For years, PSU climate scientist Michael Mann, who's worked with the Intergovernmental Panel on Climate Change, has found himself at the center of controversy over his work. That work has demonstrated that we humans are indeed heating up our planet. The enduring image associated with Mann's work is the hockey stick. Now Mann is in effect taking the hockey stick and striking back at his critics. He talks with TAF's Jennifer Szweda Jordan about his book, The Hockey Stick and The Climate Wars: Dispatches From the Front Lines.