Business Insider: Michael Mann, professor of meteorology at Penn State, dropped by Madison, Wis. last week, and we quizzed him about the state of the climate. Mann's post-doctoral work (1) thesis introduced the "hockey stick," a graph showing the accelerated pace of warming, based on records of temperature over previous centuries.
Mann's provocative graph became a core of the effort by former vice-president Al Gore to raise the alarm over global warming. It also became, among global warming deniers, a target of...