Matthew, thank you for engaging critically with our work. We weren't contacted for comment before publication, which led to some mischaracterizations of our strategy as well as the case for nuclear-oriented climate philanthropy. The TLDR for everyone who stops reading here is that I think – while it cites a long of specific things I agree with – Matthew’s post: 

(a) misunderstands the actual foci of our work, 
(b) makes a set of claims against nuclear that are much weaker than they seem and, crucially,
(c) does not address and thus does not refute the positive case for nuclear-focused climate philanthropy – nothing Matthew observes refutes the case for nuclear-oriented climate philanthropy.

(a) Misunderstanding of the actual foci of our work

Reading the statistics one could get the sense that almost half of our work is nuclear-specific (17-46%).

The high share here largely comes from an expansive definition of “nuclear-adjacent” and treating “nuclear-adjacent” grants as fully counting towards nuclear.

Indeed, when I replicate and expand the analysis, I actually get a higher share of “nuclear + nuclear-adjacent” grants: 50%. However, I also get 49% for advanced geothermal and I even get ~15% for technologies we never made a specific grant in (LDES).

The point is that “adjacency” is not a good metric to think about our grantmaking at this point given that most of what we have been doing over the past several years have been technology-agnostic or multi-technology bets. Over the last two years (2024 and 2025) we made one grant only focused on nuclear (WePlanet), everything else we did that was nuclear-inclusive was equally geothermal-inclusive (e.g. coal repowering). What is more, most of our focus has been on defending and improving the effectiveness of the climate policy architectures under attack; benefitting all technologies in need of climate policy support (crucially, inclusive of many renewables). 

The analysis only uses grant data through May 2025. Our full 2025 grantmaking, which is not yet reflected, shows the full picture even more clearly.  The vast majority of our grantmaking are efforts to improve the resilience and efficiency of climate policy architectures that are under attack everywhere and that negatively affect many technologies, including renewables. 

As I am writing this, I am finishing a set of grants on defending European climate policy – if technology-specific at all, then mostly benefiting geothermal (a specific grant) and industrial decarbonization (green steel, green hydrogen, etc.) – as well as a grant on US innovation policy that will be adjacent to nuclear, but also all other technologies this and the next Administration are interested in pursuing with the DOE.

In short: yes, we support nuclear but we also support other philanthropically neglected technologies (geothermal, industrial decarbonization) and also – more crucially – most of what we fund these days does not map onto single technologies to begin with.

(b) The linked essay contains a lot of specific claims, even many I agree with, but overall reads more like a collection of anti-nuclear arguments than an engagement with our philanthropic strategy.

In particular:

1. Nuclear v renewables
The essay starts with making the point that in a marginal least-cost electricity market in the US nuclear will, under most assumptions, not win against renewables.  

This is probably true, but it is somewhat irrelevant to the question of whether nuclear-oriented philanthropy is high-impact because most of the world does not make energy policy decisions in this market structure, and indeed the countries we should care about most from a global emissions standpoint – China and India – are both either actively building more nuclear (China) or are actively preparing for it (India). These are the countries that matter most for cumulative emissions, and the economics, politics, and policy are very different than in the US. 

Bottom line: US market dynamics are essentially irrelevant in evaluating global decarbonization bets.

2. The value of clean firm power
The essay then goes on to argue that the value of clean firm power – the broader category to which nuclear belongs to – is very limited because most increase in population and energy demand will come from near-equatorial regions which can do great with renewables + storage.

Last I checked, China alone was 35% of future emissions, Europe and the US would be another 10-15% and these would not be the only regions with strong seasonality. So even if one fully bought “clean firm power doesn’t matter outside regions with strong seasonality”, this would be at most a 2x discount on nuclear. Even with generous assumptions, 50%+ of future emissions will still come from regions with high seasonality.

Bottom line: Unless you believe decarbonization in the US, EU, China and other regions with high seasonality is automatic, clean firm power matters.

3. The unexplained costliness of nuclear power
One of the key disagreements with the essay is the unexplained nature of cost increases, this is one of the two most relevant cruxes.

The essay cites a study that identifies low labor productivity as the main driver of expensive nuclear power in the West, but fails to ask where this low labor productivity comes from.

It seems clear to us that the poor economics of nuclear power in most Western countries are not independent of societal factors, i.e. low labor productivity is the result of the nuclear supply chain having atrophied/collapsed. This is widely acknowledged in the literature, including by the National Academies and DOE reports that Matthew himself cites.  No one claims that the West right now is set up to build cost-efficient large reactors at scale.

The real question is whether the conditions that made nuclear power expensive are fixed features of the technology or contingent outcomes of policy choices. Historical examples from the West and current examples from China point strongly toward the latter–that  societal conditions, rather than techno-economics alone, are the decisive influences on the economic viability of nuclear power. 

This makes it especially strange to argue that philanthropy and civil society can play no role; after all, we know that factors such as public support, market structures, regulation, and similar factors could make a large difference and that they have been different in the past.

What is more, we should not lose the eyes on the ball here – whether or not the West gets its act together on building nuclear power is not the decisive question to evaluate nuclear philanthropy, especially not globally focused nuclear philanthropy of the type we are doing.

4. The assumed but unjustified low tractability of nuclear power
Matthew writes on tractability:

“Assuming that eventually new nuclear generation can be built and displace gas, advocacy work still needs to be effective to be justified. Advocacy work could fail to cause additional government support, or the government support could fail to lead to more development. As we saw in part 2, the main challenge for nuclear power is cost. The cost problem is largely due to nuclear power’s nature as a massive infrastructure project with long construction times. Efforts that seek to gain public support are useless, because they have little bearing on project costs. Efforts for regulatory reform and easing licensing have limited impact, because regulatory burden accounts for a small component of the total project cost. Further R&D is unlikely to be effective at reducing costs. The U.S. DOE has been funding basic nuclear R&D since the 1950s and has little to show beyond the large light water reactors of the existing fleet. The plethora of new designs, including SMRs (although most aren’t small), haven’t been able to find a design with better economics. The range of effective advocacy is likely limited to streamlining acceptance and financing support for one large, replicable design, as done in China and South Korea.”
 

(The focus on gas shows the US bias of much of the analysis, in many parts of the world it would be coal that would be replaced)

Together with stating the unaffectability of the economics of nuclear power, if one buys this then – yes, indeed! – one can only conclude that nuclear-oriented climate philanthropy is not worth doing.
 

But this section – which would need to be at the heart of a critique of nuclear-oriented philanthropy – makes very strong claims of intractability on essentially no evidence. 
I think one would need much stronger evidence to believe that the situation of nuclear energy in the West is (i) inherently unaffectable and, more importantly, (ii) that this unaffectability translates to those regions most decisive for future decarbonization.

Essentially, we are to believe that nuclear-oriented philanthropy is fundamentally less tractable than many other things we – as a community – are happy to fund. And we are to believe that in a situation where nuclear has more momentum than it has had for 20 years, a very small philanthropic effort – $10-20M/year – can have no significant impact on how well this effort translates into outcomes.

Concretely, over the past decade and a half we've seen a small civil society effort contribute to meaningful shifts in the political economy of nuclear — from the bipartisan ADVANCE Act streamlining NRC licensing, to the COP28 declaration to triple nuclear capacity signed by over 20 countries, to shifting public opinion. 

Obviously, these aren’t fully caused by civil society – many other factors contributed – and obviously these aren't sufficient to solve the cost problem alone, but they put strong doubts on the claim that the trajectory of nuclear energy is unaffectable by advocacy.

I think the baseline view on the tractability of nuclear-oriented work should be that it is, indeed, somewhat more challenging than working on more popular technologies, but it is strange to think that there is anything close to prohibitive evidence against the tractability of nuclear-focused work, a list as the above one could be written for many technologies.

(c) The positive case for nuclear-oriented philanthropy does not rest on any claim Matthew refutes.
Despite being German, my mantra is not “nuclear uber alles”. 

I agree with Matthew that nuclear power is not a least-cost marginal option in the US right now and also that nuclear power has a lot of challenges I am not sure it will overcome. Like Matthew, I also believe that renewables will play a large role in future power decarbonization and I also believe that nuclear is just one bet – among many – that are worth supporting. Indeed, at FP we support geothermal as much as nuclear.

For this reason, nuclear is far from the only thing we fund and even the ~17% estimate is vastly overestimating our current share of nuclear-funding given what I discussed above.

All that said, there is a positive case for nuclear-oriented philanthropy and I think it’s important to state it as it is somewhat unrelated to Matthew’s arguments.

The core of our case is this:

1. Nuclear could be cheap: There is nothing inherent about nuclear being expensive, nuclear being expensive is – in some sense – a policy choice. We know this because we were able to build nuclear quickly at scale in the past and some world regions are still able to do so.
    
2. Nuclear being cheap would be very desirable: Most emissions to avoid are not in the tropics; indeed, if it is true that tropical countries will automatically do solar + storage then this is a reason to not focus there. Nuclear is one of a few clean firm power bets and this is what fundamentally motivates its value (e.g. I would agree with a critique of only funding nuclear and not funding geothermal).
3. The argument for clean firm power is partially about hedging: While the essay states the point about hedging, it doesn’t make the argument explicit. The reason we should expect clean firm power to be positively correlated with climate damage, i.e. disproportionately useful, is because many of the conditions that might constrain renewables – limits to grid build-outs, limits to progress in seasonal storage, increased demand for energy-dense sources, difficulty of retiring coal plants etc. – are not applicable to clean firm power, increasing expected clean firm power deployments in those worlds where it matters most.
4. Philanthropy does something the private sector can’t and nuclear-oriented philanthropy is neglected: Just like other energy industries, nuclear does have a lobby – nothing special about this – but if one assumed no technology with a lobby could profit from a philanthropic effort then most climate philanthropy would be moot. Philanthropy can enable things that private special interest can’t.
5. The trajectory of nuclear energy policy and nuclear power is in flux: Clearly, we are seeing a lot of dynamism in the nuclear space right now, with many changes in policy, politics, and investment decisions. It would be strange to assume nothing can be affected.
6. What we see nuclear-oriented grantees achieve is in line with expectations: What we observe as the outcomes from nuclear-oriented grantees does not justify claims of the fate of nuclear energy being unaffectable – indeed, it seems a small civil society effort on nuclear had at least some impact on the changing politics of nuclear we’ve seen over the past 15 years.

Overall, these are the qualitative arguments that compel me to see nuclear-oriented grants as one component of a grantmaking strategy aimed at minimizing expected climate damage. 

In a situation such as nuclear – where many inside-view arguments are heavily contested – one should not believe that chaining a set of anti-nuclear arguments together makes a compelling case against nuclear, just like the opposite affirmative case shouldn’t just be based on a set of pro-nuclear arguments. 

One needs to look at the expert views in aggregate, understand where they come from, and try to identify what the most robust stylized facts are. When it comes to nuclear, there is a wide distribution of views on the role of nuclear power in global decarbonization – from Matthew's position that nuclear has minimal value to considerably more bullish assessments from bodies like the IEA, IPCC, and multiple national academies. Climate philanthropy as a whole, however, puts almost no weight on the more bullish end of that distribution.

And we know that this is not random. The environmental philanthropic sector has well-documented institutional roots in the anti-nuclear movement, and there are strong conformity pressures in philanthropic communities — as this very debate illustrates, supporting nuclear is reputationally costly in ways that supporting solar or efficiency simply isn't. These are exactly the conditions under which EA reasoning suggests a cause area is likely underfunded relative to its merits: a wide range of expert views and strong neglectedness driven by sociological factors rather than a considered analysis of relative impact.

This is, after all, the same logic that led effective altruists to take seriously neglected tropical diseases (overlooked for reasons of geographical neglect), farmed animal welfare (speciesism), and catastrophic risks (small probabilities) that fell outside mainstream philanthropic discourse and where the strongest case for outsized marginal impact comes from a consideration of moral and cognitive biases shaping philanthropy at large.

Working on climate with an interest in AI, I found this a fascinating read.

But I am a bit left wanting as to what the learnable lessons for the AI community are that will make the AI community act better than the climate community.

Could you articulate this?

(I think a lot of the parallels you cite are true, but I don't think they offer a lot of actionable implications, they feel more like negative updates on the difficulty of acting wisely for fast-moving coordination problems with deep uncertainty and lots of politicization).

What I’m reacting to is more the “hot take” version that shows up in EA-adjacent podcasts — often as an analogy when people talk about AI policy: “look at nuclear, it got over-regulated and basically died, so don’t do that to AI.” In that context it’s not argued carefully, it’s just used as a rhetorical example, and (to me) it’s a pretty lossy / misleading compression of what’s going on.

I agree it's a bit lossy and sometimes reflexive (this is what I meant with relying on libertarian priors), but I am still confused about your argument.

Because the argument you criticize is an historical one ("nuclear over regulation killed nuclear") which is different from "now we need many steps and there are different strategies to make nuclear more competitive again".

I think it is basically correct that over-regulation played a huge part in making nuclear uncompetitive and I don't think that Isabelle or others knowing the history of nuclear energy would disagree with that, even if it might be a bit overglossed / stylized (obviously, it is not the only thing).

Out of curiosity: Where have EAs argued that "nuclear is overregulated" and, more specifically, where have EAs argued that over-regulation is the only or dominant driver of the cost problem?

It's probably true that this sometimes happens -- especially when EAs outside of climate/energy point to "nuclear is overregulated" as something in line with libertarian / abundance-y priors -- but I think those in EA that have done work on nuclear would not subscribe to or spread the view that regulation is the only driver of nuclear problem.

That said, it seems clearly true -- and I do think Isabelle agrees with that -- that regulatory reform is a necessary component of making nuclear in the West buildable at scale again (alongside many other factors, such as sustained political will, technological progress, re-established supply chains, valuing clean firm power for its attributes, etc).

Is it really?

Thanks Vasco!

I agree that social dilemmata are not, by and large, solved through individuals spontaneously acting differently in isolation.

I think a fairer title of the piece could have been "economics needs more progress studies and more social science" given the vast differences in how well societies across time and space are solving coordination problems mediated (if not explained) by differences in institutions, norms, laws, etc.

The basic functioning of society -- the most important coordination problem of all -- varies widely across locales with the same technology.

Is there any justification of the "most"?

It's easy to list many social dilemmata that have been transformed by technology, but it would probably be equally easy to come up with a list of social dilemmata that are primarily solved through non-technological means, first and foremost through social norms and laws successfully solving similar problems.

Thanks for the thorough reply!

What's the upshot of this? Do you see this as informing relative prioritization between the two causes?

This is a great post!

I wish there was more discussion like this and more appreciation for how challenging the current moment is, I think this would bring EA closer -- in a good way -- to where a lot of people concerned about the world are.