Solar Geoengineering Futures: Interdisciplinary Research to Inform Decisionmaking

Solar geoengineering represents a set of risky and untested—yet potentially beneficial—technologies that could help address the growing risks of climate change, especially when paired with aggressive emissions mitigation, carbon dioxide removal, and climate resilience efforts. While interest has been growing in solar geoengineering, more physical climate and social science research is needed before policymakers consider developing deployment capability. Additionally, ongoing and robust public engagement with a diverse set of global stakeholders and communities is crucial, especially as the impacts may affect regions differently.

On September 28 and 29 Resources for the Future (RFF) hosted “Solar Geoengineering Futures: Interdisciplinary Research to Inform Decisionmaking”, a two-day conference focused on the key questions informing ongoing research and decisionmaking on solar geoengineering. This hybrid event featured an interdisciplinary group of leading solar geoengineering experts exploring the major challenges, uncertainties, and potential benefits related to this emerging set of technologies.

Thursday, September 28, 2023

10:00 a.m. | Coffee and Arrival

10:30 a.m. | Welcome and Introduction
Introductions by Richard Newell and Billy Pizer

10:45 a.m. | Panel 1. Biophysical Impacts: Climatic and Non-climatic Risks and Benefits
The starting point for social science research on solar geoengineering (SG) is the biophysical parameters of a possible SG intervention. This session provided a grounding in SG knowns and unknowns, as well as ongoing research in this area.
Moderator: Peter Irvine
Panelists: John Moore, Daniele Visioni, Lili Xia, and Babatunde Abiodun

Supplemental Materials

• “Opinion: The Scientific and Community-Building Roles of the Geoengineering Model Intercomparison Project (GeoMIP)—Past, Present, and Future” by Daniele Visioni, Ben Kravitz, Alan Robock, Simone Tilmes, Jim Haywood, Olivier Boucher, Mark Lawrence, Peter Irvine, Ulrike Niemeier, Lili Xia, Gabriel Chiodo, Chris Lennard, Shingo Watanabe, John C. Moore, and Helene Muri
• “The Choice of Baseline Period Influences the Assessments of the Outcomes of Stratospheric Aerosol Injection” by Daniele Visioni, Ewa M. Bednarz, Douglas G. MacMartin, Ben Kravitz, and Paul B. Goddard
• Frozen Arctic: Horizon Scan of Interventions to Slow Down, Halt, and Reverse the Effects of Climate Change in the Arctic and Northern Regions, and Compendium by Björn Alfthan, Albert van Wijngaarden, John Moore, Lars Kullerud, Tiina Kurvits, Oda Mulelid, and Eirin Husabø
• “Potential Impacts of Stratospheric Aerosol Injection on Drought Risk Managements over Major River Basins in Africa” by Babatunde J. Abiodun, Romaric C. Odoulami, Windmanagda Sawadogo, Olumuyiwa A. Oloniyo, Abayomi A. Abatan, Mark New, Christopher Lennard, Pinto Izidine, Temitope S. Egbebiyi, and Douglas G. MacMartin
• “Optimal Climate Intervention Scenarios for Crop Production Vary by Nation” by Brendan Clark, Lili Xia, Alan Robock, Simone Tilmes, Jadwiga H. Richter, Daniele Visioni, and Sam S. Rabin
• “The Interaction of Solar Radiation Modification and Earth System Tipping Elements” by Gideon Futerman, Mira Adhikari, Alistair Duffey, Yuanchao Fan, Peter Irvine, Jessica Gurevitch, and Claudia Wieners

12:00 p.m. | Lunch
Lunch Discussion: A conversation with the Right Honourable A. Kim Campbell, P.C., former Canadian prime minister and current member of the Climate Overshoot Commission, moderated by Jonathan Wiener.

Supplemental Materials

• Reducing the Risks of Climate Overshoot by the Climate Overshoot Commission

1:30 p.m. | Panel 2. Would Solar Geoengineering Crowd Out Emissions Cuts? The “Moral Hazard” Risk Examined A key concern about solar geoengineering research is the notion of “moral hazard” risk, where any movement to consider SG weakens the motivation to pursue mitigation. This session examined the latest social science research on SG moral hazard risk.
Moderator: Joe Aldy
Panelists: Talbott Andrews, Dave McEvoy, Christine Merk, and David Morrow

Supplemental Materials

• “Knowledge about Aerosol Injection Does Not Reduce Individual Mitigation Efforts” by Christine Merk, Gert Pönitzsch, and Katrin Rehdanz
• “Presenting Balanced Geoengineering Information Has Little Effect on Mitigation Engagement” by Christine Merk and Gernot Wagner
• “Does Solar Geoengineering Crowd Out Climate Change Mitigation Efforts? Evidence from a Stated Preference Referendum on a Carbon Tax” by Todd L. Cherry, Steffen Kallbekken, Stephan Kroll, and David M. McEvoy
• “Climate Cooperation in the Shadow of Solar Geoengineering: An Experimental Investigation of the Moral Hazard Conjecture” by Todd L. Cherry, Stephan Kroll, David M. McEvoy, David Campoverde, and Juan Moreno-Cruz
• “Anticipating Moral Hazard Undermines Climate Mitigation in an Experimental Geoengineering Game” by Talbot M. Andrews, Andrew W. Delton, and Reuben Kline
• “Ethical Aspects of the Mitigation Obstruction Argument against Climate Engineering Research” by David R. Morrow
• “Research on Solar Climate Intervention Is the Best Defense Against Moral Hazard” by Daniel Bodansky and Andy Parker

2:45 p.m. | Coffee break

3:05 p.m. | Panel 3. Solar Geoengineering’s Place within the Broader Climate Strategy Portfolio If solar geoengineering is deployed, it will likely occur alongside other key climate strategies, such as emission mitigation, CO2 removal, and adaptation. The aim of this session was to describe the role of SG under different development of mitigation and adaptation policies, assuming countries cooperate to fight climate change.
Moderator: Massimo Tavoni
Panelists: Mariia Belaia, Tony Harding, Doug MacMartin, and Simone Tilmes

Supplemental Materials

• “Stability of Efficient International Agreements on Solar Geoengineering” by Irina Bakalova and Mariia Belaia
• “SRM on the Table: The Role of Geoengineering for the Stability and Effectiveness of Climate Coalitions” by Piergiuseppe Pezzoli, Johannes Emmerling, and Massimo Tavoni
• “Governing Climate Geoengineering: Side Payments Are Not Enough” by Riccardo Ghidoni, Anna Lou Abatayo, Valentina Bosetti, Marco Casari, and Massimo Tavoni
• “Impact of Solar Geoengineering on Temperature-Attributable Mortality” by Anthony Harding, David Keith, Wenchang Yang, and Gabriel Vecchi
• “Climate Econometric Models Indicate Solar Geoengineering Would Reduce Inter-Country Income Inequality” by Anthony R. Harding, Katharine Ricke, Daniel Heyen, Douglas G. MacMartin, and Juan Moreno-Cruz
• “Reaching 1.5 and 2.0°C Global Surface Temperature Targets Using Stratospheric Aerosol Geoengineering” by Simone Tilmes, Douglas G. MacMartin, Jan T. M. Lenaerts, Leo van Kampenhout, Laura Muntjewerf, Lili Xia, Cheryl S. Harrison, Kristen M. Krumhardt, Michael J. Mills, Ben Kravitz, and Alan Robock
• “Scenarios for Modeling Solar Geoengineering” by Douglas G. MacMartin, Daniele Visioni, Ben Kravitz, Jadwiga H. Richter, Tyler Felgenhauer, Walker R. Lee, David R. Morrow, Edward A. (Ted) Parson, and Masahiro Sugiyama

4:20 p.m. | Day 1 Closing Remarks

4:30 p.m. | Reception
Please join us for a welcome reception concluding at 5:30 p.m.

Friday, September 29, 2023

9:00 a.m. | Panel 4. Plausible Non-optimal Near-term Solar Geoengineering Scenarios Several decades of experience with global coordination and cooperation around climate mitigation suggests that solar geoengineering might emerge in a non-optimal manner. This session examined how this might happen, what it might mean, and what actions might be warranted in the near term.
Moderator: Tyler Felgenhauer
Panelists: Beth Chalecki, Joshua Horton, Jessica Seddon, and Erin Sikorsky

Supplemental Materials

• “Environmental Peacebuilding and Solar Geoengineering” by Holly Jean Buck
• “The International Politics of Climate Engineering: A Review and Prospectus for International Relations” by Joshua B. Horton and Jesse L. Reynolds
• “A New Security Framework for Geoengineering” by Elizabeth L. Chalecki and Lisa L. Ferrari
• “Eighteen Politically Relevant Solar Geoengineering Scenarios” by Andrew Lockley, Yangyang Xu, Simone Tilmes, Masahiro Sugiyama, Dale Rothman, and Adrian Hindes

10:15 a.m. | Coffee Break

10:35 a.m. | Panel 5. Capacity Building for Competent, Just, and Inclusive Decisionmaking As momentum around research and governance discussions is growing, questions arise around how we should make decisions around both research and potential deployment of solar geoengineering, and who is part of a decision-making process. This panel examined key steps to enabling and building meaningful engagement in this space.
Moderator: Shuchi Talati
Panelists: Julie Arrighi, Marion Hourdequin, Hassaan Sipra, and Billy Williams

Supplemental Materials

• Building Solar Geoengineering Governance Capacity by the Alliance for Just Deliberation on Solar Geoengineering
• “Who Are the Engineers? Solar Geoengineering Research and Justice” by Olúfẹ́mi O. Táíwò and Shuchi Talati
• “Editorial: Solar Geoengineering in the Horizon: Humanitarian Dimensions” by Julie Arrighi, Roop Singh, Sikina Jinnah, and Pablo Suarez
• Ethical Framework for Climate Intervention Research: Draft Principles by the American Geophysical Union
• “Geoengineering Justice: The Role of Recognition” by Marion Hourdequin

12:00 p.m. | Lunch
Lunch Discussion: A conversation on the NOAA Earth Radiation Budget Initiative with Greg Frost, Special Advisor for Carbon Dioxide Removal and Solar Radiation Modification at NOAA, moderated by Kristin Hayes.

Supplemental Materials

• NOAA’s Earth Radiation Budget Initiative by the US National Oceanic and Atmospheric Administration

1:30 p.m. | Panel 6. Important Next Steps for Policy and Research: A Solar Geoengineering Research Agenda for the Next Decade In this final panel, we brought together themes from the previous session in a discussion of funding and policy possibilities and priorities.
Moderator: Shannon Osaka
Panelists: Holly Buck, David Keith, Andy Parker, and Ted Parson

Supplemental Materials

• “Toward a Responsible Solar Geoengineering Research Program” by David Keith
• “Developing Countries Must Lead on Solar Geoengineering Research” by A. Atiq Rahman, Paulo Artaxo, Asfawossen Asrat and Andy Parker
• Congressionally Mandated Research Plan and an Initial Research Governance Framework Related to Solar Radiation Modification by the Office of Science and Technology Policy
• “Social Science Research to Inform Solar Geoengineering” by Joseph E. Aldy, Tyler Felgenhauer, William Pizer, Massimo Tavoni, Mariia Belaia, Mark E. Borsuk, Arunabha Ghosh, Garth Heutel, Daniel Heyen, Joshua Horton, David Keith, Christine Merk, Juan Moreno-Cruz, Jesse L. Reynolds, Katharine Ricke, Wilfried Rickels, Soheil Shayegh, Wake Smith, Simone Tilmes, Gernot Wagner, and Jonathan Wiener
• Reflecting Sunlight: Recommendations for Solar Geoengineering Research and Research Governance by the National Academies of Science, Engineering, and Medicine
• Solar Radiation Modification: A Risk-Risk Analysis by Tyler Felgenhauer, Govindasamy Bala, Mark E. Borsuk, Matthew Brune, Inés Camilloni, Jonathan B. Wiener, and Jianhua Xu
• Challenging Climate podcast by Jesse Reynolds and Pete Irvine

2:45 p.m. | Closing Remarks

The Resources for the Future Solar Geoengineering research project applies tools from multiple social science research disciplines to better understand the risks, potential benefits, and societal implications of solar geoengineering as a possible approach to help reduce climate risk—in addition to more aggressive and necessary mitigation, carbon dioxide removal, and adaptation efforts. The project began in 2020 with a series of three expert workshops convened under the SRM Trans-Atlantic Dialogue. These meetings resulted in a 2021 article in Science that lays out a set of key social science research questions to pursue with solar geoengineering. The Project followed this by sponsoring eight research papers along with two author workshops, addressing several of these research areas. With these papers—and now this public symposium—we aim to engage with a broader set of researchers from around the globe, a growing number of interested stakeholders, and the public.