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Episode 12: Digging Deeper with Kristin Bergmann


Digging Deeper with Kristin Bergmann, Asstant Professor, Massachusetts Institute of Technology, and 2019-2020 AAPG-AAPG Foundation Distinguished Lecturer.

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VERN STEFANIC: Hello and welcome to AAPG's Energy Insights. I'm Vern Stefanic. And this is another podcast from AAPG in our ongoing series Digging Deeper. Specifically, a conversation with one of the speakers for this year's AAPG Foundation's Distinguished Lecture series. Our guest today is Kristin Bergmann, Assistant Professor of MIT's Department of Earth, Atmospheric, and Planetary Sciences in Cambridge, Massachusetts, and holder of the prestigious Packard Fellowship in Science and Engineering. Incidentally, Kristen's DL lecture, which is available for either downloading or streaming on the AAPG website, is titled "Reconstructing Earth's Climate Dynamics at the Dawn of Animals." Talk about timing. And we'll talk more about that in a moment.

But today, we get to also know a little bit more about Kristen, the work that went into her research, and the path and passion that brought her to this moment in her career. Kristen, hi, welcome to Digging Deeper, AAPG's podcast. So good to have you with us, especially talking about what you were talking about on your distinguished lecture, which seems very timely, right? You're talking about something that everybody is interested in, which is a little bit about climate change in our Earth and the way climate is impacting our earth. And maybe how that happened a long, long time ago. What, 500 million years ago?

KRISTIN BERGMANN: Yeah, something like that, between 500 million years ago and a billion years ago. That's the time period I think most about. But yeah, I'm really excited to be here to talk about climate and other things. So thanks for having me on.

VERN STEFANIC: Great, because we're going to talk a lot more about that. But before we even get to that, just I would be curious to find out more about you and how you got to this moment where you're talking about all of this with us. Is this something that you aspired to from when you were a little girl?

KRISTIN BERGMANN: No, I did not know that I would be a geologist when I was growing up. So I would say there are some things that a lot of geologists share. So I did a lot of looking out the car window on family road trips, hiking, spending time outdoors at summer camp in the summers, just appreciating the natural world, seeing, watching patterns in the landscape.

VERN STEFANIC: Do you remember-- was there a moment? Do you remember a moment that really meant something special?

KRISTIN BERGMANN: Certainly, I remember my eighth grade like earth science class and really enjoying learning about the earth in that setting. I reached out to that teacher years later just to remind her that it meant something to me.

VERN STEFANIC: What are some of the places that you remember visiting that kind of stuck out?

KRISTIN BERGMANN: Yeah, certainly the Alps and just the rugged topography created by glaciers. That was stunning. There is this one road cut that we'd always drive-through going to visit my grandparents in Ohio-- the Cumberland Gap. And there's this big U-shaped incline. And after I took my first geology class in college, I actually drove out by myself to visit my grandparents. And I got to stop at the visitor center and walk the gap and just absorb this incline. And that summer, I decided that I would be a geologist.

VERN STEFANIC: Oh, oh, great. So right from then, you knew going to college that was what the career was going to be. That's cool.

KRISTIN BERGMANN: It took one introductory geology class in college to cement it, for sure.

VERN STEFANIC: Oh, man, wonderful. And tell us a little bit about what was your experience as far as college? And I'm sure there were some graduate degrees, as well.

KRISTIN BERGMANN: Sure. So I was at a small school in Minnesota, Carleton College, for my undergraduate. And they've actually produced a lot of great geologists. And I love it. I think that instructors and the professors there say, you know, the Minnesota rocks are simple around Carleton. And we'd go out every week twice a week and just look at these flat lying Cambrian, Ordovician sedimentary rocks. Some of the carbonates I've actually used in my research since graduating. But it was a phenomenal place to learn to look at rocks, because initially you could not have to deal with faults and cover and complications.

VERN STEFANIC: Yeah, yeah. So OK, so you come out of Carleton ready to tackle the world. What did you want to do at that point?

KRISTIN BERGMANN: Yeah, so after I graduated, I was curious to explore different careers and career options in geology. So I spent one year seeing if hydrology was the right fit. And I worked for the Interstate Commission for the Potomac River Basin in Washington DC. And they do a lot of water quality, water management. And that was a lot of fun, but I also missed interacting with people about science on a daily basis. So then I decided to teach middle school earth science and life science.



VERN STEFANIC: Oh, my. Where was that? How was that experience?

KRISTIN BERGMANN: Yeah, so I taught in New Jersey at a school where basically the teachers did it all. I drove the school bus. I taught the sixth and seventh grade science classes. I coached the middle school swim team and the JV girls' soccer team. And it was a lot of fun. It was a really great way to interact with kids of all ages, but I really loved teaching the middle schoolers about the earth. At that age, I think science is approachable for everybody. Nobody's turned off science at that point. And I think that they do have a lot of enthusiasm for looking at the world around them and wanting to understand it.

VERN STEFANIC: Did you find yourself at that point remembering or emulating the teacher that meant so much to you?

KRISTIN BERGMANN: So I don't know that I could remember a lot about the things she did when I was an eighth grader at that point, but I did really appreciate the freedom I had to be creative with how I taught the students earth science. I actually had these-- to teach them about bioturbation, I had plaster of Paris, with pink plaster of Paris and white plaster of Paris. And they'd drag fishing lures through it to make worm burrows. And I actually got to bring them on to the rock outcrops in and around where the school was in New Jersey, so that they got the experience of what field work was like and saw rocks with raindrops imprints in them and ripples on them. So that really felt like a special way to reach students, was to bring them to the field.

VERN STEFANIC: And obviously, teaching is still very important to you. And we'll talk a little bit about that a little bit later. But you also like to be out in the field, as well. So since you're no longer teaching in New Jersey at the middle school, something must have happened next that made you think, oh, there's something more.

KRISTIN BERGMANN: Yeah, so actually I had a sense of there was something more even from graduating from Carleton. We did a senior thesis as part of undergraduate. And I really dug in. I just loved the research. I was up in the high alpine meadows in the Sierra Nevada mountains for two summers, looking at the connections between the landscape and the hydrology and the vegetation. And so I thought I would like to go back to graduate school, but I wanted to try other things first. And actually I think it was a really nice window of time to explore before thinking about graduate school.

VERN STEFANIC: Yeah, this whole idea of being out in the field was always-- it sounds like that was always kind of a key part of your life.

KRISTIN BERGMANN: Yes. I don't know what it was, but it's-- even today, balancing career and my family, my husband will always say, for a field work opportunity, go to the field. This is the time that you're happiest. And it's great to have that support.

VERN STEFANIC: Yeah, we're going to talk a little bit more in just a few moments about some of the other places that you've been. But before that, I just want to finish up the loop. So grad school did wind up calling again. Can you take us through that, in terms of not just where you were, but the influences that might have had on you?

KRISTIN BERGMANN: Yeah, so I was at Caltech in Southern California. And I got to work with amazing scientists there. It was one of those where, by the time I finished my PhD, I sat solidly in the middle of even three different faculty there and learned from four or five others so much about how they do science. And at the time I was there, one of my PhD advisors launched the Curiosity Rover to go look at the sedimentology on Mars.

VERN STEFANIC: Of course, yeah.

KRISTIN BERGMANN: And I got to do fieldwork in so many places as part of my PhD. So we did big field campaigns to the Sultanate of Oman every year. I'd go. I'd work in the corps shed over there for another month, explored modern carbonate environments in the Bahamas. So I felt like a grad school is really the time that I got to spend a lot of time exploring the rock record.

VERN STEFANIC: Like you say, you got to go to a lot of different places. You're quite an adventuresome type, it sounds like.

KRISTIN BERGMANN: I guess so, yeah.

VERN STEFANIC: That's true.


VERN STEFANIC: So you come out of that. And you had mentioned earlier that you were kind of working in environmental areas at one point. And now you're seeing the earth. Did these dynamics start kind of working together in your career of things that you wanted to pursue?

KRISTIN BERGMANN: Certainly. I think that we're all living on this planet at a time when the planet is changing a lot. And so I think being out in the elements, you get attuned to that a little bit more quickly. And so, for example, one of the places that I've been doing fieldwork recently up in Svalbard, it's a high arctic setting and so it's seeing a lot of warming. And just being out there day after day, the first field season, we got dropped off by helicopter and we were there for a month. And you're in the wind and the rain and snow. But we also we're seeing geysers of water coming out of the glaciers. And these are glaciers that scientists in the decades before I was there could ski over. And so just traveling to all these places, I feel like I've really gotten a pulse of the ways that the Earth is changing now in real time.

VERN STEFANIC: There's a lot of people who are talking about that, too. But sometimes the public debate on this is maybe more confusing or frustrating than it is helpful. Have you found-- everybody says that maybe we should be talking about the science of things. You seem to be someone who's actually at that crucial point.

KRISTIN BERGMANN: When I watch the news coverage, it feels like it's a lot about what someone believes and it's less about what we could be doing and the magnitude of the problem for the people who are experiencing this. So I feel like Hurricane Harvey or the flooding in the Midwest, people are on the ground experiencing this weather. And if you look at what they say, they'll talk about never seeing anything like this in their lives. And yet, that's not what we're having a conversation about nationally. And we're not having the conversation about what we can do. And I think that's what I would like to see us doing.

VERN STEFANIC: As a geologist-- in fact, as the distinguished lecture this year, you have a topic that kind of is about that, but takes a more geologic time frame look at things. Could you tell us a little bit about how your talk-- how did that even start in your life?

KRISTIN BERGMANN: Yeah, so I think that there's often a lot we can learn from the past. And I guess I've always felt this way, because before I knew I would be a geologist, I thought I'd be a historian. And I say, I just study the history of the Earth now. But I think that the past, it is a replication of what we're experiencing now. And there are subtle differences and different ways that a given climate event manifested in the rock record, but each of them, I think, gives us insights about what we can expect and what we're experiencing now. And so just like you might say, we should pay attention to what caused world wars, so that we can avoid them in the future, I think we can pay attention to climate events in the past.

VERN STEFANIC: Well, could you talk a little bit-- and everybody should just take advantage of the fact that your distinguished lecture is on the AAPG website and you go into a lot of detail. We don't want to just recreate that talk right here. But briefly, can you tell us a little bit about-- and actually, let me interrupt myself and say that I love the fact that you said you wanted to be a historian. Because a historian basically tell stories about what happened and make it something that we can all understand and comprehend. You have done that basically looking at the ancient history of our planet. And maybe it's come up with perspective that others of us haven't even thought about, let alone realized. Could you talk a little bit, without giving your whole talk away, but tell us a little bit about--

KRISTIN BERGMANN: Right, so in working to read the rock record during some of these past climate events, I started to get the sense that-- one, they were climate events. That was not a given when I started my research. And two, that they were evidence that Earth's climate used to work very differently. And so it really took time for me to think about how it might have changed to get us to today.

And that was an interesting process, where I tried to piece together, I think, the components of the system that seemed to be magnified in the past that were more muted today-- temperature change being one of them. And as I looked at the components of the system, I got this insight that perhaps carbonates were key. And specifically CO2 sequestration into carbonates. And so that's when I started pulling the record, pulling at this kind of bigger scale record of the entire globe and how it might have changed through time to understand the controls on climate changing.

VERN STEFANIC: So we're talking about 500 million to a billion years ago, there was climate change that was occurring at that time. And there were some surprises. Could you be a little bit more specific about what some of that-- well, what kind of climate change are we talking about?

KRISTIN BERGMANN: Yeah, so the kinds of climate change that I think make everybody sit up, right? So during that time period, there were these events we call snowball Earth events. So just imagine the entire Earth as a big snowball. And that's how, at least when we first appreciated evidence for ice at the equator, we envisioned this period of time. And in and amongst those snowball glaciations, it looks like there were equally extreme warm events. Nothing like what the earth has seen in the last 500 million years, so they were there were more extreme than anything we've experienced since or anything the Earth has experienced since.

VERN STEFANIC: Help some of us who are not scientists. So how did how were you able to determine that?

KRISTIN BERGMANN: Right, so what I like to say is that Earth's climate system affects a lot of different aspects of how the earth works. So the windiness, the amount of dust in the air, the temperature profile in the ocean, how stormy it is. And so thinking about all of the ways we think the Earth is changing today or through maybe another recent climate event, like the Paleocene-Eocene Thermal Maximum, gave me an idea of what the rock record might look like for a very extreme climate event and something to test. So I actually think that there were thick deposits of dust being deposited and bigger storms than we've experienced recently. And all of that is because the Earth's climate system was warmer.

VERN STEFANIC: This was a period before we had dinosaurs and big complex animals--


VERN STEFANIC: --or anything. Yeah. So what did that mean for life on Earth when all this was happening?

KRISTIN BERGMANN: Yeah, so simple bacteria and archaea can withstand a lot. And so the potential for its climate doing different things I think is greater, because they can withstand it and life can carry on through, like we know it did. This interval of time when we see the most evolutionary change, with innovations in macroscopic body plans and the ability to create skeletons out of calcium carbonate, all of those changes in the fossil record are occurring with this backdrop of extreme climate change. And so it really, I think, makes me think that the climate dynamics, perhaps even both the cold and the hot, were important in driving evolutionary innovation.

VERN STEFANIC: How is this going to impact us going forward and our knowledge of the Earth?

KRISTIN BERGMANN: Yeah, so I think it definitely helps us understand our roots and where we came from to understand the selective forces that were at play and how those may be affecting components of at least the eukaryotic life system as a whole. I think it also helps us think about the future for thinking about extinction pressures and selectivity with what things can't survive high temperature events. So we see extinction selectivity at a variety of warming events in the rock record. And it's fascinating what goes extinct. And unfortunately, we're already seeing the effects of that with the coral reefs. So they are some of the most sensitive to ocean acidification, which is a component of warming and extra CO2 in the atmosphere. And so we saw it at an event at the Permian-Triassic boundary in particular. And that's very similar to what we're seeing today.

VERN STEFANIC: So what happens for us today? What can we be doing?

KRISTIN BERGMANN: I think thinking about the situation we're in now with hope is important, because obviously, over the last decades-- I mean, I remember watching An Inconvenient Truth 10 years ago. It's easy to do nothing. It's easy to think about the problem is too big and too intractable. But I think it's really important that we both decrease our CO2 output and think about ways to sequester CO2. All of the estimates suggest that we have to do both. And that it's not one or the other that's going to be the solution.

And so one of the things that I think is really interesting about my research is that it gave me a different way to think about a solution and to think about carbonates and how they sit within the climate system, because they store so much CO2 in carbonate rocks across the planet, we do. And so the earth has created this reservoir of CO2 that is locked up, that is hard to access, that doesn't affect how the ocean and the atmosphere breathe every year, or on even longer timescales and annual timescales.

And so it's really put away. It can't change the climate over short timescales. And I think that's what we would want in that solution. We'd want something like that. And you think in particular, thinking about carbonates that are precipitated by organisms, because it turns out biology is really good at it's job. It had millions of years to figure out how to do things. And so these organisms figured out how to do carbonate chemistry really well and make their shells and make carbonate platforms. And I think that is something we can learn from to help us take CO2 out of the atmosphere.

VERN STEFANIC: How did you get the opportunity to devote so much time and energy to this? Because sometimes people might have this, I have a great idea, and then that's as far as it goes. You actually had the opportunity to consider this and then to do research. Is that right? How did that happen?

KRISTIN BERGMANN: Sure. I've been lucky for many years. I feel like I've been working slowly on this topic of Earth's long term climate since I started my PhD or soon after starting my PhD. And so the things that have allowed me the time to devote to this are great advisors at Caltech, great support from companies, like Petroleum Development Oman. Now that I run my own lab, the students and postdocs that have signed on to help me tackle this project and this question and have chosen to make it a team effort with me. I think all of that has allowed me the space to think about this in a different way. And I think we have.

VERN STEFANIC: Good. You say you're running your own lab. How did that happen? I know, but tell the rest of us how that happened.

KRISTIN BERGMANN: Yeah, so when I was finishing up at Caltech, I got a job offer from MIT. And that has allowed me the space to be creative and to try to tackle this problem that might appear too big or maybe nobody even saw it as a problem. No, I don't think that's true, because Earth's climate system-- or the counter opposing Earth's seawater evolution through time has been debated for decades. And we haven't made progress.


KRISTIN BERGMANN: That's how I got the opportunity.

VERN STEFANIC: And what kind of response have you received so far for the work that you're doing?

KRISTIN BERGMANN: Yeah, I think in general that I've gotten a lot of support from other scientists. I think that people who study carbonates like thinking that-- some of it makes intuitive sense. And I think that some of it also connects some dots that were in the literature about patterns in carbonate sedimentation and the potential importance of evolutionary events. So I think that those scientists have been really supportive. I think that for people who study Earth's climate system, I'm a little bit outside of the range that people often think about climate, apart from modeling and trying to model snowball Earth events, in terms of building records. We've done a lot of work to build recent records, especially drilling deep ocean sediments and things like that or drilling ice cores. And it's just saw this question of can we even do it in the past that I think has stopped us.

VERN STEFANIC: Which is really fascinating, and again, as we started, there are people who-- there's a lot of scientists who've said that what's missing from our discussion now is the science of what happened. So instead of screaming that we need more science, you're actually out doing it.

KRISTIN BERGMANN: Yeah. [LAUGHS] I'm trying. Because I think we can learn from it. Just like they're saying, I think that there are things to be learned about studying the science of climate change.

VERN STEFANIC: So how many people are helping you in this project?

KRISTIN BERGMANN: Yeah, so I have a phenomenal group that makes going to work a great experience. So there are three grad students currently that are primarily advised by me at MIT and then two others who have worked in the lab through the years. I also love welcoming undergraduates into the group. And so I've had four or five undergraduates spend some time in the lab. And then I have three postdocs, who have come on over the last few years. So every year usually one or two people join the group and so we've slowly grown to be about 10 people.

VERN STEFANIC: Oh, good. Oh, good. Then you get to rest for at least an hour a day.

KRISTIN BERGMANN: Yeah, that's right. [LAUGHS]

VERN STEFANIC: Because I don't know how do you do all the things you do. Let me ask you-- and this is not a snarky question at all-- but I'm just wondering. You get support from the school, support from other geoscientists. Has the public slash politicians figured out what you're doing and what you may be contributing to the discourse?



KRISTIN BERGMANN: But if anybody would like to talk to me, I'm happy to have a conversation.

VERN STEFANIC: Well, is that something-- of course, your distinguished lecture for AAPG is going to get a lot of that science out. Are there other initiatives that are going on involving MIT or anybody that they're thinking about maybe pushing this out and throwing a little bit of a spotlight on your work?

KRISTIN BERGMANN: Certainly, I do try to have a spotlight on my work and what I think about with the public. But primarily, I do it through the people that I like working with, who I feel like are really mold-able. And so we do a lot with middle schoolers still. So there are a couple of middle schools in the Boston area who I regularly work, either to visit the classrooms, to actually host them at MIT. I've organized field trip out to look at the local geology at the end of every school year for the last few years. So I am trying to make the work about Earth's climate in deep time more accessible, but perhaps I am targeting the next generation.

VERN STEFANIC: Right, which by the way, I think is pretty smart. And that's what people have been saying is that they are the future, right? And so we should be talking to them. So help me with something. When a person gets to know a little bit more about you and reads your background and your approach and all the things you're doing, it's just kind of incredible to me that you have a lot of duality in your life. You're doing this amazing research. You also like being out in the field. You also like teaching. Then you also clearly in your research like still learning, too. There's still a lot that's still out there. And I guess what I'm curious about is the way you balance all that in your life, if there's different aspects that you recognize as being kind of most important to you.

KRISTIN BERGMANN: Yeah, that's interesting. What I say is important? Because I agree with you that I am a generalist that operates in different spheres. And that actually the work that I do with outreach or with teaching informs on my research. My research informs on my teaching. I integrate those. And similarly with advising. I think sometimes my research group, they might be working on components of this vision I have. And so I think they always appreciate it when we have a big picture conversation about how I see some of the connections. And so then they can even build those stronger amongst themselves.

So in terms of importance, I think balance is important, right? Because I wouldn't want to ignore teaching or outreach as a component of what I spend time on every day, just like I wouldn't want to ignore this aspect of field work. I think that without grounding ourselves in the reality of the rocks, then it's easy to say anything we want, right? But it's really important to go and make the observations in the field to then inform how we interpret the geochemical measurements we make, the models that we build.

VERN STEFANIC: And I know the way that you talk about your field of work how important that is to you. I'm curious. So you say once upon a time, you had no idea that you would wind up where you are now.


VERN STEFANIC: So with that in mind, the next question is going to be--

--well how the heck do I know? But your aspirations, so where do you see things going? And maybe part of that is the timeline that you're on right now.

KRISTIN BERGMANN: Yeah, so right now I'm an assistant professor. So I am going through a tenure process at MIT. and I think that is continuing to allow me to think big, to ask questions about how to answer things that I would love to know, like the importance of some key event in our history, like the evolution of planktonic calcifying organisms. How do we capture how important it was on the Earth's system?

VERN STEFANIC: That's pretty big.

KRISTIN BERGMANN: And so I think in the future just continuing to use a balance of fieldwork and lab work. I love adding new lab observations, especially at the micro scale, so I'm really excited about some of the synchrotron-based work that we've been doing. Going to these big government facilities that are supported and support lots of scientists, I think has been a really great way to continue to push observations at the smaller scale and smaller scale, so that I end up making observations from the microscopic scale all the way to the outcrop or even, I guess, global scale and thinking about how those things put together. So I would like to still do that.

VERN STEFANIC: Let me ask you one last question. You talked about the possibility of-- I think you said that there's reason that we can have hope. There's reason for something good. So could you just talk briefly about why, in a world that sometimes seems polarized and at odds, even over science, even over what this means in our life, where do you see the hope?

KRISTIN BERGMANN: Yeah. So I see the hope in a few things. I see the hope in passionate scientists who are working on climate change. I see the hope in everyday people who are experiencing climate change and recognizing that something is not right in our system and that things have changed over their lifetime. And I see the hope in companies, companies like the petroleum industry, because they have what I view as the right set of skills. And I think that they have the skills from engineering, drilling, thinking about carbonates, thinking about carbon to put some of the pieces together, to do some of the big, large-scale carbon sequestration that we'll probably need to do in the very near term.

And so to me, it feels like we've got the potential to capitalize change. And we have to do that quickly. But I would much prefer to think that we can drive the change that we need to make, as opposed to do what we've done the last 10, 20, 30 years that we've known this is coming. That instead we act on our fear and we don't sit and think that the problem's too big to solve.

VERN STEFANIC: Kristen, thank you for that. And here's hoping that's exactly what happens.

KRISTIN BERGMANN: All right. Thank you so much.

VERN STEFANIC: And thank you for joining us. We've been talking today to Kristin Bergmann, assistant professor of MIT's department of Earth, Atmospheric, and Planetary Sciences in Cambridge, Massachusetts and holder of prestigious Packard Fellowship in Science and Engineering. Be sure to check out her lecture at AAPG.org.

And watch this space for more AAPG podcasts that will cover a variety of important subjects and intriguing people, including our ongoing Digging Deeper series, featuring conversations with this year's AAPG distinguished lecturers. All AAPG podcast are available through the AAPG website or your favorite podcast platform-- iTunes, Spotify, Stitcher, Google. Whatever your preference, we're there. The Distinguished Lecture Program is a jointly operated program by AAPG and the AAPG foundation. We hope you'll take a moment soon to check out the AAPG foundation to learn about how you can be part of ensuring the future of geosciences. For now, thanks for listening.

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