This podcast is about Science and a chart. Team leader, Professor Michael Mann, drew it 20 years ago using good science. It's been named "The Hockey Stick Graph" because of the way it shoots up. It had no new information. Instead it drew on an international scientific consensus.

The issue was that it suggested that humans had already changed our climate. The other problem was the clarity with which it expressed those man-made forces. You didn't need to be a scientist read or understand it. Dr Michael Mann, like Charles Darwin, dared to publish. The self-evident conclusion by many, unleashed powerful interests against both Dr. Mann and the science community. Dr Karl Talks with him about the experience.