DC Jury Finds Climate Skeptics Defamed ‘Hockey Stick’ Model Creator — 12 Years Later

DC Jury Finds Climate Skeptics Defamed ‘Hockey Stick’ Model Creator — 12 Years Later

Nick Pope on February 8, 2024

A Washington, D.C., jury ruled in favor of University of Pennsylvania climate scientist Michael Mann on Thursday in a defamation case he brought against two critics of his work more than a decade ago.

Mann first filed the defamation suit in October 2012 against Rand Simberg, who compared Mann to convicted pedophile Jerry Sandusky for Mann’s alleged data manipulation in his signature 1998 “hockey stick” climate model in a blog post for the Competitive Enterprise Institute (CEI), and Mark Steyn, a right-of-center political pundit who referenced Simberg’s blog post in his own writing about the “hockey stick” model for National Review. Steyn will reportedly have to pay $1 million in damages, while Simberg will have to pay $1,000, according to The New York Times.

National Review and CEI were also defendants in the lawsuit initially, but a 2021 court order resulted in those organizations being dropped from Mann’s suit. Mann worked at Pennsylvania State University at the time of the blog posts, a school where Sandusky coached football for years before the child sex abuse scandal exploded in 2011.

The “hockey stick” model combined a number of different climate proxies into a single model, purportedly showing that global temperatures have risen sharply in the past several decades compared to the preceding centuries.

Critics, including Steyn and Simberg, have attacked the “hockey stick” model for years, generally asserting that should not be considered an authoritative assessment of climate trends because of its perceived flaws. Mann, for his part, has effectively used his experiences defending his work to label himself as a martyr resisting supposedly malicious attacks launched by climate skeptics.

While Mann won the case, Abraham Wyner, a tenured statistics professor and the chair of the undergraduate statistics program at the University of Pennsylvania’s Wharton School, testified that Mann engaged in “improper manipulation” of data that made his signature model “misleading,” according to National Review. Judith Curry, a climatologist who has been critical of Mann in the past, said that Mann falsely suggested she had essentially traded sex for career advancement.

Before National Review was dropped from the suit, Mann wrote in emails that the outlet is a “filthy organization” that is a “threat to our children,” according to National Review. Additionally, Mann wrote in 2012 communications that he considers Steyn to be a “pathetic excuse for a human being” whom he hoped the defamation suit would “ruin.”

The case was about “the ability of myself and others to speak freely about the most important issues of our day, whether climate change or another issue,” Simberg told The Associated Press before the verdict came down. “If others are faced with over a decade of litigation for giving their opinions, we will all suffer.”

Other climate scientists followed Mann’s case carefully, Kate Cell, a senior climate campaign manager for the union of Concerned Scientists, told the AP.

Many of these scientists were hoping for a favorable outcome for Mann in order to “reduce the comfort and regularity with which those who do not accept climate change science speak, and speak very nastily, about climate scientists,” Cell told the AP.

Notably, Mann contributed to the United Nations (UN) Intergovernmental Panel on Climate Change (IPCC) in 2007; the IPCC, as an institution, won the Nobel Prize for “its efforts to build up and disseminate greater knowledge about man-made climate change and to lay the foundations for the measures that are needed to counteract such change” that year alongside former Vice President Al Gore.

The IPCC subsequently released a 2012 statement clarifying that the prize was for the institution rather than to be claimed by individual members and contributors. Mann insinuated in the original complaint against Steyn and Simberg that he had won a Nobel Prize.