The Board on Atmospheric Sciences and Climate; Division on Earth & Life Studies
The Committee on Science, Technology, and Law; Policy and Global Affairs Division
National Academies of Sciences, Engineering, and Medicinestudy title


Statement of Task

The National Academies of Sciences, Engineering, and Medicine proposes to undertake a study that would develop a research agenda and recommend research governance approaches for climate intervention strategies that reflect sunlight to cool Earth. The proposed study would aim to address research needs and relevant research governance in tandem, such that the understanding and thinking on each can inform the other.

The study will focus on sunlight reflection strategies that involve atmospheric interventions, including marine cloud brightening, stratospheric aerosol injection, and cirrus cloud modification. It will consider trans-disciplinary research related to understanding the baseline chemistry, radiative balance, and other characteristics of the atmosphere; estimating the potential impacts and risks, both positive and negative, of these interventions on the atmosphere, climate system, natural and managed ecosystems, and human systems; technological feasibility of these interventions; and approaches and metrics for detecting, monitoring and quantifying the multiple physical and societal impacts of solar climate interventions.

The study will explore and recommend appropriate research governance mechanisms at international, national, and sub-national scales. It will consider research governance that already exists, examples of research governance mechanisms currently being used or considered for other areas of scientific inquiry that could be adapted to the realm of climate intervention research, and any potentially new frameworks required.

The committee will include two subpanels (composed of members of the committee) that will organize two workshops to address the research agenda and research governance considerations listed below. Drawing upon these workshops, other information gathering activities, and deliberations among the full membership, the committee will author a single consensus report providing its findings and recommendations.  The committee will:

1. Develop a detailed trans-disciplinary research agenda for sunlight reflection strategies. The committee will assess questions such as:

  • What research is needed to assess the feasibility, efficacy, and risks of the proposed approaches?
  • What research is needed to assess likely impacts and risks of reduced solar radiation on key global systems (including the oceans, ice sheets, food and fiber production, human health, solar and wind energy, terrestrial ecosystem functioning and biodiversity, and global biogeochemical cycles) and on achieving the UN’s Sustainable Development Goals? What are the risks (environmental, social, geopolitical) of conducting such research?
  • What research is needed to assess how reducing solar radiation could help avoid or trigger critical transitions in environmental systems?
  • What relevant research is happening currently in the United States and abroad?  What have we learned from this work?
  • What are the important knowledge gaps and key technical constraints (such as model resolution or cloud physics)?
  • What research is needed to address the knowledge gaps and key technical constraints?  What are reasonable research goals for the next decade?
  • What investments in observations, modeling capabilities, and other supporting research infrastructure will be necessary to advance the research agenda?
  • What are benefits of the proposed research in advancing other areas of science?

2. Explore and recommend appropriate research governance mechanisms.  The committee will assess questions such as:

  • How best to foster meaningful public participation and consultation in research planning and oversight, and to ensure transparency and accountability regarding a project’s goals and plans, potential risks, and eventual results?
  • How to ensure that research is designed to minimize the chances of unintended impacts and is aimed at promoting the collective benefit of humankind and the environment?
  • How to identify and apply professional standards of good scientific conduct?
  • How to balance adequate oversight, review, public consultation, and approval mechanisms with norms for freedom of scientific inquiry?
  • How to harness the benefits of potential private sector involvement (e.g., innovation, capital investment, cost minimization) without creating vested financial interests in operational deployment, inappropriate intellectual property claims, or threats to national and international public good?
  • What statutory limits might affect what work can be funded by federal agencies and what research may need to adhere to particular existing federal policies or international agreements or processes?
  • How to identify the governance mechanisms that should be in place in advance of field research at various scales?

The committee will be encouraged to look at examples of research governance mechanisms currently being used or considered for other areas of scientific inquiry that could be adapted to the realm of climate intervention research.

Study Committee

CHRISTOPHER B. FIELD (CHAIR), NAS, Stanford University
DR. CHRISTOPHER B. FIELD (NAS) is the Perry L. McCarty Director of the Stanford Woods Institute for the Environment and Melvin and Joan Lane Professor for Interdisciplinary Environmental Studies. His research focuses on climate change, ranging from work on improving climate models, to prospects for renewable energy systems, to community organizations that can minimize the risk of a tragedy of the commons. Field was the founding director of the Carnegie Institution’s Department of Global Ecology, a position he held from 2002 to 2016. He was co-chair of Working Group II of the Intergovernmental Panel on Climate Change from 2008-2015, where he led the effort on the IPCC Special Report on “Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation” (2012) and the Working Group II contribution to the IPCC Fifth Assessment Report (2014) on Impacts, Adaptation, and Vulnerability. His widely cited work has earned many recognitions, including election to the National Academy of Sciences, the Max Planck Research Award, and the Roger Revelle Medal. Dr. Field’s A.B. is in Biology from Harvard (1975). His Ph.D. is in Biology from Stanford (1981). For the National Academies, Dr. Field served as a member of the Board on Environmental Studies and Toxicology and he has recently served on the Advisory Board for the Gulf Research Program, the Committee to Review the Draft Climate Science Special Report, and the 2017-2027 Decadal Survey for Earth Science and Applications from Space.

WILLIAM W. L. CHEUNG, University of British Columbia
DR. WILLIAM W. L. CHEUNG is a Canada Research Chair in Ocean Sustainability and Global Change, and associate professor at the Institute for the Oceans and Fisheries at the University of British Columbia (UBC). He also is the Director (Science) of the Nippon Foundation-UBC Nereus Program. His main research areas include understanding the responses and vulnerabilities of marine ecosystems and fisheries to global change, exploring solution options to meet climate challenges in the ocean, and examining trade-offs in managing and conserving living marine resources. His works cut across multiple disciplines, from oceanography to ecology, economics and social sciences, and range from local to global scales. William has published over 150 peer-reviewed publications, including papers in leading international journals. William is actively involved in international and regional initiatives that bridge science and policy. For instance, currently, he is a coordinating lead author for the Intergovernmental Panel on Climate Change (IPCC) Special Report for the Oceans and Cryosphere in the Changing Climate. He was a Lead Author in the Working Group II of the Fifth Assessment Report of the IPCC, a Coordinating Lead Author of the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) and Global Biodiversity Outlook. He serves as associate editor for Global Change Biology and Frontiers in Ecology and the Environment (ESA Journal), and member of the editorial board of Fish and Fisheries, Fisheries Oceanography and Frontier in Marine Sciences, and as scientific advisors in a number of international and local organizations. William obtained his B.Sc. in biology (1998) and M.Phil. (2001) from the University of Hong Kong. He worked for WWF Hong Kong for two years, after which he completed his Ph.D. in resource management and environmental studies at UBC (2007). From 2009 to 2011, he was Lecturer in Marine Ecosystem Services in the School of Environmental Sciences, University of East Anglia.

LISA DILLING, University of Colorado, Boulder
DR. LISA DILLING is Associate Professor of Environmental Studies, a Fellow of the Cooperative Institute for Research in Environmental Sciences (CIRES) and a member of the Center for Science and Technology Policy Research at the University of Colorado, Boulder. She is Director of the Western Water Assessment, a NOAA Regional Integrated Sciences and Assessment project that studies and facilitates the use of climate information in decision-making in the Intermountain West. Professor Dilling’s scholarship focuses on decision-making, the use of information and science policies related to climate change, adaptation, carbon management, and geoengineering. Her current projects examine drought in urban water systems, water governance and climate change, municipal adaptation to hazards, decision-making in public lands management, and knowledge for adaptation among pastoralists. She has authored numerous articles and is co-editor of the book, “Creating a Climate for Change: Communicating Climate Change and Facilitating Social Change” from Cambridge University Press. She also spent the 2016-2017 academic year at the Institute for Science, Innovation and Society at the University of Oxford supported by a Leverhulme Trust Visiting Professorship. Professor Dilling received her Ph.D. in biological sciences from the University of California, Santa Barbara in 1997.

PETER C. FRUMHOFF, Union of Concerned Scientists
DR. PETER C. FRUMHOFF is director of science and policy and chief climate scientist at the Union of Concerned Scientists (UCS). A global change ecologist, Dr. Frumhoff has published widely at the nexus of climate science and policy including on the climate responsibilities of fossil fuel companies, the attribution of extreme events to climate change, the ecological impacts of climate change, the role of forests and land use in climate mitigation, and the societal responsibilities of geoengineering researchers. He is a member of the Board on Atmospheric Sciences and Climate at the National Academies of Science, Engineering and Medicine. He was a lead author of the Intergovernmental Panel on Climate Change’s (IPCCs) 2007 Fourth Assessment Report and the 2000 IPCC Special Report on Land Use, Land-Use Change, and Forestry, and served as chair of the 2007 Northeast Climate Impacts Assessment. He served on the Advisory Committee on Climate Change and Natural Resource Science at the U.S. Department of the Interior and the board of directors of the American Wind Wildlife Institute. In 2014, Dr. Frumhoff was the Cox Visiting Professor in the School of Earth Sciences at Stanford University. Previously, he taught at Tufts University, Harvard University, and the University of Maryland. He also served as an AAAS Science and Diplomacy Fellow at the U.S. Agency for International Development, where he designed and led conservation and rural development programs in Latin America and East Africa. He holds a Ph.D. in ecology and an M.A. in zoology from the University of California, Davis, and a B.A. in psychology from the University of California, San Diego.

HENRY T. GREELY, Stanford University
MR. HENRY T. GREELY (Hank) is Deane F. and Kate Edelman Johnson Professor of Law and Professor, by courtesy, of Genetics at Stanford University. He specializes in ethical, legal, and social issues arising from advances in the biosciences, particularly from genetics, neuroscience, and human stem cell research. Professor Greely is President of the International Neuroethics Society, directs the Stanford Center for Law and the Biosciences, and the Stanford Program on Neuroscience in Society, chairs the California Advisory Committee on Human Stem Cell Research, and serves on the NIH BRAIN Initiative’s Multi-Council Working Group, which Neuroethics Working Group he co-chairs. For the National Academies, he serves on the Committee on Science, Technology, and Law. In May 2016, he published the book, The End of Sex and the Future of Human Reproduction. Professor Greely graduated from Stanford in 1974 with a bachelor’s degree in political science and from Yale Law School with a J.D. in 1977. He served as a law clerk for Judge John Minor Wisdom on the United States Court of Appeals for the Fifth Circuit and for Justice Potter Stewart of the United States Supreme Court. After working during the Carter Administration in the Departments of Defense and Energy, he entered private law practice in Los Angeles in 1981. He joined the Stanford faculty in 1985.

DR. MARION HOURDEQUIN is Associate Professor and Chair of the Department of Philosophy at Colorado College. Her research focuses on ethics and justice in relation to climate change and climate engineering; the social and ethical dimensions of ecological restoration; and environmental ethics. She has published work in a variety of journals, including Environmental Ethics; Environmental Values; Ethics & the Environment; Ethics, Policy, & Environment; Science, Technology, & Human Values; and Ethical Theory and Moral Practice. She is the author of Environmental Ethics: From Theory to Practice (Bloomsbury, 2015) and editor, with David Havlick, of Restoring Layered Landscapes (Oxford, 2016). Dr. Hourdequin is Vice President of the International Society for Environmental Ethics, and she currently serves as an Associate Editor for the journal Environmental Values and on the Editorial Board of Environmental Ethics. She earned her PhD in Philosophy at Duke University (2005) and her undergraduate degree in Ecology and Evolutionary Biology at Princeton University (1995).

JAMES W. HURRELL, Colorado State University
JAMES W. HURRELL is the Scott Presidential Chair of Environmental Science and Engineering at Colorado State University. He is a former Director of the National Center for Atmospheric Research (NCAR), where he was also a Senior Scientist in the Climate and Global Dynamics Laboratory (CGD). He is the former Chief Scientist of Community Climate Projects in CGD, which includes the Community Earth System Model (CESM), and a former Director of CGD and the NCAR Earth System Laboratory. Jim spent a year as a visiting scientist at the Hadley Centre for Climate Prediction and Research in the U.K. He received a Ph. D. (1990) in Atmospheric Science from Purdue University. Jim’s research has centered on empirical and modeling studies and diagnostic analyses to better understand climate, climate variability, and climate predictability. He has received numerous awards for his research, and he is a Fellow of the Royal Meteorological Society, the American Meteorological Society, and the American Geophysical Union. Jim was honored for his contributions to climate science by giving the Fridtjof Nansen Memorial Lecture to the Norwegian Academy of Science and Letters, where he was also awarded the Nansen Medal. He has been extensively involved in the World Climate Research Programme (WCRP) on Climate Variability and Predictability (CLIVAR), including roles as co-chair of the Scientific Steering Group (SSG) of both U.S. and International CLIVAR, and membership on several other CLIVAR panels. He is currently an officer of the Joint Scientific Committee of WCRP. Jim was elected to and served on the Council of the AMS, and he currently serves as the President of the Atmospheric Sciences Section of the AGU. Jim has provided briefings and testimonies to both the U.S. Senate and the House of Representatives on climate science, and he has served on several National Academy committees. These include A National Strategy for Advancing Climate Modeling (2011-2013), The U.S. Climate Change Science Program (2006-2009), Climate Data Records from Operational Satellites: Development of a NOAA Satellite Data Utilization Plan (2003-2005), and The Global Energy and Water Cycle Experiment (1997-2000).

ANDREW LIGHT, George Mason University
ANDREW LIGHT is University Professor of Philosophy, Public Policy, and Atmospheric Sciences at George Mason University, and Distinguished Senior Fellow in the Climate Program at the World Resources Institute, in Washington, D.C. From 2013-2016 he served as Senior Adviser and India Counselor to the Special Envoy on Climate Change and Staff Climate Adviser in the Secretary of State’s Office of Policy Planning, in the U.S. Department of State. In this capacity he served on the senior strategy team for the UN climate negotiations, Director of the U.S.-India Joint Working Group for Combating Climate Change, and Chair of the Interagency Climate Working Group on the Sustainable Development Goals, among other duties. In recognition of this work, Andrew was awarded the inaugural Alain Locke Award for Public Philosophy, from the Society for the Advancement of American Philosophy in March 2016, and, with the larger State Department team working on Paris, a Superior Honor Award, from the U.S. Department of State in July 2016, for “contributions to the U.S. effort that made the 21st Conference of the Parties to the UN Framework Convention on Climate Change in Paris, where the landmark Paris Agreement was concluded, a historic success.” In his academic work, Andrew is the author of over 100 articles and book chapters, primarily on the normative dimensions of environmental policy, especially on climate change, restoration ecology, and urban sustainability, and has authored, co-authored, and edited 19 books, including Environmental Values (2008), Controlling Technology (2005), Moral and Political Reasoning in Environmental Practice (2003), Technology and the Good Life? (2000), and Environmental Pragmatism (1996).

ALBERT LIN, University of California, Davis School of Law
MR. ALBERT LIN is a Professor of Law at the University of California, Davis School of Law, where he specializes in environmental and natural resources law and also teaches evidence. His research interests include toxic torts and the relationship between emerging technologies, the environment, and law. Prior to joining the UC Davis faculty in 2003, Professor Lin was a trial attorney for the Environment and Natural Resources Division of the U.S. Department of Justice. He is also the author of Prometheus Reimagined: Technology, Environment, and Law in the 21st Century (Univ. of Michigan Press 2013) and the co-author of a widely used environmental law casebook. He received his J.D. from the University of California, Berkeley School of Law (1996), his M.P.P. from the Harvard Kennedy School (1995), and his B.S. in biology from Emory University (1992).

DOUGLAS MacMARTIN, Cornell University
DR. DOUGLAS MacMARTIN is a senior research associate in the Sibley School of Mechanical & Aerospace Engineering at Cornell University, and also a Visiting Researcher in Computing + Mathematical Sciences at the California Institute of Technology. Prior to joining Caltech in 2000, he led the active control research and development program at United Technologies Research Center. His primary research focus is on solar climate engineering (geoengineering), working to develop the knowledge base to support informed future societal decisions. This includes using design principles to assess what outcomes are possible from different strategies, simulating projected climate impacts of those strategies, how to assess and manage uncertainty, as well as supporting ongoing efforts to develop governance. Dr. MacMartin’s research interests also include applying engineering dynamics and feedback analysis to study climate dynamics more broadly, as well as control design for the Thirty Meter Telescope project. He has authored or coauthored more than 70 journal articles and 70 conference papers, as well as several book chapters, and patents on active noise control. In 2017 he testified in the US Congress at a hearing on geoengineering, and has provided numerous briefings including to the UN Environment Program. He received his Bachelors’ degree in engineering science from the University of Toronto in 1987, and Masters and Ph.D. in Aeronautics and Astronautics from MIT in 1990 and 1992, respectively.

ROBERT McHENRY, Palo Alto Research Center
MR. ROBERT McHENRY is a Palo Alto Research Center (PARC) Executive in Residence (EIR), conducting a comprehensive business case analysis of a PARC technology to assess and optimally structure it for commercialization. Since joining PARC in 2012, Rob has managed the Energy Technology Program, created and led the Public Sector Operations team that manages the Government sponsored research portfolio that fuels PARC’s early stage R&D, and served as the Chief Operating Officer leading company-wide technical project execution and business support services. Previously he was a Program Manager at the Defense Advanced Research Projects Agency (DARPA), led a defense technology consulting firm, and he began his career as a nuclear submarine officer in the U.S. Navy. Rob has an M.S. in nuclear engineering from the Massachusetts Institute of Technology, and a B.S. in marine engineering from the U.S. Naval Academy.

JUAN MORENO-CRUZ, University of Waterloo
DR. JUAN MORENO-CRUZ is an Associate Professor at the School of Environment, Enterprise and Development and the Canada Research Chair in Energy Transitions at the University of Waterloo. He is also a CESifo Research Affiliate. He earned his Ph.D. in Economics from the University of Calgary in Canada in 2010, and his B.Sc. (2003) and M.Sc. (2004) in Electrical Engineering from the Universidad de Los Andes in Colombia. Prior to his current position, he was an Associate Professor in the School of Economics at the Georgia Institute of Technology (2011-2017), where he remains an Adjunct Professor. He has been a Visiting Researcher in the Department of Global Ecology of the Carnegie Institution for Science at Stanford University and an Advisor for Carnegie Energy Innovation (since 2017). Moreno-Cruz’s research focuses on the interaction of energy systems, technological change, and climate policy. Moreno-Cruz has investigated how technologies designed to modify the climate affect the strategic interaction among nations. His work on climate geoengineering economics has been published in top journals in his field and presented at venues across the US, Canada and Europe. Moreno-Cruz’s work is at the intersection between applied theory and public policy.

KATHARINE RICKE, University of California, San Diego
DR. KATHARINE RICKE is an assistant professor at the School of Global Policy & Strategy at the University of California, San Diego, and holds a joint appointment with the Scripps Institution of Oceanography. She is a climate change scientist who integrates tools from the physical and social sciences to analyze climate policy problems. Dr. Ricke recently served as a research associate in the Sibley School of Mechanical and Aerospace Engineering at Cornell University and a fellow at the Carnegie Institution for Science. Her publications on solar geoengineering have included physical science on the regional climate effects, economic analysis of the strategic incentives created by geoengineering impacts, and foreign policy analysis of the international relations implications of solar geoengineering. Her research develops methods for accounting for uncertainty and heterogeneity in both the effects of climate change and in preferences for how to address them. She has analyzed uncertainty associated with phenomena including ocean acidification’s effects on coral reefs, the warming effect from an emission of carbon dioxide today, the social cost of carbon and decadal climate variability’s influence on international climate agreements. Dr. Ricke received her B.S, in earth, atmospheric and planetary science from MIT and her Ph.D. in engineering and public policy from Carnegie Mellon University.

LYNN M. RUSSELL, Scripps Institution of Oceanography
DR. LYNN M. RUSSELL is Professor of Climate, Atmospheric Science & Physical Oceanography at Scripps Institution of Oceanography, University of California, San Diego, where she has led the Climate Sciences Curricular Group since 2009. Her research focuses on the processes that control atmospheric aerosols and their cloud interactions. Dr. Russell’s work uses both modeling and measurement studies of atmospheric particles and their chemical composition and she has studied marine aerosols, flux and entrainment in the marine boundary layer, terrestrial biogenic particles, combustion emissions, and feedbacks between climate and particle sources. She completed undergraduate degrees at Stanford University and received her Ph.D. in chemical engineering from the California Institute of Technology for her studies of marine aerosols. Her postdoctoral work as part of the National Center for Atmospheric Research Advanced Studies Program investigated aerosol and trace gas flux and entrainment in the marine boundary layer. She served on the faculty of Princeton University in the Department of Chemical Engineering before accepting her current position at Scripps in 2003. Dr. Russell has been honored with young investigator awards from ONR, NASA, Dreyfus Foundation, NSF, and the James S. McDonnell Foundation, and she received the Kenneth T. Whitby Award from AAAR (2003) for her contributions on atmospheric aerosol processes. She was elected as a fellow of AAAR in 2014 and of AGU in 2017. Dr. Russell also served as a member of the National Academy of Sciences’ Committee on Geoengineering Climate: Technical Evaluation and Discussion of Impacts, which produced two reports, including Climate Intervention: Reflecting Sunlight to Cool Earth in 2015.

AMBUJ D. SAGAR, Indian Institute of Technology, Delhi
DR. AMBUJ D. SAGAR is the Vipula and Mahesh Chaturvedi Professor of Policy Studies and the founding Head of the School of Public Policy at the Indian Institute of Technology Delhi. Ambuj’s interests broadly lie at the intersection of science, technology and development. His work has focused on innovation policy for meeting sustainability and inclusivity challenges, energy innovation policy and strategies (in areas such as biofuels, clean cookstoves, coal power, automobiles, and institutional mechanisms such as climate innovation centers), climate change policy and politics, capacity development, and higher education policy. He has been an advisor/consultant to various Indian Govt. ministries as well as many multilateral and bilateral agencies. Ambuj did his undergraduate studies in Mechanical Engineering (1985) at IIT Delhi. He subsequently received an M.S. in Aerospace Engineering (1986) from the University of Michigan and then an M.S. in Materials Science (1989), a Ph.D. in Polymers (1994), and an M.S. in Technology and Policy (1994) from the Massachusetts Institute of Technology.

PAUL O. WENNBERG, NAS, California Institute of Technology
DR. PAUL O. WENNBERG (NAS) is R. Stanton Avery Professor of Atmospheric Chemistry and Environmental Science and Engineering and the Director of Ronald and Maxine Linde Center for Global Environmental Science at the California Institute of Technology. He has made seminal contributions to the understanding of stratosphere and troposphere composition and their impacts on climate, ozone depletion, and air quality. His advances have come from the development of state-of-the-art in situ laboratory, air-borne, and ground-based instruments, of space-based remote sensors, and highly insightful interpretation of these measurements. Dr. Wennberg’s laboratory studies the photochemistry of volatile organic compounds emitted by both humans and the biosphere. This chemistry is important for determining the levels of oxidants (e.g., ozone) and aerosol. His lab has developed new instruments for measurement of the oxidation products of these organic compounds. These instruments have participated in numerous field campaigns across the world. Dr. Wennberg’s laboratory has also been at the center of the development of space- and ground-based measurement of greenhouse gases by remote sensing. He has helped to create the Total Carbon Column Observing Network (TCCON) that is used as the ground-based standard for measurement of greenhouse gas column abundance. Dr. Wennberg earned his B.A. in chemistry from Oberlin College in 1985 and his Ph.D. in physical chemistry from Harvard University in 1994. He was elected into the National Academy of Sciences in 2017 as a member of the geophysics section.

The committee membership has changed as of May 30, 2019 with the addition of Dr. James W. Hurrell.
The committee membership has changed as of June 10, 2019 with the resignation of Ms. Susan Biniaz.

Project Staff

Katie Thomas, Senior Program Officer, BASC
Katie Thomas is a Senior Program Officer for the Board on Atmospheric Sciences and Climate. She earned an M.S. in Environmental Science and Policy from Johns Hopkins University in 2009 and a B.S. from the University of Michigan in 2004. Since joining the National Academies in 2006, she has directed a number of high-profile studies on topics such as carbon dioxide removal, methane emissions, and extreme event attribution. She has also served as the rapporteur for four workshop summaries: Urban Forestry: Toward an Ecosystem Services Research Agenda; Linkages Between Arctic Warming and Mid-Latitude Weather Patterns; Improving the Understanding of Clouds and Aerosols in Climate Models; and Antarctic Sea Ice Variability in the Southern Ocean-Climate System.

Steven Kendall, Program Officer, CSTL
Steven Kendall, Ph.D., is program officer for the Committee on Science, Technology, and Law. He received his Ph.D. from the University of California, Santa Barbara in 2011. Dr. Kendall has contributed to numerous National Academies of Sciences, Engineering, and Medicine reports including Securing the Vote: Protecting American Democracy (2018)Optimizing the Nation’s Investment in Academic Research (2016)International Summit on Human Gene Editing: A Global Discussion (2015)Identifying the Culprit: Assessing Eyewitness Identification (2014); Positioning Synthetic Biology to Meet the Challenges of the 21st Century (2013); and others.

Laurie Geller, Senior Program Officer, BASC
Laurie Geller is Senior Program Officer for the National Academies’ Polar Research Board (PRB) and for the Board on Atmospheric Sciences and Climate (BASC). She has more than a decade of experience with the National Academies, directing numerous activities addressing polar science, climate and global change, air pollution, sustainable development, and other related topics. In recent years this has included managing the Arctic Matters public engagement initiative, the Committee on Strategic Planning for the Antarctic and Southern Ocean Research, the Committee to Advise the U.S. Global Change Research Program, the joint NAS/UK Royal Society booklet Climate Change: Evidence and Causes, and the America’s Climate Choices suite of studies. Outside of her National Academies role, she has served as an AAAS Science Policy Fellow (with the U.S. EPA), as a Program Officer at the International Council for Science (ISCU) secretariat in Paris, and as a visiting Professor at American University-Paris. She has a Ph.D. in atmospheric chemistry from the University of Colorado-Boulder.

Erin Markovich, Research Associate, BASC
Erin Markovich is currently a research associate with the Board on Atmospheric Science and Climate (BASC) and the Polar Research Board (PRB) at the National Academies. She was born and raised in Naperville, Illinois, a southwest suburb of Chicago. In May 2015, she earned a bachelor’s degree in atmospheric sciences from the University of Illinois at Urbana-Champaign and in August of that year, she moved to Washington, DC, to work for the National Academies. Erin has been a staff member of BASC and PRB since then and has provided support to numerous studies across the Academies in an administrative and research capacity. Erin remains connected to the atmospheric science community by staying involved in the American Meteorological Society and furthers her education both formally and informally through coursework and literature readings.

Michael Hudson, Senior Program Assistant
Michael Hudson grew up in Roanoke, VA and in 2014, graduated from James Madison University in Harrisonburg, Virginia with a B.S. in Geographic Science concentrating in Environmental Conservation, Sustainability, and Development with a minor in Environmental Science. After graduating, and without a clear career path, Michael pursued nonprofit work in Roanoke and joined AmeriCorps while working alongside a local nonprofit, The Advancement Foundation, as a community and economic developer. Harnessing that passion for nonprofit work and a background in environmental sciences, Michael moved to Washington, DC in January 2015 to pursue a position combining the two. It was then he briefly worked for the Sierra Club’s Beyond Coal Campaign before gaining full-time employment at the National Academies and BASC/PRB. Outside of work, Michael enjoys exploring DC, cross country skiing, happy hours, and the mountains of the Blue Ridge Valley.

Study FAQ

What is the National Academies of Sciences, Engineering, and Medicine (NASEM)?

NASEM is a private, nonprofit institution chartered by Congress in 1863 to provide science, technology, and health policy advice to the government. It is not part of the U.S. government.  NASEM enlists leading scientists, engineers, and other experts to answer scientific and technical issues facing the United States and the world. Members of study committees serve as volunteers and are not paid for their service.

Why is NASEM doing a study on strategies to reflect sunlight?

Global greenhouse gas emissions are continuing to increase and many countries’ efforts to meet emission reduction targets are falling short of the goals enshrined in the “Paris Agreement” on limiting global climate change. Minimizing and managing the anticipated climate change risks will require a portfolio of response strategies. There is widespread recognition that this portfolio must involve reducing greenhouse gas emissions to the atmosphere (“mitigation”), adapting to climate change impacts that are unavoidable, and finding ways to remove and reliably sequester carbon from the atmosphere. While more controversial, there has been continued and growing interest to also explore possible strategies for limiting climate change through a variety of “climate intervention” or “geoengineering” approaches, including those that modify the amount of solar heating of the Earth.

Some of the main “solar radiation management” approaches of interest involve widespread distribution of small reflective particles in the stratosphere, augmentation of reflective cloud cover in the lower atmosphere,  and reduction of cirrus clouds that trap outgoing radiation in the upper troposphere. Preliminary modeling work indicates that these approaches do have the potential to reduce some near-term risks of climate change. However, they also introduce a wide array of potential risks (environmental, ethical, social, political, economic, legal), and concerns about such risks have thus far greatly constrained research on the topic, including the basic modeling and process-level research that must be advanced before even considering any real-world deployment studies at scales that would have a discernible effect on climate.

To address these challenges, there is a need to better define a research agenda that would improve our understanding of the potential effectiveness and of the potential risks of solar radiation management techniques. There is a parallel need to reach consensus on approaches and systems for governing such research. This NASEM study will explore these two needs in tandem, to allow iterative engagement and learning between those seeking to guide scientific research and those seeking to guide the governance of this research.

What is the focus of the study?

The study will focus on sunlight reflection strategies that involve atmospheric interventions, including marine cloud brightening, stratospheric aerosol injection, and cirrus cloud modification. It will consider trans-disciplinary research related to understanding the baseline chemistry, radiative balance, and other characteristics of the atmosphere; potential impacts and risks (both positive and negative) of these interventions on the atmosphere, climate system, natural and managed ecosystems, and human systems; technological feasibility of these interventions; and approaches and metrics for detecting, monitoring and quantifying the multiple physical and societal impacts of solar climate interventions.

The study will explore and recommend appropriate research governance mechanisms at international, national, and sub-national scales. It will consider research governance that already exists, examples of research governance mechanisms currently being used or considered for other areas of scientific inquiry that could be adapted to the realm of climate intervention research, and any potentially new frameworks required.

Has NASEM provided this type of guidance before?

Yes.  In 2015, NASEM released a study, Climate Intervention: Reflecting Sunlight to Cool Earth, which was conducted to better understand the potential cost and performance of proposed strategies. This new study will build directly upon that earlier effort by focusing more directly in defining a research agenda and defining strategies for governing this research.

How are committee members chosen?

The Academies issues calls for nominations for committee members, seeking recognized experts from diverse disciplines and backgrounds. Each committee must include the full range of expertise and experience needed to address the study’s statement of task. The overall composition of the committee is evaluated to make sure that points of view are reasonably balanced so that the committee can carry out its charge objectively and credibly. A provisional slate is posted for a 20-day comment period. Once approved by the Presidents of the National Academies of Sciences, Engineering, and Medicine, all committee members are screened for conflict of interest. Committee members serve without pay and deliberate free of outside influence.

When does the committee meet?

The committee meets throughout the study process. The committee has currently scheduled the following meetings:

  • August 7-9 in Boulder, CO. Will include a public workshop and closed committee meeting.
  • September 10-12 in Palo Alto, CA. Will include a public workshop and closed committee meeting.
  • October 17-18, location TBD. Will include a brief open session; the remainder will be a closed committee meeting.
  • January 22-23, 2020, location TBD. This meeting will be closed in its entirety.

Additional information about these meetings will be posted on the website and sent out in email notifications as it becomes available.

When will the study be completed?

The study will be completed in summer 2020.

Can I attend committee meetings?

All meetings in which the committee gathers information are open to the public. All meetings will be open via the web, and presentations will be recorded and posted to the study’s website.

Can I provide comments or information to the committee?

Yes. At information-gathering meetings, members of the public can present comments to the committee. Members of the public may also submit written statements and relevant information by emailing

Can I see the comments and information submitted to the committee?

Written materials submitted to a study committee by external sources are listed in the project’s public access file and can be made available to the public upon request. For a copy of the list and to obtain copies of the materials (free to press and government employees) please send inquiries to:

Public Access Records Office (PARO)
The National Academies
Washington DC 20001
Tel: 202.334.3543

Normal business hours for PARO are 9:00 am to 5:00 pm, Monday through Friday.

Are Academies studies peer reviewed?

Yes. As a final check on the quality and objectivity of the study, all Academies reports must undergo a rigorous, independent external review by experts whose comments are provided anonymously to the committee members. The review process is structured to ensure that each report addresses its approved study charge and does not go beyond it, that the findings are supported by the scientific evidence and arguments presented, that the exposition and organization are effective, and that the report is impartial and objective.

Will the results of the study be made available to the public?

Yes.  After all committee members and appropriate Academies officials have signed off on the final report, it is transmitted to the sponsor of the study and is released to the public. An electronic version of the final report will be available to download for free at upon completion of the study.

How will the results of this study be used?

The committee will produce a consensus report with findings and recommendations that will be available to the public upon its release after undergoing a rigorous external peer-review process. The final report will be directed at policy makers, the public, and the scientific community, and will be delivered to the study sponsors and to various parts of the U.S. government, including the U.S. Congress and the executive branch. Other derivative products will be designed to communicate the report’s findings to a lay audience.

Related Reports

Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration and Climate Intervention: Reflecting Sunlight to Cool Earth

Climate intervention is no substitute for reductions in carbon dioxide emissions and adaptation efforts aimed at reducing the negative consequences of climate change. However, as our planet enters a period of changing climate never before experienced in recorded human history, interest is growing in the potential for deliberate intervention in the climate system to counter climate change. This study assesses the potential impacts, benefits, and costs of two different proposed classes of climate intervention: (1) carbon dioxide removal and (2) albedo modification (reflecting sunlight). Carbon dioxide removal strategies address a key driver of climate change, but research is needed to fully assess if any of these technologies could be appropriate for large-scale deployment. Albedo modification strategies could rapidly cool the planet’s surface but pose envi­ronmental and other risks that are not well understood and therefore should not be deployed at climate-altering scales; more research is needed to determine if albedo modification approaches could be viable in the future.



Support for this study is being provided by the following organizations and federal agencies. Funding from some sponsors supports specific topics related to the statement of task (indicated in italics):

  • BAND Foundation (impacts and risks on global ecosystems)
  • Department of Energy (research agenda)
  • John D. and Catherine T. MacArthur Foundation
  • National Academy of Sciences’ Arthur L. Day Fund
  • National Aeronautics and Space Administration (research agenda)
  • National Oceanic and Atmospheric Administration (research agenda)
  • V. Kann Rasmussen Foundation (research governance mechanisms)
  • Christopher Reynolds Foundation (research governance mechanisms)