Dr Kate Marvel is an associate research scientist at Columbia University and the Nasa Goddard Institute for Space Studies (GISS) in New York. She received a PhD in theoretical physics from the University of Cambridge in 2008 and has worked at the Carnegie Institution, Lawrence Livermore National Laboratory and Stanford University. Her research focuses on climate modelling and clouds. She writes the Hot Planet column for Scientific American and in 2017 gave a TED Talk on clouds and climate change.
- Marvel on communicating climate change to children: “I feel like, because kids don’t have these long-standing preconditions and thoughts that adults have, they get it and they get it really really quickly.”
- On scientists communicating climate change: “I think scientists can’t do it ourselves. We have to talk to those different communities, we have to learn things and we have to listen.”
- On the “wonder” of climate science: “I feel like a lot of times the excitement and wonder and curiosity get a little bit lost.”
- On why she uses Twitter: “It kind of helps me in my research, because having to think about how do I boil down this thing that I want to say into 280 characters.”
- On being a female climate scientist in 2018: “You get a lot of push back [online]. You get a lot of people calling you stupid.”
- On the next generation of scientists: “I just feel like, ‘oh, man, we are in good hands’.”
- On climate science’s biggest “unknowns”: “Even if you removed that human uncertainty aspect to it, we still don’t know exactly how the physical climate system reacts when, for example, you double CO2 in the atmosphere.”
- On the one climate-science mystery she would like to see solved: “I would want to know what clouds are going to do in the future.”
- On clouds: “Unfortunately, it looks like they’re not going to save us [from climate change].”
- On knowing the value for climate sensitivity: “The only thing policy relevant about climate sensitivity is that it’s not zero.”
- On the IPCC: “It [is] incredibly helpful because no other field writes down everything they know in a giant report every couple of years.”
- On whether 1.5C of global warming can be prevented: “I mean never say never, but my sense is absolutely not.”
- On geoengineering: “I know too much about uncertainties in climate change to not be very scared of side effects.”
- On being a Nasa scientist: “I am very proud of Nasa. I think it’s really the best of this country – exploration and curiosity and science and diversity and a lot of different people working together.”
- On being a Nasa scientist under the Trump administration: “I do think that we have all been very encouraged to keep doing science because physics doesn’t care who’s in the Oval Office.”
- On communicating climate change to Trump’s America: “The vast majority of the country, before Trump, after Trump, and after Trump is gone, I think the vast majority of the country is still in that middle and is still amenable to messages about this is why you should care and this is why it’s OK for you to care.”
- On how to improve the peer-review system: “I would like to see more emphasis on publishing negative results.”
- On what scientific issue is of interest to her at present: “I’ve been thinking a lot about dirt lately and how dirt dries out in the sun…It is the subject of vicious, vicious infighting amongst climate scientists.”
- On what she would do if elected US president: “I’d do a lot of listening. Because, if anybody says that they’ve got all the solutions, you should run from them, because no one person has any of the solutions.”
- On how best to talk to people about climate change: “There are communities I can talk to. There are people I can talk to. But I would never say I have it worked out and everybody should do what I do, because it’s actually the opposite is true.”
Carbon Brief: In simple terms, can you explain what your role as a Nasa scientist involves day to day?
Kate Marvel: Sure. I’m an associate research scientist and I sit at Nasa Goddard Institute for Space Studies, but I also have an affiliation with Columbia [University]. Day to day, I work with a lot of data. I work with the output of multiple climate models. I work with multiple observational data sets. I love my job because, day to day, it’s basically just finding out cool things about the Earth and I think that’s the best job description anybody could have.
CB: What do you think was your earliest ever memory of being aware about climate change? Was it, say, a TV show? A book? A lecture? Can you actually remember that moment as a child or teenager when the penny dropped around the subject?
KM: No, that’s such a good question. I did my PhD in theoretical physics, so I don’t have formal training in climate science. I remember sort of vaguely becoming aware of climate change through undergrad and grad school. Then, when I was a postdoctoral fellow at Stanford, working on science policy, I was looking for something that I could do that would take my background in physics and combine it with something useful that would help the world and be something that people cared about. I remember I went to go to talk to Steve Schneider, who was a very famous climate scientist at Stanford at the time, and he just looked at me and was like, “what, are you stupid?” I think that was when it really clicked that this was something that I could do.
CB: How do you communicate something like climate change, which is very complicated and multi-faceted, nuanced, etc, to children and to a younger audience who don’t understand the details of the science? You could say that applies to a lot of adults as well [laughs], but, stripping it right back down, how do you try and explain it?
KM: Something that I have done, which has been incredibly effective, but also very chaotic, is build a climate model with 11-year-olds. So, the kids are photons and they’re running from the sun to the Earth and they tag the Earth and then run back to the sun. Then you get a couple of kids and you put green T-shirts on them and they’re greenhouse gases. If you get tagged by a greenhouse gas, you don’t get to run back to the sun. You stay back there. You can make this model of varying complexity. You can have kids being aerosols and blocking the sun from coming in in the first place. It makes a lot of sense and the kids are like, “oh, I see why the Earth is heating up…I see what a greenhouse gas is.” I feel like, because kids don’t have these long-standing preconditions and thoughts that adults have, they get it and they get it really really quickly.
CB: How do you think the topic of climate science can be better reported or discussed in the media? It’s become quite a politicised and partisan topic for some different publications and different geographies around the world. For example, you had your own experience in 2015 when the Daily Express had a very eye-catching headline around, “Burning fossil fuels cools planet, says Nasa“. How do you think this relationship between what the science is publishing and saying can go through the mangle or the mill, if you like, of the media?
KM: The short answer is I don’t know. I think there are a lot of ways that we can approach this. There are people who work in public relations and think about how do we communicate complex things. There are artists, there are writers, there are journalists. I think scientists can’t do it ourselves. We have to talk to those different communities, we have to learn things and we have to listen. Something that I do feel like gets lost a lot of the time is the sense of wonder. Because climate science is still science. We’re still finding out really amazing new things. A lot of times the implications of what we find out are kind of disturbing.
But it’s so amazing that we can learn things about the planet. The planet that we have now, the planet that we had in the past and where we’re going in the future. I feel like a lot of times the excitement and wonder and curiosity get a little bit lost. What is really necessary? Saying climate change is real and it’s bad and it’s dangerous? But it’s also amazing to study.
CB: You’re active on social media, like Twitter, for example. As a scientist and a science communicator, why do you use it and what benefits and possible disadvantages do you see from it?
KM: I should probably think deeper about why I use it. Sometimes I haven’t talked to anybody at work all day and I just want to feel like “oh, I’ll talk to all my friends on the internet”. It is kind of a good way to test out ways to say things. Does this resonate? Do people get this? Is this an important or interesting thing to be talking about? I think to a certain extent, it kind of helps me in my research, because having to think about how do I boil down this thing that I want to say into 280 characters and make it interesting or funny or pithy. Like, how do I do that? That’s a really good skill and that makes you think really hard about what you’re trying to say. There are definitely drawbacks. I have blocked or muted a lot of people. People say phenomenally unkind things to you on social media. Sometimes you hear, “oh, you should just get a thicker skin” and I like my skin the way it is. I hurt when people say hurtful things and I think that’s OK and appropriate and they should not say those hurtful things.
CB: On that topic, can you explain what it’s like being a female scientist in 2018 when it comes to communicating and explaining climate change, particularly when online?
KM: You get a lot of push back. You get a lot of people calling you stupid. You get a lot of people calling you uninformed in ways that I think that maybe they wouldn’t say to somebody who looks more like the stereotypical view of the scientist. The flip side of that is there are a lot of phenomenal women out there. Really amazing scientists, really amazing communicators, so you’re not alone and you do feel like you have this unbelievable community of people that you trust and respect and really look up to. And that’s kind of been a positive.
CB: Climate science is obviously quite partisan to some audiences and it’s a potentially hostile career to work in. What advice would you give to the next generation of scientists coming through, the kind of really early career scientist? Or people who have not even made the decision about what area of science they might want to explore?
KM: I’m very uncomfortable offering advice to younger people because a lot of times students will ask me, “what do I do?” I look at those students like, “You are phenomenal. You are so much more together and smarter and just more interesting than I was when I was your age and maybe than I am now.” So I feel like I look at the younger generation of scientists and I just feel like, “oh, man, we are in good hands”. But I think you can’t get bogged down in the politics. You can’t let that get to you. And whatever you need to do whether that’s engaging and fighting back, whether that’s withdrawing, I support the decisions that anybody makes to protect themselves. I think there is no one size fit all answer for everybody.
CB: Moving a bit more onto the science, what do you think are the biggest unknowns about future climate change? Where are the biggest surprises likely to come? I guess it’s a question of known knowns and unknown knowns, if you like.
KM: I can speak to my own research, stuff that I personally am studying right now, and I think there are more amazing unknown knowns and known knowns and other areas that I don’t personally work on. But it kind of blows my mind that we don’t know exactly how hot it’s going to get. And a lot of that is because we don’t know what humans are going to do, what are emissions structure going to look like. But even if you removed that human uncertainty aspect to it, we still don’t know exactly how the physical climate system reacts when, for example, you double CO2 in the atmosphere. That’s because climate change isn’t just temperature. It changes a lot of things. It melts the ice, it changes the water vapour in the atmosphere and it changes the distribution and the amount and the composition of clouds. And those things, which we call feedbacks, really affect how warm it gets. So we can have what scientists call “positive feedbacks”. I hate that terminology because that sounds like a good thing, but that actually means the warming is destabilising, it’s even warmer.
An example of a positive feedback is the sea ice melts and you used to have this nice, shiny, reflective surface and now you have darker water underneath, or, if it’s land ice, darker land and that’s much more absorbent and that process speeds up the warming. If, for example, you got more low clouds with warming, that would be an example of what we call a negative feedback, because those low clouds would block the sunlight coming in. It doesn’t look like that’s going to happen, but those are really amazing for me because they’re examples of how complex the system is. How it’s not just energy and the Earth warms up. There are all these different feedback processes. And that’s something that I’m really interested in.
CB: It’s looking at that question at a slightly different angle, but if there was one thing you’d love to know the answer to in all of your research and wider climate science, what would be that one thing that’s currently unknown that would be of great value to know, or just a personal interest?
KM: I would want to know what clouds are going to do in the future. So it’s 2300, humans are doing whatever we do, but we’ve increased CO2 levels in the atmosphere. What do the clouds look like? I think that would be really interesting to know. [See Marvel’s guest post for Carbon Brief on clouds published in January 2018.]
CB: Do you have a hunch about what they could look like, if emissions continue on the trajectory that they’re currently on?
KM: Unfortunately, it looks like they’re not going to save us. I think for a long time that was kind of the last, best hope that maybe we’ll trade a couple gloomy days, but warming will be slowed down. It wasn’t insane to believe that maybe clouds would reorganise themselves in such a way that they would slow down warming. We are kind of getting more and more convinced that that is not what is going to happen. That’s very exciting because it means we’re learning more about the system, we’re learning about what clouds are actually doing. But, on the other hand, it’s kind of depressing because that means that nature is not going to save us.
CB: Part of your research is around tightening of the ranges of uncertainty around climate sensitivity and that’s often hailed as one of the key priorities of climate science. Where do you stand on this particular issue about narrowing the range of uncertainty?
KM: I’m on record as saying the only thing policy relevant about climate sensitivity is that it’s not zero. We know that CO2 is a greenhouse gas. You put it in the atmosphere, it warms up. I think to a certain extent, we know enough to know that we should probably put less CO2 in the atmosphere. When it comes to the actual real-world implication of narrowing that range on climate sensitivity, that’s important. That’s important for things like, OK, well how long do we have before we cross some warming threshold? But a lot of those thresholds are kind of arbitrary. I understand why people come up with them. We love targets, targets are a good thing. But on a very, very basic level, it kind of doesn’t matter. We know what we need to know about CO2 to know that it is probably not a good idea to keep putting more and more and more of it in the atmosphere.
CB: Talking about the IPCC [Intergovernmental Panel on Climate Change], which has just brought out an interesting new special report on 1.5C, what are your thoughts more generally on the IPCC process? So we have these cycle of assessment reports that come every five, six, seven years and special reports in between. Is this, going forward, the best model for informing policymakers? Or is there possibly a way of improving that system? Or an alternative? And what would you like to see the IPCC do more or less of in the future?
KM: That’s a good question. I’m not sure I’m the best person to answer that. I think I would want to hear from policymakers. I would want to hear from them. What do you need? Why do you need it? What are your motivations for this? What do you not know that we could tell you? I know from my perspective as kind of a baby scientist trying to transition into climate science, it was incredibly helpful because no other field writes down everything they know in a giant report every couple of years. For sort of a new person coming into the field, that’s really useful to be like, OK, here’s what we know and here’s what people are thinking about. So, from my perspective, that was really helpful and I think there’s probably other people who find that helpful. From a policy standpoint, from an electoral or political standpoint, economic standpoint, I don’t know. I would defer to people with more expertise in those fields.
CB: Over the years, there’s been IPCC special reports on a range of different interesting topics. Are there any key candidate topics that you think would be ripe for a special report in the future that they haven’t done yet?
KM: Good question. I don’t know. I think because I am such a scientist and really sort of embroiled in the scientific literature and the scientific debate, there are questions that I’m really interested in that have ramifications because they are questions about climate science. But I’m not sure I want to force all the other scientists to get together and write a big report because of something I personally am interested in. I think reading the scientific literature, reading review papers, those are kind of more useful for me personally as a scientist.
CB: On the topic of the recent IPCC report on 1.5C, which is in response to the aspirational Paris Agreement goal, do you personally feel that 1.5C is still possible? Globally, could we limit temperatures to that? If so, how? If not, what are the issues with that?
KM: I mean never say never, but my sense is absolutely not. I think it’s very, very unlikely that we are going to limit warming to 1.5C. But I feel like 1.5C is an arbitrary target, as is 2C, as is 3C, as is 4C. Obviously, the damages increase with levels of warming, but I did not make this up and I wish that I did, but as my boss Gavin [Schmidt] says, it doesn’t make sense to argue where you’re going to park if you’re still driving in the wrong direction. So my sense is that 1.5C is fairly unlikely, barring some sort of miracle, but that doesn’t mean we shouldn’t try to limit warming as much as possible.
CB: One thing the 1.5C discussion has seemed to have triggered is a big debate around negative emissions technologies and, sort of by extension, geoengineering. What do you feel on those two slightly different topics? The idea that we can draw or suck CO2 out of the atmosphere and store it somehow and also prevent solar energy coming from the sun somehow by deflecting it. Where do you stand on those two issues?
KM: I’m pro finding out stuff, pro research and very anti treating anything like a silver bullet. I don’t know that much about carbon capture and storage, especially the storage part, and I think there’s other people with way deeper expertise than I have. As far as with solar radiation management, like blocking the sun from coming in, my sense is that it’s absolutely possible to lower the Earth’s temperature by preventing sun from coming in – if temperature is the only metric that you care about. But I know too much about uncertainties in climate change to not be very scared of side effects. I think we are pretty sure that that is not going to do anything to stop ocean acidification, or even make it worse. It has the potential to really affect global rain patterns, in some ways that we understand, in some ways that we totally do not understand. I think there are things that could change that we really don’t even anticipate. So I really support a model research into geoengineering, because it really helps us understand, like, “whoa, these are all the things that could totally go wrong”. I am sometimes worried when people talk about it, like, “oh, it’s going to be the silver bullet”, because it might be a bullet, but it’s not going to be a silver one.
CB: We talked about your views on being a female scientist working climate change, but I’m also interested in your views on being an American scientist working on climate change – particularly with the current administration, the Trump administration and his well-known views on climate science and climate change and the Paris Agreement, etc. Obviously, you work for a very high-profile organisation, Nasa. It feels to me as an observer watching that Nasa feels remarkably free just to continue publicly discussing climate change. There were fears there might be a sort of shutdown of views around this issue. Can you just talk a little bit about what, in reality, it’s like being an American scientist, a Nasa scientist, working under this current administration talking and communicating around climate change. On top of that, what safeguards are there in place to ensure scientific independence, etc, and there being no kind of political interference in the scientific process?
KM: I should start by saying I do not speak for Nasa. I am not a federal civil servant. I am a Columbia University employee who happens to sit at Nasa. And that sounds like a really fine distinction, but it means that nothing I say is at all endorsed or coming from Nasa at all. I am very proud of Nasa. I think it’s really the best of this country – exploration and curiosity and science and diversity and a lot of different people working together. I think that’s beautiful. I see people just walking around in the street from all walks of life with Nasa T-shirts. I can’t think of another brand that people love so much all across the political spectrum, all walks of life. I think that’s fantastic and I love that. I can only speak as a working scientist. I have a lot of confidence in the scientific leadership at Nasa. It turns out there are a lot of smart people who work at Nasa. Who knew? [Laughs.] I feel like I have views as a citizen and I do science as a scientist and those things are not completely separate from each other. Science is done by people and none of us can check our biases at the door. None of us can pretend like science is something that’s completely separate from the people who do it.
But I do think that we have all been very encouraged to keep doing science because physics doesn’t care who’s in the Oval Office. And that’s something that I think we really need to keep in mind.
CB: How do you think the Trump administration has affected the climate change conversation in the US and also globally?
KM: I think if you just look at media coverage, it’s very dominated by the loudest voices. So you could be forgiven for thinking that, in the US, everybody either thinks we’re doomed or thinks climate change is a hoax. That’s not representative of where most people actually are. Most people are somewhere along the spectrum of I’m a little concerned or I’m really alarmed, but fundamentally, I’ve got bigger problems. I think that’s fair, because given all of the things that are going on in the country and in the world, it’s very rare that climate change is anybody’s number-one problem. I think that’s an opportunity to talk to people about how climate change affects people and how it interacts with all these existing social structures and existing problems. Because it’s totally fair – if you talk to somebody and they’re, like, I don’t know how I’m going to put food on the table tonight, climate change is not my top priority. The vast majority of the country, before Trump, after Trump, and after Trump is gone, I think the vast majority of the country is still in that middle and is still amenable to messages about this is why you should care and this is why it’s OK for you to care.
CB: Slightly oddball question, perhaps, but is there anything you think can be done to improve the way the peer-review system works as it currently does? Are you happy with the dynamic and also framework in which it operates? Or are there some problems that could be ironed out with the way science goes through this peer-review system?
KM: I think you hate peer review when you’re going through it. It does not feel good. But I kind of suspect it might be the least bad system that we have. I think a lot of the problems with peer review are much bigger than peer review. So there have been multiple instances of gender bias or bias against people with non-European-sounding names. Those are not problems that are specific to peer review, those are larger problems. I would like to see more emphasis on publishing negative results. I think it is very possible to have a very well-designed study that doesn’t find anything and I think that should be much more celebrated than it is right now; really appreciating the beauty of a well-designed study that finds no evidence for the fun thing that they were looking for. I think that’s incredibly useful and we should really celebrate that culturally more. But as far as peer review goes, I haven’t heard any sort of sweeping suggestions that I think would fix problems with it.
CB: You’ve recently this year begun a regular column in Scientific American. That’s an interesting challenge to take on. Why did that appeal to you to do that?
KM: Lots of people have been asking me that. I wish I had a better answer. It sounded kind of fun. It sounded like something that would actually force me to write every now and then. Just sort of sit down and collect my thoughts. It’s been interesting to see the reaction. Generally, I’ve gotten a fairly positive reaction, so if anybody has any suggestions, good faith suggestions for things they’d like to see written about, I would love to hear those. But it’s been interesting.
CB: Do you have an exhaustive list of topics, or do you feel there’s a kind of finite time or number of those types of columns that you could do? That you will work your way through those topics you feel like you want to tackle?
KM: I think things happen all the time. Current events happen, new science happens. We’re never going to run out of stuff to talk about. I might run out of patience and I might run out of interesting things that I personally can say. But, no, I think science is always finding cool new stuff. And it’s a bit of a challenge to set yourself. You know I’ve been thinking a lot about dirt lately and how dirt dries out in the sun, which is incredibly interesting to me personally and incredibly useful if you want to look at things like drought projections in a future climate. It is the subject of vicious, vicious infighting amongst climate scientists, like, “what is the best way to quantify this”? So it’s really useful to me to sit down and think about how do I make this fight about dirt indicators interesting to people outside this very, very small community? Because it is interesting and it does matter. But trying to think about how do I write about that in an interesting way actually forces me to think about why does this matter. And that’s really useful.
CB: A world powered on 100% renewables. Is that realism, or is it fantasy, in your view? This wider debate about how we are going to change our energy systems. There’s lots of views, but what’s your view on this?
KM: I’m pro math, as [Prof Sir] David McKay used to say. He wrote this book, Sustainable Energy Without the Hot Air, that I think is really really worth checking out. I am not an energy policy analyst. I’m not an economist. I don’t know enough about these socio-political and economic implications of switching our energy mix. So I know that there are very, very strong debates happening about the world of nuclear and the world of natural gas as a bridge fuel, but, fundamentally, I’m a physicist and it’s my job to tell you what the CO2 does once you put it in the atmosphere. But I don’t feel qualified to tell you how to not put it there or how to get it out.
CB: So you’ve been elected as the next president of the USA, which you’re obviously pleased to hear. [Laughs.] What do you do on day one when it comes to implementing the type of climate- and energy-related policies that need to happen? What would be the priorities if you had all those levers of power?
KM: Oh my gosh, I’d get on the phone and I’d call people who know what they’re talking about. I think we do, as a society, have a lot of those people. There are things that experts agree on, even though they’re fighting about the stuff on the margins. There are clear policies that people from all ends of the political spectrum arguing in good faith say, “no, this is what we need to do”. So I’d get on the phone and I’d talk to economists, I’d talk to community activists about “hey, do you know how this is going to affect your community? What do you want?” And I’d do a lot of listening. Because, if anybody says that they’ve got all the solutions, you should run from them, because no one person has any of the solutions. This is not something that’s amenable to a simple stereotypical TED talk – “I’ve solved everything with my new technology” – this is something that really is going to require input from all over the place. And I think there are really smart people and they’re all over the place. They’re in all these different fields, they’re in all these different disciplines. I recognise that the American people have made a giant mistake [laughs] and I try to do my best.
CB: OK, final question. As a science communicator and a climate scientist, you might have noticed online, as you’ve already said, it’s quite a partisan and hostile environment and there are some people out there who don’t believe in the science, or they doubt the science. As a scientist and a science communicator, what’s the best approach for those people? Will you just continue trying to talk to them, explain to them? Or are there sometimes moments where you think, “OK, this isn’t going to help. I can’t reach them, it’s going to be for someone else, maybe, to try and reach them”?
KM: I think this is why there is no one solution. This is why you need everybody talking about this. People that I can’t reach because I don’t have any credibility with them, I’m not in their community, we don’t speak the same language, they don’t perceive us as having the same values, they won’t listen to me, but they’ll listen to Katherine Hayhoe or they’ll listen to David Titley, who’s a rear-admiral in the navy. I think it’s really important that we have a wide range of voices talking about this. If I go into a particular community and I’m not part of that community, there’s going to be a barrier there and it doesn’t matter how flashy my charts are, or how rigorous my statistics are, because a lot of times it’s not about science. A lot of times it’s about: “Do you think that we have the same values? Do you trust me? Do you find me credible?” I think there are communities I can talk to. There are people I can talk to. But I would never say I have it worked out and everybody should do what I do, because it’s actually the opposite is true. It’s really important for very few people to do what I do and people do what they do and what works for them. I think that’s really important.
CB: Great, OK. Thank you.
KM: Thank you.
The interview was conducted by Leo Hickman at Columbia University in New York on 25 September 2018.