My best friend ever used that Hockey Stick in his second book, even featured the graph. This was in 2005.

On the other hand, Michael Mann, inventor of the hockey stick, has very serious problems. Him, I don’t know. He’s easy to hate and loath. Wikipedia:

Michael E. Mann (born 1965) is an American climatologist and geophysicist,^[1] currently director of the Earth System Science Center at Pennsylvania State University, who has contributed to the scientific understanding of historic climate change based on the temperature record of the past thousand years. He has pioneered techniques to find patterns in past climate change, and to isolate climate signals from “noisy data”.^[3]

As lead author of a paper produced in 1998 with co-authors Raymond S. Bradley and Malcolm K. Hughes, Mann introduced innovative statistical techniques to find regional variations in a hemispherical climate reconstruction covering the past 600 years. In 1999 the same team used these techniques to produce a reconstruction over the past 1,000 years (MBH99) which was dubbed the “hockey stick graph” because of its shape. He was one of 8 lead authors of the “Observed Climate Variability and Change” chapter of the Intergovernmental Panel on Climate Change (IPCC) Third Scientific Assessment Report published in 2001. A graph based on the MBH99 paper was highlighted in several parts of the report, and was given wide publicity. The IPCC acknowledged that his work, along with that of the many other lead authors and review editors, contributed to the award of the 2007 Nobel Peace Prize, which was won jointly by the IPCC and Al Gore.