How Can Regional Models Advance Climate Science?

Climate models have changed the way we view the world. While effective, these models are imperfect, and scientists are constantly looking at ways to improve their accuracy and predictability.

MIT professor Elfatih Eltahir has spent decades developing complex models to understand how climate change affects vulnerable regions like the Nile Basin and Singapore. In this episode of The Joy of Why, Eltahir tells co-host Steven Strogatz how growing up near the Nile in Sudan helped him realize that climate change doesn’t occur in isolation. To better understand climate-related impacts and to create more effective adaptation strategies, Eltahir says we need regional models that incorporate contextual data like disease spread and population growth. Eltahir also discusses his “Equation of the Future of Africa,” and he introduces the concept of “outdoor days,” which he hopes can improve public perception about climate change.

Listen on Apple Podcasts, Spotify, TuneIn or your favorite podcasting app, or you can stream it from Quanta.

Transcript

 [Music plays]

STEVE STROGATZ: I’m Steve Strogatz.

JANNA LEVIN: And I’m Janna Levin.

STROGATZ: And this is The Joy of Why, a podcast from Quanta Magazine exploring some of the biggest unanswered questions in math and science today.

Hi, Janna.

LEVIN: Hi, how are ya?

STROGATZ: I’m good. How’re you doing today?

LEVIN: Yeah, good. We’re back to it.

STROGATZ: We are. And our discussion is going to be about something I don’t think we’ve ever talked about with each other, which is climate change.

LEVIN: Yeah. I don’t think we’ve had that conversation, surprisingly.

STROGATZ: Such an important topic in science and world politics and the future of our planet, you know, what our kids are going to be facing. We hear about it all the time, how all kinds of records are being broken, in temperature, wildfires, droughts, sea level changes.

LEVIN: Yeah, I live in a coastal city. I live on an island.

STROGATZ: Oh, yeah, I heard that. Yeah. We’re referring here to Manhattan, yes? It’s true though, right? But so, I realized that I don’t really know as much as I should about how the climate projections are being made. We hear all the time about climate models, but what goes into those models, and what is really the science of climate prediction? Also, what do we know about how things are changing around the world, and how are those changes affecting people?

LEVIN: Yeah. I wonder a lot about how many models there are, if there are competitive models, but I think it almost surprises me how much they dovetail. How much they come together, but, you know, how do they get their data sets? Very difficult problem, actually.

STROGATZ: Well, so I sat down with our guest, Elfatih Eltahir, who is a hydrologist, a climatologist, a meteorologist at MIT. He taught me so much, I mean, I really learned a lot. And Elfatih, he’s originally from Sudan, and, you know, that appreciation that he has from growing up along the Nile underscores the point that climate change does not just occur in isolation. It has a very social and cultural dimension that we really can’t ignore both in our analysis and response to this issue.

LEVIN: Yeah, sure. We want to live on this planet.

STROGATZ: I think so. Anyway, on the science, we are going to hear from Elfatih Eltahir, MIT professor, so let me pass it over to him. Are you ready?

LEVIN: Yeah. I’m ready.

STROGATZ: All right, here we go. 

[Music plays]

STROGATZ: Welcome to The Joy of Why, Elfatih.

ELFATIH ELTAHIR: Thank you.

STROGATZ: I’m really pleased to have a chance to talk with you. I noticed that you hold degrees in all kinds of different fields — civil engineering, hydrology, meteorology, hydroclimatology. First, could you just tell us what is hydrology? I mean, I can guess what it is from the words. But how would you define it?

ELTAHIR: Hydrology is the science of the water cycle. The way I think about it is the water cycle in its full extent, from rainfall to infiltration of water into the soils, into overland flow, river flow, then the evaporation into the atmosphere. And then the transfer of that water in the atmosphere from one region to another until it drains somewhere else. Observing it, understanding it, predicting it is the subject of the science of hydrology.

STROGATZ: So, the movement of water through its cycle from rainfall into the land, the plants, the atmosphere, back again. Okay. And how about hydroclimatology?

ELTAHIR: In a way you could think about it as long-term averages of the variability in the hydrologic cycle, and how processes that happen in the atmosphere, leading to formation and fall of precipitation, are connected to evaporation, soil moisture, and conditions over land.

STROGATZ: Now, one of the distinguishing things in your work is this attention to the social considerations along with the climate ones. How necessary do you think it is to take that multidisciplinary perspective, bringing both the social and the scientific together?

ELTAHIR: Yeah, that’s very important. The way I describe it is bringing the context, over which climate change is happening at regional and local scales. I tell my students that climate change doesn’t happen in a vacuum. It happens in a context. When we emphasize heat waves in Asia, those are regions that are already experiencing lethal heat waves. And people are suffering because of that. If you look at disease in Africa, like malaria, too many children die from malaria in places like Nigeria and other corners of the continent. You look at phenomenon, for example, like water availability in the Nile. Even without climate change, there is a conflict on water. There’s too many people, too little water. There is already a system under stress.

Understanding how climate change is going to impact society could not be developed thoroughly without understanding the context and the history. And so, carrying these climate studies at a regional scale, allows us to not only look at what the physical climate models are telling us, but to interpret those in a context where social processes and where society is already engaged in addressing complex and acute problems.

STROGATZ: So, we’re going to spend quite a bit of time in our conversation about the Nile. And before we get into the science and engineering aspects of it, I understand that you have some personal connection to that part of the world.

ELTAHIR: Yes, I was born like a few hundred meters away from Nile, in a city in Sudan called Omdurman. That’s where I grew up. That’s how I learned about the world, early on, seeing that a huge amount of water flowing down to Egypt every year, the flooding of the Nile, the flooding season and the dry season. For a while, I thought the whole world looked like that. You know, you have a river flowing and then you have deserts, and I was more interested in the rivers than the desert.

STROGATZ: So, for those of us who haven’t been there, can you give us a little more description of the terrain?

ELTAHIR: So, Sudan is pretty much a desert region. The river flows from the south to the north across that desert and brings in huge amounts of water into Egypt. The area right next to the river is utilized for agriculture for like thousands of years. So, there is greenery, there is palm trees, there is agriculture. And that’s basically how life in Sudan was shaped through centuries.

STROGATZ: Well, you’ve given us some indication already of how important the Nile is to Egypt, Sudan. It touches many other countries, doesn’t it?

ELTAHIR: Yeah, the Nile actually travels across 11 countries. There are two main tributaries of the Nile. The Blue Nile comes from the Ethiopian Highlands. It comes with very strong flows and erodes very strongly into the Ethiopian Highlands. And it brings a lot of sediment, so the color of the water itself will be darker. The White Nile, it travels long distances through South Sudan, through relatively flat landscape, and so the color is not as dark. They meshed together in Khartoum, the capital of Sudan, and then they carry together as the Nile, and that travels until it discharges in the Mediterranean.

In hydrology, the most important equation is the water balance equation. Other countries contribute to generation and to consumption of the water, but like 80% of the water is generated in Ethiopia and 80% of the water, roughly, is consumed in Egypt.

STROGATZ: Once it became clear to you that you were interested in a life as a scientist, did you always think that you would come back to studying the Nile, having grown up, you said, only a few hundred meters away from it?

ELTAHIR: That actually is a very interesting question that I wonder about myself. I found myself going back to study the Nile intensively, but I was just naturally drawn to look at that system and to study it. It didn’t happen by plan. I remember the first paper I had about the Nile was actually after I finished my PhD. People started learning about this phenomenon called the El Niño phenomenon. Every few years, you get a warming pattern in the Pacific Ocean, and it impacts weather and rainfall, around the world and mostly in the tropics. I got my hand in that data, and I noticed that El Niño seemed to correspond to years in which we have drought in the Nile.

STROGATZ: Oh really? Drought, huh?

ELTAHIR: Yeah. That discovery did not happen through a computer or plotting a graph. It’s just looking at the data. That took me to get the data to do analysis, to do statistical significance testing, and so on. And I published a paper in 1996, in which I argued that 25 to 30% of the inter-annual variability of the Nile is associated with this phenomenon, which is El Niño–La Niña. When you have warming in the Pacific Ocean, you get drought in the Nile. And when you have cooling in the Pacific Ocean, you tend to have flooding in the Nile. The story of the seven years of flooding and the seven years of drought was mentioned in the Bible and in the Quran about, you know, a dream of that nature. And even if you don’t believe in those religions, the natural variability of the Nile has been a subject of interest to civilizations for thousands of years.

STROGATZ: Wow. It’s a really fascinating story. First of all, this timescale of seven years, seems to be about right with what we think of for El Niño itself. Is that right?

ELTAHIR: Yeah, it’s around that. When you do spectral analysis, it peaks at that time scale. So, you have the coherence between the two signals — the sea surface temperature in the Pacific Ocean, the river flow in the Nile — are coherent at those time scales. But following that, there have been actually measurements of the water level in the Nile for almost a thousand years. I wrote a paper in which I described that as the longest record of a geophysical phenomena. This is not like peri-climate records that you get from data, but people recording, measuring the level, and they were doing that for reasons that has to do with the taxation of the population. And so, there is measurements from a device they call Nilometer. I used in another paper that record to look at the occurrence of El Niño and La Niña in the past.

STROGATZ: Hmm. On the face of it, it seems pretty unbelievable that something happening in the Pacific — I don’t know how many thousands of miles that is from the Nile — but it must be close to halfway around the world or something. And yet, somehow, through what it’s doing to what, the jet stream or something it’s affecting the weather in Africa?

ELTAHIR: Mm-hmm. A simple picture you could think about is, for rainfall to occur anywhere, you have to have air going upward. So, when you have different rainfall patterns over the Pacific that enhances the upward motion in the Pacific, and that air has to come somewhere else. And some of it comes over the Ethiopian Plateau and inhibits the rainfall over the Nile. That’s a simple way of describing it, but it’s quite an interesting geophysical, what we call, teleconnection.

STROGATZ: Teleconnection, I see.

ELTAHIR: Yeah, they call it the teleconnection when you have two phenomena, that are so far apart, having physical connection that explains some of these statistical associations that you observe.

STROGATZ: Well, let’s talk about, now, climate and its interplay with the Nile. And, in particular, the use of regional climate models as opposed to global. So, I wonder if you could walk us through why it’s important to look at regional scales, what regional scales actually are in terms of distances, that kind of thing?

ELTAHIR: Yeah. My focus in climate studies has been consciously at the regional scale. We need to understand climate phenomena at regional scales for two reasons: To be able to inform society about how climate change is going to impact them directly; but also to be able to inform how those climate-change impacts are going to be distributed. People need to know the details of that so that they could design their adaptation strategies.

I started looking at regional models during the period of my PhD work. And my PhD topic was about how deforestation in the Amazon could impact the regional climate of the Amazon itself. And so that was the first time in which I built a model of the regional climate around the Amazon, because you are not focusing on the global scale, you focus on a regional scale. You can always have more detailed representation of the processes, more detailed representations of things like topography and coastlines and land cover. All are elements that are important in shaping the regional climate. And because of the high resolution, you could then connect directly to where people live. You could describe, for example, in a state like Massachusetts, where I live, how conditions could be different in the eastern side of the state versus the western side of the state.

STROGATZ: Oh, really? That fine scale?

ELTAHIR: Yeah. We could go down now to models that have resolution of about 10 to 20 kilometers, while the typical, global climate model would have resolution in the order of a hundred kilometers. The downside to that is you always need to have information to constrain the models at the boundaries. That’s the price you pay. And we could give that information to constrain the boundaries, either from archived observations, or we could get it from simulations that are performed with global climate models.

The way I like to think about the regional climate model is like a numerical laboratory, that is set up for a certain region, to study climate processes at that scale. And it allows to incorporate knowledge about details of the hydrology, or the agriculture, or the weather systems, that have been gained and accumulated through time. We integrate that in our climate studies of that specific region.

STROGATZ: So, let me just flesh out a few examples. You’ve already touched on some. You mentioned Eastern and Western Massachusetts. You mentioned the Amazon, that would be a much bigger region. There’s the Nile River Basin. Would that be considered a region?

ELTAHIR: Yes. We run our model on the sources of Nile, which is like the Ethiopian Highlands, the Ethiopian Plateau. The topography of that region is an important factor in generating the rainfall over the sources of Nile. And if you try to simulate the formation of rainfall over the sources of the Nile, using a global climate model, the resolution of the model would not be sufficient to represent the details of the topography that exist in reality. And so that’s the kind of process that we try to incorporate and successfully do when we use regional climate models.

STROGATZ: I would like to ask one technical thing, being a mathematician and a modeler myself. For people who aren’t used to what these models look like, can you just tell us, in a little more detail, like, are you solving systems of coupled partial and ordinary differential equations for motion of air, for humidity, for temperature? I mean, what is it that you’re actually doing? Is it all in the computer? Is there some other way, in an analog of a wind tunnel or something? I mean, how do you do your studies?

ELTAHIR: So, climate models are numerical models. They are numerical solutions of a set of partial differential equations — coupled partial differential equations. The way I describe them to my students is, you could think of seven principles described with seven equations in seven variables. And the principles are conservation of water mass, air mass, conservation of energy, conservation of momentum in three directions, and the state equation for air, the ideal gas law. So those are seven principles. You describe them with seven equations. And you solve for seven variables, which are pressure, temperature, humidity, density and wind in three directions. So, you have seven equations, seven variables. You solve them on a sphere for the atmosphere. You solve a similar set of equations for the ocean, you couple them.

When you come then to describe impacts on things like disease and agriculture and others, you have to develop other models that are tailored to describe those phenomena in accurate ways. Always you develop the models and you test them against the past climate. So, we have a lot of data for the last number of years — at least 30 or more years — and we test the models against those, we calibrate them for those conditions that have been observed before we use them to project the future. And this process is an ongoing process, we are always coming up — not just my group —but globally scientists are coming up with better models. They are better representations improving on their accuracy, and they’re reducing the uncertainty. And that’s an ongoing process that happened in the past and will continue to happen in the future.

STROGATZ: I expect that you wouldn’t just run one model at a time. You must have an ensemble because of parameter uncertainties, is that right?

ELTAHIR: Absolutely. There are like 40 centers around the world that are running models all the time. Each center has several models and each model is run different simulations. So, an ensemble of realizations for the same phenomena. It’s a very sophisticated modeling system that has been developed through the work of hundreds and thousands of scientists. It’s a very interesting and very exciting experiment and experience that have been performed by the climate modeling community for all these years — rooted in mathematics, in good mathematics and good physics.

[Music plays]

LEVIN: Well, I have a lot of questions. I mean, seven parameters actually doesn’t sound like a lot.

STROGATZ: In saying seven, these are fields, right? It’s a velocity field, and a humidity field, and a temperature field across the whole sphere. So space is in there and time. These are spatiotemporal fields, seven coupled partial differential equations, all in space and time. So, you can look at the global scale — you often hear about global climate change. But one of the really special things about Elfatih is he looks at a scale that is very regional and sometimes even local.  Like, you know, what’s the weather in Manhattan, or what’s the climate over Massachusetts or in Sudan or the Nile? And that’s a really interesting math problem as well as important climate problem.

LEVIN: Yeah, I was intrigued that he was saying, look, of course our models get ever better, and there are all of these centers, we have lots of different ways of modeling to try to have some kind of resonance and way of improving those results. But it’s still such a tricky problem. It’s just so complex. And you study chaos, so you know how delicate this is.

STROGATZ: Yeah, that’s an interesting issue. He’s very aware of chaos theory, as everyone is who studies both weather and climate. But we’re going to hear more from Elfatih Eltahir about climate change. So, stick around and we’ll be right back.

[Music plays]

STROGATZ: Welcome back to The Joy of Why. We’re here with MIT professor Elfatih Eltahir, and we’re discussing climate models and the changing climate itself.

For people who haven’t had a chance to visit the Ethiopian Highlands, I being one of them, it sounds like a beautiful part of the world. It’s very green, it’s a plateau. Tell us a little about it.

ELTAHIR: As you describe it, Ethiopia versus the surrounding countries, which is Somalia and Sudan, Ethiopia is elevated. The temperature is significantly cooler. And the rainfall-producing mechanisms are much more efficient. If you think about it, fundamentally from the geophysics, the Nile water flow for all these thousands of years, is because of the existence of that geological formation. It had also a lot of implications later on in our studies to impact of climate change and variability on things like crop production, but also things like disease transmission, mainly vector-borne diseases like malaria and dengue and so on. Again, a topic that I found myself steered towards studying and putting time in, mainly driven by my own experiences when I was living in that part of the world.

STROGATZ: Well, you mentioned your own experience. Did you yourself ever suffer from malaria, or people in your family or friends?

ELTAHIR: Actually, I have a story. When I was a student in the University of Khartoum in Sudan, I experienced many incidents of being infected with the malaria parasite. And, I used to go, like, spend time in the university, and then by the weekend I would really catch malaria. I go home, my sister is a doctor, and I bring her the injections and she gives me the injections. So, the first thing after I got my tenure at MIT, I had a friend of mine who was a professor at Harvard School of Public Health, I said, “Oh, can we collaborate on this? We have a lot of good stuff with very sophisticated climate, hydrology modeling. Can we bring in that into the study of malaria?” He introduced me to a colleague of his and we started working together. We collaborated as a team of hydrologists, entomologists and medical scientists, and we were able to develop very sophisticated models of how climate variability and climate change impact malaria transmission in African villages.

And the thing about it is, it wasn’t just modeling work because we extended collaborations with Harvard, with Pasteur Institute. They have local institutions in Africa, in Niger, in particular, where we were able to collect a lot of very detailed data in the environment of villages in Niger on things like rainfall and temperature, but also on mosquitoes, their numbers, different species of mosquitoes. But also data on prevalence of the parasite in the blood of children and so on. It’s a very detailed model, I think one of the most sophisticated models of disease transmission. When Covid hit society years ago, I wish then that we had a model of the transmission of influenza or these viral diseases of the same level of sophistication.

What we discovered is actually very, very interesting, too, is a lot of the climate studies will come with this, like, very negative projections. What we learned is that in Niger, climate change is not likely to worsen the situation. The situation is not good, but climate change is not going to make it worse. Which later on was not the case when we looked at the Ethiopian Highlands. As the climate warms up, that opens the Ethiopian Highlands for malaria, subjecting a population that has very little immunity to this disease.

STROGATZ: Is the work on the Nile and malaria a kind of case study in what the rest of the world can be expecting as far as impacts of climate change on disease transmission, on some social factors, or whatever?

ELTAHIR: That’s an interesting question. So, after I did my study on malaria for years, I had the opportunity to do research in Singapore. I shared with them that, you know, we have done this work on malaria in Africa, and it may have some relevance to a disease that’s really a big problem in Singapore, which is dengue. They were a little bit skeptical initially. But we finally, actually, made significant progress in understanding the environmental side of how dengue is transmitted in Singapore. Singapore is a country with a very efficient public health system— very well-funded, very well managed—but they’re having a problem with dengue. They have houses that have been visited by the public health specialist, and they found evidence for the breeding of the Aedes mosquito, the mosquito that transmits dengue. In the case of the malaria, it’s the Anopheles mosquito, which is a different species. So, a graduate student of mine made a discovery that when the Singaporean authorities went very strongly against the Aedes mosquitoes breeding inside homes, the mosquitoes were smart enough to find the niche where they would breed outside the homes, in small drains. And that’s why their management of the problem had not been as efficient as it could have been otherwise.

After a few years studying dengue in Singapore, I came to the US and I was approached by the Department of Public Health in the state of Massachusetts, because they have concerns about the mosquito that transmit dengue creeping into the state of Massachusetts. And my main advice to them was, the time to go after Dengue is not when dengue flourishes and becomes a full-blown disease. When these mosquitoes are struggling to establish themselves, that’s the time you go after them vigorously so that you eliminate them. What we learn about dengue in Singapore could help us develop strategies.

Another aspect I could talk about is the regional climate of the American Midwest. If you look at the Midwestern US and you look at the summer climate, you don’t see warming of temperature, as happened around the world, but you see actually cooling. And we attribute that to the changes in land use and land cover, the development of agriculture, more intensive agriculture, development of irrigation that happened during the 20th century, and increasing the rates of evaporation, a cooling process. Evaporative cooling is very efficient, and so, as a result, we develop better understanding of the regional climate of the Central United States — an understanding that should help us interpret the trends of global warming that are happening around the world.

STROGATZ: Well, those are great examples, and I think you’re making the case, pretty clearly, that the lessons we learned from studying places like the Nile or Singapore are very relevant to things that may be happening closer to the US. Taking that as now established, let me just ask a little bit about some social factors, as revealed in some of your studies, things like population growth, increasing agricultural needs? Do you want to talk about some of that?

ELTAHIR: Yeah, that’s actually an important topic, I think. In a recent book, I coined a term describing an equation, I call it “The Equation of the Future of Africa.” It’s a simple, actually, mathematical equation, which says the future economic growth is function of climate change plus technology adoption minus population growth. And I mean by technology here things like fertilizers and better seeds and so on. So that’s how we use water. And so those, I think, determine the future of Africa. It’s how do we manage trends in climate, trends in technology adoption and trends in population.

I am a believer that population growth — uncontrolled population growth — is the number one threat of the future of the African continent. In Africa, the projections are roughly that the population of the continent, which is about a billion, is going to double by 2050. I’m not a demographer, but one thing I learned looking into the literature is that demographic models are much more accurate than climate models, because of the concept which we call the population momentum. So, when you do analysis on water, on, like, agriculture, on many factors, you find that the impact of the growth in population is significantly larger than the impact due to climate change or any other process.

STROGATZ: Right, there’s a lot of spinoff effects of having large populations growing quickly.

ELTAHIR: Exactly. But also, think from the perspective of the African population, it’s even more alarming the kind of suffering and the kind of disruptions and wars and famines that the existing populations will have to go through in absence of better management of these trends. Climate is changing and population is changing rapidly. So, I think that framework, I describe where we have to control and manage those trends in addition to, of course, the role of technology.

The role of technology, I didn’t say much about it. It’s mainly agriculture technology, and mainly technology that have proven elsewhere, like use of fertilizers, for example. I’m a strong supporter for the expansion of the use of fertilizers in agriculture in Africa. A lot of people look at fertilizer as a bad word, as like negative to the environment. It is a contributor to climate change, to water pollution in other regions of the world. Africans have been using significantly less fertilizer than the rest of the world to the detriment of the productivity of agriculture.

In addition to having a growth in population, that’s expanding rapidly, the African farmers have been working very hard, producing very little, because technological advancements that have been developed and applied and used in Europe, in North America, in China and India, they did not find their way to really help the African farmer produce more efficiently. That technology is a proven way to improve productivity, and hopefully, that improved productivity taken with control of population, with management of the climate, could open a better future for the African continent.

STROGATZ: This question about, uh, differential use of fertilizers in the different parts of the world raises a kind of ethical question, on a slightly different point, that so much of the pain of climate change is being borne in Africa, even though they did not contribute very much to causing climate change.

ELTAHIR: Yeah. When I think of the issue of climate, I think of three dimensions. There is where the emissions are coming from. Emissions, they did not come uniformly from around the world. In terms of impacts, the impacts are not impacting the world uniformly. And then the last thing is the ability of different communities around the world to adapt to climate change is not uniform too. There are societies in North America, in Europe, in Asia, that have the capacity to adapt to climate change. They have the institutions that could plan strategies to adapt to climate change. And there are resources. That does not exist uniformly around the world. And so, when I look at Africa, they did not contribute to the problem in the first place. The impacts on, of climate change on Africans are very severe. Not uniformly. Like, I gave the example of how malaria in Niger is not going to get worse. And then the capacity to adapt is not there.

One recent concept that we developed in my group is the concept that we call “outdoor days.” An outdoor day is defined as a day like we have today in Boston, like the maximum degree today is 18 degrees centigrade. And following this conversation with you, I am eager to go out and go for my daily walk. It is a nice day for a daily walk. This is what I call an outdoor day. And this is how we humans interact with the climate system. It’s a resource. It is like when we have a nice day, we go out, we enjoy it. Our standard of living would be higher when we do that. Our culture would be richer when we are able to do that. And what we discovered in that is study, unfortunately, that the impact of climate change on outdoor days is not uniform around the world. Countries in the tropics, mainly in Africa, and also some in South America and Asia, are going to suffer a reduction in outdoor days. Where we live here, where I live in Massachusetts, we are going to have more outdoor days in the spring and in the fall, maybe some in winter, and less outdoor days in the summer. In total, we get the same total back again, very small difference.

But you go to places like in Bangladesh or Sudan or like Nigeria, and you see dramatic reduction in the number of outdoor days. That, I think, is a serious negative impact of climate change, and it’s going to have implications. Cultures are going to be impacted and ways of living are going to be impacted and standards of living are going to decline. The important lesson is that, when we think of climate, the world is not flat. It has its, like, ups and downs. And so exactly what you were saying earlier, there are ethical issues, there are issues of justice, and so on, that are deep, that society will have to deal with. I think our role in science is not really take sides in that sorting of different groups in society, but informing all of that, because we provide numbers and quantifications of impacts that are neutral but inform society to have the right dialogue about these important issues.

STROGATZ: I really appreciate your mentioning this concept of outdoor days. As someone who cares a lot about science communication myself, I think you’ve really done something extremely important with this new concept. Because so often the discussion about climate change, where we talk about global temperature going up by a certain date or something like that, or even the Antarctic ice — it’s not that they’re abstract, but it’s a little bit hard to relate to them.

Whereas when you say, I’m not going to be able to go gardening as often, or to ride my bike or play with my kids outside, people will really feel that. Or, in regions like say the Pacific Northwest, they may actually benefit in terms of number of nice outdoor days. As you say, the world is not flat. Some parts of the world will experience climate change as a net positive for them in terms of outdoor days, but still. Anyway, the main point was I think you’ve really made it very down to earth for people to understand what some of these effects will be.

ELTAHIR: I appreciate your comment about that. I really think it’s a significant ingredient to educate people about how climate change is going to impact them directly. One thing that we also did there, we developed a way — we have it on our website —so that the individual reader could participate in the analysis by selecting what do they regard as an outdoor day. What range of temperatures do you like to have? And then we dig into the models, and then we tell you this is how that outdoor day numbers are going to change for you. I like that because it really brings the user into the analysis. Usually we tell the public this is how things are going to change and you should care about them. Now they’re going to tell us, this is what we care about. And then we tell them, this is then how it’s going to change if that’s what you care about.

You know, one thing I want to say about climate change, which is we all know that there are lots of uncertainties about the projections of how the future is going to look like. There are uncertainties about that. And when people tell us, oh, our models are not accurate — yes, our models are not accurate because the history of science will not stop today. They’re going to be people who are going to develop better models. They’re going to have better studies. I mean, the future is open for the young generation of scientists to come in and become better than us with better studies and better, more accurate projections.

However, I tell people the uncertainty we have goes both ways. The models may be over-predicting, but the models could be also under-predicting what’s going to happen. And, if anything, the more like we go through summer after summer and we see the news, I’m inclined to think the latter. But the idea is not to dictate the debate, but to inform it. So that when people take positions about climate change and like, you know, is it real? Is it not real? Should we invest in mitigating it, or not? They make those decisions and those discussions based on facts and the best of science rather than anything else.

STROGATZ: Mmm. Well, let’s close then with this question. You’ve talked about people making their own decisions based on having information. Would you say that’s one of the main things that is motivating you to do the work you’re doing, to help the public here and in other parts of the world? Or is there something else? Like, what is it that motivates you to do the work that you’re doing?

ELTAHIR: I think two things. Informing society about how these changes that are happening, how they’re going to impact things that they care about — water availability, extreme weather, diseases — those are things that people care about. How are they going to change in their own communities? Not just like a global picture. That’s why we use the regional models. That’s one factor.

The other, increasingly, is to help inform adaptation to climate change. That also needs to be built based on facts. And very briefly, this is my most recent engagements now. I am directing two programs — one in Morocco and one in Bangladesh. The one in Morocco is about water availability, coming up with solutions on how people could adapt to less water in the future. Climate projections are that, not only Morocco, the whole area around the Mediterranean, it is going to have less water in the future because of climate change. So, we are working on adaptation there.

And then there is this project we have in southwest Bangladesh, where they did not contribute to the problem in the first place, they are going to be impact severely because heat waves are going to be lethal, cyclones are going to be lethal, and they don’t have the capacity to adapt to those changes. And so we have a program there with collaboration, with local collaborators, to try and empower the local population with information and work with them to develop solution that would help them adapt to that future climate. So that’s the second part. One is inform mitigation. The other is inform adaptation.

STROGATZ: Well, Elfatih, this has been extremely informative. You have come a long way since growing up a few hundred meters from the Nile. Thank you so much for sharing all your expertise with us.

ELTAHIR: Thank you very much. I really enjoyed talking with you, and I wish you all the best.

STROGATZ: Well, thank you very much for joining us on The Joy of Why.

[Music plays]

LEVIN: Hmm, in these projections for the future, sometimes you can feel helpless. What are we going to do? Nothing can be done. It’s all too late. But then he said something very interesting about adaptation. I mean, is he suggesting we’re going to survive, but we’re going to have to adapt?

STROGATZ: I mean, I don’t think it’s some kind of either-or choice. I imagine that he would like us to be talking about what we could do to improve the current situation, but given the track record, yeah, I think we want to be on all fronts here. And that’s what he’s suggesting, yes.

LEVIN: Mmm-hmm. Now, I like hearing about the climate science. It’s such a social and politically charged conversation that I’m just curious how a person handles that in their scientific work.

STROGATZ: You know, we all need to be better informed about the science, and it is all too easy to just start lapsing into despair or talk about the political dimensions of it. I feel very strongly about the science communication part. There’s a psychological dimension. If we’re going to make any progress on either adaptation or mitigation or actually improving things, how are you going to get through to people? And people have tried many things, you know. But this idea of outdoor days, maybe that’s a good way of piercing the bubble. I don’t know.

LEVIN: Hmm. Well, yeah, asking people what they care about.

STROGATZ: Yeah. Right. Letting people say, not just top-down, but get the people themselves.

LEVIN: Tell us what you care about, and we’ll tell you.

STROGATZ: Right. You tell us your values will tell you what’s likely to happen. Also, very humble and realistic for him to say, of course, the models are inaccurate. That’s the beginning of science, right? The next generation will improve it. That’s always the case.

LEVIN: Mmm-hmm.

STROGATZ: There’s just a lot to think about, and maybe a lot to act on. It’s, uh, sobering, and yet exciting. I mean, there are a lot of opportunities to work in a very important area and really scientifically challenging area.

LEVIN: Yeah.

STROGATZ: All right, Janna, pleasure to be with you as always.

LEVIN: Pleasure. Hopefully we’ll be able to hang out outside soon.

STROGATZ: Yes, let’s have some outdoor days together.

[Music plays]

LEVIN: If you’re enjoying The Joy of Why and you’re not already subscribed, hit the subscribe or follow button where you’re listening. You can also leave a review for the show. It helps people find this podcast. Find articles, newsletters, videos and more at quantamagazine.org.

STROGATZ: The Joy of Why is a podcast from Quanta Magazine, an editorially independent publication supported by the Simons Foundation. Funding decisions by the Simons Foundation have no influence on the selection of topics, guests, or other editorial decisions in this podcast or in Quanta Magazine.

The Joy of Why is produced by PRX productions. The production team is Caitlin Faulds, Livia Brock, Genevieve Sponsler and Merritt Jacob. The executive producer of PRX Productions is Jocelyn Gonzalez. Edwin Ochoa is our project manager. From Quanta Magazine, Simon Frantz and Samir Patel provided editorial guidance with support from Matt Carlstrom, Samuel Velasco, Simone Barr, and Michael Kanyongolo. Samir Patel is Quanta’s editor in chief. Our theme music is from APM Music. The episode art is by Peter Greenwood, and our logo is by Jaki King and Kristina Armitage. Special thanks to the Columbia Journalism School and the Cornell Broadcast Studios.

I’m your host, Steve Strogatz. If you have any questions or comments for us, please email us at [email protected]. Thanks for listening.