I think if we had the level of enthusiasm and public support for all climate solutions that we had for solar and wind, we can definitely solve climate change. It doesn’t mean that I’m sure that any one of those technologies will definitely succeed, but there are enough really good bets worth making.

And it’s not like solar was cheap in 2000; that was not obviously a great energy solution — there were lots of articles done about renewables never getting cheap, never being a significant part of the energy supply. So I think that’s evidence for how technological change, at a first approximation, is to a large degree the result of decisions.

Johannes Ackva

If you want to work to tackle climate change, you should try to reduce expected carbon emissions by as much as possible, right? Strangely, no.

Today’s guest, Johannes Ackva — the climate research lead at Founders Pledge, where he advises major philanthropists on their giving — thinks the best strategy is actually pretty different, and one few are adopting.

In reality you don’t want to reduce emissions for its own sake, but because emissions will translate into temperature increases, which will cause harm to people and the environment.

Crucially, the relationship between emissions and harm goes up faster than linearly. As Johannes explains, humanity can handle small deviations from the temperatures we’re familiar with, but adjustment gets harder the larger and faster the increase, making the damage done by each additional degree of warming much greater than the damage done by the previous one.

In short: we’re uncertain what the future holds and really need to avoid the worst-case scenarios. This means that avoiding an additional tonne of carbon being emitted in a hypothetical future in which emissions have been high is much more important than avoiding a tonne of carbon in a low-carbon world.

That may be, but concretely, how should that affect our behaviour? Well, the future scenarios in which emissions are highest are all ones in which clean energy tech that can make a big difference — wind, solar, and electric cars — don’t succeed nearly as much as we are currently hoping and expecting. For some reason or another, they must have hit a roadblock and we continued to burn a lot of fossil fuels.

In such an imaginable future scenario, we can ask what we would wish we had funded now. How could we today buy insurance against the possible disaster that renewables don’t work out?

Basically, in that case we will wish that we had pursued a portfolio of other energy technologies that could have complemented renewables or succeeded where they failed, such as hot rock geothermal, modular nuclear reactors, or carbon capture and storage.

If you’re optimistic about renewables, as Johannes is, then that’s all the more reason to relax about scenarios where they work as planned, and focus one’s efforts on the possibility that they don’t.

To Johannes, another crucial thing to observe is that reducing local emissions in the near term is probably negatively correlated with one’s actual full impact. How can that be?

If you want to reduce your carbon emissions by a lot and soon, you’ll have to deploy a technology that is mature and being manufactured at scale, like solar and wind.

But the most useful thing someone can do today to reduce global emissions in the future is to cause some clean energy technology to exist where it otherwise wouldn’t, or cause it to become cheaper more quickly. If you can do that, then you can indirectly affect the behaviour of people all around the world for decades or centuries to come.

And Johannes notes that in terms of speeding up technological advances and cost reductions, a million dollars spent on a very early-stage technology — one with few, if any, customers — packs a much bigger punch than buying a million dollars’ worth of something customers are already spending $100 billion on per year.

For instance, back in the early 2000’s, Germany subsidised the deployment of solar panels enormously. This did little to reduce carbon emissions in Germany at the time, because the panels were very expensive and Germany is not very sunny. But the programme did a lot to drive commercial R&D and increase the scale of panel manufacturing, which drove down costs and went on to increase solar deployments all over the world. That programme is long over, but continues to have impact by prompting solar deployments today that wouldn’t be economically viable if Germany hadn’t helped the solar industry during its infancy decades ago.

In today’s extensive interview, host Rob Wiblin and Johannes discuss the above considerations, as well as:

  • Retooling newly built coal plants in the developing world
  • Specific clean energy technologies like geothermal and nuclear fusion
  • Possible biases among environmentalists and climate philanthropists
  • How climate change compares to other risks to humanity
  • In what kinds of scenarios future emissions would be highest
  • In what regions climate philanthropy is most concentrated and whether that makes sense
  • Attempts to decarbonise aviation, shipping, and industrial processes
  • The impact of funding advocacy vs science vs deployment
  • Lessons for climate change focused careers
  • And plenty more

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

Producer: Keiran Harris
Audio mastering: Ryan Kessler
Transcriptions: Katy Moore


Important background facts or dynamics going on around climate change and our response

Johannes Ackva: I think when people come to climate, it’s a really confusing space, because we’re talking about a century-long problem. We’re talking about four or five uncertain, complex systems levelled on top of each other — like socio-technical systems, the climate system, technology, how emerging economies grow. So there’s a lot of complexity there.

Johannes Ackva: One thing that I find quite useful is to just frame the overall challenge essentially as a competition between two really strong, trajectory-shaping mechanisms.

Johannes Ackva: The first one is innovation and technological change towards low-carbon technology. We’ve seen this with solar, where essentially the investment of Germany and California and a couple of other small countries essentially completely transformed the global picture for solar. This is very trajectory changing, in the sense that there were a couple of countries over a relatively short period of time that fundamentally changed the trajectory of solar over the century — and by that, transformed the emission trajectory of climate quite fundamentally. So that’s one piece, and we’ve seen similar things with electric cars, with wind, et cetera.

Johannes Ackva: The other big mechanism is a little bit competing with that, and that’s carbon lock-in: f you have long-lived assets or infrastructures — stuff like coal plants and steel plants, but also transmission infrastructure for electricity, et cetera — you’re often having investments that will have consequences for decades, and will commit emissions for decades if there isn’t retrofitting, et cetera.

Rob Wiblin: So it’s kind of a race between, on the one hand, clean energy generation is getting cheaper, and on the other hand, we’re kind of pre-committing now to continue using coal and emitting lots of carbon for decades to come — because we’re building all of this infrastructure that will make it in future extremely cheap to continue to do that. And the question is, which of these effects is going to win? And we want to try to help the former and reduce the latter effect?

Johannes Ackva: Yeah, that’s exactly right. And both of these dynamics have this characteristic that they’re like leverage points: they’re kind of moments in time that can have a large impact through time and space. Decisions related to those two are much more important than most other decisions.

Political action versus lifestyle changes

Rob Wiblin: I suppose how I often encountered climate change discussion, at least when I was a teenager or at college, was about changing the amount of emissions that you have by not driving a car or not taking flights. It sounds like you’re not too keen on that as a key focus for advocacy. Why is that?

Johannes Ackva: I mean, that’s also how I grew up. I literally grew up with this idea of like, “I need to save water, because otherwise the water will run out.” It wasn’t climate, but those kinds of things, right? Or like, I never got a driving licence for climate reasons, and all these things. But I think it’s not so much that I’m not a fan of this; I think that, as soon as it only a little bit crowds out your political action, that’s not the thing to focus on. That’s the way I would put it.

Johannes Ackva: So I’m doing a lot of those lifestyle changes myself. But I think ultimately, political action in the broader sense is where essentially everyone listening to this can have more impact. And this can be different things: it can be voting, protesting, writing to your senator. For me, donating is really a form of political action as well.

Johannes Ackva: Ultimately, the reason for that is because your lifestyle changes — even when you’re in the US, which is the highest per capita emitting rich country, and your emissions are something like 10 tonnes per year — can maybe reduce this a little bit. But ultimately, the most you could do is reduce that. And compared to other changes you can induce, this is just not that significant.

Johannes Ackva: And that’s also not how we would solve any other kind of issue. Like, we would not solve crime by saying everyone should just not commit crime, right? That’s part of it, but we’re also having police, and we’re building a public response to this. Just to show that framing matters, I think it’s useful to think about how we think about other problems. And for other kinds of large social problems, we never think we’re solving them by like, billions of people collaborating on virtuous actions every day. This is just not a mode for how we solve other problems.

How to act given climate damage isn't linear

Johannes Ackva: It would seem totally reasonable that the goal is to maximise emission reductions, because that seems like the obvious thing to optimise for. But I think the most clear or robust finding we have on climate damage is that climate damage is very nonlinear in expectation, which means that a world of 3° of warming is much worse than twice as bad as a world of 1.5°, and 6° is much worse than twice as bad as 3°.

Johannes Ackva: The way that economists usually talk about this was saying that the social cost of carbon was different, right? The social cost of carbon was always contingent on a given emissions trajectory. And that means that fundamentally, avoiding a tonne of carbon in a particularly bad future can be orders of magnitude more important than avoiding a tonne of carbon in a very benign future. So it’s this nonlinear damage structure that kind of breaks this at the first instance.

And then where it really becomes action relevant — because right now, it’s fairly academic — is as soon as we think we know something about what correlates with bad futures. So for example, let’s say a climate scientist has said that we’re not in like 4% worlds where renewables have succeeded beyond expectation, right? Those two things do not go together.

So we know that if we’re in a high-damaging future — or we probabilistically know, like we have like evidence that something is very likely — then intermittent renewables must have failed in some way, right? And that tells us something about actions we can take that are particularly valuable in those worlds — for example, investing in other energy sources, such as advanced nuclear, et cetera.

Rob Wiblin: Yeah, I see. So the logic is that each degree of warming is worse than the last — and potentially by quite a large margin, because we’re getting further and further away from what humanity is familiar with, and the change is happening more rapidly. So going from 0° of warming to 1°, maybe humanity can handle that reasonably well in the scheme of things. But going from 5° of warming to 6° is potentially a massive problem. Much, much worse. And so all else equal, you’d much rather reduce a million tonnes of emissions in the hypothetical scenario where we’re at 6° of warming than one where we’re at 1° or 2° of warming.

Rob Wiblin: So for example, with renewables: if it’s the case that solar and wind are just going to smash it out of the park and massively reduce emissions, and we’re just going to electrify transport and use renewables to generate it, if that’s the future scenario that we’re in, then it doesn’t matter so much. Because that means that we’re going to be on a low-emissions trajectory and a low level of climate change. So what you want to do, or one approach you could take, is to try to imagine what the scenarios are where emissions end up being really high, and there’s really high levels of warming, and what we could do to reduce emissions in those cases.

Johannes Ackva: Just to give an analogy from another cause area: for example, if you think about advanced artificial intelligence, and you guess there are some futures where AGI is inherently safe — but that’s certainly not the focus of our efforts to reduce AGI risk, right? That’s kind of the analogous case, where there are certainly worlds, like with renewables we’ve solved intermittency, a lot of these things are easy, et cetera. And we’ve maybe wasted a little bit of money on hedgy climate philanthropy, but we should be very happy about that, because that is much better than the opposite, which is kind of piling on to the mainstream response and not being prepared for failure.

Why we focus so much on specific degree-change targets

Johannes Ackva: I’d guess there’s two forces here. I think one is really the need to reduce uncertainty, or the need to reduce complexity. Because generally, if you entertain like 20 different scenarios, you cannot really act politically. So you need to kind of get a common denominator. I think that’s kind of like, how can you actually make policy work? Or not only policy, but also a wider kind of societal discussion.

Johannes Ackva: And then there’s the other aspect, which is about how climate policy has emerged around setting ambitious targets far in the future. So those targets become very important, and then become broken down politically, essentially as a mechanism of political force. If you follow discussions in high-income countries on climate policies, you will often hear something like, “This country has to reduce emissions by this amount by 2030. Otherwise, we will not meet the Paris Agreement,” or “Otherwise, we will not stabilise temperatures at 1.5°.” Those statements don’t really make sense — those things are calculated from one scenario. But this is kind of the way to structure a political conflict space, and then you can have a debate about whether you want to meet this target or not. But that’s, I think, what’s happening.

Rob Wiblin: You mentioned that it was kind of taboo to think about the 4°, 5°, 6° change scenarios. Why is it taboo to look into that?

Johannes Ackva: Well, for the really high-temperature ones, it’s maybe because they’re just really unlikely, or it’s also hard to do good science on them. But I think the reason it’s taboo is that the climate community — and this includes the climate science community — by and large has the goal to motivate stronger action. And saying we might fail is not a very positive move, right? It kind of always has to be about how we should meet those targets, and we should not already plan for failure in a way.

Johannes Ackva: So I think that’s kind of the mentality. You always want to emphasise the urgency or the absolute importance of those targets, right? I mean, what I mentioned in terms of how the policy debates turn out, like, “The UK needs to meet this target by 2030”: this makes no sense. The UK is less than 1%, and 2030 is only one decade of a century-long challenge. But that’s kind of how it’s broken down in terms of being politicised — how it’s turned into a political action, the political conversation.

Geothermal energy

Rob Wiblin: And as I understand it, there’s kind of two different categories here: there’s the classic geothermal energy, and then there’s this hot rock geothermal, which is where you dig much, much deeper, and you can get sufficiently hot rocks almost everywhere if you’re able to to go down far enough.

Johannes Ackva: Yeah, that’s roughly correct. Classical geothermal is very location specific, and it’s good when you have it, but essentially only available when you have volcanoes with very specific conditions. That’s kind of a niche renewable resource. Groups like Clean Air Task Force or Project InnerSpace work on or are supporting the development of superhot rock, and what you’re looking at is drilling much deeper and then injecting water and getting the heat out. So “geothermal anywhere” is kind of the catchphrase here — making geothermal location-independent — essentially by utilising and further developing technological advances that were brought about by the fracking revolution in the United States. So we now are much better at drilling: let’s use this not for extracting gas, but for getting heat out.

Johannes Ackva: It’s a really promising bet. If this works, you can essentially generate clean, low-carbon electricity that is also firm: that is available 24/7 and that’s relatively energy dense, so you could also do repowering potentially with this. This is very exciting from an energy standpoint, but extremely nascent. I guess because of the connotations with geothermal traditionally it requires active work to change the perception of geothermal and to build the excitement to actually try those. This is another example where philanthropy can be helpful, because it’s not rocket science: one can do those things, but one needs public experimentation. One needs to drill those wells, et cetera — private capital will not do that. So you need to make those more likely, and the way to make this more likely is through targeted advocacy.

Rob Wiblin: What are the reasons why hot rock geothermal is most likely to not work out, and not be a fantastic way of solving this problem?

Johannes Ackva: To me, at least, I think the most likely way it would not work out is if we’re not getting our act together in terms of making it work. Essentially, this requires some progress in material science, it requires experimentation, et cetera. So we want to walk down this technology path and try this out. But this will take a sustained policy effort. This is something that will take a decade and will take significant public investment.

Johannes Ackva: So I think the main uncertainty is like, will this actually happen? Obviously it could also not work technologically. But in general, it seems much lower risk technologically than something like fusion, because ultimately what you’re doing is you’re extending a set of technologies that you’ve already developed for the shale gas revolution and applying it to a new context. So this is kind of innovation, but it’s not rocket science.

The climate footprint of agriculture

Johannes Ackva: This certainly does not receive enough attention. It’s also generally hard to decarbonise for all kinds of different reasons. I think the thing I’m most excited about in this space are alternative proteins as kind of a modular technology that we could scale in a similar way that we scaled other modular technologies through public investment. So that’s something I’m quite excited about there compared to other opportunities, because that could work quite well.

Obviously, we’ll only have effects in the 2030s to 2040s. But to me, that seems all right, because methane emissions right now — on the view that I take — are not that important right now. Not reducing methane this decade, but reducing it in 2030s, there’s less kind of impact cost.

Rob Wiblin: How does working on these hard-to-decarbonise industries interact with the issue of mission hedging and wanting to focus on the worst-case scenarios, the cases where there’s lots of emissions? Is there an interaction there?

Johannes Ackva: There’s definitely interaction there. Pretty much irrespective of what happens, electric cars will replace combustion engines, et cetera. So even in the worlds where international climate policy falls apart, the air pollution arguments alone are sufficient reason to push towards electrification, given where we are right now with costs, et cetera.

I think another prominent interaction there is that “hard-to-decarbonise” is almost always about energy density. Essentially, it’s very strongly correlated with “difficult-to-electrify.” So in that sense, if you think about potential breaking points in the climate response, I think that’s another interaction there.

Rob Wiblin: Yeah, and I suppose, maybe just the obvious one that was occurring to me, but I wasn’t putting my finger on it, is that in the scenarios where we emit a lot more than we expect, those might be worlds where we just never figure out how to decarbonise planes or shipping or concrete production or steel — it turns out to be really hard. And so focusing on finding a way to decarbonise those, where we might just never get on a trajectory of doing so, is more concentrated on the worst worlds, potentially.

Johannes Ackva: That’s exactly right. It’s a disproportionate share of future emissions, in particular in bad worlds.

Articles, books, and other media discussed in the show

Founders Pledge is hiring researchers to join its climate-focused grantmaking programme!

Johannes’s work:

Founders Pledge’s work:

Promising projects and organisations in this space:

Neartermist and longtermist benefits of working on climate change:

Careers advice for roles in climate change mitigation:

Other 80,000 Hours podcast episodes:

Everything else:

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About the show

The 80,000 Hours Podcast features unusually in-depth conversations about the world's most pressing problems and how you can use your career to solve them. We invite guests pursuing a wide range of career paths — from academics and activists to entrepreneurs and policymakers — to analyse the case for and against working on different issues and which approaches are best for solving them.

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

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