Comments on: My Erice Presentation http://climateaudit.org/2008/09/16/my-erice-presentation/ by Steve McIntyre Tue, 18 Jun 2013 04:29:58 +0000 hourly 1 http://wordpress.com/ By: Pat Frank http://climateaudit.org/2008/09/16/my-erice-presentation/#comment-162236 Thu, 18 Sep 2008 22:07:15 +0000 http://www.climateaudit.org/?p=3651#comment-162236 Steve, the Erice manuscript, at least the one I downloaded, needs a serious proofing. Will you do it, or would you like a volunteer?

]]> By: Jeff Id http://climateaudit.org/2008/09/16/my-erice-presentation/#comment-162235 Wed, 17 Sep 2008 23:44:34 +0000 http://www.climateaudit.org/?p=3651#comment-162235 Bender #34,

I know. If you look at what I found in the data modifications, a forecast extrapolated spike was added to the recent end of the Mann08 proxies. From what I can tell, (still a rookie) it is a nice way to correct for “divergence”. I probably wasn’t clear enough.

This was done despite the availability of better, newer data in at least one case. (our host’s point in #21)

This is why Steve McIntyre was looking at the software to see if it really was used in the correlation calcs.

If the theory doesn’t fit the data, change the data.
If the darn trees won’t grow, we’ll grow em with statistical fertilizer. BS has more than one use. (I couldn’t resist)

]]> By: per http://climateaudit.org/2008/09/16/my-erice-presentation/#comment-162234 Wed, 17 Sep 2008 22:08:45 +0000 http://www.climateaudit.org/?p=3651#comment-162234 hi
the ERICE documentation is more like a paper, than the presentation. Have I got this wrong, and will Steve be putting the presentation (ppt ?) up ?

I think that most scientists are quite horrified by some of the behaviour unearthed in the course of this fiasco. That is why it is very good to see Steve having the standing to be able to present (credibly) to other scientists.

I do think that there is one very important difference practically in how science works. In business, there is often a legal obligation to provide information; so it doesn’t matter how rude you are, it has to be given to you. In science, there is no statutory obligation, and it goes on people’s good will. In these circumstances, if you are abrasive, people will occasionally refuse you just for personal reasons. None of this is exculpatory; just a comment.

per

]]> By: bender http://climateaudit.org/2008/09/16/my-erice-presentation/#comment-162233 Wed, 17 Sep 2008 21:53:29 +0000 http://www.climateaudit.org/?p=3651#comment-162233 Re: Jeff Id (#33), The “divergence problem” is a real and well-known problem in dendroclimatology. An area of active research.

]]> By: Jeff Id http://climateaudit.org/2008/09/16/my-erice-presentation/#comment-162232 Wed, 17 Sep 2008 20:38:20 +0000 http://www.climateaudit.org/?p=3651#comment-162232 I can understand the use of an algorithm like this to “fill in” data between knowns. It probably would do an ok job, but prediction is unreasonable. I think it shows from the strong net positive in the (primarily tree ring) signal I graphed whereas the same tree rings are experiencing “divergence” in reality.

I love that word divergence.

The grid cell thing I read about in Mann08 makes more sense to me than extension. Its accuracy would depend on the density and proximity of real values. While its accuracy might be off, at least it makes sense.

]]> By: Craig Loehle http://climateaudit.org/2008/09/16/my-erice-presentation/#comment-162231 Wed, 17 Sep 2008 20:34:40 +0000 http://www.climateaudit.org/?p=3651#comment-162231 The key proxy values for the most recent years are extrapolated…wow. Is this like projected earnings for a company? Of course, you don’t get to base a proof of something on projected earnings…

]]> By: bender http://climateaudit.org/2008/09/16/my-erice-presentation/#comment-162230 Wed, 17 Sep 2008 20:14:50 +0000 http://www.climateaudit.org/?p=3651#comment-162230 Re: Steve McIntyre (#30),
Quite so.

]]> By: Steve McIntyre http://climateaudit.org/2008/09/16/my-erice-presentation/#comment-162229 Wed, 17 Sep 2008 20:08:30 +0000 http://www.climateaudit.org/?p=3651#comment-162229 It’s also a method used originally to interpolate like data e.g. missing gridcell values in a gridcell network. Not exactly the same thing as going from bristlecones and disturbed Finnish sediments to instrumental temperatures.

]]> By: bender http://climateaudit.org/2008/09/16/my-erice-presentation/#comment-162228 Wed, 17 Sep 2008 20:04:17 +0000 http://www.climateaudit.org/?p=3651#comment-162228 Re: Jeff Id (#27),
RegEM is a method they developed to (legitimately) interpolate missing data. Mann has taken to using it (or something like it?) for extrapolating missing (i.e. future) data. Has this change in application ever been documented or validated in the literature? I do not think so. Correct me if I am wrong.

]]> By: Steve McIntyre http://climateaudit.org/2008/09/16/my-erice-presentation/#comment-162227 Wed, 17 Sep 2008 19:54:07 +0000 http://www.climateaudit.org/?p=3651#comment-162227 #27. Jeff, I’m looking through their code to see how and when their correlations were calculated – before or after infilling. Right now it looks like they were done after infilling. Which makes the whole thing an even worse mess than is on the table right now.

While this may seem opaque to you now, it’s NOTHING like trying to parse MBH when I started. This time, Mann has archived a lot of code. Now it’s lousy code and no one’s been able to make it work just yet, but it gives a clue as to what he did. With MBH, everything was much more of a mystery and it was hard to even get a foothold.

Availability of code makes assessment far more efficient – which is the rationale for archiving code and data in econometrics journals.

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