Solar Radiation Management (SRM) is a set of proposed technologies intended to reflect a small portion of the sun’s light back into space to temporarily cool the planet. These envisioned technologies include stratospheric aerosol injection (SAI) and marine cloud brightening, among others. SRM technology was inspired by the cooling effect from the 1991 eruption of Mount Pinatubo in the Philippines, where volcanic particles released into the stratosphere acted as a solar shield, reflecting a portion of the sun’s rays back into space, and cooling the earth nearly 1°F over the following year. Proponents argue that these emerging techniques could lower global temperatures long enough to allow nations to implement other long-term solutions to climate change, thereby helping to save lives and the planet. However, critics warn that SRM may pose serious environmental and political risks if not properly managed.
The potential impacts of SRM raise important questions: who should decide whether to deploy these technologies, and how can it be done responsibly? Should SRM be applied simultaneously across the globe, or in specific regions at different times? Should these decisions rest with international organizations, individual countries, or corporations? What are the risks of using SRM, or deciding not to use SRM?
In spring 2025, the American Academy of Arts and Sciences convened a virtual roundtable to address these questions and more. The event continues the Academy’s previous work on climate and security, including a spring 2024 workshop. The April roundtable brought together environmental and atmospheric scientists, political scientists, and policy experts to explore the potential challenges and opportunities associated with governing Solar Radiation Management. While SRM remains controversial, the urgency of the climate crisis and SRM’s potential impacts warrants continued informed, interdisciplinary, and inclusive engagement on the topic.
The roundtable featured remarks by Chris Field (Stanford University), who recently cochaired the Academy’s Climate Project. His comments drew on the project commission’s final report, which emphasized bipartisan strategies for climate adaptation and mitigation that will remain viable amid shifting government priorities. The discussion was chaired by Tanisha Fazal (University of Minnesota) and also included remarks from Peter Frumhoff (Harvard University), Sikina Jinnah (University of California, Santa Cruz), and Frank Keutsch (Harvard University).
Speakers highlighted SRM’s major governance challenges, including the growing role of private actors in implementing SRM technologies, increasing political polarization—illustrated by recent state-level bans in the U.S.—and a glaring lack of international coordination. They emphasized the need for greater transparency, inclusive decision-making processes, and meaningful inclusion of indigenous peoples and communities in the Global South in decision-making processes related to SRM governance and implementation.
Ethical Questions
While some are optimistic about SRM’s potential to cool the planet, others are concerned that irresponsible deployment could have devastating impacts on the planet and all life that inhabits it. Some roundtable participants also expressed concern for the moral hazard associated with SRM—that it is a climate change band-aid that will dissuade mitigation efforts and absolve the top polluters of responsibility. Speakers and discussants examined the current state and potential future of SRM research and implementation to better understand SRM’s governance gaps, particularly around SAI deployment.
Governance Questions
Many participants called for the development of enforceable international frameworks that could regulate SRM deployment. Without clear, binding agreements, they emphasized that unilateral or uncoordinated use of SRM by academics, governments, or private companies could be disastrous. Some fear that uncoordinated use could ignite or exacerbate geopolitical tensions and worsen global inequity and environmental instability.
Participants emphasized that any governing framework should be rooted in transparency, scientific research, and equity, and that efforts should not be solely led by a handful of powerful nations or private actors. They stressed the importance of including mechanisms for accountability, dispute resolution, and environmental monitoring in any formal agreement. While there was no consensus on exactly what constitutes a successful agreement, many suggested that governance should first be developed at the national level and then expanded through bilateral agreements, rather than launching a sweeping multinational treaty.
Public Perceptions and the Politics of SRM
Participants explored how evolving scientific research, geopolitical tensions, and public misinformation are shaping the SRM debate. Pew Research surveys have found that in the U.S., public support for SRM is relatively low; in 2018 and again in 2021, 53% of those surveyed said that they thought SRM “would not make a difference in reducing the effects of global climate change.”
In addition, public opinion and policy on SRM has become increasingly polarized. In the U.S., 22 states have introduced legislation to ban SRM deployment. Tennessee was the first state to sign their SRM ban into law in 2024. During the roundtable, speakers observed that some political opposition to SRM appears to be derived from a broader right-wing mistrust of climate science. They also cited recent research suggesting that conspiracy theories, particularly those regarding so-called “chem trails,” have been linked to anti-SRM attitudes.
Some indigenous communities have also expressed strong opposition to SRM, citing concerns that such untested environmental manipulation will disregard traditional ecological knowledge and sovereignty. Despite the widespread mistrust and poor public perception, roundtable speakers anticipated that a government, private company, or even a wealthy individual might deploy SRM technologies within the next few decades. There was a shared emphasis on the importance of conducting essential research and developing robust governance mechanisms before it is too late.
For more information about the project or to learn more, contact globalsecurity@amacad.org.
