tag:blogger.com,1999:blog-9959776.post572995049581419517..comments2024-02-15T04:42:41.606+00:00Comments on James' Empty Blog: More on Schneider v Hegerl et alJames Annanhttp://www.blogger.com/profile/04318741813895533700noreply@blogger.comBlogger7125tag:blogger.com,1999:blog-9959776.post-60579222049478346932007-05-10T04:55:00.000+01:002007-05-10T04:55:00.000+01:00Yes, that looks right to me.However, I must correc...Yes, that looks right to me.<BR/><BR/>However, I must correct the "deliberate error" I made in my previous comment. Zero-width confidence intervals are not necessarily wrong. They are rather unconventional, perhaps, but that doesn't make them incorrect.James Annanhttps://www.blogger.com/profile/04318741813895533700noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-48865402330073034182007-05-09T14:09:00.000+01:002007-05-09T14:09:00.000+01:00One of the climateaudit readers has a very plausib...One of the climateaudit readers has a very plausible explanation of the error in the original Hegerl et al confidence interval calculations. See http://www.climateaudit.org/?p=1531#comment-108174Unknownhttps://www.blogger.com/profile/07966049624301704045noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-46713768022907237702007-05-03T20:29:00.000+01:002007-05-03T20:29:00.000+01:00Is that criticism by Steve McIntyre for all of cli...Is that criticism by Steve McIntyre for all of climate science, or just for temperature reconstructions?Heikohttps://www.blogger.com/profile/06839810379331430109noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-50174880996880950552007-05-03T17:55:00.000+01:002007-05-03T17:55:00.000+01:00It's very annoying that they won't say how they go...It's very annoying that they won't say how they got their results, but, as we know, this isn't the first such instance in this field.<BR/><BR/>This error in confidence interval estimation is not a "common error" outside of climate science. However, Eli, as you say, it has occurred on more than one occasion in recent climate science and it would be worthwhile pinning down exactly how the error is occurring.<BR/><BR/>In econometrics, people are obliged to archive working code in their articles so these silly sort of guessing games and trying to winkle details out of authors are unnecessary. This is merely one more unfortunate example of bad behavior in climate science - it shouldn't be up to me to be the only one to condemn this sort of stuff.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-9959776.post-88819081753700489972007-05-03T14:29:00.000+01:002007-05-03T14:29:00.000+01:00I think the same mistake was made by Huang Pollac...I think the same mistake was made by <A HREF="http://rabett.blogspot.com/2007/05/zero-crossing.html" REL="nofollow"> Huang Pollack and Shen</A>, and certainly shows in Monckton's version of their long term reconstruction. This appears to be a common error.EliRabetthttps://www.blogger.com/profile/07957002964638398767noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-65100553265068884062007-05-03T06:05:00.000+01:002007-05-03T06:05:00.000+01:00I'd be interested in your speculations.Well, my pr...<I>I'd be interested in your speculations.</I><BR/><BR/>Well, my primary interest is mainly in going from observational evidence (and physical theory as expressed in models) to predictions of future climate change, and not in the derivation and analysis of the observational evidence itself. So I haven't looked into the data in any great detail, and in fact I've never used any of the last 1000 years tree-ring stuff at all. However, there's a fair chance I will be moving in that direction over the next year or two (but it won't happen in a hurry).<BR/><BR/>Whether or not Hegerl et al underestimated the uncertainty at some points in their reconstruction might not have a huge effect on their final result for climate sensitivity, since uncertainty in the forcing and ocean heat uptake means there would be uncertainty in climate sensitivity even with a perfectly known temperature record. It's unclear how much difference would be made by adding uncertainty in the record (but it would be worth their checking: AIUI Schneider spent some time trying and failing to get this out of them). Of course in terms of the temperature reconstruction itself a zero width confidence interval is nonsense.James Annanhttps://www.blogger.com/profile/04318741813895533700noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-64131964413929854902007-05-03T01:03:00.000+01:002007-05-03T01:03:00.000+01:00"I won't speculate on what Hegerl et al actually d..."I won't speculate on what Hegerl et al actually did in their calculations."<BR/><BR/>I'd be interested in your speculations. I re-read their materials and it makes less sense than ever. Maybe it would be worth your inquiring, you're likely to have more luck in finding out than me. It would save much decoding if they would just provide code. Maybe a statistical reference as well.<BR/><BR/>BTW if you're trying to decode confidence intervals, have you tried figuring out how MBH99 confidence intervals are calculated? MBH98 is from calibration period residuals, but MBH99 is different. There's no statistical reference and it's another mystery. It's stumped a couple of statistics post-docs and me at climateaudit.Anonymousnoreply@blogger.com