More recently, Mann battled back in a 2004 corrigendum in the journal Nature, in which he clarified the presentation of his data. He has also shown how errors on the part of his attackers led to their specific results. For instance, skeptics often cite the Little Ice Age and Medieval Warming Period as pieces of evidence not reflected in the hockey stick, yet these extremes are examples of regional, not global, phenomena. "From an intellectual point of view, these contrarians are pathetic, because there's no scientific validity to their arguments whatsoever," Mann says. "But they're very skilled at deducing what sorts of disingenuous arguments and untruths are likely to be believable to the public that doesn't know better."

Mann thinks that the attacks will continue, because many skeptics, such as the Greening Earth Society and the Tech Central Station Web site, obtain funds from petroleum interests. "As long as they think it works and they've got unlimited money to perpetuate their disinformation campaign," Mann believes, "I imagine it will go on, just as it went on for years and years with tobacco until it was no longer tenable--in fact, it became perjurable to get up in a public forum and claim that there was no science" behind the health hazards of smoking.