Editor’s note: The Union accepts one submission per author, per 30-day period, although our policy does afford opportunity for rebuttal on a case-by-case basis in the form of a letter to the editor. However, due to high interest in this timely topic, The Union is publishing Mr. Sauer’s full response to a recent Other Voices submission.

My Sept. 22 column, “If you control carbon, you control life,” questioned the scientific validity of Michael Mann’s “hockey stick.” Dr. Mann wrote an Other Voices article in The Union the next day complaining my statements that his contrived hockey stick ignored the Medieval Warm Period are a “falsehood,” and “a distortion, half-truth, or plain untruth.”

I take this opportunity to buttress the documented truth of what I wrote.

The search for truth starts with understanding that if the Medieval Warm Period existed before the industrial revolution then the man-made global warming (MMGW) theory of CO2 forcing sudden warming in the 20th century is baseless because our recent warming is not unusual, unique, unnatural, nor greenhouse gas related.

In the 1990s, many scientific articles referred to the Medieval Warm Period lasting from about AD 800-1300. This was followed by the Little Ice Age from about 1300 to 1900. These were scientifically undisputed facts.

The United Nation’s Intergovernmental Panel on Climate Change’s (IPCC) was created to officially work on the global warming issue. Its first progress report in 1990 on Page 202 showed a graph in which the Medieval Warm Period was portrayed as clearly warmer than the present.

By 1995, seeking to include CO2 as a cause of warming, the IPCC report started with the Little Ice Age to show a long slow period of increasing temperatures.

Chapter 8 of the scientific report stated: “No study to date has positively attributed all or part (of the climate change observed) to anthropogenic causes.”

Politics prevailed. This statement was removed from the final report. The non-scientific “Summary for Policymakers” read: “The balance of evidence suggests that there is a discernible human influence on global climate.”

By 2001 the IPCC “Summary for Policymakers” had what it wanted: Mann’s “hockey stick” claiming that temperatures in the Northern Hemisphere remained relatively stable over 900 years, spiked upward in the 20th century, and the 1990s was the warmest decade in at least one thousand years.

The problems with Mann’s study were many. First, the hockey stick focused only on temperature trends in the Northern Hemisphere. Second, the widely recognized Medieval Warm Period and the Little Ice Age were completely dismissed.

Third, the hockey stick was formed by crudely grafting the surface temperature record of the 20th century onto a pre-1900 tree-ring record which grafting was innately scientifically flawed.

As mentioned, McIntyre and McKitrick’s assiduous studies concluded Mann’s argument for CO2-caused MMGW was “a carefully worked artificial creation”.

In 1999, a study of tree rings by Keith Briffa of the Climate Research Unit (CRU) of East Anglia University produced a sharp and steady decline in temperature after 1960.

In 2003, Drs. Baliunas and Soon, researchers at the Harvard-Smithsonian Center for Astrophysics, contested the hockey stick conclusion in a publication in “Climate Research.”

After reviewing more than 200 climate studies, they confirmed the Medieval Warm Period and the Little Ice Age were worldwide phenomena not limited to the European and North American continents.

Moreover, they found many parts of the world showed the medieval warmth to be greater than that of the 20th century.

In 2006, the National Academy of Science (NAS) released a study concluding little confidence can be placed in Mann’s concluding the 1990s was likely the warmest decade in the last 1,000 years. (NAS, “Temperature Reconstruction for the Last 2000 Years,” June 2006.) Then, in 2009, “Climategate” revealed leaked emails of East Anglia University’s CRU. (For actual emails, see Sen. James Inhofe, “The Greatest Hoax,” 2012, Appendix C.)

An email from Phil Jones, a CRU climatologist, to Dr. Mann and others dated Nov. 16, 1999, mentions Dr. Mann’s “trick” to hide Briffa’s 1960s’ temperature decline.

Emails of March 11, 2003 between Dr. Mann and Jones, show their displeasure about Baliunas and Soon’s publication in “Climate Review.” Jones’ email threatened to shun Climate Research until “they rid themselves of this troublesome editor.” Echoing Jones, Dr. Mann responded to punish “Climate Research” by encouraging “our colleagues in the climate research community to no longer submit to, or cite papers in, this journal.”

Documentary evidence indicates Dr. Mann is not a disinterested scientist.

He views substantive challenges to his work as heresy. Unlike Dr. Mann, true scientists welcome criticism and debate as an essential to scientific progress.

Dr. Mann launched a petty and invictive OV article calling me a liar. He’s wrong. His “hockey stick” is a documented hoax.

Norm Sauer, who lives in Nevada City, is a member of The Union Editorial Board. His opinion is his own and does not reflect the viewpoint of The Union or its editorial board. Write to him at EditBoard@TheUnion.com.