What Did Hansen Predict, and When Did He Predict It?

Roger Pielke Jr. has a bit of an odd post up today taking James Hansen to task for predicting a “super El Niño” in 2006, which did not come to pass. Here’s Roger:

I’ve always thought that predictions made should not be forgotten, but evaluated and learned from.

The “prediction” in question, which I wrote about (somewhat critically) at the time, came in a draft paper Hansen circulated for comment. The “prediction” deserved criticism at the time. But to his credit, Hansen, at the time, before the paper was published, backed off, after hearing from members of the ENSO community who convinced him that the prediction was problematic. In the final version of the paper, published a few months later in PNAS, the forecast of a “super El Nino” in 2006 is gone.

There’s a significant difference between ideas shared in a draft circulated for comment and those finally published. To cite the former and ignore the latter in this case seems a bit misleading.

[update: Coby Beck has more details about the chain of events back in 2006 that I’d forgotten.]


  1. If your knowledge of pre- versus post-publication versions is correct, then this is a good post. Surely the change in emphasis becomes an example of the peer-review process working as intended?

    Discouraging early review, by subsequently treating the early version as definitive or accountable results, is discouraging open science research. Bring on the bad old days.

  2. Hi John-

    So if a scientist makes a prediction outside of the peer review process that prediction doesn’t exist? Interesting theory.

    In follow up email he clarified that his prediction was probabilistic, not categorical, but I did not see him as backing off the prediction one bit, as you suggest he did:

    “Global warming has increased the east-west equatorial temperature gradient and that should increase the probability of a super El Nino. It is still a crap shoot, so it requires many rolls of the dice for empirical verification. Even in the last 30 years there have been only two super El Ninos.”


    Hansen routinely puts out emails and posts commentaries on his website for broad dissemination, so should we ignore all that and only look at his peer reviewed work?

    His prediction did not survive peer review you are right but that does not mean that he did not make it.

  3. So if a scientist makes a prediction outside of the peer review process that prediction doesn’t exist? Interesting theory. LOL

    Jeff, we’re waiting and while we’re waiting could you please tell us what you thought about Hansen’s suggestion that skeptics ought to be jailed.

    Do you think Roger should be jailed, Jeff?

  4. Roger –

    This incident is of some importance to me because, at the time, I wrote a newspaper story based on the original draft that Hansen was circulating for comment. The fact that it was merely in the discussion phase and subject to revision based on input from Hansen’s colleagues should have given me pause, but it didn’t. I view that now as a mistake, because when the final paper came out several months later, the “prediction” on which my newspaper story was based had been removed. In fact, I’d forgotten the middle step, but your blog post shows that Hansen himself had dropped the “prediction” within a fortnight.

    There is a discussion of a general probability of more “super El Ninos” in the PNAS paper, but the specific 2006 “prediction” is gone. In other words, at the time the “prediction” was retracted, by Hansen himself. It’s not that it didn’t exist. It’s that Hansen himself apparently concluded it was in some way wrong.

    I view writing that story as a journalistic mistake – viewing a provisional idea being discussed by Hansen and his colleagues as a “prediction”, subject at the time to revision, as a “prediction”. So for my purposes, yes, I believe there is a difference.

    And if I was writing journalism about this (which this blog is not, nor is yours), I’d feel compelled to discuss the full context, noting that Hansen removed his “prediction” himself from the next draft, which he circulated less than two weeks later. That seems a relevant fact.

  5. So there is absolutely no interest by you as a journalist to question why Hansen first made the prediction and why it was removed some time later.

    Secondly Jeff, could you hold you hand to your heart and say with all sincerity you would offer the same leeway to some that doesn’t subscribe to your catastrophist view on climate change?

    Now I sitting down comfortably in my chair so please don’t make me fall off.

    Lastly, Roger is not a journalist and his blog is not a newspaper or weren’t you aware of that.

  6. Jeff,

    Your position would have merit if Hansen’s prediction was a one time error. It is not.

    As you can see at: http://data.giss.nasa.gov/gistemp/2008/:

    “Given our expectation of the next El Niño beginning in 2009 or 2010, it still seems likely that a new global temperature record will be set within the next 1-2 years”

    Hansen is still making these predictions. This may not be a peer reviewed publication, but it is a US Government website, the contents of which have already impacted climate policy discourse.

    As long as Hansen makes these non-peer reviewed predictions, his past predictive performance is of considerable relevance.

  7. John-

    Hansen’s “prediction” was covered by the AP and other media outlets in which Hansen was quoted directly. Hansen reiterated it on his public list. I am unaware of any statement he made retracting the prediction or the comments made via his public list, though I am happy to be pointed to such statements, if they exist.

    I can understand why you feel that your article was a mistake (had you gotten Hansen on the record at the time, I don’t think it would have been).

    I have just put up a post where I say that you are correct that I should have noted that Hansen’s prediction did not survive peer review.

    If criticizing my look back helps you to feel that you have rectified your original error in some sort of global karma sense, then I guess I am just playing my part 😉

  8. Roger –

    I’d love a citation on the other media that covered this. I don’t remember anyone other than me covering it at the time, and a quick LexisNexis search just turned up blank.

  9. “So if a scientist makes a prediction outside of the peer review process that prediction doesn’t exist? Interesting theory.”

    So if a scientist changes his prediction it should not be noted? Interesting ethic.

  10. Roger –


    The first one (geotimes) is not a super El Nino forecast. It’s from earlier in the year, and if you go back to the original source, Hansen et al. are saying that *if* an El Nino happens (which they suggest is likely), the result will be a warm planet. No super El Nino forecast there.

    The second looks like a blog rewrite of the various stuff you and I were writing about at the time. No quotes from Hansen, or suggestion that the author did anything other than crib from the work of others.

    The third is what looks like something pulled by the Las Cruces Sun-News from the AP rewrite of my original story.

    The fourth has a throwaway line at the end about El Nino that seems to be a reference from the final PNAS paper, but offers no mention of a “super El Nino” prediction.

    This is all pretty consistent with my memory.

  11. Eli –

    Apparently, yes. “Jeff” is the character I send out to defend Hansen and criticize Roger, that I might avoid doing it myself. I’m not sure, but I think that’s “Jeff” in the background of my blog picture at the Easy-Do Parties Lady’s house. He’s drinking heavily.

  12. Jeff, thanks for RTFR, I googled “Super el Nino” Hansen and the earliest reference was Roger (you apparently found it from him, both were 4/6).

    That essentially puts Roger in the position of pleading for mercy as an orphan after killing mom and data

    (yes, I know, but it came out that way)

  13. John/Jeff-

    Are we reading the same things?

    “As for what temperatures the future might hold, Hansen and colleagues wrote that impending El Niño conditions for 2006 and 2007 will boost global temperatures such that the “record will almost surely be broken.”

    Lots of use of “will” there.

  14. Roger –

    Useful to go back to the original for the full context of what Hansen et al wrote:


    “The quasi-regularity of recent El Niños at intervals of about 4 years (there was a weak El Niño in 2002) suggests the likelihood of an El Niño in 2006 or at latest 2007. In such a case the 2005 global temperature record will almost surely be broken.”

    He’s simply forecasting another El Nino in the next few years based on recurrence intervals, not forecasting a “super El Nino”. It might be worth exploring in the context of holding Hansen accountable for his “predictions”, but it’s not a “super El Nino” prediction.

  15. Hi John-

    We can certainly agree to disagree on this one.

    Hansen was clearly predicting an El Nino event. He also at the same time was predicting an increased likelihood of strong El Ninos, e.g.,

    “Hansen and his colleagues suggest that the increased temperature difference between the Western and Eastern Pacific may boost the likelihood of strong El Ninos, such as those of 1983 and 1998. ”

    I think it is pretty clear that he was anticipating a super El Nino, and said as much in his draft paper and then in an follow up email to his list. When the paper finally appeared that specific prediction was toned down, but I did not view that as a withdrawal of the prediction — it just didn’t survive peer review.

    I think we can agree that if he did make the forecast, it was not a good one 😉

  16. @Roger

    And? . Fact: there is no paper, no interview, no press release.Only a preprint. So, where is the interview with the press or the big paper with the prediction? You haven’t shown yet. I am waiting.

    The example is rather good to show how science does work. Somebody has an idea and colleagues criticize and support the idea. The idea is improved or canceled or postponed. What is wrong with that? What is your idea about science? Lying and try to embarrass other researchers? Sorry, I do not understand your motivation.

  17. The idea is improved or canceled or postponed. What is wrong with that? What is your idea about science? Lying and try to embarrass other researchers? Sorry, I do not understand your motivation.

    The motivation, in my view, is to criticize/make embarrassing open scientific discussion.

    Whether for personal gain on RP Jr’s part or what is unknown.

    And the comical assertion that Hansen’s suggestion that skeptics ought to be jailed just puts the entire thing into perspective, doesn’t it? Demonization of an idol or totem.



  18. Wait a second.

    Dano is defending open scientific discussion? I just read him at Deltoid crowing about his role in getting the Pielkes to shut down their blog comments due to his constant abuse and trolling. Nice work Dano.

    Demonization of an idol or totem indeed.

  19. bouldersolar,

    you are full of s—. Why do you have to make s— up to have an argument? Is it because you have nothing else? Awww.



  20. Jeff

    Answer Roger’s freaking question. Do you think a scientist shouldn’t make a prediction unless it’s peer reviewed?

    Do you?

  21. Dano –

    Please don’t go away. I’ve missed you! Don’t I write enough about bicycling any more?

    LG – I’m comfortable that Roger and I have fully aired our disagreements, and responded to one another’s questions, and understand one another’s views. I have found it a useful discussion. But I can’t speak for “Jeff”.

  22. In sort of reverse chronological order

    More bicycling, more birds and Eli might hang around here.

    LG, get thee to a science seminar or conference. Believe Eli, scientists don’t take oaths of silence, as for engineers….WHOO.

    Actually. . . but that’s another story.

  23. go to a science conference? Why I thought the sceince was settled, Eli. Then I would have to listen to people like you.

    JF, sorry I thought I read your first name was Jeff.

    You think you may have settled differences, however you still need to answer the question.

  24. Coby

    Stop the lying, he’s on tape saying as much, you dishonest creep.

    he basically said he’d like to see executives like Exxon’s dumped in prison for crimes against humanity.

    Personally, id like to see dishonest truth benders like you thrown in there.

    Fess up and stop hiding behind dishinesty.

  25. Pingback: jfleck at inkstain » Ah, Internet Discourse

  26. The constipated trolls are using the strategy: “my aggressive consternation done prrrrooooves! there ain’t no globul warmin’ “.


    Mr Fleck:

    I mostly lurk here these days, I haven’t gone away.



    The Pielkes limiting comments on their site (due to Eli and Dano and others pointing out the flaws in their arguments) limits discussion, despite your widdle wishy-wish for it to be the opposite.



  27. All-

    Just to correct the record:.

    We’ve never limited comments on Prometheus.

    You are all welcome to participate. We just ask for some common courtesy among commenters, which our site (mostly) has.

    Critical comments always welcomed. The choice to participate in our discussions is yours.

  28. Colby

    Do a google seach on PBS/ Hansen. the last 5 minutes is where he’s asked the question and sure enough Jimmy wants them jailed for crimes against his research, er, I meant crimes against humanity.

    Jimmy Hansen now regards crimes against his research as a crime against humanity.. lol.

    Shouldn’t be too hard for a beagle like fact finder like you, or is it.

    When you’ve found it I would be good if you updated the record on your blog as we don’t want people getting the wrong idea, right?

  29. Just for the record, Roger Sr., before you canned your comment section you used to get a fair number of opposing views from climate scientists.

    I remember those days well — you with your head down, the effect of innumerable minor wounds beginning to take their toll, pawing the ground in preparation for yet another fruitless charge despite your labored breathing and blurring vision… across the arena Gavin, William and James in their brightly-sequined costumes, fully enjoying the contest but with slight smiles indicating their knowledge of the inevitable conclusion… the salty taste of popcorn in my mouth…

    Where was I? Oh yes: Now you get no opposing views, I assume not because you censor but because you don’t get submissions. Why would that be?

  30. this type of filter permits more constructive science debates.

    Ah, yes. The “conflation of everything into science” tack. Well, the wind isn’t blowing this way, as the question isn’t about a scientific finding, it’s about whether RP Sr’s son is trolling for pub.

    Oh, and the last time I tried at RP Sr’s place, he avoided my trying to nail him down about his implicit assertion that glaciers are not in retreat across the planet. Of course that’s hokum, but now you can’t call RP Sr on it because you can’t comment there.



  31. Dano, to get some of Roger’s liver/goat at Prometheus, you need to register there by providing a username and email address. You’ll receive a login password that you can reset.

  32. Feb. 5, 2009 (Reuters) – The La Nina weather anomaly will persist into the spring of 2009 but should gradually weaken during that period, the U.S. Climate Prediction Center said on Thursday.

    In a monthly update, the CPC said “a majority of the model forecasts … indicate a gradual weakening of La Nina through February-April 2009, with an eventual transition to neutral conditions.”
    And after neutral, by, oh, 2009 or 2010, well, we’ll see.

  33. Regarding Pielke Sr’s putative evasion of the Glacier Question, there’s nothing to evade & he undoubtedly had better ways to spend his time than responding to non-issues: a) Glaciers world-wide have been in retreat, more or less, since they, um, started their current retreat, and b), since less than 10% of glaciers have actually been surveyed, no one can really say what the current mean rate of retreat is; but better they should be retreating than advancing, as that would probably signal the onset of the next (and by now, overdue) round of serious glaciation (oh, but wait; now I get it: Dano, with his Olympian insight into our planet’s long history, realizes what so few others do: That without greedy, profligate humans mucking with its oh-so-delicately balanced metasystems, glaciers would be perfectly static, with yearly deposits and withdrawals in perfect, serene balance (former mega-glacial episodes were of course the result of human interference)).

  34. I suspect that the real reason Pielke Sr. closed the comments section of his blog was weariness of the unending and cluelessly inane comments from the Bloomster.

    And now it appears he’s taken a Creative Writing course. Ye Gods, what next – Nattering Nabobs of Negativity?

  35. The Saffire/Agnew shtick is more up your alley, PaddikJ.

    On the science, you’re completely confused. Recalling the parable of the therapists and the lightbulb, I won’t try to change you.

  36. Pingback: jfleck at inkstain » Annan On the Pielke-Hansen Kerfuffle

  37. PaddikJoke:

    RP Sr’s implicit assertion was that glaciers were not retreating. We know that is not true, and I tried to nail him down on what evidence he was basing his evidenceless assertion.

    Now, when “warmers” do this, it is “not scientific discussion”. When RP Sr does this, the spam trolls harrumph in umbrage at my asking for clarification.

    Is it any wonder denialists are ridiculed as a joke?



  38. Dano, kiddo, love the way you always separate the wheat from the chaff.

    Denialists would not be satisfied with the data even if 99.999% of glaciers were measured. There is always something that keeps them from rational thought processes.

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