Last month, I participated in a thought-provoking fireside chat at Chatham House in London. The moderator was Hannah Ritchie, the lead researcher at Our World in Data, whose thinking on the environment has influenced my own (and whose forthcoming book, Not the End of the World, I’ve read and loved). Over the course of our conversation, we talked about two of the issues I’m most passionate about—climate change and global development—and why they both demand urgent action or “impatient optimism.” After all, it’s not enough to keep the planet livable. We also need to make it a better place to live, a place where everyone has an equal chance to survive and thrive no matter where they’re born. And we’ll only accomplish that if we believe progress is possible and continue to pursue it.

You can read the full transcript of our conversation here:

HANNAH RITCHIE: Welcome Bill Gates. I’m really excited to have this conversation. We’re going to dig into some of the specifics of climate, but I wanted to start with a little bit of the backstory on how you got into climate. Your foundation works on some of the world’s largest problems, from polio and malaria to childhood mortality and maternal mortality, and agriculture. The world has many problems, and that’s a prioritization exercise. If you’re putting money here, you can’t put as much money there. Why did you then come to the decision that you have to put a significant amount of money into climate change?

BILL GATES: At the Gates Foundation, about 70% of what we do is global health. That has been a phenomenal journey, and far more successful than we thought when we set out. When we got started in the year 2000, over 10 million children under five were dying every year. Now that has been cut in half. The primary reason for that is that vaccines were invented, which the Foundation played the central role there, and they were financed through Gavi, so they were getting out to all the world’s children. Vaccines for respiratory disease, diarrheal disease, and things like bed nets, through The Global Fund, to cut malaria deaths.

In Africa, most people in sub-Saharan Africa are smallholder farmers. Sadly, their crop productivity is extremely low. They face a lot of population growth, and the headwinds of climate are at their worst in the tropical zones. If you’re near to the equator, that is where the absolute temperatures are going to make it difficult, both for humans and for the food that they grow. With climate change comes more droughts and more floods, more extreme weather, because more heat is more energy.

The idea of, okay, what are we doing? What is the equivalent of the Green Revolution from the 1970s, where new seeds were created that avoided what was a predicted mass starvation? Are we coming up with those seeds that are going to be climate resilient, and have the productivity to let Africa not only feed itself, but become a net food exporter?

I got educated starting in the year 2000, when I had some climate scientists who would do a lot of sessions with me every year. I started a nuclear energy company in 2008 to do fission, and then at the Paris 2015 talks, I came up with Breakthrough Energy. A lot of Breakthrough Energy is not philanthropic capital. There is for the policy work, and I’ve spent hundreds of millions on climate philanthropy grants related to climate, but the Foundation is $8 billion a year on global health.

We are saving lives for less than a few thousand dollars per life saved. I believe that we can use mostly market mechanisms to do the mitigation task. The Gates Foundation does the adaptation and Breakthrough Energy does the mitigation.

HANNAH RITCHIE: There is this focus on human welfare, and then seeing that there are problems there, and then climate change has the potential to compound them and make them worse.

BILL GATES: Exactly. It’s all through the lens of the human condition and inequity. It is the paradox that people don’t realize how much progress we have made. And yet, if they go to those countries and see, okay, we still have 5 million children dying every year, and in parts of sub-Saharan Africa like Northern Nigeria, 20% of kids die before their fifth birthday, whereas in rich countries, that number is less than 1%.

It is stunning that not much money is spent on malaria. When we did our first $30 million grant, we became the largest funders of the disease that was killing a million children every single year. Now that number is down to 400,000. We have a path, though we don’t know how long it will take to get to eradication.

The human condition is far more inequitable than people know. And yet, the absolute progress has been phenomenal.

HANNAH RITCHIE: You talked a little bit about a lot of threats, with one of them being the potential on agriculture, particularly within equatorial regions. What do you see as the biggest threats of climate change?

BILL GATES: In temperate zone countries, you are going to have sea level rise, you will have more forest fires, and you will have to switch your seed somewhat. But there are people who don’t have air conditioning who will get air conditioning. The effects are not as dramatic in the temperate zone, where people are well off and not doing outdoor farming.

In Africa, if your crop fails, your children aren’t going to get enough food and so you get malnutrition. Kids who have malnutrition, it is incredibly tragic. They are four times more likely to die of pneumonia, diarrhea, malaria, and even if they survive, their physical and mental development is far short of what it should be. Their ability, individually or for their country, to get educated and contribute has been largely eliminated because of those malnutrition problems.

To the degree that climate feeds malnutrition problems or causes forced migration, then the human condition can be very bad, mostly in these tropical zones.

HANNAH RITCHIE: Changing it up a little bit, on optimism. This year, we’ve seen record breaking heatwaves, we’ve seen it is possible we may cross 1.5 degrees this year, which does not mean we’ve broken the Paris Agreement, but it’s a little bit of a frightening warning. If you go back a decade, are you more or less optimistic about where we are on climate change now, or then?

BILL GATES: I’m certainly more optimistic because in 2015, when the Paris Agreement was signed, there were so many areas of emission where there wasn’t any activity. For example, the industrial area, which for most countries is the largest single area. That includes things like steel and cement. There weren’t brilliant people saying, "Gosh, let’s rethink how we do steel.” It has been a long time since there has been a basic change there, or rethinking how we do cement.

As part of that 2015 event, President Obama and I, and President Hollande, and Prime Minister Modi did an event called Mission Innovation that said, "Hey, we need to do more R&D, we need to have more venture capital, we need to come up with more solutions." It was a leap of faith whether there would be ideas, and so I raised a billion dollars very quickly from individuals for the first Breakthrough Energy Venture fund. We said we will only invest in things that can get rid of a half-percent of global emissions. It is an extreme single-purpose venture activity.

Now we have raised over $3 billion, we have over 100 companies, and I have to say, instead of not being able to find good ideas, we have found so many good ideas. We have multiple approaches in each of the areas. In steel, we have four different approaches, and in cement, we have four different approaches, like carbon capture, quite a few approaches.

Although a lot of these are still lab-level results, and the path to get from the lab level to pilot plants, and then try to scale those things up and get the extra costs, or what I call the green premium down, is still going to be super-hard, as to how we get rich countries, rich companies, rich individuals to help us get to the magic point where the green approach doesn’t cost any more, or the green premium of zero. But what I’ve seen is way more than sitting there in 2015, announcing Breakthrough Energy, as to what I expected to see.

HANNAH RITCHIE: I feel the same, but against the common narrative, I would say I feel more optimistic than I did a decade ago. I think the area you are mostly talking about, those hard-to-abate sectors, steel, cement, et cetera, even if you look at the relatively easy sectors to beat—electricity for example—if you go back a decade, solar and wind were the most expensive energy sources we had. Since then, the price of solar has dropped 90%, and the price of wind has dropped 70%, and electric vehicles are now economically viable. When I was sitting in 2015, I could not foresee a future where any of these would be economically viable, not only for rich countries, but for middle- or low-income countries.

BILL GATES: Yes, the two areas where we have made the most progress on getting green premiums down is parts of electricity generation and the high end of the automotive market. We still have a lot of work to do for the low end of the automotive market, particularly for somebody who doesn’t have a garage where they could charge their car at night. The electricity challenge is still a bit daunting because when you have weather dependent sources, if you have things like a cold snap, and you are relying on electricity to heat buildings, then did you have large energy storage? Or do you have baseload things like fission or fusion that are able to come in with that load that you can’t delay? You can’t say, "Okay, I’ll warm your home a couple days from now," but you have to do it right as the cold snap sinks in.

We haven’t solved electricity, but we can see that the pieces are coming together, particularly if we get better forms of fusion or fission that could come in and play that complementary baseload picture.

The miracle of lithium-ion batteries, the miracle of solar panels, that’s the kind of thing we need to duplicate in all of the areas of emissions. As you say, I organized an extra panel on solar panels in 2015 and had them project how far would it go down, and it has gone down further than even the most optimistic of those people thought it would. These learning curve innovations often can surprise us on the positive side.

HANNAH RITCHIE: On deployment, if you look at any of the forecasts for deployment of solar, even the most optimistic ones are really long.

BILL GATES: Yes, but in a lot of countries, we are now running into, though it varies by country, the willingness to permit wind, or solar in your backyard, and then because those are often far away from where the electricity is needed, there is the challenge in the permitting of the transmission. To build this green grid, which will have to provide probably two-and-a-half times as much electricity as we use today, there are still some obstacles. The rate of installation has to continue to go up. Yet we’re seeing, like offshore wind, where the bid process did not go forward, but I think that will get fixed in some way, and there is onshore permitting and transmission, and so we really have to plan on this mix of policy and innovation to get rid of those bottlenecks.

HANNAH RITCHIE: On optimism, I often try to promote the message of optimism, not that this stuff will just happen on its own, but that we have the ability to solve these problems. These problems are solvable, and we are making progress. I expect you probably do the same. How do you balance trying to promote an optimistic message without sounding like you’re underplaying the issue?

BILL GATES: That’s a real challenge. How do you promote the problem without over-depressing people? You can err on the negative side, like just showing pictures of kids dying of malaria, and people are like, "Okay, I’m not going to Africa. I don’t want to hear about this again."

Even in climate, some people are despairing because they see that we’re falling short in a lot of ways. It’s a huge collective action problem in terms of every country, every area of emissions to try and get all the way to zero. It’s striking that balance, and I think in your recent TED Talk, you did a good job of that. Hans Rosling, I think we both think of as someone who has inspired us, where he was much more in the health domain, but I still consider his TED Talk one of the most profound TED Talks ever given, because it was both about the need to do more, but a sense of hope for the incredible progress of what we’ve done on health.

HANNAH RITCHIE: Before I spoke with Hans Rosling I was very pessimistic. He has had a profound impact. I think one nice framing that I like is my colleague Max Roser has this Venn diagram that shows the fact that you can hold three thoughts at the same time.

One, the world is awful, one the world is much better, and the third one being the world can be much better. If you even take the simple example of child mortality, the world is awful and 5 million children die every year, which is completely unacceptable, because most of those deaths are preventable. But a few decades ago, you had 12 million dying, so the world is better than it was. By looking at that perspective, you can see it is actually possible that we can then make things better in the future.

I think you can even relate that to climate, where we’re currently on track for around 2.5 degrees, which is completely unacceptable, and we need to bring that down, and so the world is still awful. But a decade ago, we were on track for 3 to 4 degrees, and so we are getting there. We are getting there too slowly, but we can see by looking backwards at progress that we can continue to move things forward.

BILL GATES: Yes, these positive datapoints are amazing. For instance, in your book, which is coming out in January, and I was lucky enough to get an early copy, you talked about how emissions in the UK, per person, are actually down quite dramatically, because it was really coal driven, but now it is essentially not at all. That’s fantastic. There’s still a fair bit of natural gas, and so it’s not completely green, but it’s a sign of what can be done, just like the childhood death number.

When I showed climate activists that we’ve gone from 10 million to 5 million they were like, "No? What? Why didn’t somebody tell us that?" It’s sort of this report card for humanity, that we should say, "Wow, what did we do right?" How did we build Gavi? The UK contributed to Gavi, and the whole world came together to do something incredible.

We set a goal of getting from 5 million to 2.5 million by 2030, and because of the Ukrainian war, interest rates, and the African debt, we will miss that – it will be sometime between 2035 and 2040 when we get that second halving of childhood deaths, all the way down to 2.5 million.

HANNAH RITCHIE: Right, I think there’s a difference between what I might call complacent optimism or stupid optimism, where you look at the trendline going down and say, "Yeah, we’ll just continue," but you know what? It won’t continue; you have to push it. I think we would frame that as impatient optimism that, yes, there’s been this progress, but how do we drive more of it?

BILL GATES: Yes, I just came from Senegal, where the Foundation had its annual science meeting, and I was just so inspired by the scientists. We have new ideas to dramatically reduce maternal mortality and new ideas, particularly within the first 30 days of life, where over half of those deaths in the first five years were actually in the first 30 days. We have had vaccines for the rest of that time which have been miraculous, but we now have very cheap, miraculous interventions for that first 30 days. This will let us make the next stage of progress, but it is by funding those scientists, and then figuring out how do you scale this stuff up, even in tough places, so that we can get the end result.

HANNAH RITCHIE: Bringing it back to climate, I know you get excited about innovation. What are some of the areas that you’re most excited about for innovation? Where do you think the gaps are, where we are not making progress?

BILL GATES: Across this portfolio of 100 companies it’s hard to pick my favorite. Some are kind of straightforward, like a company that makes windows where the temperature doesn’t cross over, but instead, it blocks getting cold in the winter or hot in the summer, which is very cheap. Or there is a company where you leave your home, and you pump this air through, but it’s got a chemical in it. When it sees cracks, it actually seals those cracks. You don’t have to find the cracks; you just pump the air in.

You can reduce the amount of heat loss between the windows and getting rid of those cracks. You can reduce the energy bill by a factor of two, which then means less load on the overall energy system. That one is not high tech. It’s not like TerraPower fission, or Commonwealth Fusion Tokamak design, which there are still some risks in that.

In areas like industrial heat, today when you want to do an industrial process, which people don’t visit very often, but you burn natural gas, and you get this very high temperature. We have shown with several companies in the portfolio that by using solar panels, and just heating a very cheap, brick-like substance, you can actually get industrial heat cheaper than burning natural gas without any government consideration of the CO2 that natural gas puts out.

Those companies are really scaling up because it works. It’s economic, it doesn’t require that much of a policy. You get wins in some of those areas that can move out fairly quickly. The cement and steel ones are the ones, in a way, I’m most impressed by, because I wasn’t sure we’d find anything in those spaces.

HANNAH RITCHIE: To explain the cement thing, around half of emissions from cement just come from the energy used to produce it. You could decarbonize that. The problem, I guess, with cement is that you are taking basically limestone, and then you are converting it to calcium oxide. But the byproduct you get in that conversion process is CO2. Basically, you need a way to capture that CO2.

BILL GATES: Yes. Limestone is calcium carbonate, and you use natural gas, which by burning that creates CO2. As you heat the limestone, that releases CO2. It’s exactly as you say, it’s an equal number amount of emissions.

One of our companies doesn’t use limestone. They actually go and find another source of calcium, which fortunately turns out to be quite abundant and cheap. They make exactly the same cement that we make today, but not using limestone as the input. I was stunned that you could do that.

We have other companies that make things that are slightly different than Portland cement, that they think is good for many applications, but getting the certification of the building codes and everything, of course, people are very conservative about. Okay, how good is it going to be 20 years from now, when cars are crossing this bridge? Will it work well?

One company took a risk on the mineral source, another company took the risk on the certification process. They’re rolling out and seeing which geographies the different approaches get adopted in.

HANNAH RITCHIE: You mentioned a few times the green premium. For those that maybe don’t know what that is, do you want to briefly explain what the green premium means?

BILL GATES: There’s the current way of making things, and then there is a new way of making them that has no emissions. You could say the brute force way is to say, okay, I’ll still make it the old way, but I’ll pay for some direct air capture person to pull those things out of the air. For something like cement, that would mean that cement would be twice as expensive.

When you say to India, please do that, make your cement twice as expensive, they’re like, hey, we have emitted nothing, compared to you, on a per capita basis. We’re still providing basic shelter, and you’re building things that are more than you need. Only if you subsidize us will that work.

The idea is, you want to go back and rethink the whole cement process, either how you capture that CO2 before it gets emitted. Electric cars are a really good example. It’s a rethink of how you propel the car. Now, it requires you to also take your electricity system and get that to zero, but you’re going to need to do that anyway. It means the size of the electricity system, just for the cars alone, cars and buses, your electricity system has to be about 40% larger than it is today. You have to make it green.

Whenever people say we have a certain percentage of renewables, essentially 200% renewables up from 15%. It is ambitious, but we measure in every area, what is the current green premium?

Some of you may have tried Impossible Burgers or Beyond Meat. That beef, you can think of the green premium as two things. It, today, has a cost premium, and it doesn’t taste quite as good – it’s close – as the real thing. Those companies have a challenge. Now, people who care about climate, it’s great, they are willing to create that bootstrap market. But the big win is if they get the cost below normal beef, and they get the taste so you truly can’t tell. I’m quite optimistic that a whole set of companies are headed towards achieving that over the next five to 10 years.

HANNAH RITCHIE: You read my mind, because this morning, I put out an article saying that meat substitutes are too expensive. [Laughter]

BILL GATES: No, they are definitely too expensive. They are around 50% more expensive. I think it is more that they haven’t matched the taste. They’ve got to change both of those in order to be mainstream. Today, only a few percent of beef is made without a cow. [Laughter]

HANNAH RITCHIE: In the last decade, we have seen dramatic improvements in solar and wind. We have seen the costs plummet, and we have seen them take off at pretty rapid rates. At the same time, nuclear has come up against opposition, especially in Western countries. What role do you see nuclear playing in the future energy system?

BILL GATES: Well, unfortunately, there’s enough challenges with both nuclear fission and fusion that we can’t depend on it. It would be extremely helpful if nuclear fission came up with a product that was both economic, and the provable safety was even better than we have in nuclear today. The nuclear industry basically failed, because their product was too expensive. It wasn’t because of the waste or safety-type issues, which we can get into those, but it was economics.

First and foremost, you must have a much different economic proposition. The nuclear reactor I’m involved in, TerraPower, we only generate electricity when the renewable sources that have very little marginal costs aren’t generating. We just make heat all day, and then only when the bid price of electricity is high enough, do we actually generate electricity, because otherwise, you have all this capital cost that half the time, the solar bid into that market is going to be very low.

I think fission, we shouldn’t give up on it. I’m involved in that company only because it may be able to make a significant contribution to climate change. There are about 16 fusion companies. They have more challenges. Fission, we understand the science. It is all just engineering and cost. In fusion, there’s even some science of how these plasmas create forces that we are working on. Of the sixteen, Breakthrough Energy is invested in four of them, which are four very different approaches.

I think it’s just a question of when will fusion come along? A cynic might say, okay, it’s always been 40 to 50 years, but the amount of brilliant people working on it is, today approximately 20 times higher than it was 10 years ago. It’s such a variety of approaches, I do think that will come along. But again, we’re not to the point where you can buy one of these things, or even make it part of your plan.

HANNAH RITCHIE: We should invest some money in it, and hope that it comes through, but we need to get moving on the rest of the stuff at the same time.

BILL GATES: That’s right. Certainly, every solar panel we put in, every wind thing we put in is a step forward, because we are going to have this hybrid system that will either be wind plus solar plus a lot of storage, or wind plus solar plus storage, and fission and/or fusion.

I can’t overstate how much easier it is to solve the problem if you can mix in some degree of fission or fusion that are there to fill in the periods where renewables are not generating. Cold snaps or where you have these cold fronts just sitting there, that’s when houses need the most heating. That’s when neither wind nor solar are generating. Now, if your transmission grid is big enough, maybe somewhere else, there isn’t the cold front, but building those massive transmission grids, we have to accelerate our work on that as well.

HANNAH RITCHIE: I guess the solar and wind are incredibly cheap. But I can see that once you start getting to the very, very top, that can start to become very expensive. Squeezing out the last 10% or 20% on your total grid could be very expensive.

BILL GATES: Yes, and all people buy is reliability. They don’t buy electricity. If you say, okay, every once in a while, we have super cheap electricity, there is no bid for that. The bid is 24-hour guaranteed, particularly during heat waves and cold snaps. Breakthrough Energy, its science group is doing a ton of these open source grid models, so people can try out in the face of more extreme weather, okay, how reliable will their grid be?

HANNAH RITCHIE: Climate change is a global problem. It needs international collaboration. But one thing I don’t necessarily agree with is it is often framed as this homogenous, global story, where in fact, to me, there are very different stories for climate change, depending on where you are in the world. The high-income countries’ story is very different from the middle-income is very different from the low-income.

First of all, do you agree with that? How would you frame the differences between those income levels?

BILL GATES: Absolutely. The high-income countries have to lead the way. We have the greatest historical emissions, and we have the most risk capital and ability to innovate on these new technologies. We not only owe it to the world to get to zero, we also owe it to them to play the primary role in driving green premiums to zero.

Middle-income countries, where you have China as the richest middle-income, India’s the least, and Indonesia, Brazil, Vietnam, almost 70% of all people live in those countries, which is a miracle, because that wasn’t true 50 years ago. They need to reach out and help with the adoption, because since they’re responsible for so much of the emissions, that’s where this thing is going to be won or lost, is how easy we’ve made it for them to go for adoption.

The low-income countries, they’re about 4% of emissions. In a sense, they should generate electricity however it is cheapest for them to do, because it is kind of a rounding error. The equities would say that we shouldn’t burden them with this problem, in terms of their energy generation, even though the vast majority of the suffering from climate will be low-income countries.

HANNAH RITCHIE: Right, you were talking about sub-Saharan Africa earlier, and I think cumulatively, the continent as a whole has contributed around 1% of the total emissions. On that note, a question I get asked a lot, because we’re in the UK, is the UK only emits around 1% of the emissions today. Why should we care? Why should we care about reducing our emissions? What role should the UK play in climate change if it only contributes 1%?

BILL GATES: Well, this is a collective action problem. There will be countries, like maybe Russia, that bringing them into this collective action might be difficult. If you really want to get to true zero, you might have to use direct air capture to cancel out the most recalcitrant, and maybe the low-income emissions as well. That’s where it might play a role.

Overall, the Paris Agreement was a milestone. It’s not an enforceable thing. Even the U.S. would not have adopted it. In fact, we de-adopted it for four years and then re-adopted it. [Laughter]

This will never get solved if the rich countries take that type of approach of, okay, we’re not that big a piece of the problem.

The UK has done a lot of things very well. I have on my phone where I can look for all the countries and see, okay, the electricity they’re generating, exactly how much carbon is coming out of the different systems. It’s come a long way, and the overall global footprint for electricity generation has come a long way.

HANNAH RITCHIE: Yes, the way I like to frame it as if you look at the breakdown on global emissions, China is responsible for around a third. Then you’ve got another third, which is countries that emit more than 2% each. They might say, oh, we’re relatively big emitters. But then the last third are all countries that emit less than 2% each. They are what they would frame as small emitters. If they all step back and say, we’re not going to do anything, then you’re missing a part of the emissions. No one would say China doesn’t matter, their emissions don’t matter. You can’t do that collectively for that last word.

In the climate space, the focus is on emissions reduction. Now, there are a few things that people would say can come across as a way to get out of reducing emissions or a moral hazard for not taking this seriously enough. One of them is carbon removal, and the other one is adaptation. How do you think about the balance of those within the total mix of addressing climate change?

BILL GATES: Adaptation covers a broad range of things. In rich countries, that means you have to look at forest fire risk and see, okay, exactly where it might happen? Do you have the appropriate barriers? You have to think about sea level rise and where are you insuring homes, and where do you actually have to make changes? There are very complex engineering projects that sometimes will make sense, sometimes they won’t.

To me, adaptation is the strongest case, that it is a moral argument that you are going to take all this progress in human development, and reverse a lot of it, if you don’t help the farmers in these tropical zones, primarily in sub-Saharan Africa, but also in parts of Asia as well.

The most scarce money in this is grant money. There is investment money, where you expect a return. That’s going to have to be trillions as we get these green premiums down to go full bore, and make them fully investable, which once you scale them up, you get there.

Adaptation will always be grant money, and it has to be considered with the health grants you do, with the education grants you do, and within an amount that is sadly limited. I wish rich countries would give three times as much to poor countries, but it is not a big number. We have to make sure it is extremely well spent at a time when the African countries’ interest burden, food costs, and an inability to take more loans is meaning that the cash flows into Africa are actually going down quite a bit right now.

HANNAH RITCHIE: And carbon removal?

BILL GATES: Well, carbon removal is the one thing that will never have a green premium, because anything you do, it’s going to cost money. It doesn’t give you a product other than negative carbon emissions. Part of my personal offset is I pay Climeworks about $600 a ton to do removal. There are technologies that will clearly get us to $100. We have several, I think, that could get us to $50. It’s not an excuse in any way for not switching to electric cars or not changing cement and steel, because the scale would be too large.

If it is usable at all, it is for the part that we can’t get rid of otherwise, the recalcitrant countries, the low-income countries, or if we actually want to have a year that, if we get past where we want to be, that you can actually, maybe have a year where you’d have net negative emissions, because you’re not only emitting so much less, but you do carbon capture greater than the remainder there.

That is a very high reach, because the speed with which this thing is going to come down will not hit the 1.5 degree. If you just look at the different industry groups and countries, unfortunately that is not within practical reach at this point.

We fund a lot of amazing carbon removal companies. How much that ends up being part of the solution, that will be up to governments. I think having the low-cost solutions there at least give us some very important options.

HANNAH RITCHIE: We’ve got some questions from the audience, so I’m going to move in the last five minutes to a few of those.

We have a question from Professor David Halpern, from Behavioural Insights Team. It sounds like he’s watched your documentary many times. He said, “In your documentary, About Bill, you had a copy of the book, Behave, on the table. How does Bill see the role of behavioral science blend with more conventional technology and his strategy to take on infectious diseases, climate change, and poverty?”

BILL GATES: Well, the main area that behavioral science has come into the work I do is in health-seeking behaviors, what’s the reputation of antenatal care visits, or what are the rumors about vaccines, or how do you get farmers to take a risk on different seeds? Behavioral issues where we are a lot more sophisticated now than we have ever been, that’s a big deal in the health world.

It is a big deal in the climate world, because people want to feel a sense of engagement. What are the messages that get them to switch their purchasing to the degree that they can afford to do so? What is the thing that gets them politically activated? Can we have, across the political spectrum, people who largely believe this is an important cause? Those are areas that I don’t bring a lot of expertise. But being smart about how you draw people in, and how they choose to be exemplars in this area, is a very necessary part of the solution.

HANNAH RITCHIE: A question from Raman Bhatia from OVO energy. He says, “In the UK and many other parts of Western Europe, net zero has become a political battleground, often pitched as a false tradeoff versus economic growth. What are your thoughts on the framing of the net zero opportunity for wider acceptance?”

BILL GATES: Well, I absolutely believe that the economic model of having growth, we are not going to move away from that. That is why I am so glad that innovation lets India have better lifestyles, or sub-Saharan Africa, over time, have more energy intensification without that being a threat to the planet.

The idea that the political parties would have different strategies for how you go about doing climate change, that’s probably okay. But the idea that it calls into question, okay, is this a real thing, should this be a priority, that almost, to me, is like election denialism where it really undermines government to think about threats in the future, including weather disasters and things that it is supposed to think about – earthquakes and it being too hot for people to live. To some degree, a limited amount, they’re supposed to care about all of humanity and the stability of the globe, whether for moral purposes or reducing the migratory pressure that you come under. There are a lot of reasons why having solidarity with poor countries make sense.

I would be very sad if climate in the political dialogue becomes like it is presently in the United States, in other countries.

HANNAH RITCHIE: I would like to thank everyone for coming. Thank you very much, Bill Gates. [Applause]

BILL GATES: Thank you.