I must object to this entire theory, as it is based on shaky assumptions. In support, I give you Dr. Timothy Ball:

http://www.canadafreepress.com/2007/global-warming020507.htm

I was a bit surprised by the interview with Michael Mann. His "hockey stick" graph of global warming has been discredited. He resisted releasing the computer code that generated his famous graph but once he did it was found to be fatally flawed; the math function was faulty. His program produced the same hockey stick graph when bogus data was entered. Also, Mann relied on tree rings from a single tree for one data point which is simply insufficient. Michael Mann is not a source I would rely upon for scientific evidence in support of global warming.

Timothy Ball is a charlatan who plays VERY loose with the truth and the facts. When he can't even seem to get the facts straight about his own career as a "professor", why would anyone rely on him for anything else?

For example, Ball claims (http://www.john-daly.com/guests/martin.htm) to be "one of the first climatology PhDs in the world", and proudly proclaims that he is "28 Years Professor of Climatology at the University of Winnipeg."

The truth is that Canada alone had Kenneth Hare, Andre Robert, and Timothy Oke. Ball's PhD is in Geography, not Climatology. Ball, in a different forum (http://www.desmogblog.com/sites/beta.desmogblog.com/files/TBall%20statement%20of%20claim.pdf) , says that his first professorship was awarded in 1988. He retired from the University of Winnipeg in 1996 -- an EIGHT year career. During his career, Ball published a total of FOUR pieces of original research in a peer-reviewed journal.

In short, the truth and facts of his credentials are at wide variance with his claims about them.

The difference between Ball and Mann is that Mann participates in the "candid and frank exchange of views" that characterises healthy scientific dialog.

A reasonable summary of the "hockey stick controversy" is available at wikipedia (http://en.wikipedia.org/wiki/Hockey_stick_controversy).

In healthy scientific dialog, when aspects of a particular theory or methodology are found to be incorrect or inaccurate, those discoveries are first validated and then celebrated. We still appear to be in the "validation" phase of the challenges to the overall theory advocated by Mann. I fear that Ressler overstates both Mann's alleged resistance to validation and also the criticism of his reports.

I would be interested in seeing cites to support Ressler's allegation that "[Mann] releasing the computer code that generated his famous graph."

Brookline can find support for my earlier post at:
http://www.multi-science.co.uk/index.htm
The article is by Ross McKitrick and Stephen McIntyre.
Others have verified their findings concerning the flawed methodology employed by Mann including inaccurate, unreliable and extrapolated data. See the summary of the Wegman Panel Report at:
http://www.ecolo.org/documents/documents_in_english/hock-joke-Wegman_facts-06.pdf

Mann has provided his data sources but refused to share the computer program he used stating that it is, "a private piece of intellectual property." See his entire response to the Wegman Panel's inquiry at:
http://www.realclimate.org/Mann_response_to_Barton.pdf

Some have referred to Mann's work as "Mann-made global warming." I tend to agree with their assessment. With so much information available on this subject, I am surprised to find that people still find the "hockey stick" credible. I guess it's like the newspaper retraction of yesterday's sensational headline - nobody notices it on page 22. But unlike the newspaper, Mann appears to still be defending the validity of his work. Someone should tell him to simply acknowledge his errors and keep trying. Isn't that what scientists are supposed to do? This makes me question his motives - are they scientific or political?

Thanks for the cites, Rick. Even a cursory reading of the Wikipedia entry I cited leads to the various pieces published by McKitrick and McIntyre.

In your piece, you wrote:
He resisted releasing the computer code that generated his famous graph but once he did it was found to be fatally flawed; the math function was faulty. His program produced the same hockey stick graph when bogus data was entered.

This allegation seems inconsistent with the material you cited in support (as well as with the material summarized in the Wikipedia entry). Mann has not released his "computer code", nor should he be expected to -- for a variety of reasons laid out rather clearly in the response from the NSF:

I apologize if my last electronic message was not clear but let me clarify the US NSF's view in this current message. Dr. Mann and his other US colleagues are under no obligation to provide you with any additional data beyond the extensive data
sets they have already made available. He is not required to provide you with computer programs, codes, etc. His research is published in the peer-reviewed literature which has passed muster with the editors of those journals and other
scientists who have reviewed his manuscripts. You are free to your analysis of climate data and he is free to his. The passing of time and evolving new knowledge about Earth's climate will eventually tell the full story of changing climate. I would expect that you would respect the views of the US NSF on the issue of data access
and intellectual property for US investigators as articulated by me to you in my last message under the advisement of the US NSF's Office of General Counsel.

Mann's data has been published, his methodology has been published. Here's what Mann wrote:
The data, descriptions of methods, and results related to my research � more than sufficient to permit other researchers to replicate the research � have been extensively archived (in many cases, in several archives) on public websites, and data
links within the websites. [The website addresses are:]
http://fox.rwu.edu/~rutherfo/supplements/jclim2003a/
http://www.ngdc.noaa.gov/paleo/pubs/jones2004/jones2004.html
http://www.ngdc.noaa.gov/paleo/pubs/mann2003b/mann2003b.html
http://www.ngdc.noaa.gov/paleo/pubs/mann2003/mann2003.html
http://www.ngdc.noaa.gov/paleo/ei/ei_cover.html
http://www.ncdc.noaa.gov/paleo/ei/ei_datarev.html
http://www.ncdc.noaa.gov/paleo/ei/ei_reconsa.html
http://www.ncdc.noaa.gov/paleo/ei/ei_reconsb.html
http://www.ncdc.noaa.gov/paleo/ei/ei_reconsc.html
http://www.ncdc.noaa.gov/cgi-bin/paleo/mannplot2.pl
http://www.ncdc.noaa.gov/paleo/ei/data_supp.html
http://www.ncdc.noaa.gov/paleo/ei/stats-supp-annual.html
http://www.ncdc.noaa.gov/paleo/ei/stats-supp-cold.html
http://www.ncdc.noaa.gov/paleo/ei/stats-supp-warm.html
http://www.ncdc.noaa.gov/paleo/ei/ei_nodendro.html
ftp://ftp.ngdc.noaa.gov/paleo/paleolimnology/newengland/glacial_lake_hitchcock/
ftp://eclogite.geo.umass.edu/pub/mann/MANNETAL98/nino3.dat
ftp://eclogite.geo.umass.edu/pub/mann/ONLINEPREPRINTS/Millennium/DATA/RECONS/
ftp://holocene.evsc.virginia.edu/pub/sdr/temp/nature/MANNETAL98/
http://www.ngdc.noaa.gov/paleo/pubs/mann1998/frames.htm
ftp://eclogite.geo.umass.edu/pub/mann/MANNETAL98/
ftp://holocene.evsc.virginia.edu/pub/MBH98/
ftp://holocene.evsc.virginia.edu/pub/MANNETAL98/
ftp://holocene.evsc.virginia.edu/pub/MANNETAL98/FIGUREDATA/
ftp://holocene.evsc.virginia.edu/pub/MANNETAL98/INSTRUMENTAL/
ftp://holocene.evsc.virginia.edu/pub/MANNETAL98/METHODS/
ftp://holocene.evsc.virginia.edu/pub/MANNETAL98/PROXY/
ftp://holocene.evsc.virginia.edu/pub/mann/Filter/lowpass.m
ftp://holocene.evsc.virginia.edu/pub/mann/Filter/lowpassmin.m
http://www.atmos.ucla.edu/tcd/ssa/
http://holocene.evsc.virginia.edu/Mann/tools/MTM-RED
http://holocene.evsc.virginia.edu/Mann/tools/MTM-COHERE
http://holocene.evsc.virginia.edu/Mann/tools/CMPLXDEMOD
http://holocene.evsc.virginia.edu/Mann/tools/MTM-SVD

This is hardly a researcher attempting to hide his data.

Here's more, from Mann, regarding the reproducability of his results:
All of the proxy data (tree-rings, coral, ice cores, and historical documents) used in Mann et al. (1998) has been available since May 2000 on
this public website: ftp://holocene.evsc.virginia.edu/pub/MBH98. The
methodology used by my colleagues and me is described in detail in the initial publication, and further expanded upon in July 2004 on Nature�s supplementary website
(http://www.nature.com/nature/journal/v430/n6995/suppinfo/nature02478.html)
and on our own website, ftp://holocene.evsc.virginia.edu/pub/MANNETAL98.
Moreover, independently-derived source codes for implementing our algorithm, and all required input data, have been posted on the website of the National Center for Atmospheric Research. See
http://www.ucar.edu/ccr/ammann/millennium/CODES_MBH.html. For these reasons, charges that our work is not subject to replication are unfounded. The
initial description of the work was sufficient to permit researchers to independently produce the key algorithms. See, e.g., Zorita, E., F. Gonzalez-Rouco, and S. Legutke, Testing the Mann et al.(1998) approach to paleoclimate reconstructions in the context of a 1000-yr control simulation with the ECHO-G Coupled Climate Model, J. Climate, 16, 1378-1390 (2003); Von Storch, H., E. Zorita, J.M. Jones, Y. Dimitriev, F. Gonzalez-Rouco, F., and S.F.B. Tett, Reconstructing Past Climate from Noisy Data, Science, 306, 679-682 (2004). Not only have we replicated our results with a different methodology (Rutherford, S., Mann, M.E., Osborn, T.J., Bradley, R.S., Briffa, K.R., Hughes,
M.K., Jones, P.D., Proxy-based Northern Hemisphere Surface Temperature Reconstructions: Sensitivity to Methodology, Predictor Network, Target Season
and Target Domain, Journal of Climate (2005) (to appear in July issue), but an independent group has replicated our original methods and results (See Wahl, E.R. and Ammann, C.M., Robustness of the Mann, Bradley, Hughes Reconstruction of Surface Temperatures: Examination of Criticisms Based on the Nature and Processing of Proxy Climate Evidence, Climatic Change (2005)
(forthcoming)).

In short, Mr. Ressler, your attempted "summary" of Mann's research seems to be at wide variance with the facts -- even as reported in the very links you yourself cited.

At the moment, it appears to me that Dr. Mann is a far more "reliable source [to] rely upon for scientific evidence" than you have been so far.

Brookline, I guess you can believe in Mann's hockey stick if you wish but I find it troubling. The "computer code" that Mann refuses to release is the program he used to process all of the data. He did release all of his sources but his work could not be independently replicated even though he claims it could. Maybe that computer program he used contained errors; I guess we'll never know.

The errors found by McKitrick and McIntyre which were independently confirmed by the Wegman Panel make the conclusions Mann reached problematic. The IPCC sure liked his work though and he gained much notoriety because of it even though it is most likely false. Why didn't the IPCC check this out before they jumped on the bandwagon?

Human induced global warming remains a hypothesis and Mann's work did nothing to transform it into a scientific fact. The way I see it, bad data + bad methodolgy = bad science. I'm not ready to buy Mann's bill of goods because he says so - I demand verifiable scientific evidence and so far I haven't seen any.

Brookline, I guess you can believe in Mann's hockey stick if you wish but I find it troubling.

Science is not about "belief". It's about what you can or cannot show, derive, test, or prove.

The "computer code" that Mann refuses to release is the program he used to process all of the data. He did release all of his sources but his work could not be independently replicated even though he claims it could. Maybe that computer program he used contained errors; I guess we'll never know.

I cited, above, the published replication of Mann's results. You can read them yourself at http://www.cgd.ucar.edu/ccr/ammann/millennium/refs/WahlAmmann_ClimChange2006.html.

From the abstract (emphasis mine):
he Mann et al. (1998) Northern Hemisphere annual temperature reconstruction over 1400-1980 is examined in light of recent criticisms concerning the nature and processing of included climate proxy data. A systematic sequence of analyses is presented that examine issues concerning the proxy evidence, utilizing both indirect analyses via exclusion of proxies and processing steps subject to criticism, and direct analyses of principal component (PC) processing methods in question. Altogether new reconstructions over 1400-1980 are developed in both the indirect and direct analyses, which demonstrate that the Mann et al. reconstruction is robust against the proxy-based criticisms addressed. In particular, reconstructed hemispheric temperatures are demonstrated to be largely unaffected by the use or non-use of PCs to summarize proxy evidence from the data-rich North American region. When proxy PCs are employed, neither the time period used to "center" the data before PC calculation nor the way the PC calculations are performed significantly affects the results, as long as the full extent of the climate information actually in the proxy data is represented by the PC time series. Clear convergence of the resulting climate reconstructions is a strong indicator for achieving this criterion. Also, recent "corrections" to the Mann et al. reconstruction that suggest 15th century temperatures could have been as high as those of the late-20th century are shown to be without statistical and climatological merit. Our examination does suggest that a slight modification to the original Mann et al. reconstruction is justifiable for the first half of the 15th century (~ +0.05�), which leaves entirely unaltered the primary conclusion of Mann et al. (as well as many other reconstructions) that both the 20th century upward trend and high late-20th century hemispheric surface temperatures are anomalous over at least the last 600 years. Our results are also used to evaluate the separate criticism of reduced amplitude in the Mann et al. reconstructions over significant portions of 1400-1900, in relation to some other climate reconstructions and model-based examinations. We find that, from the perspective of the proxy data themselves, such losses probably exist, but they may be smaller than those reported in other recent work.

In short, Mann's work WAS replicated. Ressler is either unaware of this, in which case he should better inform himself, or he IS aware of this, in which case he would be better served to simply speak and write the truth.

I demand verifiable scientific evidence and so far I haven't seen any.

The "verifiable scientific evidence" is directly in front of us, here on this thread. Not only verifable, but verified.

There is nobody so blind as one who refuses to see.