On Hansen on El Niño (sub. req.)
John, your ABQ Journal story reads: “Hansen’s prediction is at odds with a forecast issued Thursday by the federal government’s Climate Prediction Center, which noted significant uncertainty in the computer climate models used to forecast what will happen next winter. None of the 20 models surveyed by federal forecasters are predicting as strong an El Niño as Hansen suggests.”
From the CPC forecast: “Most of the statistical and coupled model forecasts indicate ENSO-neutral conditions in the tropical Pacific through the end of 2006 (Fig. 6). The spread of the most recent statistical and coupled model forecasts (weak La Niña to weak El Niño) indicates uncertainty in the outlooks for the last half of the year. However, current conditions (stronger-than-average easterly winds over the central equatorial Pacific and below-average upper-ocean heat content) support those forecasts indicating that La Nina conditions will continue for the next 1-3 months.”
This doesn’t seem to be much of a conflict, if any.
Forecast: “ENSO-neutral conditions in the tropical Pacific through the end of 2006”
Hansen: “We suggest that an El Nino is likely to originate in 2006 and that there is a good chance it will be a ‘super El Nino.'”
El Ninos, including the two to which Hansen draws explicit comparisons, rise in the fall. Super El Ninos – the ones he’s talking about, rise significantly in the fall, with greatest strength in mid winter.* I’m puzzled as to how you would argue that there is no conflict between a forecast of El Nino starting this year, quite possibly a strong one and a forecast that at its weakest says there is nothing that can usefully be said about the coming winter, and at its strongest points to models suggesting no El Nino.
If Bloom can’t see the difference between a neutral ENSO forecast and a “Super El Nino” then he’s already worried.
Interestingly the late Theodore Landscheidt in 2003 also predicted an El Nino for later this year:
As the date 2007.2 is closer to 2006/2007 than to 2007/2008 it is to be expected that El Niño will already emerge around July 2006 and last at least till May 2007 (Probability 80 %)
I don’t think Steve Bloom will be giving him any credit since it was all calculated on the basis of solar variation and orbital cycles based on KAM theory.
John A. is right that I don’t tend to give denialist crackpots a lot of credit.
John F., maybe I’m splitting hairs here, but the part about “uncertainty in the outlooks for the rest of the year” struck me as very weak. Note that Hansen said (in effect) that the theory and models are missing something (i.e., the significance of a warm West Pacific combined with a substantial East Pacific warm anomaly already formed in February of this year). I think it’s reasonable to say that ENSO models are considered on the weak side (fair enough since arguably this is more a matter of weather prediction than climate prediction), and of course Hansen can be said to know a little something about models. I think your story noted that he is considered a leading U.S. climate scientist, which perhaps slightly undersells his status, but in terms of his role in modelling a phrase along the lines of “leading the international field for the last thirty years” might not have been inappropiate. Regarding Mark Cane, noting that Hansen prominently features a private communication with him, it would be interesting to know exactly what the difference is between them. Absent something specific from Cane, I suspect there’s more than a little professional jealousy involved here.
Steve B –
On the “uncertainty in the outlooks for the rest of the year,” you’re not splitting hairs. You’re missing the point. The consensus view – what I call “the bulk of the science”, which I alluded to in my story by quoting the CPC forecast – says current conditions do not support a confident forecast. The experts in the field are looking at the same data and not seeing the same thing Hansen and his colleagues are.
My job is to explain to readers what the bulk of the science says on a question like this, which I’ve done. The point is not to argue who’s right, but to give the newspaper’s readers the clearest possible picture of the mainstream view. Hansen’s stature is the reason I did the story, but it would have been irresponsible not to explain to readers that he’s out of the mainstream here.
If Hansen turns out to be right, and the bulk of the science shifts in his direction, I’ll happily write that story (sorry Aussie readers, we need the rain).
A question: Given your reliance on mainstream scientific thinking on climate change, I’m puzzled about what seems to be a williness to embrace something well outside the mainstream in this case. How do you think one should decide when to accept mainstream science and when to embrace the outlier, as you seem to want to do in this case?
John, I did spend a couple of hours looking at all of this before I commented. While that’s not exactly a comprehensive overview, it was enough to convince me that there’s something to the mechanism Hansen proposes (one which is not presently taken into account in the theory or models, as he notes).
There is some very interesting science politics going on here. Note that something similar happened in the last year with respect to ice sheet collapse, but in that case Richard Alley was happy to step back somewhat and let Hansen take the lead on the new paradigm. Mark Cape was obviously a little less happy about doing the same. BTW, it would have been nice to have a little more detail from him than “Hansen is mostly wrong,” but I do understand the limitations of the medium. Just out of curiosity, was he clear about whether he was referring to the next El Nino happening soon or the prediction of GW strengthening? From the context, it seems it must be the latter. On the former, is it possible that Cape had planned his own announcement on this and/or is PO’d about being “scooped” or not being listed as a co-author (noting that Hansen’s verbatim quote of him is a little unusual in a paper)? Did you ask him about the significance of the East Pacific warm anomaly?
Regarding the CPC projection (the consensus), didn’t the language used strike you as exceptionally uncertain? I interpret that sort of language as the models being very weak, so diverging from them becomes corrspondingly a less bold move. While the unreliability of the models does not in and of itself make Hansen more likely to be right, it definitely makes sidestepping them seem more reasonable.
Finally, it’s important to distinguish between the two predictions. One of them (the East Pacific warm anomaly as a precursor for a strong EL Nino) is very much short term, and we’ll see what happens. The other much more important prediction (of El Ninos enhanced by GW) won’t be completely resolved by the next El Nino or even the one after, so it’s important to distinguish between the two.
To answer your question more directly, I was extremely impressed by Hansen’s correct prediction of 2005 global temperature. Adding this to his correct predictions about overall warming and the extent of Pinatubo cooling counts for a lot IMHO. Hansen’s reputation, scientific and public, is to a great extent a result of his having made these successful predictions in the past. As well, there’s the consideration that the natural conservatism of most scientists makes them hesitant to make such predictions in any kind of public forum until they are very firm indeed. Hansen is obviously doing things a bit differently, but I think the times demand it. So, as with the the hurricane stuff from the last year, Hansen’s ENSO predictions may just be an early statement of a new consensus.
All of that said, I wonder to what extent it’s significant that Hansen did not release the draft paper to the public, but instead circulated it to colleagues for their comments prior to submitting it to BAMS. Was it kosher for RP Jr. to have made it public? I know it was in a web location that is technically accessible to the public, but it’s doubtful that anyone would have known to look there without first being told there was something to see. Also, by soliciting comments in the way he did, Hansen was making it clear that changes to the paper are very much a possibility. Given this, your story could be rendered retrospectively premature, to coin a phrase.
I have to go with what John F sez, SB.
But I’d like Johnny A. to mention the last couplea TL forecasts and discuss whether they verified.
I don’t really care about the politics. I care about trying to tell folks in Albuquerque what can and can’t be said about next winter’s forecast.
It doesn’t really matter whether Steve Bloom or John Fleck thinks there’s something to Hansen’s forecast. (And obviously I must have thought there was some credibility to it, or I wouldn’t have written a story.) But what matters more is what experts in the field think. If Hansen’s argument wins converts, then the mainstream shifts his way. Until then, it’s outside of the mainstream and must be treated as such.
You continue to misunderstand the importance of the CPC forecast. They’re not saying “don’t know.” They’re saying “can’t know.” The measured uncertainty is reflective of the mainstream view: that ENSO, especially now (they frequently call spring a “predictability barrier”), is not forecastable on this time scale. Hence, in making the forecast he did, Hansen is outside the mainstream. (And the forecasts in the CPC spaghetti plot include “empirical models”, which use past conditions rather than dynamical calculations to forecast – exactly the technique Hansen is using. They’ve all seen the same data as Hansen and come to different conclusions.)
Cane was clear that he disagreed with both the AGW argument and the 2006-07 forecast. He’s published at length on the key questions.
I can’t comment on your final paragraph, except to say that I’m not in the business of self-censoring once I’ve got information that I think is useful or relevant or important.
Fair enough, John, except that in the case of the ENSO models I’d just say it’s hard to distinguish between “can’t know” and “models not good enough to know.” I’m clearly willing to give Hnasen a little more credit on this than you are, but if I were a journalist I’d probably approach it more conservatively. That said, nobody should read too much into this since Hansen did only say “likely.”
My last paragraph was aimed more at RP Jr. than you. We’ll see if he stays on Hansen’s mailing list after this episode.
Maybe you can do a follow-up when the paper is published.
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