Steyn accused Penn State of covering up Mann's "fraudulent" climate-change data.
Mann has sued the two writers and the CEI, requesting both compensatory and punitive damages. CEI has removed the sentences comparing Mann to Sandusky. National Review has not removed that inflammatory and libelous language.
This is, of course, the latest battle of Mann's 1998 "Hockey Stick" paper. After accusations were made against Mann, a number of investigations were conducted, and every single one exonerated Michael Mann. A dozen or so other scientific investigations were conducted by other research teams (not including Michael Mann), and every single one got results in agreement with Mann's result: the 20th century is anomalously warm, compared with the previous 400 years, and perhaps with the past 1000 years.
Mann received the prestigious 2012 Hans Oeshger Medal from his geoscience colleagues, and as a member of IPCC shared in the Nobel Prize. Mann recently authored a book (The Hockey Stick and the Climate Wars: Dispatches from the Front Lines) on the subject. His Facebook page has more details. (Be sure to search for Michael E. Mann, or you might get the director of the Pink Panther movies).
The climate change deniers are obsessed with the Hockey Stick, thinking that if only that one paper can be refuted, the case for AGW will collapse. In fact there are thousands of papers supporting AGW. If a few papers turn out to be flawed, the central conclusion survives easily.
Again the analogy with evolution: nothing in biology makes sense without the theory of evolution. Evolution is so strongly supported by so many different lines of evidence, that even one actual case of fraud (Piltdown Man) changes very little.
Coverage on Common Dreams
Coverage in Washington Post
The 37-page legal document, filed in DC Superior Court.