 Camille Parmesum, I'm a professor at the Marine Institute at Plymouth University. I work on the impacts of climate change on wildlife, and I do this both through doing enormous global meta-analyses of everything that has a dataset, but I also do my own field work on butterfly plant systems in Europe as well as in the Western USA. I started out as an evolutionary biologist and a behaviorist, and the reason I worked on butterfly plant systems was really because I'd tried working with primates, I'd tried working with honeybees, tried working with birds, and it's a lot of hard work, and I never got very much data, and then I spent a summer working with butterflies in the mountains of California, and basically they'd drip data, and within two weeks I had a single author paper as an undergraduate. So I thought, and they don't wake up till 10 o'clock and they go to bed at four, so it was just a really nice system in so many different ways, and they live in beautiful places, so that got me into doing the field work with the butterflies, but really for many years I was working on the basic evolution of diet, evolution of behavioral adaptations to different host plants. What got me into working on climate change was really a fluke of luck. So NASA put out a research funding program announcement for people to work on climate change, and it was mostly about doing remote sensing, ecosystems people looking at changes between differences between grasslands and forests, and at the very bottom they had one little sentence of this whole page describing what they wanted to fund that said, and were interested in responses of species. And I thought, I've been working for 10 years on this butterfly, the single species, Edus Czeck's butterfly, that everyone knows is incredibly sensitive to climate. So ever since Paul Ehrlich started working on it in the 1950s, his early work was actually documenting very strong responses of the populations to yearly climate variability, so populations numbers would boom and then they would bust, and it was all due to the changes in precipitation and temperature from year to year, and population extinctions had been documented as a response to droughts and other extreme climate events. And remember this was in the early 1990s, so this is when climate scientists were still, they expected the increase in greenhouse gases to be driving warming, but they still weren't sure they were actually seeing a significant warming trend in the globe, and I thought, ha, my little butterfly will be, if anything is going to be an indicator of climate change it's going to be this little butterfly, because it is so sensitive. So I switched to doing this very field intensive climate change project going around from Baja, Mexico, all the way to Canada, from the coast of California, all the way to Colorado, looking at the re-sensicing records of this one butterfly, Uffidri, Zeditha, and seeing whether or not the population was still there, because I thought we know that it goes extinct due to extreme climate events. I was expecting to find a lot of populations extinct, but I was interested in the pattern of that extinction, whether that would tell us anything about climate change. And quite honestly, it was six months of field work a year. I was a grad student, I didn't have any responsibility. It was a lot of fun, very high-risk project. I wasn't sure I'd come out with anything at the end of it, but what happened is at the end of four years of field work, I'm looking at all the data, and it's, of course, you know, about 40% of the populations were extinct, even though the habitat was gorgeous and there's lots of host plant and lots of nectar, and that's what I expected, but I started looking at that pattern, and I thought, wow, the rate of extinction is really high in the south, and it's really low in the north, up in Canada, and you know, it's really low at the highest elevations. I was expecting something very sophisticated having to do with different ecotypes of the butterfly, and I thought, this is seriously simple. It's just shifting its range northward and upward. My goodness, you know, and this has only been with 0.6 degrees centigrade of warming in that region. It couldn't have been simpler. I couldn't have made up the data and had it be a simpler, more clear result. So I got it published in Nature, and boom, as a single author paper, and boom, I was a climate change biologist. You know, overnight, all the evolution, behavior, the other kind of ecology went away, and suddenly, I'm a climate change biologist, and within a year of the publication of that, I was in the IPCC. This was the third assessment of report as a lead author, and I've never turned back. So basically, my heart is still as a field biologist, but while being in IPCC, it was very obvious that we needed some big summary numbers, and that's what got me involved in doing the big global meta-analyses with just any good data set we could find. You know, anything with more than 20 years of data where there was some understanding of the biology of the species, where the system was known not to be highly impacted by humans other than climate change. You know, we had a whole set of criteria, and having done the first meta-analysis, which is the one I did actually with an economist, I just kept doing them because we needed more and more numbers, and people kept giving me their data sets, and so now I'm actually trying to get back to the field work, because I really do miss my butterflies. Well, what surprised me is really the criteria that Gary and I used were based on data quality. So I said, I don't care what the species is. I just need it to be at least 20 years of data, and I need the authors doing the work to know enough about the biology to have an expectation of how it should respond to the climate change that's occurred in that region, and then we need to know that they've considered other things that might be affecting its distribution or its timing. And so really, that took about a year or two years of work just to come up with this set of species that we had good quality data for. And then it was sort of looking at what they were doing, and again what surprised me was I expected big differences between geographic regions and big differences between taxonomic groups, and partly we didn't have a huge amount of data at that time. We do now. We have much more data. But also I said, you know, for every single study, whether it's birds in Europe, or birds in the North America, or butterflies in Europe, or fish in the North Sea, you know, it's like there are always some that are showing really strong responses, you know, shifting pole words by many, many kilometers, or shifting the timing of their breeding to be much earlier. And there's always this group that's showing no response, and then there are always just a few species going the other way. And it doesn't seem to matter whether they're trees, or fish, or birds, or butterflies, or, you know, herbs in the mountains, which really surprised me. You know, I expected all these differences, and what I got was actually no matter what system we went to, no matter where it was in the world, we were getting kind of a very similar picture. And so when we put together the whole meta-analysis, we didn't really have to go into a lot of complicated analyses, because actually the trends were very similar everywhere we looked. And that alone was, to me, a very strong indicator that the anthropogenic climate change was somehow this underlying driver that wasn't necessarily the first thing in the biologist mind working on a particular system. But if you look at that long-term data, you saw that trend driving almost every single system in almost every single region we looked at. So it was a very, very powerful. That consistency of response, even though it was unexpected, was a very powerful indicator that climate change was really driving systems around the world. One thing I've learned talking to a lot of scientists is often the more powerful their research and the more impactful it is in terms of affecting public consciousness, the more it gets criticized by people who don't like that. Have you experienced that with your research? You know what I'm actually quite, and I will say this, I'm quite proud of my research in the sense that the minute I got involved in the climate change world, I knew that climate deniers were going to try to jump on any result that I came up with. So I made a conscious effort to be very conservative and very rigorous. I'm not saying I wasn't rigorous in my science before this, but I made an extra special effort to say is there anything that I can do to design this study to make it sort of airtight. So when I was doing basic evolution of diet, evolution of behaviors, there were half a dozen scientists in the world really keen on that who might really probe into the details of that work, but quite frankly, you know, the rest of the people were willing to accept the result. But as soon as I got into climate change research, I knew that it would be much more heavily scrutinized, and in some senses it was a lot more important to get it right because policy was going to be made based on the results of this research. I had to make sure I wasn't doing anything that could conceivably lead to a result that might be in favor of finding a climate change impact. So I was extra conservative and some people think I was too conservative because if I thought there was anything suspicious about the data set, I threw it out. Whereas other people, it's like, oh, come on, you know, you're being too picky, we should include all the data and just, you know, if there's a signal that will come out. Well, I took the opposite approach. I was actually did a lot of quality control on the studies that I was willing to include, and that paid off. It paid off big time. I remember with the first paper I did showing the northward and upward range movement of Edith's checker spot butterfly, again, I was very careful about how I chose the populations to look at and how I defined the habitat still being suitable. I was very, very rigorous. If it wasn't absolutely, obviously, fantastic habitat, I didn't include the population. And when it came out, I was very proud that Rush Limbaugh talked about it on his talk show, and the only thing he could say about it was, well, you know, this little gal from Texas is looking at climate change, and you know what? He's found this butterfly's moving north. We don't have to worry about climate change. Everything's just going to move a little bit further north. Ain't that wonderful? And I thought, if that's the worst thing he can think of to say about my study, I did it right. And the same thing happened again with doing the meta-analysis with Gary Yeoh. Gary is an economist. Within IPCC, we were having big arguments between the biologists doing observed impacts and the economist because they have very different methodology about how they approach looking for significant changes in economic systems. We were looking for significant changes in biological systems. They felt our approaches weren't appropriate. And fortunately, Gary and I were able to discuss this reasonably, sometimes over a beer, and we were able to realize where those differences were coming from, that it really was a difference in how we were trained, a difference in how we were looking at it. And we were able to reconcile those differences. So with that paper, that first big meta-analysis that I did, we were able to again come up with a study design that was able to deal with a lot of the issues that people outside of biology had with the way biologists were looking at our data. And so again, we came out with a study. We said, look, there are different ways of looking at this. Here's what we've decided on. Here's how we've controlled for publication bias. Here's how we've controlled for cherry picking. And we did such a good job at it that again, it really didn't come under any, it was scrutinized by the climate deniers, but they really couldn't come up with any fault in it. And I was just very proud then of not listening to other people and being super conservative. And the thing is, the changes we're seeing are so massive and so consistent, even taking a very conservative approach and throwing out honestly two thirds of the data, just by trying to get down to that core of really good quality, really unbiased data, even doing that, the signal was so strong. It was so obvious that climate change was impacting natural systems. And so my argument was that even taking the most conservative approach, we have a very, very strong statement, very, very strong conclusions that we can make as biologists about the impacts of climate change. My various papers have had impacts, I think, on really different sectors. Certainly, they've had a big impact on the IPCC because not just because I was a lead author at one point, but even on reports where I wasn't a lead author, my research was cited heavily to come up with statements like what proportion of species are being impacted by climate change, coming up with the confidence levels that we have in those statements. And today we were discussing the Copenhagen Accord came up with an agreement that we should not reach more than two degrees centigrade warming, because to do so would be dangerous. And some of my research is part of that two-degree cutoff level. So it has had an impact in the policy world and in coming up with some of the threshold levels that policymakers have come up with. But almost what I'm as happy about and as proud of is that it has had a huge impact on the applied world of applied conservation biologists, NGOs who are working for being able to preserve biodiversity in the face of climate change. And it's one comment that I've repeatedly gotten is that even though my research is published in the scientific literature, you know, nature, science, global change biology, the major science journals, I've always made a very strong effort to make it readable to people outside of my discipline. And that's been really appreciated because even though someone might have a degree in ecology, if they go off to work for an NGO, it might have been 10 years ago that they got that degree. They're not necessarily up on the current literature. And it's very important for them to have something that they can easily read. So it's for educated people. But as I said, I've had economists read it and actually understand what I'm saying. So I'm very pleased that it takes me a long time to write a paper much longer than many of my colleagues. And if you look at my publication rate, it's much lower than a lot of people at my level. But by colleague, that extra work I put into each of those papers, and it probably takes me three or four times as long to write a paper as many of my peers. But the payoff has been that by doing that I've made things that are very readable to both biologists and applied conservation practitioners and policymakers. So I think that extra effort is worth it. A lot of people are wondering where that two degree threshold limit came from in the Copenhagen Accord. And it doesn't just come from biological impacts on wild species. What was interesting to me is I've been part of testimonies to Congress. So I've been on panels where I've been next to health professionals, people in the insurance industry who work on sort of risk of damages to say coastal cities. And we would not have met each other before being on the panel, right? I mean, that we're in totally different fields. And yet when we were asked, well, what do you think is the threshold for dangerous climate change? Every one of us gave a two degree limit, which is really fascinating that from all these different fields, people were getting kind of converging on that as being, and the key is really what's the dangerous limit? So where does it come from in terms of biological impacts? Well, we've had 0.7 degrees centigrade warming already. And we can already see that we're seeing huge changes in systems. For many systems, the change is not necessarily negative. So if a butterfly moves 200 kilometers north, that isn't necessarily bad for it. It might be going extinct at that southern range edge, but you know, if its whole range shifts north by a little bit, you can't argue that that's a negative change. But even at 0.7 degrees centigrade, we're seeing the most sensitive systems, the polar species, the sea ice dependent species, the mountaintop species are suffering. They're having range contractions, so they're being forced to live in smaller and smaller areas. As those low elevation populations go extinct in the mountains, species are getting more and more restricted to the mountaintops. If the mountaintops are not high enough, they go extinct. And we've been seeing this already with 0.7 degrees centigrade. So in looking at the changes through the temperate regions of sort of Europe and the USA, as well as going into the boreal regions of Canada and Sweden and Finland, I was able to come up with a conclusion that from the observed changes with two degrees warming, so three times as much as we've already had, we will very likely lose the most sensitive systems, the most sensitive species, because we're already starting to. But it looks like a lot of the species in the middle attitudes will have big changes, but won't necessarily go extinct. And so when you talk about dangerous climate change, what I tried to emphasize is it doesn't mean we're not going to have species go extinct. It means that the predominance of the biomes on earth will change, but we'll probably be able to adapt at least with some human help, we'll be able to survive that degree of warming. So it's not that we're saying two degrees is fine, you know, it's okay, because I don't really like the thought of losing the polar bear, but I think we are going to lose the polar bear. I mean, it's already happening, the changes are already very big. We're already losing some of the very high elevation mountaintop species. I can't see them surviving through three times as much warming as we've already had. But if you ask me how big overall is that an impact on global species richness, global biodiversity, global ecosystem functioning, I would say, well, most systems are going to be more or less okay. So that's where the two-degree centering comes from. And it's the same if you're talking about human health impacts. We're already seeing health impacts of climate change. We are already seeing that the heat waves of 2003, this recent heat wave that we've had in 2015, those have both been linked to greenhouse gas driven climate change. They've killed a lot of people. So if we're already getting heat related deaths due to anthropogenic climate change, obviously two degrees is too much if you're saying we want no impact. But that wasn't the way it's been worded. It's been worded as what's the dangerous level. So in other words, at what level would human health reach an epidemic? At what level would the hospitals be overwhelmed? At what level would the medical system be overwhelmed? And that's where you get to that two-degree. It's not saying there's no effect until you hit two degrees. It's saying we think most health systems can manage until you get to two degrees, and then you really get to a tipping point where a lot of health systems cannot manage. I think what people don't understand about the two degrees, they think we're saying it's okay up to two degrees. The trouble is that's not what the policymakers are asking. They're really asking about tipping points. When do we start crossing the tipping point and having collapse of our economic structure, having collapse of coastal cities, having collapse of our medical system being able to deal with either tropical diseases or heat-related deaths or whatever the issue is. And it's the same with biodiversity. They're asking us what's the tipping point at which you start seeing sort of losses of some of the major ecosystems that we rely on. And so that two-degree limit is the two-degree limit for dangerous climate change. And unfortunately, that word dangerous is a bit ambiguous, but it's very clear that the policymakers are not calling one species going extinct. The polar bearing going extinct isn't dangerous climate change. They're really talking about a much more major tipping point of a whole system, a whole suite of species. In my own work, I do a lot of public outreach. I do a lot of talking to school-age students. I do a lot of talking to educators who educate school-age students. And it always has been a question of how do you get them to understand both the complexity of climate change and also the urgency. Because you have to explain it very simply, and yet it really isn't all that simple. And so what I've done, and a lot of this started in working in Texas where there's a very strong climate denial movement, and I'd be giving public outreach talks to groups of, say, petroleum geologists who were going in absolutely convinced that they were going to hate my talk and they were going to skewer me at the end of it. And what I'd find is I do something that actually communicators tell you not to do. I show data. I show graphs. I show little dots, you know, of data on the map. And I found that that's actually very powerful. If you've got a skeptical audience, you need to show them the data because chances are they've never seen the data. And I have had people who admit to me that they were die-hard climate deniers, absolutely didn't believe climate change was happening. And even if I could convince them it was happening by golly, it wasn't humans. They'd listen to me give a lecture for an hour, and they would, to their credit, they would come up and they'd say, little lady, you know, I was prepared to not believe you. And I was actually prepared to really come down on you hard in the question period. But, you know, you've given me a lot to think about. And I've never seen that data. Where is that data? And I say, look, don't believe me. You look it up yourself. And I give them a list of scientific and credible websites and say, look, if you don't like that, at least let me tell you how to sift through good data from bad data. And they would go away puzzled because they thought they knew what they were talking about and they found out they really didn't. That's been very powerful. In talking to younger groups, like school-aged children, the funny thing is I found that pretty much the same approach works. You have to be a little simpler with the data. You have to be a little more careful not to show them anything that's going to be beyond the jargon that they know. But actually, they're pretty sharp. I mean, kids, I've gotten better questions from 10-year-old kids than from adults because in a sense they don't have the preconceptions. They don't have a political bias yet. They're 10 years old. And so if you can just explain it clearly enough that they understand the logic and they can understand, you know, they can see a trend line. They can see something going up. And, you know, I'll get a kid saying to me, well, but, you know, if species are doing moving north now and if the polar bear is already at the top, isn't it going to go extinct? It's like, I didn't say that. That's what they came up with. And it's like, yeah, actually, you're probably right. And it's so funny as their parents get more upset than they do. And, you know, the 10-year-olds can handle it. They can handle catastrophe. It's the parents who just, you can't tell my child the polar bear is going to go extinct. And I say, well, I can't lie to them either, can I? That happens to me more often than you would think. So I actually do. I'll go to a party or I'll go to a dinner where I'm just wanting to be social, right? And people will say, well, what does do you do? Well, I'm a professor. What do you professor of? Biologist. And I tend to like keep it at that. And my husband will jump in and say, oh, she works on the impacts of climate change. And then suddenly, the whole conversation is climate change. I just don't know if I believe that. That's usually the common. I just don't think I believe that. And so I've got my little pattern down, which actually comes from teaching in courses. And I say, look, you don't have to, it's not a belief system. It's a reality for one thing. So your belief doesn't actually enter into this at all. And what you're saying is you don't understand the information that's going into the conclusion that this is really happening. So we've got about three major lines of evidence. You've got the basic physics that greenhouse gases are insulators. We know this. You put a candle here, you put a greenhouse gas here, you put a thermometer there, and by golly, if it's a greenhouse gas, that temperature doesn't go through. If you put in something, it's not a greenhouse gas. The thermometer records the heat. We've known this since the late 1700s, by the way, when these experiments were first done. Second thing, we have patterns of climate change that are indicative of the warming being induced by an insulation effect rather than an increase in solar energy. And they always say, well, what do you mean patterns of warming? I say, well, would you get more warming by night or day if the warming were by insulation? And they think for a minute. And I say, well, what happens on a cloudy night versus a clear night? Cloudy night, you don't get a temperature drop. Clear night, you do, right? Water vapor is an insulator. Water vapor is preventing the heat from leaving. So if you're looking at the long-term data trends, what you see is for the last 30 years, the warming has been mostly by night and not by day. So what does this tell you? I try to get them to sort of think through. It's like, oh yeah, that means it's insulation. It's not increased solar activity, right? And I say, same thing with winter versus summer, right? If the warming is due to increased insulation, is winter going to be warming more or is summer going to be warming more? They think for a minute. I say, well, there's this warming period in the 1930s, 40s. That's considered to be natural. And in that warming period, it's summer warmed more than winter, days warmed more than nights. Past 30 years, it's been the opposite. Winters warmed more than summer and nights have warmed more than days. 1930s, 40s, it was due to increased solar radiation hitting the earth. Now it's due to increased insulation. And then I finally say, and there are these climate models, but I always leave that for the last because people don't trust models who are unfamiliar with how that process works. So I always leave that for the last and say, and you can construct these sort of mathematical experiments where you put in all the known information about the physics of the greenhouse gases and how much solar radiation is hitting the earth and volcanoes, and you put all that together. And what you find is the models tell us that the warming of the 30s and 40s was principally due to increased solar activity, and the warming now is principally due to greenhouse gases. So you have all these different lines of evidence pointing to the same thing. It took a little more than, I don't know how long that just took, but I can do it more succinctly if I've had a few cups of coffee. But it usually works. They usually go away saying, you know, same thing as the petroleum geologist at the end of my lecture. It's like, huh, wow, I've never heard any of that. And it's like, well, it is out there. It is in the newspapers. It's just that people have a bias about what they choose to read. And so they think they have all the information. When you make it clear they don't have all the information. And in fact, they have almost no information. It makes them at least, I'm not saying I convince people instantly, but I convince them enough that they need to go check it out much more deeply. And that's, I think, as best you can do with someone who's starting out as an obvious skeptic. Changing the world while I'm texting the dinner party at a time. I actually, funnily enough, have met climate deniers in giving public outreach lectures in the UK, which really surprised me. I wasn't expecting it. Texas, I expected. But every UK talk I've given, I've had one person who's a climate denier. So what impacts have you, I guess, as your research had? I guess who? Who reads it?