Transcript

Cold open [00:00:00]

Hannah Ritchie: One way you can have additional impact is on the signal you’re sending to policies — that you care about the environment, you care about climate change. But there’s also a really strong technology economics signal you’re sending, where if you buy an electric car, you’re showing to the market, “Hey, there’s a big market over here for people to serve. Come and serve us.” Or installing solar power or buying meat substitutes instead.

We need to make these technologies cheaper for people in low-income countries, for them to have as the default option. And by buying those, you’re basically bringing down the cost curve for all of these technologies. So your impact is way beyond your individual thing. It’s like this collective pulling the market in a certain direction.

Rob’s intro [00:00:47]

Rob Wiblin: Hey listeners, Rob here, head of research at 80,000 Hours.

If you’re like me, you’re probably a fan of the website Our World in Data, which is an incredible resource for figuring out what’s going on in the world and which common narratives in the media are legit and which are actually nonsense. We spoke with its founder Max Roser back in episode #103 — Max Roser on building the world’s first great source of COVID-19 data.

Hannah Ritchie heads up its research there, and over the years has published a number of articles I really liked, providing a reality check on biodiversity, population growth, ocean plastics, species extinction, lead poisoning, fertiliser use, the disappearance of bees, deforestation from soy production, and many other things. She’s great on Twitter as well.

In today’s episode, Luisa talks with Hannah about how low agricultural productivity and air pollution are weirdly underrated issues, whether or not humanity is managing to turn things around and save the environment, and why our perceptions on topics like that so weakly track reality.

But without further ado, I bring you Luisa Rodriguez and Hannah Ritchie.

The interview begins [00:02:13]

Luisa Rodriguez: Today, I’m speaking with Dr Hannah Ritchie. Hannah is a senior researcher and the head of research at Our World in Data, and author of the new book, Not the end of the world: How we can be the first generation to build a sustainable planet. Thanks so much for coming on the podcast, Hannah.

Hannah Ritchie: Thanks very much for having me. I’m really happy to be here.

Luisa Rodriguez: So I hope to talk about your book, the ozone layer, and why you think increasing agricultural productivity across sub-Saharan Africa is one of the most important problems this century.

But first, what are you working on at the moment, and why do you think it’s important?

Hannah Ritchie: So currently, I’m still at Our World in Data. I’ve been here for many years now, and there we’re working on the world’s largest problems. So I would hope that would fit the importance criteria. My time is split there between working on core Our World in Data stuff — and that’s ranging from the environmental topics that I cover, to malaria, child mortality: a really broad spectrum.

So that’s my work at Our World in Data, but I’m also doing quite a lot externally from that. I’ve recently written a book. I’ve done a TED Talk. I’m doing some freelance writing. I think a large part of that is that we get a lot of people coming to Our World in Data, but it’s also trying to push out the importance of what we do to new audiences in different formats. So I’ve been doing a lot of that recently.

Luisa Rodriguez: Cool. What does that look like?

Hannah Ritchie: It’s been interesting. It’s quite different from Our World in Data. I mean, writing a book is a very long journey. Doing a TED Talk is obviously a very different form. I’m used to writing, and then going to speaking. Also, a TED Talk is obviously quite a high-stress environment to do that, but it’s trying to get a really succinct argument across without all of the academic fluff, and what I would lean towards trying to add all the caveats. So doing that was a really interesting experience in trying to get to the crux of the core argument that I’m making.

Luisa Rodriguez: Right. Every word is considered and valuable. How did it feel doing the TED Talk?

Hannah Ritchie: It now seems like a complete blur. Like, I practiced so much beforehand.

Luisa Rodriguez: And then you like blacked out?

Hannah Ritchie: Yeah. I mean, the advice was that you know you’ve practiced enough when you’ve gotten to the stage where you can basically do it without thinking. The advice they give you is that you’re giving the talk, but you also need to make eye contact with a different person every few seconds. A lot of that requires intense concentration, so you actually can’t really think about what you’re saying.

Luisa Rodriguez: About the words.

Hannah Ritchie: So yeah, I kind of got up there, and you know, you’re always worried that your mind’s going to blank. I actually can’t remember what I said. I mean, I’ve watched it back, so I know I said what I’d planned to say, but it went by so quickly that it was just a complete mind blank.

Luisa Rodriguez: Wow. It must be such a weird experience. But you watched it back, and you said the things.

Hannah Ritchie: Yeah. I said the things.

Luisa Rodriguez: Yeah, cool. Well, we will be excited to link to that when it’s out.

Why agricultural productivity in sub-Saharan Africa could be so important [00:05:25]

Luisa Rodriguez: Moving on to our first big topic. You’ve written an article that makes a claim that low agricultural productivity across sub-Saharan Africa is one of the most important problems this century. I’m interested in digging into that, and what concrete solutions might make achieving it possible. To start, why is increasing agricultural productivity in sub-Saharan Africa particularly important?

Hannah Ritchie: I should preface this by saying that one of the reasons I think it’s an important problem is I think it’s very overlooked and underrated as a problem.

Luisa Rodriguez: Yeah. It was basically new to me stated that way. I guess I don’t think of sub-Saharan Africa as having high agricultural productivity, but the idea that it might be really pressing, and have big benefits if addressed, was just totally a new idea.

Hannah Ritchie: And I think that because it’s somewhat overlooked and slightly complex, I’m not going to pretend that I have all of the answers or solutions, because I think there’s open questions there that I wish people were paying more attention to.

But my argument for why I think it’s like one of the most important problems this century, I think there are two elements to it. There’s a very human element to it. So if you look at sub-Saharan Africa — and I’m also aware that we’re talking about it regionally, when there’s obviously very large differences across the region — but if you look at sub-Saharan Africa as a whole, around 40% of the population still live on less than $1.90 a day, so below the international poverty line, which is very low. And there’ll be many more that are not that far above it.

And then if you look at the employment across the region, more than half work in agriculture. And if you look at the poorest, it’s estimated that around three-quarters of those that are living in the deepest poverty are farmers, so they work in agriculture. So basically, what we’re saying is that most of the world’s poorest work in agriculture. And the problem they face is that they’re often really smallholder farmers; they don’t have the capital or the money to invest in fertilisers or machinery or to expand their land. So basically, they need labour. It’s often like a family-run farm, where everyone in the family has to contribute. There’s no money to invest in education elsewhere, so they almost get trapped in the cycle where they don’t get a lot from crop production, but everyone in the family has to work there to just stay afloat. Basically, you get locked in. There’s almost no opportunities externally to go elsewhere.

So one of my core arguments is that if you’re going to address global poverty, you have to increase agricultural productivity in sub-Saharan Africa. There’s almost no way of avoiding that.

Luisa Rodriguez: Right. So the idea is that so many of these people that are earning the least in this region, which has many of the world’s poorest, are working in agriculture, but producing so little relative to the land they have that they’re not earning nearly as much as they could. And by increasing their crop yields — which at the moment, they can’t do because they just can’t afford to invest in it — you could lift a bunch of people out of poverty. And that just sounds like a huge win.

Hannah Ritchie: There’s obviously human benefits to it, but there’s also the environmental benefits. One of the impacts of having low crop yields is that you just need much more land to grow your food. And that’s going to be a particularly pressing problem in sub-Saharan Africa, because that’s also where we’re going to see the largest population growth in the next 50 years or so. So sub-Saharan Africa is going to need to produce even more food, and if they don’t increase crop yields, then that’s just going to come from expanding land, often at the cost of forests. So there’s a very strong environmental case for if you want to address deforestation and biodiversity loss, then you have to somehow increase crop yields.

Luisa Rodriguez: Right. You’ve argued that the reason it’s so low in sub-Saharan Africa is because both labour productivity and land productivity are super low. So I wanted to talk about each of those in turn. Can you explain what labour productivity is?

Hannah Ritchie: Labour productivity is basically just how much money — or in this case, crops that you then sell for money — you get out per unit of input. Here, we’re talking about per hour worked, or per worker. It’s basically how much human effort you have to put in to get like a dollar value in return.

Luisa Rodriguez: OK, and that could be that if you’ve got great machinery, your labour productivity might be high, because you can use a tractor as one person, but do a bunch of productive work. Whereas if you don’t have a tractor and you’re using a hoe, your labour productivity might be much lower because you can get less done. Is that right?

Hannah Ritchie: Yeah. Exactly. So I often think about it in terms of tending a garden, where often it’s like really intense work from a human labour perspective. You really need to work really hard and see to it often, and often, the amount you get back is not that much. In that case, your labour productivity is really low, because you’re working really hard and not growing that much. Which, if you’re just thinking about your garden, it’s fine, but if that’s your livelihood, that’s not good.

Luisa Rodriguez: Yeah. That makes sense. And how does labour productivity in sub-Saharan Africa compare to other regions?

Hannah Ritchie: So if we use a metric for it as the amount of value you’d get per worker — so the economic value per person working on the farm — the average for sub-Saharan Africa is half of the global average.

Luisa Rodriguez: Oh, wow. That is much lower than I would have guessed you would have said.

Hannah Ritchie: So it’s like half of the global average, but it’s 50 times lower than you’d get in the UK or the US.

Luisa Rodriguez: I spoke too soon. That’s much more shocking.

Hannah Ritchie: No, it gets worse. If you look at some countries within sub-Saharan Africa, they’re like half of the sub-Saharan Africa average. So there you’re talking about 100 times less than you’d get in the UK or the US.

Luisa Rodriguez: That’s hard to even fathom.

Hannah Ritchie: So you put that in context: the value that an average farmer in the US might create in three to four days is the same as a Tanzanian farmer for the entire year.

Luisa Rodriguez: That is really mind-blowing. And it makes it super visceral to me why this would be a huge problem, both economically and environmentally. Why is it so low in sub-Saharan Africa?

Hannah Ritchie: I think there’s a couple of reasons. One is that the farms are really small, so often the amount of crop or value you get out is quite low. And maybe we’ll come onto crop yields. So with low crop yields, you get not that much out, but also, as you said, you can’t afford machinery, or you can’t afford fertilisers or pesticides, or things that would basically substitute for human power inputs. So it just means you need lots of hands on deck to keep the farm going and keep it at that baseline level of productivity. So you don’t get much out, and you just need lots of people working on the farm.

Luisa Rodriguez: OK, and then the other thing that seems to be really low here is land productivity. Which feels a bit more intuitive to me, is that basically how much crop yield you’d get from, for example, an acre of land?

Hannah Ritchie: Yeah, exactly. So it’s like what most people would call a crop yield. So say we each have a hectare to grow wheat. If you got four tonnes, and I got two tonnes, your land productivity would be twice what I get. It’s just how much you get from a unit of land.

Luisa Rodriguez: I imagine things that factor into that are some things that are intrinsic to the area — I don’t know, the quality of soil naturally, or whether it’s clayey or not — but also things that you could do to the land, like use fertilisers? Are there other things?

Hannah Ritchie: Yeah. So there’s a couple of factors that come into it. One is, as you say, the quality of land. So the texture of the soil, the natural nutrient density, carbon content of the soil, how well it drains: all of these affect how well a crop will grow. But there are also ways that we can change some of those aspects. We can use irrigation or drainage to determine how much water is in the soil. Or we can apply our own nutrients for fertilisers. So there’s natural conditions, but there’s also inputs that we can use to change that.

Luisa Rodriguez: Cool. OK, and again, I’m guessing land productivity is much lower in sub-Saharan Africa. How much lower is it relative to other regions?

Hannah Ritchie: Again, it’s very low. One way we can compare is we would use cereal yields, because most regions grow some cereals. So if you compare the average in sub-Saharan Africa, it’s about half that of India, which is less than half of the global average. So it’s pretty poor. And then if you compare that to richer countries, it’s like four to five times lower. But then again, there are countries within sub-Saharan Africa that will get half again of that regional average. So there are some countries where you’re talking about getting 10 times less per unit of land than in rich countries.

Luisa Rodriguez: So to get the same crop yields in one of these especially low-yield countries, you’d have to use 10 acres per one acre in a really rich, productive country?

Hannah Ritchie: You need 10 times the amount of land. Which again makes the environmental point really clear. Imagine if we globally had to use 10 times the amount of land to produce our crops.

Luisa Rodriguez: Right. Yeah. And why is that? Is it something in particular about sub-Saharan Africa and the kind of natural things about the soil and environment?

Hannah Ritchie: I don’t think so. And the reason for that is that there are examples of some countries within sub-Saharan Africa, or even for particular crop types, where they can get good crop yields. I don’t think it’s just an issue that’s in sub-Saharan Africa, you can’t grow food. I don’t think that’s the case.

There are a couple of reasons why, or it’s quite hotly debated as to what the issue is there. Like, there’s very obvious inputs problems: can’t afford fertilisers, can’t afford irrigation. So there’s a range of they just don’t have the inputs or seeds that they would need to do that.

There’s also this interesting hypothesis — I’m not sure how convinced I am by it, and I’ll give the reason for that — but there’s this hypothesis that rather than it being a supply problem, there’s also a demand problem. Where, say you’re a farmer in sub-Saharan Africa, and you’re growing to subsistence level to feed your family. And you don’t have access to a market to sell any more than that: either you can’t get to the market, or at the market, people can’t afford to buy goods from you. Then maybe you have no incentive to grow any more food than that and raise yields, because you would have to invest in fertilisers and irrigation stuff — which, if you can’t sell the extra food that you’re going to grow, then why would you do that? So there’s this hypothesis that there’s a demand problem, where there’s not accessible markets to sell more.

I get that, and I think there’s probably examples where that’s true. One reason I’m not completely convinced is that it’s not even apparent to me that many farmers are actually reaching subsistence, because so many within sub-Saharan Africa are undernourished, they don’t get enough food to eat. So it’s not obvious to me that they’re actually growing enough, even just to feed and meet their basic needs themselves.

Luisa Rodriguez: Yeah, that makes sense. One thing I learned while reading your work on this in preparation for the interview was that most of the world actually used to have much worse labour and land productivity, that was actually similar to sub-Saharan Africa’s. What were the key things they did to improve that sub-Saharan Africa didn’t end up doing?

Hannah Ritchie: Yeah. That’s true. We think about these low-yielding countries as outliers now, but for most of agricultural history, that was just the norm, that was just the default. And the basic reason there is that our farming was just at the whims of nature. Like water came when it came — you couldn’t really control it; you couldn’t irrigate the soil. You had to just deal with the nutrients that were in the soil at the time because you couldn’t add any more.

What’s really changed there is, one, we’ve been able to invest in irrigation and improved seed varieties and stuff, but a big change for many countries — and we kind of see this inflection point in yields — was like the beginning of the Haber-Bosch process in the early 20th century, where we basically figured out that we could make our own nitrogen fertiliser. For most crops, nitrogen was the limiting factor; it’s why it wasn’t growing. But we figured out that we could add it when we wanted to add it, and that’s been a massive driver of increased crop yields.

Luisa Rodriguez: And why was it possible for the rest of the world to take advantage of that, but not sub-Saharan Africa?

Hannah Ritchie: Yeah. One obvious thing is that it just costs money, so if you have more wealth then you can invest in that. Some other countries have been really successful in subsidising fertilisers because they realise that it’s so important to break this kind of poverty trap, so they’ve subsidised it so it’s much cheaper for the farmer in the first place.

There’s also the pairing of fertiliser inputs with having the right seed varieties. Many countries have gone through this kind of inflection point with basically genetic breeding of particular seed varieties that were really successful. I don’t know if you’ve heard of Norman Borlaug?

Luisa Rodriguez: I have, but for people who haven’t, remind us what Norman did?

Hannah Ritchie: He’s kind of known as one of the pioneers of the modern agricultural revolution. Mexico, I think, was his first big project, where there were big concerns that yields were really low, and demand was massively outstripping supply. Basically his task was to go there and figure out what seed varieties would work. He did lots of intricate genetic breeding to find the varieties that would work in that environment. And then there were the same concerns in India and Pakistan, and he did the same in South Asia.

We just haven’t really seen the same in sub-Saharan Africa. I’m not completely sure why. I think regionally, it’s just even from an agrochemical perspective, which has its critics, but if you’re looking for genetic breeding of particular seed varieties and fertiliser inputs and stuff, it plays a crucial role. And if you look at a lot of agrochemical companies today, sub-Saharan Africa is just not even on their radar. Some of the big companies, for example, would do regional reports and have regional divisions for some of them. It doesn’t even warrant its own region — it’s lumped in with Europe.

Luisa Rodriguez: Oh, that’s really depressing.

Hannah Ritchie: So basically what they’re saying there is that Europe and North America and Asia — and to some extent, South America — make us loads of money. And Africa doesn’t. Therefore we’ll just lump it in with Europe and report it under the European numbers. So I think part of my motivation for highlighting this as a big problem is to somewhat shift the focus.

How much better things could get in sub-Saharan Africa [00:22:36]

Luisa Rodriguez: Yeah. That makes tonnes of sense. If they were able to catch up to other regions on both labour and land productivity, how much of a dent could that make on the issues at stake? I guess poverty, hunger, wildlife destruction?

Hannah Ritchie: I mean, it would be massive. Even if you do projections, just even out to 2030, on the number of people that will live in extreme poverty, most of them will be in sub-Saharan Africa. And as I said before, three-quarters of those that are living in the deepest poverty are farmers.

My argument is that we’re not going to address global extreme poverty unless we fix this, and to me, that’s arguably our most pressing problem we face. It’s just not possible without doing that. There’s also the obvious argument that that’s also where population growth is going to be happening most over the coming decades. And already around 20% in sub-Saharan Africa don’t get enough calories every day; if we don’t improve crop yields there, that’s just going to get worse as the population grows.

And finally, the environmental arguments. Some of my colleagues at Oxford University basically modelled what would happen to habitat loss for different species out to 2050 and what we could do about it. And one of their key findings is that in sub-Saharan Africa, if things don’t change, there’s going to be a lot of deforestation because of low crop yields.

But what we can do — and actually this links back to the question of, is it just that maybe sub-Saharan Africa just doesn’t have the land and stuff to do this — researchers can also calculate what they call “attainable yields,” which is what yields these countries could achieve if they had the right technologies and fertilisers and stuff. And the estimates come out that they could around triple their current yields.

Luisa Rodriguez: Just by changing how much fertiliser they’re able to use, the irrigation technologies they’re able to use, that kind of thing?

Hannah Ritchie: Basically, using existing technologies that we have in a good way, they could basically triple yields. So it’s not that this is not addressable.

Luisa Rodriguez: Right. It’s not a pipe dream. To tie that back to how much their productivity lags behind other countries, where would that put them? I guess it sounds like maybe that would put them on par with India, if I’m remembering the figures correctly?

Hannah Ritchie: Put them a bit above India, actually. But we would also hope that India could increase its yields, because it also has gaps. But it would make a massive difference, obviously. And from an environmental perspective, what these researchers calculated is that if these countries manage to achieve their attainable yields, then basically the habitat loss would be zero, because we just wouldn’t need to use any more land to grow food because they would just meet food demand through increasing yields instead.

Luisa Rodriguez: Wow. That’s amazing. Does that take into account population growth?

Hannah Ritchie: Yes. It takes into account population growth.

Luisa Rodriguez: Nice. That’s amazing. I guess concretely, it sounds like the way to achieve that is doing whatever these scientists found was best to improve yields in terms of whatever these technologies are that would make the biggest dent. I’m both interested in which technologies those were, and also how we actually get those used, given that it’s not happened yet.

Hannah Ritchie: So I don’t think there’s one single thing. I think there’s a bunch of low-hanging fruits, and it’s very context dependent.

I’ve seen very good evidence that one of the lowest-hanging fruits is irrigation. I mean, obviously variable water — whether that’s drought and then followed by flooding, or just continuous drought — is obviously a massive problem in that region, and will actually get worse with climate change. So being able to provide water to the crops when it’s needed is really beneficial.

The other one is fertilisers. As I said, many other countries have heavily subsidised fertilisers, at least for a brief period of time until you can almost break that deadlock. That has come with other issues on the other end, so you often find countries that have really heavily subsidised fertilisers now overconsume the most because they’re so cheap, like farmers just put as much on as they can. But I think there’s really low-hanging fruit there.

Again, I think investment from agrotech in this region is really important. I even think I can make a reasonably strong economic case for them to do so. There’s this starting problem, where currently they might not have the finance to drive the market, but once it gets going, it could be very big. The point there is that that’s currently the region that’s least invested in this technology — so arguably where you have the biggest market — and it’s also where population growth and increases in crop production will need to be highest. So to me, it just seems very obvious that if you could get that market going, it’s massive.

Luisa Rodriguez: Right. So it’s this emerging market. That makes sense. It seems like this is probably just a problem that occurs in many industries that don’t meet the demands of low-income countries: if there’s no initial demand, or little, there aren’t the right incentives to start producing a thing, even though the thing will eventually get big.

Do you know of the types of solutions that can overcome that?

Hannah Ritchie: Yeah. I think it needs to be very early investments, either at a very high discount or subsidised in some way. I definitely think my suggestion here to some is controversial, because there are controversies around the way that many of these companies behave in these markets. There’s always the big backlash against Monsanto, for example, where they basically try to create a monopoly. And I think there would be concerns that some of those relationships could be quite exploitative in the end — where basically, agrotech companies create seed varieties that only work with a specific fertiliser that they then sell — and you could almost imagine farmers getting stuck in another trap.

So I’m very aware of that, and don’t want to overstate that this is some easy solution that doesn’t have issues. But to me, it seems clear that we’re not going to massively increase agricultural productivity there in the region without some of these investments.

Luisa Rodriguez: So what does it look like for this to go really well? Who has to do what? And then how does that trickle down to changing these outcomes?

Hannah Ritchie: The big players are obviously the country governments themselves. And there, I get that it’s difficult when your finances are already constrained on how to allocate resources. But to me, it just seems like this is a really key fundamental problem, and these economies are not going to grow significantly until they address the problem.

Luisa Rodriguez: And those governments are having to do things like subsidise some of these inputs? Or some other types of programmes that address the biggest issues?

Hannah Ritchie: Yeah. One is subsidising or promoting the inputs. One interesting dimension is the market demand problem: how you create an environment, either within a country or internationally, where there is just a really strong market. I think some of that can come from domestic governments, but I think there’s also an international role to play there. You can, for example, change trade tariffs in some way — where you can give preferential treatment or even just equal the playing field a bit — such that there’s larger domestic markets and incentives, but also much larger international markets for farmers to sell into.

Luisa Rodriguez: Right. So lowering the tariffs on crops produced in sub-Saharan Africa might make it so that there’s a bigger market for those smallholder farmers to sell to. And then when there’s a bigger market and they’re earning more, there’ll be this feedback loop where they’re then investing more in inputs.

Hannah Ritchie: Exactly.

Luisa Rodriguez: Yeah. Cool. Are there any other low-hanging fruit, or things that you think should be done right away to make a dent in this?

Hannah Ritchie: There’s also just a large agricultural research dimension. As I said, I found the research on this quite murky in terms of really pinpointing “this is how we have a big impact here.” I think partly because it’s just so heterogeneous across the region, as you’d expect. But I think there is just a large area for research on how particular soils affect the growth of these crops, how different seed varieties fit in, what’s the ideal combination of fertiliser and irrigation, for example. So I think there’s still lots of room for good research.

Luisa Rodriguez: Cool.

The sustainability equation [00:32:26]

Luisa Rodriguez: Let’s go ahead and push on to a related topic then, which is your book. So you’ve written this book called Not the end of the world: How we can be the first generation to build a sustainable planet. It comes out next January, though it’s available for pre-order on Amazon now. And I’m super excited to read it, because I’ve just had the sense for years, especially as a college student, that the environment is just kind of doomed. And it seems like this book is a much more hopeful take on environmental issues than that. Can you lay out the core argument you’re making in the book?

Hannah Ritchie: Sure. I think the book partly follows my own journey, and I think my own journey was probably very similar to yours, where by the end of my university degrees, I was very much in the camp of “We’re completely doomed.” And actually, maybe that was even heightened by, I don’t know what you studied, but I did environmental sciences. So it was just four or five years of getting hit in the face every day with “everything’s getting worse.” And there was very little framing around whether solutions were happening. Like, it was very much like “this is the problem” — and maybe “here’s a few solutions, but the solutions are too slow and they’re not working.”

Luisa Rodriguez: That’s really depressing.

Hannah Ritchie: Yeah. So I think by the end of my university degree, I was very much in the doomsday camp, and actually probably not that far from walking away from doing that stuff, because I felt like maybe there was just nothing I could actually do. Like, it was completely hopeless, and there were these massive problems, and what could little me contribute in any way? So I was actually very close to just walking away and doing something else. I didn’t in the end, and I think the book is really the summary of what I’ve learned over the last seven or so years.

A lot of that I’ve learned through Our World in Data, and really taking in this big picture on how these environmental issues are going to get to where we are now, and then looking at solutions and how quickly they are moving or not moving. I think that’s really shifted my perspective a lot on the fact that these problems — and I lay it out in the book, and I go through environmental problem by problem — they’re big problems, they’re urgent, and I don’t want to take away from that. But I also think that they’re solvable, and we are really starting to see a lot of progress on the solutions. So it’s trying to take this very pragmatic, evidence-based approach. Not this wishy-washy “It’ll all be fine,” but saying these are problems, but I think they’re very solvable. I want to turn the framing around from “We’re doomed” to “No, we can actually solve this if we come together to do so.”

Luisa Rodriguez: Yeah. It probably is important to emphasise that it’s not like you’re denying these are problems. In fact, you think they’re huge and important problems. It’s just that you for a long time thought it was possible that we just really weren’t going to solve them, and you learned more things that made you more optimistic. Is that basically right?

Hannah Ritchie: Yeah. Exactly. Like, if I didn’t think there were problems, I wouldn’t be spending my whole life trying to work on them, and having sleepless nights trying to figure stuff out. So yeah, there are big problems, but I want to turn the discussion around from “There’s nothing we can do about it” to “There really is stuff we can do about it, and what do we actually have to do?”

Luisa Rodriguez: Cool. OK, well let’s get into it. I’ve read the first few chapters of the book and really enjoyed it. Early on, you make the claim that kind of surprised me: that the world has actually never been sustainable. And I just found that really counterintuitive, until I read more about what you meant. Can you explain that?

Hannah Ritchie: Sure. So I get that it’s a controversial claim, and it does seem counterintuitive. I think probably where you came from on that initially, I’m guessing you were thinking about purely environmental sustainability — where you’re thinking about all of the big environmental problems that you face. So the rise in energy consumption and CO2 and plastic pollution, et cetera, has basically happened in the last 200 years or so — most of it probably in the last 50 years. So if you look at those trends, it’s like all this bad stuff has happened in the last 50 years, and before it was all fine, and there were none of these problems. And that’s where I also would have come from, from an environmental background.

And I think when you frame it as that, there’s a large amount of truth to the fact that our ancestors were sustainable. They didn’t have really large environmental impacts. I would say that’s mostly true. There are some areas… Like, it’s not the case that they lived in perfect balance with nature.

Luisa Rodriguez: Yeah. It does seem like one of those things that’s really easy to romanticise. Like, Indigenous peoples didn’t cause harm to the environment; they lived harmoniously with it or something.

Hannah Ritchie: Yeah. And there’s clear examples where there just were large impacts. One key one is if you look at the change in biodiversity — specifically mammal biodiversity — over time, you see that mammals have gotten smaller and smaller. This has been happening over millennia; this is not just the last two centuries. And a large part of that was overhunting, and the humans were hunting. And at the time, the populations were really, really small — like, talking about a global population of maybe 5 million at the time — and more than 100 of the world’s largest mammal species went extinct. And most of that is thought to be through overhunting. So it’s not the case that there was zero impact.

I actually accept the argument that, environmentally, our ancestors mostly lived with a very low environmental impact, and recently that’s been knocked off. But where I would contest the sustainability part is, if you think about why their environmental impact was so low, it’s because their populations were tiny. And the reason their populations were tiny is because child mortality was so high. Half of children were dying before reaching puberty, so you had really high fertility rates — lots of children being born, but half of them were dying — so you basically didn’t really have population growth, and populations were tiny. So my contest there is: Is that really what we’re saying sustainability is?

Luisa Rodriguez: Right. Are we going for a sustainable world where what we mean is we’re not harming the environment because so many of our children die that we’re not growing as a population? That seems like not the goal.

Hannah Ritchie: Right. Yeah. So if you care about human suffering, to me, you also need to consider that in this definition we want to adopt of “sustainability.” So I think my definition there is kind of the definition of sustainable development, which is a kind of newish but also controversial term for some people: we need to have low environmental impacts to protect future generations and other species, but we also need to meet the needs of the current generation. Like, we want to have low human suffering today, but also protect future generations and other species.

So to me, the sustainability equation has two halves there. And I think we’ve never achieved both halves at the same time. Our ancestors might have achieved the environmental part, but they didn’t achieve the human suffering part. We’ve kind of flipped the other way, where we’re doing much better on meeting human needs, but it’s come at the cost of the environment. And my core argument in the book is that I think we could be the first generation that does achieve both at the same time, if we do the right things.

Luisa Rodriguez: Yeah. That is an incredibly hopeful message. I wonder if some people would be surprised or resistant to the claim that you make early on, which is that we are doing increasingly well at meeting the needs of people in the present. I guess I can hear some people thinking that poverty is super widespread still, and millions die from preventable diseases.

Hannah Ritchie: I think there, the distinction is that they might confuse “doing better” with “doing perfect.” And my argument is not that we’re doing perfect — far from it. I mean, a large part of what we do at Our World in Data is highlighting that nearly 1 in 10 people live in extreme poverty, and nearly 1 in 10 people don’t get enough food to eat. So my argument is not that we are there, and we’re meeting the needs of the current generation. But if you look at almost any metric of human wellbeing, it’s gotten dramatically better — whether that’s health, poverty, hunger, nutrition, education — just pick any metric, and across the world it has gotten better.

There’s been large differences in that amount of progress, but there’s also often this misconception that some countries have just made zero progress. And that’s just not true. If you look at the poorest countries today, they still have lower child mortality rates than the rest of the whole world had for most of human history. So everyone’s made progress; it’s just that it’s happened at different rates. And obviously, we want to accelerate it in places where it’s been slowest.

Luisa Rodriguez: Right. Yeah, I just think that’s a really lovely message. And I’m excited to be convinced that we can have both of those halves.

Is climate change the most worrying environmental issue? [00:42:02]

Luisa Rodriguez: The rest of the book is then about the environmental side of things. So you make the claim, and actually, you’ve got a bunch of really helpful data people can look at on how much better the world has gotten from a humanitarian perspective. But then you explore the seven major environmental issues of our time: I think it’s air pollution, climate change, deforestation, food production, biodiversity, ocean plastics, and overfishing. You take each in turn, and you look at where we are now, how things have been going, and what we can do to solve each of them. Which I think is just a really wonderful format.

So I want to talk about a few of them. We won’t have time to talk about all of them, but just to start, is climate change the most worrying of these environmental issues?

Hannah Ritchie: I often lean against the rankings of the issues, in terms of “this is most.” I get why people would want to do that, and I think on other issues, I would do that, because even from a “What do we prioritise? What do we allocate resources to?” [perspective], I get the arguments for ranking.

The reason I don’t really like it in this case is because a lot of the solutions to the problems are the same. So if you want to address air pollution, you reduce fossil fuel use — and that also addresses climate change. Or what you do to reduce deforestation or biodiversity loss also addresses climate change. So a key point is that often the solutions tackle many issues at the same time. I think often people get into this dilemma where they think there’s so many environmental problems, and they seem so complex, that they kind of become paralysed by, “Maybe I’ll change this, and it’ll make climate change better, but maybe I’m having an impact in another way.” So they get paralysed because they think that they’re going in opposite directions, when actually the core solutions are basically the same, and they get us towards the same goal across the different issues.

Luisa Rodriguez: Right. Yeah. Can you give an example? I feel like I have had the experience of being like, I’m going to improve my own environmental impact by doing one thing. And then I’m like, but maybe that thing is actually in some convoluted chain of events worsening my environmental impact. Maybe a pretend example, that I’m making up on the spot, would be like, if I switched from drinking milk from cows — because I think cows take up a lot of land and also something about methane — to oat milk, maybe I’m totally missing something where producing oats also has a big impact on the environment in a way that I don’t know. Is that the kind of thing people are getting confused about? Are there other examples? Or do you mean something else entirely?

Hannah Ritchie: That’s exactly what I mean. Yeah, that example actually comes up a lot. And by the way, to answer that question: all of the plant-based milks have a lower environmental impact than cow’s milk across all the metrics.

Luisa Rodriguez: Amazing. So it’s just simple.

Hannah Ritchie: So win-win across the board.

Luisa Rodriguez: Nice.

Hannah Ritchie: A common one is the soy argument, where people have heard a lot of scary stories about soy and deforestation in the Amazon, so they think, “If I reduce my meat consumption, but I replace it with these soy-based plant-based products, I’m going to increase deforestation on the Amazon. That’s not going to be sustainable.” But actually, the core point there is that in most of the world, soy is fed to animals rather than used for direct human consumption. So that’s just not an argument against that. But you can see why people would get into that paralysis, where they don’t actually know what to do in the end.

Luisa Rodriguez: Yeah. Cool. So it sounds like in lots of the cases that you’ve looked into — and my impression is that you’ve looked into many of them — the theme tends to be that you can make individual choices, and you can find solutions that are kind of bigger than the individual level, that don’t require these really tough tradeoffs. In fact, often there are good things to do that are good in a bunch of different environmental directions.

Hannah Ritchie: Yeah. But away from that detour, and to get back to your initial question on whether climate change is the most worrying environmental issue: I mean, it depends how you frame it.

If you frame it from a human risk, impact-on-suffering perspective, then right now, it’s not. Right now, the biggest issue is air pollution. So if you quantify it on the basis of how many people die, or health impacts, it’s air pollution, where you’ve got 7 or 8 [million] — there’s a range of estimates, but they’re in the millions — of people that die from air pollution. Climate change is not having that impact currently. And there’s obviously a big future risk, but if you’re looking purely on a quantitative basis now, I’d say it’s air pollution.

Luisa Rodriguez: Wow. Yeah. I guess I’ve heard air pollution discussed here and there, but it’s interesting to me that it’s causing so much more harm, at least right now. And I feel like I’ve heard, I don’t know, 1% as much about air pollution as I have about climate change. I guess that might still make sense if, projecting out, climate change is going to cause a bunch more harm, but that does still feel surprising to me to hear.

Luisa Rodriguez: Do you mind saying a bit about what makes air pollution so bad? I guess I have the vague sense that it causes health issues, but I don’t really know the scope of it, and I don’t really know what kinds of health issues we’re talking about.

Hannah Ritchie: Right. On air pollution, the evidence and research around it is emerging more and more every day. It seems to be every week we hear a new study about a new link between air pollution and other impacts that have been found. But the core impacts that we’ve known about for a long time are mostly related to cardiovascular health. I mean, there are a range of air pollutants that are harmful, but really small particles, which we would call PM2.5 — so 2.5 microns in diameter, so really tiny — the fact that they’re really tiny means they can really get lodged in your lungs and your airways. So there’s very strong links between air pollution and cardiovascular disease or respiratory diseases, stroke, et cetera — where basically it increases the likelihood that you would die or have health issues from these mostly respiratory issues.

Luisa Rodriguez: Got it. And do you have a sense of, in countries where air pollution is really high, how many deaths it’s causing per year, for example?

Hannah Ritchie: I don’t have specific country figures, but globally, there’s a range of estimates, but the most commonly quoted are the WHO, I think, quotes around 7 million deaths per year globally — it’s in the millions, just the debate is around how many millions. And I think, actually, as our understanding of air pollution evolves, it tends to be that the estimates go up, we tend to think that we’ve underestimated the impact of air pollution on health in the past; it tends to update upward.

Luisa Rodriguez: OK, and that’s because we learn that more and more deaths can be attributed to air pollution once we understand more about specific health issues and how they’re linked to these pollutants or something?

Hannah Ritchie: Yeah. Exactly.

How we reduced outdoor air pollution [00:50:03]

Luisa Rodriguez: If you project out over the next 50 years or so, does it seem like climate change is going to swamp that? Or do you think air pollution is just generally kind of underrated as a problem area?

Hannah Ritchie: I think it’s underrated as a problem area. I think air pollution and climate change in many ways just go together. As I mentioned, the solutions to climate change and air pollution are very similar — so if we address one, we address the other one. We basically have the option: Do we want to tackle climate change and air pollution in the next 50 years, or do we not? It’s almost like a binary.

Luisa Rodriguez: Right. Well, that seems like great news. And again, not what I would have expected.

Hannah Ritchie: I think that’s also where we’ve seen just a lot of progress. And I think that a lot of that progress, we just don’t see and we just don’t acknowledge. In rich countries, for example, I think a lot of people would have the impression that this dense city of London, for example, is like bumper-to-bumper cars and taxis, like pollution spewing out of the cars. It is very easy to imagine that pollution levels are almost as high as they’ve ever been. In reality, the air in a lot of rich countries is the cleanest it’s been for centuries, and that’s just often a perspective that we lose. And I think there’s a tonne to learn from how we did that, and also to apply to other countries.

Luisa Rodriguez: Yeah. I’m curious what we’ve done right in rich countries.

Hannah Ritchie: I think there’s a few things. I think on the issue of air pollution overall, there’s two aspects to it. One is the rich countries’ outdoor air pollution. There’s also a big indoor air pollution story.

Luisa Rodriguez: What’s that story?

Hannah Ritchie: So it’s often just a really underrated problem, where still millions of people die from indoor air pollution. So if you burn, for example, wood or crop waste or dung for cooking or heating — which is the reality for a lot of people on very low incomes in the world, and was the same for most people throughout history — then you generate a lot of indoor air pollution. And that is really bad for human health. Still millions of people die every year from it, but it used to be much worse. We’ve made amazing progress on that.

Luisa Rodriguez: And how have we done that?

Hannah Ritchie: The biggest thing is just lifting people out of poverty. Like, they use those fuels because they don’t have access to cleaner gas to burn or electricity. So it’s really about them climbing what we call the “energy ladder,” where they go from these dirty sources to cleaner ones. And a big part of that is just having the money and resources to do it.

Luisa Rodriguez: Cool. So that’s just been kind of a side effect of work on poverty that’s been done. Is there more to the story on indoor pollution, or is that kind of the central thing? And aside from that, it’s working on outdoor air pollution?

Hannah Ritchie: I think that the central thing is it’s a very unknown problem.

Luisa Rodriguez: It does feel super unknown to me. Do you happen to know what kinds of numbers we’re talking about?

Hannah Ritchie: If you look at the change over time, since 1990, we’ve halved global deaths from indoor air pollution. But I think still two to three million a year are estimated to die from it. So there’s very low-hanging fruit to save millions of lives.

Luisa Rodriguez: And is the thing to do there still if you help get the poorest people out of poverty, they’ll have access to cleaner energy sources?

Hannah Ritchie: So there’s a couple of ways to do it. One is just to reduce poverty, which is quite a high ask, I guess. There are some ways to do it, for example, by funding cleaner cooking stoves, which make some difference. I think there are a couple of RCTs that show good benefits there. I think maybe some of the research is lacking on just what the actual benefits of switching to these are.

Luisa Rodriguez: Yeah. Should we turn to outdoor air pollution? What’s the story there?

Hannah Ritchie: A lot of countries have made a lot of progress on it. The most dramatic decline has happened in rich countries, but we are now starting to see that in more middle-income countries — in some cases, very, very fast. China is a good example, where for some of their air pollutants, they’ve reduced emissions by two-thirds. And you’re talking about less than a decade: like seven years to two-thirds reductions.

Luisa Rodriguez: That’s amazing.

Hannah Ritchie: It is possible to do it very quickly.

Luisa Rodriguez: How have they done that?

Hannah Ritchie: There’s a couple of ways that rich countries and other countries can do it. One is just the standard reducing fossil fuel burning. So the UK, for example, used to basically entirely run on coal. Basically, we have none. The air pollution benefits of getting rid of coal have just been absolutely massive. But there’s also other stuff we can do, where if we don’t want to get rid of fossil fuels, then we can basically just put pollution limits on the power plants themselves.

Luisa Rodriguez: And what do they do when there are pollution limits? How do they reduce pollution in other ways?

Hannah Ritchie: A good example of this is actually acid rain, and how Europe and US and various other countries tackled that. When you burn coal, you form sulphur dioxide, which is basically the precursor to acid rain. This used to be a massive problem, and basically isn’t a problem anymore because we solved it. The way they solved it is they put limits on power plants that said you can only emit this amount of sulphur dioxide. So what you can do in a coal power plant is basically install this technology, which basically scrubs out the sulphur dioxide. So you have your smokestack, and it basically removes the sulphur dioxide, so the stuff coming out at the top of the chimney just doesn’t have sulphur dioxide in it, and you basically completely eliminate it.

So there’s various examples of, if it’s too tall an order to just eliminate your fossil fuels, there are ways to reduce the amount of pollutants that come with burning fossil fuels.

Luisa Rodriguez: Yeah. And I guess I don’t know exactly, maybe you can tell me which countries have the worst air pollution now? I have a guess that India is probably up there. And it sounds like maybe China was, but it’s doing better.

Hannah Ritchie: So there’s this controversial environmental Kuznets curve. If you imagine on your x-axis, you’ve got income from poor to rich, and then on the y-axis, you’ve got any environmental pollutant metric. The theory of the curve is that when you’re really poor, you have really low environmental impacts. And then as you get richer, it rises, and it basically peaks at middle income. Then as you start to get richer, people care about the environment, they don’t want air pollution, so then it starts to fall again.

Luisa Rodriguez: Right. And they have the resources to actually do anything about that.

Hannah Ritchie: Right. Exactly. So the theory is that pollution is often worse in middle-income countries. And there’s lots of environmental issues that this trend doesn’t really seem to fit, but for air pollution, it’s pretty true. So if you look at the most polluted countries, it’s basically middle-income countries.

Luisa Rodriguez: Yeah. That makes sense. And just to make sure I understand the Kuznets curve, does it basically end up looking like a bell curve?

Hannah Ritchie: Yeah. Exactly, a bell curve. And a lot of environmental impacts don’t necessarily follow it. But the aim that we’re kind of looking for is for countries to basically follow a much shallower Kuznets curve than the ones before them. So rich countries, so the UK, for example, went on this really high long Kuznets curve — where it polluted for centuries, a really long time — and basically, what we want to achieve is for countries to be able to go through that process really quickly with a low impact. And obviously, they need to have affordable resources and technologies to do that.

Luisa Rodriguez: Right. So that they don’t spend time in that part of the curve where the incentives don’t make sense for them to prioritise environmental impacts more.

Hannah Ritchie: Exactly.

Luisa Rodriguez: Cool. Yeah. That’s just a really lovely idea and visual. What can lower- and middle-income countries be doing? I guess you’ve already given a great example, which is scrubbing the sulphur dioxide from I guess the smoke that’s coming out of the smokestacks?

Hannah Ritchie: Yeah, Exactly.

Luisa Rodriguez: Cool. Are there other low-hanging fruit that these countries could be adopting?

Hannah Ritchie: So that’s how China managed to basically slash its emissions by two-thirds. They just got serious on doing that. A big trigger for that was actually the Beijing Olympics and the years that followed from that.

Luisa Rodriguez: Interesting. So they were like, “We’re about to have this huge event. We want our country, or some areas, to be less polluted. So we’re just going to throw a bunch of resources at that”?

Hannah Ritchie: Yeah. Although it wasn’t really ready in time. They reduced pollution by a bit, but not massively. And I think it still goes down as the most polluted Olympics ever or something. But it was actually more of the discontent from people in China afterwards, in the years that followed. All of the eyes are on us for the Olympics. We need to get a grip on the air pollution. And then it started to slide back a bit after the Olympics, and then I think people in China were like, “Actually no, we’re not happy. We want cleaner air.” Which kind of sparked China to then put into their five-year strategy that they had these really tough pollution reduction targets. And they’ve actually done it.

Luisa Rodriguez: That’s really cool. And so the thing that people were noticing, were they noticing it on the day to day? Pollution in the form of smog or acid rain or actually noticing it in their breathing? Or were they aware that longer-term health outcomes were worse?

Hannah Ritchie: I think a mix. I think it’s just very visible in many cities. And in many countries, it gets worse seasonally, because it often also goes with the weather. So you have periods where it’s less bad and then really bad winters. For example, in Delhi, in India, you will often get this winter haze and smogginess really bad.

Luisa Rodriguez: So it’s super visible that pollution is bad.

Hannah Ritchie: Yes. It’s very, very visible.

Luisa Rodriguez: So it sounds like China ended up having this kind of cool citizen-led demand for improvements. And it just did it. Do you see something like that happening in some of these other countries?

Hannah Ritchie: I think part of it depends, again, where on the curve they are. People often compare China and India, but economically, like per person, China and India are in very different scenarios. So towards the top of the Kuznets curve, you still have this tug-of-war of “We want to burn more fossil fuels because we need it for energy and to raise living standards.” And it costs money to install scrubbers on these coal plants. So do you want to put that demand on power plants, where it might make energy a bit more expensive? And that’s going to come at a cost. So there’s this kind of tug-of-war.

Luisa Rodriguez: A tension, yeah. How do we, as a world, do this thing that you’ve described as, I don’t know if it’s flattening or compressing the Kuznets curve? How do you get some countries to leapfrog some of that worst long period of high pollution?

Hannah Ritchie: I think the onus has to be on rich countries. The way you do it is to make the low-carbon and non-polluting technologies cheaper than fossil fuels, so there’s actually no dilemma about whether you go for the coal or the oil or the gas — because solar and wind or nuclear are already cheaper. So there’s just absolutely no need to go through the pathway; you can get cheap, affordable clean energy without having to make that tradeoff.

And we’ve seen amazing progress on reducing the prices of these technologies, where they are pretty much there. A lot of that has come from investing in it very early when they were expensive. And it’s only really rich countries very early on a couple of decades ago that had the resources to do that, but it has completely absolutely slashed the prices of these technologies. And the hope is that then they’re just completely affordable for other countries.

Luisa Rodriguez: Cool. Is the main problem to solve sulphur dioxide in particular?

Hannah Ritchie: No, that’s just one example. So that’s the precursor to acid rain. Some of the other ones that are bad for human health are what we call NOx — so you get that from power plants and industry, but you also get that from fossil fuel cars, for example, where you get that out of the tailpipe.

Luisa Rodriguez: And that’s nitrous oxide?

Hannah Ritchie: Yes. Exactly.

Luisa Rodriguez: And that’s bad for health. Do you solve it with the same kinds of scrubbers, or is it a different technology?

Hannah Ritchie: No. Completely different. But there, the story is kind of similar, where we basically just put regulations on car manufacturers and said there’s a limit to how much can come out of the tailpipe, and you need to find a technology that reduces that. And I’m sure you probably heard the Emissionsgate scandal, where manufacturers would try to basically game their way around some of these regulations. But generally, these regulations have been very effective. They haven’t reduced them to zero, which is why moving away from gasoline cars is beneficial, but they have significantly reduced pollution.

Luisa Rodriguez: Got it. So there’s some cases of getting around these things that are not helpful and are extralegal. But for the most part, these kinds of regulations have worked well, and the regulations really are incentivising pretty impressive improvements to technology. Is that a reasonable summary?

Hannah Ritchie: I think that’s reasonable. I think there’s always the argument that they should be more stringent and that we should be doing more. I think people are often somewhat down on the role that policies can play. But I actually think there’s loads of examples where it’s just played a massive role, and you just wouldn’t get that from technological change alone. You need this combination. Often, you need the policies to drive the technological change in the first place.

Luisa Rodriguez: Is that a theme? Is that a theme throughout the book, where probably there are technologies that we can come up with to solve some of these environmental issues, but a key way to get them is by putting in place policies that incentivise the development of those technologies?

Hannah Ritchie: Yeah. I think the economics and the political ends often go very closely together. I often get the question from people of changing individual behaviours. Like, what impact does it actually have? And am I wasting my time because it’s all about systemic change? Or you hear this argument often from countries, some of them very rich — like the UK, for example, where people say the UK only emits 1% of carbon emissions; what we do just doesn’t matter in the scheme of things. But the key argument I’m making — whether it’s talking about individual changes or changes for countries which now are quite small emitters — is that the impacts they have really have these large spillover impacts on policies, but also on the economics of the technologies.

So an example of that on an individual level is like, one way you can have additional impact is on the signal you’re sending to policies — that you care about the environment, you care about climate change. But there’s also a really strong technology economics signal you’re sending, where if you buy an electric car, you’re showing to the market, “Hey, there’s a big market over here for people to serve. Come and serve us.” Or installing solar power or buying meat substitutes instead: what you’re doing there, as we discussed, we need to make these technologies cheaper for people in low-income countries, for them to have as the default option. And by buying those, you’re basically bringing down the cost curve for all of these technologies. So your impact is way beyond your individual thing. It’s like this collective pulling the market in a certain direction.

Luisa Rodriguez: Right. OK, so the argument is something like, you might not think it’s that important for you to buy an electric car from your own environmental perspective — because generally cars in the UK have technology built in them that means you won’t be emitting loads, even if you have a non-electric car — but if loads of people in the UK buy electric cars, then the electric car technology just gets really good, and drives the price down. And if the price is low enough, other countries, lower- and middle-income countries, might eventually get to just go right to the electric car and skip over some of that intermediate step where they’re polluting loads.

Hannah Ritchie: Right. I mean, I think that wasn’t strictly true, because cars in the UK might have lower local air pollutants, but they still emit a lot of carbon. So it’s not that they don’t have a lot of carbon. But yeah, that’s the core of the argument: that basically what pulled these prices down was people buying them when they were really expensive. And that’s the only reason that they’ve come down in costs, is because they were being deployed because people were buying them when they were expensive. And we never would have seen these costs decline if we hadn’t invested in them early.

Luisa Rodriguez: Yeah. That feels really cool to me as a way… I guess I had not had the visceral sense that rich people in California all buying Teslas was that important for the world. But I guess if it’s creating this flow-through effect where it makes Teslas and the technology that makes Teslas possible much cheaper, then they will just eventually exist elsewhere in the world much sooner than they might have otherwise.

Hannah Ritchie: Right. I mean, the price decline on these technologies is enormous. For example, if you look at batteries, the big hurdle for electric cars for a long time was the cost of the batteries. So if you go back to 1990, I calculated the cost of a Tesla battery that you’d use in a Tesla car today would have cost like $1 million. And it now costs like $13,000.

Luisa Rodriguez: Wow, that is amazing.

Hannah Ritchie: And so I often when I think about climate action, I’ve been really frustrated by how slow progress has been, and it seems like we’ve not been making progress. But when you think about the cost of these technologies a couple of decades ago, it’s very obvious why weren’t making a lot of progress. Like, no one was buying a car that costs £1 million for the battery. And it’s the same for solar and wind, for example. They were just way too expensive for the world to adopt.

And part of why I’m so optimistic is because all of these technologies are now very cost-competitive. It’s just a completely different situation from where we were even a decade ago, where it just seemed completely unfeasible that the world would pay loads of money to install them. And now it just seems obvious, because they’re actually, in many cases, cheaper. Like, the cost of solar panels has fallen by more than 90% in the last decade. In the last decade.

Luisa Rodriguez: So bringing it back to air pollution then, it sounds like you’re hopeful that this kind of trajectory that we’ve seen with some technologies will happen again. And the technologies that will make middle-income and low-income countries be able to cross this Kuznets curve for air pollution in particular faster and more easily than other countries have will be kind of developed as richer countries keep improving on the technologies that make air pollution a much smaller problem. Is that kind of the default outcome? Do you have a guess at how long it will take?

Hannah Ritchie: I think that’s mostly the case. I think even because the costs of these technologies have fallen so much — like, a decade or a couple of decades ago, it was mostly rich countries that were investing in them. Now it’s swinging a lot. because they’re now much cheaper in China, for example. It’s moving also towards upper-middle-income countries that are also really investing.

So China, for example, I think people don’t understand or can’t get their head around how quickly China is moving on renewable energies, for example, or electric cars. Like, really, really, really quickly. I think they are because they’re seeing very clearly that it’s not an economic sacrifice anymore; it’s an economic opportunity: these are the markets that are developing, and if you want to get in, you want to get in there first. And I think they’re seeing that as an opportunity.

Biodiversity [01:12:50]

Luisa Rodriguez: OK, setting aside air pollution now, it sounds like one of the other environmental problems that you looked at, that is going particularly badly, is biodiversity. Can you say more about what you learned that made you feel more worried about the state of biodiversity?

Hannah Ritchie: So I think biodiversity is a very challenging one to cover. It was even a very hard one to write up, because it’s just so hard to measure global biodiversity.

Luisa Rodriguez: I bet. How do you do it? It seems like there are countless species, and we don’t even know how many we’re unable to count.

Hannah Ritchie: Right. So you have more than a million species known. There’s probably several more million that we don’t really know and can’t study. Of course, with every species, you then have however many more populations within those species in different places and locations. So you’re talking about just millions and millions and millions of populations to track. And how do you possibly do that? But also, from that, find a way of communicating to people what’s happening to biodiversity and then also trying to work out how we fix it, how we solve it. So it’s very, very difficult.

I mean, I didn’t go into it with very high expectations that I would find a lot of good news, and I didn’t come away with tonnes more good news. There are particular examples of cases where biodiversity is improving or is stable, but very much most trends are going in the wrong direction.

Potentially why I’m most worried about that is that basically, to tackle biodiversity loss, there’s not many really particularly unique solutions there: it’s basically tackling all the other environmental issues that we’re facing, right? The threats to biodiversity are deforestation or habitat loss for food production or climate change or overfishing. So basically you solve the biodiversity problem when you solve all of the other problems. It’s almost contingent on us being able to do the other stuff, which might mean that we succeed on that last maybe on the list.

Luisa Rodriguez: Yeah, that makes sense. There’s not much that’s super targeted toward just biodiversity that’s much more effective than just solving the other problems.

Hannah Ritchie: Right. Like there’s stopping biodiversity loss, which is tackling all the other problems. There are some positive signs of unique biodiversity stuff — for example, reintroducing species or restoring populations. In Europe, for example, if you look over the last 50 years, there’s been this comeback in many large wild mammals, and some of that is from deliberate reintroduction. So the Eurasian beaver, for example, has been reintroduced in 24 countries. Or the European bison, which was basically on the brink of extinction: it was extinct in the wild, and we’ve managed to basically bring it back from the brink. So there are particular examples where you can do really focused biodiversity stuff. But you don’t stop losing it until you tackle all of the other problems.

Luisa Rodriguez: Right. I wonder if we should take a step back and talk about why biodiversity matters in the first place. I have a sense that people care about it for different reasons. For example, some people care about it intrinsically, because they think it’s inherently good for there to be a wide range of plants and animals in the world. And then others seem to care about it more instrumentally, so they care about maintaining biodiversity because different species do different valuable things for parts of the ecosystem that humans value economically or that they just enjoy. Why do you care about biodiversity?

Hannah Ritchie: I think actually probably a mix of the above. I think I’ve always wanted to come up with this crux argument that everyone buys into and I can really summarise clearly why biodiversity matters.

The scientist in me always wants to put forward the more instrumental argument of we need biodiversity to have a livable planet for our food production or water systems, et cetera. And that’s certainly true: we do need that, and there are very obvious reasons why we need to protect biodiversity in that way.

But I think that that often sometimes disconnects with how we feel about it or how we prioritise stuff. So I would make that argument, but I am also very aware that the species that actually do most for that instrumental impact — the bugs, for example — I feel very less protective of the bugs than I do over the cute mammals. So there’s just this emotional mismatch for me as well.

But the instrumental argument is quite obvious, and that is true. I think in some sense, I just need to go over the scientific argument as well and just accept that I just like having this beautiful planet with these diverse species, and it feels really wrong to destroy them and take them away, and we’ve already done a lot of that. And it breaks my heart a bit that we’re continuing to do that, and we will do more of it. So for me, there’s this awkward mix of yes, there’s instrumental arguments, but also our planet is just really beautiful, and we should protect it.

The example I use in the book is that there’s a specific species of white rhino where there’s only two individuals left, and they’re both female. So if we’re going to save them, we basically need to do some fancy science to bring them back, because that’s not going to happen naturally. So this is a really serious situation, where it’s very likely that they would go extinct. And I use it as an example of where I’m often so focused on the instrumental argument — and it’s true that many species contribute to having a livable planet in often complex ways that we can’t identify, so it’s hard to identify this species is doing this and this is not — but I think in this example, if those two last rhinos die, and that species goes extinct, I can’t argue that has an instrumental impact on our ecosystems because it’s obvious that those two are not. But I still feel this really strong emotional pull to protect them.

Luisa Rodriguez: Yeah. That makes a lot of sense to me. OK, so I guess different listeners will resonate with different parts of that, but it seems like you care about them for a range of reasons. So getting on to just how things are going, how would you describe the decline in biodiversity?

Hannah Ritchie: With the caveats we gave of it being so complex to measure, my overall summary from the research is that biodiversity overall is declining, and declining pretty quickly. That doesn’t mean it’s declining everywhere, and it’s declining at the same rate: there are populations that are stable and there are populations that are actually increasing. So it’s not all bad, but the overall trend is definitely downwards. I would say that pretty confidently.

I think there’s just the issue of reporting really single studies and people interpreting them as “this is happening everywhere.” There was a famous insect study where I think they said that the population was plummeting by 90% or something, and it was at this one site of butterflies in Germany. And then that was extrapolated to “this is how fast insects are plummeting.”

And I actually think insect populations are falling very, very quickly. But it’s this complication of — and I actually empathise a lot with the researchers — they also need to get the message across in an urgent way. How do they do that while also being accurate?

Luisa Rodriguez: Intellectually honest.

Hannah Ritchie: Right. And I think that’s overall just an issue with this stuff.

Luisa Rodriguez: Yeah, so it sounds like it’s hard to communicate, but that overall, it feels clear to you that biodiversity is declining and has been.

Solutions that address multiple environmental issues at once [01:21:30]

Luisa Rodriguez: Do you have something like the top three things that will both make a big dent in some of these issues and that also just seem like a win because they’ll tackle several at one time?

Hannah Ritchie: Yeah. The very obvious one is to switch from fossil fuels to renewable or nuclear technologies. There you’re addressing climate, but you’re also addressing air pollution.

The big one on food is to eat less meat, especially beef. There you’re hitting on so many. It’s the leading driver of deforestation: we use half of the world’s habitable land for agriculture, most of it for livestock — three-quarters of that for livestock — so you’re massively reducing the amount of farmland we use, which has knock-on impacts on biodiversity loss. You’re tackling climate change at the same time. So that one hits on many of these different problems.

Luisa Rodriguez: Cool. I guess I have thought of eating less meat as a big win, and also just from an animal welfare perspective. But it’s not occurred to me that it’s just solving six problems at once. That’s really cool.

Hannah Ritchie: I think food in general — and I’ll go on a bit of a tangent — but food in general, really, for me, just sits at the heart of all of these issues. So if you look at the impacts of food production, food production is responsible for between a quarter and a third of greenhouse gas emissions. Fossil fuels, obviously we need to address, but we also won’t solve climate change without changing our food systems in some way.

Seventy percent of freshwater withdrawals are used for farming. When people think about water, they imagine their shower and brushing their teeth, but most of it is agriculture. We use half of the world’s habitable land for growing food. The world is basically a giant farm. It’s the leading driver of deforestation. It’s the leading driver of biodiversity loss. We have problems with overfishing. Again, that’s about producing food. To me, it just sits at the heart of all of these issues.

Luisa Rodriguez: Fascinating. I would not have guessed that. Were there a couple of other low-hanging fruit or just really powerful solutions for addressing several of these problems at once?

Hannah Ritchie: Yeah. Another big one is we just need to get rid of gasoline cars. Whether that’s moving to electric vehicles — which, for people that need a car in some way, is the better option — or the best option of all is not having a car whatsoever and improving public transport and cycling and walking. But we basically need to move away from petrol or diesel cars. And it just has a massive benefit.

Luisa Rodriguez: Yeah. And which problems does that make a big difference to? Is it mainly climate change?

Hannah Ritchie: Climate change and air pollution are the two big ones there.

Luisa Rodriguez: Nice. Cool. What’s another?

Hannah Ritchie: Another one is on the food front: increasing crop yields. So that comes into climate change, because when you have low yields, you have to use more land to grow the food and farm, and that comes at the cost of what you could otherwise do with that land. So it has a climate carbon impact. It has a big impact on deforestation, because you’re expanding your farmland into forests. It has a big impact on biodiversity loss because of basically taking over forests and grasslands and stuff with croplands. And in some sense, agriculture also has an impact on air pollution in some ways as well. So there’s most issues that that touches on.

Luisa Rodriguez: Maybe we should just dive into that a little bit more. It sounds like the solutions you’re most excited about, because they kind of hit several of these areas, are either energy related or food related.

I guess you said that we really need to kind of radically change our food system. I don’t really know what that looks like. You’ve mentioned eating less meat, and so maybe part of it is eating more plant-based food or some other kind of innovative food thing. But is there more to that radically different food system?

Hannah Ritchie: Yeah, I think it’s probably not as complicated as it seems. There’s just a couple of big, massive, low-hanging fruits.

Luisa Rodriguez: Oh, cool. What are those?

Hannah Ritchie: The biggest one is eating less meat and dairy, and there I would say specifically beef. There’s an interesting tradeoff there. Earlier, we talked about tradeoffs, and I think here is one where there’s a very clear tradeoff to me between eating less beef and what you might substitute that for. So I often make the argument that you can switch to a plant-based diet, of course, but some people like eating meat, and if you want to reduce your carbon footprint, a very good swap would be to swap beef for chicken.

And that, to me, comes with a very high animal welfare cost: one, in the number of animals that you’d have to kill, because you have to kill many more chickens to get the same amount of meat you’d get from a cow, but also, to me, it seems like probably the life of chickens is much worse than it is for a cow in terms of welfare standards. So to me, that’s one clear tradeoff..

Luisa Rodriguez: Yeah. And I guess for people for whom eating meat is something they’re not willing to compromise on, that is just a genuinely tricky tradeoff that I’m sure people have very different views on. Where have you come down on it? Or maybe you just avoid both?

Hannah Ritchie: I personally just avoid both, because I don’t want to make the decision. I mean, I think because the environmental impacts are so strong for me, I would probably come down on the side of substituting beef with chicken to lower environmental impacts, but trying to source from the highest welfare chicken producer you can. I know that people would disagree with me on that. And I actually think that the arguments are very strong on both sides. Maybe, actually the optimal is to go for pork if you wanted to optimise between the two.

Luisa Rodriguez: Interesting. Anything else you’re imagining when you’re imagining changing the food system to solve more of these problems?

Hannah Ritchie: So reducing meat consumption overall, it’s very obvious to me that we’re not going to switch overnight, and we might just not get rid of meat consumption completely. Like, we might just always have a world where there’s some meat consumption. So I think there’s massive gains there from the meat that we do produce. There’s definitely much better ways of doing that and much more efficient ways of doing it. So there’s low-hanging fruit there in optimising where we produce the meat to reduce the environmental impact.

The third one is increasing crop yields, which just has massive environmental benefits.

And then the final really big one is just reducing food waste and losses. And there’s two components to it. One is what we call food “losses,” which are almost unintentional losses. That often happens between the farm and reaching the consumer or the retail stage — where people don’t want to lose the food because they’re losing money, but it might go off because they can’t afford refrigeration, or it’s damaged in transport. So there’s various reasons why you would unintentionally lose food. And actually, those losses are pretty high.

Luisa Rodriguez: Really? I wouldn’t have guessed that.

Hannah Ritchie: Yeah. It’s slightly more common in lower-income countries because often the supply chains are just not set up to preserve the food for the chain.

And then there’s what we would call “consumer waste” — where to some extent, it’s kind of deliberate. Like, you have bought it and you didn’t eat it; you made a deliberate decision to do that.

So those are the two elements to food losses and food waste, but both are pretty big. So when we think about food waste, I think we often think about the impacts as like, oh, there’s going to be emissions in the landfill when I put it in the landfill. But the bigger impact is like all of the land, water, energy, emissions you’ve wasted in producing it on the farm. That’s the big impact. Around a quarter of food emissions are actually food that is wasted, so there’s low-hanging fruit there. I think Rob might disagree with me on this.

Luisa Rodriguez: Oh, really?

Hannah Ritchie: We had a debate previously. And by the way, he posted on Twitter and I replied — was it either during the pandemic, or was it when the Ukraine War started? — I think his argument was that having food waste is good because when there are crises, we have slack in the system. Which I get the argument of that. But my counterargument is that if we were really serious about having slack in the system for emergencies or crises, just having food waste is not the way to do it.

Luisa Rodriguez: Just be deliberate about it.

Hannah Ritchie: Like, you would want to have a plan of we’re going to preserve x amount of stocks, and you’d actually get to pick what food it is, rather than it being the remaining —

Luisa Rodriguez: Perishables, or…?

Hannah Ritchie: Yeah. So I get the sentiment, but I think that’s not the way to do it.

Luisa Rodriguez: Interesting. Nice. I appreciate you having the Rob pushback in your pocket. OK, so the things that sound important from a food perspective are eating less meat, increasing crop yields, reducing food waste — both in the supply chain and also at the consumer level. Did I miss any?

Hannah Ritchie: No. I think one I’d add is about what we use to produce our food: fertiliser inputs and pesticide inputs. Where again, there’s a happy medium. I think a lot of people would argue that we just shouldn’t have these inputs whatsoever. That would be a terrible idea, even environmentally. Having these inputs increases yields, so we need less land to produce the food. And actually, we would be in big trouble if we got rid of fertilisers tomorrow.

Luisa Rodriguez: Right. Crop yields would just decline so much that we’d have to cut down forests to produce enough food.

Hannah Ritchie: Right. Exactly. And so my argument is that many countries, especially poorer countries, would benefit from using more fertiliser. But there is the argument at the other end, where lots of countries massively overapply fertiliser — and actually, by learning to use it more efficiently, we could use much less, and it wouldn’t impact crop yields. So there’s definitely lots of benefits and ways that we can basically optimise our fertiliser use — not eliminate it, but definitely use it much better.

How the world coordinated to address the hole in the ozone layer [01:33:12]

Luisa Rodriguez: I want to move to a topic that shows that we can successfully address environmental issues. So you’ve written a great article about a case where humanity was actually able to solve a big, huge thorny environmental issue in the past. And I think you’ve argued that it was our biggest and maybe our only example of a serious global environmental problem that was actually solved. Why is that?

Hannah Ritchie: I think there’s maybe two, actually. So I think the ozone by far is the biggest one we’ve solved, especially because we’ve solved it on this international level, where literally every country was involved.

I’d say the other big one that we touched on earlier was acid rain, where there was just this massive concerted effort, and we did in the end address it very quickly. Acid rain is slightly different in that not all countries have addressed it yet and to the same extent. So Europe, the US, mostly rich countries have done amazing on it, but there’s still work to be done in some regions on it.

But I think ozone is the example of the big international problem where the world got together on this really serious and pressing problem, and actually just made amazing progress on it. So I like to use this example as a kind of story.

Luisa Rodriguez: Yeah. I was surprised by the claim that it was maybe the only one, maybe just one of two. And obviously, it was scary and sad to notice that. Is the issue that when you have environmental issues that are big, that are global, that are international, then cooperation and coordination between countries is usually just so hard that we don’t end up getting everyone to come together and solve the issue?

Hannah Ritchie: I think there’s a couple of issues. One is that it is very hard to get cooperation — and it’s often very hard to get cooperation because global inequalities are so large, and countries are in such different positions. You can see in the example of climate change: you’ve got rich countries that are emitting loads; you’ve got middle- to low-income countries emitting less, but will probably emit more in the future. They still want to grow economically, for very good reason, and they need fossil fields to do that. So it’s like, “Why would you tell us this? Why would we stop doing that to put climate change first?” So you just get very complex dynamics. And I think the other sticking point for many of these other problems is that the alternatives are expensive, and there’s not an easy switch.

Why I think ozone was slightly different — and we can come onto it later — is, one, many of the biggest emitters were also the countries that were most alarmed or maybe had the highest impact from it, so they had a strong incentive to take action. And it’s also that, in the end, there were fairly easy switches that we could make to solve the problem. Which is much easier than completely switching away from fossil fuels, for example.

Luisa Rodriguez: OK, so the ozone layer problem was kind of an example of solving one of these problems on easy mode, but maybe there are still things to learn from this case. I want to go through the whole story to see both what there is to learn, and just because I think it’s really interesting. But we should probably do a little bit of background on the problem of the ozone layer. Starting really basic, am I right in remembering that the ozone layer is important because it basically shields humans and animals from UV radiation that’s harmful to us?

Hannah Ritchie: Yeah, that’s right. I think it’s important to distinguish between what we call “bad ozone” and “good ozone.” So you get ozone close to the surface of the Earth, so pretty much in the air that we breathe in, and that’s what we call “bad ozone” — because when it’s close to the surface, it’s basically an air pollutant that has impacts around that. So we don’t want it close to the surface.

But we also have ozone high in the atmosphere in what we call the stratosphere, which is like around 15 kilometres above the surface, up to around 35. And as you say, the purpose of the ozone up in the stratosphere is that it basically blocks a lot of harmful UV radiation. So it’s partly what makes our planet livable. If all of that UV radiation was beaming down on us, we’d be in trouble.

Luisa Rodriguez: Can you talk me through the story of how we realised that we were creating this hole in the ozone layer?

Hannah Ritchie: Yeah. So I kind of started with a Dutch scientist called Paul Crutzen, who was like an idol of mine. He was a very amazing environmentalist. He was the guy that coined the term — or at least attributed to him as coining the term — “Anthropocene.” He was that guy. He sadly died a few years ago, but had a big impact on environmental science.

So this was in the late 60’s and early 70’s, where there were a lot of theories about what the chemistry of the upper atmosphere was like, what the reactions were like. And a lot of this was theoretical because we just didn’t have the instruments and the technologies to measure it properly. But Crutzen often had disagreements with others on what was actually happening up there. He thought a lot of theories were wrong, and that actually, up in the atmosphere, there was nitrogen compounds and light that could be interacting with ozone to break it down. The problem is that a lot of this was theoretical, and he didn’t really have the experimental evidence that would finalise it and get consensus around it.

Luisa Rodriguez: So he basically just developed a theory that there are things going on in the atmosphere that might mean we’re breaking down ozone, and he had some of the background understanding of why ozone is protective. And so he was like, “This could be a problem,” but he didn’t actually have empirical evidence of it?

Hannah Ritchie: Exactly. At that time, he was most concerned about supersonic jets, because they obviously fly very high in the atmosphere, and they emit these nitrogen compounds that he was really concerned about. And at the time, he was mostly dismissed by other scientists as like, this is just a hoax theory; it’s not really true. So that was his main concern. In the end it actually wasn’t really the nitrogen compounds that were the issue, and the supersonic jets didn’t actually turn out to be a massive problem, but he really laid the groundwork for human emissions — of “Stuff could be depleting the ozone, and this is why.”

Luisa Rodriguez: Right. OK, so he had the theory and he pushed it. And then how did we end up confirming at least some parts of it, that compounds were reacting with ozone in a way that was net negative for humans?

Hannah Ritchie: So partly in tandem, or a few years later from Paul Crutzen doing this work, two scientists called Rowland and Molina, or that’s their surnames, were proposing slightly different [compounds that] also could break down ozone, and that was what we call chlorofluorocarbons — CFCs. These are chemicals we used in aerosol sprays and refrigerants and industry. And they were basically hypothesising the same: that these could react with ozone high in the atmosphere and break it down.

Again, for a long time, they just didn’t have the empirical evidence of it; it was mostly theory based. They did start to not necessarily gain evidence that that’s what was happening high in the atmosphere, but one of the reasons for their hypothesis is that they could basically model the CFCs through the lower atmosphere. And basically what they discovered is that they weren’t breaking down — so they were sticking around, and they were obviously moving up and up and up into the upper atmosphere. So they knew these compounds are ending up high in the atmosphere where the ozone is, and thought they were going to react with the ozone and break it down, but it was several years before they got experimental evidence.

So they shared this, or they bought up their theory, in 1974, when they mostly first published it. And then by 1979, NASA actually started tracking the concentrations of ozone in the high atmosphere. And it was then that they found that year after year, they were starting to see this decline in ozone high in the atmosphere. So it’s a story of several scientists who really had the theory, and the theory actually turned out to be right, but it was several years before we had the experimental evidence that it was actually happening.

Luisa Rodriguez: Cool. Yeah. It just seems like impressive theorising, and I guess advocacy, from the scientists.

Hannah Ritchie: Yeah, I think that’s true. These scientists, all three of them actually won the Nobel Prize for this work.

Luisa Rodriguez: Oh, wow. That’s great. So it was later recognised, even though at first people didn’t know.

Hannah Ritchie: Yeah. At the time, they were mostly dismissed, but they did reap the awards in the end.

Luisa Rodriguez: Before NASA started finding this empirical evidence, it sounds like people weren’t taking it super seriously. Does that mean that there was just no international response? No one was trying to regulate these compounds that were reacting with the ozone?

Hannah Ritchie: There was very little action. There were some stories from the scientists publishing it that this was a problem. And I think some consumers in the US, for example, were a little bit concerned. Really, the action was very little. A few countries banned their use in aerosol sprays, but they didn’t ban them in other sources. And that was mostly brought on because some consumers were starting to shift away from them already, because they were concerned about this problem.

But in the scheme of things, it was very little. The US Environment Protection Agency’s head at the time was completely dismissive of it as a problem. There was obviously very strong pushback from industry. So DuPont, who was the largest producer at the time, they were on it, as, “This is a complete hoax.” They were very much in denial mode. So it was pretty much the scientists versus politicians that didn’t want to hear it, industry players that didn’t want to hear it. So the response initially was very slow.

Luisa Rodriguez: That sounds familiar. What changed?

Hannah Ritchie: I think there were a couple of key things. One is just that the experimental evidence started to build over time. So in 1985, a big report came out of the scientific summary of it, and there was really strong evidence and measurements that the ozone was actually depleting. I think by far, the most striking evidence — what really shook people and woke them up — is that scientists finally captured a picture of the ozone hole over Antarctica. It’s not like they took a picture — they used solar or satellite stuff to capture it — but they actually captured it in 1983. But didn’t publish it until 1985, because they realised how big this was: like, they were going to publish that there was a massive hole growing over Antarctica, so they wanted to be really confident that this wasn’t a measurement error. So they were really careful before publishing.

Luisa Rodriguez: At that point, did people start to pay attention, react? And I guess advocate for something to change?

Hannah Ritchie: Yeah. Exactly. So I mean, we were talking about the ozone hole: it was massive. At the time, it was 10 million square kilometres, which is about the size of the US.

Luisa Rodriguez: Oh my gosh. I actually did not have the sense that it was that big.

Hannah Ritchie: And then it eventually grew to 25 million square kilometres, which is the size of the entire Americas as a full continent. It was really, really massive. So I think the picture hit the front page of The New York Times and everything was a really big “Oh my god. There’s something big happening here.” So the public started demanding that something be done about it.

I think other big changes at the time were significant. So the previous head of the US Environmental Protection Agency, who was really dismissive, was gone. A new person was in, and they were very much, “This is a problem. We need to address it.” So you had the public asking for action, some of the head politicians being like, “Yes, this is a problem.”

But also, importantly, industry had to get involved. DuPont, who was the lead manufacturer of CFCs, their patent ran out. So basically, to some extent they felt exposed in the market because they no longer had their patent on CFCs. So then they kind of played this game of “We’ve run out of market for CFCs; we’re going to take the market for the alternatives.” So they basically made the really strong argument of, “We actually can do this technology in a few years. We can fix this in a few years. We just need the right market incentives to be in place for us to do so. Maybe you should ban the CFCs so others can’t move in and do it, and we’ll take the alternative market.” So they actually played it pretty well.

Luisa Rodriguez: OK, so some of it was really deliberate science, and then some of it was kind of some luck. I mean, it sounds like the patent just ran out, and if it hadn’t, DuPont might have never advocated for banning those compounds. At that point, what happened? What was the action taken by governments?

Hannah Ritchie: So there was some move from industry then that they could actually produce alternatives to CFCs that would maybe not be that expensive. That opened up the case for politicians to say there is actually a substitute that we could switch to if we put the right regulations in place. So a number of countries, mainly the largest producers at the time — so like US, Canada, Europe, Japan, et cetera — they basically formed what we called the Montreal Protocol. That was in 1989. They basically signed this protocol where they said, globally, we want to halve global production of these CFCs within a decade — so by 1999. Which was obviously good, but I think the key thing from that is that even halving by 1999, the limits they put in place in the Montreal Protocol would not have been enough.

Luisa Rodriguez: Interesting. So the limits were not going to be enough. Did they meet them? Did they exceed them? What happened from there?

Hannah Ritchie: The issue is that even halving emissions by 1999, the ozone depletion would have continued. It wasn’t enough to not only stop ozone depletion, but switch it into recovery mode.

So basically, what happened is that they came up with this ratcheting mechanism, where every few years they would reevaluate and increase the ambition over time. And actually, within not that long, by 1992, the agreement that actually switched it from “ozone is still going to deplete” to “we will address the issue,” it was 1992 in Copenhagen. And by that point, they’d increased ambitions for the countries that were in the Protocol, but also more countries were joining. I think they could see this is actually feasible, and it’s maybe economically not that expensive. So more countries started to join.

And the story since then is that, in the end, it got universal ratification — so every single country in the world joined. Basically, we have reduced emissions by more than 99% since the 1980s.

Luisa Rodriguez: That’s amazing. A huge success. I can’t think of really anything, at least in this category, that feels remotely as huge as that. Is the ozone fully recovered? Is it OK now?

Hannah Ritchie: No, definitely not. It’s barely recovered. The hole has stopped growing, so it’s no bigger than it was at its peak, and it’s actually now shrinking a bit.

Luisa Rodriguez: So it’s just starting to shrink.

Hannah Ritchie: It’s just starting to shrink, and it will take many decades for it to fully recover. This will be a slow process. You’re talking maybe 2080 or so before it gets back to where it was. But the key thing is that we’re no longer depleting it. We’ve eliminated the problem. We now just need to leave it and let it recover on its own. So we’ve basically done all that we can, and it will recover if we just leave it alone.

Luisa Rodriguez: I mean, that’s kind of disheartening. These kinds of environmental issues seem to often take decades to recover after you kind of neutralise the problem. And it seems like that kind of thing will be true of climate change as well.

But it seems like from start to finish, meaning from when we noticed the problem to when we got that universal ratification and got to net zero — or, sorry, it wasn’t quite net zero; it was a reduction of emission of those compounds to just 1% of what they’d been? Is that right?

Hannah Ritchie: It was even less than that. I would basically go as far to say we basically just don’t really emit them anymore.

Luisa Rodriguez: Just eliminated. Amazing. And that sounds like it took a couple of decades — three-ish? Is that right?

Hannah Ritchie: Yeah. I guess it depends what your starting point is. Is your starting point when we first saw it was a problem, or is it when we were like, “Yes, we’re actually going to act on it”? I think we’re talking about several decades.

Luisa Rodriguez: I mean, you’d want it to have happened faster, but that still seems promising to me. And so I do feel just very inspired by this story. I’m really interested in what we can learn from it. What do you think is the biggest takeaway for addressing other big global environmental problems that require international coordination the way this one did?

Hannah Ritchie: I think one big lesson is just that, as you said, I think we often see these problems as inevitably, they’re going to take a long time, and action just has to be slow. And I think there’s this problem, but also some other specific examples, where change can happen faster if we actually put our minds to it. So I think it’s not inevitable that progress on these has to be slow.

We addressed this relatively quickly. The acid rain story for many countries was also very fast. If you look at China, when China wants to take action, it works very quickly. And I’m not saying that’s a model that other countries can emulate, for various reasons. But there’s just several examples where it’s clear to me that it’s not inevitable that they have to be slow.

Luisa Rodriguez: Yeah. And probably challenging the assumption that it takes many decades is an important step toward then demanding action be taken much more quickly than it might otherwise.

Hannah Ritchie: Yeah. I think often politicians or policymakers, for example, can get away with the argument of, “It’s just going to take a long time. These things just take a long time.” But I actually think if you can bring real examples where that’s just not the case, then it’s very hard for them to retreat from that. I always make this argument.

Coming back to earlier, where we were discussing relatively small emitters today and what role they can play in actually addressing climate change. There, I think there’s a very clear example of if a country takes action and almost provides a model that other countries can follow, then it makes a massive impact. And there’s the speed thing. For example, you see Norway: nearly all of the cars sold in Norway today are electric, which is just way ahead of anyone else in the world. And it’s done that very quickly. So no other country can use the excuse that they can’t scale electric vehicles very quickly, because we have examples that it’s happening.

Luisa Rodriguez: I guess Norway is really wealthy. So there will be barriers for many countries to doing that.

Hannah Ritchie: Yeah, for the poorest by far, for sure, that’s the case. But even in China, for example, more than a third of new cars sold in China are electric. I would expect within the next three years, maybe, it’s going to be more than half of new cars sold. It’s moving really quickly. So I think there will be examples.

Luisa Rodriguez: That feels like a really compelling example. Are there any other lessons to be drawn?

Hannah Ritchie: Yeah. So I think what’s very clear is that the alternatives need to be cheap; it needs to be very easy for people to replace them. And that’s the argument that I was making earlier: that when it comes to climate change, for example, the alternative energy sources, or even if you’re talking about food, meat substitutes need to be cheaper than meat, and renewable technologies need to be cheaper than fossil fuels. If they’re not, then you’re just not going to get a fast switch.

Luisa Rodriguez: Yeah. If a big difference between this problem and climate change is that the cost to ceasing the use of these chemicals was very low compared with stopping the use of fossil fuels, it might be actually pretty hard to learn much from the ozone case. It does seem really impressive that we got around the free-rider problem, where some countries could have just continued to use the chemicals that were depleting the ozone. And it’s pretty remarkable to me that we got to universal ratification, and it sounds like that was not because of any threats made. Was the main thing that happened was that things just got cheap enough that those countries realised it wasn’t a huge sacrifice to get on board?

Hannah Ritchie: Yeah. I think towards the later stages of that transition, for the smaller emitters or the poorer countries, the market was just almost then set up to not have CFCs in them. So I think the switch then was very easy.

But in terms of how it started and why rich countries took it seriously initially — which is maybe one of the lessons, and is maybe the inverse to some extent of climate change — to some extent, the richest countries had the most to lose, or felt the most threatened by it. And the reason for that is that one of the big concerns at the time from the ozone hole and depleting ozone was the impact that it has on skin cancer. So there were lots of scary headlines at the time of “x number million more skin cancer cases,” et cetera across The New York Times, for example. And skin cancer is more prevalent and you’re more at risk if you have lighter skin, which tends to be at higher latitudes across Europe or the US, for example. So almost the highest risk was for the richest countries that were producing the most. So there, the incentives to reduce were aligned.

Luisa Rodriguez: Right. Does that mean that we should be pessimistic about seeing stronger action taken on climate change until the effects are more viscerally felt in rich countries?

Hannah Ritchie: I think I would have made that argument maybe five or 10 years ago. I just think the argument’s moved on a lot since then. And I think a big part of it comes down the way that I think that countries should see the climate change problem — where in the past, because the alternatives were really expensive, as I said, it seemed like a sacrifice of, “It’s costing me lots of money to replace my fossil fuels with these alternative technologies.” Whereas I think countries are beginning to see that it’s in many senses an economic opportunity.

Another big thing that’s factored into it recently has been the argument for energy security and domestic energy security — where rich countries don’t want to be exposed to volatile fossil fuel markets or be under threat when Russia invades Ukraine, and there’s problems with gas and oil supplies. So many countries are also finding additional arguments to see it as an investment, where they want to be basically in charge of the domestic energy supply.

Luisa Rodriguez: Yeah, cool. That sounds pretty reassuring to me. Is there anything else you think we should learn from the ozone case?

Hannah Ritchie: Maybe one additional one is, from a market perspective, I think it’s just really important to show companies there is a large market for the preferred technology that you want. Like, the DuPont example is they moved in because they saw the market and economic opportunity there and they quickly changed course. And I think in climate change, we are actually starting to see that. You can see it in electric vehicles, for example, where all of the companies are now doing this pivot because they know that if they’re not manufacturing electric vehicles, then they’re going to get left behind. And that wouldn’t have been the case five to 10 years ago. So it’s almost like reorienting the market to show companies there is this massive opportunity, and it’s also aligning with this environmental change that we want to see.

Luisa Rodriguez: I think this is really reinforcing the value of consumer choices to me, which just hasn’t felt as visceral to me lately. Are there any arguments that consumer choice is less important, or is there anything that gives you pause about this idea that having people in rich countries buy the things that are better for the environment, that that’s an important thing to do?

Hannah Ritchie: I think probably one of the counterarguments that I’d see people making is that rich consumers might use these technologies, but just consume more. For example, like energy is getting cheaper, but maybe you just have the rebound where then you just use more energy — so you just have this endless race to ever-increasing energy consumption.

Luisa Rodriguez: Right. Yeah. Do we have evidence one way or the other about that?

Hannah Ritchie: No. Well, there is this energy efficiency rebound effect in some spaces, where if you make your fridge more efficient, you just buy a bigger fridge. Or car examples, where you just get a bigger car.

Luisa Rodriguez: So that is true to some extent?

Hannah Ritchie: It’s true to some extent. If you look at energy consumption across rich countries, it’s mostly not increasing. In fact, it’s actually decreasing in some countries. Decreasing or stable, I’d say, for most rich countries.

Luisa Rodriguez: OK, great. I guess there are a bunch of differences between the ozone case and some of these other environmental issues, but I feel good about drawing some lessons from there.

Surprises from OWID’s research [02:01:59]

Luisa Rodriguez: Let’s move on and talk a bit about your work at Our World in Data. Are there any specific topics that you’d want to cover, but that you can’t because of a lack of reliable data?

Hannah Ritchie: There’s one specific one where I think one of my arguments might change a lot based on if the evidence was different. And for me, that one is microplastics. So my argument around plastic pollution is that the main problem of plastic pollution is not necessarily that we’re using plastic — it’s what we do with it. A lot of people target that to end plastic pollution, we need to end plastic use.

Luisa Rodriguez: Right. Stop using plastic water bottles or something.

Hannah Ritchie: So it’s like eliminate plastic completely. But like, if you actually look at the fundamental problem of plastic ending up in the ocean, it’s a waste management problem. And it’s mostly a waste management problem in middle-income countries, where we’re using lots of plastics but don’t have the waste management yet to dispose of it properly. It’s not that it’s a complete nonissue in rich countries, but we account for a really tiny percentage of plastics that end up in the ocean. And the reason for that is not because we don’t use a lot of plastic — we do, but it reaches landfills, it’s recycled, et cetera. So my core argument there is that the solution to plastic pollution is to manage it better, not to eliminate it.

My argument on that, I think, would have to be different if we saw that there were real detrimental health impacts of microplastics, which come inevitably from plastic use. Currently, I haven’t seen very convincing evidence that microplastics is a big problem in terms of human or animal health. We know that it’s everywhere; there’s a study coming out every week that we’ve found it in Antarctica. So microplastics are everywhere. We still don’t know if they have any notable impacts on health. If they did, then plastic use would be a much higher priority than just stopping the plastic going in the ocean.

So that’s one area that I think is a major blindspot where I would significantly change my mind and my proposition of solutions.

Luisa Rodriguez: Can you give an example of what kinds of products have microplastics?

Hannah Ritchie: People always use the examples of some creams and stuff where they have the little beads. But actually, the main source of microplastics, microplastics is just small plastic particles. So basically, everything in the end breaks down into microplastics. So your big plastic bottle degrades, and eventually it’ll end up as tiny plastic particles.

Luisa Rodriguez: So it’s not that some products use microplastics more than others, or at least that’s mostly not the issue. The issue is that when the products degrade, they become microplastics. And we just don’t have the data on whether those microplastics are causing harm.

Hannah Ritchie: Yeah. Exactly.

Luisa Rodriguez: That’s really surprising to me. In part because I’ve totally heard this idea that they cause harm, and I assumed there was evidence supporting that, but it’s kind of disheartening to realise. I guess maybe it’s one of those hypotheses that could turn out to be right, and then we’ll be glad that people were advocating to reduce microplastics. But it sounds like the jury’s still out.

Hannah Ritchie: Yeah. I think the problem there is the attribution from an environmental perspective. By that, I mean different chemicals and stuff that we’re now exposed to and are in the environment, it’s very hard to discern one single one from the others. So if you see a change in a particular health metric, for example, how do you know it’s microplastics or like some other compound?

Luisa Rodriguez: That sounds genuinely hard, but people are researching it and maybe at some point in the near future, we’ll have more data on it.

Hannah Ritchie: Yeah, hopefully.

Luisa Rodriguez: Another question I have about your work is more about your experience of doing it. What would you say is the hardest thing about what you do at OWID?

Hannah Ritchie: I think some of the hardest stuff we have at OWID — and I’m surrounded by an amazing team, but I think we all struggle with a similar thing — is managing or balancing this point about trying to show that we can achieve progress, and that progress is happening, whilst not falling or being perceived as being complacent at the same time. Like, it’s this mix of the world is getting better, but we still have a lot of work to do. And how do you communicate both of those at the same time?

Or Max Roser, my colleague and the founder of Our World in Data, published this Venn diagram where three statements are true at the same time: The world is awful — we discussed some of the terrible statistics earlier — the world is much better, and the world can be much better. The point is that on most problems, all three of those are true at the same time, but it’s really hard to hold all of those thoughts at the same time. So it’s like, how do you manage people’s expectations or counterarguments around those.

Luisa Rodriguez: Right. I feel like some people feel betrayed or angry or something when you say the world is better, given that the world is also horrible. And convincing them that you’re on the same team — that you still want the world to be much better, even though you’re acknowledging that the world is better than it was — seems like a big challenge. Do you get environmentalist or other groups critiquing OWID, saying it’s just highlighting a positive spin on things in a way that’s going to demotivate people from taking action, or that’s kind of justifying bad behaviour on the parts of governments and individuals?

Hannah Ritchie: I think we get it a little bit less than we used to. We definitely used to be framed as like the “good news guys,” which we weren’t at all. That was obviously not the aim, and if you looked under the hood, that was definitely not the point of Our World in Data. But I think we get that slightly less so.

I definitely still get that on the environmental stuff — like showing that CO2 emissions in the UK have declined a lot, or coal has declined a lot. There’s always the pushback of “Yeah, but they didn’t do it early enough or they didn’t do it fast enough” or some other rebuttal of it. And “You’re actually not helping the issue by highlighting that, because you’re pushing people into complacency.” Which to me just doesn’t seem like a very convincing argument. Like, for people to believe that it’s actually possible to reduce emissions, you need to show people examples that people have reduced emissions. And then you go in and study why that happened. There’s so many lessons in there.

Luisa Rodriguez: Yeah. That makes tonnes of sense to me. I guess people who worry about this framing might think that environmentalist doomerism is essential for keeping people motivated to work on the problems. But it sounds like you think that actually a huge source of motivation is we’ve made progress. We have to make more, but the fact that we’ve made progress shows it’s possible, and that is actually the inspiring thing that will motivate people to do more.

Which definitely feels true of me. I feel more excited about encouraging people to work on these issues, knowing that there are good things for them to do, than I would just being like, “This is a big horrible problem, and it’s not clear that we can solve it, and we haven’t done enough, and we’re not going to do enough. It’s an uphill battle, and you’ll never make any progress.”

Hannah Ritchie: Yeah. I think that’s how I feel. I think one of the issues I see is the lack of separation between how you feel about the problem and your level of optimism for the solutions. So my framing is to push action. People need to be really concerned about the problem to have an interest and be motivated to act in the first place, but I definitely think that you can differentiate that concern for the problem from optimism about our ability to fix it. I think the difference that I have is that so much of the narrative is pessimistic about being able to address it, and I’m more optimistic that we can.

To some extent, I find some of the attitudes there quite weird. People have worked on this climate issue for decades, and dedicated their whole life to it, and often felt like the world was making absolutely no progress — because to some extent, it looked like actually we weren’t really making a lot of progress. But the last few years in particular, we’re really seeing this really rapid uptake in renewables and electric vehicles. It’s almost like we’re at an inflection point — where actually, we’re actually just starting and progress is really happening. And maybe it’s just my psychology, but I find it weird to work on a problem for so long and then see progress actually happening and to not be excited about it, but to be the opposite and still deny that actually anything’s changing.

Luisa Rodriguez: Yeah. I agree. That seems surprising and bizarre. Are there any empirical studies on motivation and whether this kind of doomerism attitude or this optimism attitude create more sustainable motivation? There’s at least the data point of view, but I’m curious if you’ve got either anecdotal evidence or some studies behind this.

Hannah Ritchie: The research on it is not great. I admit a lot of it is based on anecdotes, which is very much against my normal frame of reference. To some extent, anecdotal externally: because of the coverage of our work and the exposure of our work, I just interact with a lot of people in this space, and I pick up on patterns, and I can see arguments. I get a tonne of emails on my inbox from people saying they’ve given up on this problem, they don’t see a way forward for it — some really heart-wrenching emails where it’s really clear that people have just completely given up. So I have a reasonably big bank of anecdotal evidence.

But on the research side, from the reasonable research we have, what’s clear is that people need to be concerned to act — so people need to think that it’s an urgent and serious problem to do something — which I would expect.

When it comes to pessimism versus optimism, what you sometimes find is sometimes they’ve based studies around showing people scary films of really pessimistic climate dooms kind of endings. What they seem to find is that if you show someone a really doomsday movie, initially, they’re like, “Oh gosh, we need to do something about this. This is terrible. This is where we could be heading.” But often that really dies out very quickly. They kind of revert back to normal. I don’t know if you saw the film Don’t Look Up, which had so much hype at the time, and everyone was like, “Oh, this is so alarming,” and kind of drifted back. I don’t really hear about it anymore.

What they find is that you want to show this pessimistic, like “this is where we could be heading” thing, and what seems to be better for sustainable action is you need to combine it with “this is what we can actually do about it.” So you need to give people actionable stuff to go along with the doomsday stuff. Which again, I think comes back how I think you can view the problem and the solution quite differently: you can be concerned about the problem, but also optimistic about the solutions to address it.

Luisa Rodriguez: That just makes tonnes of sense when I reflect on my own experience, which is just a bit more of the same anecdotal evidence.

Psychological challenges with this kind of work [02:14:40]

Luisa Rodriguez: Is there anything else that feels particularly hard about your work?

Hannah Ritchie: I feel this personally, but I think it’s also something that I’m sure affects other people at Our World in Data. especially in recent years: the platform has grown a lot in recent years. In large part to do with COVID, because we became the COVID data people. We had a large audience before that, but I think it’s just shifted a lot. And now there’s just this really intense pressure to get things right — people take our work very seriously. Often, they’ll frame it as like, “I look at Our World in Data and I take as gospel what I see on the website, and I just assume that’s true.”

Luisa Rodriguez: I have the same worries at 80,000 Hours. But yeah, go on.

Hannah Ritchie: Which is a very high bar. And obviously, we do a tonne to make sure that we are getting everything right, but there is a lot of pressure there, and concern that one error could have pretty bad consequences — either in terms of a decision that’s made or just reputationally. Like, I think at Our World in Data, we always feel like we’re just one mistake away from our reputation being bashed.

Luisa Rodriguez: Wow. Yeah. That sounds really anxiety-inducing. It’s like you’re doing a bunch of excellent work, but it could just be one or a few mistakes that make it all, I guess, reputationally tarnished.

Hannah Ritchie: Yeah. Exactly. And on a personal level, part of what’s difficult is we cover so many different topics; it’s really broad, the topics that we cover. But I also straddle a lot of disciplines in some sense. Like, we’re researchers, we’re data analysts, we’re writers, we do data viz.

So in some sense, I feel often a little bit of imposter syndrome, because I never quite feel like I’m expertly skilled in this discipline, or I’m the expert on this topic. So I’m sure if I went into any of the academic fields that I write about and research, if I went into a really nerdy climate conference, I would definitely feel imposter syndrome — because there’s no way I’m any of the experts in the room. In the same way that if I went with a group of journalists, I’m not an expert writer; I’m like an OK writer that can write about research and data viz and stuff. So I think there’s this imposter syndrome that comes from straddling so many different things at once.

Luisa Rodriguez: Yeah. I’ve totally found that with work that feels kind of generalist-y — where you try to be good at many things, but then you’re never exceptionally good at a single thing — so when you’re in a space about that thing, you feel like you don’t know as much as other people. And you in fact probably don’t.

And I find that it feels especially common in spaces where people are really focused on actually making an impact on the world. Because to do that, you tend to need to be very interdisciplinary: you need to look at a problem from lots of different angles and not do the kind of standard academic thing of looking at a really narrow thing that you can solve with your own single discipline. To solve problems like agricultural productivity and poverty in sub-Saharan Africa, you must need to think about like 10 different disciplines, and then I can totally imagine how you’d then just feel like you don’t know enough about any one of them.

Hannah Ritchie: Definitely. That’s definitely the feeling, where in that sense, in the back of my head, I’m like, the agricultural economist is not going to agree with what I say; probably the soil scientists are not going to agree with what I say; the agrotech company is not going to agree. So when you straddle so many different disciplines, it almost feels like none of the experts are really going to agree with what you’re saying, because you’re trying to mix them up and come up with a true — but in some sense, simplified — narrative that people can understand.

Luisa Rodriguez: Yeah. That sounds really hard. And I guess the flip side is none of those experts can come up with a full multidisciplinary, multidimensional solution. Like, the soil expert will have advice on soil, but they won’t be able to look at the problem as a whole and think about what all the possible solutions are, and point to some of the best ones. Which feels like a huge limitation, but I guess it sounds like your brain is — understandably, and mine would too — focusing on the ways that you’re not as expert as them, even though you might be able to offer more insights into big problems.

Have you made any progress on feeling less impostery? Has anything helped?

Hannah Ritchie: I think the way I respond to it sometimes differs a bit. I think to some extent, the imposter syndrome has benefited me professionally. Like, my imposter syndrome often leads to anxiety, as I said, about getting stuff right that often seems very high stakes. And I think professionally, it’s just very good if I’m really paranoid about getting stuff right.

Luisa Rodriguez: Right. If you’re meticulous and perfectionist.

Hannah Ritchie: To that extent, it’s benefited me professionally, even if personally it has quite a high toll on how I feel.

Luisa Rodriguez: That’s interesting. In my own struggle with imposter syndrome, I’ve found overall it’s hindered my ability to do good work more than it’s helped. But I guess in some types of roles, that type of anxiety — where you’re worried about making a mistake, if mistakes really are just extremely, extremely bad — can be helpful.

Hannah Ritchie: Yeah. I think there’s two sides. So I think overall, it’s been a benefit. And I read your essay on imposter syndrome, and I loved it. I think there’s some cases where my reaction was similar to yours, where I would opt out of doing stuff.

A key example here is interviews. So I do a lot of interviews, often with news media, because they want to get the facts straight for their articles, which is great. Or on the radio. And I do a lot of them, but I often also turn down a lot of them. Some of them I turned down because I just can’t possibly do them all, but some of them I turn down because I either feel like I’m not the expert that they should be speaking to about that — which is sometimes right, but sometimes I think it’s not right, and I could very easily answer the questions. So I either reject it because I feel like I’m not expert enough, or also because I just know that… To them, it seems like I’m giving them 10 minutes of my time to give them the answer, but because I’m so paranoid about getting the stuff right, I probably check it then five times, and then I come back to it later to check it. And then I probably have a sleepless night in case I gave them the wrong number and they put it on the radio. So sometimes I just say no because I’m like, I actually want to sleep tonight.

So I think from that perspective, it’s definitely hindered. One, because I probably could have given them a good answer and I didn’t, and I guess that goes against my values because I often advocate that news media should be really meticulous about trying to get the facts right and speaking to experts — and then when they ask me, I say no, which is not aligned. And then also because often it just takes quite a personal toll.

Luisa Rodriguez: Yeah. That sounds terrible. And I know the feeling of the sleepless night, when you’re worried you’ve made a mistake, or might make a mistake, on some fact you’ve been asked about. And it sucks. It really sucks. So yeah, I’m really sorry to hear. You said that you feel like you’ve kind of made some progress on it. Is there a single thing that you feel like has helped most?

Hannah Ritchie: Yeah. I think it’s definitely gotten a lot better. I’ve actually done therapy, and it was one of the big parts of therapy. And I think there’s a couple of things we worked through, which I’ve found helpful. One is, I actually think it’s to some extent the opposite from you, because I think it was one of the things you said was really a hindrance for you, the catastrophising thing.

Luisa Rodriguez: Right. Yeah. Imagining the worst thing that could possibly happen.

Hannah Ritchie: Yeah. Where I actually find it quite useful sometimes to do that, and to work through, like, “OK, I get the number wrong. I go on the radio and I say the wrong number. What’s the worst thing that could happen?” Like, someone points out that I got the number wrong. I have to apologise to the BBC because I got the number wrong. They’re understanding, because people get numbers wrong — even the best people get the numbers wrong. And I can’t do that all the time, and I probably have a limited number of lives on that, but if I do that once, it’s fine, and it’s not the end of the world.

Luisa Rodriguez: Yeah. That makes tonnes of sense. And yeah, there’s a thing that I do, I catastrophise. But I think you’re almost pointing at a slightly different thing, which I’ve also been encouraged to do in therapy. My therapist calls it “negative visualisation” — kind of really engaging with those worst-case outcomes. Because the thing that I do is catastrophise and then be like, “…and therefore, I can’t do it.” Like, if I do some interview and it goes horribly, that would be unbearable. I’m just going to say no.

But then, yeah, I totally buy and have sometimes experimented with actually thinking about the worst case. And in fact, it’s probably better than the catastrophising thing I was doing, because the catastrophising thing might actually have been even worse than the worst case — it’s like, “If I do that interview and it goes badly, everyone will think I’m an idiot, and my partner will stop loving me,” just like ridiculous things.

And so imagining the actual worst case, it sounds like for you, and hopefully for others, can be a really healthy exercise: “Actually, realistically, the worst case isn’t quite as bad. Here’s what would happen. I can take steps to manage the really bad cases, but even if things go wrong, mostly things are going to be OK.” And if they’re not, then you say no, and maybe that’s reasonable. But if they are, then maybe you get over the hump of constantly turning things down because you can tolerate the realistic worst-case outcome a bit better.

Hannah Ritchie: Yeah. Exactly. And I think there, another big thing has just been building an evidence base for the fact that I’ve done all this stuff, it hasn’t gone wrong, and it’s going fine. Like, “I am careful with the numbers. I’m not going to just pluck one out of thin air. I know that I’m careful, and I try to base everything on the research, and I have evidence of doing these perfectly fine.” So often I should just draw on that and trust myself that this time I’m also going to do fine.

Luisa Rodriguez: Totally. That exercise of being able to recall all the times that you did the things, and they went fine, seems huge. I wonder how much you had to do that while you were writing your book? Because I imagine, to write a book and put a bunch of these facts in print must feel super anxiety-inducing, because it’s less editable than the OWID website, and probably lots of people are going to review and critique it. Did you feel a bunch of anxiety about that, about getting things right in the book?

Hannah Ritchie: I mean, yeah, that’s always been there. Probably less so when I was writing it, because I was just enjoying writing it. One thing that’s benefited it is that a lot of the stuff, as I said, has been based on research I’ve done at Our World in Data over the past seven years. So a lot of it has already been out there in the public for a long time, and if there were errors or really strong counterarguments, I feel like I would have got a lot of them by now just based on the number of eyes that are on it.

But it’s not even that the book’s on one topic — I literally cover every single environmental topic — and I’m sure there’s going to be fishing experts that do not like the chapter on fishing, or plastic experts that don’t like the chapter on plastic. This is one of the many great things about OWID: we now have amazing opportunities to reach the world’s experts.

Luisa Rodriguez: Yeah. That’s really cool.

Hannah Ritchie: So each of the individual chapters has been reviewed by experts in that specific field. But I’m sure there’s so many numbers in there that people will have issues with some of them.

Luisa Rodriguez: Yeah. I don’t know if you’ve thought at all about how to prepare emotionally for people finding errors, if they are there?

Hannah Ritchie: I mean, there’s also a difference between an error and a difference of opinion.

Luisa Rodriguez: Or interpretation of the facts.

Hannah Ritchie: I mean, errors: if there are errors, then they will be corrected. If there’s differences of opinion, to some extent, it’s good, because I’m generating discussion and I will look at it. And I’m always very willing to change my mind if I see convincing arguments. But also, just because our work on OWID is so public, I’m kind of used to the backlash by now.

Luisa Rodriguez: Oh, really? So some exposure therapy has already worked for you.

Hannah Ritchie: Exactly.

Luisa Rodriguez: Well, I’m glad it sounds like that isn’t causing you as much anxiety, which feels really hopeful to me. I mean, you’ve written a book. You’ve given a TED Talk. So it sounds like you’ve made enough progress to be able to still do really ambitious things, not have your anxiety be horribly painful. And I think that’s just great, given that it sounds like we’ve struggled with some of the same feelings. Thank you for sharing.

Hannah Ritchie: Yeah. No problem.

Mistakes Hannah’s learned from [02:29:49]

Luisa Rodriguez: Cool. Well, I have taken loads of your time now, but we’ve got time for one final question: What’s one of the most valuable mistakes you’ve ever made? And how can our listeners learn from it?

Hannah Ritchie: I think I’ve got two. One is a really insignificant one, but I learned it the hard way. So the first one is, when I was doing my TED Talk, I had my little outfit planned. I had my little blouse. I had it all ironed the night before. It was hanging up ready because I have this first on the next morning. So I was all prepared. For once I ironed my shirt. And then I turned up to the centre and I was quite nervous, so I was having a little sit on the sofa. I stood up and it was just a bundle of creases. Totally creased. And I was thinking, “Oh, no. I’m going to go on the TED stage. My mom’s going to see the talk and all she’s going to say is, ‘Did you not iron your shirt?'” And the thing is, I’d ironed my shirt for once!

So I was panicking. “What am I going to do with this shirt?” I was considering running across back to my hotel to iron it. The TED people were like, “Absolutely not. You cannot leave from here now, you’re on soon.” Actually, the staff at TED are amazing. It’s very clear that they want to support you to be able to give the absolute best talk you can. So a backstage man at TED, I gave him my shirt, and he went away and ironed it for me. And if anyone watches the TED Talk, you’ll see it’s completely crisp.

Luisa Rodriguez: That’s amazing.

Hannah Ritchie: So what listeners can learn from it is: If you’re giving a talk, you must remain standing before you do it the whole time.

Luisa Rodriguez: Excellent tip. Very practical.

Hannah Ritchie: And then the second one is more of a general one, and I think it’s less of a mistake I’ve made. But in terms of advice, I think a lot of people would have advised me against a lot of the trajectories I’ve gone on, where I’m sure they would have said, “I think that’s a mistake.” And I think this comes back a little bit to being this generalist.

Luisa Rodriguez: So is an example something like working at OWID, which is not obviously an academic institution, despite having a PhD? Is that the kind of thing?

Hannah Ritchie: Yeah. So a really clear example is that I was very clearly told by many people, “If you want to do research, you have to stay in academia.” And OWID is academic-tangential, but it’s not, like, core; we don’t write original academic papers. And I’ve been told many times, “If you want to progress in academia, you have to write papers.” And kind of my point is that I don’t really want to progress in academia.

So I think one of the lessons I’ve learned is to be quite selective about who I take advice from. I think if you’re going to go down a traditional pathway, there’s loads of great advice out there, and people can give you amazing advice, especially if they’ve climbed the ranks in that field. I think if you’re kind of straddling many different ones, you need to be a bit more careful, because it’s such a non-trodden path, and people often can’t see outside their traditional pathway that they followed. So I think, for me, because I have become more of a generalist, it’s actually served me well to ignore some of the pieces of advice I’ve had in the past.

Luisa Rodriguez: Right. Yeah, I would guess it’s true of at least some of our listeners, who are trying to have impacts with their career, often the problems they’re trying to address are neglected, and the solutions they’re interested in are also neglected. And probably it involves, for some of them, some amount of nontraditional path-taking. That definitely feels true of me. And it sounds like it’s really probably easy to get advice from people who’ve gone the traditional path, and then be like, “Oh, no. Am I doing the wrong thing? I’m supposed to stay in academia.” And it sounds like you’re saying, for you, it’s been really important to… Would you say it was like taking advice from people who share more of your values, or who understand your goals better?

Hannah Ritchie: I think that there’s a fine line. My advice is not to ignore all advice. I think there you can very easily fall into a trap of, “No one understands what I’m trying to do, so I need to pave my completely new path on my own.” I don’t think that’s the case. There are people that can give you really good advice, but I think you need to just be a bit more selective, and you need to find people that can maybe think slightly beyond the conventional. And also have people that you really trust, that really want to give you advice in your best interests — not about, I don’t know, trying to serve an academic institution, for example.

Luisa Rodriguez: Yeah, that makes a lot of sense. Cool. That’s all the time we have for today. It’s been such a pleasure. Thanks so much for coming on the show, Hannah.

Hannah Ritchie: Thank you. I’ve loved it.

Rob’s outro [02:35:22]

Rob Wiblin: Do you regularly watch video interviews on YouTube? We are trying to understand how many people would rather watch this show rather than listen to it. So if you would watch videos of our interviews — and, indeed, already watch similar things on YouTube — drop us an email to [email protected], because we’d love to chat with you about it.

Keep in mind that as of recently, we offer shorter highlights versions of our episodes over on 80k After Hours if you’d like to sample from interviews before deciding whether to commit to listen to the whole thing.

All right, The 80,000 Hours Podcast is produced and edited by Keiran Harris.

The audio engineering team is led by Ben Cordell, with mastering and technical editing for this episode by Milo McGuire and Dominic Armstrong.

Additional content editing by Luisa Rodriguez and Katy Moore, who also puts together full transcripts and an extensive collection of links to learn more — those are available on our site.

Thanks for joining, talk to you again soon.