Further Reflections on the National Academies Report on Solar Geoengineering: A Response to Stephens et al

‘The Dangers of Mainstreaming Solar Geoengineering’ offers observations about the necessity of international cooperation and public engagement in solar geoengineering (SG) research, as well as the urgency of prioritizing efforts to reduce greenhouse gas emissions. Indeed, these points are foundational to the analysis and recommendations of Reflecting Sunlight, the National Academies of Science, Engineering and Medicine (NASEM) report critiqued in the article.

Readers of the article might nevertheless come away with mistaken impressions of the NASEM report’s key points. We served as members of the committee that authored the report. In light of the article’s critique, we offer in our individual capacities our thoughts on the report, its recommendations, and role.

The Reflecting Sunlight report envisions research on a diverse array of issues relevant to policymakers who may make decisions about SG (NASEM 2021, rec. 6.1). Recognizing the complexity and multi-dimensionality of the topic, the report recommends a transdisciplinary and socially responsive approach to research. In addition to the technical feasibility, impacts, and physical science dimensions of SG, research should consider environmental and societal impacts as well as methods for detecting SG deployment (pp. 14–15). Moreover, as a priority focus, the research inquiry should examine the context and goals of SG research. Important areas to explore include clarifying the possible goals of an SG program, understanding how such goals might shape research priorities, exploring the future conditions under which decisions on SG may occur, and identifying ways to build countries’ capacity to engage meaningfully in research and research governance (pp. 13, 15). Research should also examine social dimensions, including how to engage various publics and stakeholders in SG research decisions and how to integrate ethics, justice, and equity considerations (p. 14).

The broad, transdisciplinary research program envisioned by the report should be coordinated with other countries and be subject to robust governance. The recommended research program would prioritize co-development of research with other countries and incorporate engagement from civil society and key stakeholders, including climate vulnerable communities and underrepresented groups around the world (rec. 4.1). As the report recognizes, research governance and research activities must evolve ‘hand-in-hand, with ongoing mechanisms for stakeholder engagement and input’ (p. 7).

Stephens et al. suggest – incorrectly – that the report treats public engagement ‘as an instrument to promote solar geoengineering activities’ (Stephens et al. 2021, p. 5). To the contrary, the report emphasizes the substantive role of public and stakeholder engagement in assessing and shaping SG research. For example, the report recommends a program in which stakeholder engagement is interwoven with program design, development, and assessment, noting that the program should be refined by ‘expanding engagement with stakeholders around the world to help fill gaps in understanding and perspective’ (NASEM 2021, p. 8). The report stresses that engagement should be inclusive and equitable (rec. 4.2, p.10), and it underlines the importance of ‘develop[ing] mechanisms for meaningful representative input regarding whether and how research proceeds’ (p. 178).

The report also offers specific recommendations for institutionalizing engagement processes. To take one example, the report identifies a role for the U.S. Global Change Research Program (USGCRP) in ‘advancing opportunities for meaningful public engagement within and beyond the United States and pathways for this engagement to help inform and shape the research program’ (rec. 4.2, p. 10). What’s more, the report recommends that engagement processes themselves be developed and refined through public and stakeholder participation, additional research, and reflection on the strengths and limitations of past and ongoing engagement efforts (p. 179). Thus, the report does not presuppose a single approach to engagement, nor does it frame engagement as a way to advance a predetermined research agenda. Instead, the report emphasizes the importance of substantive, ongoing engagement, and it counsels that engagement processes be developed and refined iteratively, in conversations with diverse publics and stakeholders.

Contrary to representations by Stephens et al., the NASEM report does not advocate a unilateral U.S. research program on SG. Rather, it calls on the U.S. federal government to establish a research program in coordination with other countries, prioritizing, from the outset, international coordination and co-development of research (rec. 4.1). A national research program should connect to and coordinate with SG research programs and activities outside the U.S. federal government. We acknowledge that coordination falls along a spectrum, and that the report leaves open with whom and to what extent coordination should be undertaken. It is worth noting, however, that the report does highlight the importance of greater engagement with countries in the Global South, suggesting that coordination not be limited to countries where the majority of SG research is already taking place.

With respect to research governance, the report underscores the importance of international cooperation and governance, whether through UN bodies or other international entities, funders, science agencies, and state and nonstate actors (recs. 5.1o-5.1v). Formal international governance of SG research is important, but the report does not recommend that it be a prerequisite to a research program. Acknowledging the difficulty of generating the consensus typically needed for international agreements, and recognizing that multilateral consensus processes can produce relatively weak initial agreements, the report offers governance recommendations that should be adopted at subnational, national, and international levels (Ch. 5).

The report also offers general guidelines for shaping an SG research budget, emphasizing that SG research funding should not shift the focus from other global climate change research and must be accompanied by support for research governance and public engagement (p. 251). The report ultimately suggests ‘a reasonable initial investment in SG research … in the range of $100-$200 million total over 5 years’ (p. 17). These figures are intended to offer a sense of the funding needed to support the recommended research effort, not to provide a ‘detailed budget estimate’ (p. 251). Both the suggested funding range and the report in general aim to initiate an open public discussion on SG research and the future of SG.

As Stephens et al. note, there are risks associated with SG research. The NASEM report recommends a transdisciplinary research program, developed in coordination with other countries, that explores the complex social, legal, ethical, and technical dimensions of SG, and it suggests that – with appropriate oversight, governance, public engagement, and exit ramps for SG research – these risks may be reduced. In accordance with NASEM policies designed to avoid political interference, the committee’s deliberations were confidential. However, the committee prepared the report after soliciting input from stakeholders and the public and holding a series of public information-gathering sessions (pp. 28–29). It is our hope that the report further opens up public discussions about the risks and uncertainties associated with SG, and we welcome perspectives that explore, diverge from, and challenge those expressed in the report as part of a critical dialogue about whether and how research on SG should be further pursued.

Disclosure statement

No potential conflict of interest was reported by the author(s).