Comments on: The Hockey Stick and the Milankovitch Theory http://climateaudit.org/2010/02/03/the-hockey-stick-and-milankovitch-theory/ by Steve McIntyre Thu, 16 Feb 2012 03:49:34 +0000 hourly 1 http://wordpress.com/ By: Moderate Low Weight « Climate Audit http://climateaudit.org/2010/02/03/the-hockey-stick-and-milankovitch-theory/#comment-314790 Sun, 04 Dec 2011 20:35:18 +0000 http://climateaudit.org/?p=10075#comment-314790 [...] (see comments) we began to understand the effect of this ridiculous “CO2-adjustment” (Mannkovitch Bodge) in MBH99: it adjusted the verification RE statistic and affected the 1000-1850 linear trend [...]

]]> By: Hu McCulloch http://climateaudit.org/2010/02/03/the-hockey-stick-and-milankovitch-theory/#comment-259791 Sun, 03 Apr 2011 13:00:13 +0000 http://climateaudit.org/?p=10075#comment-259791 Jean has suggested, over on the new Briffa Bodge post at http://climateaudit.org/2011/03/30/muir-russell-and-the-briffa-bodge/#comment-259525 , that this trick be called the “Milankovitch Bodge”: http://climateaudit.org/2011/03/30/muir-russell-and-the-briffa-bodge/#comment-259525 .

However, I think it does Milankovitch an injustice to associate him with this procedure.

How about the “Mannkovitch CO2 Bodge” instead?

The essay Jean recommends, “A good trick to hide a decline”, by Andrew Montford at http://bishophill.squarespace.com/blog/2010/4/26/a-good-trick-to-create-a-decline.html , provides very readable explanation of all this. Perhaps this is included in his book.

One important thing that I got from Montford’s piece was that the Mannkovitch CO2 Bodge was only applied to the AD 1000-1400 portion of the HS, where it has the effect of raising the early portion of the shaft. If you look closely at the blue annual readings, this discontinuity is actually visible in the altered graph at 1400.

As Montford dryly points out, it is “counterintuitive” that an alteration that supposedly adjusts for post-1900 CO2 fertilization has it entire effect pre-1400!

Like they say, It’s Even Worse Than We Thought! ;-)

]]> By: Hu McCulloch http://climateaudit.org/2010/02/03/the-hockey-stick-and-milankovitch-theory/#comment-229699 Sun, 09 May 2010 15:52:56 +0000 http://climateaudit.org/?p=10075#comment-229699 Maybe Jones was persuaded after he read about it in the authoritative TAR? ;-)

]]> By: Steve McIntyre http://climateaudit.org/2010/02/03/the-hockey-stick-and-milankovitch-theory/#comment-229676 Sat, 08 May 2010 14:07:31 +0000 http://climateaudit.org/?p=10075#comment-229676 108. 0926026654.txt
From: Phil Jones
To: mann@snow.geo.umass.edu
Subject: Straight to the Point
Date: Thu, 06 May 1999 17:37:34 +0100
Cc: k.briffa,t.osborn,mhughes,rbradley

Keith didn’t mention in his Science piece but both of us
think that you’re on very dodgy ground with this long-term
decline in temperatures on the 1000 year timescale. What
the real world has done over the last 6000 years and what
it ought to have done given our understandding of Milankovic
forcing are two very different things. I don’t think the
world was much warmer 6000 years ago – in a global sense
compared to the average of the last 1000 years, but this is
my opinion and I may change it given more evidence.

]]> By: Climate Research News » Bishop Hill: The Hockey Stick and the Milankovitch Cycle http://climateaudit.org/2010/02/03/the-hockey-stick-and-milankovitch-theory/#comment-228861 Tue, 27 Apr 2010 06:31:11 +0000 http://climateaudit.org/?p=10075#comment-228861 [...] but was rather overlooked by the sceptic community in all the excitement over the emails. “The Hockey Stick and the Milankovitch Cycle” uses some of the Climategate files to solve one of the remaining mysteries of the Hockey [...]

]]> By: Best Kids Movies in 2009 by Popular Demand | Movie Ticket and News http://climateaudit.org/2010/02/03/the-hockey-stick-and-milankovitch-theory/#comment-219626 Thu, 04 Feb 2010 15:13:32 +0000 http://climateaudit.org/?p=10075#comment-219626 [...] The Hockey Stick and the Milankovitch Theory « Climate Audit [...]

]]> By: UC http://climateaudit.org/2010/02/03/the-hockey-stick-and-milankovitch-theory/#comment-219615 Thu, 04 Feb 2010 14:14:27 +0000 http://climateaudit.org/?p=10075#comment-219615 Actually, original PC1 is not needed for positive ver REs. One can just apply partially centered PCA to trendless red noise [1] and take the first ‘noise PC’. It won’t take many simulations to obtain a hockey stick that passes the positive RE requirement.

[1] McIntyre, S., and R. McKitrick (2005), Hockey sticks, principal components, and spurious significance, Geophys. Res. Lett., 32, L03710, doi:10.1029/2004GL021750.

]]> By: Jean S http://climateaudit.org/2010/02/03/the-hockey-stick-and-milankovitch-theory/#comment-219588 Thu, 04 Feb 2010 09:20:50 +0000 http://climateaudit.org/?p=10075#comment-219588 Re: Bob McDonald (Feb 3 17:35),
Nothing I’m aware of.

I did the graph by standardizing all series (three “fixed” PCs plus the “rescaled” original PC) to zero mean and unit variance in the “pre-fixing era” (1000-1599), where they are exactly the same. Then I subtracted from the original each of the fixed PCs.

]]> By: Geoff Sherrington http://climateaudit.org/2010/02/03/the-hockey-stick-and-milankovitch-theory/#comment-219558 Thu, 04 Feb 2010 05:59:24 +0000 http://climateaudit.org/?p=10075#comment-219558 Maybe email 963233839.txt of 10 July 2000 is relevant.

Goodness, the climate science community learned a lot about ignoring objections between 2000 and the closing date for submissions to AR4 in 2007.

]]> By: Super Green, putting your retirement in Al Gores hands? « TWAWKI http://climateaudit.org/2010/02/03/the-hockey-stick-and-milankovitch-theory/#comment-219501 Thu, 04 Feb 2010 01:00:44 +0000 http://climateaudit.org/?p=10075#comment-219501 [...] climategate, More on the hockey stick, Manns misconduct – [...]

]]>