Neither Doom, Nor Denial

An Interview with Climate Scientist Michael Mann, Director of the PCSSM

Vanessa Schipani
Vanessa Schipani

Vanessa Schipani is a PhD Candidate in Philosophy at Penn and prior to the PhD was a journalist for over 10 years, including for

Michael Mann is an adherent of the notion that out of crisis can come opportunity. When his research on global warming led to death threats, he saw it as a chance to push back against deniers and improve the public debate surrounding human-caused climate change. But Mann, the Director of the new Penn Center for Science, Sustainability and the Media (PCSSM), rejects doomism just as much as he spurns denialism. There is still a path forward, he says, where we can avoid catastrophic climate change and create a more equitable and just world in the process.

I first met Mann while vetting the claims of U.S. politicians as the science writer for, a nonpartisan nonprofit based at the Annenberg Public Policy Center. For my very first article for the outlet, Mann walked me through why climate change is not a pseudoscientific theory, contrary to senator Ted Cruz’s claim that it could “never…be disproven.” My background in philosophy helped me catch the falsehood. Still, I was surprised to find allusions to the ideas of Karl Popper in the speech of a politician. But it was familiar terrain for Mann, who had seen the full spectrum of denialist tactics in his career.

That was back in 2016, then the hottest year on record, which is now tied with 2020. More recently, I sat down with Mann, who is also a Presidential Distinguished Professor in the Department of Earth and Environmental Science with a secondary appointment in the Annenberg School for Communication, to talk about the PCSSM, the future of climate policy, a new book he’s writing and how he got into climate communication in the first place. The interview has been condensed and edited for clarity.

How did you get interested in climate communication?

I was sort of thrown into the lion’s den. Back in the late 1990s, my coauthors and I published the now iconic hockey stick curve, a graph that covers a thousand years of global temperature change and links rising temperatures over the 20th century to human activity. It became a very potent symbol and was attacked by climate change deniers. I found myself at the center of personal attacks that were aimed at discrediting me, as the lead author of those studies.

And even death threats, right?

Death threats and demands for me to be fired. Threats against my family even. An envelope of white powder was sent to me at Penn State, where I was a professor before coming to Penn. It was a very uncomfortable position to be in as a scientist. Nothing in your training prepares you to deal with bad faith attacks. It’s one thing to deal with scientific criticism – that’s part of the self-correcting machinery of science. But personal attacks intended to silence you have no legitimate place in science. As I found out, they are part of the ground rules of modern politics. So, I had to decide: Was I going to withdraw into my laboratory? Or was I going to fight back? I chose the latter and it set me on a journey that would ultimately lead me to greater engagement in the public discourse surrounding human-caused climate change.

In another interview you mentioned that you were initially “reluctant” to leave the laboratory for the public space. Why?

It’s just not what I signed up for. It’s not why I pursued degrees in applied math, physics and geology. Spending time replying to attacks takes away from your time to do science. But the attacks opened my eyes to the fact that malevolent forces are working to discredit the science that informs policy. Over time I’ve grown to embrace this role. I feel privileged to be in a position to inform this fundamentally important conversation, though it is miles away from where I started and what I thought I was going to be doing with my life.

The philosopher in me has to ask – was any part of your reluctance back then motivated by the trope of the scientist as value-free, and, therefore, as needing to stay out of the fray of politics, a value-laden world?

There is this trope, as you say, that the scientist should be impartial and that somehow also means we shouldn’t express our views about the implications of our work. This idea that we leave our citizenship at the laboratory door, it’s a crazy idea.

But would you say that, perhaps in part because of the climate issue, this trope of scientists has dissipated? Many scientists now seem to think they can stand up for science in the politics arena, but also aim for objectivity in their research. They’re not incompatible actions.

Yes, it’s been a long battle. I would say this is possible because so many before me created the space that I was able to move in to. In turn, myself and other climate scientist communicators of my generation have hopefully created even more space for the next generation.

Let’s talk about the PCSSM. The center’s main goal is to improve the public conversation surrounding issues of sustainability and climate. What does improvement look like to you?

Typically scientists who come into this think the problem is that we just haven’t explained the science clearly enough. If we can just get better at explaining, then of course the politicians will hear us. I learned the hard way that that’s not how it works. Yes, understanding the science is critical – we have to be able to inform people accurately about the risks that are involved and we can only do that with a fundamental understanding of the climate. But we have so much to learn from communication experts, psychologists and sociologists. We have to work together with these experts to improve discourse about science-related issues. One of the things that drew me to Penn, and this joint appointment with the Annenberg School of Communication, was the opportunity to work with people like Kathleen Hall Jamieson, who has been at the vanguard of research on science communication. It’s a dream come true.

Experts in the ‘science of science communication,’ like Jamieson, argue that science communication is an ‘environment’ that involves interchange among various actors, not just the top-down transmission of information from experts and journalists to the public. The name of the center includes the term ‘the media.’ Will the center concentrate only on journalistic communication?

I’m glad you asked that. Think of ‘media’ as interpreted very broadly, including social media, including the arts – everybody who’s involved in science communication in some way, so definitely broader than journalism. Journalism is a big part of it, but it’s definitely the larger ecosystem of science communication that we’re concerned with.

What about the term ‘sustainability’ in the title of the center? The ad for the post doc positions affiliated with the center mentioned that you’re looking for people who are interested in climate communication, but with links to other areas of science denialism, including vaccines and Covid-19. How do these issues get folded into concerns about sustainability?

You’ll notice that the term ‘climate’ isn’t actually in the title of the center. That tells you something. Yes, a lot of what we’re concerning ourselves with is going to be climate-related because that’s arguably the defining sustainability challenge of our time. But one can interpret sustainability quite broadly – in fact, more broadly than purely environmental sustainability, including societal stability and issues of justice and equality. I was pretty careful in choosing a name for this center that isn’t exclusionary and allows for all of these broader conversations.

Recently, there have been some major changes in the climate policy arena, but it’s still not enough. The next ten years are crucial. Where do you think we’ll be when it comes to combating climate change ten years from now?

I’m optimistic. We’re in this really interesting historical moment, where the United States and Australia have recently signed into law major climate legislation. Because we’re making real progress now, we’ll look back and see this as a turning point, I think. So, ten years from now, there will still be challenges left, but we’ll have a tailwind at our back. By the way, this is going to create an interesting conversation with Malcom Turnbull, the former Prime Minister of Australia, who will be our inaugural speaker at the center on September 13.

I heard you’re writing a new book. What’s it about? 

The title of the book will be The Benevolent Moment and it’s about the lessons we can learn from past climates to help us with the current climate crisis. It was an opportunity, frankly, to get back to the science. I had written a couple books that were about the politics of climate change, and I wanted to get back to my scientific roots.

I think one of the most interesting things that I wrote about when I was at was that the climatic period that we’re in right now, the Holocene, is unusually stable when it comes to geological history — so stable that it permitted civilization to develop as it has.

That’s right, and yet at the same time, while global temperatures haven’t changed much since the end of the last ice age, there have been some regional changes, like the Middle East became drier and drier. It was actually aridification in Mesopotamia that drove the development of irrigation. So, climatic changes have also, to some extent, forced us to develop some of the infrastructure of modern civilization.

A silver lining of sorts? That makes me think to ask, is there an anti-doomism message in the book? You’ve spoken elsewhere that climate doomists are just as wrong-headed as deniers.

Fundamentally, anything that threatens to take global temperature outside of the range of the past ten thousand years is a threat. But looking at some of the distant past periods does end up pushing back against doomism. Take the PETM [Paleocene-Eocene Thermal Maximum], a period 55 to 56 million years ago when there was a sudden warming event. There’s been speculation that it was caused by a massive release of methane, but if you study the science closely, it tells us that this is not the case. So, when some of the doomists say it’s too late, the methane is leaking out of the arctic permafrost and we should just enjoy the planet while it’s still livable, that’s based on an erroneous interpretation of the paleoclimate record. This means that we can prevent catastrophic consequences through concerted climate action, but at the same time, if we do nothing, if we continue with business as usual and burn every fossil fuel that we can get ahold of, then the record tells us pretty soon you do start to run up against fundamental threats to the stability of civilization. So, the truth is in between the extremes, the doomists and the deniers.

The truth always is somewhere in the middle, isn’t it?

Yes, it is. As the late climate scientist Steve Schneider once said, when it comes to climate change, the ‘end of the world’ and ‘good for us’ are the two least likely outcomes.