Peter Clark Oral History Interview, December 15, 2017

ELIZABETH THORLEY: Today is December 15, 2017. I'm here with Dr. Peter Clark, distinguished professor of the College of Earth, Ocean, and Atmospheric Sciences. We're at the Valley Library. Today we're going to talk about his research and global warming, but I'd like to begin with your background. Where were you born?

PETER CLARK: I was born in Connecticut.

ET: Is that where you grew up?

PC: I lived there the first six years of my life and then we moved to California.

ET: What did your parents do?

PC: My father was a schoolteacher and my mom was mostly an at-home mother but also a schoolteacher.

ET: Did you have early interests in science or the outdoors?

PC: Not in science but my interest in the outdoors began when we moved to California and that's when I started doing a lot of backpacking and things like that.

ET: What part of California?

PC: We lived near Carpinteria, which is south of Santa Barbara.

ET: Okay.

PC: Which has been in the news recently because that's where the big wildfires have been.

ET: What was your early school experience like?

PC: Run of the mill. Elementary school, nothing unusual.

ET: Did you have anyone advising you to go to university? Was there an expectation to do so?

PC: Expectation only in the sense that my family has a long history in academics and so my father was a teacher at a prep school it's called, which is private school which usually prepares students for, historically, prepares students for colleges and then on my father's side we have family that goes back at universities for generations and so forth.

ET: What influenced your decision to go to St. Lawrence University?

PC: Because that's where the university was where a bunch of my family had been, played a role from the very beginning of the university where my great, great grandfather or great grandfather was the first president of the university.

ET: You end up getting a bachelor's of science?

PC: I did, yeah.

ET: How did you end up choosing to go that route?

PC: I started at St. Lawrence as an English major, because in high school I developed a big interest in reading and literature and so forth. Then I started as an English major with a leaning towards journalism but my freshman year I had a couple of friends who were geology majors and they suggested I take an intro to geology class which I needed to take a science course. I took that class. I was immediately taken by the slides of mountains where I had done a lot of 00:03:00backpacking prior to that and so that's what first captured my interest in geology.

ET: Did you do any undergraduate research?

PC: I did. I stayed as a double major in English and geology for a couple years thinking I might go into textbook publishing, things like that, where I could combine the two and then just went full out geology after my junior year and then my senior year I did a senior thesis and did research for that.

ET: What influenced your decision to pursue graduate studies?

PC: It was just the natural thing that a lot of my friends were doing, fellow majors they all were moving on to graduate school and I just followed my interests as well and thought this is what I was really interested in doing and so I wanted to pursue it at the next level.

ET: Did you anticipate pursuing a Ph.D.?

PC: I didn't really have any long-term plans. I just kept pursuing my interests. So it wasn't in my long-term plans but it was just something I continued to follow that course.

ET: You ended up at the University of Waterloo in Ontario?

PC: For my masters. I went to Waterloo for my masters. I applied to several schools and I visited them and my visit at Waterloo was very successful and they were able to put out a really nice show for me and also the person I applied to work with was somebody I really admired, already knew his work and so it was an easy decision to go there.

ET: Did it feel any different living north of the border?

PC: Well, St. Lawrence is within 15 miles of the border so we were in Canada frequently anyway, just crossing over to Montreal or Ottawa or something.

So, it didn't really feel any different being across the border at all.

ET: You studied late Quaternary History ET:ET:_ New York, is that right?

PC: Did your homework, yeah. So my master's thesis took me back to St. Lawrence University in the St. Lawrence Valley and so I studied the glacial history of that area.

ET: Were you particularly drawn to the glacial history or was that research that was available to you at that time?

PC: It was a combination of really liking the area north of the Adirondacks in the St. Lawrence Valley and the research question was pretty interesting as well.

ET: Did you teach as a master's student?

PC: I did a little bit of teaching assistantships, teaching as a teaching assistant but not very much. Mostly I was on a research assistantship.

ET: Did you enjoy that aspect of it?

PC: I didn't really get that much flavor for it, or bunch of experience at it so 00:06:00I wasn't quite sure.

ET: Then you decided to pursue a Ph.D. at the end of your masters?

PC: Again, I was just following my interests and I was getting more and more interest in the field. My initial interests in geology as a freshman at St. Lawrence had been in the mountains which there the major discussion was on the role of glaciers had had in the formation of the landscapes that we've seen in the mountains. That sparked my interest in glaciers right from the beginning, so that's what I continued to pursue both at my masters and then on to the next level a Ph.D. was following that interest in glaciers.

ET: You completed that at the University of Colorado?

PC: I did my Ph.D. at the University of Colorado through the geological sciences department but specifically at a separate research facility called the Institute of Arctic and Alpine Research. Again, while at St. Lawrence one of my student jobs had been as the science librarian. They have a small science library and 00:07:00mine was the librarian there during certain hours of the day and while there I would basically browse the new journals as they were coming in and being ready to be shelved, so I'd be browsing through the geology journals and specifically the ones that were related to glacier studies. One of the journals was called Arctic and Alpine Research, which was produced out of this place where I ended up for my Ph.D. and right at that point I was intrigued by the arctic from looking at that journal and the photographs and so forth and I became very familiar with that topic so then I was ready to go there for my Ph.D. for sure.

ET: What was the culture of that research group like?

PC: It was outstanding. It was at the time I would say among if not the best research groups for doing the kind of stuff I was doing, both with regard to the 00:08:00faculty and the graduate students.

ET: How did you like life in Boulder?

PC: Boulder was good, less expensive than it is now, less crowded than it is now. Still, it was a nice place and I always was a mountain person and so having the Rocky Mountains right there was nice.

ET: You ended up doing research on the glacial history of southern Baffin Island?

PC: I started on Baffin Island in the Canadian Arctic for my Ph.D. but then after one field season up there I talked to my advisor and again harking back to my days in the science library looking at the journals the articles that had always struck my interest was in northern Labrador, had to do with northern Labrador. In northern Labrador there's a mountain range called the Torngat Mountains and Torngat is an Inuit name for the Lord of Evil Wind. I wasn't quite 00:09:00sure why that was the case at the time, but anyways I loved the landscapes and was really interested in the studies that had been going on and so talking to my Ph.D. advisor I convinced him to move just south of southern Baffin to the northern Labrador and work in the Torngat Mountains and that's where my most of my Ph.D. work was doing in the Torngat Mountains. That's where I learned why he's called the Lord of the Evil Wind, because it's an extremely windy place.

ET: So, it sounds like you got to visit there for data collection? Can you talk about that experience?

PC: Working the arctic is pretty interesting, because it's very remote. In Baffin I flew into a small Inuit village and then hired a local Inuit and I had a field assistant with me, a friend from St. Lawrence came along to accompany me in the field because you don't want to go alone.

We hired a local Inuit person to take us by his canoe, which had an onboard motor, down the fjord to the coastline, the main coastline of southern Baffin. He dropped us off there for two weeks and then picked us up two weeks later. It was pretty remarkable that he did that. In Labrador to get to the Torngat Mountains basically you have to fly in by a float plane and so we would fly in from either Schefferville, Quebec, or another place south of Ungava Bay called Kangiqsualujjuaq, or, excuse me, Kuururjuaq, so we would from either of those two places fly in by float plane and with six weeks of food and backpacks and they would drop us off and then they'd pick us up 6 weeks later and then we'd do our fieldwork while we were up there, just the two of us.

ET: That sounds pretty amazing landscape to be in.

PC: Yeah.

ET: Did you teach as a Ph.D.?

PC: I did not. I was always on a research assistantship.

ET: After you completed your Ph.D. you ended up teaching at the University of Illinois in Chicago?

PC: Mm-hmm [yes].

ET: How did you end up at that institution and what was your impression or sense of it?

PC: Well, I was still six months or nearly a year away from finishing my Ph.D., but I thought it's time to start applying for jobs. I applied for the job in Chicago and it was in a field called Sedimentology, which I was remotely doing but mostly I was doing glacier stuff, but I was invited to interview and I gave a job talk that was glacier sedimentology related and they ended up hiring me. Before I was done with my Ph.D., even, so they hired me in January and I didn't defend my thesis for another 6 months. The first six months I was there I was 00:12:00still working on my Ph.D. and teaching. The department chair at the time had been a St. Lawrence University alum as well, geology alum from before my time, I think he told me that he knew that St. Lawrence produced a lot of good geologists and that sort of gave him some good confidence about my abilities, even just as an undergrad level. That was my first job, just kind of lucked out that the first job I applied for I got a job. It was a nice place to start.

ET: I'm assuming that you taught while you were there?

PC: I did teach while I was there. I had the usual teaching research service type of tenure-track assistant professor position, yep.

ET: What did you think of living in Chicago?

PC: Chicago's a great city. It's a really great city, culturally fantastic. It's 00:13:00culturally diverse. Lots of different aspects to it to take advantage of. You cross a street and you're in an entirely different culture. There's little Italy and this ethnicity and this ethnicity and this ethnicity, and just crossed. They're very much divided in that regard but you could sample a broad range of diversity and the other thing about Chicago is it's one of the most beautiful cities in terms of its architecture. It's spectacular. I really enjoyed living there for the time I was there.

ET: Not too many mountains nearby.

PC: At the time Coors beer had a commercial specifically aimed at Chicago buyers which would show the city skyline. It's right on Lake Michigan. There's Lake Michigan and then the city skyline and then as the ad's progressing the Rocky 00:14:00Mountains would pop up behind the skyline. I said that's the only thing missing from here is the mountains. Yep.

ET: What influenced your decision to move to Oregon and work at Oregon State?

PC: While at Chicago I was happy. I had gotten the job there and so forth, but it did not have a Ph.D. program and although I love Chicago I was not a city person and it was out in the middle of Illinois, so there are several things about it that I was happy there but was thinking of moving on. I started looking around for other jobs and a job opened up here at Oregon State that I applied for and so I got the interview. Ended up with the job as well.

ET: What were your initial impressions of Corvallis?

PC: You know, nice small town. Oregon, all the good things that comes with 00:15:00Oregon. It was good.

ET: Who were people important to getting you settled in?

PC: Let's see, you mean in terms of colleagues? About the time I was hired they were as is often the case with universities there's just through demographics there's a certain age group that's hired all around the same time and then as they age and move on and eventually they're approaching retirement and so then they have to think about replacing them. I came in on one of those changeover times that several people had retired just before I got there. Others were within a certain numbers of years of retiring, so they started hiring several young assistant professors. I came in at the same time as three or four other assistant professors. I was pretty much the last of that hiring group. They'd 00:16:00been my colleagues ever since, although they're now starting to retire as well. We're going through the same cycle, basically our slug moving forward and now a younger cohort's coming in. They were good colleagues and then the senior faculty were very supportive as well.

ET: When you arrived you were in the Department of Geosciences, is that correct?

PC: AT the time it was the Department of Geology.

ET: Okay.

PC: After so many years there was a Department of Geology and a Department of Geography. We were all in the same building, Wilkinson Hall, but I don't remember the circumstances that led to it but the university was looking for ways to streamline things, so they recommended that we either merge or that geography moves to University of Oregon. The decision was to merge into Geosciences.

ET: You continued on as a teacher at Oregon State?

PC: Mm-hmm [yes].

ET: How has your role as a teacher evolved over the years?

PC: I'd say it's something that although I didn't have very much experience with in graduate school when I started teaching I really loved it and so for example the first term that I taught at Chicago after that first term I taught at Chicago I received the university's wide teaching award for that year. I must have been doing something right. Then I've continued to just really enjoy teaching and work hard at doing it well and I've continued to be recognized for my teaching as well.

ET: Do you teach undergraduate and graduate students?

PC: I teach a range from introductory courses to graduate courses, yep.

ET: Moving more into your research, can you talk about how tools to date ice cores or I guess tools that you've used through your research have evolved 00:18:00through your career and maybe touch on tools you used for predictive climate change modeling?

PC: I am largely a if you would call a field-based geologist but I'm also sort of a synthesizer and then through those two areas of doing the fieldwork and also looking at the bigger picture through the synthesizing come up with questions and so forth that really need models to investigate. So, then will reach out to people who run the models. I'm not a modeler, but I recognize a good research question and I approach modelers with that question and say would 00:19:00you like to collaborate on this? That's kind of how my career has gone is really especially once I moved here to Oregon is that sort of collaborative work among colleagues in different disciplines, where it be modeling or different aspects of climate change that I do but that I'm not an expert in but see an interesting question will reach out and ask colleagues to collaborate on. So, what's evolved really is some of the methods we can now use that weren't available at the time to develop the timing of events which is critical in terms of understanding climate change because you want to know when things change and what that might mean about climate change and then the models themselves that I work with that are used by people I work with of a variety of sorts have also evolved and improved with time and the diversity of models available as well.

ET: When did your interest in anthropogenic climate change start?

PC: I'd only been interest in climate change in general had always been out there in terms of general interest for me and even when I was at Colorado a research scientist there was pretty much thinking about and been involved with some of the work in '70s and '80s on thinking about carbon dioxide emissions in the future and forth and ice sheet stability. We'd talk a lot about that. But again I'd always been working in the geologic time that's already passed but as the evidence if you will of global warming became stronger and its impacts on 00:21:00various things that I was studying that had happened in the past, the evidence that those things were changing then it became clear that what I was studying actually provided important context of how the system had changed in the past and what that might mean and inform us about in terms of the future. That corollary of using the past to help understand the future was evolving through the time I was coming forward and has become a mantra but nevertheless there are issues with using past climate change as a direct analog for the future. It's not a direct analog. It's an example of how the system behaves but what was causing the system to change in the past is not necessarily the same thing that is causing the system to change in the future. How things change in the future will not necessarily change in the same way because what's causing the change is different.

But again we continued to develop records of climate change, ice sheets, global climate, global temperatures, sea level, and so forth and that all nevertheless were telling us something about the system and provided if nothing else context for how sensitive the system is to a forcing and so forth and as my work broadened I became more involved in national and international efforts to think about future change. I was involved with the U.S. Global Climate Change Report on abrupt climate change and the potential for it occuring in the future a few years ago and then in 2012 I was invited to be involved with the intergovernmental panel on climate change as the coordinating lead author for the chapter on sea level change. It's just kind of continued to evolve in terms of my interest now moving more into the future, in fact, even though I'm a field 00:23:00geologist my thinking is more about questions and thoughts about what's going to happen in the future and again working with modelers to ask those questions.

ET: So you kind of touched on this, but do you think you have a unique perspective or framing of climate change given your work on geologic time scales compared to say the average citizen?

PC: Well, compared to the average citizen meaning?

ET: Someone who doesn't think as frequently about large-scale trends with the earth's history.

PC: Sure, so I think probably the average citizen and so forth will receive information that kinds of limited or just bits of information from which they're 00:24:00trying to understand what's going on. A lot of the information that they're receiving is coming from we'll just say climate denialists and conservatives and so forth who don't believe in climate change or who don't think it's an important issue. One of the things that's often said among that group is that well, climate change has always changed, climate has always changed. What we're seeing now is this natural change that the earth has always experienced and that's where it's obviously a fundamentally wrong argument but also it's a point where with experience of how the earth's climate has changed in the past you can address that by saying, yes, it has changed in the past but what's happening now is very different from that.

ET: You referenced ice sheets. When did you start incorporating ice sheet as a part of your research and can you talk about how they play a role in the global climate?

PC: Well, basically from the beginning of undergrad my research in glacial history has largely been on ice sheets, even though my initial interest in glacial geology was from mountainous landscapes that had been largely formed by glaciers, the small things. My research interests were in the line of ice sheets, so that was right from the beginning. It devolved again from thinking about them in terms of past history of ice sheets from small scale like the St. Lawrence Valley and in the case of Torngat Mountains that was all getting at the question of what was the ice sheet doing in those particular regions to starting to think more broadly when I got to Chicago about the whole ice sheet that affected North America at the time. Then thinking about how those ice sheets had 00:26:00influenced climate when they existed. Then also how they played a role in the sea level changes that had occurred and so in terms of how ice sheets influence climate, they do so in a variety of ways but the most important ways are first they have a large white surface and the importance of that is that that white surface is highly reflective of sunlight and that's something called albedo, which is a measure of how reflective the surface is. If you take for example northern North America today it's largely trees and rocks and so forth which are fairly dark. Now just imagine covering that with a big white mask, whether it's snow like we have in the winter or permanently with an ice sheet. Now you've permanently changed the albedo of that part of the earth's surface to be much more reflective and then what that does is the earth is absorbing less solar 00:27:00radiation now because it's being reflected and that causes cooling just through the albedo effect. Then the ice sheets are not flat like a snow layer, they're very large and thick and high. The ice sheets over North America were on the scale of the ice sheet of Antarctica today which means they were on the order of up to 4,000 meters high or 15,000 feet high at their highest elevation. Essentially you're taking Canada again today, which is largely flat east of the Rocky Mountains at sea level and you're raising that elevation up to about 10,000 feet and when an ice sheet grows, 10-15,000 feet.

The importance of that effect is on the way that it interacts with the atmosphere. As the atmosphere is flow, the large Jetstream and major atmospheric circulation encounters the ice sheet it's going to be deflected by the ice sheet 00:28:00and influenced by the present physical size of the ice sheet. That deflection of the atmospheric circulation affects climate. It's the albedo effect and the elevation effect of ice sheets that affects the atmosphere. Then ice sheets are also a big reservoir of fresh water, so they are frozen water. When that water melts, when that ice melts, it runs off the continent and ends up going in the ocean. Most of the northern hemisphere ice sheets in North America and Eurasia most of their drainage was into the North Atlantic, so you have this fresh water coming into the North Atlantic which is much greater than today, for example. At times those ice sheets release fresh water in greater amounts than at other times. The importance of that fresh water going into the North Atlantic is it affects the circulation of the North Atlantic Ocean. That circulation of the North Atlantic Ocean has global effects. If you perturb that circulation, it 00:29:00actually perturbs climate elsewhere around the world just from having done that. They influence the climate through the ocean circulation as well. The atmosphere and the ocean are important in that regard.

ET: Can you talk about the significance of Greenland ice sheet melting since that comes up in the context of climate change?

PC: So, again, two ways that, well, another factor I didn't talk about in terms of ice sheets, of course, is their effect on sea level. Where the moisture comes that goes into an ice sheet is coming out of the ocean ultimately. If you grow an ice sheet, that means sea level has to fall. Melt an ice sheet sea levels rise. In the case of Greenland, it's a small ice sheet by comparison to Antarctica today, for example, it's about a tenth of the size of Antarctica compared to the North American ice sheets, it's, again, about a tenth of the size of that.

It's relatively small, but nevertheless if you were to melt all of Antarctica 00:30:00today it was cause global sea level rise on average to rise by about 25 feet. That's still a significant amount of water that's frozen up in that ice sheet. It would have a big impact on sea level, global sea level. At the same time because its location is in the north Atlantic region, then, and this has been subject to a lot of research and this is where some of the paleo work that I do has been relevant to thinking about this question-when you melt the Greenland ice sheet and that freshwater goes in the North Atlantic, is it going to affect the North Atlantic ocean circulation? which has global effects again and so that's been a big area of research. Those are the two major ways in which melt in Greenland could potentially affect, or will affect climate and society is through sea level and ocean circulation.

ET: Earlier you referenced abrupt climate change. Can you explain how that 00:31:00differs from say non-abrupt climate change?

PC: We're usually pretty careful to define what we mean by abrupt. The standard definition is the change in climate occurs much more quickly than whatever the process is that's causing the climate to change. You can imagine that you're taking this glass of water and my first is causing the position of that glass to change. It's changing slowly and moving at the same change and at the same rate that I'm pushing on it. Eventually it hits the edge of the table. If I continue to pushing at the same rate, it falls over. So, it falls abruptly. The rate in which it falls is much faster at the rate in which it was being pushed. The same is true for climate, that you're pushing on the climate system with change in carbon dioxide in the atmosphere or change in solar radiation or what have you. The response to the system is to basically be what's called non-linear or have a 00:32:00tipping point type of thing where it changes much more quickly than you would have expected from the amount that it was being pushed.

ET: You referenced your involvement with the IPCC?

PC: Mm-hmm [yes].

ET: You've been a coordinating lead author. Maybe you could talk a little more about how you got involved in that and what your experience has been like as an author.

PC: The way you get involved is by being nominated and so for the last assessment, so prior to the call for nominations, the last assessment, they're called assessments, and so the last one was the fifth assessment. Prior to that I had been working with a couple of colleagues, one at NASA and one at New York University on organizing a workshop that was requested by the National Science 00:33:00Foundation to bring together experts to put together a working paper, or white paper for the NSF in terms of helping prioritize their funding opportunities with regard to understanding ice sheets today and what we need to do better to understand them better. We had that workshop and so one of those colleagues that I worked with from NASA nominated me for the IPCC and he asked if I'd be willing to be nominated. I said sure. I was pretty surprised first that given my paleo background a lot of my research at that point was on sea level but it was paleo sea level. A lot of my other research had been on paleo climate from other ocean changes and ice sheets and so forth. They have a whole change on paleo climate, so I thought if anything I'm going to be with the paleo climate chapter, but I 00:34:00ended up being selected for the coordinating lead author for the sea level chapter. You never know how those things, you know how the decisions are made-the decisions are made by the committees that make those decisions but how I was actually selected by them to be in that particular position I'm not quite sure. I think they understood that the paleo perspective for sea level was important and I think they saw my record as being broad and interdisciplinary and again this synthesis type of thing that I could play a role and I think that given the activities I'd been playing at the national level that also was a good fit. But it was a surprise.

ET: It seems like from how you've talked about it they're inherently intertwined, but the IPCC just breaks it down into sections within the report or working groups?

PC: Breaks down?

ET: The sea level and paleo climate.

PC: Right. They have chapters and so there's three working groups.

The working group one that I was involved with is the physical basis 00:35:00understanding of climate change. Understanding the physical basis for climate change. The others are mitigation and adaptation and impacts and so forth, the other working groups. This is working at the physical basis for climate, and so there will be a chapter on the atmosphere, observations of the atmosphere, that we have. There will be one on observations of the ocean. There will be one on biology chemical cycles. There will be one on radiative forcing and so forth. There was one on paleo climate because again the paleo provides this understanding about how the system behaves. Now, in the previous assessment report, the fourth one, they did not have a separate chapter for sea level which was the first time because the previous three assessments, the first three assessments did have one for sea level. By the time of the fourth one they felt that they understood sea level pretty well and the basic conclusion is that sea 00:36:00level is going to rise but it's going to be largely due to warming of the ocean which causes the ocean waters to expand but that we didn't really have much to worry about in terms of ice sheets and we understand Greenland pretty well and Antartica was pretty much going to be inert. It wasn't going to really do much in the next few centuries and so not much of a cause of concern and so they relegated sea level down to within a subsection of a chapter on projections. Rather than entire chapter on sea level in terms of what's going to happen to it just relegate it to a little discussion about it in the general chapter on projections which included projection of global temperature and precipitation and everything else. But just at basically at the time that the report was coming close the fourth assessment report was reaching completion, the process lasts several years and it goes through several stages of several versions of 00:37:00each chapter that get reviewed and commented on and revised and so forth. When they're approaching the end of that process some things started to happen to the Antarctica sheet that basically made people realize that they were probably really wrong about thinking that the Antarctica ice sheet was going to be inert and not really subject to change.

In fact it could change much more sooner, much more rapidly than we had thought. But it had happened at just such a point in the progress of that preparation of report that the way IPCC works is they assess existing literature. They don't do research. They assess the literature and look at what the literature is saying about our understanding of climate change. There was no literature on what was going on in Antarctica. It was just happening and so they didn't have anything to assess it with and that's what the process involves is assessment. They had to acknowledge the fact that they couldn't take that information in terms of 00:38:00using it for projections and when that was published basically a lot of people pointed to the sea level part of it and said that the IPCC had failed because clearly Antarctica was going to be an important player and essentially IPCC had punted. They had not really said much about it, but the point is they couldn't say anything about it because there wasn't anything published on it. That's the process. So, sea level was elevated to its own chapter again and it was probably the most important chapter with regard to getting it right because the other aspects certainly there had been progress, substantial progress in our understanding about all the other things that were going on. But it was relatively gradual, whereas sea level here was something we really need to readdress our understanding of and get it right this time because essentially 00:39:00they totally got Antarctica wrong previously. When they realized that it was too late to do anything about it. We were faced with then this pretty high priority thing about dealing with sea level. So, that was pretty exciting to be amidst all of that and nevertheless the research that was being done and papers being published, it's a graduate process to do research and get papers published and so forth so the literature we had to work with up to the point of basically the final deadline in May of 2013 or even earlier in March of 2013 with the final report being released in September 2013 was still in its early stages.

The work that's come out since then has moved the field along, especially with 00:40:00regarding to Antarctica and Greenland to some extent, move the field along quite a bit since then. But it turns out that even with what we had to work with, what has since come out has basically in my opinion just supported what we were able to conclude from the existing literature at the time. I feel very good about that. In other words, while we provided information-although people don't always know how to read these IPCC reports correctly, and that's not for a lack of us making it transparent about what we're saying it's just people don't read it carefully enough, but I don't think we've learned anything since then that are going to lead us to be in for big surprises.

ET: So, in comparing writing an IPCC report as opposed to your scientific research, do you feel like you're writing for a different audience? It sounds 00:41:00like it's a different process.

PC: It's basically a-it's not just a review paper, but think of it most closely like writing a review paper because you're looking at the existing literature rather than collecting new data and interpreting those data and coming up with a new story. You are reviewing the literature, but you're critically reviewing it and critically assessing it and you're assessing the literature for how robust the conclusions are and what the nature of the evidence is and how robust that evidence is and how much consensus there is in the literature with regard to 00:42:00certain conclusions. You might have ten papers all basically reaching a very similar conclusion and one paper that's kind of a flyer. It's very, very different. Are you going to give that equal weight to what the majority of the scientific evidence is pointing towards? The answer would be no. You're going to 00:43:00go more with the consensus. To some extent IPCC has been criticized for this consensus-type of approach, but we address those other studies but then based on the majority of the evidence conclude that it's more unlikely that that will be the case and more likely that this will be the case. And we put it in this likelihood type of thing. I don't remember exactly where I started from this-

ET: In terms of who you're writing for.

PC: So, who I'm writing for. It's reviewing the literature but critically reviewing it, critically assessing it. Then in terms of the style of the writing and so forth there's no difference in that regard. There are specific things that you need to make sure are covered for the audience and those are things 00:44:00like certain language that has to be used to reflect the nature of your findings, but otherwise it's not that much different.

ET: Do you anticipate being involved in future assessment reports?

PC: They put out a call for nominations for the sixth assessment report and they will be making those selections starting I think in February, so we'll see. I'd be interested in doing it again, probably not at the coordinating lead author, though.

ET: It sounds like a lot of work.

PC: Yeah, the structure is that each chapter has usually two coordinating lead authors and they basically coordinate the chapter and then there will be anywhere 10-15 lead authors and they will have been selected because of their specialty to cover various aspects of whatever the subject is. Then they will write various sections of the chapter and the coordinating lead authors will 00:45:00also contribute something in the writing as well, but they will more likely be coordinating things to make sure everything is consistent and we're evaluating thousands and thousands of research papers and so it's really important that what we end up with is consistent within the chapter and consistent with other chapters in the report and consistent with the other working groups. Because this is the major instrument used for policy at the international level. Consistency is critical. Coordinating authors are really clued in to making sure everything is correct and consistent, and that takes a lot of work.

ET: How did you get involved with the U.S. Climate Change Science Program?

PC: Regarding this abrupt climate change report I was involved with, again, I was just asked to be involved with that.

ET: How does that?

PC: I'd been writing papers about abrupt climate change prior to that, so I was on the radar, I suspect.

ET: How does that compare with say working with the IPCC? This is a national, domestic-?

PC: Yeah, this is the, so the U.S. program puts out reports of various sorts. In this case there are a series of reports on typical studies. This was about climate change. They had one on other subjects. Then every so few years they release a national assessment. The national assessment is more parallel to an IPCC assessment but for the nation, but otherwise it parallels it with regard to the topics that they cover. These more specialty reports are IPCC-like in the sense of assessing the literature in terms of what the most robust evidence is and conclusions that you can draw from that are with regard to the subject. It's, again, in the mold of IPCC but just narrower. Although IPCC does that kind of typical thing as well as their major assessment reports they have special reports that they call them that they release every so often.

ET: Now I'm going to move to some broader climate change questions. What were your earlier conversations on climate change like and how have these dialogues shifted over time?

PC: So, with colleagues I think that in the earliest days so to speak in terms of as I was coming on the scene there was certainly a lot of discussion about it but not at the level of interest that it's certainly reached now and certainly not at the amount of the number of colleagues that exists now. When it was 00:47:00discussed it was more of well, maybe, maybe not, you know this was when I got into the game it was before IPCC even the first assessment report in 1990. There were very strong arguments about it before that certainly but still it was you know even those studies recognized that it wasn't so much the greenhouse effect that if we continue emitting carbon dioxide it's not going to have an impact, more of the question was has global warming started to occur yet? I think that was unfortunate that it kind of went in that direction because why are we 00:48:00debating whether or not it's happened this year or not? The major question is that as we continue to emit CO2 is that it's going to happen. But there's a lot of interest in trying to detect whether or not that signal of global warming had emerged yet in the temperature records. There's famous stories about people making those claims early on and so forth and that maybe diverted a lot of attention to that. I think in that regard the discussion was more like we don't really know yet if it's emerged but certainly if it continues it's going to become a problem. But the scale of the problem, the scope of the problem really hadn't yet either been addressed and that's when I think IPCC really made a huge impact was bringing that future impacts to broader recognition and understanding. As time has evolved and as more and more research has come along and has things have clearly started to change, it's become in my opinion pretty 00:49:00unequivocal that the signal has emerged and at the rate we're going that the impacts will be large. And I think that's pretty much agreed upon by most of my colleagues and as you read the reports studies of scientists who study this stuff who are bona fide legitimate climate scientists we're talking about 97% of the climate scientists all have that sort of opinion.

ET: Can you speak about the community of climate change researchers here at OSU and how the institution maybe facilitates that?

PC: Facilitates?

ET: The community or collaborative work?

PC: This is a really great university for studying not just climate change but global change that is closely aligned to climate change.

Global changes that are associated with climate change or a result of climate 00:50:00change. So, if you look at the biological sciences or forestry or engineering or economics or policy you know you can find really strong elements of interest and research in these aspects of climate change and its impacts on various aspects of society and implications for policy and economics and so forth. Much of the study of climate change strictly speaking is in the College of Earth, Ocean, and Atmospheric Sciences. Naturally, that's where those type of scientists reside and one of the reasons I'm still here at OSU is because I feel my colleagues here in this area of climate change are, the group we have and the variety of disciplines that they represent is outstanding and furthermore the collegiality 00:51:00among us and the interest in collaboration and so forth is really great. We have I think OSU has certainly one of the highest profile groups in the country, if not the world, with regard to the broad variety of disciplines covered and the expertise and so forth.

ET: How do you foresee coping with diminished funding to climate change during the Trump administration?

PC: Well, it's not clear to me that that's happened yet. There are certainly lots of concerns and there were right from the beginning that it would happen and I'm not sure that it's filtered down yet or maybe it's starting to but not in ways that I've directly seen. It's interesting, several of us independently 00:52:00got phone calls from a reporter at NPR a few weeks ago who they looked at the number of grants funded by NSF with climate change in them and found that those numbers have dropped significantly since the election. Of course they're wondering whether or not people are trying to either the funding's disappearing or people are trying to hide things and so forth. One of the major funding agencies or funding programs I go to at NSF is called climate change, so I know a colleague here at OSU remarked on that study. I just told him I haven't seen any sign of it. Another colleague here says he has seen it. I'd be curious to what he has seen. It could be just that but it's coming. It just hasn't really 00:53:00manifested itself yet. I think we still need to be very vigilant for that and concerned about that. It does take time for the federal process to work its way through the system. I think though that it is the way the government is designed is it's that we do have some strong voices who would speak out against that as much as possible from happening. We'll see.

ET: Based on your professional experience, I guess your personal experience as well, what policy changes would you like to see happen within the U.S.?

PC: To address the question of climate change?

ET: Right, right.

PC: Well, I think the policy changes are ones of you know doing everything possible to encourage investment and research and development in alternative 00:54:00sources of energy to reduce emissions but not just to reduce emissions. We can't just reduce emissions, we have to get emissions down to zero because the C02 problem, the carbon dioxide problem, and carbon dioxide is the primary just because of the amount that we release is the primary contributor to global warming of the various greenhouse gases. It's not the most potent greenhouse gas but it's the primary one because of the amount that is released. The C02 problem is first of all that it causes global warming but secondly that it stays up in the atmosphere for a long time, such that if we put in a pound o C02 today, which each of us easily does, that in 10,000 years we'll still have about 20% of that C02 left in the atmosphere. It just doesn't go away very quickly. Which means, the problem doesn't go away. If we reduce emissions we're still emitting and what we're emitting is still staying up there and is still affecting 00:55:00climate. We have to get to zero emissions and in fact preferably go to negative emissions, where we're actually taking C02 out of the atmosphere.

Now the reason for that is because the understanding of the impacts of global warming now is so well-understood and we're starting to see them express, but we're still really early in the game yet, but more and more we see those impacts affecting people's day to day living today. That will just simply increase in the future and the sooner we can do something about it then the less and less of that impact we will see in the future, not only in people's lives but on, well, directly on people's lives but through a variety of ways.

ET: What changes to public education could help Americans better understand climate change or possibly change to their behavior?

PC: Hmm. You know one thing that scientists are encouraged to do more often is 00:56:00get out and speak to the public in a way that the public understands and in a way that's not going to scare the public because you can talk about it in ways that are like so scary that a natural reaction is to throw their hands up in the air and say well, what can we possibly do? So you want to come prepared to talk about the nature of the problem and solutions to the problem and that message is getting more and more out there and I think it's just at the same there is a source of misinformation that's out there that's very, very active. The public are, it's well-known, are sort of stuck in a place of trying to understand and decide well, who's right? The other side will present it in such a way that it seems exactly as legitimate as coming from the more rational, scientific base 00:57:00and so I know just from talking to people who are not scientists that that's, that they're not understanding it or they're able to not appreciate it because they think well, so and so says it's not a problem. More and more of that education is needed at a grassroots level. It can't be top down. It's got to be grass roots.

ET: Are you hopeful about the future of the planet in the context of climate change?

PC: No.

ET: Alright, well, that concludes our interview.

PC: Okay good.

ET: Thank you for your participation.

PC: Thank you.

ET: I appreciate your time.

PC: Okay.