We've seen a lot of criticism of Mann et. al and the 'hockey stick' recently. There is some debate as to whether their study employed good statistical methods or if its statistics were critically flawed. Wegeman - one of the main critics of Mann's methods - concluded "Method Wrong + Answer Correct = Bad Science." In other words, he thinks Mann's method was flawed, but agreed with the general result.
http://www.amstat-online.org/sections/envr/ssenews/ENVR_9_1.pdf
Interestingly, in that same newsletter there was a discussion of the Christy and Spencer satellite data. From page 4:
"John Christy and Roy Spencer, published a series of papers showing a slight cooling of temperatures in the troposphere, in contradiction to all physical theories of global warming...other groups started reanalyzing the raw satellite data...these studies had different conclusions from Christy and Spencer, that did show an increasing trend in the troposphere, consistent with the projections of climate models...the new analyses were largely correct, thus resolving an issue that had been at the center of scientific debates over global warming since the original Christy-Spencer papers."
So how can people criticize Mann for his possibly flawed statistical analysis (which nevertheless yielded largely correct results) and dismiss virtually all scientists and evidence supporting AGW, but then turn around and cite Spencer and/or Christy (whose statistical analysis of satellite data was completely wrong) as reason to be skeptical of AGW?
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