'Criticism of IPCC
Christopher Landsea resignation
Main article: IPCC Fourth Assessment Report
In January 2005 Christopher Landsea resigned from work on the IPCC AR4, saying that he viewed the process "as both being motivated by pre-conceived agendas and being scientifically unsound" because of Kevin Trenberth's public contention that global warming was contributing to recent hurricane activity.[69] Roger A. Pielke, Jr. who published Landsea's letter writes: "How anyone can deny that political factors were everpresent in the negotiations isn't paying attention [sic]", but notes that the actual report "Despite the pressures, on tropical cyclones they figured out a way to maintain consistency with the actual balance of opinion(s) in the community of relevant experts." He continues "So there might be a human contribution (and presumably this is just to the observed upwards trends observed in some basins, and not to downward trends observed in others, but this is unclear) but the human contribution itself has not been quantitatively assessed, yet the experts, using their judgment, expect it to be there. In plain English this is what is called a 'hypothesis' and not a 'conclusion.' And it is a fair representation of the issue."[70]
Emphasis of the "hockey stick" graph
Main article: Hockey stick controversy
The third assessment report (TAR) prominently featured[71] a graph labeled "Millennial Northern Hemisphere temperature reconstruction" from a paper by Michael E. Mann, Raymond S. Bradley and Malcolm K. Hughes (MBH98[72]) often referred to as the "Hockey Stick Graph".
NOTE THIS SENTENCE (Jim):
This graph differed from a schematic in the first assessment report which depicted larger global temperature variations over the past 1000 years, and higher temperatures during the Medieval Warm Period than the present day. (The schematic was not an actual plot of data.)
The appearance of MBH98 in the TAR was widely construed as demonstrating that the current warming period is exceptional in comparison to temperatures between 1000 and 1900. The methodology used to produce this graph was criticized in an article by Stephen McIntyre and Ross McKitrick.[73] In a 2006 letter to Nature, Bradley, Hughes and Mann pointed out that their original article had said that "more widespread high-resolution data are needed before more confident conclusions can be reached" and that the uncertainties were "the point of the article."'
http://en.wikipedia.org/wiki/Intergover ... sm_of_IPCC
(Note that Michael Mann is one of the central figures in the e mail 'scandal.' As I understand the charges,
these folks are alleged to have tweaked data so as to increase the appearance of warming,
also to hide declining temperature; also they are alleged to have tried to manipulate the peer review process to
prevent criticisms of their work from getting published; also to have done what they could to prevent
releasing their data to the public. East Anglia data appear to have been quite important to IPCC.
The 'hockey stick' is important; Al Gore apparently referred to it. )
Other critics, however, maintain that the IPCC underestimates dangers (check link).
................
Penn State University is investigating Michael Mann, head of its climatology department.
He says he welcomes the investigation.
http://network.nationalpost.com/np/blog ... begin.aspx
