Climate scientist Michael E. Mann and the hockey stick graph -

Climate scientist Michael E. Mann and the hockey stick graph

Q & A on his new book, The Hockey Stick and the Climate Wars: Dispatches from the Front Lines


For the past two decades, Pennsylvania State University climate scientist Michael E. Mann has been front-and-centre in the climate change debate—and has faced vicious attacks because of it. As lead author of the infamous “hockey stick graph,” a dramatic representation of estimated temperatures stretching back 1,000 years that shows a sharp uptick this last century, Mann became a target of those who sought to discredit his work. In is new book, The Hockey Stick and the Climate Wars: Dispatches from the Front Lines, he describes doing battle with climate change deniers. Mann spoke to Maclean’s from Washington, D.C.

Q: What was the hockey stick graph, and why did it become such a flashpoint in the climate change debate?

A: It was this graphic my co-authors and I published back in the late 1990s. We only have about 100 years of widespread thermometer measurements, and know it’s warmed about one degree Celsius over that time frame. But to get an idea of how the climate has varied naturally in the more distant past, one needs to turn to indirect measures of climate. So we were working with so-called proxy data, like tree rings, corals, and ice cores, because it’s only with indirect measures of climate that we can get an idea of how climate changed in the distant past.

The picture that emerged was this descent from the relatively warm period of the Medieval era, into the cold of the little Ice Age of the 17th to 19th centuries, followed by this dramatic warming of the past century, which took temperatures outside of the range of anything that we had reconstructed in the past. We realized that the warming trend in modern time appeared to be unprecedented as far back as we could go, which was 1,000 years. In more recent years, researchers have extended these estimates further back in time—almost 2,000 years, in several cases—and the same picture emerges. The recent warming appears to be without precedent.

It was as we began to analyze the data that this so-called hockey stick emerged, the blade being the abrupt modern warming.

Q: What kind of reaction did you get?

A: The hockey stick graph became an icon in the climate change debate in substantial part when featured in the 2001 United Nations [Intergovernmental Panel on Climate Change] report. It’s visually compelling: for the public, you don’t need to understand the physics of how a climate model works to understand what that graphic is telling you. That has made it a particularly dangerous scientific result to those who seek to deny the problem, so they targeted it specifically. I became very much an accidental, and certainly reluctant, public figure in the debate over climate change, and I found myself in the centre of it. It was only later that I fully appreciated what was actually unfolding.

Q: What sorts of attacks did you face?

A: It’s hard to even keep track. I’ve been accused of having perpetrated a fraud by prominent politicians like James Inhofe and Joe Barton. I’ve had death threats against me. I received an envelope a couple years ago with a white powder in it: I had to have the FBI send it off to their lab to make sure I hadn’t been exposed to anthrax. I’ve been attacked in just about every way imaginable, whether it’s by climate change deniers, advocates for fossil fuel industry, powerful politicians, right-leaning media outlets in the U.S. and abroad. I’ve been called all sorts of nasty things; I’ve been accused of fraud; I’ve been called a criminal. It’s using the tools of character assassination—to discredit the science by going after the scientists.

Q. Good science is built on healthy debate. How can you tell the difference between that, and an attack that’s below the belt?

A: Skepticism is an essential thing in science. Scientists are expected to support their results with solid reasoning, and solid data, and their findings have to be subject to replication by other scientists. It’s all part of the give and take, and sometimes it’s rough-and-tumble. Scientists can be brutal, but as long as it’s an honest debate, that’s what moves science forward. Unfortunately, in the areas of science that have become politicized, there are those that exploit that culture of open debate by engaging in bad faith attacks. There are usually telltale signs, like going after the researcher rather than the results. Many of those looking to discredit mainstream scientific findings or individual studies like ours are not participating in the normal scientific process. They’re not going to meetings, giving lectures, or taking questions from an audience. They’re not publishing in peer-reviewed journals. They’re issuing attacks in op-eds in newspapers, or on websites with no degree of critical quality control.

Q: Other than discrediting your specific study, what, in your mind, is the larger purpose of attacks like this?

A: The motive is to create an air of controversy: to make it seem like this entire area of science is too controversial for the public to trust the findings of the science. And it’s intended, I think, to make [scientists’] lives more onerous, so that I and other colleagues attacked in this way find it more difficult to advance our science—to actually continue to do research in this area—because we’re saddled with vexatious legal assaults and attacks we need to respond to on a day-to-day basis. We worry that perhaps it’s intended to dissuade younger scientists from even going into this field.

Q: Do you think the attacks could actually discourage scientists from pursuing research like yours in the future?

A: It’s of course my concern. You can never know how many of my colleagues won’t talk to the media, or lecture about climate change, over the fear of being vilified. It’s hard to know how many have been influenced, but [the tactic has] backfired, to some extent. Scientists don’t take kindly to being misrepresented, having their work distorted unintentionally; we scientists can be a cantankerous and stubborn group. I think we’ve seen in recent years real signs of fight within the scientific community, and especially among the younger scientists. Younger scientists are far more involved, whether through social media or other means of participating in public discourse and defending science from attack.

Q: What’s motivated you to continue with this work?

A: Confronting the challenge of climate change is often framed as a scientific, or political, or economic issue. Not often enough is it framed as what it most truly is: an issue of ethics. I have a 6-year-old daughter. To me, it’s very much a question about the planet we leave our children and grandchildren. Decisions we make will impact earth for decades and centuries to come. We have to decide what sort of legacy we want to leave our children. It isn’t futile; it isn’t too late. There’s a lot of pessimism, and the problem is urgent, but there’s still time to confront it.

Michael Mann tweets from @michaelemann


Climate scientist Michael E. Mann and the hockey stick graph

  1. There are millions in the world of science and only dozens of climate change crisis protesters and this proves scientific exaggeration of climate change “crisis”.
    Nothing could be worse than a climate crisis and nobody acts like it’s a crisis. Therefore exaggeration is proven!
    Exaggeration trumps any consensus. No meaningful consensus, no crisis.

    • When the people who study these things their entire lives are almost entirely in agreement and bickering only over differences concerning progression and timing, it is of no import what those with conflicting interests think concerning said progression and timing.

      Their opinion is only relevant in so far as how to adjust, and if they have become a roadblock to ethical action then they are to be ignored. It is only logical given the circumstances.

      Harsh perhaps, but a simple truth. Scream at the sun all you like and it won’t change one iota.

      Unlike politics or culture, science is not a matter of lay-opinion, but of the presentation of viable facts supporting reasonable models vetted by those who study these things.

      A simple truth is all it is. If you don’t study computer programming, you can’t very well expect people to accept your opinions on what operating systems are best for programming hmmm?

      Science has allowed us to predict the movements of the universe, split the atom, go to the moon, send satellites to other planets in deep space, delve the very origins of time and space and has otherwise revolutionized the world and sewn it together with a digital communication network spanning the globe which requires a deep understanding and ability to calculate the relativity of time and space, and a thousands others things.

      I’ll take the word of people who can reliably do these things over a group that offer no sound analysis whatsoever, but merely attacks, innuendo and pseudo science backed by nothing.

      • First – let’s take a look at motivations. If I told a bunch of monkeys that they could secure billions of dollars in research grants if they studied how humans are turning the sky green (not even “whether” humans could affect the colour of the sky), you can bet I would get a “consensus” of monkeys screaming that the sky was turning green. The un-funded genious-types embarrassing the obcenely well-funded “climate scientists” with basic physics and statistics are civilizational heroes. It’s amazing what a group of smart people can do with truth on their side.

        Second – you’re right. It should just be science (but see point #1). When “climate scientists” massage, correct, adjust and homogenize their data beyond recognition then magically “lose” the original data set…something is wrong. Pure, raw data is the holy grail of science. Without it, there is no science as the conclusion cannot be reproduced by other researchers. …and it always seems that the massaging is in the same direction – roughly +.5 celcius from the mean over the past century. Hmmm.

        Third – it IS a matter of lay opinion. Read something. Not from the same sources. Form an intelligent opinion based on the latest research and not just from intellectually lazy journalists. This is one of the pivotal questions of our civilization – will the lay people sit back as the inbred little group of self-reinforcing climate scam artists push politicians to “rethink our institutions.”

  2. This guy might have taken a cross check to the head more than a few times. Somewhere in his house is a shrine to Al Gore

    • yes because scientists all over the world pray to politicians. With rhetoric like yours, why even question any observation?  Lets just let politicians like James Inhofe or companies like Exxon/GM tell us what’s good for us.  That worked out really well in the 60s/70s when Phillip Morris told us the science was unsettled with respect to a link between smoking and cancer

      • Those who worship politicians and see the world in terms of “tribes” naturally expect others to do the same.

        Those who live by emotion cannot understand those who live by logic.

        It is perhaps best if we ignore people who can only see this debate in those terms.

        They have nothing meaningful to offer clearly, and only distract from neccesary action.

  3. “Unfortunately, in the areas of science that have become politicized, there are those that exploit that culture of open debate by engaging in bad faith attacks. “

    Or alternatively, there are those who try to shut down their opposition by labeling them “climate deniers”, trying to have specific authors blackballed by journals, and accusing those who question them of “engaging in bad faith attacks”.

    One thing is certain:  when an area of science becomes politicized, one should not trust claims of “consensus”, nor should one rush to make widespread economic decisions based on said “consensus”.  One should certainly not rush to teach the “consensus” in elementary schools to naive children with no way to analyze the issue for themselves.  Rather, one should proceed with extreme caution and wait for the politicization to subside before forming policy, lest one find oneself drawing conclusions based on political pressure rather than scientific inquiry.

    • Except if one is gullible enough to accept the politicization as proof that the scientific inquiry into the matter is other than mostly settled.

      • Skeptics = gullible. Got it. Thanks for not “engaging in bad faith attacks”.

        Scientific inquiry is never “settled”, and never even “mostly settled” for issues that haven’t yet been subjected to the test of time and reproducibility. And again, especially when the issue is as fraught with emotion and political contrivance as this one seems to be.

        • Skeptics may or may not be gullible. However, gullible people, especially for heavily politicized issues, often think they’re skeptics.

          And yes.. it can be. Remember that settled does not mean immutable. It means understood as how things work. Newtonian physics was settled. Then Einstein came along. However this doesn’t mean Newton was completely wrong, and for most cases his theories work just fine, just there was more to it. We’re in about the same position with climate change and AGW. Sure we’ll probably find some permutations and additions to it as we go along, but the basic theories are sound and usable.

          • We are nowhere near the same position with AGW as we were with Newton. Good grief. Newtonian mechanics successfully met both the test of time and reproducibility, successfully predicting virtually every observable macroscopic motion except for some minor irregularities in Mercury’s orbit.

            AGW, on the other hand, has produced little besides entirely falsified predictions. It has also been around less than 30 years, having been preceded by the Global Cooling hysteria of the 70’s. It is entirely untested as far as reproducibility. I’m embarrassed for you that you even made the comparison.

          • And that’s the problem with getting your science from the media.
            Global Cooling was media driven, there was basically one article citing it. The scientific community, however, was already predicting global warming at that point.

            In short, try actually looking at the science, not just what you get from SDA and the inactivists.

          • “In short, try actually looking at the science, not just what you get from SDA and the inactivists.”

            You see? This is what hurts your cause. Skeptics are now “inactivists”. This transparent attempt at verbal bullying is characteristic of the AGW movement (and your posts) and immediately makes any decent scientist cringe.

            Science doesn’t proceed by belittling skeptics; it proceeds by encouraging skepticism because any good, falsifiable theory will either win people over on its merits or be disproven, and either way everyone wins. Insults and contempt are the hallmark of fads that are too weak to stand on their own, so their emotionally-attached supporters fear for their demise and try to pressure people into joining them. This does not inspire confidence in any objective observer.

            As for the science itself, the IPCC reports’ “best estimate” have consistently drastically over-estimated global warming over the past two decades. This is generally called being “falsified”. It’s not conclusive enough to reject AGW outright, but let’s cut the “settled” claim, shall we?

          • Science doesn’t proceed by wasting it’s time encouraging morons who can’t get off the couch to actually read the science.

          • You are making my case so well for me that I need not add anything further.

    • Scientists not only need to provide the facts but should also be saints?

      When they are repeatedly personally attacked by those who don’t even engage in science?

      Biting back at unfounded attacks being your measure? Really?

      Is that not a much higher standard than for those attacking their character while offering no facts?

      By setting a standard no human can reasonably be expected to achieve you essentially excuse these unethical tactics.

      It takes very little to sow confusion, as we’ve seen with various lobbies over the years and claiming a lack of consensus on this basis is foolish.

      “…so ignore them. They are blind guides leading the blind, and if one blind person guides another, they will both fall into a ditch…” ~ Matthew 15:14

      Preferring to not end up in the ditch, I think I’ll stick with those who have dedicated their lives to discovering the actual truth thank you very much.

      You get your financial advice from your butcher do you? LOL

      • (1) You seem to be laboring under the delusion that all scientists are in agreement on this issue. Not so. Try this, for example: link.
        If you’re going to argue from authority, there are arguments from pretty good authority in the other direction.

        (2) Even if all scientists were in agreement on AGW, it would still be suspicious if dissent were quelled with ridicule and silencing rather than by meeting it head on with arguments. It is noteworthy that AGW supporters routinely engage in such tactics. It is a sign of weakness.

        • Its almost laughable that you talk about good authority and then point to an op-ed defense piece as your proof. But I find your attacks old and stale. Yawn!

          • The op-ed was written by some of the greatest scientists in their fields, all of them greater than Dr. Mann.

          • And yet even they do not debate the properties of greenhouse gases or the CO2 rock-weathering thermostat.

            They merely point out that the predictive modelling is crap, which it is, and that to keep things in perspective, we probably still have a couple generations to get things together.

        • I’ve read most if not all the available scientific literature my friend. The disagreement you cite does not exist.

          You cannot find even one scientific paper discounting the Greenhous Gas effect, only arguments over progression and timing.

          By all means brother, find me one and I will agree.

          • There is no disagreement about the Greenhouse Gas effect, but there is considerable disagreement over the validity of models which predict significant warming due to anthropogenic contributions to it. The entire case for Global Warming rests on these.

            Read the letter I posted. You place more faith than I do in arguments from authority, so it should speak to you.

        • You’ve clearly failed to understand a word I’ve said given you just cited an article I agree with! LOL

          Read it again Gaunilon; the scientists who penned this article do not debate the properties of greenhouse gases or the models I’ve mentioned.

          What the article says is precisely what I’ve been saying: while the effect of greenhouse gases is well known, we cannot at this stage accurately predict the progression and timing of the warming.

          There is zero doubt that over the long term we need to ensure that we do not drive up CO2 to excessive levels. What are excessive levels? That’s a matter of opinion to some degree, but we can safely say that doubling them would be a very bad thing, ie around 800 to 1000 ppm.

          Climate change will have large effects on certain subsets of the population over the next century that we need to be prepared for, but frankly, reducing CO2 at this stage won’t prevent that at all. What’s already there is enough to shift climate considerably and we need to get on with making more straight-forward plans to help those people.

          In Canada the effects are more likely to be beneficial in than not over the next 50 years or so. Yes, you read that right. Except for the far north, but again, what’s done is done at this point.

          My primary concern is the run away effects of doing nothing for generations.

          While we need to act in this regard, the time frame is more forgiving than some will admit, that’s true, but if we don’t engage ourselves in advancing our technologies beyond fossil fuels now, then when?

  4. It’s surprising to see honest commentary in Macleans.  

  5. It’s the 21st century, and people are still trying to burn scientists at the stake.

    Bizarro world.

    • From a lot of your posts I get the sense that you view history as a mostly linear process of progress. The reality is that history is more cyclical than linear. Prior to the Industrial Revolution per capita economic growth – a reasonable measure of progress – was close to zero. For instance, it took Western Europe 1000 years to surpass the average level of wealth in Rome ca. 1 AD. We have great surges of development, followed by dark ages. Economic booms followed by depressions. Eras of liberalism followed by eras of conservatism. 

      • Up until about 1500CE China had the largest GDP in the world.  Then they hit a couple of bad emperors and went downhill while the west moved ahead.

        Now they are coming up again, and we’re going down.

        But liberalism and conservatism are recent western constructs, and are already obsolete.

      • And the parallel structure of your sentences there is telling.

  6. It’s amazing how people react emotionally to what is, from a scientific point of view, a pretty dull and uncontroversial field to study. It involves no new physical laws or theories, just laborious measurements and calculations using instruments and equations that are pretty routine. Apart from the fact that some people want the results to be different, the field is on the boring side for scientists, there are no great discoveries or innovations available in this field, and those who disagree with the results aren’t proposing any alternative physical laws to test.

  7. Old hide the decline Mike gets some softballs lobbed at him in this interview. We’re still trying to reproduce your “hockey stick” Mikey to no avail!

    • Really?  Someone is having trouble reproducing it?  That takes some doing, it’s just an average of a large number of independent thermometers.  It’s been reproduced countless times.  There have been different statistical approaches and data sets used by different authors, but the differences are invisible to the naked eye.

      • Good old Mikey, suppress the MWP so current increases look dramatically higher

        • time for you to leave your small community and get some university learning

          • Sorry got that, moved away from the big city to get away from the likes of you

        • From the article: ”
          The picture that emerged was this descent from the relatively warm period of the Medieval era, into the cold of the little Ice Age of the 17th to 19th centuries, followed by this dramatic warming of the past century”

          Odd way of suppressing it, right out in the open there.

        • I assume MWP=Medieval Warming Period, from ~950-125- AD.  The issue is whether it was warmer.  Using global data from tree rings, ice core sampling, coral reef records, sediment records, etc, Mann 2009 didn’t suppress anything;  the MWP was very warm in Southern Greenland, the North Atlantic, the Eurasian arctic, and parts of North America.  However Eurasia, some parts of North Am were much colder.  Summing up all the data from all over the world shows the MWP was warm, but not as hot as the planet is now.  That’s why it’s called GLOBAL warming, not Southern Greenland warming.  Before you criticize something (Mann’s work), it would be good to read it.

          • I see everybody is frothing up in defense of Mann. First, I do not deny humankind’s influence on climate, but am skeptical of the prognostications of the catastrophic nature of CO2. That said we are not seeing the catastrophic impacts as predicted by Mann , Hansen and company. Kindly correct me if I’m wrong, but meanwhile I’ll be going uptown on my e-bike to pick up some milk.

          • We can’t actually predict the progression and timing, so much more study is needed. Therefore, as far as “catastrophic” impacts I have to agree in part, since I don’t think they can actually claim that per se in the way many do.

            The real risks are for the world’s poor. Hundreds of million of people live in a subsistence state that is easily disrupted and could in fact lead to major disaster and death.

            The shifting climate zones, weather patterns, rising sea levels etc will have a massive impact on subsistence farming and water supplies, and constitutes in my opinion the single greatest danger over the next century.

          • Fair enough, but there are many other political and social issues that impact the worlds poorest people regardless of a changing climate man made or natural occurring. Do we have the capacity to cure all the problems of the world? Realistically, I think not. In the battle to help humanity, I do not believe the resources we are committing let alone what some would have us do are wisely spent on the CO2 bogeyman.

    • *cough* BEST *hack*. Also, Europe != the world; while Europe and eastern North America warmed, other parts of the world cooled during the MWP, and in yet others the changes were better described as “wet” and “dry” periods.

      Oh, and since you brought it up… what specifically did “hide the decline” refer to? I’m sure you know the details and context surrounding that specific phrase.

      • How terribly witty… looking at BEST results I guess I was trying to CURRY favour with others who state not so conclusive, like little warming

    • Mann’s 1999 hockey stick was chanllenged by McIntyre 2004, on the basis of disagreement over the statistical methods used (components analysis).  McIntyre produced their own graph, based solely on records from bristlecone pine proxies.  Wahl 2007 reanalyzed the the larger data set, with a variety of statistical methods, and confirmed Mann’s hockey stick.  Huang 2000 , using underground borehole proxies in North Am, Europe, Africa, and Australia, and again confirmed the hockey stick.  Smith 2006 used North Am stalagmite banding as a proxy, and came up with … a hockey stick!  Glacier records (Oerlemans 2005) show a hockey stick, tree rings show a hockey stick (Mann 2008).  Mann & Jones 2003, Esper et al 2002, Moberg et al 2005, Briffa et al 2001, Crowley & Lowrey 2000, Jones et al 1998… and the list goes on.  Climatologists draw upn a range of proxies, direct observatinos, and methodologies (statistical and otherwise) to calculate and graph temperature over time.  The Hockey stick is a fact, well proven, reproduceable.  To deny that shows either ignorance of the full body of the science, or a deep desire to not accept reality.

      • This is simply not true.  In fact, it is now widely accepted that the hockey stick graph is not only unsubstantiated, McIntyre reverse engineered the calculations (he was required to do so as Mann refused to release his methodology – which is directly contrary to basic scientific method which should invite attempts to disprove) and random numbers inserted into the equations produced a hockey stick graph.

        I will not bore readers here with the myriad of references which confirm this.  But what I will ask you to do is look at the number of times Dr. Rae quotes Mann, as confirming….Mann.    There’s purportedly thousands of scientists in agreement, but he needs to go to the same insular circle as support.

        I encourage readers to simply google “Mann’s hockey stick debunked” and you will get a plethora of sources, not from wackos as the smearmerchants here will have you believe, but from some of the most reputable scientists in the world.

  8. About 95% of C02 emissions are not manmade, but rather are natural and absorbed through natural processes. My understanding is that manmade C02 is still, however, problematic because it throws the system out of equilibrium. So fair enough, we should probably do something about it.

    But what I wonder is why reducing manmade C02 is the solution everybody jumps to. Why not find ways to increase the absorptive capacity of the earth? Why not find ways to reduce the production of natural C02? I’m okay with fighting climate change, it just seems to me that we are allocating resources in a pretty stupid fashion. If you had a deficit, would you restrict cuts to only 5% of your budget? Where is the kind of brilliant thinking, like that behind the iron hypothesis (putting iron in iron-deficient areas of the ocean spurs plankton blooms – the idea is not practical, but it is the kind of thing we should be looking for)?

    • “About 95% of C02 emissions are not manmade” is inaccurate.
      “My understanding is that manmade C02 is still, however, problematic “, glad to know.  Perhaps I can recommend a great Chemistry PhD you can chat with.  My old prof at the University of Toronto at Scarborough – James Thompson.  Give him a shout and he’ll explain it to you.

      “If you had a deficit, would you restrict cuts to only 5% of your budget?” Physical science does not follow the parameters of economics.  One of the first things you need to understand is the catalytic process in chemistry or even thresholds for that matter.

    • Probably because it’s easier to adjust CO2 intensive behavior than it is to adjust the physical properties of our planet — especially when you consider knock-on effects that most plans have.  Increasing plankton blooms, for instance, will have knock-on effects on species that survive on plankton, which will affect those species which compete with them, and so on.

      As difficult as it may be, adjusting our own behavior away from being CO2 intensive is probably the easiest and safest of the alternatives that are out there.  That said, I agree that we shouldn’t be taking any options off the table (such as nuclear).

      • Good luck with that.

  9. You amateur arm chair climatologists were the monks of the now defunct and sick doomsday religion of climate blame. Let us pray:
    ALGORE is my shepherd; I shall not think.
    He maketh me lie down in Greenzi pastures:
    He leadeth me beside the still-freezing waters.
    He selleth my soul for CO2:
    He leadeth me in the paths of self-righteousness for his own sake.
    Yea, though I walk through the valley of the shadow of reason,
    I will fear all logic: for thou art with me and thinking for me;
    Thy Gore’s family oil fortune and thy 10,000 square Gorey foot mansion, they comfort me.
    Thou preparest a movie in the presence of contradictory evidence:
    Thou anointest mine head with nonsense; my obedience runneth over.
    Surely blind faith and hysteria shall follow me all the days of my life:
    and I will dwell in the house of ALGORE forever.
    I see the change wasn’t science, it was superstation

    • umm, full marks for creativity.  Failing grade for reality

      • You are refering to Al Gore and his minions. right?

        • No I am referring to Inhofe, Koch, Mcleer and their minions

    • Come back credibility, come baaaaaaack!


    • So an ad hominem attack on a non-scientist is the best attempt at poisoning the well you can muster? Really? Man.. that’s just lazy. Pathetic and lazy.

  10. Unless or until someone in the “denier” group is prepared to offer an explanation as to why the standard model of particle physics would somehow be wrong regarding the LONG ESTABLISHED Green House Gas effect, in addition to being able to dispute the only existing model that explains why the earth has maintained liquid water on its surface for billions of years, i.e. the CO2 Rock-weathering Thermostat Model, then they don’t have a leg to stand on.
    The simple fact is that the CO2 Rock-weathering Thermostat Model is the only existing model for a reason. No one has even suggested another model because the evidence has become overwhelming in favour of the existing model. Talk to a paleo-geologist or paleo-climatologist if you want the skinny on that, or check out this lecture.
    The only area in which there is any debate is the predictive modeling. Over the short term it is very difficult to predict the progression and timing, because we don’t understand fully all the micro-level interactions.
    Over the long term however, there is little doubt that we are heating the planet, and that we may trigger some very startling tipping point effects. The fact that we can’t predict the progression gives us greater reason to be concerned, rather than the anti-evidence the “deniers” believe it to be.

    • Because,

      1 the model is rigged and
      2 they manipulated the data?

      • I see, so the entire basis of physics over the last century that has produced practically everything we didn’t have in the 19th century, is wrong. Because you say so. Alrighty then.

        Here, this one’s for you:

  11. Proof CO2 fears were exaggerated:” Science stands back and watches
    as the world walks away from CO2 mitigation and climate crisis belief.”

    Since nothing is worse than a climate crisis outside of a
    comet hit and since a little catastrophic climate crisis is impossible why are
    the millions of people involved in the global scientific community not acting
    like it’s the worst crisis imaginable? They have kids too that are doomed.

    That is %100 PROOF climate crisis from CO2 was exaggerated.

    Exaggeration trumps any scientific consensus.

    They gave us pesticides too don’t forget and real planet
    lovers need a better reason then a “they say” to look their kids in
    the eyes and condemn them to the greenhouse gas ovens.


    • If someone threatens to kill you and you don’t panic, obviously the threat is false.
      Really?  That’s the attempt at logic you’re going with?

      • musIims threaten our lives every day, do you see us panicing?

        • Replace Muslim with ‘Religion’ and you have a winner

        • Well, they don’t really, but if they did, you’d be right, that’s exactly my point.

    • You have a sadly twisted concept of “proof”.

      So let me get this straight, massive international conglomerates spend years engaging in attacks and mudding the waters, and the resulting confusion by the average person is then “proof” of a lack of “proof”?


      Honestly, if that’s the best you can come up with… LOL

  12. Every major premise of old Al’s movie has been debunked. The medieval warm period omitted from the famous hockey stick graph because it didn’t fit the narrative, the musk ox “scientist” who invented the drowning polar bear sob story for old Al’s movie has recently been suspended and is being investigated for scientific misconduct for making it up, the CERN atom smasher discovering that cosmic radiation released from the sun influences the climate, The IPCC’s politicized report on climate change being full of deliberate errors and outlandish horror scenarios more fitting of Hollywood B movie scripts than a scientific paper, and the list goes on.

    If you can sell a commodity that can’t be seen, touched, smelt or tasted, it’s going to breed corruption of the worst kind. Promoting AGW theory is now a big business with too much money tied up in it for the alarmists to just walk away and they are not going to let the facts get in the way of a good horror story and the obscene profits they will reap if they can keep the AGW fraud alive.

    • Again, from the article above: “The picture that emerged was this descent from the relatively warm period of the Medieval era, into the cold of the little Ice Age of the 17th to 19th centuries, followed by this dramatic warming of the past century”

      It just seems to me that directly including something is a very odd way to omit it.

    • “…medieval warm period omitted from the famous hockey stick graph…” yada yada yada.

      Can I include an eye roll here? LOL

      What I find interesting about the nonsense facts that deniers throw out is that no matter how often they are debunked, they still continue propogating the same garbage. Only a complete moron or someone trying to mislead others would still be repeating that old line. Sheesh.

      “…evidence suggests that the Medieval Warm Period was in fact warmer than today in many parts of the globe such as in the North Atlantic… However, evidence also suggests that some places were very much cooler than today including the tropical pacific. All in all, when the warm places are averaged out with the cool places, it becomes clear that the overall warmth was likely similar to early to mid 20th century warming.

      Since that early century warming, temperatures have risen well-beyond those achieved during the Medieval Warm Period across most of the Globe. This has been confirmed by the National Academy of Sciences Report on Climate Reconstructions. Further evidence (Figure 1) suggests that even in the Northern Hemisphere where the Medieval Warm Period was the most visible, temperatures are now beyond those experienced during Medieval times.

      Secondly, the Medieval Warm Period has known causes which explain both the scale of the warmth and the pattern. It has now become clear to scientists that the Medieval Warm Period occurred during a time which had higher than average solar radiation and less volcanic activity (both resulting in warming). New evidence is also suggesting that changes in ocean circulation patterns played a very important role in bringing warmer seawater into the North Atlantic. This explains much of the extraordinary warmth in that region. These causes of warming contrast significantly with today’s warming, which we know cannot be caused by the same mechanisms.

    • J Kirby, one of the CERN scientists said, “It actually says nothing about a possible cosmic-ray effect on clouds and climate, but it’s a very important first step.” 
      In order for cosmic rays to drive GW, 4 things need to happen: 1. the solar magnetic field must be getting stronger, 2. the number of cosmic rays reaching earth must be dropping, 3. cosmic rays must seed clouds, and 4. cloud cover on earth must be declining.  The CERN experiment only tested (a part of) #3.  So, like most individual scientific papers, it’s fascinating, but proves nothing. 
      Also, FWIW, (re 1) solar magnetic field is getting weaker, and has been for many years; overall in the last ~50 years, both Solar magnetics and cosmic ray bombardment of earth has been relatively unremarkable, we continue to go through cycles, ~10-15 years long.

  13. Speaking for the former climate change believer voting majority; it’s your theory doomers, you prove it.
    Climate science has done to science what abusive priests did for the Catholic Church.

    • Done and done.

      Unless you’re prepared to debunk both the standard model or particle physics and the CO2 rock-weathering thermostat model?


      Gee, big surprise.

      • We get it. We all need something or someone to believe in. You bow like a trained seal to authority and call yourself a liberal?

        • Belief is what we have before we have facts.

          You can believe with all your heart that the sky is brown, but factual observation corrects that erroneous belief. See how it works?

          And so I inform myself with facts, which so far you’ve avoided entirely.

          • Well then, belief is all you have then chicken little.

      • Done and none is more like it. The AGW hypothesis has been debunked, it fails in numerous ways to agree with the observable facts. The rest of your post is just noise.

        • None of which you seem capable of expressing apparently. I’m sure it makes you feel better to believe this of course, but you have nothing to back it with. Nothing at all in fact.

          Again, unless one is prepared to challenge the standard model of particle physics and the CO2 Rock-weathering thermostat model, the facts are that excess CO2 causes warming. Full Stop.

          The only thing in question is how much it will take, how long it will take and what the transitional period will look like precisely.

          But in no sense is there any doubt whatsoever that escalating CO2 will shift the climate.

  14. What kind of drugs do the deniers need to be on to dream up all of these “debunkings” they imagine?  Are their scientific sources the likes of Limbaugh, O’Reilly, and Beck (in which case I’ll go ahead and guess that oxycontin is the answer to my first question)?

    • Most unfortunately the drug in question is probably made by the brain itself:

      “…There is, of course, something deeply troubling about cognitive dissonance, since it suggests that we double-down on our beliefs in light of conflicting evidence.

      While neuroscientists have begun to decipher the anatomy of this mental flaw – you can blame your anterior cingulate cortex – I sometimes worry that the internet is making things worse.

      Although we’re all vulnerable to cognitive dissonance (and the paranoid style has always been a loud presence in American politics) we seem to squander ever more oxygen on worthless conversations about Obama’s birth certificate and the North American Union.

      After all, thanks to Google we can find “evidence” in support of practically any belief. If you can imagine the conspiracy theory, there is a website out there ardently promoting it, and a clan of fellow believers who share your peculiar obsession with fluoridated drinking water and the New World Order. The end result is that we never have to recant…”

      • Yes, the internet is a giant sewer of untreated information used as a learning tool or as support for entrenched bias.

        • Oh the irony! LOL

          You crack me up Mememine. How many times are you planning to double down precisely?

    • Proving once again climate change was the polticis of liberalism, not real science.

      • no u

  15. If any of you remaining believers still think catastrophic
    climate crisis is on its way for my kids and billions of other children, get
    your THE END IS NEAR sign and join the other END OF THE WORLD freaks.

    You don’t act like its’ crisis and we see right through you and
    the exaggerating scientists.

    • So, rather than look at the facts (that the world is warming, it’s our fault, and a warmer planet is a bad thing), mememine chooses to name-call and compare science (facts based on observable, reproducible observations, tested in a variety of ways) to religion (beliefs based on ancient texts).

      • cut and past much Mr Rae?

        • Yawn.

  16. Hypothesis is not theory and theory is not law. I thought scientists knew that. I know that politicians don’t. The only thing so far to come out of this is the progression of the debate from “Global Warming” to “Climate change”. Cool. Climate changes. Got it. Money well spent, and believe me on this, we’re talking trillions.

    • Hypotheses are individual empirically testable conjectures; while theories are collections of hypotheses that are logically linked together into a coherent explanation of some aspect of reality and which have individually or jointly received empirical support.
      For the record, the following are theories:
      Gravity [the Theory of Gravity]
      Germs [the Germ Theory of Disease]
      Earthquakes are caused by moving masses of land [Plate-Tectonic Theory]
      Photons [Einstein’s Quantum Theory of Light]
      Genetics [Mendel’s Theory of Inheritance]
      and so on and so forth.  Virtually all the data fits with the theory of Anthropogenic Climate Change, no better theory (ie one that better fits the data) has been proposed.  The decision to largely change the name to Climate Change, from talking to politicians and researchers, appears to have been to throw a bone to the deniers, who wanted it called CC.  IMHO, that was a bad move, because come people think changing the name of something changes what it is… like a “rose,” whose smell doesn’t change just because we’ve decided to call it a “snorpy.”

      • Nonsense. None of the data fits with the failed hypothesis of AWG. And no, the output from a model is not data. 

        You are either a liar or grossly ill informed. I will leave it up to you to figure out which classification fits you best Mr. Rae.

        • Don’t you have anything better to offer?

          Honestly, shouting “no!” isn’t a refutation of any sort.

          In fact it points out the weakness of your position.

  17. Another softball interview by a journalist who belongs to the climate cult. Clearly she knows one thing, her target market, given all the buffoons rallying in the comment section to support this junk science fraud Mann.

    • So, rather than look at the facts (that the world is warming, it’s our fault, and a warmer planet is a bad thing), physicsgrad chooses to name-call and declare massively replicated data to “junk science.”  How sad.  You remind me of someone who, at their graduation with a BAH, declared Easter Island to be a great mystery, as there was “no archeological evidence” to explain the heads.  Just because you don’t know something, doesn’t mean it’s not true.

      • Dr Dim, I have looked at all the facts, and no your claim that those facts are “the world is warming, it’s our fault, and a warmer planet is a bad thing” are not the facts at all but rather the result of junk science and a quasi religious belief.

        Just because you believe something, doesn’t mean it’s true. If you want a scientific debate this is not the place for it, and in any case science is not a debate and nor is it about a reaching a consensus as claimed by the green junk science brigade. Furthermore I doubt that you are qualified to participate in a discussion on the science. 

        • “I have looked at all the facts” Riiiight…

          Science is very much a debate. It’s based on evidence, which in many cases can be inconclusive – which is why people investigate. The first person to propose that salts ionize in water was initially ridiculed for his evidence and hypothesis.

  18. So here is a hypothesis, the planet was going into start of a small  ice age period due to volcanic activity but due to the industrial revolution it was stopped and possibley reversed. Now because of continue industrial activity the planet is warming up at a higher rate than ever before and causing climate change at an unprecedented rate never seen before. This unprecedented change is not natural and it can not be compared to anything in the past. How about population? The more people there that are living longer the more energy is needed to keep them warm in the winter. The fact that people move from the country to the city could be another factor. All these separate and independent factors could affect the warming of the planet. 

    • Population increase has been basically exponential since day one.  Your theory runs into trouble when it has to deal with how temperatures gradually cooled from the Medieval Warm Period until the industrial revolution — a period during which we were seeing a lot of population growth.

      Urbanization runs into problems in that rural areas with declining populations are also seeing increasing temperatures.

      Not that these couldn’t be additional factors that need to be figured in, but they really don’t account for the breadth and level of changes that we’re seeing.

  19. Was climate change an impending cataclysmic event or an exciting research opportunity?
    Q-How many climate change scientists does it take to change a light bulb?
    A-None, but they DO have full consensus that it WILL change.
    Almost all research money for climate change was into effects and almost never spent studying causes and so it wasn’t a question of honesty as to whether someone was lying or not, because they were studying the effects of a worst case scenario. The “crisis” was assumed. Would you say climate change isn’t real when you are paid to study the effects of climate change? Not only that but get this; all research money for studying effects was funded publicly and all research money into causal and denial climate change science was privately funded or more accurately, independently. Ice cores were the nails in climate change’s coffin because it turns out that there are too many ways to read them and it turns out that ice cores are not temperature dipsticks like in some Harry Potter movie. And nobody can explain the tropical fossils under the melting ice when this climate of today has never happened like this before. Dah!
    Here is further evidence that climate change science was a consultant’s wet dream and immune to the words “hoax” or “lie”;
    -It couldn’t be proven or disproven.
    -Every single scientist had his or hers personal definition of the effects of climate change.
    -There were millions of people in the global scientific community with doomed children as well and despite calling for catastrophic climate crisis, millions choose not to march to save their own children.
    -How is it that there were hundreds of thousands of consensus scientists and only a dozen climate change protesters?
    -These exploitive lab coat consultant’s we foolishly called saintly scientists for 26 years of needless CO2 panic, made environmentalism necessary in the first place with their pesticides that they denied for decades as being toxic.
    Climate change scientists have done to science what nasty priests did for the church.

  20. I enjoyed reading the article. I enjoyed reading the comments. It is interesting to see the viewpoints. I don’t understand why people that appear very able to articulate a position resort to insulting anyone who disagrees with that position. I was always taught that insulting the writer or speaker was a  sign that you were unable to win the debate hence decided to attack the individual instead. In any case this was enjoyable and if Macleans is around I will pop back in 2112 to see who is eating crow.

    • My kids are being fear mongered with a death by CO2. What better reason do we need to insult someone?

  21. comment moved

  22. Nonsense Mr Rae. None of the data fits with the failed hypothesis of AWG. And no, the output from a model is not data. 

    You are either a liar or grossly ill informed. I will leave it up to you to figure out which classification fits you best Mr. Rae.

  23. Anyone who complains of climate scientists spreading misinformation for their own monetary gain, and then parrots a few lines that they claim disproves the climate science, needs to consider that there is a lot MORE money to be made by climate change deniers who would be very happy to keep the status quo – and have fed them those parroted lines.

  24. I classify myself as neither skeptic nor a denier of global warming or climate change. I am in favour of climate change and a supporter of measures that it continue. Sure, it might be bad for people elsewhere, but I see nothing but good where I live. People are creative. They will figure out a way to stay alive where they are, or die trying.

  25. Read “The Hockey Stick Illusion” by Andrew Montford to get the true sense of the kind of man Mann is.   The scientific issues addressed in this book, let alone the deception by the Hockey Team, have not been rectified nor addressed in any serious manner.

  26. When you come out with an in-depth and understanding article framed around the work of Steve McIntyre and how it destroys Mr Mann’s math skills, or perhaps do a book review on Donna Laframboise’s latest effort, maybe I’ll think of buying your magazine again.

    Till then, let your sales die.

  27. Oh, please, Macleans!  Whatever happened to your journalistic ethics?!  Was it really necessary to act as unquestioning PR agent for this opus – which really should have been named, “Portrait of the Artist as an Aggrieved Mann: A Novel”.

    As others have noted, Andrew Montford’s “The Hockey Stick Illusion” and Donna Laframboise’s “The Delinquent Teenager Who Was Mistaken for the World’s Top Climate Expert” are far more deserving of your readers’ attention.

    There were several good reasons I chose not to renew my subscription when it expired last summer. This “interview” by Kate Lunau has provided me with yet another.