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Not Cool Ep 12: Kris Ebi on climate change, human health, and social stability

October 8, 2019


We know that climate change has serious implications for human health, including the spread of vector-borne disease and the global increase of malnutrition. What we don’t yet know is how expansive these health issues could become or how these problems will impact social stability. On episode 12 of Not Cool, Ariel is joined by Kris Ebi, professor at the University of Washington and founding director of its Center for Health and the Global Environment. Kris explains how increased CO2 affects crop quality, why malnutrition might alter patterns of human migration, and what we can do to reduce our vulnerability to these impacts. She also discusses changing weather patterns, the expanding geographic range of disease-carrying insects, and more.

Topics discussed include:

  • Human health and social stability
  • Climate related malnutrition
  • Knowns and unknowns
  • Extreme events and changing weather patterns
  • Vulnerability and exposure
  • Steps to reduce vulnerability
  • Vector-borne disease
  • Endemic vs. epidemic malaria
  • Effects of increased CO2 on crop quality
  • Actions individuals can take

References discussed include:

At the core vulnerability just means the possibility of being harmed. It is an issue with climate change, because of course we're all exposed. We don't have some group that's not going to be exposed to climate change.

~ Kris Ebi


Ariel Conn: When talking about the threat of climate change, we often hear about how the poorest and most vulnerable communities will be hardest hit. Which is a problem we must address, but climate change will affect all of us. So what are some ways that you could be impacted? Hi everyone, I’m Ariel Conn and I’m back with episode 12 of Not Cool, a climate podcast. On this episode, I’ll be talking with Kristie Ebi about the toll climate change is expected to take on all populations. From higher risk of disease exposure to decreased nutrients in our food, all of us, no matter where we live, will experience the negative effects of climate change. 

Kris has been conducting research and practice on the health risks of climate variability and change for over twenty years. Her research focuses on the impacts of and adaptation to climate variability and change, including on extreme events, thermal stress, foodborne safety and security, and vectorborne diseases. She focuses on understanding sources of vulnerability, estimating current and future health risks of climate change, and designing adaptation policies and measures to reduce the risks of climate change in multi-stressor environments. She has supported multiple countries in assessing their vulnerability and implementing adaptation measures. She has edited four books on aspects of climate change and has more than 180 publications.

 Kris, thank you so much for joining us.

Kris Ebi: My pleasure.

Ariel Conn: So you fairly recently were an author on a paper called Climate Change, Human Health, and Social Stability: Addressing Interlinkages, and there's a lot of really interesting content in the paper, but one of the things that I thought was most interesting, it sort of helped really hit home with me, is — maybe you'll disagree with this — but just sort of how broad our unknowns are that we're trying to plan for. For example, there's a table in here where you talk about the social stability consequences of climate related malnutrition, and two of the questions that would be helpful to answer are, "Will malnutrition increase out migration, because people need better, healthier food? Or will it actually decrease out migration because people are basically too sick and too poor to be able to deal with trying to travel places?" And so I was hoping you could maybe start with: how much of an unknown do you think the future is, as we're looking at how climate change will impact us?

Kris Ebi: That's a really good question. There is, of course, lots of uncertainties about the future. We have uncertainties about the rate, for example, of climate change. The Intergovernmental Panel on Climate Change Special Report on Warming of 1.5 said that under current greenhouse gas emissions, the earth could warm an additional half degree over what it's warmed already from preindustrial times. The earth has warmed one degree Celsius, and the projections for 1.5 degrees Celsius indicate that the global mean temperature could reach that sometime between 2030 and 2052. So we do have lots of uncertainty about how quickly the climate system is going to respond to the additional greenhouse gases that are put into the atmosphere. We also have lots of uncertainties about then what happens with human and natural systems. How are they going to respond to the additional warming? We have uncertainties around how extreme extreme events will become. We know, for example, that heat waves are increasing in frequency, intensity, and duration.

We don't know exactly how fast; We do know we need to prepare. And the paper you referenced then pointed out there's lots of uncertainties around the human health and wellbeing aspects of these questions. How well the human systems respond, what kinds of choices will our governments make, and will we be prepared to handle the changes that are coming our way? So on the one hand, we do have lots of uncertainties. On the other hand, we also have lots of knowns. The climate is changing. Extreme events, as I mentioned, are becoming more intense; We know that many, such as heat waves, are becoming more frequent, lasting longer. So we have lots of information to use to better understand what the future could look like and how to start changing our policies and our programs to take those uncertainties into account, to be better prepared no matter what the climate change result is, and to reinforce our development patterns so that we move more towards a sustainable development pathway than the pathway that we're on now.

Ariel Conn: And so how do we get onto a different path, or what path should we be trying to get onto? How do we take what we know and address it?

Kris Ebi: The United Nations has an Agenda 2030 with sustainable development goals in multiple domains: human health, ecosystems, oceans, pollution. So that effort resulted in a series of goals and targets on moving to more sustainable pathways. How we can get there has been laid out by the United Nations and by other organizations as well, so we do have a sense of what it is we need to do. We do have a sense of the timing we have available to us to make the shifts that need to be made. And more importantly, when you look out at what's going on around the world, you see enormous transition taking place now — that countries, communities, individuals are making changes to move towards a more sustainable pathway, and it's helping facilitate those changes.

Helping people understand what kinds of changes, for example, at the individual level would be beneficial, to what kind of changes do you need at the community, the national, and the international level. So there's less unknowns than people like to emphasize. We do have lots of information and we do have lots of change underway. It's always good to remember that the future is not a total disconnect from today. There's a continuum between today and the future, and the future is already started.

Ariel Conn: We'll link to some of the information about the UN 2030 program. Does that lay out some of the different steps that we need to be taking at individual, versus community, versus national levels? Or are there places you recommend people go for more information?

Kris Ebi: To look internationally, I would recommend looking at Agenda 2030. It's quite detailed. There are 17 sustainable development goals, and under that are almost 200 targets, and under each target is a way to try and achieve that target. One of the challenges with the sustainable development goals is they're laid out individually: Here are the goals and the targets for health, and the ones for ecosystems, the ones for agriculture, the ones for water. The interconnections across those — the synergies and the trade offs — are not always articulated, so work does need to be done to make sure that actions taken in one sector will support actions taken in another sector so that we do ensure that as we move towards sustainable development, we reinforce across all the sectors the kinds of actions that need to be taken.

Ariel Conn: I want to step back to some of the risks that you've looked at. Your bio, I think, nicely sums up some of what I want to talk about. I'd like to start, I think, with just this definition of vulnerability. We hear a lot about places being more vulnerable than other sections of the world — countries, communities being more vulnerable than others — and I think there's sort of a vague sense of what that means, but I wonder if there's a more specific definition that's associated with the term.

Kris Ebi: There are hundreds of definitions. And when you look across all these definitions, at the core vulnerability just means the possibility of being harmed: that either individuals are vulnerable because they're more at risk for some adverse health outcome, a community is more vulnerable because of its location, or more vulnerable because most of the population is poor. There's lots of different ways that you can measure vulnerability. It is an issue with climate change, because of course we're all exposed. We don't have some group that's not going to be exposed to climate change. And in looking at how to allocate resources available for adaptation, for example, there is an effort to try and put those resources into places that have higher risks, where we're deeply concerned.

I do a lot of work in the Pacific. Low-lying island states are very concerned about sea level rise, storm surge, and what that means. People who live in the middle of the US, where there's been a series of droughts and floods, are much more concerned about droughts and floods, obviously, than sea level rise. And it points out a fundamental perspective when you start thinking about climate change — is that although all of us are exposed, that exposure is different from place to place. The climate is changing faster in some places than in others, and the risks you see in a particular location are different for those you see in another location. And so you need to take into account this local context to understand the challenges that we could be facing, the opportunities we have, the capacities that you have in those locations, and what can be done to ensure that we increase the resilience of the population so that as the climate continues to change, we don't see adverse outcomes.

Ariel Conn: I wonder as well if — would it be fair to say that because of climate change, everyone then is becoming more vulnerable? I ask because I think there's a sense, especially in the US, where, "Okay, yeah, it'll be bad, but it won't be as bad for us." And I think that that can actually be a harmful attitude, because the fact that it won't be bad for us: what we're experiencing will still be very different than our lifestyles now, or could be, I guess. And so I wonder if we have the wrong reference points when we're making that comparison.

Kris Ebi: All of us are exposed, and that will result in weather patterns in the future very different from the ones we experience now. The extent to which we're vulnerable to those will depend on the choices made. For example, heat waves are increasing in frequency and intensity and duration, but if we have heat wave early warning systems; if people are aware of the risks of heat; if people know what kinds of actions to take; if communities develop good response systems, they put in centers where people can go and cool themselves down during the day when the temperatures are really high — there's lots of actions that could be taken. So in the short term, as the temperatures continue to rise, we don't have to see an increase in mortality in heatwaves. Those can be prevented. The question is whether we constrain our greenhouse gas emissions, because if we don't, then later in the century we may reach the point where there could be places in the world that will be pretty difficult to live in because they're going to be so hot.

Ariel Conn: So spinning off the heatwave example: I read, I think it was an interview with you at some point, where one of the points you made that I didn't know — and I think this is an example of us not doing a good job of preparing and educating people — was just that as people age, they're less likely to recognize that their body is overheating. I thought that was really interesting. It's one of those little side effects that I just don't even think about yet. 

And then I also want to have you talk a little bit about vector-borne diseases, or even just diseases in general, and the impact climate change could have on them. I've got an interview that you did quite a few years ago now at this point, where an example you give is there was an outbreak in Anchorage of a gastrointestinal disease carried by a pathogen that grows in oysters, but that pathogen requires certain water temperatures before it can replicate — and the temperature in Anchorage had finally gotten high enough for that pathogen to survive. In the interview, you say previously the closest known case was 600 miles south. So I was hoping you could talk a little bit more about some of the disease problems that we could face.

Kris Ebi: That is a good example that comes from a publication out of Alaska, from an outbreak of a disease that's called Vibrio parahaemolyticus. It causes nasty gastrointestinal symptoms, and it did appear for the first time in Anchorage several years ago. Think particularly about the vector-borne diseases, and diseases are vector-borne because they're carried by mosquitoes or ticks for example, and when you look at mosquitoes and ticks, their geographic range is in large part — not entirely, but in large part determined by the weather patterns. If it's too cold for the mosquito, it won't survive, although some mosquitoes can overwinter in sewer systems. And similarly with ticks: you only see them in certain places. So it makes sense that as the temperatures warm, they're just going to continue to change their range, that they're going to expand from where they are now into other habitat that's equally as suitable.

This has been a concern with climate change and health from the beginning, of what could happen. One of the concerns, for example, is malaria. When malaria occurs regularly in a population, it's called endemic. The mortality rate is fairly low: it's a few percent, and it's typically in children under the age of five. When you have malaria appear in a region where it doesn't typically appear, you have epidemic malaria, and then the mortality rate can be over 10%. So you can have pretty high mortality and it's across the entire age range. And where we see epidemic malaria now is along the edges of its current distribution.

There's quite a large number of publications showing that with warmer temperatures, the mosquito is expected to expand its geographic range in some places. It may decrease its geographic range in other places that become too hot and dry, but in the new locations where it appears you could then have epidemic malaria — until malaria becomes well established and turns into something you see every year. Assuming you don't have a vaccine or something that can prevent malaria, then the projections all show, along the edge of the distribution, you're likely to see increased numbers in the cases of malaria. There's also concern for diseases like dengue, Zika, chikungunya and other viral diseases in that case that are carried by mosquitoes. So it is a topic of concern and a topic where considerable research is being done.

Ariel Conn: So I think this sort of comes back to my question about regions that think they're relatively safe possibly being a bit more vulnerable than they thought. I don't know if some of the wealthier northern countries are still going to be safe from malaria or dengue, but how far are we looking at something like that spreading? Or does that become an unknown?

Kris Ebi: There is good understanding of the environmental determinants of these vectors, so you can model, "What if water temperatures are warmer? What if precipitation patterns change?" That doesn't necessarily tell you where you might have disease transmission, because for example, the vector that carries the disease dengue, the mosquito, certainly in the US tends to be an ankle biter that bites in the morning and the evening. And those of us in the US typically live in houses with screen doors, and we don't get many mosquitoes inside our house. So we could be protected from exposure to that mosquito, except of course when we go out and have picnics on the weekend and when we go out and do other things.

Ariel Conn: Yes. I still manage to get bitten by mosquitoes a lot.

Kris Ebi: Yes, we all do. And there is some interesting research: A couple of years ago, some colleagues at the National Center for Atmospheric Research looked at this particular mosquito and looked at its current geographic range in the United States. And we don't have good surveillance in all of our states for this mosquito, so we don't necessarily know exactly where it is, but using the environmental determinants, you can say right now you'd expect the mosquito to be in the Southeast and in Texas, for example. And then looking at climate change, saying, "Where could you see this mosquito towards the end of the century?” In, for example, 2080. And then you see quite a big spread of where you could see this mosquito well into the Midwest. And the authors then asked a second question of, "When would the summers be hot enough and long enough that if you introduced the virus into a mosquito, you could actually have the disease?"

The mosquito obtains a virus by biting a person who is infected. The virus then travels to the gut of the mosquito where it replicates, and the rate at which it replicates is temperature dependent. So if it's too cold, it'll take the virus longer to replicate than the mosquito will live. And so you need to look at, how hot and how long is that summer? Can you actually have replication? And then showed that the range of possible transmission of dengue would be bigger than it is today, but not as far as the model suggests we could see the mosquito. And again, the mosquitoes' range, in this model, were projected to be into the Midwest. And in 2017, breeding colonies of this mosquito were found in Toronto, Toledo and Detroit: significantly under-projected where we're likely to see this mosquito. And again, just because we have the mosquito doesn't necessarily mean we're going to have disease transmission, but this mosquito is totally adapted to human environments, and as I mentioned, can do things like overwinter in sewer systems. And so we're seeing, when people look for it we're seeing the mosquito in more places where we thought it was before, which then raises concern about, as summers get longer and hotter — which they are — that it becomes more likely we could see disease transmission of some of these diseases in the US.

Ariel Conn: Another paper that you were involved in that I think is really interesting and a little worrisome: that was a study that found that rice actually has fewer nutrients in it if it's grown in an atmosphere with greater CO2, if I was reading that correctly. And possibly more than just rice — possibly other crops as well. I was hoping you could talk a little bit about that.

Kris Ebi: You're absolutely right. When you look at plants — to really oversimplify, there's two main ways that plants bring in carbon dioxide from the atmosphere. And most of the plants that we eat — not all of them, but most of them — have a particular mechanism. These are called C3 plants, and that's rice, wheat, barley, potatoes, also includes grasses. And as the concentration of carbon dioxide increases in the atmosphere, the plants bring more carbon dioxide in because they need that to grow. And that's why you read in the newspapers, for example, that CO2 is a plant food — it helps plants grow. The plants also become more efficient in how they use water, and so they absorb less micronutrients from the soil. There's also changes in essentially the plant physiology. It's also an oversimplification. You see in wheat, rice, and other kinds of C3 plants about a 10% reduction in protein, a 5% to 10% reduction in all the micronutrients, iron and zinc included.

As a reminder, there's 821 million people in the world who are food insecure, and there's two billion people who have micronutrient deficiencies. So micronutrient deficiencies is a much bigger problem. And in addition to the reduction in the micronutrients, the paper you reference, we show that there is a reduction in the B vitamins. For example, folic acid reduced about 30%, and when pregnant women don't get enough folate, they can have babies with birth defects. So we're looking at broad scale changes in the nutritional quality of much of our cereal crops. And that potentially could affect us; We estimated that in the major rice consuming countries with low GDP, we're talking about 600 million people could be affected. Other studies have projected a couple hundred million people being affected, depending exactly on what they looked at. And it would affect not only us, but it also affects livestock that are fed on these kinds of crops.

So the quality of our food overall is likely to decrease as carbon dioxide concentrations increase. And this is an area of high concern, and an area where there's quite a lot of research underway to better understand the magnitude of the challenge and the opportunities for trying to make a difference before all of our food quality goes down.

Ariel Conn: When you say a couple hundred million to 600 million people will be affected by this, is that in addition to the 800 million that you already referenced?

Kris Ebi: Yes. This is just specific to the changes in plants from CO2, and I will point out that different studies looked at different aspects. So some of the studies that project 200 million people could be affected are looking at specifically iron and zinc. They're not looking at the B vitamins, they're not looking at the change in protein or the change in the other micronutrients. There's not yet been a comprehensive effort to say when you put all these changes together what that could mean, or to say what does it mean on top of what we're seeing with climate change reducing crop yields in some locations.

Ariel Conn: Climate change reducing crop yields is a problem that I'd heard about. With respect to crops being affected by the increased CO2 in the air, would that be global or is that still a regional issue?

Kris Ebi: That's global.

Ariel Conn: So everyone is going to see a decrease in nutrients?

Kris Ebi: Correct.

Ariel Conn: It's just some people will be more negatively affected by that than others?

Kris Ebi: It depends on your overall diet.

Ariel Conn: Okay. So I guess the more diversity in your diet, the better?

Kris Ebi: That's right, and that's why in our paper we focused on the countries where you see the lowest GDP. When you look, for example, at Bangladesh today, even as they become wealthier, three of four calories comes from rice, and so the impact on those populations would be expected to be larger. China, of course, is making different choices as it develops in terms of the diversity of its diet, and more work does need to be done to look at how we can ensure that dietary diversity will supply the nutrition that we need for us to grow and be healthy.

Ariel Conn: Okay. This might be a little bit too speculative, but do you think we'll get to the point where we need to supplement the food in some way, or do you think most of the world will still be able to get the nutrients they need?

Kris Ebi: Today much of our food is supplemented.

Ariel Conn: True.

Kris Ebi: That's already happening, and if it was as effective as people would like it to be, we wouldn't have two billion people who are micronutrient deficient. Even in the States, we have far too many women and teenage girls who have iron deficiency anemia. This affects every country.

Ariel Conn: So we don't want to count, I guess, then, on being able to supplement.

Kris Ebi: Unless we find more clever ways to do it, where it's more effective than it is today. It should be one of the options we have available to us, but there needs to be more work done to identify additional options, to make sure that the entire population has the nutrition that it needs. Often people don't have broad dietary diversity because of economic forces: they're too poor. We have food deserts in the United States where it's difficult for people to buy a full range of foodstuffs even if they had the money to afford it. So we do have institutional and governance issues that need to be addressed as well.

Ariel Conn: I want to go back to some of what we were talking about earlier and just ask you — you've mentioned Agenda 2030, and there's lots of solutions — can you specifically highlight some things that you think are most important for us, either at an individual level and/or a more government level to be doing?

Kris Ebi: There's two key issues I would start with. Number one is increasing awareness — and your podcasts are going to help people become more aware of the risks — because there's really very little people can do if they don't understand what the risks could be. And the second: there is growing research showing that far too few Americans talk about climate change. We don't talk about it with our friends and family, we don't hear about it very much in school — that there is a real lack of discussion, and it would be quite helpful for people to, as I mentioned, increase their own awareness, but then start talking with those around them about their concerns, and better understanding how we can help facilitate the changes that need to be made. You mentioned early on that one of these is voting, and that certainly is critically important, and that's for all levels: that's for your city council and that's for your state legislature. But that's just one of many activities people can undertake.

Reducing your own greenhouse gas emissions saves you money, and helps reduce how much we put into the atmosphere; Increasing awareness of the risks, for example, of heat, is really important; Thinking about how you use water; We've got real issues with how much plastic we're throwing into our oceans. There's a broad range of activities people can undertake — collectively and individually — that can make a difference. In King County, where I live, where Seattle sits, every other year there's an award from King County to NGOs that are doing work towards sustainability. There was an award ceremony in April, and it was just lovely to see the kinds of actions different NGOs are taking — cleaning up local rivers and working to help save our salmon. There's lots that people can get engaged in that does make a difference and can give people a sense of purpose in making the changes happen.

Ariel Conn: I like the idea of the city or county recognizing groups that are making a good difference. It seems like that would be motivational.

Kris Ebi: I hope so, because there's so many opportunities for people to engage.

Ariel Conn: My one final question is sort of what you're hopeful for, but before we get to that, I was looking through a bunch of your papers, and I really wanted to get to a lot more of it, and I don't think we've got time. So I'm just curious if there's something that you've worked on that you think is really important that maybe people don't seem to understand yet, or if there's anything related to climate change that you think is really key that we haven't gotten into.

Kris Ebi: One of the key messages from the Intergovernmental Panel on Climate Change Special Report On Warming of 1.5 degrees is that it is possible to keep warming to below 1.5 degrees. We have the technology, and it certainly is possible to do this. What it takes is an action, to make sure in fact that we do undertake the actions that are needed. Another critical message from the same report is every action matters. It's not an either-or of individual or collective, do this or do that. It's every action matters, and we can all make a difference in lots of ways. And the better we understand that, the easier it'll be for all of us to collectively make the changes we want to see in society and to have a more resilient future.

Ariel Conn: Excellent. So, this may already have answered the question that I have for you to end with. Are you hopeful?

Kris Ebi: I'm a worried optimist. I teach at a university, and my classes grow every year. The energy and enthusiasm from students on this topic is absolutely amazing. The public awareness of this is increasing. Several years ago, the conversation we're having now would never have happened. You're seeing a very large increase in awareness, people wanting to take action, people looking for information. And that gives me hope that, yes, in fact we can implement the changes that we know need to be implemented in a timely way, and ensure that our future's going to look more or less like today and not look fundamentally different.

Ariel Conn: Well, fingers crossed. I've definitely, just from reading the news and a couple of the interviews that I've done so far, I am very hopeful that it will be some of the younger generations that will preserve our — and more importantly their — futures. Yeah. Anyway, I appreciate hopeful messages. Anything else?

Kris Ebi: No.

Ariel Conn: All right. Well, thank you so much for joining us.

Kris Ebi: Thank you.

Ariel Conn: I hope you’ve enjoyed this episode of Not Cool, a climate podcast. On our next episode, we’ll be joined by Val Kapos, who is the head of the Climate Change and Biodiversity program at the United Nations World Conservation Monitoring Center.

Val Kapos: We do need to stop talking and start doing. I would like to see ecosystem-based adaptation integrated into the way people think about responding to climate pressures. I think it's important that people start to consider what the natural world has to offer at the same time as they look for other options, and that we evaluate these options together. We look at complementarities.

Ariel Conn: As always, if you’ve been enjoying these episodes, please take a moment to like them, share them, and maybe even leave a good review.

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