Three simple reasons why we think pro-nuclear climate philanthropy should (at least) triple

Major global companies and 31 nations have now committed to a pledge to triple nuclear power by 2050, signaling a recognition of nuclear energy’s role in meeting the world’s rising electricity demand.

Founders Pledge became the first major philanthropic community to join them. This week, our Climate lead Johannes Ackva will speak on a panel at the Nuclear Energy Policy Summit in New York to discuss why we support increasing philanthropy in favor of supporting nuclear power.

Much of our grantmaking through the Climate Fund focuses on investing in underexplored opportunities in the climate philanthropy landscape. We’ve been investing in clean firm power since 2018, allocating over $10M to nuclear efforts via grantees like the Clean Air Task Force, TerraPraxis, WePlanet, Tsinghua University, and Quantified Carbon.

Here are three simple reasons why we see nuclear-focused work as an urgent priority for climate philanthropy.

Reason 1: Neglectedness

A common indicator of the relative promise of fundable opportunities is their neglectedness: how underfunded they are compared to how impactful they could be.

In short, when an opportunity is more neglected, it’s likely that open funding opportunities in that space are more promising because there are low-hanging fruits there to be picked (neglectedness) and because there are few other funders picking those fruits in parallel (additionality).

According to data from ClimateWorks and our own analysis of the pro-nuclear ecosystem, only 0.1-0.2% of climate philanthropy at large¹ supports nuclear energy’s role in climate mitigation. That means for every $1,000 in climate philanthropy, only $1-$2 goes to nuclear energy.

To contextualize this number in a more intuitive way, nuclear energy receives at most 2.5% of climate philanthropy targeting clean electricity.² In other words, less than $1 in every $40 for clean electricity goes to nuclear energy.

This alone doesn't prove nuclear energy is neglected as a philanthropic area. After all, the relative scarcity of pro-nuclear philanthropy could be justified if nuclear philanthropy were unpromising—correctly underfunded rather than genuinely neglected. We believe the underfunding reflects genuine neglect for two reasons.

First, spending time in climate philanthropy reveals that this underfunding generally isn't the result of a rational calculation, but rather stems from traditional environmental discomfort with nuclear energy, in which many foundations and foundation staff are steeped, combined with risk aversion and reputation concerns.

Second, organizations doing pro-nuclear work face more severe funding constraints than we observe in most other climate philanthropy areas. While we can't share specifics publicly, we frequently encounter promising projects that would have ready access to multiple funders if they worked on other issues, yet remain unfunded or dependent on a small set of funders.

While it's impossible to specify the proper share of nuclear-oriented climate philanthropy, it clearly should exceed 2.5% of clean electricity philanthropy. Even a tripling would put nuclear-oriented philanthropy at less than 10%.

Reason 2: Meeting the Moment

If nuclear philanthropy was already a neglected part of climate philanthropy pre-2022, the context has clearly changed since then. Many factors contributed to this shift, beginning with the energy crisis of 2021 and its intensification through Russia’s 2022 invasion of Ukraine, combined with the ongoing rise in electricity demand and its perception as a national security issue in the U.S.

These factors have expanded the Overton window for nuclear advancement. We can observe this in concrete policy changes: the Tripling Nuclear Pledge by governments, increased finance sector engagement, changing nuclear politics in the U.S. and Western Europe, and the World Bank's recent lifting of its nuclear financing ban.

What does this moment mean for climate philanthropy and the civil society ecosystem supporting nuclear expansion? We see two major implications.

More surface area requires more nuclear philanthropy

To understand how changing policy and industry momentum should affect philanthropy’s focus on the same issue, we need a model of philanthropy's role relative to other sources of funding and effort.

As we’ve outlined many times before, we think it’s reasonable to think that the most useful function of philanthropy is not simply to add to existing public and private pools of funding—given that philanthropy is only about 1/200th of the scale of the overall societal climate effort—but rather, to improve the allocation of these much larger pools. This is a well-known function of civil society, both from the history of philanthropy and from the political science literature on topics like “legislative subsidy.”

Viewed through this lens, an expanded Overton Window should motivate increased nuclear philanthropy. Put simply, there’s much more surface area for nuclear-oriented philanthropy to work on now—more policy processes to consult on, more policymakers to brief, and more strategies to develop to ensure that society’s attention to nuclear energy is used productively.

Lower risk justifies more investment

Separately, the dramatically improved environment for nuclear energy also means that the tractability of nuclear-related projects is increasing.

Previously, the lack of expected public support for nuclear-related efforts was often a key reason for pessimism about nuclear projects. Funders don’t need to discount as strongly for lack of nuclear support, so more projects now should meet the funding bar.

For example, now that the World Bank has lifted its nuclear ban, many projects focusing on building nuclear capacity in the Global South have become more attractive propositions, because the lack of financing was previously a strong constraint on expected success.

Reason 3: Robustness

Finally, if there’s one key lesson from the last year, it’s that we shouldn’t take for granted the strength of ambitious left-of-center climate policy, in the U.S. or worldwide.

Climate action needs to be robust to conditions unfavorable to traditional climate progress as a matter of prudent risk management—a principle we’ve always held true, but which has become especially important after last year’s policy changes. We must invest in solutions that don’t require explicit climate motivation and don’t depend on left-of-center support, but rather appeal to multiple political constituencies.

Nuclear energy and philanthropy targeting its acceleration provide exactly such a hedge—an opportunity to make climate progress when explicit climate policy loses support across the Western world.

Translating Analysis into Action

While we add more technical detail when incorporating these considerations into our grantmaking, we wanted to outline these three reasons to explain why we’re excited about increasing philanthropy in support of accelerating nuclear energy.

Our portfolio demonstrates the diversity of high-impact opportunities available to philanthropists ready to engage seriously with nuclear philanthropy:

• We've supported the Clean Air Task Force's groundbreaking work on advanced nuclear policy in the U.S.
• Our funding for WePlanet supports digital-first, pro-nuclear civil society campaigns that reach new audiences beyond traditional environmental constituencies.
• Our grants to TerraPraxis focus on innovation-led approaches to repowering existing infrastructure, turning coal plants into clean firm power assets.
• Our funding for Quantified Carbon targets the massive opportunity to retrofit coal plants in emerging Asia where committed emissions are most concentrated.
• Our grants to Tsinghua University's 3E Institute focus on nuclear repowering research in China, where coal plant retrofitting could dramatically reduce global emissions.

Nuclear energy stands at a historic inflection point, with unprecedented political support, private sector investment, and technological progress converging to create new opportunities. But the philanthropic sector is still lagging behind, while governments and corporations take the lead. Tripling funding wouldn’t make nuclear the center of climate philanthropy—but it would bring it closer to its rightful place in the mix.

Philanthropy has a rare chance to shape the future of clean firm power before the window narrows again. By stepping up now, we can ensure nuclear energy becomes not just a temporary priority, but a real pillar of global decarbonization.

Notes

1. From ClimateWorks (2024) on 2023: $9.3–15.8B. Presumably climate philanthropy has grown slightly in 2024 and fallen a bit in 2025, with $15B seeming realistic on the upper end, though my best guess would be closer to $13B. Advanced nuclear philanthropy in 2022/2023 is estimated at $5-10M based on allocations from Breakthrough Institute (20-40% of their effort), Third Way Clean Energy Program (20-50% of clean energy program), Good Energy Collective (100% of their effort), CATF (10-25% of their US-focused effort), and ClearPath (10-25% of their effort). Funding amounts are sourced from organizations' annual IRS 990s. By 2025, new entrants into the space such as NSI with a $5M budget, plus increased activity from right-of-center climate and clean energy organizations that sometimes include nuclear programs, bring estimates to $10-20M, which results in 0.1-0.2% of climate philanthropy at large. ↩

2. According to ClimateWorks (2024), global foundation funding to clean electricity totals $384.8M average annually between 2019-2023. To estimate total philanthropy including individual giving, we apply multipliers that account for individual giving typically doubling or tripling foundation totals (also see ClimateWorks (2022), the numbers for individual giving are much more uncertain). Using a low multiplier scenario of $5B individual philanthropy yields a multiplier of 2.04x, while a high multiplier scenario of $11B individual philanthropy yields 3.29x. Applying these multipliers to clean electricity foundation funding we get a range of $785M-1,266M for total clean electricity philanthropy globally. With nuclear estimated at $20M/year on the high end, this means nuclear represents at most ~2.5% of philanthropy targeting clean electricity. ↩