A Different Kind of Hide the Decline
Posted by Jeff Id on December 6, 2009
This is a serious one which has not been covered yet.
In the past year, there has been substantial discussion on CA, WUWT, tAV and other blogs about the filter types used to present temperature data. We evil deniers found that “scientists” have been stiffening the ends of their filters to make sure that the uptrends in graphs look as scary as possible. I personally have been censored from advocate global warming blogs for even suggesting that the practice was be going on. Now we have PROOF that it’s been colluded for.
I’m not sure if readers get the fact that scientists were not speaking openly by email but have been careful not to reveal their bias (especially in the more recent emails). Just not as careful as if talking to reporters. Like other smart scientists, Michael Mann was careful throughout the emials not to reveal his position on these things. After all, if guy’s like Mann knowingly create artificial hockeysticks for a living, you don’t expect them to write it down.
He went a bit too far in this email though.
Look at how Michael Mann writes this;
Michael E. Mann wrote:
Several you have inquired about the below claims by the notorious “Idso brothers” which
relates to the paper by Mann and Jones that appeared in GRL a couple weeks ago.
Of course, its the usual disinformation we’ve come to expect from these folks, but a few
details on why:
1) The supposed “Co2 fertilization” argument is a ruse. The only evidence that such an
effect might actually play some role in tree-growth trends has been found in high
elevation sites in western North America (consult Malcolm Hughes for more details). As
in Mann et al ’99 (GRL), any such effect, to the extent it might exist, has been removed
from the relevant series used in the latest (Mann and Jones) paper through the removal
of anomalous differences between low-elevation and high-elevation western North American
temperature trends during the post 1800 period, prior to use of the data in climate
2) We haven’t in the past extended the proxy reconstruction beyond 1980 because many of
the proxy data drop out. However, the repeated claim by the contrarians that post-1980
proxy data don’t show the warming evident in the instrumental record has finally
prompted me to go ahead and perform an additional analysis in which the
proxy-reconstruction is extended forward as recently as at all possible (to 1995, for
which 3 out of 8 of the NH records are available, and 1 of the 5 SH records are
available). The SH and GLB reconstructions are thus obviously tenuous at best, but they
do address, to the extent at all possible, the issue as to whether or not the proxy
reconstructions show the post-1980 warming–and they do.
See the attached plot which compares the NH (blue), SH (green), and GLB (red) series
through 1995. The late 20th century is the nominal maximum for all 3 series *without any
consideration of the information in the instrumental mean series*. This thus refutes
the 2nd criticism cited by the Idso brothers.
One note about the 40 year smoothing. As in the trends in the instrumental series shown
by Mann and Jones, a boundary constraint on the 40-year smooth has been used that
minimizes the 2nd derivative at the boundary–this trends to preserve the trend near the
end of the series and has been argued as the optimal constraint in the present of
nonstationary behavior near the end of a time series (Park, 1992; Ghil et al, 2002). I
favor the use of this constraint in the smoothing of records that exhibit a significant
trend as one approaches the end of the available data. This might be worth talking about
in the next IPCC when the subject of adopting uniform standards for smoothing data, etc.
In retrospect, Phil and I should have included this analysis in the GRL article, but its
always hard to know what specifics the contrarians are going to target in their attacks.
This analysis however, will be included in a review paper by Jones and Mann on “climate
in past millennia” that is presently being finalized for “Reviews of Geophysics”.
I hope that helps clarify any questions any of you might have had. Please feel free to
pass this information along to anyone who might benefit from it.
Now, back to fighting the “Shaviv and Veizer” propaganda along w/ Ben Santer and David
Parker out in Italy…
The bold is the critical part. Stiffening the 2nd derivative is math code for ‘hide the decline’ . He’s discussing it and trying to rationalize the moronic practice through science. This is one of the most biased statements in the entire email set in my opinion and is flat, slap you in the face evidence of the bias Mann continually imparts to science. This is the another form of Hide the decline. The original had to do with Phil Jones deliberately hiding data which didn’t agree using hidden and undisclosed mathematical methods. This method, is similarly ‘black box’ and is based on the assumption that the upslope of the previous twenty years will match the next.
But Mann is smart. Consider though if it was such a minor point, why would he resort to discussing filters in the context of other papers? Why would he try to standardize the approach? Would the other scientists change their minds based on the goofy explanation? The explanation is for you the accidental reader and only partially for them. In plain English he’s saying, look we have an excuse we can fall back on — what do you think?
This is ugly ugly science, written with the intent to hide the decline and make things ‘ worse than we thought’. There are endless examples of this in these emails. Since PNAS is investigating Mann (yeah right) perhaps they ought to be looking for a pattern in behavior.