Why not tell the whole story about Mr. Mann's flawed studies...and little balance please!!

Canadian scientists Stephen McIntyre and Ross McKitrick have uncovered a fundamental mathematical flaw in the computer program that was used to produce the hockey stick. In his original publications of the stick, Mann purported to use a standard method known as principal component analysis, or PCA, to find the dominant features in a set of more than 70 different climate records.

But it wasnt so. McIntyre and McKitrick obtained part of the program that Mann used, and they found serious problems. Not only does the program not do conventional PCA, but it handles data normalization in a way that can only be described as mistaken.

so above all who is the threat to global warming?you see as the name suggeast global warming, its a global issue but if we will all make it our problem then solutions we are trying to find will be meaningful.most of all am a student who is studying Geography and will love to know what scientist are doing to help reduce the rate at which this problem is occuring.

Why not tell the whole story about Mr. Mann's flawed studies...and little balance please!!

Why not, indeed. Please see the exchanges following part1 of the interview: http://global-warming.accuweather.com/2007/02/headline_earth_the_michael_man.html#comment-2631.

More specifically, Mann's data and methodology has been published, replicated, and confirmed -- multiple times.

"Dave", like some others here, has apparently ended up with a greatly exaggerated view of the criticisms of Mann's work -- and a greatly diminished view of the subsequent confirmations of that same research.

A representative example of such confirmation is ROBUSTNESS OF THE MANN, BRADLEY, HUGHES RECONSTRUCTION OF NORTHERN HEMISPHERE SURFACE TEMPERATURES: EXAMINATION OF CRITICISMS BASED ON THE NATURE AND PROCESSING OF PROXY CLIMATE EVIDENCE, Wahl and Ammann,
(http://www.cgd.ucar.edu/ccr/ammann/millennium/refs/WahlAmmann_ClimChange2006.html), published in February of 2006.

From the abstract:
The 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. (emphasis mine)

Just in case the abstract is too thick -- my takeaway reads:
[Our work confirms] 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.

"Anomalous over at least the last 600 years" means "Houston, we have a problem."