She is an ecologist recognized worldwide for being the first to unequivocally demonstrate the impact of climate change on a wild species: the Edith’s checkerspot butterfly. In recent years, however, Camille Parmesan has been interviewed not only for her expertise on the future of biodiversity in a warming world or for her share in the Nobel Prize awarded to the IPCC, but for her status as a refugee scientist.

Twice in her life, she has chosen to move to another country in order to continue working under political conditions that support research on climate change. She left Trump’s America in 2016, and later post-Brexit Britain. She now lives in Moulis in the Ariège region of southwestern France, where she heads the CNRS’s Theoretical and Experimental Ecology Station.

Speaking with her offers deeper insight into how to protect biodiversity – whose responses to climate change continue to surprise scientists – what to do about species that are increasingly hybridizing, and how to pursue research on a planet that is becoming ever more climate-skeptical.

The Conversation: Your early work on the habitats of the Edith’s checkerspot butterfly quickly brought you international recognition. In practical terms, how did you demonstrate that a butterfly can be affected by climate change? What tools did you use?

Camille Parmesan: A pickup truck, a tent, and a butterfly net, good strong reading glasses to search for very tiny eggs and caterpillar damage to leaves, a notebook and a pencil to write notes in! In the field, you don’t need more than that. But before doing my fieldwork, I had spent a year going around museums all across the USA, a couple in Canada, and even in London and Paris collecting all the records for Edith’s checkerspot. I was looking for really precise location information like ‘it was at this spot, one mile down Parsons Road, on June the 19th, 1952’, because this species lives in tiny populations and is sedentary. That process alone took about a year, since at the time there were no digitized records and I had to look at pinned specimens and write their collecting information down by hand.

Once in the field, my work consisted of visiting each of these sites during the butterfly’s flight season. Since the season lasts only about a month, you have to estimate when they will be flying in each location in order to run a proper census. For this, you start by looking for adults. If you do not see adults, you do not stop there. You look for eggs, evidence of web, like bits of silks, damage from the overwintering larvae starting to feed…

You also look at the habitat: does it have a good quantity of healthy host plants? A good quantity of healthy nectar plants for adult food? If the habitat was not good, that location did not go into my study. Because I wanted to isolate the impact of climate change, from other factors like habitat degradation, pollution… At the larger sites, I often searched more than 900 plants before I felt like I had censused enough.

Today, when you go back to the fields you started monitoring decades ago, do you see things you were not able to see at the beginning of your work?

C. P.: I know to look for things I didn’t really look for when I started 40 years ago, or that my husband Michael [the biologist Michael Singer] didn’t look for when he started 50 years ago. For instance, we discovered that the height at which the eggs are laid is a bit higher now, and that turns out to be a really significant adaptation to climate change.

The eggs are being laid higher because the ground is getting far too hot. Last summer, we measured temperatures of 78°C (172.4°F) on the ground. So if a caterpillar falls, it dies. You can also see butterflies landing and immediately flying up, as it is way too hot for their feet and they’ll then fly onto vegetation or land on you.

In my early days, it wouldn’t have occurred to me that the height of where the eggs are laid could be important. That is why it is so important for biologists to simply watch their study organism, their habitat, to really pay attention. I see a lot of young biologists today who want to run in, grab a bunch of whatever their organism is, take it back to the lab, grind it up and do genetics or look at it in the lab. That’s fine, but if you don’t spend time watching your organism and its habitat, you can’t relate all your lab results back to what is actually happening in the wild.

Thanks to your work and that of your colleagues, we now know that living organisms are greatly affected by climate change and that many species must shift their range in order to survive. But we also know that it can be difficult to predict where they will be able to persist in the future. So what can be done to protect them? Where should we be protecting lands for them?

C. P.: That is the big question plaguing conservation biologists. If you go to the conservation biology meetings, a lot of people are getting depression because they don’t know what to do. We actually need to change the way we think of conservation, away from strict protection toward something more like a good insurance portfolio. We don’t know the future, therefore we need to develop a very flexible plan, one that we can adjust as we observe what’s happening on the ground. In other words, don’t lock yourself into one plan, Start instead with an array of approaches, because you don’t know which one will work.

We just published a paper on adapting, for land conservation, some decision-making approaches that have been around since the 1960s in fields known to be unpredictable, like economics, for instance, or urban water policy, where you don’t know in advance if it is going to be a wet year or a dry year. So urban planners came up with these approaches for dealing with uncertainty.

With modern computers, you can........

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