Science Friday - The Global Mental Health Toll Of Climate Change | Capturing DNA From 800 Lakes In One Day

Episode Date: April 22, 2024

An explosion of research is painting a clearer picture of how climate change is affecting mental health across the globe. Also, a citizen science project aims to find species that have gone unnoticed by sampling the waters of hundreds of lakes worldwide for environmental DNA.Assessing The Global Mental Health Toll Of Climate ChangeAs the effects of climate change become more visible and widespread, people around the globe are dealing with the mental health impacts. But what are those impacts exactly, and how do they differ between people in different parts of the world? That’s been the focus of a rapidly growing area of research, which is seeking to understand the psychological impacts of climate change, sometimes referred to as “eco-anxiety.”Guest host Maggie Koerth is joined by Dr. Alison Hwong, a psychiatry fellow at University of California San Francisco, to talk about what scientists have learned about global eco-anxiety and what strategies they’ve found to reduce its more harmful effects.Citizen Scientists Will Capture DNA From 800 Lakes In One DayTaking an accurate census of the organisms in an ecosystem is a challenging task—an observer’s eyes and ears can’t be everywhere. But a new project aims to harness the growing field of environmental DNA (eDNA) to detect species that might escape even the most intrepid ecologists. In the project, volunteers plan to take samples from some 800 lakes around the world on or around May 22, the International Day for Biological Diversity. Those samples will then be sent back to a lab in Zurich, Switzerland, where they’ll be analyzed for the tiny traces of DNA that organisms leave behind in the environment.Dr. Kristy Deiner, organizer of the effort, hopes that just as lakes collect water from many streams across an area, they’ll also collect those eDNA traces—allowing researchers to paint a picture of the species living across a large area. She talks with SciFri’s John Dankosky about the project, and how this type of citizen science can aid the research community.Transcripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Bio-researchers trying to sample water from hundreds of lakes around the world. If this works, what it does is it gives us a very effective way to sample biodiversity for the least amount of effort. It's Monday, April 22nd. Happy Earth Day. It's also Science Friday Day. I'm SciFri producer Charles Bergquist. Coming up, we'll hear about a project to try to take a census of biodiversity using the environmental DNA left behind in lakes. But first, guest host Maggie Kerth takes on the topic of eco-anxiety, the fear and depression caused by impending climate change, and how new research is helping scientists better understand how it manifests in different parts of the world. In the last few years, the fear and depression caused by climate change has gone from something we doomskroll about to something scientists are now seriously studying. They're finding that eco-anxiety is something we humans all share. all around the world. But it looks different and has different impacts depending on where you are

and who you are, kind of like climate change itself. Here to tell us what scientists have learned about the mental health impacts of climate change is Dr. Allison Huang, clinical instructor at the University of California, San Francisco. Welcome to Science Friday. Thanks. I'm happy to be here. Thank you for joining us. I want to start out by defining what we mean by eco-anxiety. When this term comes up in science, is it referring to fear and dread of immediate risks? Is it referring to existential doom about the future? Is it referring to that feeling of powerlessness to change something so much bigger than your own choices? And please stop me if I'm just using you as my personal psychiatrist now. So those are good questions. So yeah, this term eco-anxiety, there are other similar terms,

climate distress, climate grief or climate anxiety. There's also a term solostalgia, which refers to kind of a nostalgia for your environment, even though you're still living in it, for kind of what used to be your environment and is disappearing or fading away. These are all terms to describe this kind of phenomenon we're seeing of the experience of loss, increasing loss of an inhabitable planet. And I think it encapsulates many of the things you just said. You know, it incorporates anger, frustration, and grief around choices that have been made and seeing that many of the people in power maybe haven't made choices so that our planet could continue to thrive.

It includes, you know, just sadness about the loss of islands and different landscapes that we find beloved. And so I think that, yeah, all of that could have incorporated in, in those terms. When you're looking at your patients and at data, how do you see those impacts playing out in their lives? Yeah. So just stepping back, we do generally think about climate change related mental health effects on three levels, one being these direct impacts. So if you've experienced a hurricane or flooding, wildfires that have destroyed your home, you might experience that's a traumatic event. So we might see depression, anxiety.

post-traumatic stress disorder out of those events. And then we also think about indirect effects of climate change. So if drought has affected your crop yields and you're a farmer, that that might affect your economic livelihood. And then that could also affect depression, anxiety, mood symptoms. And then we think about things like eco-anxiety, which is this more holistic meta-experience of seeing climate change happen and seeing the planet change.

So I think all three of those kind of come to the clinic. And I see mostly older patients now, but I do see some young adults. And there definitely are differences in, like, young adults are experiencing, you know, more of the acute effects of climate change. And part of it is, you know, for young people, they will live their entire lives affected very much by this rapid climate change, you know, from the day they're born. And older people tend to have often built more of resilience over their lifetimes. So I see things both, you know, in my area and Northern California, people are affected by the wildfire smoke when they can't go out of their house safely.

It's very existential not to be able to safely breathe the air outside of your home. There was this large international survey that was done in 2021. And I'm really curious to find out a little bit about how eco-anxiety looks different and how, how it looks similar all around the world. Yeah, this was a great study. This was done by Carolyn Hickman and her colleagues in the UK and the U.S. And they surveyed about 10,000 young people, ages 16 to 25, across 10 diverse countries around the world. And they asked, how worried are you about climate change and how much does climate change affect your daily functioning? And at least to my surprise, the U.S. and the U.K. came out near the bottom of the list in terms of how worried young people were about climate change. And the countries where respondents had the most worry were the Philippines, Brazil, Nigeria, India. And so this idea that worries about climate change is a wealthy country problem or wealthy people are worried about it. I think that was very much overturned through that survey.

Are there differences in how these mental health impacts play out for people depending on place, depending on cultural response? Do you see something different for how people are suffering from eco-anxiety in Brazil versus those in India, for example? That's a really good question. I will say that there have been studies looking at various indigenous communities who have, of course, long cultural ties to the land and whose very livelihoods bound up with working on the land, tending to the land. And those are groups that seem to be disproportionately affected by climate change. Also groups where sometimes these are island nations, where the very islands they live on are disappearing. So these are groups where more research has been done in terms of the type of grief, where you're really losing your ancestral home,

which is, I think, a very different level of loss than for others of us who have moved around a lot. So the story of what's driving eco-anxiety, the effects it has on people, those can all vary from place to place, how does that change how scientists talk about solutions? Are there different ways to lessen eco-anxiety if you're in the U.S. versus if you're someone in the Philippines? Yeah, good questions. Well, no, some of the work being done is actually about empowering local communities to develop their own solutions. In terms of some of the kind of recommendations for managing eco-anxiety, we often say, you know, this, we didn't get here alone through just individual action and we won't get out of this alone. So really connecting to your local community

and taking collective action is one really productive way forward. Finding some way to feel like you have agency in this and you can take a step forward. And so finding local groups, There are these groups called climate cafes, which are groups that gather and talk about distress related to climate change and potentially ways to move forward. Those are ways that I think we can kind of locally think about what is my sphere of influence and how can I actually, you know, meaningfully move forward and make sense of what's happening with climate change in my area. If you don't mind talking about this a little from a personal perspective, I am really curious about how it feels to study. something that is so powerful and so painful. In doing this work, do you feel like you're taking on more eco-anxiety or that you're taking action in ways that alleviates it? Yeah, that's a good question, too. There are two sides of the coin. One is there is a kind of secondary trauma. I mean,

I do approach this from a trauma-informed perspective. So any of us who see people who experience trauma. There is a secondary type of trauma from bearing witness to all of the trauma and loss and trying to heal the healer. On the other hand, I do think doing this research is my way of taking action and feeling I have some agency so that I don't just feel like I'm helplessly watching climate change happen in front of me. So to me, it's a productive and meaningful way to move forward. Thank you so much for taking the time to talk with us about this. Thanks. Dr. Allison Wong is a clinical instructor at the University of California, San Francisco. Taking an accurate census of all the life in an ecosystem is a pretty challenging task.

And observers' eyes and ears can't be everywhere. But what if researchers could use nature itself to collect their samples? There's a new project that aims to explore ecosystems via the environmental DNA, or E-DNA left behind in lakes. Dr. Christy Diner is an assistant professor at the Department of Environmental System Science at ETH Zurich in Switzerland, and she's coordinating this effort. Welcome to Science Friday, Dr. Diner.

Thanks so much. I'm glad to be here. So tell us about this project. What exactly are you trying to do here? We are trying to understand if lakes are acting like a biodiversity sensor in the landscape. DNA is coming off of every species. where they live. And what's special about water is that it's flowing. And so once water comes from the landscape and ends up in a lake, what we're testing is whether or not the DNA is sort of

getting into this big lake and whether we can sample that. And it tells us all the species that are living in that landscape as well as what's living in the lake. If this works, what it does is it gives us a very effective way to sample biodiversity for the least amount of effort, meaning that what we've calculated is there's about 1.4 million lakes on the surface of Earth, and if we calculate that land around the lake that's connected to the lake in its lake watershed, this is about 25% of the surface of Earth. And that would give us a really fast way to sample a huge, huge amount of diverse biodiversity. Interesting. So why don't we back up for a second? And when we talk about

environmental DNA, what exactly do we mean? I mean, where is this DNA coming from? Yeah. So that's actually just being shed all the time from an organism. It can come from just interacting with the surface. We know this when we touch a surface ourselves. We use this in criminal investigations, right? They also are moving around in the environment and leading, you know, maybe hair or pooping, and they can transport what they're eating through that. So we also get signals of the movement of DNA because species are moving around and they move around other species in their stomach with them. So you've got almost like a soup of these DNA samples in this lake. So how do you sort out who's who in there and what what you've actually got in this big old lake soup? Yeah, right?

So over the last, let's say, 50 or so years, scientists have been sequencing DNA from different species. And in that process, we've actually created databases where we know that that DNA came from a specific individual. And because we have that database, we know what unique sequences belong to certain species. Now, when we go to the lake soup, we find our. these DNA sequences, but we have to sort them out. And so we do basically a matching game, like a puzzle. You know, does this DNA match with this DNA sequence that's in our database? And if it does, at the right amount of similarity, then we can assume that it's from that species, and we can assign its taxonomic name. So how long does DNA stick around? I mean, you used the

example earlier of people testing for DNA crime scenes, right? And a lot of it has to do with how long that sample DNA might be able to exist in that environment. So is it possible that you're actually going to be sampling DNA that was introduced into this lake environment years and years ago, and the animal that left it behind doesn't even live around here anymore? That's a great question. The answer is, in water, we've done quite a lot of research to understand that DNA degrades relatively fast. This was a question we had at the beginning of this. of the work. And what we know from all those scientific studies now is that the DNA degrades within most of it within a few hours, but it can have a really long tail, and that can go out to

almost a month. And because our measurement tools are so sensitive, we can actually detect that DNA that's been around for even a month. And when we did the modeling of how fast water actually runs off the landscape. I had no idea about this because I'm not a hydrologist, but I've worked with some now. And what we found is that water moves really fast. And for all those global lakes that we've looked at, that 1.4 million, we see that it only takes a few hours to a maximum of like five days to go from the farthest point in a river to get to that lake. So we predict that any lake should actually be working this way because the decay of DNA is not that fast. That's really interesting. So I understand you've got a big day in this project coming up in

May. Tell us what happens then. Yeah. So when we thought about this project, we thought, what would be something that we could align this with that would be of interest to gauge whether or not we could get the attention of just ordinary people who'd want to participate in the project. And so we picked International Day of Biodiversity, which is May 22nd. Prior to that day, everyone who signed up for the project is receiving a little kit. And inside that kit, it's about a three-liter bucket. And inside that kit, there's a little hand pump and a filter cartridge, and a little hose and a little tube that they're going to put the sample in after they filter water. So they get this kit and they bring it with them and they go out to the lake.

And the idea is that they sample close to where the rivers are coming in, but still in the lake. And they go around the lake to hopefully five to ten locations. And then at each location, they're going to take that bucket. You know, sample about that three liters or maybe a little bit less. And then they're going to use this hand pump with the filter cartridge attached to it. and they're going to filter the water through that. And then they go to the next site and the next site and the next site and at the end of the day, they will have hopefully sampled around 30 liters of water from that lake.

And then they have to transfer this little filter into a tube and that preserves it. And that can be stable at room temperature for like six months. And what we're doing is having everyone send back their samples to ETH and Zurich. and we're passing them there in our EDNA laboratory. How many of these buckets are you sending out? I mean, how many volunteers are taking part? Yes, and we have a goal of about 800th that will go out to a little over, I think, 500 different partners all over the world, spread across 80 different countries.

That's fantastic. I'm sure that a lot of people who are listening right now are saying, I want to sign up. Can I still be a volunteer or have you closed this out now? Yeah, we have closed it out now, unfortunately. But if we're really successful, the end game here is actually that we can turn this into a biodiversity monitoring system. So if we show this works really well, then it may be something that we can implement locally and then we can maybe use this International Day of biodiversity in the future as a means for us to all get out and generate the data that we need to understand what's happening to our ecosystems. It really is an exciting project. I want to thank you for sharing it with us today. Dr. Christy Diner is an assistant professor at the Department of Environmental System Science at ETH Zurich in Switzerland.

Thanks so much, Dr. Diner. I appreciate it. Thank you. That's it for today. Tomorrow we'll hear about a landfill containing tons of radioactive waste near St. Louis. And what happens when your Superfund site lies in a floodplain? Thanks for listening. I'm SciFri producer Charles Berkwist. We'll see you soon.