Climate and Health with Dr. Danielle Buttke

Headwaters

A conversation with Dr. Danielle Buttke, who works for the National Park Service at the intersection of human, wildlife, and environmental health. This episode was recorded in September 2023.

Glacier Conservancy: https://glacier.org/headwaters Frank Waln music: https://www.instagram.com/frankwaln/ Stella Nall art: https://www.instagram.com/stella.nall/

Climate change in Glacier: https://www.nps.gov/glac/learn/nature/climate-change.htm Public health in National Parks: https://www.nps.gov/orgs/1735/index.ht

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TRANSCRIPT:

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Lacy Kowalski: Headwaters is brought to you by the Glacier National Park Conservancy.

Peri Sasnett: This is Headwaters, a podcast made in the verdant wonderland that is Glacier National Park. Millions of people come here each year looking for a break from the stresses of everyday life. My name is Peri, and this episode is an interview that my co-host Daniel did with Dr. Danielle Buttke, talking about the intersection of climate change and public health. They talk about how the health of our climate, environment, and communities is all intertwined. This episode is part of a series of conversations we've been having with a wide variety of climate change experts. These episodes don't have to be listened to in any order, each one stands on its own. And they all focus on a particular aspect of the way the world is being altered by the burning of fossil fuels. Over the past century and a half, human activity has released enough greenhouse gases to warm the Earth's climate over one degree Celsius, with only more warming on the way. Throughout 2023, Daniel sat down with experts to talk about how that warming is altering Glacier National Park, our lives and our futures.

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Peri: I've always been interested in the idea that people and nature are deeply connected. Maybe you know that already, if you listened to our season on whitebark pine. Still, I don't think I was prepared to hear Dr. Buttke explain these interconnections with so much scientific rigor. I was also struck by how profoundly our health is connected to our climate. I think this interview is essential listening.

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Daniel Lombardi: So thanks for talking to us. We wanted to talk to you, Dr. Buttke, about public health and climate change and how climate change is impacting human health and the health of our natural environment, and how those two things are intertwined and all tangled up together.

Danielle Buttke: I'm excited to be here today.

Daniel: So you have an impressive background, right? You have a Master's in public health. You've studied environmental sciences, and you also have a degree in veterinary medicine, the health and epidemiology of animals. Is that kind of a good summary of that?

Danielle: It is, yeah. I had a little bit of a circuitous route to where I am today. Originally wanted to study and work in environmental science and wildlife conservation, which was where my, my Ph.D. work really focused, and realized somewhat early on that animals knew how to survive just fine. It was really that humans were, were taking over the resources and had basic needs that, that needed to be met before we could ask them to conserve resources for tomorrow. And that's when I switched to public health.

Daniel: So what's your job now? Tell us about where you work and what you do.

Danielle: So I currently lead the One Health program for the National Park Service, and One Health is simply the recognition that both human health, animal health and environmental health are all completely interdependent and interlinked. And when we think about the multiplicity of health outcomes and players, when we're looking at a specific problem, we all benefit when we think about health as a more holistic construct.

Daniel: A lot of times I think your job gets really kicked into high gear when like there's a hantavirus outbreak or something in a national park. Is that right?

Danielle: It is, yeah. Because we share so much of the same biology with other species, we often share a lot of the same diseases. Diseases that pass between humans and animals -- and they can often go in either direction -- SARS-CoV-2 or COVID is a perfect example of that, you know, they're called zoonotic diseases. And that's really where I got my start and where a lot of my work is focused, on those infectious diseases that can pass between humans and animals. Hantavirus is a perfect example of one of those. And so increasingly in our work, we're finding that when the environment is healthy, when we keep those ecosystems healthy, those ecosystem processes are occurring in the way that nature intended. We have many, many fewer disease risks and many, many fewer disease spillover events.

Daniel: Interesting. So I think one thing that's maybe surprising to some people, but talking with you, it seems pretty obvious, that like one approach to studying climate change or thinking about climate change is to think about it through a lens of public health, of environmental health. Do you encounter people that find that surprising, or that's a new idea for them. That these that climate change and environmental health and human health are connected.

Danielle: It's really surprising to me to hear and see how many people have not thought about that connection. In every aspect of the way in which climate change impacts the environment, has a similar impact on human health. And yet studies have shown that few people are aware of those impacts, even if they've personally been impacted by a climate disaster or climate emergency. Because when people understand climate change as an impact to their daily lives and their personal health and their family's health, I think it really helps people to understand why it's so important they take action. And it also helps to clarify the ways in which they can personally take action in their local community, in their home and the environment around them.

Daniel: Yeah. Do you think it's helpful for us to define the difference between health and disease?

Danielle: I think that Western medicine, and my own profession, has focused heavily on disease because it's really easy to see. It's very easy to measure. We have specific tests for specific diseases, and oftentimes it's it's something that we can directly treat. Health is a really difficult thing to measure. Health is not simply the absence of disease, but an individual's ability to thrive within the environment that they exist in, whether it's a human or an animal. And it's therefore a lot easier to understand why health is more directly impacted by climate change than disease per se. Even though we do know that climate change dramatically influences the rate, the types and the severity of infectious diseases. But again, health is much broader than just disease, and therefore the impacts of climate change are much broader than just disease.

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Daniel: What are some examples of climate change really impacting wildlife health and wildlife disease that you've come across in your work?

Danielle: Climate change can influence the actual reproduction of a bacterium or a virus. Under warmer temperatures, or higher or sometimes even lower amounts of precipitation, certain bacteria and viruses can replicate faster, to a higher level, or for a longer period of time. Mosquito-borne viruses are a perfect example of this. When you have a longer, warmer summer, mosquitoes can replicate much more quickly and rapidly, they're present for a longer period of time throughout the year, and those viruses within those mosquitoes can also replicate more rapidly under those warming temperatures. We're also seeing that infectious diseases are changed under climate change because of the ways in which the environment influences where those animals thrive and survive. Avian malaria in Hawaii is a perfect example of this. While neither the mosquitoes nor the the parasite that causes malaria are native to Hawaii, they have become endemic in bird populations and in mosquito populations there. Prior to the warmer temperatures we've seen under climate change, a lot of the native bird species were able to only survive and evade malaria at very high elevations on the mountains in Hawaii. With climate change, those mosquito vectors are moving up in elevation, and those native bird species that are extremely susceptible to malaria, because they didn't evolve with this non-native parasite, are dying out from malaria. And as the mosquitoes move up, there's fewer and fewer refugia, or safe places, for those birds to survive and hide from both the mosquito and the malaria parasite. And we've seen a lot of those native birds go completely extinct because of this parasite. In fact, there's a variety of studies show that there's probably only a few more years left for some of these native bird species to survive without going extinct, if we don't take action now to eradicate that non-native mosquito and that non-native parasite that's present on the island.

Daniel: Wow. So basically, in the case of Hawaii and the birds there, it's a story of climate change and a story of invasive or non-native species in that the mosquitoes and the malaria is historically wasn't there. But this is -- generally, all around the world, what's happening is as the climate warms, these mosquitoes and the diseases they carry are able to spread into new places and impact more people and new species of wildlife as well. Is that right?

Danielle: That's absolutely correct.

Daniel: So we're seeing the potential for these mosquitoes to expand their ranges. Does their range contract alongside, too? As it gets hotter and hotter, they can move to higher elevations and farther north, but then does their the southern end or the lower end of their ranges shrink at the same time? Or are they able to tolerate the heat better?

Danielle: For for many species, absolutely. There is not necessarily an expansion of range. Oftentimes, it's just a shift in the range in which these organisms can survive. However, it's not just climate change that's happening on the landscape. It's also human development of landscapes. And humans create microclimates that are oftentimes much more conducive to having these parasites, whether it's ticks, mosquitoes, pathogens themselves, survive. So, for example, here in Colorado, on the Front Range, we have a lot of irrigation because people like green lawns, they like having trees that might not otherwise be able to live on this landscape. And when we have irrigation, we know we have dramatically increased rates of mosquito-borne disease, such as West Nile virus. And so we have, by altering the landscape, changed the way in which these pathogens can survive and interact. And you have kind of a one-two double whammy of that land-use change that's expanding the range, as well as those, those changes from climate change that are expanding the season under which these pathogens can thrive. But I want to be clear it's not always a unidirectional: more disease because of climate change. If we're seeing decreases in precipitation or longer periods of time between which we have rainfall events, that can impact the survival of of ticks. And so it's not always that climate change is causing more pathogens to occur on the landscape. And maybe in some circumstances that's causing them to contract their range or be present for a shorter period of time. But at the end of the day, humans and animals evolved under very specific, discrete conditions. And when we have more rapid and more unpredictable changes in weather and conditions, this means that we are more susceptible to diseases. And diseases are more able to opportunistically take advantage of new niches.

Daniel: What I'm hearing you say is that, yes, the shift in mosquitoes and disease, the shift in range and the lengthening of the season, those are concerning. But maybe something that's understated here then is that climate change is just increasing kind of the chaos in the system, and the complexity, which makes all of this just harder to manage.

Danielle: That's a perfect way to put it.

Daniel: Well, let's talk about the pika research, then. What's happening with pika and climate change and disease?

Danielle: So pika are amazing little creatures that have evolved to fill a very specific niche at these very high elevation sites. So a big study that we have going on now is to understand how climate change may be influencing the other small mammals that are moving up to those higher-elevation sites. Because they're seeing warmer temperatures up at those higher-elevation sites, they're able to survive and interact with new populations and they're often bringing their diseases with them. And indeed, there's previous studies that have found, you know, certain species of small mammal that are known to be impacted by plague and carry fleas that can very easily and readily transmit the plague bacterium. They are now found at higher elevation sites where pika are also found. So we're really interested in looking at how those warmer temperatures may be driving new species to interact with pika, and they may be bringing the diseases that could potentially kill pika with them.

Daniel: Wow. So if someone hasn't heard of pika before, pikas are these really cute little mammals that are related to rabbits. So they're not really like mouse-like, they're much cuter than that. Size of potatoes, they love to live under the rocks high in the mountains and then like store up flowers for the winter because they don't actually hibernate. They don't sleep through the winter, right? They just hide under the rocks and eat their hay pile all winter long.

Danielle: Yeah. An adorable squeaky potato is a great way to put it.

Daniel: [laughs] So to stay warm in the winter, they hide under, you know, heavy, deep snows. And that keeps it, you know, it doesn't really get a whole lot colder than freezing point -- than 32 degrees. The snow actually insulates them from the colder air blowing around at the tops of the mountains. But then if you have changes in the amount of snow you're getting, or how warm the winters are, you might get less snow. And that could really hurt their ability to survive through the winter. So that's the general climate impact facing pika. But now you're describing something much more nuanced and complicated, and that is all these other animals, squirrels and mice and all kinds of little creatures that that have fleas, that have potentially diseases. And they're moving up the mountains because it's getting warmer up there and it's nice. And so they're interacting with the pika more, potentially sharing diseases. Am I getting that relationship right?

Danielle: Exactly. And I think it also really highlights what we talked about earlier, that interplay between health and disease. It's not just about whether or not a disease is present, it's how healthy is that population to begin with? How resilient is it to changes in its environment, in the introduction to new diseases? When you both have the loss of snowpack happening, as well as the introduction of a new disease, you're much more likely to see declines in that population because they don't have that resilience.

Daniel: So it's like, yeah, bringing some new diseases into a population of pikas isn't great, but so long -- if they're really healthy, then maybe that's not a big deal. But if they're really stressed and not very healthy because they've been freezing all winter long and really struggling, well then disease is going to hit a lot harder when it shows up.

Danielle: It's sometimes even native diseases that these populations may have evolved to handle or withstand the impacts of these diseases under normal conditions. But maybe under the land use changes that humans are causing, combined with climate change, those native diseases that they've previously evolved some sort of equilibrium or balance with are now having really detrimental impacts.

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Daniel: Well, let's shift a little bit and talk about some of the impacts of climate change on human health that are a little, a little different than what we've been talking about. One of the primary examples is that well, burning fossil fuels like driving a car or running a coal power plant, that produces, in addition to greenhouse gases which are warming the climate, it's also producing air pollution, which has a big impact on human health. And I'm wondering if you could kind of lay that out a little bit. How does just the use of fossil fuels, aside from causing climate change, how does that impact human health?

Danielle: I don't think we can state strongly enough the negative impact of fossil fuel combustion on human health. Because that pollution that's created, we're directly breathing it, because it's often created in the communities in which we live. It's our actions -- driving our car to work, heating our homes, transporting the food that we eat to the grocery store -- all of those things are happening in the places that we live and work, and therefore we're directly exposed to a lot of this pollution. It's estimated that the combustion of fossil fuels and the resulting air pollution is responsible for anywhere from 8 to 10 million deaths every single year. That is more than AIDS, malaria, and tuberculosis kills -- combined -- every single year. And so it's really easy to make the business case for for clean energy, for for stopping climate change, because even if we're only looking at the direct health impacts of fossil fuel combustion, we can pay for clean energy. We can pay for that transition away from fossil fuels, away from combustion engines, just from the health care savings that we see. By stopping all of those premature deaths, it's decreasing our lifespans. No matter where you live and who you are. Although obviously individuals that live in more polluted communities, which unfortunately is often disadvantaged populations, whether it's people that live in rural parts of the country, people of color, people with lower income, those people obviously you see the brunt of it to a greater extent than more privileged communities. But even people in privileged communities are dying at much faster rates because of exposure to air pollution. It can get very deep into our lungs and it can cross into our bloodstream where our blood is pumped throughout our body. And those little tiny particles of pollution get lodged in our tissues. One of the most direct impacts is when it's lodged in our brain where it can cause a stroke or it leads to dementia. We see much higher rates of dementia in communities with higher rates of pollution. Or it can be in your heart or your blood vessels and it can lead to a heart attack or other types of cardiovascular disease. And so you've certainly met someone, know someone, have personally been impacted by stroke, heart attack, cardiovascular disease. All of those diseases are much worse and much more common because of fossil fuel combustion, because of our exposure to air pollution. And that's really just the start. There's a myriad of other ways in which that burning of fossil fuels impacts our health, but those are the most obvious.

Daniel: Wow. So if someone you know has a stroke, the medical report probably isn't going to say anything about air pollution because we're just not looking into the details that carefully anytime someone has a stroke. You know, we're just trying to help them get better and recover. But in reality, the air pollution is contributing at least some amount to that likelihood of a stroke happening.

Danielle: Absolutely. It's, you know, similar to the interplay of health and disease, we focus on that end result, that stroke. We focus on that disease, but we're not thinking enough about all of those factors that caused that stroke to occur in the first place. And exposure to pollution is is a really, really important one. There was, however, recently one of the first death certificates that had climate change listed. It was in, an I believe, a young person who had died from an asthma attack. And asthma is a much more direct, much more obvious way in which climate change and the burning of fossil fuels impacts our health. But there's there's many less obvious ways and many more insidious ways than simply dying from an asthma attack.

Daniel: It's difficult to parse out how much worse their particular case of asthma is because of burning fossil fuels. But it's certainly exacerbating and worsening these breathing and lung conditions that people might already have or might not already have.

Danielle: And it's not just direct exposure to fossil fuel combustion. It's also those secondary impacts of burning fossil fuels. So under these warmer temperatures, we know that wildfire is dramatically increasing. You know, and the the particles that are released during a wildfire event are having that secondary and compounding impact on increasing rates of asthma, increasing hospital admissions, increasing stroke, increasing heart attack. So it's oftentimes multifactorial, but increasingly, those events are linked to impacts of climate change. We know that, you know, somewhat surprisingly, increased precipitation from climate change in some parts of the country are increasing pollen counts and worsening asthma and other types of air pollution, whereas in other parts of the country, such as the desert southwest, those increased droughts and increased temperatures are worsening the dust, sometimes worsening fungal pollen spores that can cause different infectious diseases such as Valley Fever and worsening the rates of asthma, the rates of of general lung disease and other impacts because of those warmer temperatures.

Daniel: So here in Glacier, what what's probably happening is we're getting longer summers, warmer summers. So there's allergy season in the summer and the season in which plants are pollinating. Like that's lengthening, too. So if you're allergic to tree pollen, like when there's just longer time periods with that pollen in the air.

Danielle: These are oftentimes synergistic, especially when you have warmer temperatures. When the body is overheated, when we have higher, hotter ambient temperatures, it's a lot harder for our body to respond to especially those cardiovascular insults. We see much higher rates of cardiovascular disease and cardiovascular attacks when you have these compound exposures. So it is, as you said earlier, it's just increased chaos.

Daniel: Yeah, increased chaos because it's one thing if your allergies are way worse because of the pollen or your asthma is way worse because of the smoke. But then you have to add on top of that, like, oh, also a heat wave and you don't have air conditioning. Like now you're suddenly really susceptible to like just a common cold, I would think is going to hit way harder when your body is run down from heat and smoke and everything.

Danielle: And we saw this with COVID. We saw that populations that were experiencing greater amounts of air pollution had much more severe rates of COVID-19 disease and death. We know that when your body is responding to pollution and responding to particulate matter, it's much more difficult to fight off infectious diseases, even things such as as seemingly benign as the common cold.

Daniel: Wow. Well, let's talk about the heat, then, because ultimately, that's what we most typically associated with climate change, is burning fossil fuels, is releasing greenhouse gases, and that's heating the planet. And heat is ultimately very dangerous.

Danielle: Most folks are often surprised to hear and learn that heat kills more people than any other severe weather event. And it isn't just direct heat exposure, just as it isn't direct fossil fuel pollution exposure that kills people. Repeated exposure to high temperatures in which your body's not able to cool itself well can cause a lot of long term health impacts. It can decrease kidney function. There's some studies suggesting it may influence the development of other chronic diseases, such as diabetes. It can have long term impacts on your cardiovascular system, and it can influence your ability to withstand those severe heat events in future years. And so it's not just simply did you survive that extreme heat event that you saw. It's what long term consequences are occurring to your body when when you have these, these heat exposure in these extreme heat events.

Daniel: There's two themes emerging in this conversation so far, Danielle. One of them is that the impacts of climate change on health are not evenly distributed. They're impacting some people more than others. Another theme that's emerging, that if it's not obvious already, is that none of these impacts are acting alone. They're all interacting together and exacerbating and influencing each other. Well, I want to ask you something more about heat. In Phoenix this summer, they had like almost the entire month of July over 110 degrees Fahrenheit. And that's incredible. Glacier National Park here in West Glacier, I think our record high temperature ever is 100 degrees Fahrenheit. So it's just it doesn't get that hot here. But I'm guessing that you can say more about how it's not necessarily the number that causes health issues. It's not the exact temperature. There's other factors, right?

Danielle: It is often unexpected heat that causes the worst health impacts and outcomes because people are neither behaviorally able to adapt -- maybe you didn't bring sun protection, maybe you didn't plan your hike so that you can take shade breaks, maybe you didn't bring enough water -- as well as physiologically adapt. When your body is gradually exposed to increasing heat, it's able to cool itself more efficiently over time, provided that it has the resources that needed it needs. So it's unexpected heat that's oftentimes the greatest killer. But what our study found was where we had the most severe health impacts and the most number of heat illness events and deaths was in the shoulder seasons. It's when people didn't expect the heat that they suffered the worst.

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Daniel: So far, we've talked about impacts of climate change on wildlife health and disease. And we've talked about the impacts of climate change on human health and disease. And now I was going to ask you, let's talk more about where those overlap and intersect, how human and wildlife and environmental health are really inseparable and tied together. Do you think the best examples might be like Lyme disease, hantavirus, West Nile? Should we talk about those?

Danielle: I think those are some of the the most salient examples of how human, environmental and wildlife health are interlinked. However, they're not the most powerful examples in terms of overall health benefits or overall health detriments. Lyme disease and West Nile and hantavirus are all infectious diseases that can be spread from wildlife and or insects to humans, and oftentimes vice versa. And we know that each of these diseases occurs at higher rates and spills over to humans more often when there are aspects of that environment that aren't healthy. We know, for example, West Nile virus occurs at the highest rates in the human population when there are the least number of bird species present and when there is not a very diverse community of wildlife present. It's something that's been referred to as the dilution effect, although that simplifies it quite a bit. It's much more complex than that. But it's the idea that when you have diverse wildlife populations that are present in healthy ecosystems, they essentially can dilute out that disease because they're not all susceptible to it, and therefore it can't simply amplify by passing from one animal to the next to the next. And that means that when you don't have that complete community of birds present, when you don't have that diverse assemblage of wildlife species present, you can see greater rates of some of these diseases. Lyme disease is another example of that. We know that when you have more predators present on the landscape, you have lower numbers and lower rates of transmission in the mouse populations, either because those predators are eating that mouse species that is uniquely capable of maintaining high numbers of the Lyme disease-causing bacteria, or oftentimes because those mice aren't as often to go out there and transmit disease more readily because they're afraid that a predator is watching them. And that's why when we have more natural predators present, when we have a more diverse wildlife community present on the landscape, we have lower rates of Lyme disease in those human communities and that part of of the environment. Wow. So we know that when that ecosystem is diverse and healthy, we generally have lower rates of disease transmission.

Daniel: That's really amazing. To underline that, you're saying that more biodiversity results in less disease for wildlife and people.

Danielle: For many diseases yes, that is -- and generally that is the case.

Daniel: Wow. Can we dig into each of these a little bit then? What is it about having more birds that helps with West Nile disease?

Danielle: Yeah, this is a great question and a really important example of this mechanism of of how biodiversity protects us. There are certain bird species that are really susceptible to West Nile virus, and those bird species can make a whole lot of virus in their bloodstream when they get infected. Corvids, which are things like jays and crows, are examples of birds that that make a whole lot of virus when they get infected. And that's oftentimes why they die from West Nile virus. But before they die, they can infect a lot of mosquitoes, because every single time a mosquito takes blood from that animal, they can pick up a ton of virus because it's at such high density in the blood of that bird species. Compare that to other types of songbirds that are probably more rare, probably don't like living around humans to the same extent that those corvids species do. They may get infected with West Nile virus, but they're much less likely to die from it, and they don't make as much virus when they have it or they never get it in the first place. So when you have those songbirds present that aren't very capable at transmitting West Nile virus, you essentially stop those mosquitoes from feeding on those those jays and those crows and those other species that are really good at transmitting it. And therefore, a fewer percentage of the mosquitoes in that population are going to be transmitting and carrying West Nile virus. The thing is, those species that are really good at transmitting West Nile virus are some of the most resilient to human disturbance. That's why those are the birds you see in neighborhoods, because those are some of the only ones that are tolerant of night lighting that occurs oftentimes in human developments or the noises that occur or the very, very impoverished numbers of trees and diversity of of plant species. A lot of those songbirds need more food than is present in an urban landscape, and therefore they can't live there. And so that's why having more bird species present, as we see in more diverse communities, is associated with having fewer human infections with West Nile virus.

Daniel: This is kind of blowing my mind. And so when we're talking about these diseases and the overlap between wildlife health and biodiversity and human health and human disease, the climate impact is not quite as direct as some of the other things we've talked about, but it's still a factor in that climate change is disrupting the life patterns and the existence of a bunch of these animals and changing the amount of like generalist species, like ravens versus sensitive warbler species that are being impacted by climate change, am I understanding that. Right?

Danielle: Absolutely. And I think it's probably easier to see climate impacts in these wildlife diseases and populations if instead of looking at the negative side of things, we look at the positive side of things because we know that when you have more tree canopy present in a location that's supposed to be forested, you have much greater rates of biodiversity. So more species of birds present, so less or lower rates of West Nile virus transmission occurring there. And you're more resilient against heat illness because you've got shade there, you have evapotranspiration happening from those trees. So they create cooler, more humid micro environments that help your body cool and all of those other species that are just as susceptible to heat illness oftentimes as humans are. It cleans the water. It means you're more you're less susceptible to flooding because the roots of those trees will take that water away. It regulates our environment in so many ways that it both decreases the risk of a lot of these infectious diseases, as well as protects us from severe heat, extreme weather, extreme flooding, drought, etc.. And so, you know, it's it's not just, again, about disease. It's it's really about health writ large.

Daniel: At the end of the day, those diseases are not our greatest killers. They don't have the greatest health impacts. And other infectious diseases where biodiversity can regulate or reduce the rate of disease transmission may have be more important from a number standpoint, even if the example by which biodiversity regulates disease transmission isn't as obvious.

Daniel: Are you saying that, well, hantavirus, Lyme disease, this is kind of scary, but ultimately, like from a public health perspective, asthma, and air quality, that kind of stuff is just way more impactful. Way more important.

Danielle: Exactly. Exactly. When you look at the top ten killers, not just in the United States, but globally, they're not infectious diseases. They're chronic diseases, they're cancer. They're diseases from air pollution. They're, you know, factors and health impacts that are influenced both by climate change increasingly, as well as access to nature. [drumbeat plays to mark a transition]

Daniel: So you're describing the health and disease benefits of basically just having more greenspace, having more trees and grass around where you live. Right.

Danielle: Most people can probably think about the way in which being outside might make you feel better. It's not just a feeling. We know that when you are exposed to nature, even if it's in short periods of time, very small segments or what we would think of as not very natural nature, such as a dense city park or even house plants, it can have really profound physiologic impacts that last for quite a long time on us. We know that kids that are exposed to nature, if they walk through a tree lined street on their way to school, they're going to concentrate better. They have better immune function, they have better recall and memory and and better behavioral characteristics. There are studies that have found that kids that are exposed to nature on a regular basis can sometimes even eliminate the need for medication to deal with things such as attention deficit hyperactivity disorder, attention deficit disorder, simply from exposure to nature. We also know that we have significant increases in, for example, natural killer cell function and other immune markers when we are exposed to some of the phytochemicals that trees release, or simply exposed to greenspace, our immune system is better able to deal with pollution as well as infectious diseases when we're exposed to nature. We also know that there's a lot of mental health benefits, not just memory and mental function, but also decreased rates of anxiety, depression, lower rates of crime in communities that have green space present. And all of these is really has been found to be a direct measure or impact of of the presence of nature, even when we control for things such as socioeconomic conditions present in that environment, other other factors that can influence any of these outcomes. You know, regardless of of what your background is or where you live, there's a health impact of nature exposure that we can see if we're increasing the amount of nature you're exposed to.

Daniel: Wow.

Danielle: Yeah. And I think this is really important because while diseases such as West Nile virus, hantavirus, Lyme disease are important, they actually don't kill that many people. They can have a devastating impact on your life if you have some of those long term sequelae of Lyme disease infection. But in reality, the impacts of those diseases pale in comparison with a lot of the chronic diseases such as depression, such as substance abuse, such as suicide, such as cardiovascular disease and cancer, these chronic diseases that kill far more people than those infectious diseases. But those chronic diseases that can be alleviated, if not completely cured or prevented if we have more nature present in our environment and if we have access to nature. We know that people are more likely to participate in healthy behaviors when they have more nature present in their community and environment. We know that people are more likely to be connected to others and their community when they have more greenspace present. And that dramatically increases life span and lessens your risk of dying from any type of extreme event, severe weather, emergency fire or otherwise. Because people are going to check on you. You're less likely to die of diseases of despair such as alcoholism, drug use disorder, and other forms of of mental illness deaths when you have exposure to nature and a stronger, more closer knit community. And so it really influences and improves our health in a variety of ways. Those impacts are much harder to measure than diseases from infectious causes, but they're no less real. Just because we maybe can't can't measure them in the same way.

Daniel: And so oftentimes, like defining what is nature is messy or complicated, but in this case, we're like really loosely defining it, I think, right. Like it's we're talking about just having grass and trees and plants around you. That's what you mean by exposure to nature for the most part. Right?

Danielle: Yeah. And in fact, one of the first seminal studies showing this effect simply looked at whether or not hospital patients recovering from gallbladder surgery could see nature outside of their window, or if they were on a side of the hospital that looked out at other buildings. And they found much faster rates of recovery and better outcomes in those patients who had views of trees outside of their hospital window. And so there hasn't been that much work done to really quantify what types of nature have what types of impact. But the good news is the bar is pretty low. Any nature, whether it's native or not or pristine or not or large or small, is going to have some positive benefit on your mental health, on your physical health, and your community health, and your chance of living longer and healthier and happier. And studies that look at infectious disease, studies that look at chronic disease, studies that look at school performance, anxiety, the list goes on and on. And the other thing that's really important about this is a lot of these diseases are impacted by climate change, but a lot of the benefits of nature go beyond some of the things we've just talked about to, again, reducing your risk of extreme heat, reducing your exposure to air pollution. Trees are one of the best sources of of air filters, right? Trees clean our air to a greater extent than nearly any other type of technology, and trees draw down carbon. They both help us adapt to climate change as well as help to reverse or stop some of the climate warming pollution, pull it down back into the ground so that we're not still seeing the heating impact of that carbon that's in the air. So nature is is so beneficial on so many so many levels. And climate change is really compounding a lot of these diseases that we're exposed to, a lot of these health impacts that we're exposed to. But access to nature can both have a direct impact on our risk of those diseases, as well as reverse or mitigate some of our future risk by by helping us adapt to and mitigate climate change directly.

Daniel: And to be clear, you're not talking about like some special whitebark pine tree in the top of a national park. You're talking about literally any tree is improving our air quality and health while also drawing down carbon along the way.

Danielle: Yes. And this is actually a really important point because the tree that's going to have the greatest influence on your health is the one that's closest to you. But it's local nature that has the greatest health impact because you have the greatest exposure to it. It doesn't have to be large scale. It doesn't have to be as big or beautiful as you'd like it to be. Any nature is going to have a positive health benefit for you if you're exposed to it at a higher rate.

Daniel: Not everybody has the same access to a neighborhood filled with trees and streets lined with trees. Some neighborhoods have more than others.

Danielle: And this is why those health impacts of climate change fall very unequally on communities and hit those vulnerable communities with the least resources. Most significantly, because those communities are less likely to have tree canopy, you're both less likely to have the money or the housing for air conditioning or well sealed housing that can keep that wildfire smoke out, and you're less likely to have tree canopy that's going to clean up that pollution that's there or shade your house so that you're less impacted by the lack of air conditioning during a heat wave. Greenspace is one way in which we can dramatically improve the health of those vulnerable communities, because there's both the really, really beneficial health aspects of having that exposure to greenspace, as well as that really significant need to help them adapt to warmer temperatures, to more air pollution, to more diseases present, to more flooding, to more drought. Trees are going to help with all of those things, and they're beneficial whether or not you're experiencing one of those extreme weather events.

Daniel: So altogether, it's like kind of scary to really realize like how unhealthy and how negatively our environment is being impacted by climate change. But it's also kind of inspiring or exciting that like there's so many benefits to our health from fostering a healthy environment and addressing climate change. That like we have the solutions and those solutions for a lot of these is just like engaging with and encouraging more greenspace in your own neighborhood.

Danielle: And even better, if they could be a food source to you or to to local wildlife, which you know is another impact of climate change we haven't talked about is food scarcity and food insecurity, because we're having more droughts and heat waves and greater chaos. You can't grow crops very well if you don't know whether or not the rain is going to come or how hot that temperature is going to be that summer. And so having more nature present and more types of nature present is going to make you more adaptable and more resilient. And the other really important aspect of having more nature present is that it is one of the only things that the American public universally supports. It does not matter your political views, your economic background, your your ethnic background, everyone universally, over 93% of Americans support protecting more greenspace, whether it's national parks or otherwise, for the benefit and well-being of other Americans. And so it's something we can all get behind as as a climate solution, as an equity solution, as a health solution of having more greenspace present. And if we use that greenspace to to also then, you know, grow local food or have more educational opportunities for kids or have more spaces for us to connect with each other, we're going to see a myriad of other health benefits and resilience benefits against some of these climate changes in the future.

Daniel: Well, this is all been incredible. Thank you, Dr. Buttke, for taking the time to come and chat with us about this.

Danielle: Thank you for the time. But at the end of the day, the the story is is really one of hope and and nature, the health benefits of nature. The best way for you to have an impact. The best way for you to take climate action is right where you are, influencing the people that will listen to you most readily and most willingly and in the way in which you you best know how. Any action you can take is going to be beneficial, but it's going to be most beneficial if it's it's local to you and in with people that that trust and are more likely to follow in your footsteps. And again, everyone supports more nature. Everyone supports more green space. So it's a really good place to start.

Daniel: We have so much to gain by addressing climate change. I love that.

Danielle: It's important to recognize that there's extreme disparity in this country in particular, and access to greenspace and access to shade and access to parks. And it's not simply about what zip code you live in and whether or not you have money to take that vacation and travel to to a national park. It's more about the ways in which our cities were designed and developed that excluded people of color, in particular from living in certain neighborhoods and parts of certain cities because of institutional and structural racism that existed. We know that the practice of redlining prohibited people of color from owning homes in certain parts of the city that were more likely to have greenspace and parks present. And that's why today, one of the thing that predicts your likelihood of having shade or having urban tree canopy or access to green space is sadly the color of your skin. This is a an absolute health disparity in addition to just simply being wrong that we really need to to to remedy not only because it's the right thing to do, but because it has dramatic health benefits and it helps those vulnerable communities adapt to and mitigate climate change in a way that they need it most.

Daniel: So, Danielle, some of what you're describing is the benefits of green space, not just on human health and mitigating human disease, but also just improving like mental health to being in green space. And I'm also curious to see what you think about the benefits of mental health, of like taking action, doing something in your community about green space or about climate change. Like, does that have an impact on mental health or any other kind of health?

Danielle: I think oftentimes we think about it backwards. It isn't that if you have hope, you take action. It's that if you take action that brings you hope. Taking action actually dramatically improves your mental health. And oftentimes people don't know where to start or where to act. The good news is, is that anything you can do in your neighborhood is going to have the biggest impact. And any action you're taking in your local, local neighborhood or community is also more likely to have that positive impact on your health. If you're advocating for a park, if you're planting trees, if you're starting a community garden, we are going to have so much more hope when we take action and we're going to have such a greater impact when we do it through nature based solutions, because they have health benefits that extend far beyond the direct impact on climate and health benefits or impacts. We are increasingly dependent on our local communities to meet our needs, to take care of each other, to support each other through these extreme weather events and these climate impacts and action that we can take, such as improving greenspace locally, is going to make our community more prepared for these events. It's going to provide us a resource that helps mitigate and reduce the impacts of those severe events. And it's just going to make us healthier, happier and more resilient long term. So it's it's really, I think one of the best ways for us to find hope is by taking action to find those nature based solutions where you live and work, because they'll have the greatest impact and you'll see those benefits quite clearly.

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Daniel: Yeah, that's great. We have so much to gain by taking action to address climate change from creating more greenspace. I love it.

Peri: Headwaters is funded by donations to the Glacier National Park Conservancy. As an organization dedicated to supporting the park, the Conservancy funds a lot of sustainability initiatives from solar panels on park buildings to storytelling projects like this one. The Conservancy is doing critical work to prevent the worst impacts of climate change. You can learn more about what they do and about how to get involved at Glacier.org. This show is created by Daniel Lombardi, Michael Faist, Gaby Eseverri, and me, Peri Sasnett. We get critical support from Lacy Kowalski, Melissa Sladek, Kristen Friesen, and so many good people with Glacier's, natural and cultural resource teams. Our music was made by the brilliant Frank Waln, and the show's cover art is by our sweet friend Stella Nall. Check out Frank and Stella's work at the links in the show notes. Besides sharing this episode with a friend who might appreciate it, you can help us out by leaving a rating and review in your podcast app. Thanks for listening.

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