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: 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,



Original CA link


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 ?

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):


Original CA link


Date: 1 Apr 2010, UC

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

(*) after you download the two files , and


6 Responses to “The Trick Timeline”

  1. Hu McCulloch Says:

    UC –
    I’m afraid I can’t tell what’s going on in the last graph.

    It doesn’t help that the original MBH98 5b (the black in your graph) is very hard to read to start with, being in B&W with too many lines at once, even though other figures in the same article are in color. It would be a lot easier to study the smoothing if the standard error lines were omitted, and if the smoothed reconstruction were a heavy solid line rather than a heavy broken line.

    But then, what is your green line? Since you say the red line is “zero padded 5b smooth”, does this make the green line “instrumental (81-95) padded 5b smooth”? But this looks backwards — zero is below the end of the reconstruction, while the 81-95 instrumental data is higher, yet the green line is diving towards zero while the red line is climbing in the last two decades (except, inexplicably, the last few years).

    Then, is one of these supposed to look like the MBH smoothed reconstruction at the end? I don’t see its last few broken segments in your graph at all.

    It’s clear that the trick of splicing instrumental data onto a reconstruction before smoothing and then identifying the product as a smoothed reconstruction has been used several times by Jones et al. But this MBH98 5b is where the original Mike’s Nature Trick would be.

    (I’d agree with Tim Lambert that MBH98 fig. 7 merely plots the two on the same graph as separate lines, and is not splicing them together as if they were one. I’ll mention this over at

  2. Hu McCulloch Says:

    Correction — my comment on fig. 7 is at

  3. UC Says:


    here’s the data
    % Year AnnualRecon Instrumental MB98SmoothTrick MBH98SmoothNoTrick MBH99SmoothTrick MBH99SmoothNoTrick

    I’ll clean & post the code, just a minute

  4. UC Says:

    Code for the “no trick” was here

    load MBHsmooths1.txt

    [B99,A99]=butter(10,2/40); % MBH99
    [B98,A98]=butter(10,2/50); % MBH98


    Now I need to post the “trick” code, just a sec..

  5. UC Says:

    load MBHsmooths1.txt %
    % MBHsmooths1 = [ Year AnnualRecon Instrumental MB98SmoothTrick MBH98SmoothNoTrick MBH99SmoothTrick MBH99SmoothNoTrick ]
    in99=MBHsmooths1(ini,2); % Annual Recon MBH99
    in98=in99(401:end); % Annual Recon MBH98

    Trick=MBHsmooths1(982:996,3); % pad with instrumental (1981..1995) ..
    out98t=flipud(filter(B98,A98,flipud([filter(B98,A98,[in98;Trick;zeros(100,1)])]))); %..then smooth
    out98t=out98t(26:576); % out98t is the smoothed recon ( years 1425..1975 ) in 5b, isn’t it ?

  6. uc00 Says:

    This post is now moved to CA, . Will close the comments here.

Comments are closed.

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