How Did Hansen’s Super El Niño Prediction Do?
February 2nd, 2009Posted by: Roger Pielke, Jr.
I’ve always thought that predictions made should not be forgotten, but evaluated and learned from. About three years ago I made note of a prediction by NASA’s Jim Hansen that a “super El Niño” could be on the way. In Hansen’s words then:
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”, rivaling the 1983 and 1997-1998 El Ninos, which were successively labeled the “El Nino of the century” as they were of unprecedented strength in the previous 100 years.
How did this prediction do? Well there is a little something for everyone. There was in fact a 2006-2007 El Niño event. In the words of climatologist Mike McPhadden the event:
started late, ended early and was below average strength
So it wasn’t nearly a super El Niño, and by contrast, the tropical Pacific has been mostly in La Niña conditions since Hansen made his forecast. For his part, Hansen is still predicting the onset of an El Niño event that will drive global temperatures to a new record high in 2009 or 2010.
February 2nd, 2009 at 1:14 pm
Someday, El Nino must come. . .
I agree with you that it’s worth seeing how people predictions come out. Otherwise, the Jean Dixon Effect sets in. People get credit for the things that happened to be right and everyone forgets about all the wrong predictions.
Not to get repetitious, but someday, El Nino will come. If Hansen keeps predicting it, some day his prediction will happen to match the future.
February 2nd, 2009 at 10:09 pm
To be fair, though, Roger, isn’t it the case that the “prediction” was made in a draft paper circulated for comment, and that after receiving comment from of the ENSO community questioning the “Super El Nino” thing, he dropped it from the paper?
Isn’t the final version he submitted for publication a more reasonable assessment of what Hansen has and has not “predicted”, and should he not receive credit for listening to those who suggested he was wrong and changing his mind?
February 2nd, 2009 at 10:26 pm
[...] 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 [...]
February 3rd, 2009 at 3:06 am
Really Roger, this is not one of your better moments. What happened to the “fairness” you owed Hansen when you noted that that was a draft paper not intended for public distribution?
February 3rd, 2009 at 11:03 am
Thanks Coby, we could all learn from your approach to even-handed blogging, and especially your tone. FYI, I linked to your post in subsequent post.
February 3rd, 2009 at 1:19 pm
Thanks Roger. While I agree tone is important, especially for you when your goals are political point scoring, I’ve always thought content is the real indicator of integrity.
I’ll go read your post now but will likely not have time to discuss much til very late in the day.
February 6th, 2009 at 1:43 am
Roger, since you have helped us not to forget Hansen’s el Nino “prediction”, perhaps you could be so kind as to suggest: how we should (1) “evaluate and learn from” his prediction, (2) determine what “predictions made [are] not… forgotten”, (3) determine what the right time is to dredge them up and (4) make sure that we actually do so?
February 6th, 2009 at 1:49 am
TokyoTom-
Well, first, not everyone seems to agree whether or not Hansen withdrew the prediction after it was made.
I’m not sure what you are asking for. I co-edited a book on Prediction that addresses each of these questions in the context of the earth sciences, but maybe that is not what you are looking for?
February 6th, 2009 at 1:58 am
Roger, when you opened this with the statement “I’ve always thought that predictions made should not be forgotten, but evaluated and learned from,” I could hardly disagree, and looked forward to some lessons that you were troubling yourself to impart.
But I didn’t see any lessons, so I thought I could perhaps help by framing out what it looked, at first blush, that you were trying to accomplish.
Now I’m scratching my head.
February 6th, 2009 at 5:53 am
Tom-
In this case “forecast evaluation” refers to the _accuracy_ of the forecast. With that information in hand we could engage is a discussion of the forecast as a product and as part of a larger decision process. Evaluation of a deterministic forecast in the context of a probabilistic is not so straightforward. The role of the forecast in decision making also matters.
Both of these perspectives (product, process) are elaborated on in our book, Prediction.
However, as you have seen here (and I see elsewhere) any such conversation about forecast evaluation did not occur because people wished to discuss whether or not Hansen withdrew the forecast.
I will now make my own forecast — predictions made (or withdrawn) by Jim Hansen do not really lend themselves to constructive blog discussions;-)
If you are interested in such discussions, I recommend the threads offering a forecast evaluation of the five-year RMS hurricane damage outlook. For some reason, a better tone there;-)
February 7th, 2009 at 1:47 am
Roger, I took a look back at your earlier note about Hansen`s “prediction”*
“If he is proven right with this forecast, contrary to all of the models and statistics, then his credibility will rise far beyond its already stratospheric levels. If he is wrong, he will be brought a bit back to Earth by his critics who will use this against him.”
Does this, and the lack of any other discussion of “lessons” help to explain your purposes? Trying to help Hansen to be more cautious?
February 7th, 2009 at 2:33 am
Tom-
Well, probably not Hansen, as I expect he has better things to do than read this blog. But caution in the issuance of forecasts is certainly a lesson that many could learn from experience, and something I have written about at length.
Compare Mickey Glantz writing of Hansen’s forecast:
“The year 2006 was forecast by some well-known and influential scientists to be the year of a “Super El Niño,” a label never before used. It did not happen. Who really cares? If a super event had taken place, those forecasters would have been heroes. But it didn’t. They go along making forecasts, as if there had been no cost associated with bad forecasts. Yet, for each forecast that is issued, people are listening and taking action based on it.”
http://www.fragilecologies.com/feb05_07.html
April 5th, 2009 at 10:41 am
[...] Hansen’s prediction of a “super” event “rivaling the 1983 and 1997-1998 El Niños” never came true. Undeterred, Hansen is still predicting the onset of an El Niño event that will drive global temperatures to a new record high in 2009 or 2010. (h/t to Roger Pielke Jr on Prometheus) [...]
April 5th, 2009 at 3:47 pm
See for a comparison of 1972-1983 with 1998-2009 using the NINO34 index:
http://home.casema.nl/errenwijlens/co2/ninoforecast.gif
They compare very well just up to 2007. 2009 failed miserably, perhaps there is another occasion for a “super El Nino” in 2023…