The Trick Timeline

Date: 16 Nov 1999, Phil

I’ve just completed Mike’s Nature trick of adding in the real temps
to each series for the last 20 years (ie from 1981 onwards) amd from
1961 for Keith’s to hide the decline.

Date: 22 Dec 2004, mike

 

No researchers in this field have ever, to our knowledge, “grafted the thermometer record onto” any reconstruction. It is somewhat disappointing to find this specious claim (which we usually find originating from industry-funded climate disinformation websites) appearing in this forum. Most proxy reconstructions end somewhere around 1980, for the reasons discussed above. Often, as in the comparisons we show on this site, the instrumental record (which extends to present) is shown along with the reconstructions, and clearly distinguished from them (e.g. highlighted in red as here).

Date: 21 Nov 2005, Steve

The MBH versions illustrated also splice reconstruction and instrumental values. Thus, Crowley made two different splices of the temperature record into the proxy record. One splice is made in 1965, with proxy values for the 13-site composite (see below) before 1965 and instrumental values from 1965 to 1998 (with the 11-point smooth version ending in 1993). A second version is spliced in 1870, with proxy values from the 13-site composite before 1870 and instrumental records after wards.

Date: 6 May 2009, UC

Let’s see; I think this is made by padding with zeros, but 1981-1998 instrumental is grafted onto reconstruction:

(larger image here )

I used Mann’s lowpass.m , modified to pad with zeros instead of mean of the data,

out=lowpass0(data,1/40,0,0);

mbh99smooths

Original CA link

Backup

Date: 20 Nov 2009, UC

“I’ve just completed Mike’s Nature trick of adding in the real temps
to each series for the last 20 years (ie from 1981 onwards) amd from
1961 for Keith’s to hide the decline”

Is this about the MBH99 smooth ?

http://www.climateaudit.org/?p=1553#comment-340175

http://www.climateaudit.org/?p=1553#comment-340207

Date: 20 Nov 2009, gavin

[Response: This has nothing to do with Mann's Nature article. The 50-year smooth in figure 5b is only of the reconstruction, not the instrumental data. - gavin]

Date: 21 Nov 2009, gavin

And it remains unclear why this was described as Mann’s Nature trick since no such effect is seen in Mike’s paper in any case. – gavin]

Date: 22 Nov 2009, mike

In some earlier work though (Mann et al, 1999), the boundary condition for the smoothed curve (at 1980) was determined by padding with the mean of the subsequent data (taken from the instrumental record).

Date: 24 Nov 2009, CRU

To produce temperature series that were completely up-to-date (i.e. through to 1999) it was necessary to combine the temperature reconstructions with the instrumental record, because the temperature reconstructions from proxy data ended many years earlier whereas the instrumental record is updated every month. The use of the word “trick” was not intended to imply any deception.

Date: 25 Nov 2009, Jean S

UC has corrected me on the fact that adding the instrumental series to the proxy data prior smoothing was used already in MBH98 (Figure 5b), so, unlike I claimed in #66, “Mike’s Nature trick” is NOT a misnomer.

Date: 25 Nov 2009, UC

..and here’s instrumental (81-95)+zero padded Fig 5b smooth (red):

mbh98smooths

Original CA link

Backup

Date: 1 Apr 2010, UC

April Fools, here’s the turn-key(*) code

(*) after you download the two files , http://www.climateaudit.info/wp-content/uploads/2009/11/mbhsmooths1.txt and http://uc00.files.wordpress.com/2010/05/mbh985b.png

 

Date: Aug 29 2014, Jean S

nails it,

MBH98 has 50-year smoothing with padding of 1981-1995 instrumental. Additionally, the smoothing is cut back 25 samples (half of the “filter length”) from both ends. MBH99 used 40-year filtering with 1981-1997 (not 1998!) instrumental padding. The smooth is cut back 20 samples from the end but not from the beginning.

 

 

5 Comments

  1. Posted Mar 7, 2012 at 2:58 PM | Permalink

    Climate Wars:

    ..we supplemented our plot of reconstructed temperatures in MBH98 by additionally showing the instrumental temperatures, which extended through the 1990s. That allowed our reconstruction of past temperatures to be viewed in the context of the most recent warming. The separate curves for the proxy reconstruction and instrumental temperature data were clearly labeled, and the data for both curves were available in the public domain at the time of publication for anyone who wanted to download them.

    That, in short, was the “trick” that Jones had chosen to use to bring the proxy temperature series in his comparison up to the present, even though the proxy data themselves ended several decades earlier. There was one thing Jones did in his WMO graph, however, that went beyond what we had done in our Nature article: He had seamlessly merged proxy and instrumental data into a single curve, without explaining which was which. That was potentially misleading, though not intentionally so; he was only seeking to simplify the picture for the largely nontechnical audience of the WMO report.

  2. Posted Nov 28, 2012 at 5:19 PM | Permalink

    Added link to Steve’s 2005 post.

    mike,
    “The separate curves for the proxy reconstruction and instrumental temperature data were clearly labeled, and the data for both curves were available in the public domain at the time of publication for anyone who wanted to download them.”
    But RECONSTRUCTED (50 YEAR LOWPASS) seamlessly merges proxy and instrumental? Or not?

  3. UC
    Posted Feb 13, 2014 at 4:41 PM | Permalink

    The story does not end here, Jean S has something new, http://rankexploits.com/musings/2014/the-meaning-of-r2-in-pictures-mann-v-steynsimbergceinro/#comment-123713 , http://climateaudit.org/2010/04/01/code-the-trick/ will be updated soon..

    • pottereaton
      Posted Feb 15, 2014 at 2:43 PM | Permalink

      First link leads to an error message, UC.

      theduke

      • pottereaton
        Posted Feb 15, 2014 at 2:45 PM | Permalink

        actually, after re-checking, it’s a zblock message, which I don’t really understand, but it might be a problem only on my end.

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  1. [...] issue of  the “trick” of “hiding the decline” has been discussed again and again and again, and while the wording may be regrettable, the intent was not to deceive but to keep out [...]

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