Penn professor Michael Mann has reached an agreement with the National Review that releases him from paying the company’s remaining legal fees from his defamation case in exchange for dropping ongoing litigation against the magazine.
The agreement marks the latest development in Mann's 2024 suit against bloggers Rand Simberg and Mark Steyn. Last spring, a District of Columbia judge ordered Mann to pay more than $530,000 in legal fees to NRO after the defendants filed a motion under D.C.’s Anti-SLAPP Act, which is designed to protect individuals exercising free speech from frivolous defamation lawsuits.
In a statement published on his website, Mann wrote that, “we have now reached an agreement with NRO wherein we will drop our appeal (whose fate is uncertain) of these decisions in return for NRO dropping their request for costs.”
“While this constitutes the end of a portion of this complex litigation, we would emphasize once again the key points: The jury’s verdict—finding that the posts hosted by NRO and CEI were false, defamatory, and published with malice—stands,” Mann wrote in a statement to The Daily Pennsylvanian.
Mann was awarded more than $1 million in a defamation lawsuit settled in February 2024. The 2012 lawsuit argued that Steyn, a contributor to NRO, and Simberg, a former adjunct fellow at the Competitive Enterprise Institute, defamed Mann through blog posts that challenged his climate research as fraudulent and accused him of misconduct.
In January 2025, Superior Court Judge Alfred S. Irving ordered Mann to pay a portion of NRO’s legal fees.
Two months later, Irving reduced the damages owed by Steyn to $5,000, calling the original jury award “grossly excessive.” He sanctioned Mann for providing misleading information on alleged grant losses during the trial.
Mann's legal team intended to challenge the accusations of bad-faith reporting of his grants. In a statement to X, Mann wrote that, “I am confident neither I nor my lawyers did anything wrong during the trial.”
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While Mann initially appealed Irving's decision, the agreement with NRO means his appeal will be dropped.
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Staff reporter Ashley Wang covers student health and wellness and can be reached at wang@thedp.com. At Penn, she studies philosophy, politics, and economics.
