Insights: Behind the Hockey Stick; March 2005; Scientific American Magazine; by David Appell; 2 Page(s)

Michael Mann knows his students and his subject. The topic of the graduate seminar: El Ni¿o and radiative forcing. The beer he will be serving: Corona, "because I'm going to be talking about tropical climate." Not surprisingly, attendance is high.

Mann is most famously known for the "hockey stick," a plot of the past millennium's temperature that shows the drastic influence of humans in the 20th century. Specifically, temperature remains essentially flat until about 1900, then shoots up, like the upturned blade of a hockey stick. The work was also the first to add error bars to the historical temperatures and allow for regional reconstructions of temperature.