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Gravity Assist: Meet NASA’s New Chief Scientist, Kate Calvin

Season 1Jan 28, 2022

Climate change is one of the most important issues facing our planet, and NASA has lots of space missions and programs in the works to monitor and understand its drivers and effects. Kate Calvin, NASA’s new chief scientist, is also the agency’s senior climate advisor. In this episode, Kate previews  upcoming Earth science missions and discusses cut

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Close-up view of sea ice floes from NASA's DC-8 Research aircraft. The dark features on the ice are melt ponds, and the dark areas of between the floes are open water of the Arctic Ocean.

Climate change is one of the most important issues facing our planet, and NASA has lots of space missions and programs in the works to monitor and understand its drivers and effects. Kate Calvin, NASA’s new chief scientist, is also the agency’s senior climate advisor. In this episode, Kate previews upcoming Earth science missions and discusses cutting-edge research endeavors to explore climate change.

Jim Green:The Earth’s climate is changing. And NASA is making key observations to see what it’s all about.

Kate Calvin: Climate change is about more than just changes in temperature. There’s a whole host of other earth system changes that come along with this, like changes in the water cycle, which can lead to more floods and more droughts at the same time.

Jim Green: Hi, I’m Jim Green. And this Gravity Assist, NASA’s interplanetary talk show. We’re going to explore the inside workings of NASA and meet fascinating people who make space missions happen.

Jim Green: Welcome back to Gravity Assist. I’m your host, Jim Green, and I have a new job.

Dr. Kate Calvin at the NASA Headquarters Mary W. Jackson building in Washington.

Jim Green: In January 2022. I retired from NASA, but they hired me back working on some very special projects.

Jim Green: So in our first episode of season six, it gives me great pleasure to talk to the new chief scientist of NASA, Dr. Katherine Calvin. And she is also the agency’s climate advisor. You know, climate change is such an important topic, and we are thrilled to have Kate on board at NASA.

Jim Green: Kate is a distinguished climate scientist who comes to us from the joint Global Change Research Institute at the Pacific Northwest National Laboratory. She has also been a research scientist at the University of Maryland in College Park. Welcome, Kate, to gravity assist.

Kate Calvin: Thanks, Jim. It’s great to be here.

Jim Green:First, tell us a little bit about what are you going to be doing in your new role?

Kate Calvin:Yeah, I’m really excited. I’m now the chief Scientist and senior climate advisor at NASA, and as senior climate advisor my role is really to connect the climate science within NASA. NASA does a lot of climate science throughout all of the mission directorates and trying to bring that together so people know what they’re doing and what everyone’s doing. I’m also going to be working towards communicating that science externally, working with other agencies in the United States, and communicating with the public. In general, as chief scientist, my role is really broader than that, focusing on all of NASA science.

Jim Green: Wonderful, this is really going to be a wonderful era, where NASA takes a larger role in explaining the changes that are occurring on our beautiful blue planet. Well, can you talk about how you got into climate science? Is this something that you’ve always wanted to do?

Kate Calvin: So I My background is in math and computer science and engineering. And when I was going into grad school, I knew I liked math and computer science, but I wasn’t exactly sure what I wanted to do with it. I’ve always loved being outside, though. So as a kid, we grew up around boats, and I did a lot of camping. Over time, I got more into hiking and biking. And climate change was one of these ways of combining my technical skills with something that really mattered to me. So when you spend a lot of time outside, you develop an appreciation for nature. And you notice weather. And climate change is a really nice way for me to tie together something that I loved was something I knew how to do.

Jim Green: Well, you know, a lot of people get confused between weather and extremes of weather, and what we talk about as climate of the Earth. Can you give everyone a little insight as to the difference between those two?

Kate Calvin: Sure, from a scientist, what we like to think of is: Climate is long term weather. So if you’re, you know, then if you look at how many hot days you have any year, there’s going to be some variation from one year to the next over time, if you have more hot days, that’s a climate signal. The analogy I heard most recently, actually, on one of your podcasts was about wardrobe, though. And so you can think about your outfit for the day being weather and climate being your wardrobe. And so I think if you think about climate change in that context, over the pandemic, I think we all bought a lot more sweatpants since we were working from home. And so that’s sort of a shift in our wardrobe. So you could still wear jeans, because that was the weather that you had access to. But with more sweat pants in there, you’re seeing more and more sweatpant days. And so in the in again, in the analogy of climate change, you know, your wardrobe is climate. And so as we get warmer and warmer, you have more and more hot days.

Jim Green: Why do you think it’s important that NASA is focusing so much energy on climate change right now?

Kate Calvin: So NASA has been doing climate and Earth Science for decades. So they have a decade’s long set of data on Earth and atmospheric conditions that give us a sense of both where the Earth is today, but also where we’ve come from, since we’ve been doing this for decades. And one of the things you can see from NASA data and others is that climate’s changing. So we just had a release of the update of the temperature record jointly with NOAA, and 2021 was tied for the sixth warmest year on record, and the last eight years are the warmest years on record. And so we’re experiencing these more extreme events, and they’re going to continue with warming. And NASA has this unique vantage point of space to see the Earth and to be able to provide information that’s relevant to decision makers and stakeholders.

Jim Green:Well, tell us about the upcoming NASA climate science activities. I know we’ve got a bunch of launches. What are you excited about in this area this year?

Kate Calvin:Yeah, we have a lot of launches planned for 2022, I’ll just highlight a few. So one of them is the SWOT mission that’s coming out towards the end of 2022. This is a satellite that’s jointly developed with CNES, the French space agency, with contributions from the UK and Canadian space agencies. And it’s focused on measuring oceans and surface water. So it’s going to look at lakes and rivers and how rivers flow. And also how oceans are changing. And oceans are really important in climate because they absorb a lot of the heat. So as the Earth warms, the oceans are taking up quite a bit of that. Similarly, they absorb a lot of carbon and SWOT will allow us to better understand the oceans role in a changing climate.

Kate Calvin:One of the other ones I’m really excited for is an instrument that’s going to be launched onto the International Space Station. This is called EMIT and it measures mineral dust from the space station and mineral dust is important both for local climate, but also air quality. So it affects the quality of the air, which has implications for human health and other things.

Jim Green: Well, you know, when I was at Goddard Space Flight Center, and I was working with their climate people, on occasion, what I was seeing coming out of their models, over time, as they added CO2 was changing weather patterns. You know, where areas that were desert was getting more rain, where there were forests, they would become, you know, more arid over time. And so breaking records, temperature records, and looking at those extremes over long periods of time, seems to already give us the idea that the climate is changing. Is that still going on today?

Kate Calvin: Yes, so the climate is changing. We are seeing again, these increases in heat extreme increases in fire weather, which is particularly important in parts of the US. And NASA has a modeling program that does look at, you know, how is this changed in the past and how it might change in the future so that we can better understand those effects going forward.

Kate Calvin:But I think on your point, it’s, you know, climate change is about more than just changes in temperature. There’s a whole host of other Earth system changes that come along with this, like changes in the water cycle, which you know, can lead to more floods and more droughts at the same time. And it can lead to changes in our forests and changes in in the whole Earth system. And so that’s something that we’re looking into both from an observation perspective to understand where we are now and how we got here, but also from a modeling perspective to understand where we might go.

Jim Green:Is there a particular question about our changing climate that you’re really interested in answering scientifically?

Kate Calvin:Yeah. So there’s a lot of things as a scientist that I’m really interested in the one that sort of stands out for me, has to do with exactly understanding how much the Earth will warm for a given level of emissions. This is something in the science community called climate sensitivity. And we’ve recently narrowed that range, so we have a better understanding than we did before. Unfortunately, that narrowing is that we’ve eliminated the possibility of low warming responses. So now we think that the warming for a given emissions level is at least a certain level higher than we thought before.

Kate Calvin: But really understanding how climate responds to emissions is really important for decision makers as they’re planning mitigation actions, but also adaptation. So how much warming might we expect? And how do we respond to that? And so I think the more precise we can give that information, the better it is for people making decisions.

Jim Green: Isn’t it also true that there’s some climate inertia going on? And maybe that’s not the right way to describe it, where, where, even though we may be making progress, and overall reducing our emissions of CO2 and other greenhouse gases, it’s gonna take a while for the climate to really respond to that?

Kate Calvin: So warming will stop when we get emissions to what’s called net zero, so that effectively any extra carbon dioxide we’re putting into the atmosphere, we’re also taking out. And at that point, you know, there’s some other nuances in that. But that’s really that’s how you stop warming.

Kate Calvin: I think you could think of this like a bathtub. And so as long as the faucets on and waters going in, the water level is going to keep going up. If you can turn off that faucet, or balance the water coming in with water you’re scooping out, then the water level will stop. And so that’s that’s where we understand about climate change. So stopping carbon dioxide emissions is a precursor to stopping warming.

Jim Green:ell, you’ve done a lot of computer modeling studies, I see, about different scenarios in the future, and ways to mitigate these effects of climate change. Tell us about a couple of those that you’re especially proud of.

Kate Calvin:Yeah, so one of the highlights for me was this effort I worked on a little more than 10 years ago. For people in the science world, it’s called the representative concentration pathways or RCPs. But what these were was a set of scenarios that were really designed to tie together the research community. So there are people out there that look at how do changes in emissions affect climate. There are other people that looked at how you might change emissions, and how does changes in energy affect emissions? There are people that study what the impacts are. So if we have warmer weather, what does that mean for wildfire and heat extremes? What does that mean for food production? And those are all separate groups of researchers. And this project was a way of connecting all of that.

Jim Green: Have you ever gone out into the field as part of your research?

Kate Calvin: Yeah, I got this opportunity a few years ago. It’s not a tradition in the world I come from because we build computer models. So we write code and we stare at computers But one of my co-workers was a forest and soil scientist. And he took me with him to do some field research his area at the time, he was looking at how forests recover after fire. So we spent a week hiking around in measuring trees in Canada. And it was a really, really interesting experience for me both to see where the data that I was using in my model comes from. So I was doing a lot of modeling of forests. And here was an actual forest. And so I could see where are these numbers I’m using coming from.

Kate Calvin: It was also really useful to see heterogeneity. So not every tree is the same, not every forest is the same. And that’s hard to see when you’re just looking at a computer. I think it also really gave me an appreciation of satellites. So in one week, the two of us carried covered a very, very small fraction of one part of the world and measured those trees. And if you really want to understand the world’s trees, you need to be able to do more and see more. And that’s something that satellites give us.

Jim Green: But indeed, that that fieldwork is really critically important because it gives you what we call ground truth, of course. And then you can compare those observations from the ground with those from space and make other inferences.

Kate Calvin:Absolutely, I think the fieldwork in the on the ground research is really important those that understanding the system you’re in and that satellites do give us global coverage. After you’ve done that.

Jim Green:Can you tell us a story about a moment in your work when you had to surmount an obstacle? And what was the challenge and how you overcame it?

Kate Calvin:So a lot of the challenges I’ve faced in my work have to do with communication. So I a lot of my work is very interdisciplinary. I work with physicists, ecologists, economists, chemists. And when you’re working across disciplines, one of the challenges comes, are we speaking the same language? And are we doing the things that we intend to do? And so one of the projects I worked on a few years ago, was about linking these two different types of models of the climate system. So one of the parts of the project was about looking at how climate effects land, another part of it was looking at humans might respond to those changes in land.

Kate Calvin:And we were trying to link information back and forth between them. After a couple of rounds of exchanging information, we started to get some results that were surprising. And when we dug into it a little bit, what we found was that what one model was producing wasn’t actually what the other model needed, but we didn’t notice it, because we didn’t communicate clearly enough when we are setting up this design.

Kate Calvin: And I’ve had a lot of variations of this challenge in my career about that. And I think it’s pretty natural, different words mean different things to different communities. And the way that we address these sorts of things, is to just keep asking questions to be precise in our language, but also verbose. So not just giving an acronym or a word, but also explaining what that means to us. And so you have to be open to the idea that a word might mean something different to someone else, and really work with them to communicate that clearly.

Jim Green:Well, you know, I have always said, science isn’t done until you communicate it. And I mean, between scientists but also the public. What do you think are some of the really big challenges to talk about the current observations and what may evolve with our climate to the public?

Kate Calvin: So some of the challenge, I think with the current observations, it’s sometimes it’s a little bit easier in the sense that people see that right. So we know that there were wildfires, we see extreme heat events, I think the numbers can get challenging there. So you hear one degree Celsius. And that’s hard to interpret. It sounds very small. But really all of these impacts come along with it. And I’d say also on that, since I just said Celsius, depending on the audience you’re speaking to, you have to think about units. And so the science community works in metric units. A lot of people in the United States understand Fahrenheit. And so trying to think about that and do that translation, as you’re talking is really important. When you’re thinking about future. One of the challenges there, I think is that, you know, future warming depends on future emissions. So we can’t tell you for sure how warm that will be, in part, because it depends on what happens between now and then. And I think that’s a really hard thing to communicate sometimes is that, you know, what we understand what we don’t why we don’t understand it. And so a lot of this future warming, it’s because it depends on our emissions between now and the future.

Jim Green: Well, you’ve also done some work with the Intergovernmental Panel on Climate Change, or what is commonly called the IPCC. What is that organization? And what does it do?

Kate Calvin: Yeah, so the IPCC is the United Nations body for assessing the state of climate science. The reports are written by scientists, for the IPCC. And they come out every seven or so years, and they assess the state of climate science. So they’re not doing new science. They’re looking at all of the peer reviewed publications that have come out in the last decade, and assessing what do we know about climate change, and what don’t we? And one of the nice things about the way that the IPCC works is it every sentence that they write has a confident statement. So we can tell you how much do scientists agree on this? How much knowledge do we have in this space? And where do we need more?

Kate Calvin: The other thing that’s really interesting for me about the IPCC, and back to our communication, conversation, is at IPCC, the final summary for policymakers, they’re approved word by word by governments and scientists. And so it’s, it’s an opportunity to really think about how do I communicate my science clearly to someone that needs to use it?

Jim Green:So as chief scientist, you also look over all the other science activity that NASA is doing, what else that we have in our portfolio is exciting you?

Kate Calvin: I’m really excited about the James Webb Space Telescope. I’m sure most people are. So I got up early Christmas morning to watch the launch. And I’ve been following as it’s unfolded the mirrors and we’re expecting first images from it this summer. And so I’m really looking forward to that. I’m also intrigued by the DART mission, which is going to try to change the orbit of an asteroid. And then as someone that you know, watched Apollo 13 as a kid, we have some upcoming robotic and human missions to the Moon under Artemis, that’ll be really fun to watch.

Jim Green:Well, I know there’s a lot of budding scientists in our audience. And math and computer science is so important. What would you suggest people do to get excited about going into this field?

Kate Calvin: So one of the best pieces of advice I got in grad school was to just take the best opportunity when it comes. So don’t try to plan too far ahead, look at what excites you that day, and pursue that. And I think for me, that’s what I really been focused on. I started out, I just, I knew I liked math. When I got to undergrad, I decided I liked computer science, too. When I got to grad school that turned into climate science. When I got to my my job, joint Global Change Research Institute, it turned into interdisciplinary science. And now I’m doing science more broadly, not just climate science. And so I think, just follow where it leads and be curious, ask questions. There’s no wrong question.

Jim Green:Well, Kate, I always like to ask my guests to tell me what was that person, place, event, or thing that got them so excited about being the scientist they are today. And I call that event a Gravity Assist. So Kate, what was your gravity assist?

Kate Calvin:Yeah, so there’s a lot of people that have had an influence on my career. So my high school calculus teachers, the reason I majored in math. My grad school PhD advisor is the reason I do climate. But the person I’ve been thinking about the most, in the last few weeks since I started at NASA is a guy by the name of Tony Janetos, who was the director of the joint Global Change Research Institute when I started. He was also a former NASA program manager. And at the point where I started at the institute, you know, I was doing climate research, but I was very much engineering-focused. And I worked with a lot of people that were like me, had degrees in my department. And Tony was an ecologist. And he was very much encouraged me to do interdisciplinary research, and to talk to people that had a different perspective than me. And I don’t think I’d be where I am today if it weren’t for the encouragement that he gave me.

Jim Green: Well, Kate, thanks so much for joining me and talking about this incredibly important topic, and how NASA can play an important role into the future.

Kate Calvin:Thank you so much for having me.

Jim Green: Well join me next time as we continue our journey to look under the hood at NASA and see how we do what we do. I’m Jim Green, and this is your Gravity Assist.


Lead producer: Elizabeth Landau

Audio engineer:Manny Cooper