Fifth National Climate Assessment, Southwest Chapter: Health, Water, Agriculture, and Wildfire

We continue our discussion of the Southwest Chapter of the 5th National Climate Assessment (NCA5). Each Chapter of NCA5 is organized around Key Messages. This month we interviewed the lead authors of four Key Messages in the Southwest Chapter, covering human health, water, agriculture, and wildfire. Each author shares what they would like people to know and what they found hopeful or encouraging within their Key Message topic.

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NCA5 Atlas

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DOI Southwest CASC: https://www.swcasc.arizona.edu/ 
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Transcript

Welcome to Come Rain or Shine, podcast of the USDA Southwest Climate Hub and the DOI Southwest Climate Adaptation Science Center for Southwest CASC, operated by the USGS. I'm Sarah LeRoy, Research Coordinator for the Southwest CASC. And I'm Emile Elias, Director of the Southwest Climate Hub. Here we highlight stories to share the most recent advances in climate science, weather, and climate adaptation and innovative practices to support resilient landscapes and communities.

We believe that sharing some of the most innovative, forward thinking, and creative climate science and adaptation will strengthen our collective ability to respond to even the most challenging impacts of climate change in one of the hottest and driest regions of the world.

The contents of this podcast are for informational purposes only and should not be interpreted as endorsement for any of the products, technologies, or strategies discussed.

Sarah LeRoy: This month, we are continuing our discussion of the 5th National Climate Assessment, which is the U. S. government's preeminent report on climate change impacts, risks, and responses. It is a congressionally mandated interagency effort that provides the scientific foundation to support informed decision making across the United States.

Today, we hear from three of the authors contributing to the Southwest Chapter. Each chapter is organized around key messages. Today we will be discussing four key messages in the Southwest chapter related to human health, water resources, agriculture, and wildfire in the Southwest. 

First, we'll be talking with Dr. Jennifer Vanos about the key message related to human health in the Southwest. Dr. Vanos is an associate professor in the School of Sustainability at Arizona State University where her research focuses on extreme heat, thermal comfort, and air pollution, and health impacts on vulnerable populations such as children and athletes.

She wrote the Human Health Key Message, which supports the overarching theme that climate change compromises human health and reshapes demographics. Dr. Vanos, what would you like people to know about the key message related to human health in the Southwest? 

Jennifer Vanos: Well, first, thank you for having me. I'm really excited to talk about this and share some of what we learned in this process.

But when we think about the human health message, it's pretty complex when we look at all of the different factors that can affect human health. And in the southwest is going to be unique from what we see in the northeast, for example, but I really think it's important for people to think about how we can make those linkages between human exposures to various climatic factors, as well as indirect factors that are part of that, um, like thinking about drought linked to heat and air pollution, and which of those are affected by a change in climate in the first place.

So if we're seeing trends in increasing heat along with a more at risk population that are exposed to heat, then we have two problems occurring in tandem that are exacerbating health issues, and that are linked to these extremes, and then there could be confounding factors with air pollution, with socio-demographics, and so forth.

So this is where we know that based on studies on socio-demographics, physical health status, physiology, and vulnerability, that certain individuals are more at risk to these increasing climate change impacts that we're seeing. Some of these people might include older adults, outdoor workers, and people with low income, and those are part of our key message there of what groups do we really need to be paying attention to, to help with resilience and coping capacity.

These groups are also increasing in numbers with aging, population growth, and migration. So there's an increasing need to reduce risk and exposure, enhance resilience and adaptive capacity, all in concert with reducing climate change.

I think another piece that I want to also put a pin in and acknowledge is how important it is to have good health data, it's absolutely vital in understanding these issues. So one of the reasons that we can say there is high confidence that extreme heat or drought or flooding and wildfires negatively impact physical health is because we have the health data used in studies that can directly link to these exposures and challenges.

And future work really needs to start to focus on attribution studies so that we can make statements like climate change caused x percentage of these deaths versus what would have occurred if climate change didn't exist in our world. Right now, we don't really have enough climate and health attribution studies looking at this, um, and this is something to look for in the future as we get longer and longer years of health and climate data put together.

Sarah LeRoy: Great. Thanks, Jenny. Our second question for you related to this key message of human health, what do you find hopeful or encouraging from this key message? 

Jennifer Vanos: Yeah, I think when I think about this question, I can think about our key message, but I can also think about the entire report from the National Climate Assessment.

So what's hopeful and encouraging to me is that we do see that local, state, and federal adaptation initiatives are working to respond to these environmental health impacts, and we do have high confidence in that and what we see on the ground. We need these adaptation responses at these various levels to manage the hazards that we see today.

Um, but these hazards we have to acknowledge are being exacerbated by climate change, so these initiatives at the local, state, and federal level acknowledge that these are today problems, not future problems, but that actions that we take today will help both current and future generations. The report and our chapter also, I think, does a nice job at centering equity, especially health equity and pushing, pushing people to dismantle the barriers to reduce exposure while creating opportunities along the way.

This is something that we can bolster throughout the country, I think, but it requires a combination of both accelerated mitigation and adaptation. 

And then finally, I think it's really encouraging to see that there's this emphasis on local adaptation planning in a given place rather than using sweeping suggestions. That might not work everywhere. So we recognize that cultures and different climate types across the Southwestern country exist and that we have to um, account for those and not use this one size fits all approach to tackling climate resilience and adaptation. So we really hone in on more place based approaches.

What's working in Phoenix? What's working in Tucson? What's, how is that different from California or Colorado? And then some of the best, acknowledging that some of the best ideas actually come from the bottom up in communities. 

Sarah LeRoy: Excellent. Well, thank you so much for speaking with us today. 

Jennifer Vanos: Yeah, thanks so much for having me.

Sarah LeRoy: The next key message we are discussing is related to water resources in the Southwest. Dr. Elizabeth Koebele is an Associate Professor of Political Science at the University of Nevada, Reno. Her work focuses on environmental policy with a focus on collaborative environmental governance, water policy, and management in the western United States, disaster policy, and public policy theory.

Dr. Koebele served as one of the authors on the Water Resources Key Message, which supports the overarching theme that drought and increasing aridity threaten water resources in the southwest. Elizabeth, thanks for joining us. What would you like people to know about this water resources key message?

Elizabeth Koebele: Thanks so much for having me on the podcast today and for highlighting the water resources key message from the Southwest chapter. There are three major things I'd like people to know about this key message.

So first, the Southwest region is generally becoming more arid, and this means there's less water available for people and the environment. Well, those of us that live in the Southwest have experienced intense and prolonged drought in the region over the last few decades, something we've started to call mega drought. Science suggests that we're actually seeing a broader, more long lasting drying trend than what we typically associate with the term drought, and this is what we call aridification.

Related to this, and contrary to many people's expectations, the Southwest region isn't drying because it's receiving less precipitation than it has in the past. In fact, in some places in the Southwest, total precipitation may even increase as the climate warms. Instead, rising temperatures are really the culprit behind our region's water management challenges.

This is because many areas of the Southwest rely heavily on winter snow for water supplies. And warmer temperatures create smaller snow packs that melt earlier in the year. Warmer temperatures can also lead to more evaporation and drier soils. So taken together, these and other changes are likely to reduce our surface water flows and impact how our groundwater aquifers refill.The environment also gets thirstier when it's hotter and water demand increases across sectors. 

So these changes are important not only because they can heighten the risk of water supply disruptions in the Southwest, but they also challenge our ability to generate hydropower and have potential negative implications for our region's economy and our sensitive ecology.

But fortunately we've seen major scientific advances. since NCA4 in understanding these dynamics and projecting how they might intensify in the future as temperatures warm, which can help us develop strategies to better alleviate their impacts on society. 

Second, although we talk a lot about drought and aridification in the Southwest, science also suggests that we are likely to see increased flood events in this region under a warming climate. So some of the flooding may result from the more rapid snowmelt that I just talked about, once again, caused by those warmer temperatures. But additionally, we also have atmospheric river events, which deposited substantial amounts of rain and snow in the Sierra Nevada last winter. And these are expected to intensify under a warming climate as well.

So even as the southwest region generally becomes drier, we're also likely to experience punctuated periods of more extreme precipitation. And this makes managing impacts of climate change on our water supplies really challenging. This is in part because our region's water infrastructure was designed to manage water resources that arrive as snow and melt slowly, not as floodwaters or even distributed rain, and updating this infrastructure is difficult and expensive.

Third, and finally, the impacts of climate change are already being felt across the Southwest, and they're often felt disproportionately by different groups of people in this region. So for instance, the Southwest is home to many indigenous communities. Some of whom lack access to potable water resources.

This injustice became particularly visible during the COVID-19 pandemic, which initially spread much more rapidly among Indigenous communities than non-Indigenous communities in the region, in large part due to this lack of clean water and sanitation services. In addition to facing financial burdens associated with developing this costly water infrastructure, some Indigenous communities continue to face legal barriers to obtaining or using their water rights.

Studies have also documented how other communities are overburdened when it comes to climate change. So, for example, Black communities in Los Angeles face disproportionately higher flood risk, and Hispanic and low wealth communities may receive lower water quality than their white and wealthier neighbors.

These overburdened communities may also be less likely, or even less able, to participate in water management processes that aim to counter climate impacts and promote adaptation and community resilience. Evidence of these disproportionate impacts suggests that we must pay close attention to all potential inequities when developing climate change actions in order to make our responses more just and sustainable for all communities in our region.

Sarah LeRoy: Great, thank you so much. I also wanted to ask, what do you find hopeful or encouraging from this key message? 

Elizabeth Koebele: Sure, so the last line of the Water Resources key message reads, flexible and adaptive approaches to water management have the potential to mitigate the impacts of these changes to our water resources on people, the environment, and the economy.

The chapter team only had medium confidence in this statement, but that's not because climate adaptation isn't happening. In fact, it's happening more broadly and rapidly than ever, especially around water in the Southwest. However, we don't necessarily know exactly which adaptation strategies are going to work the best for specific circumstances and locales, if there are unintended or inequitable consequences, and so forth.

And that's in large part because this is just the beginning of a long term effort to live with climate change in our region. And it may seem a little bit ironic for me to cite this aspect of our key message as being particularly hopeful or encouraging, but I really find it amazing that our chapter team was able to not just focus on the problems that climate change is creating for water in this region, but also the potential solutions that we're already seeing implemented to counter these impacts.

This section of the key message also highlights a critical role for the social sciences in building climate resilience. Even if we have the best technical solutions to climate change, we need to find the social and political will to implement them and ensure they help our diverse communities and economies be resilient.

So to go a bit more into detail, this section of the chapter particularly emphasizes that we've seen policy actors across various sectors in the Southwest begin to collaborate more closely than ever before to sustainably manage our water resources. So California's Sustainable Groundwater Management Act, which we call SGMA, is a good example.

As California's first ever major effort to manage groundwater, SGMA essentially creates local groups that work collaboratively to develop groundwater management plans in order to reverse aquifer decline. By devolving management of water resources to this local level, with state oversight, there's the potential to integrate new actors into the decision making process and to develop solutions that better fit unique contexts.

Of course, there is substantial variation in the groundwater management plans being produced and their projected effectiveness, which require continued evaluation and adjustment, especially as climatic conditions continue to evolve. Similarly, even though we discussed at length the dire situation that the Colorado River Basin is in, with reservoirs at their lowest levels ever in the past few years, We have also seen historic collaboration among states, the federal government, indigenous communities, Mexico, and even non-governmental and private organizations to develop solutions to water challenges in this basin.

We've also seen individual cities in the Southwest, such as Las Vegas, emerge as leaders in water conservation and share their innovative strategies with others throughout the region. So, once again, we still have a long way to go to make our water sustainable in the Southwest, but the fact that we have so many amazing examples to work from and to improve upon really gives me hope for the future.

Sarah LeRoy: Excellent. Thank you so much for joining us today. 

Elizabeth Koebele: Definitely. Thanks for having me. 

Sarah LeRoy: Lastly, we'll be talking with Dr. Mark Brunson about key messages related to agriculture and wildfire in the Southwest. Dr. Brunson is a professor in Environment and Society at Utah State University. His research focuses on rangeland ecology and management, translational ecology, and the intersections of social and environmental science.

Dr. Brunson served as an author on both the agriculture and wildfire key messages. Regarding agriculture, the overarching theme is that increasing challenges confront food and fiber production in the southwest. The overarching theme of the wildfire key message is that changes in wildfire patterns pose challenges for Southwest residents and ecosystems.

We'll focus on agriculture first. So Mark, thanks for joining us. I just wanted to start off asking, you know, what would you like people to know about the climate change and agriculture key message from the report? 

Mark Brunson: Well, first, thanks. Thanks for inviting me to speak with you. I, um, you know, this message sounds daunting.

Increasing challenges confront food and fiber production in the Southwest. And it's true, but we've met challenges before, and we can meet challenges again. So I think that's important to say at first, you know, what those challenges are. You know, we're quite certain that continued drought is going to pose a challenge, uh, there's going to be, you know, especially if there aren't major shifts in technology, you know, new things that we develop to be able to address these challenges, uh, for agriculture producers, new practices that may be tried.

And so, you know, you've already heard about water from Elizabeth and, you know, we know that this is going to be a problem. The other part of it, of course, or closely related is, is heat and warming and longer growing seasons are going to happen. And so that has some positive aspects, but it comes with some negatives as well.

So, for example, it means more heat stress to crops and to livestock. It could mean false spring events in particularly the more intermountain west kind of states in our region, thinking about, you know, parts of Nevada where there might be some agriculture, certainly in Utah and Colorado, where, you know, the plants begin to respond to what they think is spring and then we get a late winter storm event that causes a challenge.

So the heat is going to make a difference. I think California is an area of special concern. You know, think about it, you know, we, we tend to think of California, and we think about Los Angeles, and we think about the Bay Area, and we think of it as this hugely populated urban state, but it is also the state with the most agricultural income of any place in the country.

You know, it's really, really important for vegetable production, for nuts, and, and some other crops. And so wine, grapes, certainly. The facts, you know, the, the, the impacts on, on California crops is of, of considerable concern. We expect that production and also the quality of some products may be reduced.

That doesn't mean that they won't be edible. It doesn't mean we won't be able to get these products. But we may, you know, we may have to pay more for them. We may find that they're not as pretty as we thought they would be in the past. And there are economic costs to, to California, you know, of course, a state with so many millions of people.

You know, the 2021 drought alone cost over a thousand jobs and one and a quarter billion dollars, uh, to the agricultural industry. Uh, and that was just one summer. And so, you know, we, we really need to think about how to address those challenges. Something that I think we should all be really concerned about is, is the effects on food security.

When prices for food go up, some individuals are more likely to not be able to get the foods that they need. They may be forced to turn to processed products rather than produce or something like that. You know, I think about frontline communities such as agricultural workers, Hispanic populations, Native American populations, and you know, which are so important in parts of the Southwest.

You know, all of, all of these may be particularly vulnerable to it. Also, I think farmers and ranchers who are maybe first generation or women ranchers, you know, operations that are not as well tied in with the standard networks of irrigators or of producers, ones who may not be as tied into information sources about what they can do.

Those folks are going to be more vulnerable to these impacts. And, and finally, I think the big, the other challenge that I see is, is more of a human challenge. You know, we, we do know some solutions and they often involve things like changing, you know, being more efficient with water or shifting crops.

But it's difficult for farmers and ranchers to change very often. It's costly, you know, a study a number of years ago by New Mexico State University scientists said that ranching operations typically have about a two percent profit margin. And then when you have a bad year, you know, that profit is very, very quickly used up.

And so when we come along and we say at the same time, Oh, we'd really like you to, to make this change. Let's move to a heritage breed of cattle that's better adapted to the desert. You know, well, wait a second. I can't just make that change, you know, and, and also, you know, the, the policies that we have sometimes in, in, you know, over the built up over decades in terms of farm support programs, for example, may, may tend to discourage change.

And then finally, just distrust, uh, you know, we're at a time when, when experts are held in, in less esteem for better or for worse. And so all of those things can get in the way. So that's, those are the challenges that I see. On the hope side, I don't want to leave us there. You know, I want us, I, I honestly believe that we do a disservice when we make it sound too dire.

We are a species that has been enormously inventive. We have survived all kinds of things. And, and we're, we're learning. We, you know, the number of people who are doing climate science now and, and learning about what the impacts are, but what can be done about them. One of the things that I think is important is that more and more social scientists are looking at these challenges.

And so they're looking at things like governance, you know, how, how do we govern and direct the use of water? How, what kinds of, of laws and regulations and institutional mechanisms we might have. There's this thing called policy entrepreneurship, and we have more and more people who are really interested in the idea of let's try some new things.

Uh, very often in small regional areas, there are, there are pockets of innovation across our region where cool things are happening. Uh, I think at the bootheel of New Mexico and Southeast Arizona, where ranchers have been doing really interesting things. Uh, you know, efforts in the San Luis Valley of Colorado to look at new ways to think about water. You know, and of course in California, lots of things like that. 

So, I feel like new solutions are on the horizon. And yeah, we need people to adopt those solutions and we need to get past that trust barrier. But I've been studying rancher adoption of innovations for the last 20 years. And one of the things that I've found is that if just a few people try something and other influential people see what they're doing and say, Hey, that, that seems to be working. I'll try that too. You can cross this threshold and all of a sudden lots and lots of people are picking up new practices. So I'm not super concerned yet because some of the new things that are being tried aren't being adopted very well. 

And then the last thing that gives me hope is that I recognize that you know, the Southwest was one of the most heavily populated parts of the North American continent prior to the arrival of Columbus. You know, the people here, indigenous folks, learned how to adapt to the climate we have here. And we're in a place now, as a society, where we're starting to listen to those kinds of things again. We're not simply, you know, sitting, oh, that's, that's just primitive knowledge, you know, and we know all the science.

People are really interested in, in traditional ecological knowledge and indigenous knowledge. And I, I really see that there are lessons to be learned from adaptations that occurred, you know, 600 years ago or 300 years ago. And so, you know, we're, we're listening more to that. And so all of those things give me hope.

Sarah LeRoy: Great. Thanks so much, Mark. So let's switch now over to the wildfire key message. And so what would you like people to know about, about that key message? 

Mark Brunson: Short answer for that message was changes in wildfire patterns pose challenges for residents and for ecosystems. And I think one of the things that I really want to highlight there is changes in wildfire patterns.

So fires have been burning in our region for millennia. Lightning storms have happened. Native people were using fire long before European settlers were in this region. And so what's changing is not so much that there's fire, but the way it burns, when it burns, how hot it burns, how large our fires are, and so I think that's that's an important thing to know.

Something that there's been a fair amount of debate about what's causing increases in wildfires, especially in California, but not only there, and you hear these people talking about how, oh, well, you know, it's all about bad forest management, or it's all about climate change. And, and that's a false dichotomy.

It's not an either or, it's an all of the above. We know that fire suppression policies in this country enacted, well, especially after the 1910 very large wildfires in the Northwest, and in that time, and then even more so after the Second World War, when timber became, timber from National Forests became really popular. We've been putting out wildfires when we should have been letting some of them burn. 

You know, and I think about here in our region, for example, the ponderosa pine forests that are are common in California in fact, there's even ponderosa pine forests in Nevada, but all of the states have this forest type which is adapted to fire and yet we put them out and when we did so we allowed more undergrowth to grow in those places.

And so now when the fires do catch the trees are not adapted to the intensity of the fire and the the amount of fuel that is being consumed by a fire. So fire suppression is a problem and and that fuel buildup is something that we're going to need to address. We know that fires are getting more likely to burn hot because we have a drier and warmer climate.

There's a really good podcast in the Come Rain or Shine series back in August that featured three scientists from California who talked about what the research there has shown, and for the most part, that applies across all six states of our region. And so I won't, you know, if people really want to dig deeper, I encourage you to go listen to that podcast.

But one of the challenges we have, though, is that most of the research has been done in that state. And yet, it's a, it's a problem across our region. The largest wildfire in all six of our states, and at least the largest wildfire recorded, has occurred since 2007. Fires are getting bigger. In California, they're not, we're not getting more of them, they're just bigger.

But in other states, in the Great Basin, we are actually getting more wildfires. That's partly because of climate change and partly because so many more people live in the region. But, but so, so climate change is certainly part of the challenge. And then, and then also to some extent, especially again in California, but also probably in other states, we stopped indigenous burning practices that help to reduce the impacts of wildfire.

And so, so all of those things are happening. Our region has suffered the greatest amount of property loss and property costs. Partly that's because of where we build our homes. We like living, especially in a hot region, you know, we like living in the shade. Right. And so we do that and then we find ourselves living among trees that are quite flammable.

We've seen changes where some places that have been forest aren't going to be forest anymore. They're becoming woodlands. And so that’s distressing to people, especially if they've come to love a particular landscape. It doesn't mean that these other kinds of, of vegetation types aren't important, they're just different.

But we're going to have to adapt to that to some extent. And we're going to have to figure out how to deal with smoke. Smoke is such a challenge and, and I expect, you know, few people have heard about the cost to health, you know, the smoke has led to, like during COVID, an increased COVID related hospitalizations because, because the smoke was adding to the respiratory distress.

It costs agriculture, and so these various aspects that we've been talking about through throughout this session are all related in some ways. And so, so I think, you know, we're going to, we're going to need to be able to address those things. But again, when I come to the part about are there things that give me hope, I think we have that capacity and we're starting to do it.

Adaptation to wildfire can be costly. It means that some people may not be able to build where they wanted to. It means they may find it difficult to get insurance. It means that they need to spend more on building practices that reduce the likelihood of a fire. But we're, we know how to do these things.

We're learning how to, to build more fireproof homes. We're learning how to figure out where a fire is most likely to burn and maybe say that's not the best place to build, maybe you should build over here. Some of these things are really like ways to close off vents in your house that where embers can get into the home, you know, those are becoming more and more available and easy to install.

So there's, there's things like that, and we're seeing people accepting that this is the world we live in. This is, we are in a more flammable landscape and a more flammable world, and we need to reduce the things we're doing as a society that make the climate change, but we're also going to have to adapt.

And again, as I said before with agriculture, we need to be turning to the wisdom of people who were living here long before we were. You know, indigenous burning practices are starting to be picked up again. We are learning from the past. We are using more prescribed fire under circumstances where it's likely to have less negative impacts on people. We will make mistakes because we are human, because we can never know everything, but we are, we're headed in the right direction. And I'm just so excited to be part of, of looking for those solutions. 

Sarah LeRoy: Excellent. Thanks so much, Mark, and for ending on that very hopeful note. And I just also wanted to thank Dr.Vanos and Dr. Koebele for speaking with us earlier. And for our listeners, the entire National Climate Assessment, including the Southwest Chapter, can be found online. The link is shared in the episode notes. So thank you once again, Dr. Brunson, for joining us. 

Mark Brunson: You're very welcome. It was a pleasure.

Thanks for listening to Come Rain or Shine, USDA Southwest Climate Hub and the USGS Southwest CASC. If you liked this podcast, don't forget to rate or review it and subscribe for more great episodes. A special thanks to our production crew, Skye Aney and Reanna Burnett. If you want more information, have any questions for the speakers, or would like to offer feedback, please reach out to us via our websites.