Sam Stephenson: the goal of a Cambridge PhD

Dr. Sam Stephenson has just completed his PhD in Energy, Climate, and Net Zero Policy in the Department of Engineering, Cambridge University.

In this episode, Sam describes a benchmark report from the UK government-funded research group he worked with at Cambridge, known as UK FIRES. The report, Absolute Zero, and others from UK FIRES can be downloaded here:

https://ukfires.org/impact/publications/reports/

Absolute Zero has been downloaded 175,000 times since it was published in 2019, and comes from more than a dozen researchers drawn from five universities: Cambridge, Oxford, Imperial, Bath, and Strathclyde. The top line finding in the report is that in order to decarbonize, the UK should begin to reduce energy demand to 60% of the current usage in order to more quickly match the supply from zero carbon sources, and complete this transition by 2050, achieving the net zero goal that is part of UK law.

Sam also describes his current research and how he initially chose climate change as his focus, which first led to a masters in environmental economics and now to his PhD.

We’re at an inflection point in history; at the time we post in August, 2025, a heat wave hovers over Europe, where southern France is expected to reach 109°f/43°C, and the northeast United States remains under a summer-long plume of smoke from wildfires in Canada. IPCC co-chair Robert Vautard reports that extreme heat waves are doubling in frequency on a ten-year basis, meaning 2035 will experience double the number of this year.

Pierce Siegel, a rising high school senior in New York City, Cindy Ye, about to begin her first year of college, and Ahana Pairee, moving from India to begin graduate school in the UK, each draw Sam out with questions about what the future is likely to hold and how to make it work best for everyone: with collective understanding, realism, optimism and determination.

Additional references for this interview are included at the foot of the transcript at this URL:

https://newyork.thecityatlas.org/people/sam-stephenson/

Pratibha Priya, David Case, and Helena Rambler also contributed to the questions for Dr. Stephenson; moderation and post production by Cindy Ye.

Send us your thoughts about Bridging the Carbon Gap at podcast@thecityatlas.org.

Transcript

Sam Stephenson 

Fri, Aug 01, 2025 3:22PM • 1:09:14

SPEAKERS

Sam Stephenson, Cindy Ye, Pierce Siegel, Ahana Pairee

Sam Stephenson  00:03

We are building a new future, okay? And that requires a lot of technical expertise, but it also requires a lot of creative and big picture thinking about what is the future that we want to create, okay? 

And so we need people to have a vision of that future and be able to discuss it, and argue it, and imagine it. And it's only through this collective understanding and creation of the future that we can then go out and build it. And as I said, that's got to be rooted within a technical understanding of what is possible to do, but with both sides of it, about understanding what is possible to do in terms of a technical construction point of view, but also having that vision of what we're working towards as well, and then having that sufficiently diffused throughout the entire kind of population, and so that we all kind of feel like we're moving towards somewhere which we can collectively agree on.

Cindy Ye  01:00

Because climate change is not formally taught in New York City High Schools. City Atlas started this podcast to connect high school students directly with experts to find out how they would design a high school curriculum for climate.

My name is Cindy and I'm a senior at Stuyvesant High School. We spoke with Sam Stephenson, who has just gotten his PhD in Energy, Climate and Net Zero Policy from Cambridge. 

His current research is within the Department of Engineering at Cambridge, and explores the limitations of techno optimistic climate policy. In this episode, we talk with him about how he became involved in climate work, a paper from UK FIRES called Absolute Zero, and his thoughts on the future of decarbonization. 

Having read Absolute Zero, a paper from UK FIRES, a group that you work with, I find it to be an amazing call to action for all of society on what to do to avoid the climate crisis, for businesses, the government and the everyday individual. The papers influence can be seen by how it's the most downloaded paper from Cambridge on moving towards a green future. Could you tell us a little bit more about Absolute Zero? 

Sam Stephenson  02:12

I joined the group in the aftermath of Absolute Zero to try and deal with some of the political and economic challenges that arise from the key messages of Absolute Zero. But, of course, happy to talk about it. I think it's worth giving some background to the context within which absolute zero was produced and kind of came onto the scene, which is to say that in 2019 just after the UK had kind of introduced its net zero target. [Before that,] We had a target that required 80% emissions reductions by 2050 and they updated that kind of for a number of reasons, including, kind of the Paris Agreement, but also a number of political reasons to say that we are going to try and get to net zero by 2050 and that has a profound impact on the political aspects of decarbonization of net zero, because until that, there were a huge amount of people, industries, organizations that were almost hiding within that 20% remaining emissions that was going to still be existing in 2050 you had airlines saying, Oh, we're going to be the 20% that's still using fossil fuels in 2050 and shipping saying, Oh, we're going to be the 20% that's still in 2050 and cement production saying, we're going to be the 20% that's still operating in 2050 and you add all of this together, and surprise, surprise, it's more than 20% of UK emissions, but also global emissions. 

And so Absolute Zero was really interesting in that it removed that hiding place and meant that everyone has got to get to net zero emissions, whether kind of individually or as a society. 

And so that left a kind of space to say, Okay, well, what does it mean for every single actor, every single sector, every single person, to have to get to net zero emissions and and how can we, what are the parameters, what are the conditions within which we can realistically do that? 

And so how they went about trying to understand that, and how to demonstrate that, is to look at in the first question, well, how much energy and how much stuff are we going to have to be able to play with and be able to use within this net zero economy? How much clean energy is really going to be available? How much green hydrogen, how much carbon capture and storage, all this sort of stuff. 

And this approach is somewhat unique within the analytical world in which we exist. To say, kind of like, not how much do we need to do the transition, but first off, starting from a principle, how much is going to be available, how much, how much we really going to have given, kind of current rates of deployment and how fast it takes to build things and all this sort of stuff. 

And they they basically looked at how how long it takes to build different types of technology, different types of clean energy technology, specifically, and came up with an estimate that said that we are only going to have 60% of the current total amount of energy that is used in the UK available, based on how fast it takes to build wind turbines and solar power and batteries and that sort of thing. And critically within that, given that we currently haven't been able to build any carbon capture and storage, and also the energy limitations around using hydrogen, using electricity for hydrogen, we're not going to have any of these new types of technologies that are kind of seen as these, these kind of silver bullets within decarbonization agenda, specifically, specifically carbon capture and storage and then hydrogen. And so this gives a kind of a very tight foundational framework within which decarbonization has to take place. 

And then you start to ask questions of, okay, well, how do you deliver the proximate same amounts of services within this reduced amount of energy available? 

And the first thing we did, or first thing they did, is to say, kind of like, what are the decarbonization options available to different sectors and different activities. And so you look at like transport, like road transport, for example, and we say that, all right, the energy transition is happening in this sector. We're moving towards electric vehicles and that sort of thing. How much electricity is it going to require to decarbonize the entire car fleet. And we get, I don't have the numbers on top of my head, but you get this kind of very large number, and you say, well, that would use up X percentage of our total amount of energy. What can we actually do to bring that down in terms of kind of it's not kind of feasible or fair for road transport to take up 50% of the total energy available in 2050 and so we have to work out so we have to work out how we can kind of proportionally allocate these different sectors to the total amount of energy available, and then use that to try and look at energy and material efficient measures that we can do to bring that down. So, for example, making lighter vehicles, making smaller vehicles, but also kind of driving less. And look at using public transport where available. 

And so this is all a kind of a background, a framework to say that when you have this constrained amount of energy that's going to be available to us in the future, we really need to start thinking kind of in more detail about every kind of joule at every kilowatt hour that we're using, and making sure that we're kind of using it to its maximum efficiency. The second thing to think about is when we assume that decarbonization, when we assume that these new technologies that a lot of sectors rely on aren't going to be available, what does that mean for sectors that are currently depending on it? A big, big example of this is the airline industry, which is currently kind of putting all of its eggs in terms of decarbonization in these future fuels, whether it's hydrogen or sustainable aviation fuels, and one of the things that you kind of comes out of this is how inefficient it is to make the fuels that are required for these technologies. 

Cindy Ye  09:03

Really quickly, net zero is the UK government's net zero policy goal, and Absolute Zero is the UK FIRES report.

Sam Stephenson  09:15

Yeah, so net zero is both the kind of policy target within the UK and a large number of other countries also have similar net zero targets. And what net zero means is that by 2050 any emissions that you still have in your economy have to be met by an equivalent number of emission drawdowns, emission capture. And that can be kind of what we call natural carbon capture. So things like trees or agriculture and this, yeah, peat use, if you know what that is, a kind of a way of the land, kind of sucking up carbon from the air. And also technology like carbon capture and storage. So this is direct air capture, or carbon capture, on the top of plants that suck out the carbon before it could be emitted into the air. 

And so the idea is that, yeah, any emissions that are still happening, you have an equal amount of negative emissions that offset the other and then you get to a net zero number. 

What the Absolute Zero report says is that the amount of negative emissions available to us in 2050 is going to be essentially zero. Okay, we're not going to have these technology derived carbon capture techniques, because it's just too difficult to build any significant level. You might have small, small bits, but kind of on the level of that we're talking about, we're not really going to have any available. And the natural carbon capture sinks that we currently have are going to be required to offset the kind of natural emissions within nature, the world that we see, and so we can't really rely on them to offset our kind of anthropogenic emissions. And so that's when you get to an absolute zero number. You have to reduce emissions to actually zero, not just offsetting them with technical means of carbon capture. I guess. 

Pierce Siegel  11:21

To add onto that, how would you respond to criticism that this absolute zero pathway is politically or socially infeasible.

Sam Stephenson  11:29

I think it's a it's an incredibly valid criticism, and I think there is a huge amount of of work that still needs to be done in terms of trying to kind of bring to light this trade off between what is technically feasible and what is politically and socially feasible, and the way that I would frame the Absolute Zero report, and I'm speaking for myself here, I'm not speaking for authors or other people, is to say that the Absolute Zero report and the Absolute Zero agenda is a kind of a line or a flag in the sand, to say this is the maximalist opinion or the maximalist position. I should say, of what needs to happen given our current rates of technology expansion, our technology deployment. It is not at all kind of set in stone or guaranteed that we're going to have carbon capture, zero clean hydrogen. 

Things could change. There's still 25 years till we get there, but you as political actors and political people have got to go out and make that change. And change the rate of deployment, change technology, change the technology makeup of my country or your country, and particularly if you're going to do that, then you've got to do things, like, you've got to put investment into it. You've got to put money into it. You've got to relax the kind of the planning regulation, or the planning restrictions to allow you to build these new things and that sort of stuff. 

And so it's kind of at our current rate, in our current situation, we're not going to have these things. 

And it's also very hard to do it, okay? It's very hard to build large amounts of carbon capture and large amounts of hydrogen, just to use examples, or even increase the rate at which we're building offshore wind or batteries and that sort of stuff. And so this is kind of what needs to happen within the current regulation. And I admit, like, I don't want to stop flying. Okay? I don't want to stop kind of the global transportation of goods and that and that sort of thing, but we do need to find this ground within which kind of we reduce the amount of which we are kind of relying on these future technologies and these future kind of activities to meet the demands of our current current system, which are technically infeasible.

Ahana Pairee  13:46

You did mention just now about having to live in a low demand future as opposed to where we are today, and this could seem dystopian to some people. This could feel limiting to some people. So I think, how would you say that a low demand future could also offer new sorts of freedom, as opposed to just restrictions or limitations?

Sam Stephenson  14:11

Yeah, that's a really good question, something that I think needs to be kind of developed and built up. When we're talking about this, it's very easy to kind of highlight and point out the negatives, or, as you said, the kind of the restrictions that come from this sort of decarbonization picture that we're talking about. But I think there is a vision of the future that can allow for this more energy, material efficient world, that is better for everyone, and that comes in two parts. For me, it's a question of who has to change, and who is going to be impacted the most by this, and what is the kind of vision of the future that we are creating within this change. And so the first one is, we are targeting the people that are doing the most emitting, okay? And that is as, as all the evidence suggests, the very rich, the richer you are, the more emissions you have, and the more high emitting lifestyle activities that you do. 

The vast majority of the people of the world, but also in developing countries, think about who specifically is going to be impacted by this, come to a kind of collective understanding of who needs to make these sacrifices, who needs to change, and who actually would be impacted less by this. Think about in the UK, like the people at the very bottom of the income scale wouldn't really be impacted by restrictions on or changes to kind of the way people drive and get around, because the most of the time they get in the bus places, the most time they're walking places. 

And actually, if we take that and invest in better public transit, public transport infrastructure within cities, we are actually then doing that as a way to help everyone that relies on these services. 

And then I think the second element to that is also to try and kind of think about what the alternatives are, and actually how kind of both limiting and impactful a lot of these kind of constraints can be, if we think about the people that fly the most, that are kind of like flying backwards and forwards between, kind of, London, New York for business meetings. It's a horrible activity. I know people kind of say they need it, and I know it's really not a nice way to kind of go about, kind of, I think your life spending so much time on flights and that sort of stuff. And so we can create a world within which we spend less time stuck in traffic jams, less time stuck in airplanes, less time kind of doing these things which we don't like. We can create a more energy and material efficient, but also a more time efficient thing. 

And talk about what that means in terms of what you get for those trade offs. Do you get more time with your family? Do you get more time to do low carbon leisure activities? Do you get more time to pick up hobbies that you haven't previously had had the time for because you're stuck, as I've said, kind of in a traffic jam, or kind of stuck on the tube and that sort of thing, and then. I'm not saying that's kind of a universal, everyone's going to benefit. 

We know one of those undiscussed elements of decarbonization is that we are going to have to reduce our meat consumption. It's not really feasible for everyone to eat meat as we do within the Western world. And Western meat consumption is incredibly problematic. And so we need to have a conversation around how we are going to kind of balance these global needs with the enjoyment that meat, that meat consumption brings. Like, I know people really enjoy it. I know people enjoy the taste and that sort of stuff. And so these are genuine, difficult, big, complex questions that we need to tackle. And I'm not saying I have the answers. I'm not saying really anyone has the answer, but I think also then, both extremes don't really get you anywhere. So that's kind of why we need to start being honest with people and saying, Look, I know it's really hard. I know kind of it's really delicious, or you find it really delicious, but it's just like the planet is going to burn if we all do it three meals a day, 365 days a year

Cindy Ye  18:13

To shift the public view on decarbonization, like you just said, we find out one really good place to start is education, which is the focus of our podcast here. Can you discuss what UK’s K to 12 looks like in terms of what about climate is taught to students, and also, how do you feel your own high school education prepared you for the topics you're discussing now, and the work you're doing?

Sam Stephenson  18:43

Yeah, I will level with you that I was in primary education, as we call it over here, a long time ago, and so I don't have a particularly good insight into what is being done, kind of day to day, within the climate education space. I know that when I went to school, so I left school at 18, over a decade ago now, and there was very little, if any, discussion of the climate crisis, or the environmental crisis going on within the academic curriculum. And it was only really even after finishing my undergraduate that I became aware of a lot of these problems. I know a lot is changing. I know a lot of people that do a lot of good work trying to bring these questions and bring these areas to the curriculum. And in particular, the existence of the climate crisis is now a thing that is kind of taught and recognized within schools, but in terms of questions of mitigation adaptation, I'm not, I'm not sufficiently, versed on how these are taught in schools.

Cindy Ye  20:07

And I know that you currently work with a lot of engineers, as you've mentioned, can you perhaps talk about how universities and engineering schools, if they're doing enough to train our future professionals in this zero based thinking and design, and if not, how can they, because as I'm about to go to college for engineering myself, and as I'm looking at these college courses and curriculum, there's very little emphasis on climate related courses. And I'm curious if the UK is similar.

Sam Stephenson  20:41

Again, I can't speak for the entirety of kind of the the engineering higher education system here, and every university has given a lot of flexibility and freedom to to structure their courses how they want. What would they, within certain boundaries? Two good things that I will say is that I think that one of the things the engineering departments and degrees and profession as a whole does very well, which is missing in other areas, is the ability to apply complex systems and system dynamics in general, to which are incredibly applicable to kind of climate systems, but then also to the sorts of decarbonization topics that we've been talking about here, in terms of the the relationship between moving to more public transit or more electric vehicles, and then the impact on the electricity grid and the impacts on how people move around cities, or how people get to work and that sort of stuff.

The engineering discipline as a whole, I think, does a very good job in getting you to think in these ways around, kind of like big picture, like complex systems thinking and how these different elements relate to one another, and then be able to kind of break it down and process it in quite structured ways, in terms of thinking about what is the boundary of a system and what is within this boundary, and what is kind of crossing over the boundary and crossing out the boundary.  I've been able to apply complex analytical tools and procedures to understanding these really difficult problems. 

Where I think that universities as a whole could improve is there is still a lot of focus on the kind of engineering systems, you might say, of the 20th century. And so I know there is some debate, I won't kind of comment on whether it's big or small, around the teaching of how internal combustion engines work in engineering departments, given that internal combustion engines are not going to be a thing in the future, and there is a movement within a number of universities to basically phase out the teaching of the engineering of the internal combustion engine for new undergraduates, which I support, given that we're going to have less and less than over time. And then a kind of an inverse opinion, which is, say, kind of, even if you don't have internal combustion engine in the future, engineers technicians are still going to be have to understand kind of the underlying principles and ideas that these systems and that these kind of technologies rely on, and what underpins them. And so kind of this is just a way of teaching these underlying facts and kind of like ways in which these systems work. 

But I think there is kind of broadly a need to kind of move towards both teaching the kind of the skills and knowledge and expertise of the clean energy transition. 

So that is kind of understanding how solar panels and electric vehicles and wind turbines actually work within engineering departments, which I haven't seen a lot of maybe, maybe it is there. I haven't seen it personally. And then I do think that again, still teaching these kind of technologies of the 20th century, in some way holds us back from truly accepting that we are going to be in a different 21st century. I hope that doesn't put you off doing an engineering degree, because I still think it's incredibly valuable, and I'm still very happy to hear that you're doing it.

Pierce Siegel  24:41

In line with that. We were just wondering, how did you get into wanting to study the climate crisis and what's continued to motivate you to stay in the field and continue research?

Sam Stephenson  24:55

Yeah, good question. Yeah. So my background was in maths and philosophy, which essentially kind of a product of me being unwilling to choose between the two things in school that I found very interesting, and not wanting to, not wanting to kind of narrow myself down into one or the other. And I think at the time, I didn't really understand how that was kind of setting me up to think about the climate crisis, but it did a huge amount to open my eyes to both, I'd have questions of global justice and ethics and all these sort of things that I think are incredibly relevant within the climate crisis, and then also kind of how to think technically and analytically about these same problems and tackle them in, yeah, analytically rigorous ways. 

It wasn't until I actually finished my undergraduate that I kind of came out and people are asking what I'm gonna do, and I think there was one question within it, so why aren't you working in the City that someone has put in the the questions here, which was kind of the natural kind of progression, and I realized that I wasn't, didn't really want to go work in the City. You do all these job applications like, Well, why do you want to work for X firm? And I didn't really have a good answer for why I wanted to work for whatever firm it was that I was thinking about. 

And essentially, I spent a lot of time reading around and thinking about what it was I wanted to do. And I ended up essentially being inspired by a book by Naomi Klein. I don't know if you've come across her. She wrote a book probably about 15 years ago now, called This Changes Everything, which is about the impending climate crisis. And yeah, this book essentially changed my life. It put me on the path that I’m on now, and it really breaks down and evidences and emphasizes the relationship between the climate crisis that is unfolding and the global economic system within which we are operating, and how It underpins and drives this crisis. 

And I read this, and read a bunch of other things, oh, my God, this is it, this is the problem. This is what I want to do. And so after, after making that decision, I went back and did a master's degree in environmental economics and climate change, which is kind of my way of wanting to get a better understanding of this relationship between the climate crisis and the economic systems which underpin so much of our life. 

I then did end up working in policy consulting for a period of time after that, before realizing that no, my true passion is within academia and doing this PhD. 

To go back and or, to add to that final point of what keeps me going, a lot of it comes back to that original kind of book and realization that I had around, like this is, I think, one of the defining changes and transformations that will happen throughout our life. And I say will because, whether it is the transition to a kind of clean green economy of the future, or a transition into kind of some climate impacted world, we know there is no kind of continuation of the current status quo, or kind of business as usual scenario, which a lot of people talk about, and so trying to kind of move us towards this, this kind of positive, optimistic vision of the future that we've talked about before is why I do this. 

And I also think the this is a really kind of exciting time to be in this kind of conversation and these actions around the green transition. I think over the over the last kind of five years or so, maybe, maybe 10 years, we've seen both kind of the uptake of the climate crisis, climate change and the environmental crisis as global issues with which we've got to grapple with, and change our system to adapt to, and then also now we are seeing kind of clear backlashes to this, kind of reactionary attempts to this. 

But there is a very clear understanding that I don't think we are going back, despite how much some groups and some people want us to.

It is just a fact that electric vehicles are more efficient than petrol and diesel cars. It is a fact that clean energy technology, wind turbines and solar panels are cheaper than burning gas and more reliant when you think about batteries and than gas, which is kind of incredibly volatile, as we've seen these past couple of years. 

And so the question has become much less of, how do we get people to, how do we get policymaking politicians to wake up to it. Now, something I'm much more interested is, kind of, how do we grapple also, how do we grab the opportunities that come from the green transition and make it a transition that we want to kind of have in the future? How do we, how do we turn it into something that is desirable for everyone and also has kind of the larger economic and societal benefits that we know we can that can come from it, whether it is kind of economic development of of kind of the Global South, or kind of revitalization of communities that be left behind within developing within kind of the Global North, whether it's a move away from systems that, as I've said before, require us to sit in traffic jams and on crowded undergrounds for two hours every day, and kind of we know it's happening, it's just on us to kind of grab it and shape it into the transition that we want to see of the future. 

I did my PhD looking at the kind of proliferation and generation of net zero pathways primarily focused in the UK, but with global application. That's happened in the past, kind of five years or so. And what they tell us about competing visions for net zero, how viable they are, why they're developed in certain ways, and kind of what we can do to kind of push these visions of the future into something that we think aligns with the kind of techno constraints of building and energy systems and other things like financing and that sort of thing as well. 

And I shifted focus slightly to, I’m now much more focused on the role of critical minerals and critical materials within the green transition, the net zero transition, and looking at how the need for increased extraction and consumption of net zero materials, of critical minerals and net zero materials, more generally, can be done in a kind of both sustainable way and then, particularly, given that a lot of these materials are in developing countries, how we can essentially, kind of extract these and decarbonize in a way that doesn't repeat the sins of the past, and the last time we tried to develop. So looking at what it means to have to extract these materials, looking at how they can be used to support development in these countries, and yet making sure we don't have repeat harms of the past.

Cindy Ye  33:23

You talk a lot about getting these materials in a more environmentally friendly way. Do you see society as needing to make any sort of sacrifices to really get to that goal of avoiding the climate crisis?

Sam Stephenson  33:43

Yes, so I think it depends which kind of approach and which lens you come from when we're talking about critical minerals. 

Specifically, it is kind of somewhat unavoidable that these materials are required if we're going to have kind of an energy transition and also be able to continue living in some sort of developed economy, having electricity, having transport, having all these things. 

And there are ways in which kind of critical mineral extraction can be done well, and particularly in terms of supporting local communities and working with local communities and ensuring that kind of when this extraction has happened, more of the kind of economic benefits is kept within the kind of countries or regions within which they're extracted, rather than just kind of like taking it elsewhere.

And there's obviously very bad ways in which it can be done, and there's plenty of examples out there. I think, at the global level, on the pitch of the scale of the energy transition more generally, there's a bigger picture, a bigger conversation that needs to happen about how how fast and how much stuff can be done at once, and kind of what is available to us in terms of technologies that can kind of be deployed at scale. 

And I think when you start to look at the numbers in terms of just how much new stuff we have to build, how many new pylons we have to build, how many wind turbines we have to build, how many new electric vehicles we have to build, or we can go faster than we're currently going. But I think at some point it's gonna have to be a conversation between kind of like how fast we can go and what we actually, what place we end up.

Cindy Ye  35:34

We know you have a background in economics, and as we see more of these structures, like wind turbines built, how do you see this impacting the stock market and global exchanges?

Sam Stephenson  35:48

Yeah, it's a really interesting question, and something that I don't really think kind of gets enough attention or consideration. We know that the transition to net zero is going to have kind of radical and systemic effects across all sectors of kind of social life, economic life, financial activity. And this is kind of will ultimately and inevitably be reflected within the stock market. 

One of the stats that I always like to come back to is that I think over half of global shipping is currently used to just move around fossil fuels from place to place. And so if we move away from fossil fuels, kind of inevitably, the size of shipping industry is going to get half as big, with implications for both kind of workers and people doing that work, but kind of the stock price of these, of these shipping companies, and I think a huge amount of kind of the reason why these transitions and these impacts aren't currently baked into the the stock price these companies is a huge is the promise of these future technologies and these future kind of opportunities that I talk about as a lot of my work things around kind of like clean hydrogen or carbon capture and storage, which are seen as both, kind of like alternative ways of doing things that don't fundamentally kind of disrupt the way in which energy and kind of materials flow around The global economy. 

One interesting thing about hydrogen is that it's still something that is kind of liquid and then also burnt or gaseous, I guess, and also burns. And so you still have to transport it, moving around and that sort of thing, which allows you to keep in place all the existing structures. 

And similarly, with carbon capture, the promise of carbon capture is that we can continue to move around and burn and then extract fossil fuels in the same way, which doesn't disrupt the system. 

So that's why we haven't seen this kind of required change baked in, in terms of the point, what would actually happen to the stock market? I'm not in a position to give that sort of advice, and I think it depends on the nature of the transition would end up happening if we kind of got our act together as a global community, and kind of did this big effort to move from fossil fuels towards kind of wind turbines and and solar panels, all these, all these sorts of things you would inevitably see, like the stock price of the stock price of fossil fuel companies going down, but probably, probably other companies kind of like increasing their profits, increasing activity to make up for it, and then you'd have all these intermediate players that are doing the transition, like car companies. 

I'm not in a position to say that. I think, though, one of the things we do have to bear in mind is the way in which so much of economic well being within the developed world in particular, is linked into the stock market. And we will have seen this within the past couple of weeks, with the impact on the stock market from the from the new tariffs in the people are losing their retirements. People are losing their savings. And this is a big issue, given the uncertainty that is going to arise from the transition and that impact on the stock market, I can't tell you what is going to happen, or even if it's going to go down or up, but there is a huge risk underlying that, given that there is kind of an increased possibility of the stock market going down, let's say, and the impact that would have on everyday people through retirements and savings,

Cindy Ye  39:29

Every country sort of chases after this idea of progress and in their minds the idea of progress often can be continuous GDP growth. Do you see that as compatible with an Absolute Zero future? And how do you imagine countries sort of realigning their priorities as having the environment and the health of it be more prioritized, and also is GDP growth the correct measure of success in a future where we're trying to avoid the climate crisis?

Sam Stephenson  40:07

Yeah, a series of really excellent questions there. I think the best place to start with is at the end. And I think it's quite widely accepted these days that GDP is a bad measure of the economy. I think actually, even the most mainstream of economists would probably tell you that GDP is not a very good way of understanding what is what is going on within the economy, and that it creates a bunch of perverse incentives to ensure that kind of the line goes up quarter on quarter, month on month, year on year. Without any kind of any real long term consideration for how sustainable these activities are, sustainable in the environmental sense, but even sustainable within a business sense. You might, you might think about it in that way, and so I think we need to deprioritize GDP as a metric of understanding our economy and of the society as a whole. 

What we replace it with is something I don't have a have a particular answer to, I'm afraid, but in terms of what happens to kind of GDP in that sense, over the course of the transition, someone wants to use the once used the phrase me when, when referring to kind of questions around de-growth or or clean growth or green growth, that they were GDP agnostic, which I think is kind of where I come down onto it, which is to say that I don't know whether GDP is going to go up from the green transition. I don't know where the GDP is going to decline from the green transition. I don't think it really matters in the long term. As we talked about right at the start, there are some kind of considerations. In terms of how much people's retirements and savings are linked to the stock market. But overall, I think that we shouldn't kind of prioritize how these activities kind of impact GDP or economic growth, we should have deprioritized that as a metric that we consider out and then think about actually, what are the impacts on people, society, everyone's well being, everyone's happiness, and that sort of thing as well.

Pierce Siegel  42:38

I think that's really interesting, just to continue with that for a second, if we think about a different indicator, consumer confidence, we haven't really seen climate change affect aggregate demand yet. And at what point do you think it will in the future? Is there going to be like a natural disaster that will hit, that will finally wake people up, or will that like, not cause GDP to lag in that way?

Sam Stephenson  43:10

Now you're asking the difficult questions. I think the question of, kind of, will people wake up to it, and will they kind of see it, will we see it impacted in the metrics or the statistics, is something that I don't think we can know, but I guess something to be kind of somewhat skeptical or hesitant about. 

I’m assuming a number of us have seen the film Don’t Look Up from a couple of years ago. And kind of the main takeaways from that, which I do think kind of is an apt metaphor for how we are kind of treating and continuing to treat the climate crisis, that people will just not, not believe it or not look up, as they say, and that is a kind of a real concern and real impact. Oh it’s a real concern that we need to be aware of. 

That being said, while we may not be seeing it in the kind of consumer level indices and data that we have available, it is starting to show up in a large amount of the kind of underlying core economic data, not in terms of GDP, but other things that firms and economies rely on. 

If we think about insurance rates and reinsurance rates, we're seeing large, large parts of particularly in the US, given how kind of insurance and how much insurance underpins your economy over there, large parts of California that can't be insured against wildfires, or large parts of Texas that can't be insured against kind of floods and hurricanes and that sort of stuff, which with impacts on people's livelihoods, which fiduciaries take seriously, as we've said, but then also the ability to buy and sell houses, the ability to move, the ability to actually protect against these natural disasters. 

And so I don't think that it's one single natural disaster that is going to kind of impact at such a level that is really going to kind of wake people up and see the impacts of the climate crisis. But we are starting to hear kind of accumulation of long term trends of the climate crisis, both in terms of the number of natural disasters, but also just kind of the increase in background temperature that is kind of causing all these things and impacting food production, migration patterns, all these different elements, water availability, that we're starting to impact economies in major ways, and at the current kind of moment in time, it's not reached a significant level, but it is something that they need to be aware of as a kind of a major impact within the next 5, 10, 15 years.

Cindy Ye  46:13

As we talk about government action, what sort of governmental fiscal policies could you see being implemented? For example, carbon taxes to accelerate this change towards a green future, and at the same time, how might you see businesses and the market shift into rewarding sustainability and also durability rather than profit?

Sam Stephenson  46:39

Yeah, excellent questions. I think that the fiscal policy put in place by governments will have to be dependent on the type of economy that currently exists and kind of the type of economy within a certain place. 

And so the fiscal policy in the UK will have to look very different to the fiscal policy of the United States, for example, but also the fiscal policy of Vietnam or China or Japan and these sort of places. 

So I don't think it's particularly useful to talk about at the global level, nor do I have the kind of requisite background or knowledge to talk fluently about these places. The thing that I will say is we need to tailor these, these fiscal policy decisions, to the place, to the nature of kind of the both the emissions and the impact on climate and the climate impacts on these economies where they are so in the UK, I am not sure that kind of the fiscal policy should be targeted so much at emissions reductions in kind of domestically, although, obviously that's still something we want to bring down, we still want to target. 

But where the opportunities come from the government is in terms of providing these economies of scale and these cascading benefits of kind of climate innovation, climate technology, or demonstration policies, in terms of how different fiscal economic policies can unlock decarbonization action. 

One of the very significant success stories of UK policy is something called a contract for difference. I won't bore you too much with the details, but it's essentially a way of government guaranteeing the price for renewable energy generators, if the market price is too low that they make their return on investments. 

And there's a large number of kind of social critiques around the government paying private companies, if they could be doing it themselves, but it has led to both the proliferation of particularly offshore wind in this country, but other clean energy technologies, and a cost reduction of these same things, and that is now being kind of exported to other countries as a kind of model for clean energy deployment, government backed clean energy deployment that has been successful, whereas, if we're looking at other places, potentially places that are kind of either much more manufacturing heavy, the fiscal policies would more likely need to target them, or places where climate adaptation, which is not something we've touched on that much, and is kind of much more important fiscal policy focused on, yeah, adaptation, in addition to mitigation, is something that requires more attention, but not something I have necessary skills to really talk about.

Ahana Pairee  49:59

So we did like brush upon the fact that different countries handle things differently, and based on their systems and everything in place, is there anything any other countries or movements that come to your mind, apart from the UK, where you think that they have done a better job of handling climate justice, or any kind of system level changes?

Sam Stephenson  50:22

So there are countries and groups that are definitely doing better jobs at kind of thinking about questions of decarbonization and climate justice. And Costa Rica, for example, comes to mind as a kind of a quite a well versed example of this. But I think it also comes back to considering these countries and these kind of actors within the kind of economic and geopolitical situations within which they find themselves, and working out what we can take from each place and apply it to other places. 

And so the success of a place like Costa Rica may not have a huge amount of lessons learned for a place like the UK, but I think could be an example for other countries within South America or even places in Asia. I'm not going to go get too much in specifics of that, given I don't, don't really know that know the details. And similarly, I think some of the ideas proposed by the European Union and the European Commission over the recent years are, if somewhat poorly, poorly deployed, have been saying the right sort of things in terms of specific targets and policies around not just expanding clean energy deployment, but also reducing total energy consumption through energy efficiency measures and that sort of thing, or trying to target the material efficiency of goods, making things last longer, opening up ideas around right to repair, and these sorts of things that take a long time to come through. And I think this is where you could start to see different geographies feeding into each other about how you set the right targets, but also do things faster, because, yeah, the European Commission is notoriously slow about these things, but has the right idea about a number of them as well. 

Ahana Pairee  52:38

I was just wondering, I know you said that you don't remember too much from school, or like what was thought there with regards to all of this. But if today you had to clear one misunderstanding about net zero, how it's sort of explained to people at a younger age, or as an introduction, what would be something that you would talk about or or put forth first?

Sam Stephenson  53:13

So I think when we're thinking about climate change, the environment, and the education around it, I would be less focused on how questions around the climate crisis itself are taught. I think that the educational data around how it's like, how increases in greenhouse gas concentrations globally are increasing global temperatures and leading to increased natural disasters are, is already being taught is, again, I don't know, but probably done quite well and kind of done in an age appropriate way. I think, where I probably try to target interventions is when we get into questions around mitigation and our responses to it. 

And I don't know how much this is touched upon in school, but particularly with the kind of the larger conversation around it is still primarily framed as an economic challenge, as a challenge that is both economic in nature, in terms of impacts, but also what the solutions are. And I think the intervention I would have is to increasingly think about it as something that is a problem rooted in engineering.

What do we need to build? How do we build them? What are the knock on consequences of building these things in terms of, okay, well, how do we get the wind power that is produced way out to sea to the cities in where it's consumed and where it is used? 

And how much of these different things do we need? How long does it take to build kind of, can we look on a map and see kind of where these lines would go? And, okay, well, and then you start to bring in the kind of ethical, political, economic considerations around, well, what does it mean to build a pylon over this community? Really rooting within the kind of technical changes that need to happen, and how fast they can happen, and where they're going to happen, and then layer on the kind of more sociopolitical aspects on top of it, rather than the reverse, which is kind of how I think a lot of these problems are understood, if not taught.

Cindy Ye  55:57

Sort of on that vein, how would you design this ideal high school curriculum in line with, let's say the Paris Agreement goal, or the report Absolute Zero, or just any values that you see are important for working towards a future where we avoid the climate crisis?

Sam Stephenson  56:20

Yeah, I think along those same lines. There's two things that need to happen. And I would root it less in a question of teaching people what we need to do to avoid the climate crisis. I think if you want to kind of be involved within the green energy transition, be involved within it, from a kind of a political or an economic or a technical engineering based approach, kind of we need to develop better courses and better ways of doing that. But I think within the broader curriculum, which everyone kind of experiences, I think we need to again, provide a greater understanding of kind of how things operate, how things are built, how things change, the rate at which we can build things, actually, the fact that the transition is built on the production of wind turbines and solar panels and that sort of thing, and a kind of a stronger understanding of how these things go about getting built and that sort of thing. 

And then mirror that with, or kind of pair that with a larger kind of conversation around ethics, responsibility and justice, but in a very forward looking way. Okay, what is the type of future that we want to kind of have going forward? What can we learn from the past in terms of what's happened in the past 10, 15, 20, 50, years that we like and we don't like? And I guess we can kind of, in terms of thinking about the curriculum and with this, which is to say that we are building a new future, okay? And that requires a lot of technical expertise, but it also requires a lot of creative and big picture thinking about what is the future that we want to create, okay? 

And so we need people to have a vision of that future, and they'll discuss it and argue it and imagine it. And it's only through kind of, I guess, this collective understanding and creation of the future that we can then go out and build it. And as I said, that's got to be rooted within a technical understanding of what is possible to do, but without both sides of it understanding what is possible to do in terms of a technical construction point of view, but also having that vision of what we're working towards as well, and then having that sufficiently diffused throughout the entire kind of population, and so that we all kind of feel like we're Moving towards somewhere which we can collectively agree on. 

Cindy Ye  59:08

And to sort of end this off with one final question, in, let's say 2050, or far into the future, how would you envision the ideal England to look like, and it's a very broad question, so you can answer it with a lens of a specific aspect of life or the field, and so just take it as broadly or as specific as you'd like.

Sam Stephenson  59:41

Yeah, I think, I think my vision of the future is one where the collective benefits and kind of development that we all contribute towards is much more equally shared amongst the entirety of society, and that kind of goes towards the decarbonization agenda, but also goes towards our life much more, much more generally. And so it is one that is kind of clean and green and kind of decarbonized in a way that we've talked about, but also one where we are able to live our life in a way that is much more in line with these kind of like larger objectives of social well being, happiness and that sort of thing, not being forced into the rat race of our kind of current consumerist, capitalist lifestyle and approach. 

And I often return to this, this, this quote, or this idea by the British and Cambridge economist John Maynard Keynes that basically looked at the rate of productivity growth in the UK over the next, kind of 60 to 80 years, and predicted that, I don't know the exact date, but some point around now, we would all be working about 50% as much, because we could all have everything we want and with much kind of much less human input, and therefore use that time for leisure and kind of human flourishment and human well being. 

And that has not happened, because the productivity gains that we have experienced over the last 50 years have been captured by the very rich, the financial elites, and turned into corporate profit and shareholder value, rather than being distributed to the actual people doing the work. And so whenever I think about the kind of division of the future beyond just the decarbonisation agenda, I think about one in where the kind of economic and productivity gains that we know are going to happen, both from the decarbonization agenda, but also from kind of technology transition as they always happen, is one that's shared much more equally throughout society, and that provides much more free time towards the things that we actually enjoy in life.

Cindy Ye  1:02:27

Thank you for having so many great answers to our questions. Is there anything you'd perhaps want to ask us?

Sam Stephenson  1:02:37

Just the one question. I would love to kind of, and I don't know if you all want to answer this or or just a couple, but what led you to both understand the climate crisis and get you in here, but also, I guess, take that step into doing something quite active, for giving up a part of your your Saturday to do these sorts of things when you could be doing whatever you want to be doing with your Saturday?

Cindy Ye  1:03:05

I think I avoided thinking about and sort of pondering this idea of the climate crisis when I first decided to study engineering, because I found them as more conflicting paths, better than one and the same, really, and I ventured into this climate literature course in high school, and I saw sort of the beauty that a world where we really solve the climate crisis and and and are able to move on from it, and how engineering could also be part of that. And I think that sort of fascinated me and made me want to work towards a future where that is what it's like

Ahana Pairee 1:04:37

For me, I entered college without having any sort of idea about it. Obviously, I knew the broader implications of climate change, but I didn't have any sort of real grounding in it. But towards my final year, I did a course called alternate energy on a finite planet, where we sort of touched upon the energy crisis. And honestly, I think similar to what Cindy said, that threw me off the edge. I was like, wow, this is such a big problem, something that I don't know if we'll ever be able to solve. But after spending some time really mulling over it, I realized that, if anything that makes me want to work on it more, that makes me want to spend my life working on something like this, and I did a research project with my professor regarding the use of energy in artificial intelligence, and how much of the energy mix would probably be used in that. And this really made me fall in love with this whole space. And similar to you, I think it was very inspiring to hear you talk, because I'm also moving to the UK, and I want to do my PhD in in the energy space. So yeah, this is my journey.

Pierce Siegel  1:05:13

I guess, to start, I was really interested in finance and economics, and to me, there was this kind of ignorance of of climate change in those areas, and it kind of led me to to want to find out more and engage more. So I joined a club at my school and helped to lead it, and we run a bunch of events now. So it's turned into a great activity, and it's great to be trying to make a difference.

Sam Stephenson  1:06:36

Amazing, really great and inspiring to hear you guys say what got you involved in this, and why you were here. 

You might have picked up from when I was talking about my background, that I kind of came to this a little bit later. It kind of took me until I'd kind of done my undergrad and went out and realized, worked out what I wanted to do with myself to kind of come across the climate crisis. So it's great, I'm always very impressed when I see people so young trying to kind of grapple with it and make their impact. And I think it's amazing, and you should be very proud. 

And I think kind of thinking about this in terms of education and what it is going forward, and kind of, how to restructure education and kind of learn about the climate crisis is hugely valuable work. And I think trying to marry up these images of climate mitigation, the climate crisis as a technical challenge that we want to that we need to solve in terms of building the energy infrastructure of the future, but always keeping that within a bigger, bigger idea of what is this future that we're building towards, and what is, what's the future look like that we want to build to? And some, some of my friends that don't work in this space kind of always find it a little weird the fact that I work within the climate change space and spend a huge amount of time reading about it, but both in the kind of fiction and non fiction sense and reading kind of, yeah, climate sci fi stuff about the future, whether it's kind of Kim Stanley Robinson climate related stuff or or utopian work. And I think we always need to bear in mind the vision that we're working towards, and having both a clear idea in our own minds and a clear collective idea of a better world being possible. 

And I know it feels really hard at the moment. I know it feels really hard in relation to the climate crisis and how slow we're moving and how behind these targets we are, and how hard it feels with everything that's happening, kind of within the world and within politics more generally. But I think, I think within all of that, we've got to maintain this vision of the future that we want to have. Share it with other people, co-create it with other people to say that we are building towards something better, and every step we take towards doing that is a really noble and worthwhile goal. So thank you guys.