Rep. Joe Barton, already implicated in an effort to mislead Congress about the science of climate change, is obviously choosing offence as his best possible defence, renewing his slander of Penn State climate scientist and “Hockey Stick” author Dr. Michael Mann.

As then-co-chair of the House Energy and Commerce Committee, Barton was responsible in 2006 for inviting the increasingly controversial statistician Edward Wegman to prepare a critique of Mann’s iconic hockey-stick-shaped graph illustrating a 1,000-year climate reconstruction. Although Barton has denied that he had a previous relationship with Wegman, implying that the subsequent report and hearing were not a set-up, John Mashey has documented the extensive direction that Barton provided to Wegman through Barton staff member Peter Spencer.

With Wegman and his collaborators in the hockey stick report now under investigation for plagiarism and for inadvertently or intentionally misleading Congress by misrepresenting the actual state of climate science, Mann is (justifiably!) nervous about a renewed Republican witch-hunt should the balance of power shift in the November elections. He wrote an opinion-page piece in the Washington Post (Get the anti-science bent out of politics) to that effect, prompting Barton’s response in a letter to the editor.

Barton dredged up what is becoming an increasingly common line, “Mr. Mann is entitled to make up his own mind, but not his own truth.” It’s perverse, though. Mann’s scientific conclusions have been borne out every time anyone else puts together a climate reconstruction. He has also been exonerated, repeatedly, for the comments he made in the too-famous stolen East Anglia emails. Barton, on the other hand, appears to have his mind firmly set on the position that most favours his oil industry funders – a position that has been repudiated again and again by the scientific community. His opinions appear to be a pointed afront to any reasonably documented set of facts.

An outbreak of Congressional hearings on this issue is, indeed, long overdue. But the record thus far indicates that Barton should be the subject (on charges of misleading the House AND the American people), not the facilitator.