Camille Parmesan Part 2: Seeing a healthy ecosystem, alive and vibrant, helps me to be a happier person

This is Part 2 of my conversation with evolutionary and behavioural biologist Professor Camille Parmesan, of Plymouth University and the SETE/CNRS Ecology Centre in Moulis, France, in which Camille talks about the moments when she realised how severely climate change was already hitting a wide range of plants and animals, two decades ago.

PU: If you had to tell the story of where you are, and how you feel about dealing with climate change, can you identify any personal realisations, or transformative moments in this path that you’ve been on? Where the lights suddenly came on about something?

CP: Several. The first one was when I received a grant from NASA’s ‘Mission to Planet Earth’ programme. I had been working on my PhD with a really climate-sensitive butterfly, Edith’s checkerspot. At the time I was doing this work, climate scientists had not yet nailed down a significant warming trend. I knew from first principles, basic physics, that greenhouse gases are going to cause warming. But the timeline for impacts was unknown – was this a few hundred years down the road? Really, no one knew, at that point.

So I thought, maybe this climate-sensitive butterfly would be a good indicator species. And what I found really freaked me out. After four and a half years of fieldwork, I realised that this butterfly was just massively moving northward, a huge change across the species range. I was expecting something really subtle, very complicated, requiring sophisticated analyses with climate data for each population.

I went home to my husband, and I said, Michael, you know what I think has happened, I think we’ve just had a range shift. And I thought, well, holy shit! Not only was it real, which I sort-of intellectually knew, anyway, but it was already having this massive impact. And the scientists weren’t even seeing a clear warming trend yet. And it freaked me out, I mean seriously. I knew then, this is going to be much bigger than anyone thinks.

PU: When was this?

CP: I first thought this was happening in 1994, after three years of fieldwork, and I decided I needed to nail it down. I went back to Mexico in 1995, where there had been southern extinctions, to get the sample size up, so that I could be positive it was really happening. So I doubled the sample size, nailed down that the extinctions were really high down there, and published the paper in 1996. It was really that second field trip in Mexico, where it was, ‘oh my God, extinct, extinct, extinct’.

PU: So 23 years ago, and it was crystal-clear?

CP: Yes. It was, like, this is not subtle. And the next time I had one of those moments of realisation, I was doing the very first meta-analysis, which was motivated by the IPCC, to provide information for policy makers. I kept being asked, what percentage of species are being impacted? We know about your butterfly, but it’s really sensitive, and it’s just one butterfly. And we didn’t have the numbers together, and that motivated me.

So I worked with Gary Yohe, an economist, which helped me see how other people were thinking about it. We sorted through the papers and put together the numbers. Gary asked me, ‘Of the things that are changing, what percent are in the direction you’d expect?’ and I said, ‘Oh I think it is somewhere between 85 or 90%’, and it was actually more like 95%. But the key issue was the proportion of species that were changing, and I said ‘Well I don’t know that, because we have to look at all the non-changers’.

So we had to figure out how to do it, and slog through extracting the data from papers. And it was only when I was slogging through all the papers, and only looking at multi-species studies, so that you had non-responders as well as responders. We had to throw out tons of studies that were too biased.

Then we got down to this core, where you found that 50% of species had changed their range, two-thirds of species had changed their phenology. It was that same like, ‘Oh my God, you have got to be kidding me. It’s not just a few sensitive species.’ And in every taxonomic group, every system, marine, freshwater, terrestrial, it didn’t matter.

There was no geographic area that was immune, no taxonomic group, and that really hit me. Because I knew what was happening with butterflies, but okay, butterflies are sensitive, so I thought, well maybe Pacific fish are no problem, maybe the Pacific Ocean is fine. But then, slogging through the papers, I found no, it was not fine. The Atlantic Ocean, not fine. Tropics, not fine. You know, you think maybe heat-adapted systems would be okay – but no, they’re even more sensitive. (She sighs – a big sigh).

So that was the second moment of realisation, and that was 2003, when that got published. And by 2009, why I was so depressed before COP 15 in Copenhagen, was because there were massively shocking results, and policy makers weren’t doing anything. (laughs incredulously) It’s like, how can you get stronger evidence?

And it wasn’t just in the natural systems, you were getting the same kind of evidence in economic analyses, hurricane analyses, so all of them were supporting each other. Every discipline was getting its own shock. And I’d meet the people in other disciplines, like Kerry Emmanuel, who did the hurricane analysis, it was the same thing, it was like, ‘Oh my God, they are really getting significantly stronger, right?’ And so, you know, then meeting these people in other disciplines and thinking okay its not just (laughs) biodiversity, it’s everything, and we are not seeing any action.

So that’s why by 2009, I was asking myself, why am I doing this? I thought, I am just going to go back to the mountains, the places I know are doing well, do my basic research, and forget about this, because no-one’s paying any attention. And then in Copenhagen I met all these energetic young people, and that was another turning point. I felt, okay, maybe it is worth staying in this and keeping on plugging away and helping to get the evidence. So that was fairly short lived. (We laugh)

PU: I’m interested in what people use as sources of comfort, when dealing with the immensity of climate change. Is there something like that for you – music, a piece of art, nature?

CP: Going back to work with my butterflies in California that are doing fine. (Laughs). Going up into the mountains, because the mountain ones are doing fine. We were there for two weeks, we just came back, and that makes you feel, ‘yes’. I love it, I love going into the field and having hundreds of butterflies flying around, they’re healthy, they’re happy. It’s like, thank you, I need to see this. And not going to another dead coral reef.

PU: So the source is nature, it’s these specific instances you’ve described?

CP: Yes, that really makes me feel that something is okay, something’s doing all right, and I can be glad. And I mean I love music and I love dancing, I do all those things, but if you talk about what really makes me fundamentally feel better, it’s that: going out and seeing a fundamentally healthy system. Seeing everything being alive and vibrant. Which is why I’m moving to the south of France. It’s going to be so much fun, because it’s still beautiful down there. And fabulous biodiversity, fabulous floral biodiversity, butterflies, birds, …

PU: Which is the butterfly that is doing well in the mountains?

CP: Edith’s checkerspot – it’s the same species going extinct in Mexico, going extinct at a very high rate at low elevations. I don’t go to those sites anymore … (laughs). But it lives from sea level up to 3,400 metres; it goes up as high as the vegetation goes. The high elevation populations are doing great, in the Sierra Nevada, in California. It would be true up in Canada as well, but I didn’t have time to go there. So through the Cascades, the Rocky Mountains, the Sierra Nevada, all of those populations above about 2,400 metres are doing really well. And they’re even doing well in the national forests where they’re not protected, so it’s great, it means they’re not quite so sensitive, they can handle a bit of disturbance.

PU: Why do you think that is – because it’s cooler at higher elevations?

CP: These butterflies are not mountaintop restricted. Mountaintop-restricted species are not doing well. But because these actually live from sea level to the mountaintops, they weren’t limited at the higher elevations. They like a hotter summer; hotter is actually good for them. As long as they get good snow pack. And the mid-elevations are not getting good enough snow packs, so they’re coming out too early, they’re getting false springs, so they’re getting very screwed up. But at the very highest elevations, where snow pack if anything is increasing, because the warmer climate causes more precipitation, as long as you’re above that snow line, they’re doing great. They love a heavy snow pack, they don’t come out until July, then it’s nice and hot, boom! They bomb on, then they’re asleep again when the winter snows start. So we know why they’re doing well.

But with the mountain-top restricted species of course, their lower elevation populations are only a third of the way down the mountain, like the pika (a small mammal), the American pika and the Nepal pika, are not doing well. Some of the mountain top butterflies, like the Apollo butterfly, those are doing horribly because the lower elevation populations are going extinct, and they only were at the top quarter or fifth of the mountain anyway. So, if you think about the area relationship, they’ve lost a huge amount of geographical area, being restricted now to this tiny peak.

But fortunately that’s not the situation Edith’s checkerspot is in.

PU: Does that help you to respond practically?

CP: No, I don’t think I see a connection with that. No, it just helps me be a happier person.

PU: So it isn’t that it might help you to continue to work in the field?

CP: No, because you know I am actually trying to get back to doing some basic research with the butterflies, looking at the thermal ecology. But I’m still doing research that’s more in line with what the policy makers are interested in, like getting into human disease, and how changes in the ranges of vectors in reservoirs will affect disease risk in humans, and that kind of thing.

Which again is not fundamentally what gives me the most personal pleasure. But it’s important and there’s satisfaction in getting those numbers as well, even though again it is kind-of depressing, putting it together. So, no, I think I’m starting to have two sides of my professional life, the side that I think is the most important for policy makers to know, and the research side that gives me the most pleasure.