Enjoyed the episode? Want to listen later? Subscribe by searching 80,000 Hours wherever you get your podcasts, or click one of the buttons below:

The only argument against [nuclear energy] is a political one, that people won’t accept it, or people won’t want it. I don’t think there are any engineering or physics challenges that can’t be fairly easily addressed, and that includes the cost.

Mark Lynas

A golf-ball sized lump of uranium can deliver more than enough power to cover all your lifetime energy use. To get the same energy from coal, you’d need 3,200 tonnes of the stuff — a mass equivalent to 800 adult elephants, which would go on to produce more than 11,000 tonnes of CO2. That’s about 11,000 tonnes more than the uranium.

Many people aren’t comfortable with the danger posed by nuclear power. But given the climatic stakes, it’s worth asking: Just how much more dangerous is it compared to fossil fuels?

According to today’s guest, Mark Lynas — author of Six Degrees: Our Future on a Hotter Planet (winner of the prestigious Royal Society Prizes for Science Books) and Nuclear 2.0. — it’s actually much, much safer.

Climatologists James Hansen and Pushker Kharecha calculated that the use of nuclear power between 1971 and 2009 avoided the premature deaths of 1.84 million people by preventing air pollution from burning coal.

What about radiation or nuclear disasters? According to Our World In Data, in generating a given amount of electricity, nuclear, wind, and solar all cause about the same number of deaths — and it’s a tiny number.

So what’s going on? Why isn’t everyone demanding a massive scale-up of nuclear energy to save lives and stop climate change? Mark and many other activists believe that unchecked climate change will result in the collapse of human civilization, so the stakes could not be higher.

Mark says that many environmentalists — including him — simply grew up with anti-nuclear attitudes all around them (possibly stemming from a widespread conflation of nuclear weapons and nuclear energy) and haven’t thought to question them.

But he thinks that once you believe in a climate emergency, you have to rethink your opposition to nuclear energy.

At 80,000 Hours we haven’t analysed the merits and flaws of the case for nuclear energy — especially compared to wind and solar paired with gas, hydro, or battery power to handle intermittency — but Mark is convinced.

He says it comes down to physics: Nuclear power is just so much denser.

We need to find an energy source that provides carbon-free power to ~10 billion people, and we need to do it while humanity is doubling or tripling its energy demand (or more).

How do you do that without destroying the world’s ecology? Mark thinks that nuclear is the only way:

“Coal is a brilliant way to run industry and to generate power, apart from a few million dead every year from particulate pollution, and small things like that.

But uranium is something like a million times more energy dense than hydrocarbons, so you can power whole countries with a few tons of the stuff, and the material flows and the waste flows are simply trivial in comparison, and raise no significant environmental challenges — or, indeed, engineering challenges.

It’s just doable, and it isn’t doable with any other approach that you can imagine.

Renewables are not energy dense, so you have to cover immense areas of land to capture enough solar power through photovoltaic technology to even go a small distance towards addressing our current energy consumption with solar. And wind likewise.”

How much land? In Nuclear 2.0 Mark says that if you wanted to reach the ambitious Greenpeace scenario for 2030 of wind power generating 22 percent of global electricity and solar power generating 17 percent, wind farms would cover about 1 million square kilometers. That’s about as much as Texas and New Mexico combined. Solar power plants would cover another ~50,000 square kilometers.

For Mark, the only argument against nuclear power is a political one — that people won’t want or accept it.

He says that he knows people in all kinds of mainstream environmental groups — such as Greenpeace — who agree that nuclear must be a vital part of any plan to solve climate change. But, because they think they’ll be ostracized if they speak up, they keep their mouths shut.

Mark thinks this willingness to indulge beliefs that contradict scientific evidence stands in the way of actually addressing climate change, and so he’s aiming to build a movement of folks who are out and proud about their support for nuclear energy.

This is just one topic of many in today’s interview. Arden, Rob, and Mark also discuss:

  • At what degrees of warming does societal collapse become likely
  • Whether climate change could lead to human extinction
  • What environmentalists are getting wrong about climate change
  • Why political and grassroots activism is important for fighting climate change
  • The most worrying climatic feedback loops
  • And much more

Get this episode by subscribing to our podcast on the world’s most pressing problems and how to solve them: type 80,000 Hours into your podcasting app. Or read the transcript below.

Producer: Keiran Harris.
Audio mastering: Ben Cordell.
Transcriptions: Zakee Ulhaq.

Key points

Our Final Warning

I conceived and wrote [the book] actually as a big, giant spreadsheet really, where I’m putting together everything in the climate impact literature and attaching it to the relevant degrees of warming. So I can answer the question of what happens at two degrees. Actually, what happens at one degree is what we’re seeing around us. Because we’re already in the one degree world. So we can talk a bit more about that. And also just to tell the story of what happens if global warming continues to accelerate, and then we don’t succeed in mitigating it. And if we go rocketing past two degrees, even three degrees, where we end up and what kind of world we would be inhabiting then.

So you mentioned four to six degrees. This is a world where it becomes too hot biologically for humans to survive in substantial parts of the tropics and subtropics. So North Africa, the Middle East, South Asia. So that’s India, Pakistan, Bangladesh, parts of China, Indonesia which, coincidentally, all these areas host the majority of the world’s population currently. And it would be biologically intolerable. Basically, we’ve begun to make a large area of our most populated area of our planet uninhabitable. And then at the same time, we’d lose a lot of food production, again, because crops can’t survive either in this kind of heat and also the drought associated along with it. But we’d long since have lost the Arctic ocean ice cap, most of the world’s mountain glaciers, and a good proportion of the species that currently exist on the planet alongside us. So it would be well into a geologically defined ‘mass extinction’.

The most useful things that humanity has done to reduce climate change so far

The invention of nuclear fission was probably a key one. It wasn’t intended for that. Obviously it was intended to make bombs initially, and then was intended to make electricity. And was always seen as being environmentally terrible. It turns out that’s not the case and that will, and I’m sure we can talk about this, require an ideological mind shift amongst environmentalists more than anyone.

But we have made great strides with renewables. Bringing down the cost of solar panels means that solar is now probably the cheapest technology in most developing countries, which means you can get quite rapidly to zero carbon electricity in many places that don’t even have access to modern energy at the moment, which is great.

We’ve got lithium ion batteries which allow the electrification of a lot of transport. I’ve got an electric car. That wouldn’t have been possible even two or three years ago to get the mileage that it’s now delivering. And so you can sort of see the contours of a post-carbon landscape, which wasn’t the case when I started out. You had to just believe and hope that things would be invented, which now look like they can be part of the solution.

Worst case scenarios

I remember when some spokespeople were in the media saying, “Billions are going to die in the next 10 years.” And I think it was Andrew Neil actually might be, who in the interview said, “Well, how? What’s going to happen that’ll kill all these people?” And they weren’t able to answer.

So it’s one thing to have an apocalyptic fear and another to actually try and think through what the mechanisms are which would actually kill people if that’s what you’re concerned about. What kills people? Thirst kills people. War kills people. Anger kills people. People die because of lack of shelter.

So it’s different degrees of civilisational collapse. I mean, conflict/war is a civilisational collapse in a way, particularly if it’s essentially worldwide. So to me, I think the most concerning scenario is one where you can’t produce enough food to sustain the world’s population, which is a lot higher. We learned that by 2050, the latest UN figures are 9.7 billion by 2050. But you have to have pretty much doubled the world’s food supply at the same time, as you’ve got less and less of the world’s land being able to produce because of the combined impacts of heat and drought. And obviously, plants can’t grow without water. Lots of plants can’t grow if it’s too hot.

Arguments against nuclear energy

The only argument against is a political one, that people won’t accept it, or people won’t want it, so nothing to do with engineering. I don’t think there are any engineering or physics challenges that can’t be fairly easily addressed, and that includes the cost. Yeah, nuclear is very expensive at the moment, but that’s because it’s trying to satisfy safety concerns, which are taken vastly more seriously than any other type of infrastructure projects, and therefore require multiple redundant safety approaches, which cost a huge amount. You’ve got to build, I think, the EPR reactor at Hinkley… They talk about it’s like building a cathedral inside a cathedral. That’s the kind of engineering which we’re left with to try to reassure the public that this isn’t an existential threat. What’s that? That’s not engineering. It’s a psychological challenge. It’s a political challenge. The only way that I think it’s wrong is if people won’t accept it, and we waste time trying to do it instead of simply paving over whole countries with solar panels, if that’s the only way that’s mostly acceptable.

No one in the nuclear industry would ever say “Let’s save costs by reducing our safety components”. But those of us who are not in the industry can say, “Well, look. Why is it that nuclear has to fulfill this safety concern vastly more than anything else?” Cars aren’t that safe. Nothing’s that safe.

Not only coal, but even wind and solar aren’t that safe in terms of numbers of fatality per gigawatt hour, or however you want to quantify it. People fall off roofs putting solar panels on, and wind turbines fall apart and whatever, so nothing’s completely safe. Even in the worst case scenario, nuclear accidents, at least with the type of technologies we’re using, I wouldn’t use Chernobyl because that’s not the kind of reactor that we’ve got built anywhere else. But say Fukushima in Japan, which was about the worst, like a triple meltdown in the context of a much wider natural disaster, that’s about as bad as it can get. How many people died from radiation? Zero. That’s not even on the same scale as Piper Alpha, where the oil rig blew up and killed 150 people, or any mid-range industrial accident.

GMOs

If you want to be in a situation where food crops can still grow in a hotter, drier environment, you’re going to have to change their genetics. How are you going to change their genetics? Well, you’ll need to use genetic engineering. This isn’t complicated for people who understand. And so, yes, GMOs maybe could buy us a decade or two in terms of avoiding the supply shortages that might otherwise arise from low to moderate levels of warming. And also they can make, and are making agriculture more sustainable. If you’ve got insect repellent crops which fend off insect attacks, then you don’t need to spray them with insecticides.

There are crops which are disease resistant. So in Uganda, where I was a few years ago, they’ve got a big problem with bacterial wilt in the staple banana crop. There’s GMO varieties of banana already beyond the lab. They’re already in field trials, which could solve that problem basically. But because their GMOs, you’ve got this huge fear mongering campaign which is fully supported by Western aid agencies and NGOs, which has basically blocked up the political process in Uganda so that they probably won’t ever be released. Well done Westerners. You managed to stop Ugandans having disease-resistant bananas. Big round of applause for everyone, I think.

Articles, books and blog posts discussed in the show

80,000 Hours problem profile on climate change (extreme risks)

Mark’s work

Everything else

Transcript

Rob’s intro [00:00:00]

Robert Wiblin: Hi listeners, this is the 80,000 Hours Podcast, where each week we have an unusually in-depth conversation about one of the world’s most pressing problems and how you can use your career to solve it. I’m Rob Wiblin, Director of Research at 80,000 Hours.

It’s taken us too long to do an episode focused on climate change, but I’m delighted to say this first one is with Mark Lynas — one of the most independent-minded and forthright environmental activists I’m aware of.

Relative to many people we at 80,000 Hours are much more concerned about climate change, because we see it as having tail risks that could ruin the future of humanity. Its negative impacts could be very long-lasting and we’re concerned about how things go now just this century but for the entire future.

But in other ways, we can sound less concerned — partly because it’s already among many people’s top concerns, and we want to draw attention to the most neglected problems that haven’t broken through to the mainstream yet.

In preparing for this interview Arden and I wanted to learn more about the impacts climate change would have, the likelihood of it posing an existential risk, and help get ideas for which careers would do the most to actually limit climate change to tolerable levels.

In his books and this interview Mark was able to deliver on all 3 points.

For the first 35 minutes of the episode we largely just let Mark lay out his views. After that we debate some apparent disagreements, starting with the chapter titled ‘Where 80,000 Hours is at on climate change’.

Regular listeners will know that we usually let guests say their thing for a while at the beginning of episodes.

I don’t like immediately jumping in with objections before they’ve explained where they’re coming from. But in this interview as every interview, that doesn’t mean I agree with everything that’s being said.

More generally, these interviews are unusually long, but they’re still only long enough to meaningfully object to a handful of things that guests say, so I can never follow up on everything I’m not convinced by.

The rest of the team thought the second half of the episode, dealing mostly with the prospects of nuclear energy, was especially interesting. If that topic excites you the most, you might want to skip ahead to 1 hour and 26 minutes in, or select the chapter called Nuclear 2.0.

As part of our efforts to improve our climate change content, earlier this year Arden made a medium-sized update to our problem profile on the website, adding more discussion of long-range climate forecasts and the most extreme risks. You can find that at 80000hours.org/problem-profiles/climate-change/.

One final thing, unfortunately Mark’s sound for this episode isn’t up to our usual level. Like so many people these days, all 3 of us in this episode were recording from home, which meant we didn’t have our usual setup. Mark had to take the call from his car so he didn’t bother his family.

It’s not too bad, but if you prefer you can read the interview on the website, where we have transcripts of every episode. You’ll find a link to that in the show notes.

Alright, without further ado, here’s Arden and me interviewing Mark Lynas.

The interview begins [00:03:40]

Robert Wiblin: Today, I’m speaking with Mark Lynas. Mark is a journalist and author of several books on the environment, including “Six Degrees: Our Future on a Warming Planet”, “The God Species: Saving the Planet in the Age of Humans”, “Nuclear 2.0: Why a Green Future Needs Nuclear Power”, and ” Seeds of Science: Why We Got It So Wrong On GMOs”. As a green activist, he evolved from a more traditional desire to minimize humanity’s influence on the planet to believing that humanity’s enlightened stewardship of Earth’s environment is the only way to avoid disaster.

Robert Wiblin: He’s also gone from being an active campaigner against nuclear energy and genetically modified food crops to a vocal advocate in favor of both, as technologies that are good for the environment, at least if used sensibly. This year he published a fully updated version of “Six Degrees”, which aims to outline in detail the effects that different levels of climate change would have on nature and humanity. When he wrote the original in 2007, it won the prestigious Royal Society Prizes for Science Books, was translated into 22 languages, and adapted into a National Geographic documentary. Mark is also certainly a man of the world because he was born in Fiji, grew up in Peru, got a degree in History and Politics from the University of Edinburgh and is now a Visiting Fellow with a pro-science advocacy group at Cornell University. Thanks so much for coming on the podcast, Mark.

Mark Lynas: Thank you, Rob. Nice to be here.

Robert Wiblin: And I’m joined again today by my colleague Arden Koehler, who spent some time updating our article on climate change earlier this year. Welcome Arden.

Arden Koehler: Hey, great to be here.

Robert Wiblin: All right. So Mark, I hope to get to talk about your views on nuclear power and how likely climate change is to pose an existential threat to humanity. But first off, what are you doing at the moment and why do you think it’s really important work?

Mark Lynas: Right now I’m actually involved in two different areas of advocacy if you like. Well, three if you count the broader pro-science work I’m doing with Cornell. One of those is in trying to build a pro-nuclear grassroots movement, which seems like a strange idea, right? People mostly think of nuclear as this big military-industrial complex thing that governments do. But actually, for nuclear to be part of addressing climate change, which I’m sure we can talk about later, you’ve got to have sustained grassroots political support. So getting people who’ve been involved in Extinction Rebellion and direct action for climate activism, and to put all that energy and exciting enthusiasm into something which is actually a solution is really key.

Mark Lynas: I’m also involved in doing work with rewilding Britain. So actually to get more of our land areas devoted to a wilder landscape with better biodiversity and climate results. And, as I was saying earlier, broader pro-science activism with the Cornell Alliance for science, which is particularly important right now in the COVID situation. Because, to give you an example, even if we get a vaccine, if the anti-vax lobby is successful, then not enough people will take it to get herd immunity. So we’ve got to keep fighting the battles for science and evidence across the world because we’re currently in a dangerous situation, I think, where fewer and fewer people are trusting science, trusting evidence and expertise, and more and more people seem to be going for populism and conspiracy theories.

Robert Wiblin: Yeah. I know you’ve had a hand in a lot of different advocacy issues and I guess environmental issues over the years. How did you end up focusing primarily on climate change?

Mark Lynas: Well, I don’t know climate change was my earliest interest actually. I remember even when I was doing GCSEs, so back in… God, I don’t know, 1932 or something… I mean, a long time ago now. What am I, 47? So I was probably doing my GCSEs in the late eighties. But I remember doing a project on the greenhouse effect as it was called then and I launched my freelance career around climate and writing my first book, which was called “High Tide”. And I started doing that back in 2000 and I was traveling around the world. I went to Alaska, I went back to Peru, I went to Tuvalu, looking at the impacts, visual impacts of climate change and how people were experiencing them which, at the time, was novel, believe it or not. Now this stuff happens every day. But at the time, people didn’t believe that climate change was actually happening. It was seen as something which was possibly going to happen in the future. So yeah, that’s 20 years ago now.

Our Final Warning [00:07:40]

Robert Wiblin: Alright. Well, speaking of which, let’s dive into your new book, “Our Final Warning”. Maybe you can kick us off with a quick summary of what you say in the book? Maybe particularly focusing on the four to six degree warming scenarios, which I think will have newer ideas for people.

Mark Lynas: Okay. Well, the book is really just a structure… I conceived and wrote it actually as a big, giant spreadsheet really, where I’m putting together everything in the climate impact literature and attaching it to the relevant degrees of warming. So I can answer the question of what happens at two degrees. Actually, what happens at one degree is what we’re seeing around us. Because we’re already in the one degree world. So we can talk a bit more about that. And also just to tell the story of what happens if global warming continues to accelerate, and then we don’t succeed in mitigating it. And if we go rocketing past two degrees, even three degrees, where we end up and what kind of world we would be inhabiting then.

Mark Lynas: So you mentioned four to six degrees. This is a world where it becomes too hot biologically for humans to survive in substantial parts of the tropics and subtropics. So North Africa, the Middle East, South Asia. So that’s India, Pakistan, Bangladesh, parts of China, Indonesia which, coincidentally, all these areas host the majority of the world’s population currently. And it would be biologically intolerable. Basically, we’ve begun to make a large area of our most populated area of our planet uninhabitable. And then at the same time, we’d lose a lot of food production, again, because crops can’t survive either in this kind of heat and also the drought associated along with it. But we’d long since have lost the Arctic ocean ice cap, most of the world’s mountain glaciers, and a good proportion of the species that currently exist on the planet alongside us. So it would be well into a geologically defined “mass extinction”. How’s that sound?

Arden Koehler: Was that talking about all of the four to six range? Or were you thinking that was more at the top of that range?

Mark Lynas: No, that’s at the bottom.

Arden Koehler: That’s the early part.

Robert Wiblin: Alright, well maybe scare us some more with what happens at five and six?

Mark Lynas: Well, it’s difficult to know for sure, because a lot of the computer models don’t go up that high because… I don’t know why not really, it’s almost like the scientists don’t even want to know. So I ended up, in terms of the research for the book, going looking at palaeoclimate. So looking back at previous, what’s called megathermal, so really hothouse periods in the Earth’s geological history. And these were times when there was no ice on the planet at all. When CO2 levels were much higher. You can go up to places of the high Canadian Arctic, and there’s fossilized trees, so there was actual forest growing, and on Antarctica as well.

Mark Lynas: So a completely different world really which it’s difficult to imagine human civilization surviving in. I mean, most of the planet was too hot, so there were mass extinctions. So a lot of the previous big five mass extinctions that have happened have been associated with very rapid degrees of warming. And it’s possible if we really, really were really stupid, to begin to extinct life on Earth completely. This, more or less, it’s like a Venus effect. What happened to Venus is that the greenhouse effect was… Because it’s closer to the sun obviously, the greenhouse effect went on uncontrolled and the oceans essentially boiled off. And then you got left with a dead planet. And some of the computer models, it’s interesting to see how, if we burned all of the fossil fuels on earth, so drilled out all of the oil and gas and dug up all of the coal, I think we would be perilously close to that kind of a scenario.

Arden Koehler: Okay. So I think we’re going to return to the possibility of extinction and the idea of large swathes of the Earth becoming too hot for humans. But before we do that, just covering the current landscape so far, how much do you think we’ve reduced expected warming, based on our efforts so far? Relative to if we’d really done nothing?

Mark Lynas: We’re not quite on a, “do nothing business as usual trajectory” as was seen possibly as a worst-case scenario 10 or 20 years ago. Just in the UK, we’ve more or less stopped burning coal for our electricity grid. That’s the first time since the industrial revolution that the UK hasn’t been dependent on coal burning. What we need now is for China and India and other countries, which are still on the upward trajectory, to get off coal earlier rather than later. But the worst case scenarios, which take you to a 4,5,6 degree outcome require us to… We’d have to carry on, we’d have to burn like four times as much coal as we are doing today. So there’s no peaking in emissions really throughout the whole century. How realistic is that? It depends really on your reading of politics. There’s plenty of coal out there to burn. So it’s really up to humanity how far we want to push that lever if you like.

Robert Wiblin: If we did nothing or nothing more at least than we’re doing right now, I guess how likely are these kind of high-degree warming scenarios? Maybe I’m thinking more about, what’s our uncertainty about the… What’s the term for it, the “climate elasticity” or the “temperature elasticity” to carbon dioxide?

Mark Lynas: Well, the thing is, it’s not about doing nothing. It’s about doing something. And doing something is burning hundreds of gigatons of carbon, which would be an active choice for us to make. One of the interesting pieces of research which was done, I think it was a couple of years ago now, a paper published in Nature, looked at the current infrastructure around the world.

Mark Lynas: So all of the stuff, the industry, the cars, the power stations, all of that stuff, which has already been built, if it gets to the end of its lifetime, what would be the resulting cumulative carbon emissions from that? And it’s about 450 gigatons, which is the entirety of our 1.5 degree budget. So we’d blow through that in 10 years. And so it is unlikely that we’ll be able to get back onto that scenario. And if you say, “Okay, well we’re going to accept two degrees as a result”. Well, that’s when you lose the Arctic Ocean ice cap; that’s when 10 million people are flooded by sea level rise. That’s when you see droughts and heat waves really becoming lethal across large areas of the world. So my point is really that, it’s not the three and four degrees that we should be scared about, it’s the difference between 1.5 and two. And that’s where I’m really focused.

Most worrying feedback loops [00:14:00]

Robert Wiblin: What are some of the potential feedback loops that you’re most worried about and think that people should be aware of? Like positive feedback loops, where warming causes more warming?

Mark Lynas: Yeah, so positive feedbacks are wildcards in the system in that the result doesn’t become immediately dependent on our emissions. It becomes dependent on other things. So positive accelerations if you like. And there’s different kinds of feedbacks. One of the best known, I think, and the most likely, Is that if you melt the permafrost in the Arctic, so all of that frozen ground, it basically rots and releases both CO2 and methane, which is a much more powerful greenhouse gas. And that then of course delivers an extra jolt of warming into the system, which could then melt more permafrost. And so, there’s an element to which it becomes a self-reinforcing spiral.

Mark Lynas: Another slightly different feedback is that if you remove the Arctic ice cap, so all of the sea ice that’s at the North pole basically, in the summer months the sun’s heat, well the sun’s radiation that was otherwise being reflected by that very bright, shiny ice gets absorbed by the ocean. And that’s quite a significant change in the Earth’s energy budget. So it’s a bit like if that happens for two or three months, it’s a bit like fast-forwarding global warming by another quarter century. So this is why I keep saying that we need to stay within this 1.5 degree trajectory because the further you go past it, the more likely some of these feedbacks are to happen and the more difficult it then becomes to restrain the ultimate warming outcome.

Arden Koehler: I guess also as you go past these much more studied scenarios, you get a lot more uncertainty about whether there are any feedback loops that can be triggered. So it’s more possible that there could be these really bad outcomes that we don’t foresee?

Mark Lynas: Yeah, that’s true. We don’t know really at what level the Amazon rainforest ceases to be viable. And there’s been different estimates of that in the literature over the last 10-15 years. It was thought to be two degrees for a while, then three, and then four, and now it’s gone back down to three or even two again. And there’s also the issue of direct deforestation that you’ve got, obviously an idiot president there at the moment who wants to deforest as much of the Amazon as possible. And we’re already perilously close to the possible tipping point where that ecosystem becomes non-viable, because once you remove a certain portion of the forest, you don’t get the rainfall anymore because the trees aren’t transpiring the moisture that’s needed. And if you add some warming into that picture, you potentially get an accelerating or even a catastrophic fire season where most of the forest actually burns, which is one of the scenarios I paint in the book which is scary, not just for the climate, but there goes up in smoke, a substantial proportion of the Earth’s biodiversity.

Arden Koehler: So talking about our uncertainty at how things are going to go at these higher levels. It seems like one point that people have emphasized a lot, and very rightly, is that there’s scientific consensus that climate change is real and man-made. So I looked a little bit into what the scientific consensus seemed to be on what would happen at some of these higher levels of warming and how much temperature rise is expected from different levels of emissions, especially at these higher ends that you were talking about before, and I realized that there’s still a lot of uncertainty, or at least I think there’s still a lot of uncertainty on those questions. So, I guess I have a couple of questions for you about that. One, why do you think that is? There doesn’t seem like there’s been as much scholarship on some of those more extreme scenarios. And then also, given this uncertainty, do you think it’s possible that we’ll be wildly wrong? Like climate change could be way, way worse than we think it’s going to be or less bad?

Mark Lynas: Well, uncertainty is uncertain rather by definition. So it’s often quantified to the extent you get a kind of probability. I think it’s called probability density, function, a PDF. One of those… It looks like an upturned bell, but with a fat tail at the end. And the fat tail is the extreme outcome type probabilities. And so it could even be higher than six degrees. So I actually do try and quantify that in the book a bit, in the Six Degrees chapter and talk about what the likelihood is, if we do continue to increase our emissions, what are the scenarios where we could actually deliver a really serious collapse of civilization, mass extinction type outcome?

Mark Lynas: And I come in that it’s somewhere between 1/100 and probably 1/10 even, if we’re both unlucky and stupid. Which is, you wouldn’t go on a plane with that level of probability of it crashing, but we somehow seem perfectly happy to tolerate that for our home planet which says something strange about the sort of collective diffusion of responsibility that we seem to be able to feel when it’s something that affects all of us. We don’t take individual responsibility. So I don’t know, there’s always a chance that it could be much worse than you expect. But there’s also the chance it could be much better. At the moment, the rate of planetary warming is more or less as the models projected, and have projected more or less consistently since the 1980s. So the scientific consensus seems to be more or less, at the moment, being born out by what we’re seeing.

Arden Koehler: So just to make sure that I have what you said, did you say between 1/100 and 1/10th chance of societal collapse or extinction if we get to six degrees? Or all things considered?

Mark Lynas: Well I think societal collapse and extinction would happen a good deal earlier. I think that’s a significant risk at three and 50/50 odds on at four and highly probable at five and almost certain at six. But that kind of stuff is always speculative. It could be better than you think. For example, even though we know that extreme weather events are getting worse, they’re getting more extreme, you’re getting heavier rainfall, stronger hurricanes, fewer people die in them and that’s because we’ve got better sheltering arrangements, better evacuations, more warnings, that kind of thing. So it doesn’t necessarily follow that because the weather’s becoming more extreme, that it kills more people. And so there’s always the human adaptation aspect of things, which means that you can’t just make linear projections for where things are now and where things then end up with a certain amount of warming.

Why people are reluctant to talk about worst case scenarios [00:20:11]

Robert Wiblin: Something that was new to me in the book is that you think that scientists or that people at the IPCC, they seem reluctant for some reason to truly analyze the five degree or six degrees scenarios. And for that reason, the research on it is a bunch hazier and you kind of had to do more of the legwork there yourself. Why do you think it is that they don’t want to talk about those possible outcomes?

Mark Lynas: Yeah, again, I can only speculate, but it did definitely jump out at me from the literature – just the absence of studies on what the five degree or six degree worlds would even look like. It’s hinted at in some of the palaeoclimate stuff, like an introduction to a paper on permanent mass extinction might say, “Well, this bears some resemblance to possible end of the century scenarios”, but that’s as far as they’d go. And given that six degrees has been in the modeling envelope since the 1990s, I think it’s extraordinary that scientists haven’t put more effort into actually telling us what the worst case scenarios might look like given that they’ve spent… There’s probably thousands of papers about 1.5 degrees, which is equally unlikely, given how much emissions are still rising every year. So it’s like nobody wants to tell a really bad news story, I think.

Arden Koehler: I guess they could think that we have time before then to think about those worst-case scenarios? I mean, I’m not saying this is necessarily a good reason because of course you think it’s actually relevant now what the worst case scenarios are, but they might think, “Well, we’ll do that next year”.

Mark Lynas: Well scientists aren’t going to think that because they know that the eventual warming is a function of cumulative emissions, so it’s a budget. You can rocket through the budget in the next two or three decades. So it’s not a case of… This is the mistake we make when we think about emissions trajectories in terms of percentages. You think, “We’re 70% below where we are in 1990”, I mean that all that stuff is actually a distraction. It doesn’t tell you anything about where you’re going to end up in terms of the resulting warming. But I do think there’s a scientific reticence. That term was actually used by Jim Hansen who’s now retired, but he was with NASA for a long time. Probably one of the best known climate scientists around the world.

Mark Lynas: And he spoke about that too. And I think scientists don’t want to be called alarmists. They’ve got to think about the next grant funding. It’s a very politicized issue, particularly in the U.S., if you get a reputation for being an alarmist climate scientist, that might well harm your future career prospects. And also scientists by nature are very cautious. They don’t want to say something which seems extreme and seems ill-considered in some ways. So I think that the idea that some skeptics have that the scientific communities are ringing alarm bells all the time is really the opposite of what’s happening. Most of the time, the scientists are quite reluctant to say anything which goes beyond what they’re most confident about.

Robert Wiblin: Yeah. I understand the reasons, it does just seem to me incredibly negligent because if you add together… Sometimes people say uncertainty is a reason not to do very much or they imply that. In the case of climate change, it just seems like uncertainty is an absolute curse for us. Because once you add together our uncertainty about how many emissions we’re actually going to produce over the next hundred, 200 years, and then, put on top, our uncertainty about how much the climate responds to those emissions, and then add on top X factors that are unknown, or these positive feedback loops, the tail issue, the probability of getting five or six degree warming just doesn’t seem that low. And I think even in the IPCC reports, they don’t say that it’s especially low. But then they just don’t want to follow through on what that implies about what we should be looking into and how worried we should be.

Mark Lynas: I couldn’t agree more. And in fact, again, I say that in the book, because if you think of how many billions of dollars get invested in trying to make aircraft that little bit safer, that might save a few hundred lives a year at the absolute most, in terms of the numbers of plane crashes there are or would have been with slightly less safe aircraft, and we won’t invest even a hundredth of that in answering the question of what the worst-case outcomes could be for the planetary biosphere it is extraordinary. I completely agree.

Arden Koehler: I feel like one thing that… This feels relevant to me here, is that a lot of the worst effects would affect future generations, whereas in the case of the plane, these are going to affect people in the next five years, 10 years. So it seems like on the one hand, people are less likely to worry about effects on future people than they are on present people. But I guess I also feel unsure about how much some of these effects of climate change are likely to affect people who are alive today. Do you have a sense of that?

Mark Lynas: Yeah, well I think people are reluctant to face any dangers which necessitate a change in lifestyles however immediate, actually. I don’t think it’s the case of just kicking the can down the road to the next generation. You can see that with COVID and with how reluctant political leaders were and societies and people generally to even adopt the smallest changes like wearing masks and things. People are very reluctant to do anything which changes their daily lives.

Arden Koehler: Although we were much less reluctant when it came to COVID. I mean, the amount that people have changed their lives in response to COVID is much greater than in the case of climate change.

Mark Lynas: Well, it’s proportionately greater perhaps to the speed at which the danger becomes apparent. If you can be infected with something in the next five days and dead within three weeks then yes, it’s obviously a bit different to a 30 year trajectory where you’re not really certain about how you personally will be impacted by something like global warming. But that’s why I wrote the book, to try and bring home these impacts and to make it clear that nobody is spared if we allow climate change to carry on accelerating.

Arden Koehler: I guess you say nobody is spared. What about people who are middle-aged today? Are they spared from severe effects–

Mark Lynas: If they die anyway.

Arden Koehler: Yeah, or if there’s not going to be severe impacts in the next, let’s say 40 years. I’m just curious if you think in fact there is?

Mark Lynas: I don’t know. We’re seeing fairly extreme impacts already. If you lived in Australia last summer and the sky was red and your house is in urgent danger of burning down. Same in California: a whole town was wiped out, ironically called “Paradise”, and there was… I can’t remember the death toll, but it was in the hundreds. And so there’s a non-negligible chance that you will even be killed by climate related impacts in today’s world. And that’s obviously going to carry on accelerating. The thing is, people’s lives are full of risks of course. Every time you get behind the wheel and drive, or pretty much everything you do or whatever you eat, maybe that’s going to raise your risk of cancer or something. Not eating will raise your risk of starvation. So either way you’ve got to do something.

Mark Lynas: So we’re all used to juggling different types of risks. And yes, I guess… I’m sure you’re right that risks which can be put off into a long time in the future are less likely to engender a sense of sacrifice today. It’s a bit like, would we all go into lockdown for a pandemic that was going to happen 30 years in the future? Alright, probably not.

Robert Wiblin: That might be a tough sell.

Mark Lynas: Yeah but that’s why we need scientists to inform policymakers so that we can actually make collective changes. And they don’t have to be sacrifices either. This is why I support nuclear power and things which can actually continue to deliver large amounts of energy and modern lifestyles that we all say we want, without frying the planet. So you’ve got to try and think of a way through that’s going to allow us to solve the problem in a politically realistic sense.

Robert Wiblin: I guess one generic concern I have as a consumer of the science here is that, I suppose, this is a bit ironic given I was saying that I wish scientists would be more alarmist in some ways. But I worry that the literature might be a bit biased towards worrying more because if you’re a scientist studying climate change, you’ll almost certainly be worried about it yourself. And you’d rather publish another paper that suggests it’s a problem that we need to do something about it rather than one that suggests that, well, maybe it’s not actually so bad and people shouldn’t worry as much because that feels irresponsible. It feels negligent to calm the public down about this. And I guess we see these kinds of publication biases in social science or all the time where the more you study a question, the more it seems like the thing that people were saying was the case just becomes… The effect becomes attenuated. Do you worry that there could be biases in what kind of things get published in Earth Sciences about climate change?

Mark Lynas: I think, yes, there’s probably a bias towards not publishing papers which simply confirm the null hypothesis , i.e., you actually have something worth saying. A lot of the time, when you carry out a scientific study, you find out that your hypothesis is wrong and actually nothing’s happening or nothing interesting is happening, but you don’t publish those. This is actually more of an issue in medicine isn’t it where if you’re doing a drug trial and you find out the drug doesn’t work, you don’t publish, which is why they’ve tried to combat that. Because that then does lead to a bias throughout the literature in terms of how it reflects reality, if you like. So no, I think there’s probably that in climate as well. But I think it’s probably counterbalanced by what we were talking about earlier, which is the reticence to look alarmist as well.

Arden Koehler: I think Rob was asking, correct me if I’m wrong, not about papers that confirm the null hypothesis or what we already thought or something, but things that actually disagree with other papers that say that it’s less… Maybe we’re going to see less warming from a certain degree of emissions?

Mark Lynas: Oh, you mean in time in terms of challenging groupthink?

Arden Koehler: Well, not necessarily calling it groupthink, but just coming to a conclusion that should make us less worried about some climate outcome than we would have been just based on the scientific consensus before the study?

Mark Lynas: No, I don’t really think so. Having seen scientists in action, as I’m sure you have as well, they love to disagree with each other. They love to undermine and challenge each other’s work. And I think that sense of… Even on the most finickity point as well. So you often see, don’t you, letters into the journal, “Oh they’ve got some calculation wrong”. So I think actually… And there’s so much diversity as well. Take the work of Roger Pielke Jr., who’s spent much of his career actually trying to normalize hurricane damages and trying to find out whether there’s a climate signal in the amount of damage that’s being done in the US or elsewhere from hurricane impacts and find out if you account for economic growth and the more infrastructure in coastal areas, actually there isn’t a signal that you can see.

Mark Lynas: That gets picked up by climate deniers and they go, “Look, hurricanes aren’t getting worse!” But it’s not even saying that. It’s actually saying hurricanes might well be getting worse, but that signal isn’t coming through with damages, once you account for economic growth. That kind of work actually, which I think is really rigorous and goes counter to the conventional green, you know how hurricanes were sort of adopted along with polar bears as the emblem of a climate impact. I think there’s a lot of challenge to that kind of thing. And it’s very healthy and it’s good scientific discourse that that happens.

The most useful things that humanity has done to reduce climate change so far [00:30:48]

Robert Wiblin: We’ll come back to solutions later on, but I’m curious just to ask at this point, what do you think are the most useful things that humanity has done to reduce climate change so far? Is there a handful of stuff that’s really moved the needle?

Mark Lynas: That’s a really interesting question. Well, I mean, the invention of nuclear fission was probably a key one. It wasn’t intended for that. Obviously it was intended to make bombs initially, and then was intended to make electricity. And was always seen as being environmentally terrible. It turns out that’s not the case and that will, and I’m sure we can talk about this, require an ideological mind shift amongst environmentalists more than anyone.

Mark Lynas: But we have made great strides with renewables. Bringing down the cost of solar panels means that solar is now probably the cheapest technology in most developing countries, which means you can get quite rapidly to zero carbon electricity in many places that don’t even have access to modern energy at the moment, which is great.

Mark Lynas: We’ve got lithium ion batteries which allow the electrification of a lot of transport. I’ve got an electric car. That wouldn’t have been possible even two or three years ago to get the mileage that it’s now delivering. And so you can sort of see the contours of a post-carbon landscape, which wasn’t the case when I started out. You had to just believe and hope that things would be invented, which now look like they can be part of the solution.

Arden Koehler: Yeah, that feels like a really important step forward, if it’s like we don’t just have hypothetical technologies, but have actual technologies.

Mark Lynas: Hydrogen has always been an example of a hypothetical technology. The hydrogen economy has been expected by enthusiasts since the 1970s and maybe even earlier, and it’s not happened yet. The cheapest way to make hydrogen, in fact, the way that almost all hydrogen is currently made is through reforming natural gas. So ripping the H out of CH4 and releasing CO2 as well.

Mark Lynas: So most hydrogen isn’t even green, it actually is a significant producer of greenhouse gases. So you’ve got to do better than that. You’ve got to produce hydrogen from zero-carbon sources, and you’ve got to do so more cheaply than it currently comes from fossil fuels. So the economics… So the physics isn’t really the issue a lot of the time. The technology is actually invented, it’s often the economics of making sure that they are cheap enough to be scalable outside the lab.

Robert Wiblin: One thing that maybe separates me from the people I speak to who think that we shouldn’t do that much about climate change is that I think that we could probably largely prevent climate change without it being that costly, just on a global economic scale because we have these technologies now like nuclear, solar power, wind power.

Robert Wiblin: I think if you just try to add up the total cost that it would take to replace most of the coal power generation that we have with renewable technology, I guess also just projecting forward the improvements or the cost reductions that we’re going to get in those technologies over the coming decades, it seems we can do this for 1 or 2% of GDP per year, over a couple of decades. Does that seem right to you, or do you think it might be more expensive than that?

Mark Lynas: It’s certainly more expensive than that if you go for 100% renewables, but I’m not even sure it’s physically possible with 100% renewables. I mean, I’ve spent the last couple of weeks actually looking at some of the figures on this. And if you were to try and just replace oil in a country like Korea or Japan, so a densely populated country without huge amounts of spare land, you have to take up a significant proportion of the entire nation with solar panels.

Mark Lynas: In the UK, I just did the figures about an hour ago actually, if you want to replace our oil consumption, you’d have to cover over one and a half times the size of Wales with solar just for oil; never mind about decarbonizing the electricity grid and all the rest of it.

Mark Lynas: So that’s not going to happen. It’s not going to happen for political reasons. It’s not going to happen because of land use conflicts. It’s not going to happen. Even environmentalists such as Greenpeace was against the latest big solar project in Cleve Hill, which is 350 megawatts in Kent, because they say there’s better alternatives and I’m like, “What are they?”

Mark Lynas: If it’s not solar which we’ve been campaigning in favor of rather for three decades, what’s the alternative, nuclear? I mean, you’re going to change your mind on that magic, tell us which one? So, we’ve got to get to more numerous, now to quote the late great David MacKay, approach to these issues.

Mark Lynas: And yeah, to come back to your point about economics and spending: the oil industry plans to spend, I can’t remember exact figures, but it’s trillions in terms of oil exploration and production in future decades to keep people well-hooked on liquid hydrocarbons. We’re currently consuming close to 100,000,000 barrels of oil a day. That doesn’t just come from nowhere, it costs a huge amount of money to explore and produce that.

Mark Lynas: And so that’s money which could be being redirected into not renewables only, but clean technologies across the board. And it’s certainly possible that those could be delivered at a net-zero cost, so it’s as cheap as keeping oil. And certainly, I don’t think it’s going to bankrupt the world to get off carbon.

Robert Wiblin: Yeah sorry, I think I meant to talk about the net cost, and I think that’s something that people will maybe miss is that we already spend a lot of money replacing electricity infrastructure, going and exploring for oil, and getting the oil, and building all of the plants to generate this electricity.

Robert Wiblin: And I just want to think about what’s the incremental cost to do that in such a way that we don’t produce terrible climate change. And there, if you think about that, it’s just that this seems well within humanity’s economic budget to do this. I don’t think it’s going to break the bank.

Mark Lynas: It might well be. So if you include nuclear and if you get nuclear to be cheap, which means you’d have to change the whole nuclear production process and make it modular, and make it scalable rather than having these great big concrete first-of-a-kind projects, which costs tens of billions. But if you can do that, and I don’t see any fundamental physics or engineering reasons why you can’t, you could probably deliver net-zero carbon at net-zero cost. That’s my guess anyway.

Where 80,000 Hours is at on climate change [00:36:34]

Arden Koehler: So as listeners can probably tell, Rob, and I, and 80,000 Hours more generally are pretty concerned with climate change and also very concerned with the possibility of extreme impacts, which might make people who are longtime listeners to the show, or are familiar with us, wonder why we don’t talk about it more on the show, or on the website.

Arden Koehler: So we’re actually in a tough spot when it comes to climate change and how we should talk about it. So relative to a lot of people, we’re more concerned about climate change because we see it as having these tail risks, these risks of extreme impacts that could decimate the future of humanity, and also because we care a lot about long-lasting impacts that can last indefinitely into the future, and not just things that happen in the short-term.

Robert Wiblin: And there’s also just so many cool, concrete things you can do, isn’t it? Electric cars, build nuclear power plants, advanced to solar R&D at a… Personally, I find it really, really motivating that it just seems it’s a problem that we really could solve if we put our minds to it.

Arden Koehler: Yeah so, I mean, there’s all these reasons to focus more on it. But then on the other hand, it doesn’t make this very short list of top problems that we talk about the most, and that’s for a couple of reasons.

Arden Koehler: First, it’s already among many people’s greatest concerns. So, I saw a survey recently that said that climate change and environmental destruction were rated by millennials as the most critical problems to solve in the world. And because we’re a really small group and we’re advising a comparatively small audience right now, we think it makes sense for us to focus on issues that are more neglected, so that’s including issues that receive less than 1% of the funding that climate change does. And we do that because we hope it means that people will be able to make more progress on those issues where there’s more low hanging fruit.

Arden Koehler: And secondly, while we agree that climate change is likely to be very bad and maybe even going to be a unprecedented humanitarian disaster if we don’t do something really quite drastic about it, we think it’s unlikely to lead to a collapse of civilization or human extinction. And insofar as that’s the case, it seems less likely to permanently affect humanity’s future for the much worse. And, at the same time, we think there are issues that do have the potential to totally destroy humanity’s future, and some of those are much more neglected issues.

Arden Koehler: So we think it makes sense for us to suggest that many of our audience members work on those right now. Do you have any just reaction to that general take?

Mark Lynas: Wow! Yeah, there’s a weird disconnect really between a lot of people saying that humanity’s number one challenge is climate change while, at the same time, it’s never your number one concern on any day-to-day level, or even on the list of political concerns. I mean, it’s now in the top 10 for most people’s political concerns, and it’s even been a major factor in elections in some countries, but it’s not really dominating the agenda in a way that will be necessitated if we were to really deal with it seriously.

Arden Koehler: Yeah, it was interesting. That seems right. But where do you think this disconnect comes from where a lot of people say, “This is the most important issue facing the world right now,” but then it isn’t at the top of political agendas?

Mark Lynas: I think it’s because it’s perceived as being hard. It’s not an easy thing to tackle. It’s perceived as being the property of a particular political constituency, mostly the Left and the Greens, and everyone knows they’re a bit mad. And so it’s seen as being a really expensive and really difficult thing to do, which is going to, potentially for politicians, lead to short-term political pain.

Mark Lynas: And you can see why that is, I mean, take Germany, good case study for how not to do climate policy-making. And the unfortunate thing with Germany is that they’ve got this combination of two really critical problems. One is that they’re highly dependent on coal and the dirtiest form of coal: brown coal lignite has mostly been extracted through opencast mining. So tremendously damaging to the landscape, to eradicating old growth forests, and medieval villages, and it’s just terrible.

Mark Lynas: But there’s a very strong coal lobby which is, this is an industry which employs tens of thousands of people and it has very strong union representation so politically, it’s a very powerful voice. So that’s the number one problem.

Mark Lynas: Number two is that this is a country, which is, for one reason or another, has become almost existentially angsty about nuclear and the Green party, which I think first came to power in Germany in 2000. Came on a platform of getting rid of the nuclear power stations. They didn’t care about climate change and they still don’t, to anything like the extent they care about getting rid of nuclear.

Mark Lynas: And so what’s that meant? It’s meant that they are going to keep coal on the grid until I think the latest political agreement was 2038. So these things are always a product of different political forces and cultural forces, and every country is a bit different. But it’s not just the obvious conventional bad guys like, ExxonMobil, or all the big names of the fossil fuel industry who are standing in the way of progress, it’s also Greenpeace. It’s also ourselves, in terms of our own biases and lack of ability to change our minds on key issues as the facts change.

Robert Wiblin: I’m not sure whether this should make us more optimistic or more pessimistic that it’s an issue that’s gotten a lot of attention for decades, and the vast majority of people think it is a real problem, and a decent faction of the population thinks it’s the most important problem, and yet, there’s so much that hasn’t gotten done.

Robert Wiblin: On the one hand, that could make you think, “Well, there’s so much potential to do much more than we’re doing now”. On the other hand, you might think, “Well, even if we do convince even more people that it’s the most important problem of our time, just nothing will continue to happen because there’s some other barrier or some other bottleneck”.

Mark Lynas: Yeah, but that’s because the problem isn’t solvable with the conventional green prescription, so it’s hardly surprising that it doesn’t get solved. If they say, “You’ve got to solve climate change with only using wind and solar”, where they themselves admit that wind and solar, well, they’re even against them when they’re proposed. So it becomes an insoluble problem, which is why I think it doesn’t get solved.

Mark Lynas: It’s not difficult to understand. So the conventional narrative of “We would have solved this 30 years ago if the bad guys in the fossil fuel industry hadn’t stood in our way”, I don’t think it’s quite right, actually, and I wrote this in my Nuclear 2.0 book.

Mark Lynas: I blame the Green Movement for at least half of cumulative emissions. If the nuclear power programs, which were proposed in the 1960s and ’70s had continued, then most of the world’s electricity would probably be zero carbon already, and then we’d only have to worry about the rest of it, the liquid fuels and stuff.

Mark Lynas: You can see that process taking place in the US where the anti-nuclear lobby stopped power plants which were then converted to coal. I mean, they just took the reactor place hole and put a coal furnace in there, and the environmentalists all went away and said, “Off you go”. And that happened over, and over, and over, again.

Mark Lynas: And they made the world safe for coal. That wasn’t the intention. It was all meant to be fluffy wind and solar, even back in the ’70s. But it’s physically a challenge now, but it was physically impossible then to do what they were asking for. So, whose fault is it? I’m agreeing it’s my fault too. I was anti-nuclear for all those years as well.

Probabilities of worst case scenarios [00:43:34]

Robert Wiblin: All right, we’ll come back to the nuclear issue later on. We’ve got a pretty big section on that because I really liked your book Nuclear 2.0. But for now, let’s move over into this issue of how likely it is for humanity to be able to avoid the worst possible outcomes of climate change, which is an area where I think we might disagree on the probabilities.

Robert Wiblin: Yeah, just recap us overall, how likely do you think it is that climate change will lead to the breakdown of industrial civilization as we know it today? And I guess secondarily, how likely might it be to effectively cause human extinction? And I guess probably those numbers are going to be pretty different, they’re two fairly different standards.

Mark Lynas: Yes. Well, for me the question isn’t quite in the way you framed it, the question is “At what degrees of warming do these outcomes become more likely?” I remember when Extinction Rebellion, some spokespeople were in the media saying, “Billions are going to die in the next 10 years.” And I think it was Andrew Neil actually might be, who in the interview said, “Well, how? What’s going to happen that’ll kill all these people?” And they weren’t able to answer.

Mark Lynas: So it’s one thing to have an apocalyptic fear and another to actually try and think through what the mechanisms are which would actually kill people if that’s what you’re concerned about. What kills people? Thirst kills people. War kills people. Anger kills people. People die because of lack of shelter.

Mark Lynas: So it’s different degrees of civilizational collapse. I mean, conflict/war is a civilizational collapse in a way, particularly if it’s essentially worldwide. So to me, I think the most concerning scenario is one where you can’t produce enough food to sustain the world’s population, which is a lot higher. We learned that by 2050, the latest UN figures are 9.7 billion by 2050.

Mark Lynas: But you have to have pretty much doubled the world’s food supply at the same time, as you’ve got less and less of the world’s land being able to produce because of the combined impacts of heat and drought. And obviously, plants can’t grow without water. Lots of plants can’t grow if it’s too hot.

Mark Lynas: I mean, you can push the thermal tolerance threshold of crops with genetic engineering to some extent, but there comes a point where enzymes get denatured and your plant will just die or certainly, and there’s a long time before that, yields will fall off, and so on.

Mark Lynas: So that’s, for me, the main question. And one of the most important studies I think that’s ever been performed on this was a study in the PNAS Journal, which looked at what they called synchronous collapse in breadbaskets around the world. So at the moment, the world still produces enough food every single year very reliably. We’ve never had a major food shortage which has been as a result of harvest failure.

Mark Lynas: So I mean, if the U.S. Corn Belt was knocked out one year, that would have a huge impact on food prices, and have a huge impact on food security, in fact, as a direct result of that. But imagine if it really wasn’t just the U.S. Corn Belt. It was Australia, it was Brazil, and Argentina, it was breadbaskets of Eastern Europe, and the former USSR, all of that added together, then you enter a situation which humanity has never experienced before, and which looks very much like famine.

Mark Lynas: So that, for me, that’s how I answer the question, how are people going to die? People are going to die from starvation if there isn’t enough food globally, and that’s one of the mechanisms. And when that happens, you can actually link with some degree of confidence to levels of climate warming.

Arden Koehler: So you said you wanted to, the way that you prefer to think about this is in terms of which temperature increases give us a good chance of these impacts. So do you have a guess at what degree of warming we would need to reach for the full-scale collapse of society, perhaps due to very, very widespread famine to have say a 10% chance of happening?

Mark Lynas: Oh, I think… You want to put me on the spot. I would say it has a 30 to 40% chance of happening at three degrees, and a 60% chance of happening at four degrees, and 90% at five degrees, and 97% at six degrees.

Arden Koehler: Okay. Okay. No, I appreciate you being willing to put numbers on this because I feel that’s always really hard, but it’s really helpful.

Mark Lynas: Maybe 10% at two degrees.

Arden Koehler: Okay, so we’re getting close to 10% already.

Mark Lynas: Yeah, but I think these early stages of warming, I mean, we’re at one degree now and obviously it hasn’t happened, so that’s a 0% chance of civilizational collapse unless it starts happening tomorrow. But the biggest impacts now have been our natural ecosystems. Remember, we lose 99% of the world’s coral reefs before two degrees, so that’s an entire biome wiped out.

Mark Lynas: And the same happens with rainforests and other important ecosystems, the whole Arctic tundra, and so on, fairly early on. And so humans are actually, and this is a bit of a truism, I mean, we’re a remarkably adaptable species. We’ve got all sorts of tools and technologies at our disposal. I mean, we can even deal with food production by using microorganisms and industrial baths. You know?

Mark Lynas: You have to have feedstocks like hydrogen and CO2 to put into those, but then you’ve completely delinked food production from climate. So there’s always, this is why I wouldn’t put 100% risk on civilizational collapse because there’s always the possibility that we can adapt our way throughout almost any imaginable scenario with the exception of turning the planet into Venus. But even then I suppose we can go off and terraform Mars, I suppose, and maybe a few hundred people can do that for a couple of decades until it doesn’t work out.

Mark Lynas: I don’t know. I’m indulging in spurious speculation now. But where does the synchronous breadbasket harvest failure come in? About four degrees. Where does this issue of biological and uninhabitability of large areas of very densely populated parts of the world? That’s about four degrees as well. So that’s why the numbers really go up at that level of warming.

Arden Koehler: Okay. Can I ask another really hard question asking you to put numbers on some things, just to get a sense of your views? So that was large-scale civilizational collapse. So long time listeners will know we’re especially interested in extinction risks at 80,000 Hours. So, can you answer for humanity going extinct? So what temperature are we 10% likely to go extinct at?

Mark Lynas: Well, to extinct humanity, you have to eliminate the last breeding pair, but it’s a big–

Arden Koehler: It’s a high bar.

Mark Lynas: It’s a pretty high bar when you think people can live in artificial environments giving them sufficient food for quite a long time. And we can live in environments, which are very… We can’t just say well, our habitable space is, I don’t know, average 14 degrees or something like, a particular species of tree, or reptile, or something. Because of our technologies, we can live in minus 40, we can live in plus 40 Celsius.

Mark Lynas: But, I suppose our resilience comes in the same way as our Achilles heel in that we are interdependent in incredibly complex societies which you can’t even understand. I mean they happen dynamically, but no one really knows how the economy works. And so this fantasy that survivalists have of being able to look after themselves and maybe their family in a protected fortress type environment: if you stockpile canned foods and the zombies don’t get you, you can do that for a decade or two, but–

Arden Koehler: Then extinction would just happen later if that was all it depended on.

Mark Lynas: Yeah. Yeah. But I do think that humans are one of the last species to go extinct on the planet, not one of the first because it’s just so obvious. A) There’s a lot of us, so to kill us all is going to take some doing. B) We’re incredibly adaptable and can live in all sorts of different environments.

Mark Lynas: We’ve got all of the technologies and we’ve also got advanced knowledge of these impacts, i.e., because we’re discussing them now, so we can avoid most extinction scenarios: we don’t even have to be that smart to do so. So I’m not too worried about the near to medium term prospects of human extinction. Yeah, I think there wouldn’t be much of any life left on the planet if humans were to fail to survive as well.

Arden Koehler: What about the long-term risk of extinction? So let’s say if we get up to six degrees, do you have a guess at how probable it is that we go extinct?

Mark Lynas: I think some humans would survive even at six degrees. You need to be in a situation where none of the planet’s surfaces are able to produce crops. Even at six degrees, you could produce crops up in the Arctic, or on the Antarctic Peninsula, or Alaska, or somewhere.

Mark Lynas: But if all of those places are too hot or you have to make the atmosphere unbreathable in some way, so you need to be into a runaway greenhouse scenario where you’re gradually transforming towards Venus, and the water on Earth, most of that ends up in the atmosphere and gives a very accelerated greenhouse effect.

Mark Lynas: That means you have to break down the structure of the atmosphere, you’ve got to destroy the tropopause weather. So in the troposphere now, as it gets colder higher up, the liquid water condenses and falls back as rain, and you have to stop that process happening so that liquid, the water vapor can circulate throughout the whole atmosphere, which is probably what happened with Venus.

Mark Lynas: But one of the ways to think about this is there’s this concept in solar systems of the habitable zone. The Earth of being in this Goldilocks zone where it’s not too hot and not too cold. Mars is too cold. Venus is too hot. In a way, it’s pretty clear that we’re very close to the inner edge of our habitable zone, so we’re a lot closer to a Venus outcome than a Mars outcome.

Mark Lynas: That maybe wasn’t the case a few billion years ago when we had Snowball Earth, and the atmospheric chemistry was very different, and the Sun was a lot fainter as well. So this combination of the more powerful Sun over geological time and the changing atmospheric chemistry means we’re quite close enough to it anyway, to what’s tolerable.

Mark Lynas: So the additional greenhouse effect that we’re creating is a bit like pulling the Earth closer and closer to the Sun, in terms of our orbit, which for me, is a good way of thinking about it. Every time you switch on your car, you’re taking us a centimeter closer to the Sun.

Robert Wiblin: So it sounds like we should mostly talk about the collapse of civilization cases because they seem substantially more likely, just because extinction is such a difficult thing to accomplish. But are there any ways in which we could end up with 12 degrees or 18 degrees warming that worry you, or you think they’re more than an incredibly low likelihood?

Mark Lynas: Yeah so that’s in a process of runaway. The surface temperature of Venus is 400 Celsius, I think. It might be a bit higher. So by that time, there’s no liquid water anywhere, and most of the carbon has moved from the lithosphere to the atmosphere, so you’ve got a 95% CO2 atmosphere, I think, on Venus. A very dense, very high pressure, and very hot indeed. It’s a long way between where we are on that.

Mark Lynas: And I guess, what’s also perhaps a guardrail is how hot has it ever been in terms of the geological past of the planet? As an average temperature difference, it may have been in the mid-Cretaceous as much as 10 or 12 degrees warmer than now on average, which is why most life was then at the Poles or certainly in the very high latitude.

Mark Lynas: The tropical oceans were 40 Celsius or so, so way, way too hot for most life to survive. You get reef gaps and they’re off the record where there’s no corals, very few marine organisms at all in those sorts of areas. But the Earth survived that before with a fainter Sun, and with a slightly different atmospheric chemistry with a fully functional carbon cycle.

Mark Lynas: What’s perhaps scary now, in terms of a geological parallel is the rate at which we’re forcing the system. So we’re transferring carbon from the lithosphere, so from the rocks, the subsurface into the atmosphere, probably at about 10 times faster. So at least an order of magnitude faster than has ever happened before in geological time, including the mega eruptions which caused mass extinctions.

Mark Lynas: So how well the Earth is able to buffer this very rapid change in atmospheric chemistry and the resulting energy budget, we don’t even know from looking at the geological past because this is an experiment which has never happened before.

Robert Wiblin: Okay. So it sounds like you think that the two most probable indirect channels by which we could get civilizational collapse is through famine firstly, and then through war or conflict being prompted by climate change. Is that right?

Mark Lynas: Yeah. So I suppose water, fresh water supplies is another big concern. And that’s not just sitting around and waiting for it to rain. But the reality is that most of the world’s crop production is rainfed as opposed to being irrigated. And with irrigation of course, you have to have a natural fresh water supply, where you can extract water from ground reservoirs or from rivers. There’s always adaptive potential there too though. If you’ve got enough energy, you can desalinate sea water and produce large quantities of fresh water that way. But again, it’s anyone’s guess how far that’s realistically possible, in terms of replacing the fresh water needs of continents which have billions of people.

Arden Koehler: So, the freshwater, that’s mainly one of the mechanisms by which we might get famine or is there another independent way in which it might lead to civilizational collapse?

Mark Lynas: Oh well, I mean, clearly if there was no fresh water, a city can’t survive without fresh water for more than a few days. It’s a bit like electricity in that sense. I mean you switch off certain things, that’s worse even than food. Food, maybe you can buy enough stock for a couple of weeks. But water, much less time, obviously. So yeah, that kind of day zero I think they were talking about in Cape Town when their reservoir finally dried up. But I think they’ll be better prepared for the next time. So they’re obviously investing already in desalination and in more reservoir capacity. So there’s not some day of the dead, where we all run out of water at the same time. It’s something which will happen in different times at different places if it isn’t predicted in advance and if adaptive measures aren’t taken.

Arden Koehler: But you think of that as one of the more worrying scenarios when it comes to indirect ways that climate change could bring about the collapse of civilization?

Mark Lynas: Well, I think the most unpredictable way is through conflict and refugee flows, and things like that. I mean, there’s been attempts for example, to link the Syrian conflict to climate impacts. And there’s no doubt that the resilience of societies were undermined in that region due to drought, really serious drought for the previous 10, 15 years beforehand, which meant that a lot of people left the land and were forced to live on the edge of cities as refugees, and the regime wasn’t supporting people. And those kinds of conditions lead to popular protests, which then led eventually to civil war. But that’s contingent on a lot of other factors like the responsible government, which was obviously to try and barrel bomb and gas people, and led to a really horrific conflict with a very large number of refugees.

Mark Lynas: It’s been different in different countries where, if the government falls quickly, then you can get a different government come in and maybe even address some of those concerns. So it’s contingent on so many different unpredictable factors that you just don’t know. But obviously, if you have a large enough conflict with a high enough rate of mass death from maybe nuclear weapons exchanges or something like that, and you can get large scale societal breakdown as a result of that too.

Famine [00:58:53]

Robert Wiblin: Okay. So let’s maybe talk about the famine channel first. I’m worried about that, but I think a bit less worried than you. I guess there’s two ways or two things that we could maybe look at. One is: what is the probability that we have a really big food shortfall? And then, what’s the probability that that leads to some kind of cascading civilizational collapse? Let’s maybe do the second one first. So imagine that we do have a whole bunch of breadbasket areas that all have a drought simultaneously. And so food output globally goes down a bunch. Let’s say we only have 70% or 80% as much food as we have in a normal year. What’s the path by which that leads not only to a lot of people dying of hunger, but it also leads to civilization as a whole falling apart?

Mark Lynas: It’s reflected in prices. So I mean, obviously, the price mechanism is the rationing mechanism that we have to decide who gets to eat and who doesn’t in pretty much every society. And there was some forewarning of this in the 2008 food price spikes, which were more related to the oil price at that time actually than the scarcity of food. But I think the same thing would happen. And even then, the food producing countries ceased to export. And so they put on export bans, which then affects the commodities trade. That means that importing countries experience both rapidly increasing prices and their result is food insecurity. So if the price is double, triple, I mean, you’d get more than a 30% reduction, by the way, if you lost that much harvest. You’d lose all of your world’s fair trade. So food importing countries could potentially starve very quickly. And people aren’t just going to sit there and gradually get hungrier and hungrier. They’re going to move. They’re going to move in their millions to try and find whatever foods are available anywhere. And those kinds of dynamic effects, I think, there, both very difficult to predict, but–

Robert Wiblin: Don’t look good.

Mark Lynas: No, they don’t: exactly. No, they don’t look good. They’re not going to have an outcome which means that everything’s hunky dory.

Arden Koehler: So maybe people moving around in order to find places where they can eat might lead to refugees and that would possibly lead to conflict. Is that the idea? And then that would lead to collapse?

Mark Lynas: I guess. I mean, it’s again very difficult to predict the response of countries which do have food sufficiency. Are they going to be prepared to share or are they going to put up borders and build walls? The evidence from the Syrian refugee crisis suggests that the response would be to close borders and build walls and allow people to drown in the Mediterranean in their thousands, as Europe has done. And look at the political ramifications of that. You then saw a rise in populist movements and almost fascist type political parties, which are now in power and stuff, in European countries, and take us back to a time which is scarier than any since the 1930s, I would say. And this is Syria. This is one country. Imagine this happening across the majority of the world’s countries. Then those countries which do produce enough for themselves, they’re really going to have a tough time. So yeah, we can take glimpses of the future perhaps, from some of the really awful things that have happened in previous years. But there’s a multisystemic nature. It doesn’t really give you a sense of the magnitude of the result, I don’t think.

Robert Wiblin: So when I envisage a situation where there’s a huge food shortfall like that, firstly, I think we’ll probably have some heads up that this is coming ahead of time. You start to notice the warning signs earlier, like food prices going up, and food futures going up. And then I imagine that people would start… Because it’ll be a global emergency much worse than the coronavirus, say. You just start seeing everyone starts paying attention to how the hell can we get more calories produced? And fortunately, unlike 500 years ago, we are in the fortunate situation where most people today aren’t already producing food, and most capital today isn’t already allocated towards producing more food. So there’s potentially a bunch of elasticity there where, if food prices go up tenfold, that a lot more people can go out and try to grow food one way or another. And a lot more capital can be reallocated towards agriculture in order to try to ameliorate the effects.

Robert Wiblin: And you can also imagine, just as everyone in March was trying to figure out how the hell do we solve this COVID problem, everyone’s going to be thinking “How can I store food? How can I avoid consuming food? How can we avoid wasting food? Because every calorie looks precious”. And maybe that sense of our adaptability, or our ability to set our mind to something when there’s a huge disaster and just throw everything at it, perhaps makes me more optimistic that we’ll be able to muddle through, perhaps more than you’re envisaging. Do you have a reaction to that?

Mark Lynas: My reaction is: imagine if Donald Trump is in charge of the response. It’s all very well to have optimistic notions of technological progress and adaptive capacity and things. And yeah, if smart people were running the show, that would no doubt be the most likely outcome. But smart people don’t run the show most of the time, in most places, and people are amenable to hate and fear, and denial and conspiracies, and all of those kinds of things as you’ve seen, even in the very short term challenges of COVID.

Robert Wiblin: Yeah, it is interesting. I’m not sure whether to update positively or negatively on society’s resilience watching COVID. There’s some places that have handled it really admirably well, and I’ve been impressed by how good their governments are. And then other places where it’s just been remarkably incompetent. Something that’s really struck me is how disruptive it’s been to have a virus that has an under 1% fatality rate, which you think, in the scheme of pandemics really isn’t that serious and yet it threw everything into disarray pretty quickly which has maybe made me more worried about these flow through effects being something like “Well, if 10% of people are starving, how much disruption does that create to everything?” And I guess the fear of conflict; how much does that make it hard to get anything done?

Mark Lynas: And it wouldn’t just be a global average of 10%. You have a global average of 1% for COVID. It would be, I don’t know, 50%, 90% in certain places. And I think that would be a psychological shock to us as much as anything. Even if you’re in a country which is likely to survive, just seeing that extent of famine would be, as you say… We haven’t seen anything like that since the medieval times but yes, societies tolerated the Black Death, the loss of half of the population across much of Western Europe at certain times, and there were famines, which probably had death tolls of similar magnitude in those times as well, and what do people do? They worshiped, they castigated themselves, they fought wars, but they survived. So that isn’t necessarily the herald of extinction but remember, these processes are getting worse. Unless we’ve stopped emissions by that time, because the economy just can’t… Which I think actually, is quite likely the more people talk about this. How are you going to carry on burning huge amounts of coal, or any kind of fossil fuel, if society is so challenged by a mass famine, for example?

Arden Koehler: That brings me to a question that I wanted to ask you because it came up in your book. So when I have thought about whether climate change might cause extinction, and maybe we can come back to this, but I thought, okay. Well, what if it warms 10 degrees or 12 degrees or 15 degrees, then maybe we see people dying just of heat stress. But then I thought, well, but how could we possibly continue burning fossil fuels over the hundreds of years required to warm the planet that much? Assuming that there would be these huge effects before any of that happened. For instance, these famines, and how could people continue to want to burn fossil fuels throughout that entire time? And so that was making me feel more optimistic that we wouldn’t get to those extraordinary temperature rises.

Mark Lynas: So your source of optimism there is that if warming is especially extreme, it will trigger enough societal collapse so there will be lower emissions and therefore you won’t get a runaway feedback effect.

Arden Koehler: I agree it’s an attenuated sense of optimism. So yeah, something I was imagining, is it possible to get to these extraordinary levels, and I thought, how could we keep burning until we get there? So yes, in some sense. Not necessarily through societal collapse, it could also be through people being like, “Oh my God, this is having such huge effects. This is becoming so politically urgent that we have to stop burning fossil fuels”. So that was the thought.

Mark Lynas: Great, well, I’ll take comfort from that.

Arden Koehler: Okay. Well, unfortunately… Yeah. So I was reading your book and you mentioned that one issue with talking about adaptability is that it’s going to be much harder to adapt without burning fossil fuels if we haven’t already transitioned into a carbon-free economy. So fossil fuels are the source of our ability to do so much. So maybe people will feel like, “Okay, well we really need to just, for the next five years, we really need to do this huge project in order to adapt which is going to require us to use a lot of energy, which is going to require us to burn a lot of carbon”, which might make it so that people are more likely than I had initially intuitively thought to continue releasing carbon into the atmosphere, even as things get really, really bad.

Mark Lynas: Well that’s the Dubai scenario, where you have an oil dependent… Well, a petrostate under a huge air conditioned dome in an intolerably hot environment which is entirely dependent on artificial water, I mean, artificial energy generally, and food from elsewhere. So yes, it’s certainly possible that whole cities can exist in an ambient environment which is intolerably hot, but you can’t do that over an entire subcontinent. You can’t build that dome. I mean, you can see this process already happening, just with air conditioning. So air conditioning demand is one of the biggest drivers of increased energy use and increased coal burning in India, for example, and other places too. So maybe that’s a kind of feedback, a smaller scale version of the feedback you’re talking about.

Arden Koehler: Yeah. It’s interesting. It’d be like a human feedback loop or something.

Robert Wiblin: I think one part of what Arden is gesturing at is that, if in 50 years time, people see that the world is on fire or things are going horribly because of climate change, some people have the intuition that, “Oh, won’t that cause us to stop burning fossil fuels because we’ll have seen by that point how reckless it is to do so?” But I think that underestimates human stupidity. I’m not very calmed down by that because the international public good problem will still be there. The fact that the incremental emissions that you do at that point in order to deal with that situation, that’s going to cause problems more in the future than it does right away. I could totally imagine a situation where the world is falling apart and people maybe even want to burn fossil fuels even more because they feel desperate to find some way to cope with the situation and that just makes it worse.

Arden Koehler: Or they’re like, it’s already so bad, we might… Or there’s some sort of defeatism that could happen.

Robert Wiblin: “What the hell”.

Mark Lynas: Well then also it’s true now that the higher your level of development, and the higher your level of emissions and oil consumption, the more resilient you are likely to be to climate impacts. When the hurricane hits, if you’ve got a society which has advanced infrastructure and is therefore probably very dependent on carbon fuels, then you’re going to have a much lower death rate. So yes, there’s already a conundrum for countries like Bangladesh. That ironically enough, your best way to resist climate damage is to burn as much fossil fuels as possible and to become as developed as possible, as rapidly as possible. I don’t see why that dynamic would ever necessarily disappear unless clean energy becomes cheaper than fossil energy.

Robert Wiblin: Let’s return to this famine issue. So it sounded like you thought that, in some of these three or four degree warming scenarios, we could end up with food production halved or more in a given year, which is perhaps more than a bigger impact than I expected. Yeah. Maybe try to convince me of that. That’s how big the effect could be.

Mark Lynas: Well, you just need to look at the scale of the issue. I mean, in terms of food production, it’s only a few hundred millions of tons which make up the food trade, which is only a few percentage points really of the overall production. So you don’t have to lose very much to eliminate all of the traded commodities of rice and corn and wheat and things that now constitute the majority of the calories for importing countries. So you’ve got this … It’s Ricardo, isn’t it? Going back to classical economics, you’ve got this specialization where countries which can produce food, do, and then trade it for other things which are produced in countries which have a better capacity to do other things.

Mark Lynas: So the other thing you’ve got to think about is, to what extent does that drive us into the Ricardian production model, where everyone closes their borders. You only think about your own population, you ignore famines abroad. Clearly, when politically, leaders are responsible to their own populations, that’s your main motivator. You don’t care whether people are dying in faraway countries. And, like I say, that did begin to happen in 2008. The first response was to close borders and to stop exports. Both in order to protect the price, and to protect supply at home. Because if you’re exposed to international markets, then you get increased prices, even in a domestic situation where you produce enough food yourself, of course. So that dynamic between globalization and a return of protectionism, I think, would be a huge driver of what actually happened in terms of food security globally.

Would climate change really cause war / conflict? [01:12:05]

Robert Wiblin: All right, let’s maybe talk about the conflict route. And this is one where I think I just feel more intuitively skeptical about climate change causing wars than many people seem to be. It’s something that a lot of people say, and then when I think about it concretely, I’m like, “Why would they go to war?” So even if you have a famine, or even if you have refugees coming across, I could see that causing a lot of political chaos. But perhaps this is bringing out the rational agent economist training in me, where I’m just like, “But going to war wouldn’t help to solve those problems”. And indeed, when you have a recession, when you have a lot of other problems to deal with, like the pandemic… We have this pandemic, people aren’t really talking about going to war because it wouldn’t help to solve the pandemic, and it’s very costly while you’re dealing with other emergencies. So maybe try to pitch me on the idea that climate change has a decent probability of causing international conflict that could really get out of control.

Mark Lynas: Well it doesn’t have to be international conflict. I mean, most conflicts are within national borders, obviously. So I think what tends to happen, and there has been some published work on this, is that resource scarcity intensifies into intergroup conflict. So you get more of an ethnic phenomenon, really, where certain groups try to monopolize scarce resources within a nation and that leads obviously to conflict, and potentially to a breakdown conflict scenario as a result. And those wars can then spill over. I mean, look at Syria. It’s not just a civil war, it’s pretty much a great power conflict, or certainly was before the US exited, where you’ve got different powers jostling for dominance within that scenario. You’ve got Iran, you’ve got Israel, you’ve got the US, you’ve got Russia. It’s not just about whether the Syrians have to keep their dictator.

Arden Koehler: I think some people might think that, in order to get societal collapse, and maybe it’s possible we’re talking about different things here. But if societal collapse means something like the industrial economy is reduced by a huge percentage, and the political systems around the world don’t work anymore. And thinking about something that’s very, very widespread and very, very dramatic, such that we might think it could set us up to stagnate for a very long period of time as a species, I can imagine some people thinking that in order to get something like that from conflict, you would need to have a hot war between large powers in order to get enough destruction to make something like that happen. Does that seem plausible?

Mark Lynas: Yeah, but I can’t imagine what the scenario is… You’re into science fiction, really. I think all you can say is that when you’ve got resource scarcity, you’ve got a higher potential for conflict, given the competition that comes as a result of that. Whether that’s intergroup within nations or potentially between nations, if you’ve got conflict … I mean, people have been expecting water wars for ages already, and you’ve got conflicts between say, India and Pakistan. Or currently, I think, between Egypt and Ethiopia over the Nile. I think Ethiopia’s just been building a new dam, so that’s obviously going to take some of the water from the Nile and affect the amount of fresh water that comes downstream to Egypt. But are they going to fight a war over it? Is Egypt going to bomb the Ethiopian dam? I mean, it probably wouldn’t be good for them if they did.

Mark Lynas: So actually, a lot of the time, it’s better for both sides for these kinds of conflicts to be resolved through negotiation than through warfare. And that’s particularly the case when you have nuclear armed states. I mean, I think there’s a strong argument that you’ve had a much lower rate of interstate warfare as a result of nuclear weapons than you had beforehand when the stakes for going to war were much, much lower. And those things aren’t going to change. Nuclear weapons aren’t going to disappear. So I struggle to imagine the scenario where climate change leads to World War Three, let’s say. But in a more unstable, resource-constrained world, I think you could certainly argue that it’s more likely to go in that direction than less.

Robert Wiblin: So moving on from the conflict scenario, which it sounds like you think it’s a little bit challenging to make the case that it’s directly going to cause an international or a global power conflict. I think other things that inform my general hopefulness about this, I’m not optimistic about everything, but I feel that there’s some degree of positivity about this is that, as you were saying earlier, despite the fact that there’s more natural disasters now, the number of deaths in natural disasters is down 90%. Even though the population has increased several fold over the last century, which really seems to indicate that, on balance, our ability to adapt and build things and invent things is winning out in that case. I mean, natural disasters are only responsible for about 0.1% of deaths over the past decade. So even if it increased tenfold or a hundredfold, that does seem survivable. And then people talk about ocean rising being very problematic. Then you look at the Netherlands, and you’re like, “Well, already a third of this country is below sea level, sometimes often several meters below sea level, and the Netherlands seems to be doing fine. They just use infrastructure to get around the problem”.

Robert Wiblin: And then I think, “Well, why couldn’t New York do that?” Why couldn’t other, at least rich cities, do that? And then I’m hopeful that, in 30 years’ time, 60 years’ time, more and more places will have industrialized, will have developed a bit like China, South Korea, like Vietnam is doing now, which will give them more ability to build the dams that will protect them against sea level rise. And to put more effort into high-tech agriculture so that they can reduce the risk of a famine. I guess this thing just goes to a deep worldview about how optimistic you are about human adaptiveness, and it sounds like, on balance, you really are fairly optimistic about human adaptiveness, but yeah. Do you have any take on that?

Mark Lynas: I’ve become less concerned about sea level rise as a serious stressor on societies. Obviously that doesn’t go for small island states. If you’re a coral atoll, you can’t build a wall because the water’s going to come up through the middle and ultimately, the waves are going to wash over your entire land. But if you’re doing numbers, that’s a relatively small proportion of the world’s population. Well under 1%, I would have thought, probably much less. It’s a few millions of people, really. Big deltas like, I mean, Bangladesh is a delta, which actually, the Netherlands is too… You can protect, and in fact, most of Bangladesh, if you ever go there, it’s protected by a whole network of dykes and walls and things. So they have their own polder system without which, you wouldn’t be able to produce nearly as much food or keep the population as they currently are in coastal regions in Bangladesh.

Mark Lynas: So all these societies are already adapted to flooding and sea level rise. Flooding, by the way, is an issue, as well. Because if you’ve got a lot of water coming down in the monsoon season at the same time as you’ve got water coming up from, let’s say you’ve got a coincidental cyclone and a higher sea level as well, it does become difficult. But I mean, there was, what was it, now: 170,000, 200,000 people killed by cyclones in the 1970s in Bangladesh. That never happens now. You’re very unlucky if you get a death toll over 100 for a cyclone of the same kind of intensity. So it’s down by much more than 90%. It’s orders of magnitude, in terms of how likely people are to be able to survive, even increasing the extreme natural disasters. So absolutely, that’s good news. And in terms of the ocean rise, it’s just very slow. Nobody has to drown when sea levels are rising by even if it’s a centimetre a year. It takes… you’re not just going to stand there. So what are the scenarios?

Mark Lynas: I mean, I talk a bit in the book that there’s a risk of catastrophic failure, the more you pen your cities behind sea walls, and the seas are rising around the outside all the time. That you get a New Orleans type failure of the levies, then you get a very rapid flooding of large areas. And that absolutely can kill people. But these things actually are quite predictable. And even the most extreme scenarios for sea level rise wouldn’t give you more than two and a half meters by 2100. So yes, that’s tolerable for most of the world’s coastlines probably, with a substantial amount of money spent on personal engineering, or moving people away.

Mark Lynas: I mean, in the UK, we seem to abandon large coastal areas and let them return to the sea, or return to coastal salt marsh, and things like that. Which would be good for wildlife anyway. So we can’t, and we shouldn’t aim to protect every single part of the land from the rising seas. You also get a problem with bay line intrusion into aquifers. And so, saltwater will find its way into the land, even underground, if you like, which you can’t obviously protect the source either. But there’s different dimensions to this issue too. And so, you often hear that the Greenland ice sheet will collapse. I actually think the Greenland ice sheet will collapse already, even at the level of warming right now. And I don’t think it can be sustained. You’ve already got melting right to the summit of Greenland.

Mark Lynas: So you’re now removing ice across the entire Greenland ice sheet, actually, every summer. And it won’t be long before that happens all the time, as opposed to it being a fairly rare event now. But when you’ve got an ice sheet which is three and a half kilometers thick, how long does it take to actually melt it? I mean, it takes centuries. You can’t make it happen in the timescale of years or decades, just because of the physics of that. And Antarctica, as well. You can speed things up a bit if you collapse on marine-terminating glaciers like in Antarctica. You’ve got the Thwaites and the Pine Island Glacier. Less so in Greenland. But the major ice sheet collapse scenarios take a very long time to play out. And so sea level rise, as a result, is also very slow in a human timescale. It’s very rapid in a geological time scale, but I think that’s something we absolutely should be able to adapt to, even if we have to move cities and land, then that’s okay. I mean, look at the difference between Hong Kong in 1950, where it was basically a fishing village and/or Shanghai, even more so, and where they are today. So huge amounts of infrastructure, entire cities get built in the space of a few decades. They built new cities further inland. It’s certainly imaginable.

Robert Wiblin: Okay. So I guess to wrap up this section, it sounds like we agree that the most likely way for climate change to cause civilizational collapse is perhaps if it’s quite rapid. Or you get some really rapid increase in the climate effects so that we don’t really have time to adapt to it. Probably going through food shortages is most likely, maybe water shortages second most likely. And then it probably also requires that we react pretty stupidly or we react in a competitive zero-sum way and start fighting one another. And just trying to grab the resources rather than try to instead put our mind towards technology that can solve the problem. And if you get those three things, then things start looking hairy, and we’re not quite sure whether humanity is going to make it out in a decent state. Does that sound right?

Mark Lynas: That’s a good summary, particularly if you’ve got positive feedbacks which are happening at the same time. We’re all aware of it. The sunsets are particularly lurid because you’ve got most of the Amazon is now in smoke circulating in the lower stratosphere. And you’ve got very large scale melt in the Arctic permafrost, then methane levels in the atmosphere is shooting up. And there’s a sense really that the whole issue is beginning to slip beyond humanity’s control. And I think that would have a huge psychological and political impact. You know what I mean? It would affect how we respond to it as our understanding of how far the situation is now going beyond… It’s actually going beyond our… You get less techno-optimist if you think, “Shit, we’ve pushed the lever so far that we’re now tumbling over the cliff”.

Robert Wiblin: No, it’s like, yeah, well, I hope maybe we can do a full episode, just maybe with a social scientist or someone who’s thought about societal collapse, and when do things break down, and when the people react constructively in future. It seems like we could spend hours on all the different sub-questions here.

Mark Lynas: The thing is, people don’t tend to have rational conversations about this. So in fact, you get the collapsitarians and the doomsters who think that cycle extinction is not just inevitable, but in the near term inevitable, and in a little way desirable. You often get that sense from this kind of post-Christian-millenarianism, where the environmental challenges are the new ‘Hand of God’ sort of thing.

Arden Koehler: I see. It’s our punishment?

Mark Lynas: Yeah, exactly. It’s a punishment for our decadent over-consumptive ways. There’s so much of that in the discourse that you get amongst the more climate alarmist section. So that’s always based on cherry picking the science, but it’s got through with a kind of psychological angst. And then on the other side, you get the techno-optimists, who believe that we can solve our way out of any problem by inventing new things. And it’ll all solve itself in some giant Kuznets curve. I feel like I’m in quite a minority in trying to engage with both sides of that debate and try and have a… I wouldn’t say rational because that’s blowing one’s own trumpet, but to try and have a better approach to how you’d actually discuss these issues.

Arden Koehler: Aiming toward a rational discussion.

Robert Wiblin: I do find it really baffling that there isn’t more proper, thorough analysis of this, like academic analysis. I remember years ago, I realized that I’d just heard so many times this idea that climate change would cause serious conflict. And I was like, I don’t really see the story here that’s super compelling to me. And then I started looking around; “What’s the best analysis written on this question where they break down all the different potential paths to conflict and then think about how likely they are”. There’s nothing. People just say this, and then it’s just left, and no one really thinks that it’s their responsibility to figure out whether it’s actually really true. So, I mean, I think there’s a lot of potential… Listeners, if you’d like to go away and analyze this question, I think there’s surprisingly fertile ground here to say something new.

Arden Koehler: To be fair, people have, I mean, there’s been some research on climate and conflict in very small scale conflict. And so there isn’t nothing, but it’s true that it’s very underdeveloped.

Mark Lynas: Yeah, I completely agree. And I guess a lot of the time, it’s one thing to try and model the response of the Earth’s system to increased greenhouse gas concentrations, but I don’t know how you’d ever predictably model the response of human societies to… Obviously, all of these systems are dynamic and nonlinear, but like I said earlier, we don’t even understand how the economy works. We can’t take a rational approach even to economics, much as many economists claim to try. So how would it then feed through into political responses and cultural responses? It does become almost impossible to say anything with any kind of predictive value, perhaps.

Robert Wiblin: Yeah, well, one other thing I might just say to wrap up is, even though I think I feel a bit more optimistic maybe than you do, or I would place lower probabilities on civilizational collapse than you do, maybe because I think, “Well, if we responded rationally, things would be able to go fine”. I think–

Arden Koehler: Well, not fine, of course.

Robert Wiblin: Right. Yeah, exactly. Not extinction level, but I think we can see from history that people don’t always respond rationally, and that things can be interconnected and very chaotic and really spin out of control when it doesn’t really seem like they had to spin out of control, but they did. There was kind of an escalation of how bad things were, so I’m more optimistic than you, but I’m definitely not that chill about it. I really worry, and I would really prefer that we didn’t have to find out whether we were resilient to these stresses.

Mark Lynas: Yeah, absolutely.

Nuclear 2.0 [01:27:11]

Robert Wiblin: Okay. Let’s push on towards talking about specific ways of addressing climate change. The first step, let’s cover one of your preferred solutions to climate change, which, as you’ve mentioned, is nuclear power. In 2014, you published ‘Nuclear 2.0: Why a Green Future Needs Nuclear Power’, which makes the case for a big scale up of nuclear power, more than doubling the number of plants over 15 years. I really enjoyed this book because it covers kind of all of the key issues that you wanted to raise very clearly and very quickly. You could finish the book in one session, which is something I wish was the case of more books. You also just throw in a lot of numbers to really explain why you hold the views that you do. So yeah, in brief, for the audience, can you explain what makes you so enthusiastic about nuclear energy?

Mark Lynas: It comes down to physics, actually, so you’ll like that. It’s really to do with the energy density of nuclear as a fuel, and that’s the key issue if you’re concerned about scalability. You’ve got to find an energy source which provides carbon free power to a 10 billion strong population, at the same time as people have probably doubled their energy demand, or tripled it, even more, given that most of the world still underconsumes in relation to us in richer countries.

Mark Lynas: How do you do that without destroying the rest of the world’s ecology, as there’s not really any other way of doing it than nuclear? Fossil fuels are already very energy dense, particularly given that they come from underground. Hydrocarbons are an incredibly adaptable and versatile way of powering long distance transport, for example. Coal is a brilliant way to run industry and to generate power, apart from a few million dead every year from particulate pollution, and small things like that. But uranium is something like a million times more energy dense than hydrocarbons, so you can power whole countries with a few tons of the stuff, really, and the materials flows and the waste flows are simply trivial in comparison, and raise no significant environmental challenges or indeed engineering challenges. It’s just doable, and it isn’t doable with any other approach that you can imagine.

Mark Lynas: Renewables are not energy dense, so you have to cover immense areas of land to capture enough solar power through photovoltaic technology to even go a small distance towards addressing our current energy consumption with solar. And wind likewise. The power density per unit of land area is very low for renewables and very high for nuclear, and the difference is orders of magnitude.

Arden Koehler: So if that’s the case for nuclear or for scaling up nuclear, what do you think is the best argument against scaling up nuclear power? What’s the most likely way you could be wrong about this?

Mark Lynas: The only argument against is a political one, that people won’t accept it, or people won’t want it, so nothing to do with engineering. I don’t think there are any engineering or physics challenges that can’t be fairly easily addressed, and that includes the cost. Yeah, nuclear is very expensive at the moment, but that’s because it’s trying to satisfy safety concerns, which are taken vastly more seriously than any other type of infrastructure projects, and therefore require multiple redundant safety approaches, which cost a huge amount. You’ve got to build, I think, the EPR reactor at Hinkley… They talk about it’s like building a cathedral inside a cathedral. That’s the kind of engineering which we’re left with to try to reassure the public that this isn’t an existential threat. What’s that? That’s not engineering. It’s a psychological challenge. It’s a political challenge. The only way that I think it’s wrong is if people won’t accept it, and we waste time trying to do it instead of simply paving over whole countries with solar panels, if that’s the only way that’s mostly acceptable.

Arden Koehler: Just to clarify quickly on the cost point, are you saying you think we should have less safety redundancy in nuclear power, or more in the others or something, when you talk about this cost being inflated for nuclear, and that being artificial?

Mark Lynas: Well, it is one of the major cost drivers. No one in the nuclear industry would ever say “Let’s save costs by reducing our safety components”. But those of us who are not in the industry can say, “Well, look. Why is it that nuclear has to fulfill this safety concern vastly more than anything else?” Cars aren’t that safe. Nothing’s that safe.

Robert Wiblin: Coal power is not that safe at all. It’s the reverse.

Mark Lynas: Well, no, not only coal, but even wind and solar aren’t that safe in terms of numbers of fatality per gigawatt hour, or however you want to quantify it. People fall off roofs putting solar panels on, and wind turbines fall apart and whatever, so nothing’s completely safe. Even in the worst case scenario, nuclear accidents, at least with the type of technologies we’re using, I wouldn’t use Chernobyl because that’s not the kind of reactor that we’ve got built anywhere else. But say Fukushima in Japan, which was about the worst, like a triple meltdown in the context of a much wider natural disaster, that’s about as bad as it can get. How many people died from radiation? Zero. That’s not even on the same scale as Piper Alpha, where the oil rig blew up and killed 150 people, or any mid-range industrial accident.

Mark Lynas: But why is it that nuclear has to shoulder these immense costs? Because of this perception that it’s somehow an existential risk. You see this all the time. People say, “Well, imagine if”… A lot of Greens say this, “Imagine if one nuclear power plant somehow contaminated another one, you get this cascading fail”. They actually imagine this is a pathway to human extinction. I’ve never heard anything so stupid, but people’s psychology is so mixed up on this. It’s very difficult to draw a line between what’s psychology and what’s engineering in terms of how you deal with the safety issue, but just to finish up, yes, let’s not have to have a compromise between safety and cost. Let’s move to different kinds of designs and reactors which are passively safe, where you can walk away from them and they will shut themselves down, and there won’t be any release of radioactivity in almost any imaginable scenario. Those designs exist, and they should be available and cheaper than what we are using at the moment, fortunately.

How technology has improved since 2014 [01:33:03]

Robert Wiblin: In 2014, your main concern was also cost, but there were a bunch of other things you’d like to see improved about nuclear power, like this kind of modular designs, and using different fuels. How has the technology come along in the last six years in terms of cost and safety, and I guess, practicality?

Mark Lynas: Well, if you’re looking at light-water reactors, Hinkley’s thing is at least being built on a schedule at the moment. It looks very expensive because it’s a huge capital cost over a long build, so you don’t start getting payback for quite a long time. The cost of capitalism is really the main issue with infrastructure projects of that nature, but it’s the same for building a bridge or the Scottish Parliament, or pretty much anything, actually. We’re not good at doing that in Western countries anymore. It always looks eye-wateringly expensive to do something big. Look at HS2, the high speed rail. It’s in the hundreds of billions, I think now, in terms of what the projected cost of that is. The Victorians just went ahead and built these things.

Mark Lynas: Cost is a moving target anyway, but some of the small modular reactors and the more advanced designs have come a long way. ThorCon, for example, which is one of the molten salts thorium designs, has got most of the way towards working with the Indonesian government on a prototype and potential build out there, which I think is really interesting. Their design is completely passively safe. They’re looking at a faster route, which I think is about $1,500 per kilowatt in terms of the CapEx, so it’s about a fifth of the cost of any EPR. That’s what I mean. Obviously, these are quoted prices, and you don’t know until you actually do the thing. Even then, the prototypes are the first of a kind cost, which is obviously a lot higher than the nth of a kind cost when you’re doing lots and lots of these things. If our only roadblock that’s in the way of stopping climate change is making nuclear cheaper, I’m sure we can do it, just as what’s happened with solar. Solar is now way cheaper than it was, again, orders of magnitude, than it was a couple decades ago, and nuclear can do the same.

Robert Wiblin: Yeah. So speaking of which, costs of solar and batteries have just come down a lot since even 2014 when you wrote that book, and maybe they’ve been even been coming down faster than people predicted then. Has that made you reconsider at all whether nuclear is really necessary, and whether we might be able to do it just with renewables, if we had to?

Mark Lynas: No, because the power density of renewables doesn’t change. That’s a physical reality, which is related to the amount of sunshine or kinetic energy that you can harvest from a particular unit of land area. You can get slightly more efficient solar panels, but it’s a few percentage points at most. You’re never going to be able to get away from the fundamental issue of needing to pave over country sized areas of land to generate enough renewable power to fuel modern industrial civilizations. That’s a fundamental physical reality which is never going to change. It might be slightly cheaper to do that because solar panels have come down in cost, but it doesn’t change the fundamentals. No, I’m not really in a different place from where I was when I wrote Nuclear 2.0.

Robert Wiblin: Couldn’t we just stick all the solar panels in a desert somewhere where practically no one lives, and then put up high voltage lines to transmit them to cities? Can we get much mileage from that?

Mark Lynas: Yeah, but even deserts are ecosystems, and they’re wild areas. When, I think it’s Ivanpah, that big solar plant in California in the Mojave Desert was being built, they were bulldozing cacti. They were pulling desert tortoises out of their burrows and sticking them in the back of pickups to be translocated elsewhere where they all died. There’s no such thing as an ecological free lunch, particularly when you’re talking about harvesting power over vast areas of the planet’s surface, which are currently still wild. That’s the opposite of a rewilding agenda, which is what I’m most enthusiastic about, where we need to let go of human impact over as much of the world’s land as we can do while still producing food. Why you’d want to bring energy into a land-use conflict when you’ve already got food in a land-use conflict, I can’t imagine.

Robert Wiblin: My overall view is that I’m super sympathetic to nuclear power and what you’re saying, and I’d be really happy to see more plants getting built. It’s crazy to see plants getting shut down early on, and then replaced with coal power in some places. I guess a lot of the common objections that people have around safety and other things are pretty weak, but all that said, I’m not sure whether promoting nuclear power is a top low-hanging fruit way to reduce climate change, I guess for three reasons. Firstly, there’s this thing that solar is decreasing so much, and maybe I’m more optimistic than you that we can find some way to stick the solar panels someplace that people will accept. At least maybe that’s easier than getting nuclear built. I guess if solar cost decreases continue, then maybe it will just end up being cheaper as well?

Robert Wiblin: Then there’s also, I guess I should say Europe and the US just seem to have forgotten how to build things now. It’s hard to get a bridge built, let alone a nuclear power plant. I’d love that to change, but I guess I am not holding my breath, so maybe nuclear power has more of a future in Asia or something, rather than Europe or the United States. I guess also, like you said, people just hate nuclear energy so much to such an irrational degree, that the problems just seem really severe. While I’d love that to change, I guess I’m not sure whether making all of these sensible arguments about why it’s actually a good option is going to be enough to get rid of people’s instinctive fear. Do you have any take on that?

Mark Lynas: There’s a lot there.

Robert Wiblin: Yeah, sorry.

Mark Lynas: It comes down to are you serious about having a plan to tackle climate change, which actually adds up and is physically possible? I’m putting that question to Greenpeace, to Extinction Rebellion, to you, to the Conservative Party, whatever. If it’s a renewables only approach, then you’re not serious. It just isn’t conceivable to imagine the kind of materials for those. Yes, you can put all of the solar in hot deserts, but the transmission lines… You’ve got a transmission line, let’s say, between Algeria and Libya. Oh, Libya has just gone. Whoops. There’s energy security issues for that, just as there are with the modern-day oil industry, where we’ve got geopolitical, obviously, conflicts resulting from our dependence on Middle Eastern oil. So yes, you could probably design an outcome where you’ve got most of the Arabian peninsula covered in solar panels, but electricity to the high consuming markets is very difficult, even with high voltage DC, not to mention the security risks of that.

Mark Lynas: Perhaps a better option is for hydrogen production, so to produce synthetic liquid pills using the sort of stranded asset of hot deserts. I know people who are working on that, and I think it’s certainly conceivable that that could be a significant part of the approach. When I try and be physically realistic about the renewables issue, it’s not to say we shouldn’t do renewables. I’m currently involved in launching a campaign called ‘Nuclear for net zero’. I don’t know whether it’s going to happen or not, but we’re just conceiving it at the moment. I’m quite happy to say, “Okay, let’s have in the UK solar PV equivalent to 10 times Hinkley’s fee, so let’s build your one and a half Wales’ of solar. I don’t know quite where you’re going to put it. Actually, it’s not that much. It’s only about two Surreys, actually. Let’s just sacrifice a couple of home counties with solar, by all means, but we’ll still need even a few, well, probably 40 or 50 gigawatts of nuclear as well, and if you’ve got offshore wind, and if you’re going to produce significant amounts of hydrogen in the UK too.

Mark Lynas: So the only way you can get around that is to say, “No, no. Of course we don’t want any solar in… Sorry, we’re going to have to put it all in Algeria”, in which case you’ve somehow got to either move the electricity, or I’m not quite sure how else you’re proposing to do it. Is that more believable than a future where you basically just persuade people to be a little bit less hysterical about nuclear, and get that back into the mix as a much more scalable and hopefully more cost-effective approach? Because, by the way, even with the reduction in solar costs, it’s much more expensive to do it just with solar and wind, just because of the materials you need. Imagine all the steel and silicone and all the rare-earths and everything, all of the different metals that you need to cover over the Arabian peninsula in solar panels. It’s immense. It’s probably many times the scale at which these material flows currently exist for all of the world’s industry.

Arden Koehler: All right. Let’s move on from nuclear power to discuss other promising ways people can help to reduce climate change. What are a few other policy or technology options that you think have the greatest potential to avoid a climate disaster?

Mark Lynas: There aren’t any.

Arden Koehler: So it’s just nuclear?

Mark Lynas: Yep.

Arden Koehler: Okay.

Mark Lynas: That’s why I care. I don’t have a particular strange fetish for reactors.

Arden Koehler: Well, I guess people talk about a carbon tax or these kinds of things. Do you think any of those are especially promising?

Mark Lynas: Those are policy levers which have to drive a technological change. What’s the technology? Ultimately, you come back to the same question.

Arden Koehler: Okay.

Robert Wiblin: You don’t think it would be… Well, I suppose I would think solar R&D, even if you think it can’t go all the way, is helpful as well. Maybe battery technology can help? It just lowers the overall cost of having stable electricity from renewables. Is there anything else on the energy side that excites you?

Mark Lynas: Well, when I said we could pave over the whole of Surrey with solar, that’s assuming that you’ve dealt with intermittency, but that’s just looking at your kilowatt hours per year, and not how you keep your lights on at night. So batteries, that’s not an issue at all. There’s nothing else. Fusion? Good luck with that. Biofuels? No, that destroys more of the planetary ecosystem.

Arden Koehler: I guess another type of intervention would be negative emissions technologies, so carbon capture and storage, for instance. How optimistic are you about that for making a big difference?

Mark Lynas: You mean carbon capture and storage from burning fossil fuels? What carbon are you capturing and storing here?

Arden Koehler: I’m imagining the atmosphere, but would be curious about the others too.

Mark Lynas: Well, in air capture, your thermodynamic challenges for that are you have to put a huge lot of energy into that process. You’ve got to somehow chemically strip CO2 out of the atmosphere where its current concentration is 400 parts per million, so that’s 0.04%. I can never get the orders of magnitude right… But very diffuse. Then you’ve got to concentrate it, liquefy it, and pump it underground in big pipes in appropriate places, so the scale of that challenge, if you think about it conceptually, is like doing the opposite to what the oil and gas industry has done times two, because it’s coal as well, but decades.

Mark Lynas: And you think about the size of all of those pipes, and all of those drilling rigs, and all of the rest of it. It’s not going to happen. You’d have to put into that much more energy than was liberated in the process of drilling and burning that oil and gas to start with, obviously because of thermodynamics. It’s like trying to make a wood fire out of ash, right: you’re at the lowest state of entropy. No, it’s not going to happen. No, it’s not scalable. And no, it shouldn’t be a major part of our conversation.

Robert Wiblin: Yeah. I’m with you on that. I guess also, in the meantime, we’ve been burning coal and messing things up, and producing all the air pollution, all the other downsides of coal. It just seems terrible on multiple different grounds.

Mark Lynas: Why would you do it when you’ve still got point sources of emissions, which have really been concentrated CO2 by the millions of tar from single chimneys? In what way does it ever make sense to try and then capture it from the air? It’s 400 parts per million concentration. So you’ve got this strange parallel conversations going on. For me, it’s a kind of psychological denialism, imagining that in some kind of future we get to be inventing magic that can reverse the damage that we’re currently doing every single day.

Robert Wiblin: Yeah. Even magic can’t change the laws of thermodynamics. What about grabbing it from the chimneys of the coal plants? Is there anything to be done there?

Mark Lynas: Well, that’s the methadone option to your heroin addiction.

Arden Koehler: It sounds like an improvement.

Mark Lynas: Maybe. But you’re still an addict, and you still flop around looking gray. Obviously you can carry on burning coal, and you can put the already concentrated CO2 underground, and that’s being done in a small scale in some places. Technically that’s manageable. You get a significant energy penalty from doing it, and to be honest, the best way to keep carbon in the ground is to leave the carbon where it currently is in geological reservoirs of oil and gas, so it doesn’t make any sense to do that in my view on that, as a large scale approach. We just don’t need to. We’ve got alternatives. We don’t need to burn that coal to start with, and it’s better off being solid, black, a few hundred meters down.

Robert Wiblin: Okay. Given that, maybe we should talk more about nuclear?

Mark Lynas: Yeah. I told you. You end up with nowhere else to go, which is the process I went through in about 2005.

Why Mark changed his mind about nuclear energy [01:45:40]

Robert Wiblin: Yeah. That’s interesting. So tell us a little bit about your evolution from being anti-nuclear to pro-nuclear. How did that happen, and how difficult was it psychologically?

Mark Lynas: Well, I was never anti-nuclear in a mobilized sense in the way that I was anti-GMO, where I was doing actions and destroying crops, and things like that. I was never an anti-nuclear activist in the sense… Anything more than the fact I felt myself to be an environmentalist, and therefore I thought nuclear power was bad, because all environmentalists do. That was really the extent to which I thought about it. It’s the generation before me. The kind of high watermark of the anti-nuclear movement was in the 1970s, China syndrome type of era, Jane Fonda, that kind of stuff. I came of age really as an environmentalist in the late, well, the early ’90s, really. That had happened, but it had become, for want of a better way of putting it, part of the DNA of environmentalism was the anti-nuclear belief. I just grew up with it, and never thought to question it.

Arden Koehler: Until you did, though, I suppose, right? What was that transition like?

Mark Lynas: It was very difficult. Yeah, I was at an energy conference, I think, where someone from the nuclear industry just said about, I think it was 15% of the UK’s power at that point… I didn’t even know. It actually hadn’t really occurred to me the extent to which we were already dependent on nuclear for, well, at that point, the majority of our carbon-free power. The first stage I was like, “Okay, you don’t want to switch it off, like they’re doing in Germany”. You switch off the nuclear, then you go the opposite direction from where you need to be to reduce emissions. Once you believe in the climate emergency, you just have to rethink opposition to nuclear. Not doing so is, well, completely irrational.

Robert Wiblin: Have you had much success persuading people? Are there any kind of green shoots of people reassessing this?

Mark Lynas: You would be surprised as to how many people deep down–

Robert Wiblin: Think it’s fine.

Mark Lynas: Yeah, actually understand. It’s a bit like most people are still in the closet. This is why I’m focused now on helping build a movement, because we need to be out and proud. We need to say this is what we think, these are the reasons why we think it, and please join us rather than… I know people in Greenpeace, Friends of the Earth, and all of these mainstream groups who know perfectly well that you’ve got to have nuclear as a major part of the mix to solve climate change, but they would be sacked if they said so, so they just keep a lid on it. I don’t think having to deny evidence is the right place for environmentalism to be, so that irritates me as well as it being in the way of solving climate change, which is the main point of this whole exercise.

Robert Wiblin: Are there any recent innovations in nuclear energy, or improvements on light-water reactors of the past, or forthcoming potential innovations that you could talk about that might get people more excited about it?

Mark Lynas: Yeah. I really like some of the molten salt reactor designs. It just makes more sense to have your fuel liquid rather than having your fuel solid and trying to stop it turning to liquid, which happens in the conventional light-water reactor where meltdown is the most fearful thing. If your fuel’s already liquid, and it’s mixed with salts, and that’s where the fission’s taking place, that just makes a lot more sense. It also makes more sense not to use water as your coolant, because then you’ve got to have a pressurized environment. If you’re going to have water at 300 degrees centigrade, then the whole system has to be at a very high pressure. And then if everything goes wrong, it’s very difficult to get in there and do anything, because whatever’s inside is trying to get out the whole time.

Mark Lynas: And so just by the design of the thing, you’ve got a more difficult safety environment if you’ve got pressurized water at 300 degrees and you have a loss of pressure or loss of power or anything like that. So light-water reactor design, which we were left with in the ’40s for submarines pretty much and then became the standard for civil nuclear power, isn’t at all the best. If you’re going back to first principles, you would not design a nuclear fission reactor that way. And I quite like also the fast breeder aspect of thorium in that you’re breeding more fuel into existence. And by the way, there’s enough thorium to run the planet, even at US standards of living for like 10,000 years. Really is not a limited resource in fuel sense.

Mark Lynas: And the designs have this very clever freeze plug thing where, let me get this right, you have to blow very cold helium on it, and that keeps the salts frozen at the bottom. So for some reason you get a loss of power, that stops happening and it thaws out, and then all of the fissioning molten salts drain into all of these very separated tanks, which are passively cooled. And there’s nothing you can do actually to make it blow up, even if you were to try. Whether that would persuade people who are fearful of the whole concept of radioactivity and the atom, I don’t know. Possibly not. But I would quite like to have reactors out there which were passively safe. I think it’s just a better prospect.

Robert Wiblin: Yeah. This has really inspired me to go and really investigate these things more properly, because how nuclear power actually works and what the possible advances are has always been a bit of a blur to me. People talk about them, but I don’t really have an ontology in my mind of the different choices that we potentially have to make. Are there any sources that you can recommend if someone really wants to get up to speed on where we are with nuclear energy today, what the problems are, and what the possible solutions are? Where might they go?

Mark Lynas: Oh, that’s a good question. And so some of these new companies actually have good videos and just explain how the whole thing works. But there is this sort of debate between the light-water reactor proponents and the advanced design crowd, the fast breeder crowd. But I think ultimately we have to go in that direction. There’s not that much uranium-235 out there. It makes sense to use this stuff a bit more productively.

Robert Wiblin: Sorry. Explain that.

Mark Lynas: So natural uranium in the ground, as an ore, which you obviously purify to make into nuclear fuel, is a natural concentration of uranium isotope 235, and only about 0.5%. The rest of it’s uranium-238. And having those extra neutrons means that uranium-238 isn’t fissionable. So only uranium-235. So this is what the Iranians are doing with their centrifuges, is to try and increase the proportion of uranium-235 so that you can get to where you need to be to build a bomb, where you need over 80% uranium-235. So you get it from 0.5% to 80%. You do that through centrifuges which are spinning gas containing uranium, so the heavier stuff goes to the outside and the lighter stuff goes in the inside. And you do that through several thousand centrifuges: you can gradually increase the proportion. So uranium-235 is the fissionable isotope, uranium-238 is non-fissionable, but comprises 99.9% of what’s out there.

Mark Lynas: So you have to enrich uranium, which is doable, but then you’ve obviously got the issues with controlling proliferation risk and stuff like that, because it’s the same stuff. But you only need it to be like 2% enriched to make nuclear fuel, whereas you need 80% too much to make nuclear bombs. So there’s enough difference between them that it’s very easy actually to figure out when a country, some rogue state is trying to do that. The only complication is plutonium here. So in a reactor, uranium-238 will capture a neutron and transmute to plutonium-239, which is also fissionable and which is also a component for nuclear weapons.

Mark Lynas: So I think the Trinity bomb or the Hiroshima bomb in 1945, one of those was plutonium; one of those was a uranium weapon. So actually a lot of the fission that goes on within any nuclear reactor is uranium-238, which is turned to plutonium-239. Potentially, if you get that out and find a way to purify it and concentrate it, you could then have a proliferation risk that a weapon could be created. So this is one of the objections that people sometimes raise. But actually, if you can turn uranium-238 into plutonium, then again, you’ve got pretty much inexhaustible fuel supplies. So to my mind, that’s a reason to be more enthusiastic about nuclear than less, because you can run a highly energy consumptive, developed civilization for centuries, millennia using this sort of fuel without destroying the climate.

Arden Koehler: Why are you less worried than some other people about the proliferation concerns?

Mark Lynas: You just have to keep control of the fuel cycle. This is what pretty much already happens. Every country doesn’t make its own nuclear fuel. It’s traded stuff because it’s quite specialist, requires a lot of difficult, complex equipment to make. So you have a few places which make it, and then oftentimes they take back the waste and maybe process it or whatever. But either way, the whole fuel cycle is safeguarded within internationally regulated scenario. That’s what part of what the IAEA exists to do.

Careers [01:54:28]

Robert Wiblin: If there’s listeners out there who are listening to this, and they read your book, and they’re like, “Yeah, nuclear is the way to go”, what opportunities are there for them to make a difference? Do we need advocates or people to go into engineering or business? What can we push on here?

Mark Lynas: We need all of those. We need enthusiasts. We need engineers. We need innovators. We need activists. We need everybody who’s interested in this issue to be out there and talk to their friends about it. You remember, this is a cultural awareness shift that we need more than anything. Yes, the engineering challenges need to be addressed too. But imagine if there was like 80% of people were enthusiastic about nuclear, and we were putting a few billions into research, and everyone was supportive. It’s a bit like making a COVID vaccine. It would be this big project that everyone would be excited to be involved in. Imagine how different that is from the current situation where it’s this kind of hideous thing.

Robert Wiblin: Almost taboo.

Mark Lynas: Yeah. It’s really expensive, but we’ve got to do it, because whatever.

Arden Koehler: So does that mean that we maybe especially need people doing advocacy? And if so, are there particular types of advocacy you would guess are especially effective for persuading the people who need to be persuaded?

Mark Lynas: Yeah, we need a pro-nuclear Extinction Rebellion. And if Extinction Rebellion was to carry through its mandate properly, it would be pro-nuclear. It’s one thing to put pink boats into the center of London and say, “We’re in a climate emergency”, but then people say to you, “Well, all right. What do we do about it?” They say, “Well, we don’t do solutions”.

Robert Wiblin: Are there any companies, or organizations, or maybe university research projects that you’d be really excited for people to go and join?

Mark Lynas: I think actually it’s more of a philosophy. So I would hesitantly call myself an ecomodernist. We wrote a manifesto a few years ago to try and codify this. It’s this evidence-based environmental movement to try and bring scientific rationalism into the green scene and to be progressive, because a lot of environmentalism actually isn’t progressive. It’s very conservative, even reactionary. It’s about going backwards and keeping people poor. They don’t say it in that sense, but pretty much it is.

Arden Koehler: Or they don’t care enough about those side effects.

Mark Lynas: Well, actually I think it’s a defined outcome.

Arden Koehler: Really?

Mark Lynas: Yeah. If you look at the GMO stuff, they don’t want farmers in Africa to drive tractors and use fertilizer. They want them to remain in subsistence, cultivating crops by hand, because they consider that morally desirable. That’s the whole idea behind the organic movement, really, is to try and reduce the amount of technology that’s used in agriculture. Why you do that in a very low tech subsistence region with very low productivity and the constant risk of food insecurity, it isn’t really fair if you’re a well off, rich, well-fed person and then try and externalize that into Africa. But that’s pretty much where all of the engineers and the entire aid budgets have gone.

Arden Koehler: Yeah. Go on. Sorry.

Robert Wiblin: Yeah, Arden always wants to be really charitable. Maybe we can just say there’s some people who feel this way and there’s some people who don’t. There’s a range of views. Given what an uphill battle nuclear has in Europe and the US, are there other countries where maybe advocacy will be even more useful? Maybe in China, people are already more positive about it, or maybe there’s developing countries that need more energy where people are more open to the idea of building nuclear power plants, and that’s where we could really see a renaissance take off.

Mark Lynas: Yeah. That’s a great question. Maybe Indonesia, India, countries which are relatively open, but which have a huge need for clean energy. So yeah. But there isn’t a pro-nuclear movement. There’s no pro-nuclear grassroots movement anywhere in the world. There’s one or two successes like in Finland, for example, the ecomodernists. It’s literally just half a dozen people to start with, but they’ve got an MP elected now who’s a member of the Green Party but has an ecomodernist philosophy. And they’ve got support from all of the different political parties. And Greenpeace has gone quiet on nuclear at least. So you’re at the stage now where it’s flipped over and being pro-nuclear is sort of the sensible position to have in Finland. Now let’s try and get there in the rest of the world.

Robert Wiblin: Yeah. One thing you talked about in the book is modular designs, which might allow us to build plants more quickly, on time, and at lower cost. Do you mind talking about that for a second?

Mark Lynas: Yeah. No, fire away. It’s a bit like how you make ships. And so there’s some people I’ve been working with who actually look at, “Are there ways to make modular reactors in shipyards?” essentially, where you’re building very large pieces of incredibly complex engineering and steel and it’s all put together in the space of a few months. And they roll off a production line, and you’ve got a very highly skilled workforce with all the modern robotics and everything right there in one place ready to produce them. Because even if you do do it with nuclear, it doesn’t make it easy. The scale is still immense. Again, just to throw a number out there, if you were to replace our current global oil consumption with nuclear generated hydrogen, you’d need the equivalent of the entire nuclear fleet produced every single year, which is like 400 and something gigawatts. So are you really going to design and build 400 light-water reactors every single year? I don’t think so. You’re going to have to have a completely transformed approach to the whole production chain, all of the manufacturing process.

Robert Wiblin: What are the challenges there? Or do you think it’s just something, if we put in the effort, we’ll figure out a way of making these smaller reactors in a more systematic way?

Mark Lynas: It’s not only been… Designs are out there. It’s got much further than that, where this Korean shipyard too are already giving quotes to nuclear engineering companies for how much it’ll cost to do this. But you need the first one to be built, obviously, before you can start thinking about the next several hundred.

Robert Wiblin: Actually, are there any opportunities for donation or investment here? People often ask me, what for-profit stuff can I invest in, or what socially responsible investing can I do that would improve the world? And often I don’t have a lot to say to them, but maybe this is something I’ve overlooked.

Mark Lynas: Yeah. Well, go and put some money into ThorCon. I think they only need a few hundred million to get the first prototype, which is peanuts really. And there’s a big jump between a paper reactor, as they say, and one which actually is working and has been through all of the tests, been fully licensed, and is scalable in that sense. So that’s the gulf that needs to be jumped with the advanced designs.

GMOs [02:00:41]

Robert Wiblin: I know you’re also an advocate for GMOs and changed your mind on that. Do they have any role to play in preventing climate change?

Mark Lynas: Hugely, in terms of increasing our adaptive capacity. You were talking early on about how we can avoid famines. And if you want to be in a situation where food crops can still grow in a hotter, drier environment, you’re going to have to change their genetics. How are you going to change their genetics? Well, you’ll need to use genetic engineering. This isn’t complicated for people who understand. And so, yes, GMOs maybe could buy us a decade or two in terms of avoiding the supply shortages that might otherwise arise from low to moderate levels of warming. And also they can make, and are making agriculture more sustainable. If you’ve got insect repellent crops which fend off insect attacks, then you don’t need to spray them with insecticides.

Mark Lynas: There are crops which are disease resistant. So in Uganda, where I was a few years ago, they’ve got a big problem with bacterial wilt in the staple banana crop. There’s GMO varieties of banana already beyond the lab. They’re already in field trials, which could solve that problem basically. But because their GMOs, you’ve got this huge fear mongering campaign which is fully supported by Western aid agencies and NGOs, which has basically blocked up the political process in Uganda so that they probably won’t ever be released. Well done Westerners. You managed to stop Ugandans having disease-resistant bananas. Big round of applause for everyone, I think.

Arden Koehler: So for GMOs, do you think that the main things that listeners could do if they wanted to contribute to adoption would be advocacy again? Or is there something else maybe that people could do if they were passionate about this?

Mark Lynas: Well, there actually is quite a strong grassroots pro-science, pro-GMO movement in Africa and elsewhere, which I’ve been involved in helping to coalesce through the Cornell Alliance for Science. So visit Cornell and join, and become an advocate as part of that network as well. But again, I think so much these days comes down to social media influencing things, and just talk to people. It’s not experts who persuade anyone: it’s your friends and your relatives. And so just talking to people who trust you about this is an incredibly powerful tool and is ultimately the thing that will make the difference.

Robert Wiblin: Do you know if there’s been any research on what messages are most likely to change people’s minds, especially about nuclear energy, but maybe also GMOs? So one thing is, when you talk about this stuff, unfortunately I stopped studying physics in year 10. So I was like 15, and often I feel like my eyes just kind of glaze over when people start talking about the technical details, which makes me feel more sympathetic to people who are just like, “I don’t bloody know anything about genetic engineering. And so maybe it is dangerous”. It’s like, “I can’t follow this conversation”. It’s difficult.

Mark Lynas: Yeah, it is difficult. But then that’s why it ultimately comes down to trust and expertise, because you won’t understand molecular biology. And so you won’t understand nuclear physics. Well, you won’t understand both of them at the same time. You’ve even got different groups of experts who do that. But I’m not claiming to be one of them. So my information comes from what’s published by experts, and it’s the same with climate. You know, you’re not going to understand the physics of greenhouse gases either by your own experiments on a Wednesday evening. So it comes down to their compounded knowledge, which has been generated by experts working over, well, not just over years, but over centuries, actually, in terms of where science came from. And so you can’t gain an understanding of these things from your own anecdotal, personal experiences. So that’s where belief in magic and superstition comes from, is our misallocation of cause and effect, which is a very human thing to do.

Mark Lynas: But if you were to get beyond that and to have a situation where empiricism actually makes a difference, then you have to trust in experts, because you have to trust in the people who come up with the numbers and have explained them. And ultimately that’s the real challenge in any of those areas, is trust. And if you believe the climate scientists are lying to you, then you’re going to vote for Donald Trump; you’re not going to advocate for addressing that problem. If you believe that GMOs are going to poison you, then you’re going to stop Africans being able to use them and address their food insecurity challenges. If you believe that nuclear is this magically, toxic, awful thing, then you’re going to keep campaigning against it and result in more coal emission. So all of this stuff ultimately comes down to people’s willingness to believe in expertise and to have a more empirical and more science-based view of the world.

Robert Wiblin: I know you’ve got to run, so we should probably wrap up. I think maybe a final question is, you think most people are wrong about nuclear or that they’re too worried about nuclear, too worried about GMOs from a safety point of view. What other things are people wrong about? Do you have any other heterodox views?

Mark Lynas: They shouldn’t be heterodox, because that’s where the scientific consensus is.

Robert Wiblin: Completely, yeah.

Mark Lynas: No, yeah. So I’m not a contrarian in that sense.

Robert Wiblin: No, no.

Mark Lynas: I’m pro-vaccine. A lot of it comes down to conspiracy theories, really. To be a climate skeptic, you really have to believe that thousands of climate scientists have collaborated in a conspiracy to lie to us for some reason about climate physics. Same goes for vaccines. It comes down to a conspiracy theory about big-pharma and Bill Gates, and that they’re somehow poisoned with toxic mercury or whatever it happens to be. But that still comes back down to the same thing. Why do people not take in evidence? Why do people believe in conspiracy theories? It’s because they are simple narratives and politicized explanations which kind of lend to distrust of authority, which is valid in many contexts, but not when it results in large scale public behavior which is injurious to the commonality of us all.

Arden Koehler: I’d be curious if there was another sort of technology or something that you think is really underappreciated.

Mark Lynas: Yeah, maybe it’ll be ammonia. Ammonia is interesting stuff.

Arden Koehler: What do you mean?

Mark Lynas: Well, the problem with hydrogen in a hydrogen economy is that it’s very difficult to move around. You have to cool it to 20 degrees kelvin, so 20 degrees above absolute zero to be able to get it liquefied, obviously under very high pressure. So it’s a very energy intensive and difficult thing to do to move large amounts of liquid hydrogen around. So you need to carry hydrogen in a molecular bond. Ammonia’s very good at that. Ammonia’s NH3. So you take nitrogen, which is all around us in the atmosphere, combined with hydrogen: bang, you’ve got a fuel which is liquid almost at ambient pressure and temperature. It has to be a bit cooler, but very easy to do. And you can more or less burn ammonia in diesel engines, or in fuel cells, or whatever. Do either of you know about the exciting prospects for ammonia?

Arden Koehler: I had never heard of it.

Robert Wiblin: No, never heard of it.

Arden Koehler: Which is a good sign maybe our audience wouldn’t have either.

Robert Wiblin: All right. Well, on that positive note, hopefully there’s lots of other technologies there that we can find out about that will improve things. And our guest today has been Mark Lynas. Thanks so much for coming on the 80,000 Hours Podcast, Mark.

Mark Lynas: It’s been my pleasure. The three hours have simply flown by.

Rob’s outro [02:07:55]

Just a reminder: as part of our efforts to improve our climate change content, earlier this year Arden made a medium-sized update to our problem profile on the website, adding more discussion of long-range climate forecasts and the most extreme risks.

You can find that at 80000hours.org/problem-profiles/climate-change/ or the link in the show notes.

The 80,000 Hours Podcast is produced by Keiran Harris.

Audio mastering by Ben Cordell.

Full transcripts are available on our site and made by Zakee Ulhaq.

Thanks for joining, talk to you again soon.

About the show

The 80,000 Hours Podcast features unusually in-depth conversations about the world’s most pressing problems and how you can use your career to solve them. We invite guests pursuing a wide range of career paths - from academics and activists to entrepreneurs and policymakers - to analyse the case for working on different issues, and provide concrete ways to help.

The 80,000 Hours Podcast is produced and edited by Keiran Harris. Get in touch with feedback or guest suggestions by emailing [email protected]

Subscribe by searching for 80,000 Hours wherever you get podcasts, or click one of the buttons below:

If you're new, see the podcast homepage for ideas on where to start, or browse our full episode archive.