhere between this and the (somewhat conservative) predictions of published climate scientists.

          I guess only time will tell…

          But it would be nice to see some real political conviction to do something to intervene before we have to live within these doomsday scenarios!

          • dumboldguy Says:

            Here are two more sites that I have had bookmarked for years along with Arctic News. IMO, what happens in the Arctic is key to the climate change dilemma and all three provide much valuable info.

            Methane Hydrates

            Arctic Sea Ice

            These two sites are also not much “help” to those that want to “push back” on the ever-increasing evidence that catastrophe (perhaps) lurks out there (at some unknown future point) and that we are (probably) only going to have to do one thing if we fail to “actually live with, work with, adapt to, and eventually curb, climate change” in time—-that’s die off as a species (maybe not all of us), and take the biosphere with us (but maybe not all of it) .

            Did I say that with enough “wishy-washiness” to avoid annoying the scientists who don’t want to be “extremists”? Yes, it makes much more sense to wait until after-the-fact and announce “We saw it coming but didn’t want to upset anyone with “premature exposition” of truth.

            So lets keep talking about solar roads and how EV’s are going to push Ford F-150’s off the roads while the tipping points (unknown) creep up on us and we enter (perhaps) uncontrollable positive feedback loops.

        • Sir Charles Says:

          Sure, Peter. It won’t be anything like doomsday when 10 billion people have to be fed by a rapidly warming planet. Where Climate change ‘will create world’s biggest refugee crisis’, The Economist explains, Why climate migrants do not have refugee status

          Enjoy your peaceful day.

        • Sir Charles Says:

          A third of Australia’s Great Barrier Reef is gone, probably forever. And that’s just the starter…

          Great Barrier Reef saw huge losses from 2016 heatwave

          • redskylite Says:

            The Australian newspaper trying to indoctrinate the public that “The Great Barrier Reef damage” is all a debate and the view of one man. Climate Feedback puts things right, but how many people read CFB compared to The Australian ?

            This article in The Australian covers a new study published in Nature that concludes global warming played a key role in the recent large-scale bleaching and mortality of corals in the Great Barrier Reef. Based on the comments of a single oceanographer (Prof. Kaempf), the article was headlined “Not all scientists agree on cause of Great Barrier Reef damage”.

            The scientists who reviewed this article found that this source’s comments in the story are unsupported by evidence and prior research, and therefore The Australian article misleads readers by emphasizing a “debate” that


        • L RACINE Says:

          Yeah so long as “we” wake up in enough time to stop killing ourselves and the wonderful planet we live on.

          History has shown that things don’t always “turn out well” for population and societies die.

          I don’t see any real significant signs that the population of the world, the people that emit the most green house gasses per person, are waking up and addressing the issue.

          The message, regarding the catastrophic consequences of BAU just isn’t being understood.

          I would call it willful ignorance, just saying.

        • Sir Charles Says:

          Hockey stick rather looking like a boomerang…

          Glacier loss is accelerating because of global warming

          As climate scientists predicted, glaciers are vanishing due to rapidly warming temperatures

          • dumboldguy Says:


            And have you heard about the Irish boomerang?—-it never comes back but just keeps singing sad songs about how much it wants to.

          • Sir Charles Says:

            It’s called a stick, dumbo.

            Meanwhile, your president seems to have more ambitious targets…

            In their bid to prop up the coal industry, Trump administration officials are now considering using a cold war-era law, Bloomberg reports. A senator from West Virginia urged Trump to use the Defense Production Act, which allows the president to effectively nationalize private industry to ensure the U.S. has resources that could be needed amid a war or after a disaster.

            => Trump’s Latest Plan for Saving Coal Comes From the Cold War

          • dumboldguy Says:

            WHAT is “called a stick”, Chucky (aka Irish Sir Potato Head)? It would be so much easier to talk to you if you took the time to make sense.

            And yes, the President of a minority of Americans and his rabid attack dog Pruitt ARE considering the application of the Defense Production Act to prop up “beautiful clean coal”. Truly insane, and yet another reason to fire Pruitt and impeach Trump ASAP.

          • Sir Charles Says:

            The boomerang that doesn’t come back is called a stick, dumbo. Try to remember what you’re hacking into your keyboard 😉

          • dumboldguy Says:

            No, a boomerang that doesn’t return is called a “non-returning boomerang”. Non returning boomerangs are a type of “throwing stick”.

            Of course. we wouldn’t expect a fookin’ Irishman who has been beaten about the head and shoulders too much with a shillelagh (by those who take offense at his boorishness) to understand that. In his muddled and defeated state, he is only concerned with trying to “score” rather than talking sense.

    • dumboldguy Says:

      I agree with your take, but would suggest that it is a bit unfair to criticize how a battle was fought unless you were in the same foxhole with the combatant dodging the same incoming fire.

      Mann has been attacked as much and as severely as anyone in the climate wars, has done the best he can, and is still standing and fighting. A few “assholey” missteps don’t negate that.

      • L RACINE Says:

        Yeah, I agree, but to use your analogy, when I soldier comes home with PTSD you take his “measure” and try to keep him from hurting himself and others.

      • redskylite Says:

        Not sure how much support Dr, Mann received at the time, he received dire threats against his young family and that would worry any decent man (or woman). Another scientist at East Anglia University contemplated suicide during “Climate Gate”, difficult to remain solid when your family are threatened.

  5. redskylite Says:

    Even those skeptics who reject the warning that the “Hockey Stick” foretells aren’t prepared to risk their money in their wafer thin convictions.

    If we ever reversed the problem would the “Hockey Stick” transform into an ocean wave ?

    “As many as 13% of Americans are still convinced climate change isn’t happening at all, and 30% are confident that humans play no role in it. But real estate prices now seem to confirm the chestnut attributed to author Philip K. Dick: “Reality is that which, when you stop believing in it, doesn’t go away.” Even those who don’t believe in climate change, or have never been hit by a hurricane, are nonetheless seeing an impact on their property values. That foretells inevitable and large economic impacts in vulnerable areas, but could have the broader positive effect of discouraging risky investment.”

  6. dumboldguy Says:

    Time to again trot out the best hockey stick article I’ve ever come across—-over two dozen “hockey sticks” to peruse. Then get a stiff drink, or pray, or go pull weeds—-whatever might distract you from the truth.

    C:\Users\tum\Desktop\Library\blog2009 The Graph A Picture of the Present and Future.mht

    • dumboldguy Says:

      Forgot to mention that you’ll need to cut and paste that in your browser AND that there are MANY terrific links embedded. I spent days digging around after i saw this piece

      • L RACINE Says:

        can you provide a better link to the site?? What site is it?

        • dumboldguy Says:

          Sorry, the link was to one of my files where I had compiled some references. Can’t find the original source on the web anymore, but Grigg was speaking to a piece in Special Report, New Scientist #2678, October 16, 2008 :

          The Graph: A Picture of the Present and Future
          by Ray Grigg, Shades of Green,July 5, 2009

          Some links that will get you started, although New Scientist is now behind a paywall:

          • Sir Charles Says:

            Great, dumbo. You sober again?

          • dumboldguy Says:

            If anyone is drunk here, it’s you, Chucky.

            Any reaction to the many hockey sticks in the New Scientist link? Did you look at them? Do you understand all the words? Unlike your comment, which is typical of yours in that consists entirely of one and two syllable words, there are many multi-syllabic words in the linked article—-would be glad to explain any you don’t get.

          • Sir Charles Says:

            Rather looks like boomerangs, dumbo.

          • dumboldguy Says:

            Yes, in the mind of one who refuses to accept that his joke has long gone stale, it does look like boomerangs. When is Chucky going to realize that his foolishness is a “returning boomerang” that comes back and whacks him in the head every time he throws it.

            To those who are interested in science rather than “scoring”, it is quite obvious that what we are looking at is the type of non-linear growth curve that we now call “hockey stick”. Stop embarrassing yourself, Chucky.

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