Hockey Stick Hoax

The "hockey stick graph" is a reconstruction of the Earth's atmosphere temperature from various proxies such as tree rings, superimposed on the record of thermometer readings from ground-based weather stations. The proxy estimates go back 1,000 years, while the thermometer readings date from 1850.

The UN climate panel (IPCC) decided to stop using the traditionally accepted proxy estimates, which had shown a distinct (and naturally caused) Medieval Warm Period followed by a Little Ice Age. Without giving any reason for this change, they elevated recent recent PhD grantee Michael Mann (based at the highly liberal University of Massachusetts - Amherst to a lead author of one of their assessments.

Mann's graph, which was shaped like a hockey stick, portrayed temperatures as steadily declining since medievel times and then sharply rising in the last century and a half. Notably, his reconstruction fueled claims than 1998 and following years had the highest temperatures in 1,000 years.

Since this was obviously false, many scientists protested. However, Mann initially refused to reveal any of his data or methods - even though his work was supported by the U.S. government - which made it exceedingly difficult for other scientists to replicate his work.

Eventually, McIntyre and McKitrick learned enough about Mann's data and methods to discover where he went wrong. But the political climate was such that it was very difficult for the correct information to find a publisher.

See also

• Politics of global warming