Pollinators in a Changing Climate: Threats and Solutions

We’ve all heard about climate change. It’s a rather complicated issue. One that has come up several times in this podcast as we discuss the threats facing invertebrates. So in this episode, we will focus on what we can expect as our climate changes and what that means for our pollinators. And of course, what actions you can take to help these important insects in the face of climate change.

Joining us to talk about this issue is Angela Laws, Xerces Society Endangered Species Conservation Biologist and Climate Change Lead. Her role at the Xerces Society involves incorporating climate resiliency into pollinator restoration projects. Angela has over 15 years of experience studying arthropods in grassland habitats, including studies of how climate change can affect species interactions.

Thank you for listening! For more information go to xerces.org/bugbanter.

Transcript

Rachel: Welcome to Bug Banter with the Xerces Society where we explore the world of invertebrates and discover how to help these extraordinary animals. If you want to support our work go to xerces.org/give.

Rachel: Hi, I'm Rachel Dunham in Missoula, Montana.

Matthew: I'm Matthew Shepherd in Portland, Oregon.

Rachel: We’ve all heard about climate change. It’s a rather complicated issue. One that has come up several times in this podcast as we discuss the threats facing invertebrates. So in this episode, we will focus on what we can expect as our climate changes and what that means for our pollinators. And of course, what actions you can take to help these important insects in the face of climate change.

Rachel: Joining us today to talk about this issue is Angela Laws, Xerces Society endangered species conservation biologist and climate change lead. Her role at the Xerces Society involves incorporating climate resiliency into pollinator restoration projects. Angela has over 15 years of experience studying arthropods in grassland habitats, including studies of how climate change can affect species interactions.

Rachel: Welcome, Angela. We're so excited to have you here today.

Angela: Hi, thank you for having me and happy to be here.

Matthew: Great. To start with, can you give us an overview of what's happening to our climate and why?

Angela: Yes, so greenhouse gases occur naturally in the atmosphere and they form this insulating layer around the planet. And what's happened is since the Industrial Revolution, as we've been burning fossil fuels and emitting more and more of these greenhouse gases, we've increased the amount of these greenhouse gases in the atmosphere. 

Angela: Sort of increasing the—this insulating layer, right? So it's like in winter when you swap out a cotton blanket for a down comforter, that's sort of what we're doing to our planet. And as a result, we’re seeing more warming. So each of the last five decades have been warmer than the ones before. The 10 most recent years are the warmest years on record. And so this warming has caused lots of different effects to our climate.

Angela: We're seeing more heat waves, more intense heat waves. We're getting more drought. We're also seeing an increase in extreme weather events. We're seeing sea level rise, so our sea levels have increased 4 inches since the early nineties.

Angela: We're getting ocean acidification. All of these different impacts. And I think something that probably a lot of our listeners have noticed is that climate change is no longer something that's going to happen to us in the future.  It's here now. It's happening now. We're seeing these impacts on human health, on our economy, agriculture, but also on biodiversity. And so we can no longer afford to continue to look away from this problem.

Matthew: Sure. You know, just in the news today, there's like extreme rainfall in Florida and flooding where like city buses can't get through and, so yeah.

Matthew: We, we really are beginning to see that—see the impacts of this. You've used a few times, you know, you talked about greenhouse gases and global warming and I know that there are lots of different terms that get used to describe this, global warming, green house effect, climate change. Are they all the same? Or are there differences and what would be the most appropriate term if we need to just have one?

Angela: Yeah, so the greenhouse effect is sort of the process that explains how climate change is happening. It's how these greenhouse gases form in this insulating layer. That's the greenhouse effect. Global warming and climate change can be used interchangeably.

Angela: More technically, global warming could refer to just the increases in temperature, while climate change can encompass all of those other changes like sea level rise, ocean acidification, changes in humidity and extreme weather events. So I feel like climate change is maybe more accurate than global warming. But I think a lot of people use those two interchangeably.

Matthew: Yeah. I also know there's a kind of a lot of misconceptions. We've all heard it being said. Oh, we've got a cold winter so we don't need to worry. But a lot of that is probably weather rather than climate. I mean, could you try and explain what the difference is between weather and climate?

Angela: Yeah, so weather is what's happening in a specific place at a specific time. So I'm here in Sacramento. A few days ago it was—we had a high of 100 degrees and today the high is only 87 degrees, so that's the weather.

Angela: Whereas climate is our long term average of weather. So, averaging what's happening over scales of decades or longer. That's climate. And so we're seeing changes in these average temperatures. And so that's the difference, you know, with weather or with winter, we're still going to have winter. 

Angela: It's still going to be a thing, even with climate change. It's just that our seasons are going to look different. They're going to look warmer. Sometimes they're going to get colder. As I said, we're going to have more of these extreme weather events.

Angela: We're hearing more about polar vortexes now, right? And atmospheric rivers. And some places are going to get a little colder, but a lot of places are going to get warmer.

Rachel: So since we're talking about pollinators specifically, in general, and not hypothetically, because we're seeing some of these impacts, but what are the aspects of climate change that could directly impact these insects?

Angela: So there are many ways that climate change can impact pollinators and other insects. One of the ones that we hear a lot about are the potential for these phenological mismatches between pollinators and their plants. So phonology is a fancy word for the timing of biological events like the timing of when bees emerge in spring. And many bees have evolved to emerge when the plants that they take pollen from are flowering. 

Angela: But if the pollinators and their plants are responding to different cues—so for example, maybe pollinators are timing their emergence based on temperature and the plants are timing flowering based on day length—those timings can get offset and you can get a mismatch so that the pollinators are no longer emerging when they're plants are in flower, which can have negative impacts on the pollinators and the plants that rely on them.

Angela: There are other types of potential impacts. Insects are really sensitive to temperature. It affects so many biological processes. It affects how large they are as adults, how many offspring they produce, when they can be active each day, how many nutrients they absorb during digestion.

Angela: And so changes in temperature can be really important. Small changes can sometimes be beneficial, but if it gets so hot that the animal is bumping up to that upper limit—that upper temperature limit that they can tolerate, then it can start to have negative impacts on their behavior or reproduction or survival.

Angela: Plants are also responding to climate change and that can impact pollinators. For example, in California, we're going to get more drought. And so that will mean fewer resources for pollinators on the landscape. There's some cool studies showing that for some plants, the attractiveness of the flowers can be influenced by temperature and by carbon dioxide concentrations. It can also affect the nutritional quality of pollen and nectar.

Angela: There's things like that. So many different impacts. Species range shifts can respond to climate change. Species interactions can shift. And then of course, all of these effects can interact with other drivers of biodiversity loss, right? And pollinators are being impacted by pesticide use and habitat loss and pollution and disease. These other drivers of biodiversity decline can interact with climate change and potentially exacerbate negative impacts of climate change on pollinators.

Rachel: Yeah, that makes sense. I just imagine like that frustration when you go to the grocery store and you need to get something and it's closed. It's like a bee coming out and being like, wait a second, where's my floral resources? Like there is no option B for them, right? I mean, they're just sort of stuck.

Rachel: And then they have these other stressors of like, oh, I'm really hot and I have just been—my nest was sprayed with pesticides and these other things that are affecting them.

Angela: Right. Right, yeah, you can imagine that exposure to some pesticide during a heat wave or during drought may be more problematic than during, you know, more optimal conditions for the pollinator.

Rachel: Yeah, definitely. Are there any ways that pollinators are being positively affected?

Angela: So there will be winners and losers. Some pollinators will do well under future climate scenarios. We talked about how plants are responding to climate change. Some plants will do better and if a particular pollinator is a specialist on that plant or maybe a butterfly that uses that plant as a host plant, potentially if that plant becomes more abundant, that pollinator may also become more abundant.

Angela: So some species will do okay. Some species will be able to adapt to new climbing climate conditions. But there's also a lot of studies showing that climate change can cause biodiversity loss and the magnitude of biodiversity loss that we're expecting is correlated to the magnitude of climate change. 

Angela: Which is bad news, but the flip side of it means that the sooner we act, the sooner we can reduce carbon emissions to zero, the more biodiversity we can protect.

Rachel: This might seem like a basic question, but I think for people who may not have, you know, an ecology background or fully understand why biodiversity is important—because even if we have winners, we still have a lot of losers. So we're decreasing the diversity.

Rachel: So why is biodiversity even important? Like why do we care that we have only 10 species of bees instead of a hundred? Like we still have those 10, right? That's great.

Angela: Right. Yeah. That's a great question. I think that there are a lot of reasons to care about biodiversity. There are a lot of like ethical and moral reasons to care. But if you want to look at it just from the standpoint of what do we get out of it, biodiversity and ecosystems provide us with all of these ecosystem services. All of the things that ecosystems do that make life on this planet possible and even pleasant. 

Angela: Things like pollination, carbon sequestration, water filtration, decomposition, nutrient cycling, we need these things to happen. And what we find over and over again is that biodiverse ecosystems, ecosystems with lots of species, are better at consistently providing these services over time than ecosystems with poor service. With poor biodiversity. And that applies to carbon sequestration too.

Angela: So there's these cool studies happening at Cedar Creek, which is one of the long term ecological research sites. And they have these patches of grassland with different numbers of species in them. And then they're looking at carbon sequestration. And what they find is that grassland patches with lots of species in it are better at consistently sequestering lots of carbon than the patches with only a few species of plants.

Angela: So high biodiversity helps maintain those ecosystem services that we rely on. And the same thing with pollinators. Having many species of pollinators means we can more consistently get those pollination services that we need, you know, during cold snaps and heat waves and extreme weather events.

Angela: And so that's why biodiversity is important. And I'm glad you brought this up because when I talk about climate change, one of the things I really like to talk about is how climate change and biodiversity are linked. We have to address climate change if we want to protect biodiversity. But on the other side, we need biodiversity to help us adapt to and mitigate climate change.

Rachel: Thank you.

Matthew: I was going to ask you about evidence to support some of the things you said and you’ve hinted at that, you know, you mentioned the LTDR, grassland plots, etcetera. And I know that there are some people who were pushing back against the idea that climate change is happening and they're always saying, but look at this, look at that. And then you also read how—is it 97% of published studies support climate change being a real thing? 

Angela: Yes.

Matthew: And so, I mean, I know we're talking mostly about pollinators, but presumably there are studies that have been done that illustrate these impacts and these changes that you'll be talking about

Angela: Yeah, yeah, 97% of climate scientists agree that climate change is happening and that it's caused by human activities. And we're seeing the impacts become more and more apparent. There was a study a few years ago looking at western butterfly abundances and they found that western butterflies have been declining at a rate of 1.6% per year over the last 40 years and those declines were most strongly linked to increases in fall temperatures. So here we're seeing the fingerprints of climate change on biodiversity decline.

Angela: But then there's also other studies just looking at, for example, plant-pollinator interactions. So a study that came out just a year or two ago out of Argentina. Diego Vasquez and his colleagues looked at phonology of emergence in flowering plants over nine years for five species of bees, and they found that the negative impacts on those bees were stronger when there was a mismatch.

Angela: So these mismatches were leading to decreases in reproduction, decreases in population growth, and the effects were stronger for specialist bees than for generalist bees. Which makes sense because specialist bees are using a narrow subset of plants. Whereas generals can use lots of different plants. So if their flowers aren't blooming, they can use something else, whereas the specialists can't.

Matthew: I was also thinking about—I mean, I've read some of the studies that have come from Rocky Mountain Biological Lab looking at bumble bees and lupines and the shifting there. And also I'm thinking of the Uncompahgre fritillary is one example of a montane and alpine butterfly whose habitat is shrinking, very much reliant upon, you know, it's that snow willow that grows just underneath that permanent snow patch and, you know, there are no snow—permanent snow patches are melting away.

Angela: Yeah, and with those montane species, I feel like the trap is that we get these warm springs. So it starts getting warmer earlier, pollinators come out and then maybe they get the snow again or a cold snap after the bee has emerged and that can be really detrimental to pollinators as well.

Matthew: Yeah, I notice that even down here in the lowlands where I live in Western Oregon. We don't get a lot of snow right in Portland, but recently we've been having the warming in January early February, you know, and then bumble bees will start emerging. And then we'd have a week or more of freezing and I mean we got down into the teens this year which is almost unheard of in our area. And you're like, oh, those poor bumble bees.

Angela: Yeah, the weather is weirder. I think that's a term that Katharine Hayhoe uses. She's a climate scientist that talks about global weirding. The weather it's just stranger as a result of climate change.

Matthew: Yeah, I, I think we're all noticing that one way or another. Yeah.

Rachel: I think climate change can feel—it is a really big issue and it feels unmanageable as just one human being. Like, what am I going to do to make an impact on climate change? I'm just one person, right? But at Xerces, we are all about finding solutions, through both big and really small actions that really do matter and have an impact.

Rachel: So I kind of want to look at maybe different groups of people. So let's start with gardeners. I know lots of gardeners follow Xerces. They are our members, our donors, folks that are listening to the podcast right now. What can they do to help combat climate change for pollinators in their yard and in their communities?

Angela: Yeah, I think it starts with creating habitat. Species need a place to live in order to persist. And so the more habitat we can create, the larger populations can be, and in general a larger population is less vulnerable to extinction than a small population. So I think it starts with creating habitat, planting flowers. Planning a diverse assemblage of flowers to support a diverse assemblage of pollinators is important.

Angela: And I think that I think it can feel small. Like, I'm in my garden, I'm planning this plant, how big of a difference could it make? But it's not up to you to support all the pollinators in your neighborhood by yourself because there are other people gardening and other patches of habitat. 

Angela: So each garden that we add kind of increases the total amount of habitat on the landscape, it increases connectivity and that can also reduce extinction risk in general for pollinators. And so I think that's really important. I do think that we can make a meaningful difference and increase climate resiliency for pollinators by creating habitat. It can increase biodiversity, but also increases carbon sequestration services.

Angela: I think in particular, planting native trees. Native trees support hundreds of species of moths and butterflies, but they're also really good at carbon sequestration, right? Trees are like giant sponges that are just soaking up carbon dioxide from the atmosphere and converting it into wood and other tissues that are stored for decades, or longer. So it has that benefit. It also—planting trees in parts of the country where it's appropriate is really great for addressing the urban heat island effect. 

Angela: So our cities and towns are warmer than this surrounding landscape because of all the concrete and asphalt. And there are studies showing that if we have a healthy urban forest, we have lots of trees, that that can minimize that urban heat island effect, especially during heat waves. So it can keep the temperature from getting too hot during those heat waves, which is good for people and also good for our pollinators.

Angela: And then finally, the other thing that I think is important. We talked about how other drivers of biodiversity decline can interact with climate change. And so that's why I think it's important to address those where we can, particularly by avoiding the use of insecticides and other pesticides around our communities or at our homes in these habitats. Because that's just like one more stressor that these pollinators have to deal with and we can—if we remove that—we can help them be a little bit more resilient to climate change.

Rachel: I know you had previously provided me some slides for a presentation I did, and it was really interesting to look at like the heat maps of particular cities and just how concrete really does impact heat. And you can feel it on a hot day if you change surfaces of where you're walking. 

Rachel: But you has also mentioned just different types of plants based on how the weather is changing. Sort of like thinking ahead of like, if we're going to have more drought, get drought tolerant plants. Or if you're having mass floods, like, you know, get plants that can handle a lot of water.

Angela: Yeah, right, looking at climate projections can help. I think that aiming for biodiversity is a good way to go. There are parts of the country where unfortunately they are going to get more droughts and more floods and it's hard to find plants that are good at both of that, but if we have a—if we aim for biodiversity, if we have many species of plants, then we're likely to always have some species that are in flower each year and providing nectar and pollen for our pollinator friends.

Rachel: Yeah, that makes sense. Increasing resiliency, just making it stronger.

Matthew: I know we're talking about, habitat, and carbon sequestration and stuff, but I also think that something else that gardeners can do is inside their house, which is to adjust their thermostat. Because, you know, that's another way in which you can—a small contribution. Maybe, you know, do you need your air conditioning to kick in quite where it does? Do you need that heat at that level? I mean just a degree or two down in your heat or degree or two up before your A/C kicks in, really can make an impact as well. And it saves you dollars in your pocket. So. Win win, right?

Angela: Yeah, I think there are some great ways to reduce our carbon footprints, like trying to reduce food waste, for example, taking public transportation, if you—if we can. Though I think that ultimately we also need top-down solutions. And I like to suggest people maybe decide once a month you're going to contacts one or two of your elected leaders and call them and tell them you want them to act on climate change because I do think those phone calls have an impact and I think they need to hear from us. So that's I think a positive action that you can take. It's a pain, but I think it's worthwhile.

Matthew: Yeah. Be the squeaky wheel, huh?

Angela: Yeah, yeah, be annoying. Nothing else.

Rachel: Yeah. So we talked about gardeners. What are things that public land managers can do?

Angela: I think it's similar. Similar types of things. At Xerces our approach is to protect habitat where we can, create habitat where we can, increasing habitat connectivity, and then reducing those other stressors. So for public land managers, I think it's just about restoring habitat, trying to control invasive species and weed—noxious weeds. 

Angela: Making sure—you know, you can think about imperiled species. What are, what are the declining and vulnerable species that occur in your area? Are you including the host plants for those species and the pollen and nectar plants that those species need in your restoration plans? Like thinking about which of the species that are most likely to be harmed and trying to proactively make sure that they have the resources that they need.  Not just food plants but also nesting and overwintering habitat.

Rachel: And what about farmers and ranchers?

Angela: So I think that the agricultural community has a real opportunity to have the capacity to really contribute to climate mitigation, or to mitigating climate change. Actions that they can take to improve soil health helps carbon sequestration. Farmers and ranchers that create habitat on their property, usually that increases carbon sequestration while also supporting pollinators that are beneficial to the producers as well.

Angela: Any sustainable farming practices can potentially contribute to addressing climate change while also supporting pollinators.

Mathew: Yeah. There are just so many things that people in different places can do. So, but now, as you say, we definitely need politicians. We need the top to be acting too, but it's also nice that as individuals we can take a little bit of control.

Angela: For sure. No, I think it's definitely worthwhile and I do think that creating habitat and reducing our carbon footprints where we can is definitely worthwhile and it's meaningful. And the nice thing is when you do something like creating habitat, the pollinators show up almost immediately. Like you get that instant response, which is really fun to watch. Yeah.

Matthew:  Yeah. And the sooner we do it, the more we can admire it and, maybe we'll get on top of this problem, huh?

Angela: That's right. We'll get more people invested.

Matthew: Yeah. I mean, as Rachel said earlier, this seems like this is a huge issue and it's like weighing down on us. But there are stories of hope as well. I mean, there are individuals, communities who are making an impact, who are taking these steps.

Angela: Yes. There was a report out just recently describing that there are seven countries that now generate 99% of their energy from renewable sources and these are spread out all around the world. And then there are also a few countries that are able to get a hundred percent of their energy from renewals for short periods of time. And this makes me hopeful because it demonstrates that we have the technology. We have the technology now. We're not waiting for some miracle new tech to come out and save us. We have it. We just need the political will. And so that gives me hope. 

Angela: At Xerces, part of my job is running our habitat kit program with my coworker Jessa and we give climate smart, drought tolerant plants away to people creating pollinator habitat across California. And that project inspires me because there are so many people who care, who are out there giving up their time and energy to create habitats. So they're supporting pollinators, they're supporting biodiversity, they're increasing carbon sequestration services where they're planting. And that to me is really inspiring. Over the last five years, we've had more than 500 projects planted in California through this program. And that makes me hopeful.

Matthew: Yeah, no, that really is lovely to hear. And being in conservation we're confronted with all sorts of things that seem bad and terrible, but knowing that there are people doing that is great. And I know that over the years, certainly for me, the people I interact with, who I can see, their hearts are in the right place and they're doing things—really is an inspiration and something that kind of keeps me going sometimes when everything else seems gloomy. Yeah, lovely.

Angela: Yeah, I think it's important. I certainly have had more than my share of sleepless nights. I recently read a book called The New Climate War by Michael Mann, who is a climate scientist. And he talks about how the people who were responsible for climate denialism have shifted tactics to spreading climate doom. They want us to feel despair. They want us to feel hopeless because then we give up. And then the status quo is maintained and they continue to make lots of money. Like obscene amounts of money. And so I think it's natural to feel—have these moments of despair, but we can't give into that. We have to find these things to feel hopeful for and to continue to act and to fight to reduce carbon emissions. Every little bit helps.

Matthew: Yeah, definitely.

Rachel: I think it makes me emotional thinking about future generations. I don't have kids, but it inspired me as a kid, like all the wildlife I saw and the different animals. That's why I'm doing what I'm doing and I just can't imagine years and years down the road, you know, next generations not experiencing that because these animals have gone extinct or because our world can't sustain this biodiversity.

Rachel: And I just think we should do what we can. It's incredible to see the people out there that really are taking action and even if it feels small, it's a lot bigger than you think it is.

Rachel: So are there any particular resources that you can recommend for people for more information if they want to take a deeper dive into climate change.

Angela: Yeah, I love NASA's climate change website. They have a lot of great information and a lot of really cool interactive maps and graphics. So if you want data and facts, I like NASA. 

Angela: I mentioned Katharine Hayhao. She's a climate scientist and a really great communicator. She has a great website. It's katharinehayhoe.com and she has a ton of resources there—informational videos, links to organizations that you can join. So there's just a lot of information there and a lot of it is really accessible and easily digestible. So I am a fan of that. She has a new Instagram account, @talking_climate, and it has posts with some not-so-good news but also good news and actions that people are taking and I think that that's good, you know, to feel like you can do something—that there's something we can do about this problem. And I find that inspiring. I like her work. 

Matthew: Other resources we should recommend are from xerces.org. Go to our website to find all those plant lists and information about how to create that perfect patch of habitat wherever you are.

Angela: Exactly. Yeah, we have tons of information. We have a few fact sheets about creating climate-smart habitat for pollinators in different environments. Those are geared towards California, but I think a lot of that information is applicable to other parts of the country as well.

Matthew: Yeah, definitely. A lot of times it's the principles, you know, swap in Michigan for California or whatever. And then it seems relevant.

Matthew: Angela, we're coming to the end. Thank you so much for this great conversation. Really, I mean depressing at times, but also up uplifting and funny. When I was telling people, oh, we doing a Bug Banter today and it's about climate change, and so if at the end I seem a little gloomy—but I am coming out actually feeling pretty optimistic and helpful because I can see some great stuff going on.

Matthew: We've come to our last question, which is also—Rachel, it's one of our favorites, which is what inspired you to work with insects? And associated with that. how did that lead to a focus on climate change?

Angela: Yeah, so I always wanted to be a scientist since I was a little kid. And we went camping all the time. I got to spend a lot of time outside and that's sort of how I came to ecology. As an undergrad, I got to do some research with grasshoppers and I was hooked—like insects are awesome.

Angela: I had no idea how much I loved insects until I started working with them. And then for—so for my PhD research and for my postdoc, I was doing research trying to understand how temperature can affect predator-prey interactions between grasshoppers and wolf spiders. And it turns out that even small changes in temperature can affect the way those interactions play out. It affects the grasshopper behavior and their survival. And that in turn impacts how grasshoppers are affecting vegetation in these grassland communities. 

Angela: And I got to do my postdoc research at Konza Prairie, which is one of my favorite places on the planet. If you're ever driving through Kansas, you should definitely stop and take a hike on the Konza.  So I loved that. I loved my research, but ultimately, I got a little burned out on academia. I wanted to do more hands on conservation work. And that's what led me to Xerces and my work with pollinators and climate change.

Rachel: I love though a lot of these stories that—when we ask people what inspired them a lot of them started when they were kids and just having exposure, but then the actual experience of seeing an animal in the wild like a grasshopper and learning more about them. So it just reinforces, like, get your kids outside. Get your grandkids outside. Get your friends' kids outside.

Rachel: Well, thank you so much, Angela. I learned a lot and I appreciate you talking about this difficult issue and subject, but I actually feel quite hopeful now. I think because I know that, you know, you're on it.

Rachel: You've got this. But yeah, thank you and I hope maybe we'll have you come back and talk about spider and grasshopper interactions.

Angela: Okay. Well, thanks for having me. It was a lot of fun.

Matthew: Bug Banter is brought to you by the Xerces Society, a donor-supported nonprofit that is working to protect insects and other invertebrates—the life that sustains us. 

Matthew: If you’re already a donor, thank you so much. If you want to support our work go to xerces.org/donate. For information about this podcast and show notes go to xerces.org/bugbanter.