How to address solar geoengineering’s transparency problem

In 2010, climate scientists gathered at the Asilomar Conference Center in California, in a convening that echoed a legendary 1975 meeting in which a scientific committee came together in a exercise of self-governance to create guidelines for recombinant DNA, which many at the time feared could have unintended negative impacts on the environment and possibly on human health. The climate scientists 15 years ago had a similar ethical challenge: to provide research principles for solar geoengineering. They realized that the idea of deliberately reflecting a small fraction of incoming sunlight to cool Earth would require higher levels of trust and governance than other kinds of climate research. Climate journalist Jeff Goodell, who attended the 2010 meeting, noted that he may have “witnessed the birth of something new—call it the conscience of a geoengineer” (1).

It’s important that decision-makers and members of the general public know whether geoengineering research is legitimate—meaning the findings are robust, contrary results aren’t hidden, and investigations are free from conflicts of interest. Image credit: Shutterstock/isilterzioglu.

Despite the consensus of the scholarly literature (see SI Appendix, Table S1 for a summary of the numerous discussions on principles and codes of conduct in geoengineering), there are still no established practices around transparency, let alone regulations demanding it. Rather, we have the opposite: private companies such as Make Sunsets, a US-based company that sells “cooling credits” and has been releasing toxic sulfur balloons (2) since 2022, or Stardust, the Israeli startup with $15 million of venture capital funding (3). Few seem to know quite what they are doing. What happened to the conscience of the geoengineer?

Decision-makers and members of the general public need to know that geoengineering research is legitimate, which means that findings are robust, contrary results aren’t hidden, and investigations are free from conflicts of interest. This applies as much to “outdoor” research as it does to modeling and laboratory work, where the idea of geoengineering is shaped. If people are going to evaluate whether to support research or even deployment, they want to know where the idea came from, who funded it, and who was or wasn’t at the table. This is how trust is built.

Transparency Problem

The lack of transparency is, in large part, due to a decision by most governments not to fund and regulate coordinated, non-defense-sector-led solar geoengineering research. Private funding is moving to fill the gap via venture capitalists, foundations that identify niches in the climate philanthropy landscape, or wealthy individuals concerned about climate change who believe they have the capacity and authority to act. Over the period 2008–2018, Bill Gates and his affiliated foundations funded 12% of global solar geoengineering research (4). The Simons Foundation, founded by a billionaire hedge fund manager, is awarding $50 million for scientific research (5), nearly half the total value recommended by the US National Academies in a 2021 report (6). The National Academies recommended an integrated program of research on the context and goals for solar geoengineering research, impacts, technical dimensions, and social dimensions with funding levels of $100 million to $200 million over five years (6). The Quadrature Climate Foundation has also pledged $40 million, thus far largely to physical science research (7). Other high-net-worth individuals, such as Sam Altman, have signaled interest and are offering public commentary on how the field should evolve. The magazine Inside Philanthropy named solar geoengineering the “Biggest Philanthropic Hail Mary” in its 2023 year-end report (8). Tech investor and billionaire Chris Sacca recently stated: “We have no opportunity for survival on this planet unless you reflect back sunlight” (9). This is a clear example of a major funder with a preference as to what the outcomes of solar geoengineering research should be.

This is a dangerous situation. A patchwork of privately funded efforts will decide who is funded, with the risk that expertise gathers in a few elite institutions that happen to be connected to funders.

This is a dangerous situation. A patchwork of privately funded efforts will decide who is funded, with the risk that expertise gathers in a few elite institutions that happen to be connected to funders. Disparate private efforts will also shape what is researched and discussed and, critically, what is not discussed. For example, the Simons Foundation states that social science is out of scope (5), meaning that social and ethical considerations will continue to not be addressed as part and parcel of these grants.

Importantly, private research lacks oversight by the public, meaning that unacceptable risks may be ignored or suppressed in the name of preferred outcomes or profit. There are numerous historical examples, including fossil fuels, “forever” chemicals, tobacco, and pharmaceuticals. Although many scientists may be reluctant to publish unfavorable results, regardless of funding sources, private funding can encourage a perverse incentive structure, whereby the funder can decide whether to publish unfavorable results or take what the National Academies report (6) termed “exit ramps”—criteria and protocols for terminating research programs. This could profoundly harm the public’s trust and ability to make informed judgments. (See also https://www.pnas.org/doi/10.1073/pnas.2118379119.)

The failure of some private funders and researchers to operationalize transparency has made it an empty talking point. But there is still an opportunity for scientists, funders, civil society, and policymakers to act. Here, we propose concrete steps to advance both transparency of funding and transparency of action.

Funding the Right Way

Transparency of funding has some well-established frameworks. University and federal researchers have laws and norms around transparency of funding, including disclosure of conflicts of interest, acknowledgment of funding in publications, training on conflicts of interest, and publicly searchable funding information. Nevertheless, these existing frameworks have proven to be inadequate for bolstering transparency of funding in solar geoengineering.

One major reason is the lack of requirements about funding disclosures for nonprofits—the organizations that happen to be the most prominent institutions in solar geoengineering today. Many are funding research through regranting and are creating governance precedents, both intentionally and unintentionally. This includes deciding what to publicly share, when, and with whom. While many organizations working in geoengineering disclose funding even when it is not formally required, the list of funders is often incomplete, creating a fragmented or fake picture of what they are pushing for.

Even if nonprofits closely mimicked public disclosure practices, the information gleaned would not necessarily be insightful because of nontransparent pass-through philanthropic funding. In the United States, over 41 cents of a donated dollar goes through an intermediary, with 27 cents going to a donor-advised fund (DAF) (10). Donors can make irrevocable contributions to a personal DAF account managed by a sponsoring organization, such as a large commercial investment management firm. They achieve returns on investments, tax benefits, lower reporting requirements, and the ability to advise how the money is spent, all while retaining anonymity. Philanthropy scholars and watchdogs have flagged DAFs as an issue for some time: in 2010, a quarter of the donations for the anti-climate-change lobby in the United States came from a single DAF (11).

Clear and Candid

Transparency of funding is necessary to achieve trust, but insufficient on its own. It must be accompanied by a transparent reporting of the organization’s activities to understand what it’s doing and with whom it’s engaging. This applies to researchers, companies, and nonprofits alike.

In a field as controversial and rife with misinformation as solar geoengineering, a lack of transparency can lead to serious problems. One classic example occurred in 2012 when the Stratospheric Particle Injection for Climate Engineering (SPICE) Project in the United Kingdom was canceled because of concerns about financial gain from patent applications that were initially withheld by the researchers. A more recent example occurred in June 2024, when the city of Alameda, California, canceled the first outdoor solar geoengineering experiment in the United States. According to reports, city officials were concerned by the project’s lack of transparency (12). This mode of “guerrilla science” is antithetical to informed decision-making and negatively shapes how solar geoengineering is perceived. Nevertheless, these secret practices could be the norm for solar geoengineering research without active efforts toward transparency in action. In other fields, it is normal to have research guided by principles; for example, laws and funder regulations about work on human subjects originated from the ethical principles and guidelines in the Belmont Report (13).

Vital Reforms

Governments, funders, and researchers need to act on the existing 15 years of recommendations from scientific and governance expert communities and scientific organizations (SI Appendix, Table S1). They should set up an international research registry (14)^* that establishes community standards, thus encouraging researchers to self-disclose their solar geoengineering activities. These past recommendations also encourage data transparency, including platforms for making data available and accessible to whoever wants it, consistent with increasingly common science practices (15).

If a collaborative effort toward a research registry continues to stall, there are still ways that individual researchers and organizations can make progress. We recommend three simple things as initial steps for solar geoengineering research transparency. These, we believe, are minimum requirements (Table 1); researchers and organizations are encouraged to take additional steps toward transparency.

Table 1.

Potential minimum requirements for transparency in activities across different sectors

Sector	Minimum transparency of activity requirement
Academia	Mirror NSF guidance as a basic ask: a project summary, intellectual merit, statement of broader impacts, period of performance, and disclosure of amount funded (to and from whom) posted in a public, searchable repository.
Nonprofit	Commit to transparency in government engagement, lobbying, advocacy, or any other synonymous term that mirrors the guidance provided by the European Union: who, when, and why. For example, disclosures of meetings would include why the meeting was held, when, and who was in attendance.
Funders	Disclose who they are funding, where the funding comes from (original sources if the funder is a regranter), and what those grantees are funded to do. Or, in the case of fundraising and/or yet-to-be-allocated funding, disclose for what purpose the money is being raised and the desired scope of work.

First, researchers and organizations should pledge to publicly disclose all funding sources and amounts. If accepting private money, they should disclose the original donor and, if applicable, the DAF or publicly state that such information is not known. Furthermore, organizations that regrant (receive funds from donors and then grant those funds to other to researchers, organizations, or individuals) should disclose the recipients and amounts of their funding because the status quo is that those parties might not even know where the funds originally came from. There should also be a public list of researchers, funders (including DAFs), and organizations that take the pledge. Organizations should consider not accepting anonymous funding or developing rubrics for organizations from whom they will or will not accept money (16).

Second, researchers, universities, nongovernmental organizations (NGOs), and funders who undertake research or work in this space should commit to transparency of action by publishing a record of their activities. This does not mean reporting every conversation or simulation; the idea is not to burden information gathering by newcomers in the field or to publicly broadcast every hypothesis exploration. This record is for activities that cross a threshold of action, such as a workshop that is intended to develop a research agenda or other outcome, or advocating with governments around outcomes for or against solar geoengineering research or deployment (see Table 1 for some suggestions). We argue that aspiring to transparency means that there should be a publicly posted record of engagements designed to affect real-world action. We realize that this is presently ill defined. Specific guidance for researchers, NGOs, and funders for how and where such disclosure occurs will require further deliberation, ideally by an independent body through a participatory process.

Third, editors and publishers should require that pass-through foundations specify the individual sources of funding for peer-reviewed articles. Journals have a special gatekeeping role in science and already have established policies requiring disclosure of funding. If funding disclosures in publications are not actually disclosing the source, these policies are not working in practice.

Some of these ideas may seem burdensome for organizations and researchers, making stakeholders hesitant to act. But consider such a response from the public’s point of view. Understanding the funding sources could, in some cases, help the public understand the motivations behind the work and the conditions under which the knowledge was produced. Why should any actor have social license for activities that could end up changing the amount of sunlight coming down to earth if they can’t even change their practices to disclose a funding source? Compared to the scale of action implied by the potential of actually conducting solar geoengineering, these recommendations are a trivial lift.

Clarifying these rules and reporting structures will be necessary for journals, funders, civil society organizations, and universities. But the process can begin with initial voluntary buy-in by members of the community. Confronting climate change is asking the public to make massive changes in how they get around; how their homes, schools, and offices are powered; the food they eat; and many cultural traditions. They need to see that the scientific establishments and organizations that are apparently endorsing these changes are willing to shift their cultural norms and practices, too. The conscience of a geoengineer may have been sparked a decade and a half ago, but thoughts have not translated into action when it comes to transparent practices. That needs to change.

Supplementary Material

Appendix 01 (PDF)