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The climate scientist Michael Mann on Thursday won his defamation lawsuit against Rand Simberg, a former adjunct scholar at the Competitive Enterprise Institute, and Mark Steyn, a contributor to National Review.

The trial transported observers back to 2012, the heyday of the blogosphere and an era of rancorous polemics over the existence of global warming, what the psychology researcher and climate misinformation blogger John Cook called “a feral time.”

The six-member jury announced its unanimous verdict after a four-week trial in District of Columbia Superior Court and one full day of deliberation. They found both Mr. Simberg and Mr. Steyn guilty of defaming Dr. Mann with multiple false statements and awarded the scientist $1 in compensatory damages from each writer.

The jury also found the writers had made their statements with “maliciousness, spite, ill will, vengeance or deliberate intent to harm,” and levied punitive damages of $1,000 against Mr. Simberg and $1 million against Mr. Steyn in order to deter others from doing the same.

“This is a victory for science and it’s a victory for scientists,” Dr. Mann said.

In 2012, Mr. Simberg and Mr. Steyn drew parallels between controversy over Dr. Mann’s research and the scandal around Jerry Sandusky, the former football coach at Pennsylvania State University who was convicted of sexually assaulting children. Dr. Mann was a professor at Penn State at the time.