Penn climate scientist wins $1 million defamation lawsuit against right-wing bloggers

University of Pennsylvania professor and climate scientist Michael Mann won a defamation lawsuit against a pair of right-wing bloggers who compared his depictions of global warming to a convicted child molester over a decade ago.

A civil trial jury on Thursday found that writers Rand Simberg and Mark Steyn defamed Mann in blog posts they wrote in 2012. The Superior Court of the District of Columbia jurors awarded Mann more than $1 million, deeming the statements in the blogs to have been made with “maliciousness, spite, ill will, vengeance or deliberate intent to harm.”

The outcome marks a significant victory amid a wave of attacks against scientists working on environmental issues, including climate change and health-related issues like vaccines.

“I hope this verdict sends a message that falsely attacking climate scientists is not protected speech,” Mann said in a statement. “It’s a good day for science.”

Climate change continues to be a divisive and highly partisan issue in the United States. A 2023 poll from The Associated Press-NORC Center for Public Affairs Research found that 91% of Democrats believe climate change is happening, while only 52% of Republicans do.

Still, as noted by the Washington Post, critics worried the case’s results could also cause negative effects on free speech.

Here are more details on the case and what happens next.

Michael Mann, 58, is a climate scientist who serves as the director for Penn’s Center for Science, Sustainability & the Media. He’s a professor at the university’s Department of Earth and Environmental Science. His work has mainly focused on climate change and its impact on the world and he’s released several books on the subject. Mann worked at Pennsylvania State University for 17 years before moving to Penn in 2022.

In 1998, a passage with a graph that Mann contributed to the journal Nature garnered attention for dramatically illustrating global warming’s impact on the planet. The graph was called the “hockey stick” for its sharp line pointing upward.

The work brought Mann wide exposure but also many skeptics, including the two writers the scientist took to court for comments that he said affected his career and reputation.

In 2012, the libertarian think tank Competitive Enterprise Institute published a blog post by Simberg, who at the time was a fellow at the organization, comparing Mann’s work to the case of Jerry Sandusky, a former assistant football coach at Pennsylvania State University (where Man was also working at the time) who was convicted of sexually assaulting children.

Mann’s research had been investigated after his and other scientists’ emails were leaked in 2009 in an incident that brought scrutiny of the “hockey stick” graph, with skeptics claiming Mann manipulated data. Investigations by Penn State and others found no misuse of data by Mann, but his work continued to draw attacks, particularly from conservatives.

“Mann could be said to be the Jerry Sandusky of climate science, except for instead of molesting children, he has molested and tortured data,” Simberg wrote. Later, Steyn referenced Simberg’s article in a piece in National Review, calling Mann’s research “fraudulent.”

Mann argued that he had lost grant funding as a result of the blog posts. The writers countered during the trial that they were stating opinions and that Mann became one of the world’s most well-known climate scientists in the years after their comments.

On Thursday, the jury sided with Mann and awarded him $1 million from Steyn, $1,000 from Simberg and $2 in compensatory damages ($1 from each writer).

During the trial, Steyn represented himself, but said through his manager Melissa Howes that he would be appealing the $1 million award in punitive damages, saying it would have to face “due process scrutiny.” Simberg’s attorney, Mark DeLaquil, also said his client would appeal the jury’s decision.

Many scientists have followed Mann’s case for years as misinformation about climate change has grown on social media platforms. Some say they hope the verdict will force critics to think twice before they say something damaging.

“I hope people think twice before they lie and defame scientists,” Kate Cell of Union of Concerned Scientists — a nonprofit science advocacy organization — said. Her work as senior climate campaign manager includes tracking misinformation related to climate change. “We are so far outside the bounds of a civil conversation about facts that I hope this verdict can help us find our way back.”

Mann also said Thursday that he plans to appeal a 2021 decision reached in D.C. Superior Court that held National Review and the Competitive Enterprise Institute not liable for defamation.

“We think it was wrongly decided,” Mann said. “They’re next.”

The Associated Press contributed to this report.