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INTRODUCTION: Good evening. Please help me welcome your personal astrophysicist, Neil deGrasse Tyson. [APPLAUSE]

NEIL DEGRASSE TYSON: Welcome back. For whom among us is this your first time attending an Asimov? You know, we’ve been doing this for 25 years. Like, where have you been?

First, some housekeeping. Suni Williams and Butch Wilmore have arrived safely on Earth's surface. The two stranded astronauts, stranded in a 2000 square foot apartment with a half dozen other people, food and water, were stranded. Professional astronauts, who've been up there hundreds of days each, were stranded and just rescued today. Just thought I'd mention. [APPLAUSE] 

A couple of other notes. This is the 26th annual Isaac Asimov panel debate. This was formed on a gift from Isaac Asimov's estate, at the time overseen by his widow, Janet Jepson Asimov. Isaac Asimov was a friend of this institution. More specifically, of his 600-plus books that he wrote, rumored to have at least one book in every branch of the Dewey Decimal System. Yeah, that's pretty good. If you're you're a prolific author, you can say that. He did most of his research for his science fiction and his non fiction contributions to literature in our research library, and so we feel sort of genetically connected to him. And this panel debate is in his honor, in living memory of his contributions to the civilization. 

And again, I am Neil deGrasse Tyson. I'm the Frederick P. Rose Director of the Hayden Planetarium. And I also want to thank you. You already applauded, so I don't need a double on that. And I just want to recognize that this evening, we have Sean Decatur, president of this institution, with us in the audience. Sean, thanks for coming. [APPLAUSE] We spend months debating, discussing what the topic each year should be. And we want it to be scientifically interesting, a little bit challenging, perhaps. Also, culturally relevant. And this year's topic just ticks all those boxes, perhaps more so than any other subject we have presented, and that is the topic of geo-engineering. And, you know, you shake just saying the word. Even if you don't know what it means, it's like, “Oh, that means something important,” which, in fact, it does. 

So we are going to— we’ll have a panel of six. Each member of the panel will briefly introduce themselves, and I will come at them with this series of questions that we will openly discuss. None of us are presenting to you. We are having a conversation among ourselves, and you are eavesdropping on this conversation. Scientists arguing with each other. And from our polls and from our understanding of what people value, that is very high on the list, because it's too easy and too often where a scientist comes in and gives you a polished presentation. I want you to see what goes on in the coffee lounges of conferences. And because science— on the frontier, on the bleeding edge, we don't always agree. And it can be illuminating to learn the ways in which we disagree, and how we resolve them. If we resolve them. 

So allow me now to just bring out all six panelists. And they will then introduce themselves briefly before we get into the conversation. Come on out, all six of you. Here we go. [APPLAUSE] You, Kevin, tell us about— give me three sentences, who you are, and why you're here. 

KEVIN SURPRISE: Hi everyone. I am Kevin Surprise. I'm a Professor of Environmental Studies at Mount Holyoke College. I've been studying the economic and geopolitical questions surrounding solar geoengineering for about a decade now, trying to trace and understand how these technologies are being integrated into climate policy and why that might be a bad idea. 

NEIL DEGRASSE TYSON: Or why it might be a good idea. 

KEVIN SURPRISE: Why it might be a good idea, but probably not.

NEIL DEGRASSE TYSON: Okay. Don’t pre-judge. Let it— it can be a good idea. Holly, please. 

HOLLY JEAN BUCK: Hi, I'm Holly Jean buck. I'm a sociologist. I work at SUNY Buffalo. And I go out and talk to people. I do interviews, focus groups, surveys, not just because I'm curious what they think about these emerging technologies, although I am, but because I want to learn about how the public can have more influence in shaping how these conversations go and how these technologies get deployed or not.

NEIL DEGRASSE TYSON: And we never know if we have any influence at all, the way things go, typically. Yeah. Beth. 

BETH CHALECKI: My name is Beth Chalecki. I'm an Associate Professor of international relations at the University of Nebraska Omaha. And I've been interested in security my entire academic career. And it wasn't until a trip I took to the former Soviet Central Asian states when I realized the environmental damage that comes along with producing nuclear weapons. And that's when I realized how important the field of environmental security was. If we don't secure the environment, we don't have anything. So geoengineering just seems to be the wickedest of wicked problems, and I'm interested in learning more about it.

NEIL DEGRASSE TYSON: You already used the word wicked in your description of it. 

BETH: Wise.

NEIL DEGRASSE TYSON: Yes. Okay, tell us about yourself. 

DUSTIN MULVANEY: Hi, I'm Dustin Mulvaney. I'm a Professor of Environmental Studies at San Jose State University, and I study decarbonization strategies and the impacts of emerging technologies, with an emphasis on solar power and lithium ion batteries. So I think about, probably, alternative strategies to geoengineering in solving the climate crisis. 

NEIL DEGRASSE TYSON: You say lithium batteries, but also any minerals at all that would have value to the emerging technologies. 

DUSTIN: Any critical minerals, yep. 

NEIL DEGRASSE TYSON: Critical minerals, sure. All right, Howard, what you got for us?

HOWARD HERZOG: Hi I'm Howard Herzog. I'm from MIT. I'm a chemical engineer by training, and my focus has been on energy systems for the past 35 years, and basically low carbon energy systems. I've done things like geothermal energy. But the bulk of my research moved toward carbon capture and storage, which is capturing CO2 from point sources like power plants, before it gets into the atmosphere. And then it's got me into looking at removing CO2 from the atmosphere once it's already up there. I have a book coming out in August called Carbon Removal, and that's on this topic. 

NEIL DEGRASSE TYSON: All right. And Daniele, talk to us.

DANIELE VISIONI: Hi everyone. I'm Daniele Visioni. I'm a Professor of Climate Science at Cornell University in the Department of Earth and Atmospheric sciences. I am a climate scientist, a climate modeler, and for all of my research, I've tried to push forward our understanding of the climatic impacts of solar geoengineering. And I take the probably naive view that having good, robust, scientifically-backed information about something can help us make better decisions about that thing. I still think that's true. So here I am.

So you're the wicked one.

NEIL DEGRASSE TYSON: So you’re the wicked one. 

DANIELE: I am the wicked one. I've been called that many times. Yeah. 

NEIL DEGRASSE TYSON: And you're Italian. 

DANIELE: And I'm Italian, if you hadn't heard from the way Neil pronounced my name. Yeah. 

NEIL DEGRASSE TYSON: Daniele Visioni! 

DANIELE: I love it. 

NEIL DEGRASSE TYSON: So let me start with you. So you were a fan of changing the reflectivity of Earth, using aerosols in the upper atmosphere to reflect back sunlight, so that there's less energy on Earth to heat us up as a solution to our climate change problems. Could you just describe what that involves? 

DANIELE: I'll have to take a step back and say that I'm neither a fan, nor do I think it's a solution. But I think it is an— it could be an interesting part of a much broader solution. And yes, fundamentally, I've been studying the behavior of stratospheric aerosols, so tiny suspended particles in air. We've known for a long time that these particles are everywhere around us. And in particular that if any kind of source, whether human or natural, releases sulfur dioxide into the atmosphere, this sulfur dioxide oxidizes, produces tiny aerosol particles. And that these particles, they grow at exactly the size necessary to sort of reflect back part of the solar radiation. 

NEIL DEGRASSE TYSON: So they have— their size equals the wavelength of the visible light coming from the sun. 

DANIELE: Uh-huh. Yes, due to an interesting interplay of chemistry and microphysics and gravity and so on. If you let these particles grow, they grow exactly to sort of the submicron, alpha micron, one micron scale. That is exactly the wavelength of light, which makes— 

NEIL DEGRASSE TYSON: A micron’s a millionths of a meter. 

DANIELE: Uh-huh. A millionth of a meter. And it's exactly the wavelength of light, which makes them a perfect, or near perfect, scatterer of sunlight. 

NEIL DEGRASSE TYSON: So you call them aerosols. When we think of aerosols on Earth, we think of spray cans and things. Are we all thinking of the same definition? 

DANIELE: No, and that has been, curiously, a huge debate when it came to the COVID era, about what is an aerosol and what isn't. Normally, climate scientists think of aerosols as really just submicron particles, whether solid or liquid, that are suspended in air. But those are not particles that are really visible in the same way that larger droplets— what we call droplets— are. And the thing about aerosols is that their size is small enough that aerodynamically, they float in air much for much longer times than larger particles that we can actually see. 

NEIL DEGRASSE TYSON: Okay. So you said they float for longer, which means they do ultimately fall out. 

DANIELE: Yeah. 

NEIL DEGRASSE TYSON: So you have to, like, send up another batch. 

DANIELE: Uh-huh. Yeah. And the thing is, the way in which most aerosols get removed from the atmosphere is normally through rain out, wash out, as in, clouds raining on top of them and bringing these particles down to the ground. Fundamentally, in the stratosphere, we have observed out of things like volcanic eruptions that once these particles get released all the way to the stratosphere, they stay for much, much longer than they would close to the surface. 

NEIL DEGRASSE TYSON: Remind us, the stratosphere is above all the weather.

DANIELE: Yeah. We live close to the surface, but in what we call the troposphere, where there's turbulence and there's clouds and there's humidity. And on top of that, there's a much quieter part of the atmosphere, what we call the stratosphere, because it's very stratified. And things that end up there— which are not that many— hey end up staying there for quite a long time. But not forever. 

NEIL DEGRASSE TYSON: Good to know. Let me just remind people, while they are each professors at their respective institutions, they are speaking out of their own expertise and not for the institution itself. Just want to make that clear. So Howard, I'm delighted to know that someone such as you exists, who's thinking about removing the carbon dioxide from the atmosphere. That sounds like the obvious first thing to do. Or the second thing to do. Whereas this sounds a little more like science fiction here, that in any good science fiction story goes bad halfway through the storytelling. We know. So can you give us the top three best ways to take carbon dioxide out of the air? 

HOWARD: So there's a whole array of ways to do it, and basically you either can do it biologically or chemically. On the biological side, I think people maybe are familiar with planting trees. We've heard that. Afforestation, reforestation. 

NEIL DEGRASSE TYSON: So planting a tree, the tree absorbs the carbon dioxide from the air, and it's just in its own physical body.

HOWARD: Right. 

NEIL DEGRASSE TYSON: Okay. 

HOWARD: And of course, there's the permanence issue. You know, how long will it stay there? As we see, there's forest fires and things like that. So that's an issue with it. You can also harvest the trees and convert them into something. So, you can burn the trees at a power plant and capture the CO2 at the power plant and pump it into the ground. And so that— once again, the trees take it out of the atmosphere, and we capture the CO2 and put in the ground. So we're pulling it out of the atmosphere to the ground. 

NEIL DEGRASSE TYSON: So trees are CO2 concentration machines, if you will. Because otherwise, you're grabbing— what is the CO2 fraction of our atmosphere? It's very low, half of 1% or something? 

HOWARD: 420 ppm. Point-zero-four percent. Point-zero-four percent.

NEIL DEGRASSE TYSON: Oh, I was off by a factor of 10. Yeah, good. Okay. So. But a tree gathers it all, and now you do what you just described.

HOWARD: Right. 

NEIL DEGRASSE TYSON: And you've got it at the source.

HOWARD: And if you do it chemically, it takes a lot of energy. The nice thing about biologically, the energy comes from the sun through photosynthesis, so you don't have to add any energy to that. If you do— one of the big methods doing it chemically is something called direct air capture. And think of a air purifier in your house, but these are on a much bigger scale. And you blow air through these systems, and they take out the CO2. Once again, you capture it, and you can put it underground. 

NEIL DEGRASSE TYSON: Ideally, you would do that near the highest concentration CO2-producing places. 

HOWARD: No— well, no. You do this out of the air. 

NEIL DEGRASSE TYSON: Just out in open air. 

HOWARD: Yeah. And because it's only 420 ppm in the air, it's a lot more difficult than doing it, say, at a power plant, where it may be 10% in the air. 

NEIL DEGRASSE TYSON: Right, exactly. That's all I was saying, right. Okay, so ppm, parts per million.

HOWARD: Parts per million.

NEIL DEGRASSE TYSON: Yeah, yeah. 

HOWARD: So, yeah. 

NEIL DEGRASSE TYSON: All right. So tell me about the plankton solution because that was new to me. The plankton solution to this. The plankton are absorbing carbon dioxide? The phytoplankton? 

HOWARD: Oh, in the ocean? 

NEIL DEGRASSE TYSON: Yeah. 

HOWARD: Okay. Well, I mean, in the ocean— the ocean is a big sink of carbon right now. In fact, about half the CO2 we put in the atmosphere ends up in the ocean. And over time, 80% of the CO2 we put up today will end up in the ocean. There's two ways—well, the way that it works is, the surface layer of the ocean is pretty much at equilibrium with the atmosphere on a time scale of, say, a few months. So as the CO2 goes up in the atmosphere, it goes up in the surface ocean. However, to get it from the surface ocean to the deep ocean, where the bulk of the storage is, takes centuries. So that's a slow process. And a lot of that's done with what's called a salinity pump, where you have sinking currents in, like—

NEIL DEGRASSE TYSON: So I thought— there's no life form that does it at the surface and sinks? 

HOWARD: Yeah. Well— yeah. And then there’s something called a biological pump. 

NEIL DEGRASSE TYSON: Right. That's all— 

HOWARD: What you’re talking about. And there's where you you get the phytoplankton. They die and they sink. But most of the phytoplankton that dies and sinks do not get to the deep ocean. But it gets what they call remineralized. It gets basically turned back into CO2. So both of those mechanisms are way to get into the deep ocean that you have there. But it's really the inorganic cycle in the ocean. And when it's in the ocean, it's not in the form of CO2, but it's in the form of bicarbonate ions. About 85% of the carbon in the ocean is informed by carbonate ions. And because the CO2 has this chemistry in the ocean— it's like 30 times more soluble than, say, oxygen, will be the ocean. And that's why it's such a good sink of carbon dioxide. 

NEIL DEGRASSE TYSON: It's a sink. But if we reduce the CO2 in the air, that pulls it out of the ocean. So the ocean is this—it's like a spigot, 

HOWARD: Well, because of the time thing—so if we stopped, today, all CO2 emissions into the atmosphere— magically do that— the ocean will still absorb CO2 from the atmosphere for a few centuries. Of course, the rate that it absorbs will continually go down until the ocean, the whole ocean, hits equilibrium with the atmosphere. Then after that, you start pulling it down for the atmosphere then you can see degassing from the ocean. 

NEIL DEGRASSE TYSON: I didn't know there was that time delay, because the whole ocean would need to go into equilibrium for that to happen. Dustin. So, you have a PhD in chemical engineering? 

DUSTIN: No, environmental studies. A BS in chemical engineering.

NEIL DEGRASSE TYSON: A BS in chemical engineering, and a PhD in environmental studies, yes. So with that profile, what do you see are the paths forward for society, for our growing energy needs?

DUSTIN: Well, I think—

NEIL DEGRASSE TYSON: Because the energy needs are not going to slow down. 

DUSTIN: Yeah. 

NEIL DEGRASSE TYSON: Everything we read about what we need to sustain AI. 

DUSTIN: Yep. 

NEIL DEGRASSE TYSON: What else? Other computing farms. 

DUSTIN: Data science, all that. 

NEIL DEGRASSE TYSON: Bitcoin mining, that sort of thing. Yes. 

DUSTIN: Or Bitcoin scams. Yeah. So when I first started teaching my energy and environment class 15 years ago, wind energy was 1% of US supply and solar was 0.1%, and coal was 42%. And last year, solar and wind combined to match coal power. [APPLAUSE] By 2032, solar power alone is going to top all coal-fired generation in the world. 

NEIL DEGRASSE TYSON: Solar power alone.

DUSTIN: Alone. 

NEIL DEGRASSE TYSON: Is that that because— 

DUSTIN: That's seven years from now. 

NEIL DEGRASSE TYSON: —because it's gotten cheaper to invoke?

DUSTIN: It’s gotten a lot cheaper. So I think the fastest path to decarbonization is to deploy renewable energy. And we need to do it in a targeted way. And it has to begin with trying to retire all of the fossil fuel power plants in the world. 

NEIL DEGRASSE TYSON: Yeah, but you can't do that. [APPLAUSE]

DANIELE: You're kind of popular, aren’t you?

NEIL DEGRASSE TYSON: You've just gotten three applause.

DUSTIN: It’s the most popular technology in the world, Neil.

NEIL DEGRASSE TYSON: But, yeah. You can only say that because solar energy is getting cheaper, so obviously people are going to go for the cheap solution. They don't otherwise care what comes out of their wall faucet, if it was made by coal or by wind or solar panels. So this is not by changing people's hearts, is it? It's by changing the economic landscape on which a person makes a decision.

DUSTIN: It's changing the economic landscape, but it's also considering many of the other impacts. So the geoengineering conversation is obviously a conversation about tackling climate change. But we have air pollution that kills millions of people. We have fly ash ponds outside of coal fire power plants that often break open and flood communities in toxic poisons. So we have a lot of environmental impacts from our conventional energy technologies that aren't part of the calculus of making energy cheap. So we have to both deploy more renewable energy, but we also start to adding costs to the conventional sources.

NEIL DEGRASSE TYSON: Thank you. Beth, you have a PhD in international relations.

BETH: Yes.

NEIL DEGRASSE TYSON: And you also coined the term, I have here, “environmental terrorism”. Could you comment on what you meant by that in your published works?

BETH: What I meant by environmental terrorism— I’d been looking at climate change and security for a few years while I worked on a think tank in the West Coast. And it occurred to me that if a terrorist really wanted to do do damage to a country, if they really wanted to affect its government, its population, strike terror into people, and then get them to change some policy or some some operation, that the way to do it isn't to fly planes into buildings. Not a lasting change, okay? I'm trying to put my terrorist hat on here. Like I have a terrorist hat. And the way to do it would be to attack their natural resources. So you would set forest fires, you would blow up infrastructure, you might ruin their ecosystem, if you had that ability. And this is what I meant by environmental terrorism. The environment could be a target of terror, or it could be a tool of terror.

NEIL DEGRASSE TYSON: Maybe the terrorists are not that educated to know how to do that.

BETH: Well, if they read my article. [LAUGHTER]

NEIL DEGRASSE TYSON: Oh! Oh! Oh, so whatever solutions may come out of this conversation, it becomes a security risk, basically, as a target.

BETH: It might become a target security risk. It depends on what method of geoengineering is being used. Geoengineering, as we all know on this panel here, this is a huge umbrella term that covers lots of different kinds of technologies, some of which are not problematic, particularly from a security point of view. Others very well might be. And so if I'm an enterprising terrorist—  boy, I'm just digging a hole here. If I'm an enterprising terrorist, I'm going to look very carefully at what kind of technologies are being deployed and how I could affect that to my own advantage.

NEIL DEGRASSE TYSON: Watch out, you could get deported.

BETH: I’m from Chicago.

NEIL DEGRASSE TYSON: Holly Jean Buck, your PhD is in sociology, one of my favorite fields. A field of my father's, I will say. He was active in the civil rights movement. So I have a sensitivity to help people think and feel about the world, about science, about technology. And— as do you. So I'm delighted to have you on the panel. And, what do you see in this conversation? What do you see might be social barriers to its enactment? Do people often vote for something that they don't understand, they were just told it'll solve your problem? How do people— [LAUGHTER]. Take us through the interface between human conduct and societal solutions that are presented to them.

HOLLY JEAN: So that's a huge question, But I'll say two things. One is that we have a bunch of technologies that we started to adopt without really thinking about it. And I would put the smartphone and social media and things like that in that category, where we just got used to them. Everybody thought they were great at first, and now we're asking questions. Same thing with some of the chemicals— PFAs, you've heard of. These sorts of things have unintended consequences. 

NEIL DEGRASSE TYSON: Those are the those are the forever chemicals?

HOLLY JEAN: Yeah.

NEIL DEGRASSE TYSON: Yes.

HOLLY JEAN: Yeah. And so people are looking at different examples, thinking, “Well, that didn't go so great for us. Maybe we need to take a different approach to how we think about adopting and making decisions on new technologies.”

NEIL DEGRASSE TYSON: Yeah, but nobody at the dawn of the smartphone is thinking, “One day it'll create personal image problems,” or that it would be the greatest source of misinformation ever conceived. How— could we have seen that?

HOLLY JEAN: That's the interesting thing about this topic, and part of why I work on it, is because a lot of the people who are the scientists are actually asking these questions at the outset. And hopefully they can continue to have the primary place in this conversation. 

NEIL DEGRASSE TYSON: But the examples you give from the past are where we did not see the outcome coming.

HOLLY JEAN: Exactly.

NEIL DEGRASSE TYSON: So that doesn't bode well for the future. [CROWD RESPONSE] Okay, stop. Just saying, Kevin, you have a PhD in geography. Okay. What's the capital of— [LAUGHTER].

KEVIN: Not geography.

NEIL DEGRASSE TYSON: Not geography— geographers don't learn that? That's not a thing?

KEVIN: It is technically geography.

NEIL DEGRASSE TYSON: Okay, capital of Upper Volta.

KEVIN: Oh, no, no, no.

NEIL DEGRASSE TYSON: Yeah.

BETH: Upper Volta doesn't exist anymore.

NEIL DEGRASSE TYSON: Oh, it doesn't exist anymore?

KEVIN: You'd know that. [APPLAUSE]

NEIL DEGRASSE TYSON: At the time I learned what the capital was of Upper Volta. It was Ouagadougou. And I thought that was really cool. Out of date information now. So with a PhD in geography, it might uniquely qualify you to comment on the global consequences of this conversation, and how it can affect different places in the world, their climate. Will everyone improve it the same way? Are there differences from one place to another? And do we need to be thinking about this?

KEVIN: Yes, we do need to be thinking about it. And I don't know if a PhD in geography makes me uniquely— actually, it does— I don't know what other people are even doing on this panel. I'm uniquely qualified to talk about this. Yeah, so geography, it's not state capitals and all of that. It's a broad discipline that, if it has any unifying center, it's a focus on human-environment relations and how they emerge and are interlinked across scales in various ways. And within that broad field, I am— my subfield is political geography. And more specifically, political economy of the environment, which means I think about the ways that capitalism is our dominant economic mode. Both drives environmental problems and constrains our ability to respond to them.

And in terms of geoengineering, I think— solar geoengineering, specifically— there are a lot of really important questions as to who's going to be— what are the environmental effects of this? Who's going to be impacted? Is it going to be uneven and unequal? It will. We have to compare that with climate change. But my primary concern—

NEIL DEGRASSE TYSON: What you mean is, whatever the drawbacks are of solar geoengineering—

KEVIN: Yeah.

NEIL DEGRASSE TYSON: There'll be pluses and minuses. There are already sort of pluses and minuses to other things going on here now.

KEVIN: Certainly.

NEIL DEGRASSE TYSON: So it's an exercise in relative risk factors.

KEVIN: Absolutely. Yeah.

NEIL DEGRASSE TYSON: Is that a fair characterization? Yeah. We wouldn't be having this conversation about solar geoengineering if climate change didn't present massive risks that we have to deal with as immediately as possible. But that's actually my central problem with a lot of these technologies, is that I worry that, you know, we live in an era of where corporations and billionaires have massive power. Where geopolitical contestation is on the rise. Where countries are rearming, and authoritarianism and fascism is eroding the old order. And so a technology that could potentially give the fossil fuel industry— the wealthy and powerful, more broadly— the ability to deal with the climate crisis without cutting emissions, right, or at least slowing down efforts to cut emissions, is deeply troubling. And I really can't see— I find it impossible, in those conditions that I just laid out to, see any other way for this technology to unfold, other than being a tool of the powerful to maintain the world for them. [APPLAUSE] 

NEIL DEGRASSE TYSON: Howard, if you figure out how to remove CO2, then what's to stop— either politically, culturally, economically— what's to stop oil companies from continuing to drill, baby, drill? If you have a way to remove the CO2, there is no harm, is there, in burning more fossil fuels? Like, what do you care at that point?

HOWARD: So, it's really a magnitude of scale. So yes, we can remove some CO2. And I think if we're really going to hit net zero, it's going to be essential that we move CO2, because we're never going to be able to stop all of our greenhouse gas emissions. Some things are going to be very expensive, like flying airplanes without jet fuel. It may be cheaper to offset it by removing CO2 from the atmosphere. We have a lot of greenhouse gasses.

NEIL DEGRASSE TYSON: Just so we're on the same page here, if the rule is net zero, it means you can produce CO2, but somewhere else in the equation of your business model, you have to be removing it, correct?

HOWARD: Right. So net zero means you're removing as much as you're emitting. But there's also greenhouse gas emissions from agriculture, whether it's belching cows, methane, or N2O coming off from fertilizer use. So you are going to need some of it. But it's the scale. I mean, to use your— no matter what, I think when we hit net zero, you're going to be using a lot less fossil fuels than you use today. And some people think, if you look at the models they project, “Well, we may need 10 to 20 billion tons of CO2 removed a year.” So the world puts out about 40 billion tons, and maybe another 10 billion tons of equivalent in greenhouse gasses. So 10 to 20 billion tons is a lot. And my analysis is we're going to fall short of that. So you're not going to be able to burn fossil fuels willy nilly. We're going to need to reduce our fossil fuels drastically and use carbon removal to get us that last 10, 20, maybe 30%, to net zero.

NEIL DEGRASSE TYSON: Dustin, what spooks you most about all this? You got three applause the last time, let’s see if we get you a fourth one.

DUSTIN: Well, I feel like even the climate problem has reduced the challenge to just being a one- dimensional problem about carbon. About carbon dioxide. And I worry about ecological consequences. I worry about communities not being able to speak for themselves or speak for places that they think are important.

NEIL DEGRASSE TYSON: Or to have a place at the table.

DUSTIN: Yeah.

NEIL DEGRASSE TYSON: When decisions are getting made.

DUSTIN: Yeah. I think that we have to have— if there are efforts to do geoengineering— but I think even broadly, if you're talking about wind power or solar power— having public participation. Having tribal consultation here in the US context. These are going to be crucial.

NEIL DEGRASSE TYSON: You’re talking about native peoples.

DUSTIN: Uh-huh. Yeah.

NEIL DEGRASSE TYSON: Yes, uh-huh. Daniele.

HOWARD: Can I just—

NEIL DEGRASSE TYSON: Yeah, butt in.

HOWARD: I think there’s a misconception out there, that  renewables can do it by themselves. And there's no one technology. So electricity, what, maybe 30% of our energy use today. And really, wind and solar getting above 60% maybe 70% if you're lucky, is about the best you can do, because they're intermittent. And you really need— for our society today, you need 24/7. You need high reliability. You need 99.999 percent.

NEIL DEGRASSE TYSON: But Howard, you're avoiding the obvious other N-word in the room, nuclear.

HOWARD: Yes.

NEIL DEGRASSE TYSON: Okay? One of the two N-words you're not supposed to use. Holly, what do you feel about nuclear? How do people feel about nuclear? It's portable— not portable. But you can make local plants, and it doesn't depend on the sun, and you make as much as you want at any given moment. You've thought about nuclear?

HOLLY: Yeah, I thought about nuclear because I wrote a book about ending fossil fuels, and I had to take a deep dive into how the energy system works, Dustin's area of expertise. And I came to the conclusion that we need nuclear, geothermal, other clean therm. People are concerned about nuclear because of a sense of dread because it was associated with nuclear weapons back in the day. But we've really seen, since—

NEIL DEGRASSE TYSON: And today.

HOLLY: Well, let’s not go there yet.

NEIL DEGRASSE TYSON: Back in the day and today. Yeah. Nuclear weapons.

HOLLY: Yeah. Sentiment has shifted a bit, and we need a lot more investment in it.

NEIL DEGRASSE TYSON: Do you think the economics will make people more comfortable with nuclear options here? The economics that is, if everything else is really expensive and nuclear power plants— France has been using nuclear power for decades.

HOLLY: Yeah. No, the Department of Energy did a report called “The Nuclear Liftoff”, and they found that the system costs, if you add in nuclear with renewable and solar, it could lower the cost 37%. So it could be— help the affordability of the whole transition.

NEIL DEGRASSE TYSON: So Daniele, the confidence you have in your models— because it spooks so many of us. Dustin especially, perhaps. But also, Beth is just concerned how this will play out internationally. Does the confidence in your models come from just because you just make badass models? Or do you have some other reference frame to give you confidence?

DANIELE: I mean, I do make badass models. [LAUGHTER] But the whole job of a climate scientist is trying to understand the system and finding natural examples to allow us to understand whether we're actually understanding the system as well as we think. For instance, when it comes to climate change, Arrhenius, back in the 19th century, had already guessed that increasing CO2 concentration would warm the planet. That is really not nuclear science. 

NEIL DEGRASSE TYSON: So that was like, early climate science modeling. And tell me the name of the scientist again.

DANIELE: Arrhenius.

NEIL DEGRASSE TYSON: Arrhenius.

DANIELE: One of the first, most famous chemists in the world. He already guessed that, you know, CO2 traps, along with energy. The planet, like every other—

NEIL DEGRASSE TYSON: That would be infrared.

DANIELE: Infrared radiation. And the more CO2 you add, the more you add to the greenhouse effect. And— but in a way, we did not have an actual physical proof of that until we started seeing temperatures warm, until we sent satellites up in the atmosphere and we could measure energy in versus energy out and actually see this gap growing. Now, we can see this gap growing. And so in that way, we know that climate change is happening.

NEIL DEGRASSE TYSON: What about volcanos?

DANIELE: Right. And the same way, we've known for a long while— there were hypotheses of the fact that large volcanic eruptions could cool the climate. Benjamin Franklin actually hypothesized that was something that happened after the Tambora eruption in 1815. And for a long time—

NEIL DEGRASSE TYSON: Tambora in Indonesia, I think, yeah?

DANIELE: Yes. Yes. And during the 20th century, there were multiple of these large volcanic eruptions, the last one being Mount Pinatubo erupting in 1991. After which— after this eruption, Jim Hansen, one of the greatest climate scientists of our time, said in one of the first papers after Pinatubo, “This is going to be the acid test for climate models.” If we predict, as we are—

NEIL DEGRASSE TYSON: You mentioned Jim Hansen.

DANIELE: Yes?

NEIL DEGRASSE TYSON: Yes. Of NASA— he’s right up the street here.

DANIELE: Yes indeed.

NEIL DEGRASSE TYSON: He’s right up the street here.

DANIELE: Uh-huh. And really, the greatest—one of the greatest climate scientists in the world. And right after Pinatubo, he said our climate models, once we add these aerosols that are coming from Pinatubo to our climate models, our climate models project that the planet will cool by even up to half a degree. And so—

NEIL DEGRASSE TYSON: By how much?

DANIELE: Half a degree Celsius.

NEIL DEGRASSE TYSON: Oh, half a degree.

DANIELE: Yes. And so if our models turn out to be right, that's going to be the acid test—that's how we called it—  of our understanding of climate. And indeed, we did observe a strong cooling after the Pinatubo eruption. And what this Pinatubo volcano did, it threw in the atmosphere, in the stratosphere, millions of tons of sulfur dioxide. Roughly 20 million tons of sulfur dioxide. And diesel for dioxide produced the aerosols, cooled the planet. And we saw that. And after two years, the aerosols were gone. Removed from the stratosphere.

NEIL DEGRASSE TYSON: These are the aerosols you want to put in the atmosphere to do the solar geoengineering.

DANIELE: These are the aerosols that are being studied in our climate models—

NEIL DEGRASSE TYSON: Okay— [LAUGHTER]. 

DANIELE: — to figure out whether they will cool the planet. Yes. But not the ones I want to put.

NEIL DEGRASSE TYSON: You still haven’t gotten an applause from the audience.

DANIELE: I'm sorry. [LAUGHTER] That's cheating.

NEIL DEGRASSE TYSON: Beth, it's not just his models. He has data from nature doing exactly what it is he intends to do, and they see the consequences. They see the fallout. So why doesn't that give you some— is the word security? Some comfort that the ideas are in the right direction.

BETH: Because nobody can blame nature. Nobody made that volcano go off. It went off on its own. But if nations actually try to start putting this stuff up into the atmosphere on purpose, now you have some states who are going to benefit by this. Other states may not benefit by this. It's going to take an extraordinarily long period of time— decades, maybe— to see the effects that we want. And this opens up the political arena for a lot of misunderstandings and— security calculations. I'll put it that way. 

NEIL DEGRASSE TYSON: Could this be because the whole world isn't educated to the same level to have a common conversation about the need or the cause or the effects of this?

BETH: No, I think they can have a common conversation about this. But what we're not recognizing in this attempt to adapt a planet-changing technology—

NEIL DEGRASSE TYSON: Yeah?

BETH: That's what it is. If it's not planet changing, it's not doing its job.

NEIL DEGRASSE TYSON: Right.

BETH: So it better be changing the planet, or it's pointless. It's just random pollution. But this is a planet-changing technology. And we need to think about how states would react to this with their own interests in mind. Climate change is going to break international relations as we know it, because we have the whole system based on the idea of sovereignty. Security comes from sovereignty, meaning you control your own territory. Your borders are inviolable.

NEIL DEGRASSE TYSON: But you don't control your own air.

BETH: No, you don't, but we don't recognize this yet. States don't recognize this. And as a result, they are making decisions to participate in treaties or not participate in treaties, to withdraw from treaties, to ignore them, to do side deals for oil at the cost— 

NEIL DEGRASSE TYSON: We had a good treaty in the ‘80s or ‘90s. There was the Montreal Protocol.

BETH: Nineteen-eighty-five, yes.

NEIL DEGRASSE TYSON: Yeah. ’89?

BETH: Eighty-seven. Sorry, my bad, seven. Yeah.

NEIL DEGRASSE TYSON: Eighty-seven. Where everyone got together and agreed that we want to protect the ozone of the atmosphere. And if memory serves, that had more signatures, more countries signing it than any other treaty ever. So that's an existence proof, as we'll say in mathematics—

BETH: Right.

NEIL DEGRASSE TYSON: — that it's possible for the whole world to get together with a common goal. 

BETH: It’s possible. At this point in time, it's unlikely. And let me make a distinction between what we're trying to address with the Montreal Protocol, and any kind of climate treaty. There were just a—

NEIL DEGRASSE TYSON: You have to be a little optimistic at some point.

BETH: I'm trying to get there. I’m trying to get there.

NEIL DEGRASSE TYSON: At some point, we can—

BETH: I'm trying to get there.

NEIL DEGRASSE TYSON: Okay.

BETH: This was a materially different regime, right? There were a few chemicals that were being looked at, CFCs and others. There were only a few companies in a few countries that produced this. We only used them in a few applications, and there were already a substitute lined up. So now—

NEIL DEGRASSE TYSON: You’re saying— CFC is the chlorofluorocarbons.

BETH: Right.

NEIL DEGRASSE TYSON: Right.

BETH: CFCs. And HFCs the hydrofluorocarbons— which turned out to be a greenhouse gas, oops— that we put used in substitutes were already ready. So now we look at climate treaty, and we'll say, “We'll just use the same structure.” But good god, this problem is exponentially bigger now. Every country in the world is either producing or using— or both— fossil fuels. It underpins the entire global economy, and now we have to try to get everybody on board and basically say to them, “You need to reduce your carbon emissions, irrespective of the state of development you're in.” States are not going to sign onto this.

NEIL DEGRASSE TYSON: There's a scientist in my department, a visiting scientist from Sweden. And I said, “We're about to do this panel.” And she said, “You know, if the world gets a little warmer, that's okay with the Swedes.”

BETH: And that’s okay with the Russians.

NEIL DEGRASSE TYSON: Right? So it's only bad for the people for whom it's bad. And if you're going to say, “Let's fix us,” and then you make it worse for somebody else, that's—

BETH: That sounds inhumane, but that might be a rational security calculation for a particular state, which would incentivize them to develop this kind of technology further.

NEIL DEGRASSE TYSON: Kevin, where are you on this?

KEVIN: Well. A lot of places. I think what might— 

NEIL DEGRASSE TYSON: [LAUGHTER] Pick one of those places and share it. Yeah.

KEVIN: Sure.

BETH: Dig your way out of that one.

KEVIN: As Beth was talking earlier, I— what always helps me think about this is thinking about— not in the abstract, but going off of the models that we have. And Dan might be able to correct me on this, or fill in some of the— any of my errors. But some of the modeling that's been done in terms of what it would require to literally change the planet, right, is in a moderate scenario of, like, 15 years. Which, given the fact that we're not cutting emissions fast enough, we're going to have to do something like solar geoengineering for much longer than that, right? There's work that's been done that suggests that we're going to have to have continually flying aircraft— which don't exist, we don't have the aircraft that can go high enough with a big enough payload— from multiple different bases, placed across the planet. Sixty-one thousand flights a year for many decades, right? So we're going to have a huge intervention of aircraft continually spraying sulfur dioxide, or whatever chemical compounds that they come up with that works.

NEIL DEGRASSE TYSON: You're saying that's what it would take.

KEVIN: Yeah. And that’s in a moderate scenario.

NEIL DEGRASSE TYSON: Today, the aircraft are not flying in the stratosphere. So how is this deposit of aerosols getting the stratosphere where you need them?

DANIELE: Say again? I could not hear from you, couldn't here. 

NEIL DEGRASSE TYSON: So he’s saying, to deploy this these aerosols would require this network of airplanes flying high, releasing these aerosols continually, to achieve the ends sought. But if airplanes fly in the troposphere, and you need the aerosols in the stratosphere—

DANIELE: Yes.

NEIL DEGRASSE TYSON: Tell us stratosphere in Italian.

DANIELE: Stratosfera.

NEIL DEGRASSE TYSON: Yeah. Love it. Love it.

DANIELE: You got me there.

NEIL DEGRASSE TYSON: Stratosfera. How do you get this up into the stratosphere?

DANIELE: Yeah. I think Kevin does make a good point. Fundamentally—and this, in a way, one could say it's a positive thing. We are not currently doing solar geoengineering, because we can't. Because nobody has been, in a way, interested enough to develop the technology.

NEIL DEGRASSE TYSON: Meanwhile, people have been thinking about this for 30 years.

DANIELE: Yeah, they have. So indeed, there are clearly obstacles that are not just physical in nature. This is not just about trusting or believing in models. This is clearly about a much more complex societal problem. I agree with Kevin. Nobody has done it yet, but people are thinking about it, right? Fundamentally, you would need to go all the way up to the stratosphere to avoid these aerosols falling very fast. But currently, there is no other way to— no other reason to go to the stratosphere. So nobody has developed a technology yet.

NEIL DEGRASSE TYSON: Okay. So everything you said, no one can act on right now.

DANIELE: No, they can't. Plus, the moment—

NEIL DEGRASSE TYSON: Why did I put you on the panel?

DANIELE: I've been asking myself this question since yesterday. But you know what? I'm here, so too late. [LAUGHTER] But the fact that you could do something, hypothetically, is enough, indeed. Because this is such a wicked problem, countries are thinking, what if another country does it? How would I be able to tell? Indeed, how would I be able to verify whether a country does it? And says, “No, no, it's all good. I'm not arming your citizens in any way.” That is fundamentally, really the largest problem. 

NEIL DEGRASSE TYSON: Yeah. But of course, as Carl Sagan famously noted, air molecules do not carry passports. So whatever rule you put over the airspace of your country is not— that's kind of pointless, given the overall circulation of air on our planet. But let me get back— I'm still moved by what Beth said about your absence of confidence in a treaty that the whole world can agree on once again. Holly, what does it take to get diverse societies to agree? You're a sociologist. Give me an answer to that.

HOLLY: Well, I wanted to push—

NEIL DEGRASSE TYSON: I should ask just to clarify, as a sociologist, do you just study what people do and how they behave, or do you study ways to influence that behavior and what they do?

HOLLY: I study the stories they tell themselves about what they're doing. So like with your Swedish colleague, actually, I found something quite different in my research when I was doing research in the northern part of Finland. People there were really concerned about what would happen in other parts of the globe. Because they're well educated. They understood that it would impact them through migration, through global economic impacts. And I think once people have that understanding of how entangled we all are, there's a shared basis for a discussion.

NEIL DEGRASSE TYSON: Interesting. And that's a that's a level of enlightenment that not everyone carries. Is what— not to put words in your mouth, but I think that's what you're saying.

HOLLY: In a way. They also have a much higher trust in government and just more social cohesion.

NEIL DEGRASSE TYSON: They trust their government? [LAUGHTER]

HOLLY: More or less. But I think it's an example, that, you know, we could do that. We could get there. And I also want to say that I think this field that Beth works in, it has a lot of insight. But I think people who approach it from an international relations standpoint, they tend to see the conflict everywhere. And I also think there's opportunities for peace building, for new forms of cooperation from this topic and this crisis.

NEIL DEGRASSE TYSON:Beth does not sound like that person.

BETH: I hope you’re right. I mean, honestly, I'm not looking forward to any kind of conflict on this. I just predict that there will be.

NEIL DEGRASSE TYSON: Yeah.

BETH: Because you said, could they see how they're all entwined? But that's precisely what our system of sovereignty does not permit us to see. So states don't see themselves as entwined. I mean, look some of our recent governmental decisions here. We don't see ourselves as entwined with anybody, even though, in fact, we are. So I like where you're going with this. I do. I just think it's going to take a long time to get there, and I don't know if we have that much time.

NEIL DEGRASSE TYSON: Dustin, what did we learn from COVID, when for a while, no one was flying airplanes. We weren't going anywhere. So the atmosphere changed over that time. Are there lessons to be learned from that, good or bad?

DUSTIN: Well, I can't speak directly to the atmosphere change part, but we did see disruptions in energy production. We saw disruptions in supply chains. Anybody have a problem getting something during that time, right? I think you've all experienced that. And you know, from that experience, I think we realized that our energy systems and our economy was very vulnerable. We had built a system of just-in-time production to get things produced without much delay delivering—

NEIL DEGRASSE TYSON: Which, by the way, was a major economic point of brilliance, when you're not wasting inventory in a warehouse—

DUSTIN: Exactly.

NEIL DEGRASSE TYSON: — hoping someone buys it, right?

DUSTIN:  Uh-huh. And then you run out of toilet paper, and everybody understands how important inventory actually is sometimes. So.

NEIL DEGRASSE TYSON: Because of the toilet paper. Yeah, okay. 

DUSTIN: Something that everybody can relate. 

NEIL DEGRASSE TYSON: I have friends that still have a closet full of toilet paper, and it's a little scary, actually.

DUSTIN: But I think the lessons learned are we need more resilient infrastructures. We need more resilient supply chains, and we need more resilient economies to go through challenges like that. And if we end up in a climate crisis situation, that could happen again.

NEIL DEGRASSE TYSON: So you're just saying that. Is anyone doing that now, now that we've learned from COVID? 

DUSTIN: Oh, I'm sure that everybody— I mean, I'm thinking, like— I study, you know, the battery life cycle, and study battery manufacturers. And they're thinking about these things all the time. Because we saw, not only with COVID, with the war in Ukraine. You know, we see how important it is to have resilience in production systems.

NEIL DEGRASSE TYSON: What I find interesting is— I don't remember how I ended up on this list, but I'm on a list that receives ad solicitations for survivalist— yeah. Yeah. I think I bought something from a website at some point. And what's curious to me is a big selling item among a survivalist is a solar- powered generator. And I thought that's kind of cool. We have survivalists using solar power. That's— that's good.

DUSTIN: Yeah.

NEIL DEGRASSE TYSON: It's a small thing. 

DUSTIN: It's very small. It could be part of it, though. I mean, I think— you know more— you know, in California, we have a lot of blackouts because of wildfires sometimes. And, I mean, that’s example of like having a system breakdown that we all depend on, right? We all depend on—and, you know, lessons learned from that are decentralizing some of our energy systems. More smart grids. That helps make more redundancy in electricity delivery.

NEIL DEGRASSE TYSON: Didn't Canada threaten to to shut off some of the Northeast power? How much of that our power do they supply? 

DUSTIN: I'm not as familiar with the Northeast. Maybe Holly could speak to that one. But I know that you have to think of North America in general, both the pipeline systems that carry natural gas, and the electricity grid, as completely integrated. So.

NEIL DEGRASSE TYSON: Okay. Yeah. Don't so fully integrate that we need a 51st state to— yeah.

DUSTIN: Yeah, tariffs aren't going to help.

NEIL DEGRASSE TYSON: Yeah. Howard, your plans to remove CO2. That's not the only greenhouse gas, as we know. Of course there's methane. As— which one of you referenced cow burps? Yes, okay. How do you get methane out of the air relative to carbon dioxide?

HOWARD: Well, methane, the concentration of methane in the atmosphere is about 200 times less than CO2. So some people— there's always people looking at, can we do this?

NEIL DEGRASSE TYSON: I have a number in my head, but it's— is it the number 16 or something— times more potent a greenhouse gas than CO2 is?

HOWARD: So— yes. So, per molecule, methane is a more potent greenhouse gas. But its lifetime in the atmosphere is less. So they have this thing called “global warming potential” that compares the CO2 equivalent of these different greenhouse gasses. So one thing that complicates this is, if you use a 20-year greenhouse warming potential, the number is bigger for methane than, say, if you use 100 years. And so it's like talking about a discount rate in economics. Whichever one you use can have a big difference. I forget the exact number. What's it, 830, 2030, something like that?

DUSTIN: The number for what?

HOWARD: The greenhouse warming potential of methane.

DUSTIN: It’s 25 on 100 years, and I think it's 80 or 70,80, on a 20-year.

NEIL DEGRASSE TYSON: It’s a relative time. So methane would just combine with some other chemical or something.

HOWARD: Yeah. But about two-thirds of the climate forcing comes from CO2. And I forget the exact— methane’s—I forget exactly, 20% or something like that.

NEIL DEGRASSE TYSON: And what's the biggest methane source? It can't be only cows, if we're also losing permafrost and we have organic matter thawing, and then releasing—

HOWARD: Yeah. So, that’s— so there's something with the climate science that people sort of use the word “tipping points”. That we go to a point that we start getting irreversible changes, or dramatic changes. And one of it is if our permafrost melts, which has a lot of methane stored in it. Will that start degassing methane? And there's no definitive answer on if or when that would happen, and how bad it would be. The mechanisms aren't totally understood. But right now, there's a debate whether the Arctic, the tundra, the permafrost up there, is a carbon sink or carbon source. There's always been a carbon sink, but it looks like it may start to become a carbon source now.

NEIL DEGRASSE TYSON: For greenhouse gas.

HOWARD: For greenhouse gasses. And will that accelerate in the future, and will that become a tipping point?

NEIL DEGRASSE TYSON: Beth, what did you— in your writings, you talk about Arctic security. You just mentioned what was going on in the Arctic, the melting of the glaciers. What do you mean by Arctic security?

BETH: Well, the Arctic could be a fascinating bellwether for how we're going to adapt to a globally warmed world. Because the Arctic used to be just a big frozen lake with some water on the edges, surrounded by countries. But it's increasingly losing its ice cap. The sea levels are rising, and you're going to end up with sort of the new Mediterranean at the top of the planet.

NEIL DEGRASSE TYSON: By the way, I was very disturbed when I was eight or nine, to learn that Santa Claus does not live on land.

BETH: No, he does not. But he will be speaking Russian soon.

NEIL DEGRASSE TYSON: Yeah, it's on his way, yeah.

BETH: Yeah.

NEIL DEGRASSE TYSON: But he's on an ice floe, and it might not be there, and he might be in a bathing suit pretty soon.

BETH: He might be relocating someplace else. Maybe to Canada, we don't know. But as the Arctic is thawing, you end up with new power relations between the Arctic countries. We have an organization called the Arctic Council, which assists with scientific cooperation and political negotiations and so on, about the Arctic. But its charter explicitly excludes security. So if there's more icebreakers that we need, if there's more ice cap submarines, if there's ocean transit going across the Arctic Ocean, through the northern sea route, or through the Northwest Passage, all this is going to have to be regulated in some way. Because if it's not regulated, then possession is nine-tenths of the law. And right now, that points to Russia pretty much owning it.

NEIL DEGRASSE TYSON: Why not Canada? Canada has these land masses that go pretty far north.

BETH: Well, I'll defer to my geographer colleague here, but the basin basically is deeper on the Canadian side, which means there's more long term ice there. The Russian side thaws first, is the gist of that. And so the Russians are already on this. They're building search and rescue stations, refueling stations. They're already charging boats tolls to break ice for them to take their cargo across the Arctic Ocean. So the Russians are thinking, “Global warming is working in our favor.” Which means that they're going to be operable up there in a way nobody else can be.

NEIL DEGRASSE TYSON: Isn’t there a treaty that governs—

BETH: Governs what? The ocean?

NEIL DEGRASSE TYSON: The oceans?

BETH: Yes, there is. The UN Convention on the Law of the Sea. Came into force, I think, in 1982. And Russia signed it, and Canada has signed it, and most of the countries around the world signed it. Guess which country has not signed it?

DUSTIN: Us.

BETH: That would be us. The United States has not signed it. We refused.

NEIL DEGRASSE TYSON: How do you spell us?

BETH: U-S.

NEIL DEGRASSE TYSON: The U.S. Okay.

BETH: USA number one? I don't know. But the reason we haven't signed it is because of sovereignty. The argument has been made in the Senate Foreign Relations Committee that this encroaches on our sovereignty. There's no need for us to sign it. We don't want anybody telling us what to do.

NEIL DEGRASSE TYSON: Holly, you authored a paper some years ago, which I just had no idea what it could mean. You're talking about gender and geoengineering. Could you explain what was going on in that paper?

HOLLY: Yeah. So this came from a finding in my master's research a very long time ago, where I counted who was making statements about geoengineering in the press. And at that time, 97% of the assertions were made by men. And I was thinking, what does it mean for men to basically be telling the story of what this even is?

NEIL DEGRASSE TYSON: Because we want to control everything. That's obvious, right?

HOLLY: Well, I wondered. But, I mean, we talked about a couple of different implications. One is, who gets to represent it? Who gets to say what it means? Who gets to set the agenda? But then there's another question of, is the science we're doing adequately recognizing impacts on women? On— you know. Not just— you can extend this critique beyond gender.

NEIL DEGRASSE TYSON: So just, people who don't have a seat at the table of who's making the decisions. It kind of comes down just to that, doesn't it?

HOLLY: Yeah. And so we made some recommendations about how we could maybe do the science differently.

NEIL DEGRASSE TYSON: Tell me about Africa. Most people don't know, on a globe— I don't know whether— because we're just deluded. But Africa can completely contain five continental United States.

KEVIN: Three and a half.

NEIL DEGRASSE TYSON: Three and a half?

KEVIN: Yeah.

NEIL DEGRASSE TYSON: What, do you have a degree in geography or something?

KEVIN: [LAUGHTER] I show that map in my intro geography classes all the time.

NEIL DEGRASSE TYSON: Yeah. So, how often is anyone talking about what African countries say about any of this?

KEVIN: African countries are certainly talking about it. And I, yeah, don't necessarily feel qualified to speak on their behalf. I can offer some observations. There's been—

NEIL DEGRASSE TYSON: You're not African?

KEVIN: I’m— no, no.

NEIL DEGRASSE TYSON: Yeah.

KEVIN: Yeah. And a lot of times— we were discussing earlier, these conversations unfold about people who are not present or at the table. And we need to be very cognizant of that. But it's a very contested topic. I'm slightly more familiar with those, you know, climate justice organizations from Africa that have taken a fairly strong stand against solar geoengineering. There have been those that have signed what's called a non-use agreement. There was a recent United Nations Environment meeting where a proposal was put forward, and a block of— I'm going to get this wrong, but I think 15 African countries forcefully opposed the parameters of the proposal put forward by the Swiss that was backed by Saudi Arabia and the United States and some other countries.

NEIL DEGRASSE TYSON: So what reasons were given to vote against it?

KEVIN: In that context, that it was lacking governance and perspectives outside the realm of science. So it was a very science-first approach that said we can kind of— “Let's do the research and figure out the ethical and political questions later.” And there was pushback against that.

NEIL DEGRASSE TYSON: So Holly, that's a repeating phenomenon, where you don't do the science first and then worry about the ethics later. You try to do it all at the same time. How realistic is that, going forward, for any new frontier of science?

HOLLY: I felt optimistic about it up until this point. Because we had—

NEIL DEGRASSE TYSON: Wait, up until right now? What did we do to you?

HOLLY: Up until, say, January. I don't know.

NEIL DEGRASSE TYSON: Okay.

HOLLY: Because that was the tenor of the conversation. We had this report from the US national academies that laid out a really integrated approach of doing governance, social science, all entwined.

NEIL DEGRASSE TYSON: On geoengineering?

HOLLY: Uh-huh. Yeah.

NEIL DEGRASSE TYSON: That was, like, 2021, was that report. Yes? Okay. I browsed that report, and it looked quite thorough to me. It's the National Academy of Sciences. So it's— you know, it's— you should pay attention to it. And in there was a whole section on cautions, and how to step softly in certain directions versus others, where our uncertainties are. And that seemed to me okay. But Kevin, you published a paper criticizing that report.

KEVIN: Yes.

NEIL DEGRASSE TYSON: It had, like, 40 climate scientists as signatures on it.

KEVIN: Right. Okay. So.

NEIL DEGRASSE TYSON: So what do you know that they don't know?

KEVIN: My colleagues and I— yeah. We took issue with that report for a number of reasons, from— you know, it was mostly physical scientists and economists, right? There was very little representation from humanities, social sciences. Very little representation from civil society, grassroots climate justice organizations, the Global South more broadly. But more than representation, which to me is secondary in this case, we felt it was a political intervention and not an objective scientific report. It was pushed by certain members within the geoengineering community, timed to kind of stoke this conversation within the Biden administration, which we saw happen. Members of Congress pushed the White House to put out a report that had very similar recommendations to the National Academies’ report. A very similar budget laid out for what this research should entail. And we saw it as an attempt to, along with the intelligence community and a number of different foreign policy organizations that were coming out with very similarly framed reports at the same time, push for US leadership in this field over and above other countries.

NEIL DEGRASSE TYSON: Daniele, do you have a problem with the US leading this? I know you want Italy to lead it. That’s fine.

DANIELE: I would say— yeah. I have a green card. Kind of at risk. But anyway. So— but I’ll be honest anyway, because I’ve decided to be. I just— I don't care about us leadership in this context or in any context. So in this sense, you know, I fully agree with Kevin. I do not think that this should be a US-only issue, or even a US-first issue. And part of my research, I collaborate with climate scientists and ecologists and earth system scientists from all over the world, especially Africa. I have to say, I have multiple colleagues from many African countries that are as interested as I am to understand the potential impacts of something like storage engineering, and I think that's the only way. And yes, I do acknowledge the differences in their political power. But in a way, I don't care, in the sense that that's not my part. My part is to do this from the bottom up with other scientists from all over world. Is it gonna work?

NEIL DEGRASSE TYSON: Which knows no national boundaries.

DANIELE: Yeah. And I think that's still great, right? And, so will it work? Will countries listen to us? Maybe not. But if we don't try, we'll never know. And to me, it is incredibly important to have that representation also at the level of other states, and make sure that scientists from all over the world have the information they need to inform their countries about this issue. [APPLAUSE]

NEIL DEGRASSE TYSON: You got one. You got an applause.

DANIELE: Very good. I know.

NEIL DEGRASSE TYSON: Who hasn't gotten an applause yet? We'll work— [LAUGHTER].

DANIELE: It was the green card. They’re like, “They’ll deport this guy in a month. Let's clap.” [LAUGHTER]

NEIL DEGRASSE TYSON: We're going to wrap up in a couple of minutes, and then we're going to open for Q and A from you. But I want to just bring something up which intrigued me, and I only recently learned about it just in the nick of time to be asked, on national television, this question. So let me just establish a couple of things. I don't know who of you has the expertise to bless it or not, but I'll just state it. So, ordinary pollution that many of us old timers in the room grew up with— smokestacks and this sort of thing. Yeah, there's CO2 going into the air. There's also soot that you breathe in. And I remembered— some of you might remember— you'd walk around in the morning and you’d have to brush off the ash that had landed on your shoulders from incinerators of apartment buildings that burned their garbage. Okay, that's what I remembered, growing up. So you're inhaling this. This can cause respiratory problems.

There's also sulfates coming out in this pollution. Those sulfates, over all those decades, have been persistently put into the atmosphere. Not high up. But it didn't have to be high up, because even if it fell out quickly, a fresh batch went up the next morning. And so isn't it true that those sulfates, the kind you want to put up to block sunlight, was actually blocking sunlight for most of the 20th century in a way that delayed the effects of global warming, masking what was sort of brewing underneath? So that, in fact, we were an unwitting part of a geoengineering experiment. And so now that air is cleaner, the temperature rise is accelerating. So what do we do? How— what—

DANIELE: Right.

NEIL DEGRASSE TYSON: Do you just say, “Burn baby,” you know, “Bring back the smokestacks?” What do we do?

DANIELE: So, thank you for—

NEIL DEGRASSE TYSON: And— and— how many— what’s the number— how many people die each year of respiratory illnesses, avoidable, because of the traditional pollution? How many people?

DANIELE: Millions.

NEIL DEGRASSE TYSON: Millions.

BETH: Tens of millions.

DANIELE: Tens of millions in the whole world.

NEIL DEGRASSE TYSON: In the whole world.

DANIELE: Yeah.

NEIL DEGRASSE TYSON: Okay.

DANIELE: So I really want to underscore something Dustin said in his first intervention, which is, yes. Cleaning up our air quality has immense benefits. Weaning ourselves off fossil fuels will have way more benefits just on the climate side, but most of them will be immediately felt by the people that will breathe cleaner air. And we should always be in favor of cleaner air. Defend the EPA with all you've got. [APPLAUSE] And on this, the US has an incredible success story in this. Ronald Reagan realized how important it was to have good air quality, and started cleaning up our air. And the US has been reducing the amount of pollution that they put up in terms of sulfate and soot, by a great deal. And that's great.

But on the other hand, there was a trade off. And the trade off was that we knew— and the IPCC knew already in the early 90s— that removing

NEIL DEGRASSE TYSON: IPC, International—

DANIELE: The Intergovernmental Panel for Climate Change.

NEIL DEGRASSE TYSON: Intergovernmental Panel for Climate Change.

DANIELE: They already knew in the early 90s that these removal of aerosol was going to unmask a small part of the warming produced by greenhouse gasses. And yet, in this case, the trade off was so obvious. Air quality kills so much more than climate change does, for now, that it was just— it just made sense. Even acknowledging the complexity and acknowledging the trade off and the risks, it just made sense from a fair perspective, from an air quality, from many perspectives, to remove these pollution.

NEIL DEGRASSE TYSON: I don't know if I'm alone in this, but when I hear about people's respiratory problems, I don't often hear it associated with air pollution. And so this seems to me, at least, a hidden cause of death.

DANIELE: Totally.

NEIL DEGRASSE TYSON: A hidden— I mean, the respiratory illness is not hidden. But the cause of it.

DANIELE: Yeah.

NEIL DEGRASSE TYSON: Is a hidden— and asthma, and all the rest of the breathing problems that we get.

DANIELE: And you know, another thing that doesn't set— and an unfair one at that— as in, not everybody breathe breathe the same polluted air. And it's clearly Black communities, poor communities, the communities that live closer to highways, that breathe in most of that pollution. The pollution that is brought by the oldest stuff that we move around.

NEIL DEGRASSE TYSON: Dustin, what's that called, when you—

DUSTIN: Energy injustice.

NEIL DEGRASSE TYSON: Energy injustice. Tell us what that is.

DUSTIN: Well, I think about it two different ways. One of them is what was just described, where some communities are overburdened with fossil fuel pollution or industrial pollution. But it also is—

NEIL DEGRASSE TYSON: Is it like, the lower rent section of town is near the power plant, for example?

DUSTIN: Yeah. Yeah. I used to work in the chemical industry right down in Linden, New Jersey, where all those refineries were. And there's communities that live and breathe that air every day. And that would be an example of energy injustice, All this energy production, people being exposed. The other piece to that, though, is access to energy. And that's where we have a lot of people— actually, I think more people die of indoor air pollution in developing countries than malaria every year.

NEIL DEGRASSE TYSON: Indoor air pollution.

DUSTIN: Indoor air pollution.

NEIL DEGRASSE TYSON: What is that?

DUSTIN: That's from cooking using fuels that are not modern fuels. So burning wood, burning dung, burning things like that indoors—

NEIL DEGRASSE TYSON: For cooking.

DUSTIN: For cooking purposes or heating purposes. Yeah, and that's— so energy inequity or energy injustice is both a question of access to modern energy resources. as well as overburdened communities.

NEIL DEGRASSE TYSON: All right. It sounds like— I don't know that there's any solution here other than yours. But Beth, you don't have confidence in the international community to come to agreement on anything. And I agree with you on that. But all right, Daniele has a solution. And so—

BETH: Is it a solution?

NEIL DEGRASSE TYSON: I guess not.

BETH: Is that the solution? And I respect his scientific expertise on this. I'm not sure it's a solution, though. I think it's a stop-gap measure that we're trying to apply, in what we think is our scientific wisdom, to the global— to the planet, without—

NEIL DEGRASSE TYSON: Don’t you want him to be available to you if nothing else works?

BETH: Yes, I do want him to be available to me. Hi. Yes, I'll call you later.

DANIELE: I really like you, Beth. You know that.

BETH: I do want him to be available to me in this regard. But I think we need to rethink the framework that we're deploying these technologies in. Right now, every state is looking out for its own interests, and if they see that deploying these kinds of technologies, developing them, researching them and so on—

NEIL DEGRASSE TYSON: But we say state, you mean country.

BETH: I mean country, right. If they see this as their interest, they're going to pursue it, irrespective of any treaties or anything. And I think the way out of this— you think I'm doom and gloom. Here, I'll give you a trap door here. The way out of this, I think, is going to be—

NEIL DEGRASSE TYSON: And that's a good trap door.

BETH: Yes. I think — there’s a pillow underneath. I think that the way out of this is, we have to rethink this idea of sovereignty. And I think we can do it. Even if it's selectively applied, we can think of a new security paradigm internationally that will allow us to respect the environment more.

NEIL DEGRASSE TYSON: And how does sovereignty extend above the troposphere? Is that possible?

BETH: It scientifically doesn't. No. But every country is going to think it does. They're going to make their own decisions based on their own airspace because, for some reason, they think they can control it. And you might say, “Yeah, US Army, I'd like to see to stop that heat wave.” They can't. But they're still making the decisions as though they can. So we have to tell a new story, if I can borrow Holly's parlance for a minute. We have to tell a new story about sovereignty and security. And that story is called ecological realism. That story is about how the environment, a healthy environment, sits at the basis of your security on this planet. Because you cannot be divided ecologically from any other country. You can opt out of the trade regime. You can opt out of the human rights regime or or new the nuclear weapons regime. You cannot opt out of the environment.

NEIL DEGRASSE TYSON: We all occupy the same ecosystem.

BETH: Yes.

NEIL DEGRASSE TYSON: Is that a fair way to characterize that?

BETH: Yes. That is absolutely true. Yes.

NEIL DEGRASSE TYSON: Okay. [APPLAUSE] Dustin, in a free country— which we tell ourselves we live in— we can argue forever about what should happen, because it works scientifically, because you've got a model, because— we can do that. But at the end of the day, don't we just do what's cheapest to do? And so the plan should really be economic, shouldn't it? If you want to change people's behavior in a free country, then, short of beating them on the head, convincing them that way. Just make this option cheaper than that option. Won't the whole system just flow without any concern for— or any of these issues that are being raised?

DUSTIN: I mean, not— unfortunately, I think we do tend to take the cheapest option with a lot of these solutions that we bring forth. But again, going back to a point I made earlier, I think that's because we don't value a lot of the things that we degrade already. We don't value other species on this planet that we share. [APPLAUSE] We don't value human communities. We don't value—

NEIL DEGRASSE TYSON: That was cheap applause. In this museum, we have species everywhere on display. That was a cheap applause, you got that.

DUSTIN: We don't value—

NEIL DEGRASSE TYSON: It was authentic, but it was an easy get. Right. Go.

DUSTIN: We don't value the equity dimensions we just talked about. So there's a lot of other things that are— and I'm not advocating monetizing all of those things either, because I think that that also opens up the door to— you know, the tentacles of capital and problems that happen in a capitalist economy. So, I don't think the path forward is the least-cost solution. I think that that leads to more problems. We end up— you know, I see in my own work where the cheapest solar farms are promoted as a solution, and those are often the ones that have the biggest impact on wildlife and things like that. Even a technology that we all love. So.

NEIL DEGRASSE TYSON: So you want people to not just think economically, but come to some valuation of nature that factors into their economic decision?

MALE VOICE: Right. To understand that there's other things than just monetary.

NEIL DEGRASSE TYSON: Howard, what you got?

HOWARD: So, everything we do has a carbon footprint. How we got here tonight, what we ate for dinner, all carbon footprints. The way to do it is to send price signals, and then people adjust their things. And, like, 99% of the economists say the way to do it is to price carbon. And there's a lot of proposals out there. Twenty years ago, there were actually some bills in Congress.

NEIL DEGRASSE TYSON: This would be carbon credits.

HOWARD: Well, a carbon tax, or cap and trade. But politically, we have moved away from— and in this political climate we live in today, it's really a pipe dream, thinking you're going to have a price on carbon anytime soon. So what we're left with is what the economists call “second-best solutions”. Even those are getting hard to implement. And because we're not doing the things— I mean it is— you know, it is so much cheaper to reduce our carbon emissions. My book on carbon removal coming out, the last sentence is, “The best way to remove carbon from the atmosphere is not put it into the atmosphere in the first place.” And we are having a hard time doing that.

The Rio convention was 33, years ago, 1992, where we said we're going to lower our emissions. We have more emissions today than we had then. So, you know, that's why people are looking at things like geoengineering. I look at it like a Hail Mary pass in football, where you really don't want to get to the point where you're forced to do a Hail Mary pass, because they don't always work. In fact, they usually don't work. Yet that's the road we're going down to. That's the reality of the situation. And I wish I had an easy answer, but I don't.

NEIL DEGRASSE TYSON: Holly, we're told that we need to reduce our carbon footprint, so that you feel good when you do that, if you have the resources to accomplish that. But if we all reduced our carbon footprint, is that enough? Aren't there whole industries out there that have a way bigger carbon footprint than any one of us?

HOLLY: Yes. And I do think starting with industrial emissions makes sense, in a way. But actually, the thing about the carbon footprint is there's that personal connection. And believe it or not, people in the US are interested in doing their part. They want to do something. They talk endlessly about recycling. They also feel like that was kind of a scam, and they feel disappointed because they were actually bought in and they thought it— they want somebody to tell them, like, “Here's the steps that you can take.”

NEIL DEGRASSE TYSON: You're referring to the fact that in the 1970s we were all convinced that we were the bad ones by littering, when we were being sold products that had a lot of stuff to discard once we consumed the product. And so— but we thought it was our fault?

HOLLY: Well, I was thinking more about like, the ‘90s, when recycling was the thing you could do. And, you know, people related to it on a personal level. They had specific behaviors that they were willing to engage in. And so I think that personal dimension is important. But I also think that, yeah, there's big structural changes with how things are produced that are also important. And people get that.

NEIL DEGRASSE TYSON: And does that cross international boundaries? We're pretty wealthy here. Even the poor of us are wealthy relative to other countries. So what a luxury it is to say, “I will, you know, eat these foods that cost more than these other foods because it has a smaller carbon footprint.” If I'm starving, I'm not making that decision.

HOLLY: Well, I don't want to start talking about international trade. That's a mess. But yeah, there may be things we could do in that realm too.

NEIL DEGRASSE TYSON: Maybe things we can do in that realm.

HOLLY: I don't— I just don't want to talk about tariffs, border adjustments or any of that tonight.

NEIL DEGRASSE TYSON: Okay. All right. So, let's land this plane. So what I want to get from each one of you is your most hopeful vision. And I'll skip Beth, because I don't know that she has a hopeful vision here. [LAUGHTER] Kevin, professionally, you've been quite grumpy. You've been very polite tonight. But professionally, your published works are quite grumpy.

KEVIN: True.

NEIL DEGRASSE TYSON: So give me something to look forward to.

KEVIN: I'm told there might be wine after this event. [LAUGHTER]

NEIL DEGRASSE TYSON: Okay! Oh, sorry, Kevin, go on. That was not your answer? Okay, no.

KEVIN: And I really don’t know if I want to answer that question. I want to just— before we leave the room, I would be remiss to not— because of the last two comments— the one reason we're talking about solar geoengineering is because it's so cheap, right? It is a— in my opinion, a potential Get Out of Jail Free card for all of the very difficult things that we have to do that will actually make the world a better place. And it might not be just a stop gap measure, because it is so cheap. It might have to continue for centuries, right? And it would potentially get— the more stuff we have to put in the stratosphere, the worse the side effects get. So I think before—

NEIL DEGRASSE TYSON: So it’s not a solution, it’s a band-aid.

KEVIN: If that, yeah. So I think we need to— if we're at a point where we do need an extreme Hail Mary intervention like solar geoengineering, my preference would be to think more extreme about extreme interventions into the economic system that is driving this. [APPLAUSE]

NEIL DEGRASSE TYSON: Okay, it's like the time we've heard the term Hail Mary. For those who are not football fans, the very last play of the game, if the team that has the ball is either tied or behind and they just have to score a touchdown, and then they'll win the game. So they start the play. The time runs to zero, so they have to make this play. And they're not going to trust running with the ball, because you could get tackled. So the quarterback takes the ball and throws it high into the air so it just lands in the end zone. And everybody's huddled around trying to catch the ball as it arrives. And you're hoping one of your players catches the ball. And if he does, it is a successful Hail Mary pass. Otherwise, I don't know that we have a word for it, but it’s— you're putting it all on that last throw. Just in case people needed to be updated on football reference. Holly, give me something to look forward to.

HOLLY: So, I've been around the country for the past two years talking to people, including a lot of Trump voters. And people— obviously, they're really fed up with the status quo. They're fed up with big corporations taking advantage of them and their communities. And I think that there's actually a huge opportunity here that some political parties have failed to take advantage of that could shift things in the right direction, if we found leadership that could talk to lots of different audiences. I actually feel, despite this being like maybe the darkest moment, there's a lot of potential for political change in this country that can move things on energy. [APPLAUSE]

NEIL DEGRASSE TYSON: Beth, that's how to be hopeful.

BETH: Okay.

NEIL DEGRASSE TYSON: Okay, can you take a cue from that? What do you have for me?

BETH: Yes, I can. I do think that if enough countries get together to form some kind of anticipatory governance structure, we can maybe get some of the big powers to sign on to it. I think if we govern—

NEIL DEGRASSE TYSON: Wasn’t that the UN? Isn’t that what the League of Nations, the UN— What are you talking about?

BETH: Well, the UN would be the basis for it, right? But if we govern geoengineering like arms control, then we might be able to get enough states to sign on to say, “Okay. We think that if— as long as everybody else agrees, we'll agree too.” And we might make some progress that way.

NEIL DEGRASSE TYSON: Okay, so it's a geopolitical solution to moving forward.

BETH: Yes, it is. But I don't know if it’s the solution we all need. It’s solution we can have in the moment.

NEIL DEGRASSE TYSON: Gotcha. All right. [APPLAUSE] Dustin. Give me your best solution going forward.

DUSTIN: Well, I'll bring you an example from California, where I spent most of my life. First half my life here in New Jersey, and lived the second half here in California.

NEIL DEGRASSE TYSON: And you came to this museum as a kid.

DUSTIN: And I came to this museum as a kid in the school bus. I recognize all the halls. Came to the planetarium when it first opened.

NEIL DEGRASSE TYSON: Now, you saw Laser Floyd. Be honest.

DUSTIN: Oh, I saw Laser Floyd at the old planetarium. But we've had, you know, several months-worth of the year where we're running on 100% renewable energy. We have batteries now powering— carrying almost 30, 40% of the load in the evening when the sun goes down. And those are filled with the sun during the daytime. And we're still 20 years away from what our 100% goal is, in the state. So we're rapidly evolving a renewable energy system that's displacing carbon emissions. And that's really the name of the game. To stop—

NEIL DEGRASSE TYSON: And that's happening steady. Slow and steady, so that you're not noticing a difference one day to the next. But maybe we'll wake up one day and the carbon footprint has been shrunk?

DUSTIN: At least on the electricity side.

NEIL DEGRASSE TYSON: Yeah. To insignificance.

DUSTIN: The points of the fertilizers and the points about the animal agriculture are still out there, need to be addressed. But rice production in California, we've done substantial reductions in methane emissions from rice production, which is another source from agriculture.

NEIL DEGRASSE TYSON: Because rice germinates anaerobically, and so oxygen is not part of it. So one of the by- products is methane. So, CH4, without oxygen.

DUSTIN: This is the best host you got here. This is great.

NEIL DEGRASSE TYSON: [LAUGHTER] So, Howard, help us out here? What's your vision of the future?

HOWARD: So there's a lot of technology out there that can really help us reduce our carbon emissions. And there's actually more tech— you know, there's more technology out there that we can get implemented, whether it's renewables, whether it's nuclear, whether it's electric vehicles. The problem is the incumbents, fossil fuels, are so cheap. So these technologies—

NEIL DEGRASSE TYSON: Cheap and portable. Cheap and portable.

HOWARD: What?

NEIL DEGRASSE TYSON: You know, you dig it out of the ground and move it to another place.

HOWARD: Yes. Plus, technology has also improved the production and use of fossil. So in order to get these new technologies to really get deployed and do it, you need policy. And you know, the example of California, that didn't happen organically. California put in a lot of policies to do that. That's what we need for the rest of the country. That's what we need for the rest of the world. But so technology did not do it.

NEIL DEGRASSE TYSON: Enlightened, management of utilities, in this way.

HOWARD: Say it again?

NEIL DEGRASSE TYSON: Enlightened management of utilities.

HOWARD: Yeah. It’s— well, you know, it's not just utilities. It's— because a lot—utilities are about 30% of the energy we use. So it's everything in the economy. But there's technologies for everything in the economy if we put the policies in place that move us towards that. Now, if we did this 20 years ago, you know, you can slowly put it in. The more we wait, the harder it is, because we need to do it faster.

NEIL DEGRASSE TYSON: Daniele. Visioni. Take us out.

DANIELE: Well, I want to say that sometimes even if you have no hope at all, you still got to do what you think it's right. And this could be really one of the cases. I don't think we should think about this in terms of hope, but as much in terms of, this is our responsibility. This planet is our responsibility. Have we messed up? Yes. But we've messed up in the past, and this shouldn't let us stop from thinking about, what can we do next? And in a way, yes, something like solar geoengineering is scary. And of course it is. And it should be. I hope it stays scary. But on the other hand, it could be part of what gets us out of all of these, especially if we acknowledge that that's not the only thing. Especially if we acknowledge the larger problem, especially if we acknowledge our responsibility for this planet. That's the part in which solar engineering could play a part, and allow us to move past, and actually become the real steward of this planet.

NEIL DEGRASSE TYSON: Thank you, panel. [APPLAUSE] Normally, this is the moment where I offer my personal reflections. But that would be gilding the lily that you've witnessed here, with six articulate scientists bringing us to their frontier on this topic. Let's thank them again. [APPLAUSE]

So we're setting up microphones in each aisle, and— I think it’s in each aisle. Yes, there is. So let's go right here. Let's start out. Sure, hello, hi.

MALE-PRESENTING QUESTION: Hi. So for years and years and decades, we've had warnings and red lines and tipping points. And when they cross and the world doesn't literally end, skeptics are emboldened to dismiss the whole concept. So how important is communication, and are we doing it wrong? Is there a better way to be real, but get across how important it is?

NEIL DEGRASSE TYSON: Yeah. Who can address that here? So you have models, and you make a prediction, and it makes the news because you're making a dire prediction. And then the dire prediction doesn't come true, and then people might lose some confidence in your next prediction. So, you have— sure.

HOLLY: I'll say one thing, I don't think we should talk about climate emergency very much, because that invites conditions that we might not want. New moves we might not want politically. I think, also, talking about these deadlines has been an issue. I think we should focus on what the benefits of decarbonization are for people.

NEIL DEGRASSE TYSON: Okay. So if someone has a dire prediction, should they not bring it to the press? Should the press be left out of the room? Howard. If you have a dire prediction, should you withhold that from the public, because you might be wrong, and then they don't believe your next prediction?

HOWARD: Well, I think the climate community, the modelers— you know, they don't give out dire predictions. There's a lot of uncertainty, and they talk in uncertainty. And I think the problem is— and these models are very good, and they're getting better, but they're not perfect. The problem is, you know, there's a whole industry out there of denial. And they just nitpick, and you get this other information out, and—

NEIL DEGRASSE TYSON: Cherry pick. They cherry pick.

HOWARD: They cherry pick, and the like. So, you know, I work with a lot of the climate scientists, and they're very conservative when they make the public things. You know, there's things they worry about. But I haven't seen anybody make, you know, end of the world predictions. At least not what I would call reputable scientists.

MALE PANELIST: There's a recent paper from a Rutgers University Professor named Bob Copp that that addresses this question specifically about tipping points, and moving away from that particular framing. So.

NEIL DEGRASSE TYSON: Okay. So that's an evolution in scientists communicating with the public.

MALE PANELIST: Exactly.

NEIL DEGRASSE TYSON: So that the understanding is more accurate than the intent.

MALE PANELIST: Yeah. It's a reflection, I think, of what what the commenter said.

NEIL DEGRASSE TYSON: Excellent. Good to know that. Right here, yes, next. Yes, next.

MALE-PRESENTING QUESTION: You were talking about the need to continue fossil fuels to handle the electrical base load. But as one of the people said, with energy storage, pump storage, batteries, wind and solar can, over the next few years, totally replace fossil fuels. But we've got a political climate that's going to prevent that. How do you get around that problem when the technology has been solved?

HOWARD: So, so energy storage is getting cheaper, and it's actually being used. The utilities are using it. So let's look at these batteries. If we have a battery and we charge it and discharge it every day, the batteries are expensive. We charge and discharge it every day. We have a lot of days to do it. But there's also times, what we call more long-term storage, seasonal storage, and the like. And batteries aren't up to that, to do it. So basically, what we're doing now in the country is we use gas turbines to balance the load. Now, we'll get more and more with storage, but— you know right now, it's always an economical decision, And as they say, the incumbent is gas turbines. Now, if you say, “Okay, we can't use the gas turbines to do that.” Or—and maybe we, instead of running the gas turbines on, say, methane, we may run them on hydrogen, which doesn't emit fuels.

But you know, there's always going to be— it's very— I mean, the electric industry, you know— some people say we have a third world grid. But it's an amazing thing that— demand and supply have to balance every second of every day, 24/7. And so it's a complicated thing. And as I say, we're moving more to using batteries and storage in there, but there's a lot of applications that that just can't fit yet. As I say, the longer term storage. You know, if we have a week or two with no wind or solar, that's a real issue. And you're not going to solve that with batteries.

NEIL DEGRASSE TYSON: Dustin, make it quick.

DUSTIN: Just to say that batteries are much— they can discharge much more quickly, and they're going to turn out to be much more reliable. You could build solar and batteries much, much more quicker than you can build a turbine. And we have a supply chain crisis with turbines.

NEIL DEGRASSE TYSON: And just to remind people, at night where there is no sun, you can't use solar power unless you had extra solar power during the day that got stored by some means.

DUSTIN: Or you put them up in space. Isaac Asimov suggested.

NEIL DEGRASSE TYSON: Oh, yeah?

DUSTIN: Yeah.

NEIL DEGRASSE TYSON: What did he say?

DUSTIN: He said that we should put big solar panels out in space and beam back radio waves.

NEIL DEGRASSE TYSON: Okay. Because you can get far enough from Earth so there's no day or night cycle, and there's no clouds or rain. Okay. I think the Chinese are thinking about something.

DUSTIN: Yeah. No, there’s a company that got a power purchase agreement from about 10 years ago. They never succeeded. But, beam it down to Fresno, California.

NEIL DEGRASSE TYSON: Beam it to Fresno. So this is a beam of energy from space.

DUSTIN: I write about it.

NEIL DEGRASSE TYSON: What could go wrong with that as you pass through it? Next question here, yes. And by the way, how old are you?

12-YEAR-OLD QUESTION: I'm 12.

NEIL DEGRASSE TYSON: Twelve. Cool. [APPLAUSE] When I was 12, I came to almost every event here at the museum. So great to see that tradition continued. Yes. What you got?

12-YEAR-OLD QUESTION: If we were to trap carbon dioxide and make it into a battery, to like—say we have solar panels. We can have another way, another form of energy to power other things. So if we trap carbon and make it into a battery, is that another way of— I'm not sure how to explain it, but is that another way of—

NEIL DEGRASSE TYSON: So you're thinking, could there be some loop that we'd create where you have solar energy, making a battery out of the carbon that we're trying to remove, and then it's sort of a self-feeding system?

12-YEAR-OLD QUESTION: Yes.

NEIL DEGRASSE TYSON: Started with sunlight. But is there such a thing as a carbon battery?

DUSTIN: You can compress air. So maybe some of these filter systems.

DANIELE: That's what fossil fuels are.

NEIL DEGRASSE TYSON: Oh, wow. That’s deep.

DANIELE: Right. I mean, I think— I think it's a great idea. But that’s what the planet does.

NEIL DEGRASSE TYSON: Wait, I got this. I got this. You ready? Okay, fossil fuels are carbon stored energy. That's a brilliant analogy for my podcast, StarTalk. One of our episodes, we went to England to shoot a Formula One race, okay? And we interviewed the engineer—a Ferrari engineer, actually. Italian, are they not? Yes. Okay. [LAUGHTER]

DANIELE: Used to be.

NEIL DEGRASSE TYSON: And what I learned, what I learned is Ferrari is going to go net zero by 2030. And there’s an energy company— Aramco, I think it is— that pledges to artificially make gasoline. Artificially. So you're going to take the chemistry that would— so, why does gas have power? Because the molecules have stored energy. And you break apart the molecule by burning it, and the energy comes out. But you could make that molecule if you started with energy to recreate it. And so they're using solar power to create gasoline, so that the ordinary gasoline that's used in the cars, was made by the sun and not drawn from the earth after millions of years of fossil activity. And they're going to take the carbon dioxide out of the tailpipe and sequester that in some way. But they're going to have a net zero footprint. And so they're using the sun to make gasoline. Why not? Why not? Let's go up top. Oh my gosh. We’ve got a question up top.

FEMALE-PRESENTING QUESTION: So in addition to geoengineering, and in addition to the move to renewables, the lifestyle in the West is obviously unsustainable in current technology. Would the technological transition be enough, or will there need to be changes in individual consumption? And what would that look like?

NEIL DEGRASSE TYSON: Sounds like nukes, to me. Not spoken often enough on this panel. She's saying our future needs don't even look like they're going to be accommodated by anything that's en route right now, unless there's some sea change in what is going on. Yes, Holly.

HOLLY: Yeah. I think it's a mistake to think about social change and technological change as a binary or even separate, because adopting these new technologies, like a heat pump in your house, you have to change your behavior. So do the installers. And also some of the social changes have technological enablers. So thinking about moving to a plant-based diet. There's different technologies that enable new plant-based foods that make it more appealing for people. So they can work together. But yeah, I do think changes to almost every aspect of our life will be involved.

NEIL DEGRASSE TYSON: I'm reducing my meat consumption, not for any health reason, but just to try to contribute my little bit to the reduced carbon footprint. I mentioned this to Peter Singer, who, by many people's measure, launched the modern vegan movement in the West. And he said, “Oh, so you're reducitarian.” So I thought, “Okay, I guess that's what I am. I'll take that. A reducitarian.” Kevin, yeah.

KEVIN: Yeah. I wanted to add to that as well. One trouble— one thing I find troubling in these conversations is that we're talking about replacing fossil fuels with new forms of energy, or needing to integrate new technologies to meet continual economic growth, right? So, what are we growing? And who's making decisions about what aspects of the economy need to grow? I was talking earlier about, you know, what are the kind of irrational things that comes out of these conversations? Someone like Sam Altman, the billionaire founder of OpenAI, has said, “We're going to need solar geoengineering because we're going to need tons more data centers that are really energy hungry, to power AI.” Right? And why are we driving forward with AI when we have so many other more pressing social problems?

NEIL DEGRASSE TYSON: Unless we can do it all. Unless we can do it all, and stick a nuclear power plant outside his AI data center.

KEVIN: That's the next Asimov panel.

NEIL DEGRASSE TYSON: Okay. [LAUGHTER] Thank you, up top. Yes, right here.

MALE-PRESENTING QUESTION: So I want to preface this question by saying that I'm atheist, anarchist by conviction, social democrat by pragmatism. But I feel that we're—

NEIL DEGRASSE TYSON: Friend of Trump. Yeah, okay.

MALE-PRESENTING QUESTION: I feel that we're living a huge intersectionality with the serious Christian people in this country, when we talk about climate crisis. One of the most powerful conversations I've seen was the conversation that led Pope Francis to care about climate crisis, which was the social aspect. That the people that benefited the most from climate change are not the people that are being hurt the most. And are we leaving— by taking a skeptic [?] perspective on this discussion, leaving intersectionality with serious religious people in America?

NEIL DEGRASSE TYSON: So first of all, I think it was the Pope's Encyclical. Did I say that?

MALE-PRESENTING QUESTION: Yes.

NEIL DEGRASSE TYSON: Encyclical, where he had a section— I'd never seen a Pope before talk about climate change. So that was quite significant, because that his doctrines matter to nearly 2 billion people in the world. So religion has power over people, as you clearly know from your question. But Holly, where does religion fit in this? You have access to people who are deeply religious, and therefore have a different view of all of this.

HOLLY: Yeah, I think it's really central for a lot of people. I've heard people who have concerns about hubris and playing God, and what these ideas mean about our place in the universe. I've also had conversations about care and stewardship. And so I think it's complex, but it's definitely a central part.

NEIL DEGRASSE TYSON: But is there hope there? I guess not. Okay. Daniele. Yes.

DANIELE: Super brief. But yes, this is an important conversation to have. And for instance, I think it's in— she's in your same institution. Kate Hayhoe. She's one of one of the more prominent climate scientists in the US, and she's an Evangelical. And she acknowledges very often this intersection. They also had an ad during the during a football match. Whatever it is, the Super Bowl thingy.

NEIL DEGRASSE TYSON: This is America, jack. You better know what to call that.

DANIELE: So yes, it is an important conversation. But really, not one we're ignoring. But an important one for sure.

NEIL DEGRASSE TYSON: Yeah. And they definitely— if they don't have a seat at the table, they will make sure they do. Right? Time for just a few more questions. Yes. And how old are you?

10-YEAR-OLD QUESTION: Ten.

NEIL DEGRASSE TYSON: Ten. All right. [APPLAUSE] Wait a minute. You’re not ten and a half?

10-YEAR-OLD QUESTION: No.

NEIL DEGRASSE TYSON: Okay. [LAUGHTER] Okay, what you got?

10-YEAR-OLD QUESTION: In this conversation, you're talking a lot about nuclear energy. And I'm not worried about, like, nuclear warfare, but, like, more about, like, the power plants exploding.

NEIL DEGRASSE TYSON: You’re worried about safety.

10-YEAR-OLD QUESTION: Yes.

NEIL DEGRASSE TYSON: Yeah. So is a lot of other people.

10-YEAR-OLD QUESTION: It happened in the past. And how do we know that won't happen again, in these solutions of nuclear power plants?

NEIL DEGRASSE TYSON: Excellent question. Dustin. We had Three Mile Island.

DUSTIN: Yeah.

NEIL DEGRASSE TYSON: We have Fukushima. We have Chernobyl. And what’s the one with the movie? Was that real, or is that just a movie? With Jane Fonda? China Syndrome. Oh, that’s just a movie. Okay. So.

DUSTIN: The key—

NEIL DEGRASSE TYSON: So it happened.

DUSTIN: It happens.

NEIL DEGRASSE TYSON: It happens.

DUSTIN: You know, the nuclear industry, I think, has built a lot of redundancy into their systems to try to avoid that. But, you know, you never know what else could go wrong.

NEIL DEGRASSE TYSON: So, redundancy is, if something goes wrong, there's a backup to that, and then a backup to that.

DUSTIN: Right.

NEIL DEGRASSE TYSON: Just to make sure that you’re protected.

DUSTIN: So if you can't keep the power plant cool, there's a backup system to keep it cool. But then you sometimes learn you need another backup system if the first two fail. And you know, that's just the nature of these big industrial facilities. So you know, I think it's right to reflect on past accidents and be concerned, but I think also they have made these things more safe. When I think about injustice and impacts from the nuclear industry, my main concern is around mining and mining for uranium in the Western United States, which still continues to encroach on Native American lands and impact their water and things like that.

NEIL DEGRASSE TYSON: That's because modern— still, today, nuclear power is nuclear fission, which requires the uranium.

DUSTIN: That's right.

NEIL DEGRASSE TYSON: Maybe in the future, we'll have nuclear fusion, like they had in Back to the Future, where he's powering his engine.

DUSTIN: Yep. There you go. Or we can harvest helium 3 from the moon. Isn't that—

NEIL DEGRASSE TYSON: Yeah, that would help. Let's go to the moon and find out. Thank you for that question. [APPLAUSE] Yeah. Back up top.

MALE-PRESENTING QUESTION: All right. So I think it's been alluded to.

NEIL DEGRASSE TYSON: And how old are you? [LAUGHTER]

MALE-PRESENTING QUESTION: Twenty-six.

NEIL DEGRASSE TYSON: Twenty-six, all right.

MALE-PRESENTING QUESTION: I think it's been alluded to before, when we were talking about the price of renewable energy compared to fossil fuels, and how it's now cheaper to produce renewable energy in a lot of cases. So I'm thinking about, is it not just the vested corporate interests that exist already now, that are preventing the transition to renewables? Or are there other things going on? And what can we do to address that?

NEIL DEGRASSE TYSON: Beth. Can you take that, do you think? Like, what forces— are we being sold a bill of goods that's not what we really want, but we're told it's what is all that's available because of either corporate or political forces?

BETH: There's a lot of corporate and— as you say, corporate and political inertia— behind the fossil fuel system. They get, you know, billions of dollars in subsidies every year. At least in this country, they do. And there's very little political incentive to move our energy system away from carbon-based energy, to others. If I'm an energy company, though, this is the part where I think, “Okay, it doesn't even have to be that disruptive,” this decarbonization switch, for an energy company. Because they're fossil fuel companies now, but they could be energy companies in the future. If I'm— BP, or whatever.

NEIL DEGRASSE TYSON: If they change their names to reflect that.

BETH: You don't even have to change your name, right? You could just say, “Yeah, we're Exxon. We're into solar now.” And they might be able to replace those profits. But why would they do that, when the political structure they have worked so hard to set up rewards them so handsomely for fossil fuels? So ladies and gentlemen, we need to get— you guys need to—

NEIL DEGRASSE TYSON: Did the phrase, “We’re Exxon, we’re into solar now” —

BETH: Yeah.

NEIL DEGRASSE TYSON: Did that come out of your mouth? Just— that’s really cool.

BETH: I said possibly. But BP tried it, and then they backed off of it. They wanted to call themselves Beyond Petroleum. And they they backed off of it because the they were making too much profit with fossil fuels. So ladies and gentlemen, this is where you need to vote and get your representatives— like, once they're elected, don't leave them unsupervised. You’ve got to tell them what to do.

NEIL DEGRASSE TYSON: [LAUGHTER] No unsupervised representatives. That's the lesson of the night. Let's keep going. Yes.

15-YEAR-OLD QUESTION: So, bypassing treaties, if you could just snap your finger and make every country in the world agree to do one thing to address climate change, what would that one thing be?

NEIL DEGRASSE TYSON: Ooh. Beth. That’s right in your face, right there.

BETH: Yeah, I know. Wow.

NEIL DEGRASSE TYSON: And how old are you?

15-YEAR-OLD QUESTION: Fifteen.

NEIL DEGRASSE TYSON: You’re 15? Cool. Thanks.

BETH: If I could snap my fingers and make one thing happen, I probably— I liked what Holly said about realizing how interconnected all countries are ecologically. And, you know, the atmosphere, the biosphere and so on. If there was some way to snap my fingers and have countries realize that, I think we would see a lot more cooperation on environmental matters. And I think that would go a huge way towards not only helping to defuse the climate crisis, but to help us govern the future better.

NEIL DEGRASSE TYSON: So it's environment first.

BETH: Yeah. Yes.

NEIL DEGRASSE TYSON: And then we grow our sovereignty from that.

BETH: That's exactly what it is.

NEIL DEGRASSE TYSON: Nice. Okay.

BETH: Thank you for that question. That was a great question.

NEIL DEGRASSE TYSON: Yes. And sir, how old are you?

MALE-PRESENTING QUESTION: Actually, I'm here tonight with my beautiful family. This is my birthday present, and I'm celebrating my—

NEIL DEGRASSE TYSON: Happy birthday. You’re celebrating your—

MALE-PRESENTING QUESTION: Eightieth birthday.

NEIL DEGRASSE TYSON: Eightieth birthday. All right. [APPLAUSE]

MALE-PRESENTING VOICE: And I started walking the halls here over 75 years ago. I haven't stopped.

NEIL DEGRASSE TYSON: Excellent.

MALE-PRESENTING VOICE: And 50 of those—

NEIL DEGRASSE TYSON: It’s keeping you in good shape, too. Yeah.

MALE-PRESENTING VOICE: Fifty— thank you. Fifty of those 80 years were served in the New York City school system, in the Bronx that you know very well.

NEIL DEGRASSE TYSON: Teacher in the house, give it up, right? Okay.

MALE-PRESENTING VOICE: So you have discussed the problem, and in football analogies, we have, as our generation, kicked the football around. However, the people who will be suffering the problem were the 10-year-old, the 12-year-old, and the 15-year-old.

NEIL DEGRASSE TYSON: The next generation. Yes.

MALE-PRESENTING VOICE: And— however, they will be bearing the problem. But in those classrooms, including those kids and their colleagues in those classrooms, are the scientists who will follow you and will have the solutions. And so what I'd like to do is offer to the panel, ask them, What can we do to educate and mobilize the 10, the 12 and the 15-year-olds now? What could you do? What could we do, to get them to provide the solution to the problem that you've identified?

NEIL DEGRASSE TYSON: Let's ask our sociologist. What do we have to do in the school system to make sure that there's a next generation that is not only interested but able and equipped to encounter these problems that we will be leaving them?

HOLLY: Get phones out of the classrooms.

NEIL DEGRASSE TYSON: Ooh!

HOLLY: Step one. I know it seems simple and maybe not thoughtful, but I really think this is a big challenge.

NEIL DEGRASSE TYSON: Phones out of the classroom. Wow.

HOLLY: Then step two is use more time for creativity.

NEIL DEGRASSE TYSON: Cool. All right. That's a good solution, right there. Thank you, and happy birthday to you. Yes. Okay, time for how many? Yeah, let's do three more. Is there any up top still or—okay, let's do one more up top. Is it ready? Oh, there you go. Yeah.

MALE-PRESENTING QUESTION: Thank you for the wonderful discussion. You talked a little bit about energy injustice. And all of us, we happen to sit here in a country that was very early on in the energy revolution. So right now we are at the top, right? And then we kind of judge, almost easily, all the other people now that they try to climb the ladder as quickly and easily as we did. How energy injustice is there, as we saw also recently with Guyana oil findings and all that? Thank you.

NEIL DEGRASSE TYSON: All right. Love that question. Dustin, you hear what he's saying. He's saying, we already burned all our oil and our coal, and we built this most powerful nation in the world. Now we're telling other countries that have access to that inexpensive source of energy to not do that.

DUSTIN: Right.

NEIL DEGRASSE TYSON: And, where is the fairness there? Did I capture your question accurately? Thank you. Yeah.

DUSTIN: Yeah. I mean, built into the— and maybe you could speak to the international treaties. There is principles that the countries that have polluted the carbon dioxide into the atmosphere bear the most responsibility in making sure that they clean it up. Or they help mitigate, or help other countries technologically leapfrog, if they can, some of those fossil fuel resources.

NEIL DEGRASSE TYSON: Well, they'd have to care, first.

DUSTIN: And you have to be part of international agreements.

NEIL DEGRASSE TYSON: Which apparently are not possible.

BETH: Well, it's possible. It's difficult. But it could be done. I don't want to end on a gloomy note here. We can do this. We just have to do it. We have to make sure that our governments understand the stakes here. Because they're insulated from the effects. Most of us are insulated to some degree. But these people around the world, who we're now telling, “You can't develop using fossil fuels, find some other method or stay poor,” they will not be insulated from these effects. There's a double exposure there for them.

NEIL DEGRASSE TYSON: Yeah. I think time for only two more questions, one on each aisle here. Sorry for people that were back. Yeah, what do you have?

COLIN: Hi, I'm Colin. Please forgive any stuttering. This is the most starstruck I've been since I was asked to spot Hugh Jackman at the gym. So. [LAUGHTER]

NEIL DEGRASSE TYSON: Oh, wow. Okay.

COLIN: Mr. Visioni, I actually have a question for you about your research. I do think it's really cool, the concept of manipulating refraction index in the upper atmosphere with aerosols. But my my research background is in extrasolar atmospheres. And in early stages of extrasolar planets, with a pressure gradient at a higher density in an upper atmosphere with respect to distance from the surface, the surface of early stage planets experience a much higher impact rate of high frequency waves, gamma radiation. How would you address that in applying aerosols to Earth's atmosphere at the same respect?

NEIL DEGRASSE TYSON: So is what he's saying true? First, that if you do this to the upper atmosphere, it might transmit energy of unwanted wavelengths down to the ground? Is that pretty much what you're saying?

COLIN: Yes.

DANIELE: It is true, if you think about sort of incredibly long geological scales and completely different states of the earth. But in this case, again, I would just tell you— first of all, already 30% of solar radiation is reflected by the planet. And a lot of these reflections happen—

NEIL DEGRASSE TYSON: That’s from our ice and our clouds.

DANIELE: Ice, clouds, and aerosols at the surface. So really, changing that by 1% would not affect the atmospheric composition in terms of much—

NEIL DEGRASSE TYSON: How transmissible it would be.

DANIELE: How transmissible it would be, especially at those wavelengths. And again, why do we know that? Because there have been multiple volcanic eruptions, and those are much larger than anything humans would ever do. And we've seen what happened after that. We have that upper bound to allow us to understand what are sort of the upper bound of risks connected to that. But—

NEIL DEGRASSE TYSON: That’s your safety net, in your predictions.

DANIELE: Yes, it is. And in the observations as well, not just in predictions. Yes.

NEIL DEGRASSE TYSON: Okay. We have an eager person whose arms are ready to fall off, so why don't you go next here. Go ahead. And how old are you?

15-YEAR-OLD QUESTION: I’m 15. So in addition to asking this question to the panel members, I'm a sophomore at Stuyvesant High School. I know that— I believe your son was there. I was wondering if you could, like, offer a quote that I could, like, put for my yearbook when I graduate.

NEIL DEGRASSE TYSON: A quote?

15-YEAR-OLD QUESTION: Yeah, something inspirational.

NEIL DEGRASSE TYSON: Yeah. I'll offer you a quote right now.

15-YEAR-OLD QUESTION: Okay.

NEIL DEGRASSE TYSON: Are you ready?

15-YEAR-OLD QUESTION: Yeah.

NEIL DEGRASSE TYSON: Because when you're a senior, you'll be applying to colleges.

15-YEAR-OLD QUESTION: Of course.

NEIL DEGRASSE TYSON: Right? And people will be climbing over each other to get into elite schools, because you’re coming from an elite high school. And I can tell you— and no one else is going to tell you this. Whatever you do not achieve in life will not be because of what college you did not attend.

15-YEAR-OLD QUESTION: Okay. Thank you so much. And then— sorry, I still have one question.

NEIL DEGRASSE TYSON: What you got here?

FEMALE-PRESENTING QUESTION: Hi. Thank you all so much for this fascinating discussion, by the way. I'll try to be brief. I think that the question—

NEIL DEGRASSE TYSON: No, don’t try to be brief. Be brief. There is no try. Do or do not. Okay, go.

FEMALE-PRESENTING QUESTION: Okay, Master Yoda. I think the answer might be very similar to the one that you gave two questions ago. But I want to raise a potentially naive concern about solar geoengineering, which is that if you increase the albedo of the earth enough, you would potentially result in, for example, disruptions to plant photosynthesis, and possibly an increased possibility of acid rain. Just because, based on basic stoichiometry, if you put in enough SO2 into the atmosphere, there's hydrogen mixing up in there, you'll end up with sulfuric acid. We know from Venus, and we know from what happened in the KP extinction event, that acid rain does happen in those moments.

NEIL DEGRASSE TYSON: Formerly known as KT extinction. Yes.

FEMALE-PRESENTING QUESTION: Yes, formerly known as that. You are correct.

NEIL DEGRASSE TYSON: Yes.

FEMALE-PRESENTING QUESTION: But my question is, even though we're controlling the amounts of SO2 we'd be pumping into the atmosphere, even though hopefully we wouldn't face these issues, how do we deal with the increase in probability that these things will happen? There are three potential answers I can—

NEIL DEGRASSE TYSON: I got you. No, I got you. We got the question.

FEMALE-PRESENTING QUESTION: You got it. OK. And maybe it's just a naive question, but.

NEIL DEGRASSE TYSON: OK. So, I’m going to consolidate what she just asked. If we're going to change the reflectivity of Earth, there's less sunlight hitting plants. Then what effect does that have on crops or crop yields? If you're taking 1% of sunlight away, is that taking 1% of my crop yield away? And that's in the margins of my profits?

DANIELE: Okay. So.

NEIL DEGRASSE TYSON: And I'm blaming you.

DANIELE: Right.

NEIL DEGRASSE TYSON: Yes.

DANIELE: Two answers. One on point, one broader. You'll have to allow me these. The first one is, yes. By increasing scattering, you reduce direct incoming radiation. You also increase diffused radiation. And we know diffuse radiation increases crop yields and increases net primary productivity. And, you know one could be— yeah.

NEIL DEGRASSE TYSON: So the light comes in, some of it gets reflected, but most of it gets diffused into the atmosphere so that the sky brightness goes up.

DANIELE: Yes.

NEIL DEGRASSE TYSON: Giving light from directions that the sun might not have otherwise reached.

DANIELE: Yes.

NEIL DEGRASSE TYSON: OK. This is an interesting fact here.

DANIELE: But let me give you a broader answer, too. That’s not a naive question. That's a great question, and that's exactly the kind of questions we're trying to ask, and we should be asking way more. The point of talking about this topic, and the point of doing research in this topic, is not providing to you the definitive answer today, but making sure that we expand the amount of people that are asking this question, try to figure it out altogether, and then eventually build together towards an answer that also highlights the trade off. This is not a naive question. Thank you for asking that.

NEIL DEGRASSE TYSON: Well, there’s a second half, which was, the aerosols that are sulfates, when that comes out of the atmosphere, creates acid rain. So aren't you creating an acid rain nightmare in the future, if you get your way?

DANIELE: Two numbers. So, this is another fair concern. Currently—

NEIL DEGRASSE TYSON: That was a yes/so question, I thought.

DANIELE: Right.

NEIL DEGRASSE TYSON: Okay.

DANIELE: The answer is, currently, we're putting up 100 billion tons of sulfate every year just out of pollution. That number is going down, unmasking the problem, and so on. With 1% of that, you would achieve the same cooling if you did that in the stratosphere. Does it mean that it would not be an issue? No, but it would mean that it's an issue that, in a way, we can quantify and try to understand.

NEIL DEGRASSE TYSON: And you also commented that when it goes to the stratosphere, the spreading goes globally, so that when it does come out as acid rain, it's way more dilute than would otherwise be the case if it was just in the troposphere.

DANIELE: Yes. And these things we have started to research. So I— do reach out if you want. I can point you out to the papers, to the international assessment we started writing on this. Look, we are trying to find out the answers.

NEIL DEGRASSE TYSON: So in the end of the day, it's not a perfect solution, it's a solution. And what the public needs to gain some comfort with is sensibly and rationally comparing risks. And so yes, the acid rain, it'll do this and do that. But if we don't do it, then this will happen over here. And that comparative risk is something I don't think we are good at, as as a civilization. And we can benefit much more with the teaching of statistics and probability in school.

If you grant me one conspiracy theory— will you grant me one? Thank you. State Lottery Funds. Do you know what most of the revenue from that goes to? Education. It goes to education. So I looked at the educational curriculum, kindergarten through 12, and nowhere is there a required course on probability and statistics. So as long as they don't teach it, you'll graduate thinking the lottery is a good way to get rich. That's my one conspiracy thing.

Everyone, please. Thank the panel. [LAUGHTER] Thank you all for coming. We will see you next year. We do this every year at this time. And the fact that a third of you had never come to one of these before, I don't understand. That disturbs me in some irrational way I don't know. Anyhow, we'll see you again next year. And the astronauts came back safely, if you were a late arrival to this event. Thank you all. Thank you all.

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