Climate Scientist Michael Mann Wins Defamation Case

17:17 minutes

A man looking cheerful behind a microphone
Michael E. Mann speaking at Pennsylvania State University. Credit: Michael Ferguson, CC BY-NC-SA 2.0

Climate scientist Dr. Michael Mann won a defamation lawsuit against two conservative writers last week.

The verdict was 12 years in the making. In 2012 writers Rand Simberg and Mark Steyn accused Mann of manipulating his data related to his famous 1998 “hockey stick” graph, which depicts rising global temperatures after the industrial revolution. Simberg compared him to former Penn State football coach and convicted child sex abuser Jerry Sandusky in a blog post for a libertarian think tank. Steyn later referenced Simberg’s article in a National Review piece, calling Mann’s work “fraudulent.”

Reviews by Penn State (Mann’s home institution at the time) and the National Science Foundation, found no scientific wrongdoing. And in fact the iconic graph has since been supported by numerous studies.

What does this ruling signal about the public’s understanding of climate change research? And the limitations of free speech?

Ira talks with Dr. Michael Mann, professor of Earth & environmental science at the University of Pennsylvania and author of Our Fragile Moment: How Lessons from Earth’s Past Can Help Us Survive the Climate Crisis.

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Segment Guests

Michael Mann

Dr. Michael Mann is the author of Our Fragile Moment: How Lessons from Earth’s Past Can Help Us Survive the Climate Crisis, a professor of Earth & Environmental Science, and the Director of the Penn Center for Science, Sustainability and the Media at the University of Pennsylvania in Philadelphia, PA.

Segment Transcript

IRA FLATOW: This is Science Friday. I’m Ira Flatow.

Last week, climate scientist Michael Mann won a defamation lawsuit against two conservative writers. The verdict was 12 years in the making. In 2012, bloggers Rand Simberg and Mark Steyn accused Mann of manipulating his data, comparing his research methods to Penn State football coach Jerry Sandusky, convicted child molester.

Reviews by Penn State and the National Science Foundation found no wrongdoing. And in fact, his iconic 1998 “hockey stick paper,” showing rising global temperatures after the Industrial Revolution, that paper has since been supported by numerous studies.

Observers are calling it a landmark ruling, a victory for science. So what does this ruling signal about the public’s understanding of climate change research and a scientist’s right to speak the truth without fear of attack? Joining me to talk about those questions is Dr. Michael Mann, professor of Earth and environmental science at the University of Pennsylvania, and author of the new book, Our Fragile Moment. He is based in Philadelphia.

Dr. Mann, always good to have you back on Science Friday.

MICHAEL MANN: Thanks, Ira. Always great to be with you.

IRA FLATOW: Nice to have you. Michael, some history first, please. What was the nature of the blogs? And what did they say? And take it from there.

MICHAEL MANN: Yeah, I think you summarized it pretty well there. This was back in July 2012. It was after the report on the Sandusky affair had just been published. And they decided to exploit that by taking a swipe at me, literally comparing me to Jerry Sandusky– of course, the convicted child predator– accusing me of molesting and torturing data and making accusations of scientific fraud.

And it’s one thing to criticize scientists– criticism, skepticism, done in good faith, those are constructive and important things in science. But making false accusations against scientists as part of an ideological agenda to discredit them and their research, that crosses a line. And that’s what we decided. We couldn’t let that stand.

IRA FLATOW: And when did you decide it? Not immediately, right?

MICHAEL MANN: No. Within, I believe it was, a couple of weeks. Actually, a good friend of mine, who is a great science communicator, Phil Plait, of the Bad Astronomy Blog, sent me an email that alerted me to these defamatory articles. And he actually suggested, you might want to contact a lawyer. And that’s what I did.

And we asked for a retraction and an apology. They refused to do that. And so that’s what led us to where we are now, 12 years later.

IRA FLATOW: And 12 years– were you discouraged it took 12 years as you’re waiting?

MICHAEL MANN: Well, you know what they say about justice delayed.


MICHAEL MANN: So it was a long time to have to wait to have our day in court. But again, there were important principles at work here. We couldn’t let it slide, even though they appealed multiple times, all the way to the Supreme Court. We stuck with it because it was too important to let it go.

We felt we needed to send a message, really, to the scientific community that it’s OK to speak out about the implications of your science. And it’s not OK when people try to defame you simply for speaking about your science and its implications.

IRA FLATOW: And what was the award that you got?

MICHAEL MANN: Well, we got compensatory damages of $1 per defendant. I’ve already spent that at Starbucks. Obviously, a small award. It was really a nominal award. And in the end, I guess the jury decided that I’d gone on. I had been pretty successful. So it wasn’t obvious that I had been damaged in any fundamental way.

I would argue that there was an emotional toll that it took for me and my family– those sorts of comparisons and the way it made us feel in our community. But more importantly, they felt that a message did need to be sent. And that’s what the punitive damages are, to make a statement, that this is not acceptable and there should be a huge penalty. And they awarded us over $1 million in punitive damages.

IRA FLATOW: That is really interesting because I know these cases are really hard to win because you have to find enough evidence that there’s malicious intent, right?

MICHAEL MANN: Yeah, that’s right. I mean, because I’m considered a public figure, it’s not enough to show that the statements were false. You have to be able to show that there was actual malice. Which means that the defendants either knew that the statements were false or they acted with reckless disregard for the truth. That’s the critical phrase that comes out of the New York Times versus Solomon case many years ago.

And so the jury found that they did, indeed, act with reckless disregard for the truth, given that there were multiple reports, including the National Science Foundation’s Inspector General, that had vindicated us of any misconduct and wrongdoing. And they obviously ignored them– chose to ignore them. That’s what led us to where we are today and towards a unanimous jury decision in our favor.

IRA FLATOW: Might we see more cases of scientists who have been afraid to speak out now come forward, do you think?

MICHAEL MANN: I hope so. Because I think one of the reasons that our detractors– and I’ve been a target of climate deniers, of polluters and conservative interest groups– for decades because of the hockey stick curve that we published decades ago that became this iconic symbol in the climate debate. And so my worry has always been that the attacks on me were meant to send a message especially to younger scientists, who might think about speaking truth to power, speaking out about the policy or societal implications of their research.

My fear has always been that the attacks against me were an effort to chill the discourse, to basically scare other scientists, who might think of leaving the laboratory and speaking out about the implications of their science. And that’s why I felt this case was always bigger than me. It wasn’t just about my reputation. It was really about the ability of scientists to speak truthfully and openly to the public and to policymakers without fears of these sorts of reprisals.

IRA FLATOW: It’s been 12 years. And in those 12 years, a lot has changed. We don’t have just blogging now. We have TikTok, Twitter, YouTube videos. Have attacks on scientists changed with the times, too, albeit in different formats?

MICHAEL MANN: Yeah. I mean, that’s right. It’s remarkable how much things have changed in the 12 years since we filed this suit. Social media has become just a toxic environment, in many respects. Twitter– a lot of my fellow scientists have chosen to leave Twitter because of the toxic atmosphere under Elon Musk’s ownership of the medium.

And scientists are regularly subject to attacks. And it’s not just climate scientists now. It’s public health scientists, like Anthony Fauci or my good friend Peter Hotez, who are also attacked for ideological reasons because their science about vaccines and about COVID-19 is inconvenient to vaccine deniers.

And so there’s this sort of cesspool of science denialism, of anti-science, that exists, that is very widespread on social media. And that’s, of course– when you’re dealing with anonymous trolls, it’s very difficult. There’s no way of penalizing their bad acts.

But what I do hope– that this successful lawsuit will send a message to prominent media outlets who have promoted attacks– defamatory attacks– against scientists, against climate scientists, against public health scientists. I hope that this does send a message to them. It does draw a line in the sand, that if you engage in defamatory attacks against scientists in an ideologically-driven attempt to discredit their science, there will be repercussions. There will be legal repercussions.

IRA FLATOW: Despite all of this– speaking of climate science– I’ve been observing that recent polls show the public has reversed its opinion on climate change. Polls that used to show skepticism are now showing belief. Do you have a reason for that?

MICHAEL MANN: Yeah. I think the simplest reason is, look out your window. Read your newspaper headlines. Watch the television news. The impacts of climate change are now literally playing out in real time. We can see it with our own two eyes. We know people– if not ourselves– family members, friends, who have been subjected to unprecedented flooding events, wildfires, homes destroyed. It’s gotten real for people.

And what that means is that the public largely gets it. Climate change is real. It’s human caused. We wouldn’t be seeing these unprecedented impacts if not for our continued burning of fossil fuels. And so the polluters have changed their tactics.

In fact, my previous book, The New Climate War, was about this shift in tactics, away from denial to other ways of undermining climate action– deflection and division– and even doom mongering. If they can convince us it’s too late to do anything about the problem, it potentially leads us down that same path of inaction.

And so we have to look out for these new tactics that are being used to prevent the needed transition from fossil fuels to renewable energy. It’s less denial now, and it’s much more about these other more subtle, but nonetheless very effective tactics.

IRA FLATOW: That’s interesting you talk about denial or deflection. I have noticed, in the past 12 years, it used to be that journalists have never, ever connected anything to climate change– any of these tragic events, any of the weather. They never ever say, it might be climate change. The rising sea level, Florida is going underwater– they don’t ever talk about it. But now, it seems like they may be doing a better job at covering climate science. Would you agree?

MICHAEL MANN: I do agree. I think there’s been an effort– actually, it’s been, I would say, a partnership, really, between the scientific community and the journalistic community because we are natural allies. We’re both interested in truth, either in determining truth– that’s what science is or communicating truth to the public.

And so I’ve always felt that that was a natural alliance between journalism and science. And I think we have seen efforts for these two communities to work together to improve the quality of climate communication.

And there’s been a lot of work in finding ways to communicate the impacts of climate change in a way that rings true to people, that reaches people where they are, to make it clear that this isn’t just about disappearing ice in the Arctic and polar bears. It’s about the unprecedented extreme weather events that we’re seeing.

Here in Philadelphia, where I live, we had the worst air quality in the world for several days this summer because of the Canadian wildfire smoke that was making its way down here. I think that there has been a real effort to find narratives, to find ways to communicate the fact that not only is climate change real, we’re feeling it in a visceral way now.

IRA FLATOW: Yeah. Getting back to your court case for a moment and some of the possible implications– you touched on this before, saying that scientists are known to be critical of their colleagues’ work. They rebut or question their findings. But we shouldn’t be concerned that scientists might be worried about criticizing other scientists’ work because of possible defamation territory itself.

MICHAEL MANN: Yeah, I’m glad you asked that, Ira, because it’s such an important distinction. I mean, good faith criticism is one of the driving forces in science. The great Carl Sagan described the self-correcting machinery of science. And peer review– the formal criticism that is in place in the peer review system, when you present your work at meetings, that give and take, that is part of the self-correcting machinery of science. And it’s essential and it has to be preserved.

And the key thing there is that it’s in good faith. That’s good faith criticism. It’s criticism that’s based on logical reasoning, arguments about deficiencies or flaws in a modeling approach or in the data set that’s used. That’s all fair game. That’s legitimate scientific discourse, that sort of criticism.

But there is a distinction, a very important distinction, between that good faith criticism and the bad faith attacks that are intended not to elucidate truth or identify legitimate flaws or limitations of scientific findings, but are intended to discredit the scientists, that are intended to discredit science in the eyes of the public. And I think that the jury saw through the smoke and mirrors of the other side in this trial and recognized that critical distinction.

I don’t care if you don’t like somebody research. It doesn’t give you license to accuse them of fraud and compare them to a child molester, which is what these two defendants did.

IRA FLATOW: This is Science Friday, from WNYC Studios.

In case you’re just joining us, I’m talking with climate scientist Dr. Michael Mann about his victory in a recent defamation case.

What’s your message to other scientists? They’re watching what you’ve been going through. They might want to opt out of a controversy or being in the public spotlight. What do you make of that argument that scientists should just keep their heads down and focus on the science?

MICHAEL MANN: Well, thanks again for that question, Ira. Because that’s why I fought on for 12 years. And I’ve been fighting my whole career. I would have been perfectly happy if they had left me alone in the computer lab, doing what I love doing, which is constructing models and analyzing data sets. That’s why I went into science in the first place. That’s why I double majored in applied math and physics and went off to study theoretical physics in graduate school– because I love doing science.

But when the findings of my science– again, when I became a target because of our findings– I realized that there was another role, an opportunity to play, and it was incumbent upon me to play, which was to defend not just my science, but, really, I felt like I was defending science itself against bad faith attacks.

And I also felt that I had to prevail in this battle. Because if I didn’t, it would send the wrong message to young scientists. It would say, hey, if you stick your head up, if you speak out, speak truth to power, then they’re going to come after you and they’re going to destroy you. I couldn’t allow them to be successful in that venture.

And so I hope that this very important finding, the million-dollar damages that were awarded, does send a message to my fellow scientists that, hey, look, the system does have our back. You have recourse if you are subject to bad faith attacks that are intended to discredit you in the way that our attackers came after me. That you have recourse in the form of the law, and you have your fellow scientists who will stand by you. And the most important thing to me in all of this has been the support that I’ve gotten from my fellow scientists through the whole process.

IRA FLATOW: I can’t let you go without talking a bit about science and your most recent book, Our Fragile Moment. Briefly, in the minute we have left, what is our fragile moment?

MICHAEL MANN: In a minute and a half, I’ll try to summarize 4 billion-plus years.


That’s what I do. I look at the collective lessons that we can learn from all of Earth history, going back to Earth’s beginnings more than 4 billion years ago. And in the end, to summarize it very simply, what the evidence points to is that there is great urgency now. We are at a fragile moment when it comes to human-caused warming, human-caused climate change. There is urgency, but there is agency. It’s not too late for us to take the actions that are necessary to avert disaster.

IRA FLATOW: Yeah, we had you on when you talked about the book, and you were hopeful. I’m glad to hear you’re still hopeful. Thank you for your work, Dr. Mann.

MICHAEL MANN: Oh, thank you, Ira. Always a pleasure.

IRA FLATOW: Dr. Michael Mann, professor of Earth and environmental science at the University of Pennsylvania, and author of Our Fragile Moment.

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