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Climate Change

Podcast: 5 climate scientists share their reasons for hope

Stereo Chemistry explores how early-career chemists are confronting a changing climate

by Kerri Jansen
February 10, 2020 | A version of this story appeared in Volume 98, Issue 6

Credit: Ink Drop/Shutterstock


Climate change is on the public’s mind, thanks in no small part to the efforts of Swedish activist Greta Thunberg and protests and rallies involving young people around the world. In the latest episode of Stereo Chemistry, host Kerri Jansen talks with early-career researchers developing the tools and knowledge we’ll need to thrive in a changing climate. These scientists are part of a generation that will experience the effects of climate change throughout their lifetimes. They share what drew them to climate science and what keeps them motivated when the questions—and the obstacles—are so vast.

Read C&EN’s special issue on climate change adaptation at

Subscribe to Stereo Chemistry now on Apple Podcasts, Google Play, or Spotify.

The following is the script for the podcast. We have edited the interviews within for length and clarity.

Diana Dumit: My partner says that I’m a pessimist when it comes to, like, the future of the world.

Kerri Jansen: This is the episode of Stereo Chemistry where we talk about climate change.

The voice you just heard—the purported pessimist—is Diana Dumit, a grad student at MIT. She’s one of the many chemists whose work intersects the impacts of climate change, the shifting weather patterns and gradual warming of our planet resulting from us humans dumping way too much of greenhouse gases like CO2 into the atmosphere.

The climate crisis has been called the defining issue of our time. And we are bombarded constantly with reminders of its expected impacts—many of which are already starting to happen. Extreme weather, changes to water resources, floods, fires, threats of extinction. When faced with all of that, it’s understandable that someone might feel pessimistic. Which is why what Diana said next surprised me.

Kerri (in interview): I mean, would you call yourself a pessimist?

Diana Dumit: I don’t think I’m a pessimist. I’m more of like, I’m optimistic that humans are innately good people, and we just want to survive. So I’m optimistic, especially for, like, the youth, because I see a lot of young people really thinking about all these things. I think at the end of the day, if we have the correct tools and we have the knowledge, then we’re going to be okay. But we need to act fast.

Kerri (in studio): In this episode, we’ll share the stories of young researchers like Diana who are dedicated to tackling various sides of the climate change problem, developing those tools and knowledge that will enable humans to survive and thrive in a climate that is already changing. As early-career scientists, these five researchers are part of a generation that will experience the impacts of climate change in their lifetimes. And yet, what I heard repeatedly was a sense of optimism. We’ll hear their reasons for hope, what drew them to these huge challenges, and what keeps them motivated when the questions—and the obstacles—are so vast.

I’m Kerri Jansen.

(crowd clapping)

Iain Armitage: I would like to say happy birthday to Greta Thunberg! (crowd cheers)

Kerri: There’s no question that climate change activism has become a global movement. Galvanized by Greta Thunberg, the 17-year-old Swedish environmental activist, young people are pushing climate change to new levels of public awareness, with powerful protest events around the world, like the one you just heard, spearheaded by Jane Fonda, in Washington DC. On the website run by Fonda’s group, there is a pledge to, quote, “answer the alarm sounded by young people like Greta Thunberg and bring the climate emergency to the axis of power.”

Donna Chavis: We’re all climate activists together! (crowd cheering)

Kerri: Here at Stereo Chemistry, we’ve taken note of this movement and its call for drastic change. We wanted to hear how young people—including early-career chemists—are thinking about these issues. Before I set about interviewing chemists, though, I consulted with my colleague, Gina Vitale. She’s a production editor here at C&EN who recently wrote a story about climate change in the classroom, which is part of a bigger package we just released on climate adaptation. I’ve asked Gina to join us today.

Gina Vitale: Hi Kerri.

Kerri: Hi Gina. Can you tell us a bit about your conversations with students?

Gina: So my story is about climate change adaptation in the context of education—the idea is the climate is already changing, so how are students learning about it? And what solutions are they coming up with for how to adapt to what’s already happening? I talked to some students who are interested in preserving infrastructure.

Kerri: Oh, so like roads and bridges, that sort of thing?

Gina: Yeah, and storm water drainage systems and other structures like commercial buildings. They want to make sure these structures can withstand changing weather patterns and extreme events that are associated with climate change. I was really impressed with how passionate they are.

Kerri: That’s definitely something I got from the chemists I interviewed too. You can read Gina’s article—and more coverage of climate change adaptation—in the Feb. 10 issue of C&EN. We’ll put a link to it in the description for this episode.

It’s undeniable that the passion of young people is making an impact, and, as Diana said at the top of the episode, many find inspiration in what they’re doing—including scientists who are beginning to focus their scientific careers.

Lyssa Freese uses computer modeling to study the impact of energy policies on pollution levels.
Lyssa Freese uses computer modeling to study the impact of energy policies on pollution levels.

Elisabeth Freese: I always say that kind of my generation grouping of people is in this interesting position where we’re not quite in the youth movements, because we’re not teenagers. But we’re also not part of kind of that era that’s not going to necessarily have to live with these impacts.

Kerri: Lyssa Freese is a grad student at MIT, studying atmospheric chemistry.

Elisabeth Freese: We’re caught in between, and I feel like these youth movements are even more important to me because it’s like, I’m going to be in the shoes of leadership 10 years before they’re able to. And so they’re calling on leaders right now to make changes, and soon I’m going to be in that stage of my life.

Kerri (in interview): Do you feel a lot of pressure working in this area and knowing that people will be holding you and, you know, older generations accountable for these sorts of things?

Elisabeth Freese: External pressure? Not really. I think that rather than feeling nervous that someone will hold me accountable, I think it’s honestly very empowering to feel that. And I think that it’s really great to know that the work that I do and that I love could be something that could improve the state of the United States, the world, in x number of years.

Kerri (in studio): Lyssa works on air pollution and energy policy. She uses modeling to see the impact of various policy changes on particulate levels in various regions. A better understanding of those nuances, she says, could help inform better policy decisions.

Gina: OK, particulates aren’t great—they are air pollution, and they’re bad for us to breathe in, but they aren’t the primary cause of climate change, right?

Kerri: Right. But as Lyssa explained, the production of particulates and the production of CO2 are closely linked as many energy-generating operations produce both.

Elisabeth Freese: The main thing is that the source of CO2 and the source of these pollutants is the same thing. So when you’re tackling one, you’re going to tackle the other as well.

Kerri: Lyssa’s background is in health policy—not atmospheric chemistry. But while working abroad in Beijing, she gained an awareness of the links between public health, air chemistry, and the environment.

Elisabeth Freese: After I graduated college, I moved to Beijing to work with a think tank over there. And so I experienced pollution in Beijing for five months. And that was when I was like, this is hands down the most shocking and interesting health policy issue going on. And then that was immediately when I realized that it was not just a health issue, it was an environmental issue. And as I began to contemplate doing a graduate degree, I knew that climate had to be an aspect of it.

Kerri: For those of you who haven’t experienced air pollution in Beijing first hand, the region has struggled through recurring bouts of heavy brown haze, prompting many residents to don masks as protection against the health impacts of polluted air.

Lyssa saw an opportunity in tying together chemistry and policy to look at how current policies could be improved. And considering that climate change can be a heated topic in some places, she saw an advantage in focusing on the issue of air pollution instead—an issue everyone could get behind, because it directly affects their health.

Elisabeth Freese: And at the same time, you’re also getting huge climate benefits from the same thing. I think that the main issue with climate change, and storytelling around climate change, is the fact that only recently have we realized that telling people that polar bears and ice caps are melting is not going to get much action. And so people are like, Oh, well, we have to relate this to humans in our own country. And what do people care the most about? I mean, they care about their financial means and their health. I think those are some of the top two things that people on a day-to-day basis really focus on.

Gina: Can confirm. My health and my financial stability are super important to me. There’s definitely something to be said for not tricking people, but thinking about where that resistance might be coming from and guiding them toward changes that can benefit the environment. Making those changes a little easier to swallow.

Kerri: Yeah. And this is something I also discussed with Rich Cottrell, who studies food systems—how and where we produce our food, under what conditions people will adopt new foods, that sort of thing. What does that have to do with climate change? Well, experts predict that as weather patterns change, water levels rise, and so on, it will be more and more difficult to grow and produce crops and foods in the ways that we’re used to. Rich’s goal is to help manage the change that could be on the way.

Richard Cottrell: You know, it’s really hard to understand why people eat the things they do, and changing those behaviors are really hard. And we have a rough idea of what people should be eating more of, but going from that knowledge to actually changing how people shop and buy in restaurants, that’s a huge, huge gap. There’s some ideas out there, but there’s no wide-scale, coherent plan as to how to influence that or why we should influence that.

Kerri: Rich is starting a postdoc at UC Santa Barbara investigating the plausibility of cell-based seafood.

Gina: Oh, like the clean meat we’ve written about in C&EN.

Kerri: It’s the same kind of idea, yeah. Clean meat means meat grown in a lab or in a factory from animal cells. It avoids the need to harvest live animals, and it reduces the energy used to raise them and the greenhouse gases emitted in the process.

Gina: So then cell-based seafood might be something like tuna grown from cells rather than harvested from a fish farm or caught from the sea, where overfishing is a real concern.

Kerri: Right. But as Rich notes, just because we might be able to do this with chemistry, doesn’t mean the problem is solved. There are still a lot of questions related to economics and access, in addition to the environmental issues. For him, those questions are the top concern.

Rich Cottrell studies food systems and is beginning a new project to evaluate the plausibility of cell-based seafood.
Credit: Courtesy of Rich Cottrell
Rich Cottrell studies food systems and is beginning a new project to evaluate the plausibility of cell-based seafood.

Richard Cottrell: In terms of our resource efficiency, we’ve improved so much. And I don’t think it’s about whether we can adapt as a species. I think it’s about how evenly that adaptation can occur. And I think that’s where the importance really lies. And I think the thing that frightens me is, we will adapt in terms of total food production. But the reason that you’ve got hungry people in this world right now is not that we don’t have enough food; it’s actually that those people cannot access that food, whether that’s for economics, or whether that’s for physical access, you know. And there’s a whole bunch of reasons that are also the drivers behind that access. Attacking them is really difficult, I think.

Gina: That’s something that’s kind of intimidating to think about, how all of these changes all over the world are so interconnected. And, you know, climate change is a global issue. Adapting to it ought to be a global issue, too, not just something for the wealthiest nations.

Kerri: And that’s a concern that was echoed by many of the scientists I spoke with. Diana at MIT, the optimist from the beginning of the episode, is doing work related to ocean chemistry. Oceans are challenging to study because they’re so complex.

Diana Dumit studies the impact of ocean microbes on water chemistry. Here, she’s in the control room of a water-sampling research vessel.
Credit: Courtesy of Diana Dumit
Diana Dumit studies the impact of ocean microbes on water chemistry. Here, she’s in the control room of a water-sampling research vessel.

Diana Dumit: I think that’s the hard thing with biogeochemistry is the way that all of these nutrients are intertwined.

Kerri: Diana is studying how microbes interact with nitrogen, a nutrient, in certain areas of the ocean. Climate change has the potential to reshape how nitrogen cycles through the environment, including in the ocean.

Gina: So what exactly are these microbes up to with all that nitrogen?

Kerri: So right now, Diana is focused on microbes that live in areas of low dissolved oxygen in the ocean. There are a handful of these low-oxygen zones scattered around the world, plus some seasonal ones, and they’re expected to expand as oceans warm. Reduced oxygen can stress or even kill marine organisms, or shut them out of certain habitats. And those changes in water chemistry can disrupt other parts of the ecosystem. For example, some microbes in these low-oxygen zones survive by sucking up nitrogen-based nutrient molecules from the environment—ammonium, for example. They convert those molecules to nitrogen gas, which they release and which most other marine species can’t use. The whole process is called denitrification.

Gina: So as these low-oxygen areas expand because of climate change, these microbes could be taking more and more nitrogen out of the environment, leaving less for other species.


Kerri: Right. And some of these microbes produce nitrous oxide instead, which is a greenhouse gas that can make the problem even worse. Scientists don’t yet know exactly what the impacts will be on the planet’s nitrogen budget.

Diana Dumit: At the end of the day, we’re like, trying to understand things that will have maybe not a direct impact, but in a way will help us understand the changes we’re going through, as the world, as a society. It’s also kind of like, directly related to where I was born. So I was born in Dominican Republic. And I know, for example, that the small islands and communities are going to feel the climate change impacts and global warming changes—like sea level rise and hurricanes—firsthand. And so I guess, studying this, in a way, maybe makes me feel like I’m doing something for my country. And not only for my country, but for the world. Everyone deserves to know why the climate is changing, why everything is warming, why things are different. Because it’s not something that only affects the scientists. It’s something that affects everyone.

Kerri: Diana says she’d like to use her position as a scientist to advocate for people who stand to be most affected by the changing climate—including those in the Dominican Republic.

Diana Dumit: I was born there, and I lived there, and I know what’s going on. I can go and talk to them without, you know, this sense of superiority, where I’m like, I’m just here to tell you what to do. But more of like, these are our oceans, these are our corals, and we thrive with our tourism. We need to find a way to protect them and to save them from what’s going to happen. We’re not going to die. But there’s going to be a lot of, for example, environmental refugees. And what are we going to do about that? So my main concern is what’s going to happen with all these people that are going to lose their homes, because that’s the way the world is going, the way the world is going to change.

But at the end of the day, the Earth is going to be fine. What we’re saving is ourselves.

Kerri: We’re going to take a quick break, and when we come back, we’ll look at some of the ways young scientists hope to preserve the resources that are most critical to our survival.

Katherine Bourzac: Hi, Stereo Chemistry listeners, this is Katie Bourzac. I’m a senior correspondent for Chemical & Engineering News based in San Francisco. If you’re interested in climate change, I hope you’ll check out a special project we’ve put together about adaptation to climate change. We’ve got a whole special issue of stories about how chemists are helping the world adapt. You can check out interactive graphics about new materials to protect cities from natural disasters, and how biologists are using gene editing to engineer crops that are resilient to climate change. We’ve also got stories about the ecologists who are saving the coral reefs, technologies to provide safe drinking water, and how industry is learning from past storms like Hurricane Harvey. You can read all this and more in the Feb. 10 print magazine, or online at That’s Thanks for reading, and now back to your regular Stereo Chemistry program.

Gina: So Kerri.

Kerri: Gina.

Gina: Before the break, Diana was talking about how important it is to save oceans and corals from the effects of climate change. But can we even do that? Is it possible?

Kerri: That’s a big question. But, like the students you mentioned who are planning out how to save human-built structures, there are also scientists working on ways we might be able to shield some of the environment from the impacts of climate change. Dave Koweek is one of the researchers who’s looking at ways to preserve the ocean ecosystems we rely on. He’s a postdoc at the Carnegie Institution for Science.

Dave Koweek is exploring ways to help preserve ocean ecosystems.
Credit: Courtesy of Dave Koweek
Dave Koweek is exploring ways to help preserve ocean ecosystems.

David Koweek: I just like fell head over heels in love with the sense of adventure that oceanography entails, and really the feeling of being able to contribute to understanding our planet at a time of great change.

Kerri: And as a former competitive swimmer, Dave says he feels a deep connection to being in and around the water. That’s what led him to study the oceans. And in studying the oceans, he says, the influence of climate change is unavoidable.

David Koweek: I think climate change is not the only environmental problem that we face, but it’s like the elephant in the room; it has its sort of imprint on every environmental problem. And if you want to study our oceans and you want to study how our oceans are changing, you know, really the dominant driver of change in our oceans, I would say, is a changing climate.

Kerri: But Dave wanted to go beyond simply understanding these ecosystems and find ways to preserve them.

David Koweek: Several years into my PhD, I became a little bit impatient with what I felt like was the pace at which scientists were addressing problems in the ocean. I felt like there was a lot of effort and energy dedicated to diagnosing problems, to describing problems in greater and greater detail, to thinking about how one problem combines with another problem to create a super problem. But I felt like we had this incredible sort of base of human capital that wasn’t being applied to think about ocean solutions.

Kerri: So Dave wanted to get involved. In particular, Dave focuses on the problems of deoxygenation and acidification. Remember, the ocean’s low-oxygen areas are expected to expand as the oceans warm as a result of climate change, making them inhospitable to marine life. Ocean acidification happens when the carbon dioxide released by burning fossil fuels dissolves in the ocean, where it forms carbonic acid. The acidity can make it hard for certain creatures to make and maintain their shells.

Gina: Sounds like a chemistry problem.

Kerri: Right, and, on its surface it’s a pretty straightforward one.

David Koweek: In some sense, the solutions are as simple as if there’s not enough oxygen, add oxygen, if the water is too acidic, make the water less acidic. But then you have the question of, well, how do you do that? We can’t do this over large sections of the ocean, but we might be able to do this in small bays and inlets that are kind of disproportionately important for people and local communities.

Kerri: Dave’s working on ways to evaluate some of these potential technologies. But although forcibly adding oxygen or neutralizing acidity in a limited area might buy communities some time to adapt, he stressed that they’re not a perfect solution. They’re not the solution at all, really.

David Koweek: I don’t want to give the illusion that any of these sort of interventions are sufficient to replace the changes that are needed to stop the problems in the first place. Ultimately, the solution to all of these problems are to eliminate them at their source. But science and engineering can provide some novel solutions that help give us time to make these changes a little bit more palatable for the people and the ecosystems that are being most impacted right now.


Kerri: And Dave says he feels a sense of urgency in his work.

David Koweek: This process is iterative, it’s going to take time, it’s going to take a lot of people at the table, and it’s going to take a lot of repetition. And so my concern is that we need to start this now. I think it’s natural to be worried. But I also think there needs to be room for optimism that we as humans have the ingenuity, the drive, the ambition to contribute to solving these problems. You know, we’re clearly not passive agents on this planet. We have created the problem of climate change, and we need to create the solutions, and I think that’s what really gets me out of bed every morning.

Kerri: Dave says these questions are particularly meaningful to him as he considers the next steps in his career and the potential to lead his own research group. He said his goal is to be able to look back at his career, whatever path that career takes, and see that his work has shifted the needle toward meaningful ocean impacts. He’s already seeing that shift start to happen.

David Koweek: I think you start to, you see small signs of hope. You see more and more interest, I think, in early-career scientists and thinking about solutions. And I think you see more and more of an acceptance of this idea that it’s okay for scientists to engage in sort of the public debate, the public sphere. But with all that said, I don’t think that things are moving fast enough.

Gina: It’s interesting to hear how these scientists shift between optimism and, what, apprehension? I mean, Dave and Diana and Rich and Lyssa—these folks know better than I do if we have a shot at fixing this. And, although they’re worried, they don’t seem to think we’re doomed.

Kerri: Yet.

Gina: Right. We’re not doomed yet.

Kerri: And the scientists I spoke with recognize that our future is far from settled.

César Alejandro Urbina-Blanco: We have to do something; otherwise, the world is gonna end.

Gina: Well, I admire his ability to tell it like it is.

Kerri: Same. That was César Alejandro Urbina-Blanco. He’s a postdoc at the University of Ghent in Belgium, and he actually picked his postdoc subject because of its connection to climate change and its potential to help people. You see, he may recognize the possibility that the world could end, but he’s not willing to stand by and wait for it to happen.

César is developing better catalysts to take CO2 from the atmosphere and convert it into useful products, like formic acid. Making that process more efficient—and more commercially attractive—could help reduce the rate of climate change in the future and potentially stave off some of the expected impacts.

Gina: Jeez, maybe I should go into CO2 catalysis!

Kerri: It’s a compelling reason for a career choice, for sure. But César says this was a fairly recent revelation for him, the idea of linking chemistry with climate change. He remembers being like 8 years old and hearing the term “carbon footprint” for the first time on TV, but it wasn’t until he was looking for a postdoc that it occurred to him that he could make an impact with his science.

César Alejandro Urbina-Blanco develops catalysts for taking carbon dioxide out of the atmosphere and turning it into useful chemicals.
Credit: Courtesy of César Alejandro Urbina-Blanco
César Alejandro Urbina-Blanco develops catalysts for taking carbon dioxide out of the atmosphere and turning it into useful chemicals.

César Alejandro Urbina-Blanco: I was always interested in chemistry, but I never really thought about what’s the end product that I could be doing with my chemistry. I thought, okay, I am a chemist, I can do chemistry and at the same time, I can work on a problem that is actually affecting the whole world. And I know that the contributions that we do in the lab are fairly small, and it’s just part of a possible solution. But to think that I can actually have an effect on this, it’s an amazing feeling.

Kerri: And, like we’ve heard from others, despite the obvious challenges César feels a sense of optimism about the future and about the potential for chemistry to mitigate the impacts of climate change.

César Alejandro Urbina-Blanco: I am very frustrated, but somehow optimistic. I’m optimistic because I think that we’ve solved many issues before when it comes to the environment. And if you look at successes from the chemical industry, for example, something that is forgotten now is acid rain. It used to be a huge problem! For many years, it was thought that, oh, this is such a huge crisis, it cannot be solved. And then, boom, science solved it. So I think that we will be able to solve this problem, and I’m confident in science. But at the same time, it is frustrating because you see how many people deny climate change and they refuse to look at the facts and to understand that we have to do something for the environment.

Gina: Wait, we fixed acid rain? When did that happen?

Kerri: Well, in 1990, Congress amended the Clean Air Act to require energy producers to drastically cut back their emissions of sulfur dioxide and nitrogen oxides, which lead to acid rain. Before this, acid rain was getting a lot of attention because it was destroying structures made from marble and limestone, harming aquatic life, and killing microbes in the soil, among other things. Today, the problem isn’t gone entirely, but it’s much, much better than it used to be. And that illustrates another point that César made, which is that many of these environmental solutions we’re talking about—including the one he’s working on—will require support from both the private sector and the government to be successful.

César Alejandro Urbina-Blanco: This is going to take, still, a lot of time. It’s very important that our politicians listen to our scientists, and that they support what we’re doing, that they support our research, and that they support the companies that are trying to cut down their emissions. And at the end of the day, well, companies have to make a profit. So you have to create a path for this to happen.

Gina: That sounds daunting.

Kerri: Oh, you mean reworking an entire energy system that’s been built up over decades? Daunting does not begin to describe it.

You remember Lyssa, the policy pro from earlier in the episode? We heard from her about the connection between air pollution, policy, and climate change. And she also knows from experience that producing results and having those results actually influence policymakers’ decisions are two very different things.

Elisabeth Freese: Rarely will a politician read more than a couple of lines. And at that, it’s usually their science policy intern or advisor who’s reading that couple of lines from an abstract and telling them that, which is not useful. I definitely think that there’s room for improvement on how to better communicate really interesting results in a way that a politician will actually listen to and be able to understand.

Kerri (in interview): Do you get the sense that these policymakers are interested in listening to this data?


Elisabeth Freese: From the conversations I’ve had, I have yet to hear from anyone who isn’t really at least trying to learn. I think, especially with climate being such an important topic in elections these days, etc., it’s really hard for someone to not be willing to learn. I feel disappointed that we have not made more progress. At the same time, I think that watching the current debates going on and seeing, slowly, increases in climate change coming up as a topic has made me realize that they’re not going to get away with not addressing this anymore. That these youth movements have made it very clear that future voters of both parties care a lot about this topic. And that politicians who do not care about it likely will not be as successful.

Kerri (in studio): It’s something that Diana, the microbe scientist, sees as an opportunity for all scientists.

Diana Dumit: There’s been this argument where like, scientists aren’t politicians, scientists should just mind their own business and don’t say anything. But like, how can we do that when our work reflects things that will affect society? We cannot just mind our own business. We have to inform and advise those that make the decisions and hope that they make the right decisions so that we all are able to have the tools to survive whatever comes next.

Kerri: This episode of Stereo Chemistry was written and produced by me, Kerri Jansen. It was edited by Matt Davenport, Lauren Wolf, and Amanda Yarnell. Sabrina Ashwell is our copy editor. The music you’re listening to now is “Cerulea” by Kevin Graham. And the music you heard during our promo was “Plain Loafer” by Kevin MacLeod. Stereo Chemistry is the official podcast of Chemical & Engineering News, which is published by the American Chemical Society.

Gina: Thanks for listening.



Cerulea” by Kevin Graham

Plain Loafer” by Kevin MacLeod.



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