How to Start Governing R&D to Mitigate Solar Radiation

Solar radiation mitigation (SRM) is a geoengineering strategy that could reduce global average temperatures. Congress should appoint an oversight committee and begin to fund R&D.

The world is not making sufficient progress in reducing greenhouse gas emissions to avoid debilitating climate damage. As a result, interest among decisionmakers and scientists has grown in geoengineering—human intervention in the global climate system—as a climate control mechanism. Solar radiation mitigation (SRM), because it likely can be deployed (relatively) cheaply and rapidly, receives greatest attention. One approach to SRM would lower global average temperature by lofting millions of tons of sulfur into the upper atmosphere that turn into sulfate ions and reflect a small portion of incoming solar radiation back into space.

The present level of knowledge about SRM climate risks and the design, operation, and cost of a deployable SRM system is inadequate for even beginning to assess any possible future role for SRM.

There is no deployed SRM system, and scant research and development has been done to understand the very considerable uncertainties in magnitude of its impacts, duration, and reversibility. Little is known about many SRM potential climate impacts such as ocean acidification, ozone depletion, effect on precipitation, regional climate variability, and consequences of rapid termination of the efforts. Thus far, essentially all technical SRM R&D has been done in laboratories on physical models, and experts agree that substantial controlled, atmospheric experiments are needed to validate reflective particle architecture, efficient mechanisms for injecting particles into the atmosphere, duration and distribution of cooling, and other unanticipated effects, not to mention cost. Collecting and interpreting SRM experimental data will be a slow process because it requires attribution of climate effects in the presence of natural variability and feedbacks.

One view is that there is an urgent need to undertake R&D to obtain as much information as possible to inform assessment of whether the benefits outweigh the risks of deployment—a judgment that depends on the severity of climate change and the benefits and costs of alternative climate-control mechanisms. The opposing view is that any R&D on SRM presents a moral hazard that cheap but risky SRM will crowd out less risky, but more expensive, emission-reduction efforts. Opponents stress that there is no governance system to control who will have access to planning and participation in SRM R&D, or in decisionmaking on possible deployment. Up to the present, the understandable caution of public and environmental leaders to encourage human intervention in the climate has kept federal support of SRM (and other solar geoengineering options) very low. The federal budget does not have a line item for SRM R&D, but we estimate that total expenditures are less than $10 million per year.

Current uncertainties, combined with the strong and well-defended opinions both for and against SRM as a potential tool for combatting climate change, dictate that all decisions about the potential deployment of SRM technologies, and even the future course of SRM R&D itself, would necessarily be provisional and subject to change.

We believe the United States should launch an SRM R&D program (one can imagine including other solar geoengineering projects as well) at an initial funding level of $50 million per year. Such funding could support 10 to 15 university-based SRM research centers at a level of $2–$3 million per year, selected on a competitive basis, and augmented by conferences and studies to engage a variety of stakeholders. These funds should be provided by the National Oceanic and Atmospheric Administration, the National Aeronautics and Space Administration, and the Department of Energy, and funds should be newly appropriated, not reprogrammed from existing research efforts. The SRM R&D technical program should be formulated within the context of broad climate change research. Formal international collaboration should be considered after the United States’ SRM R&D effort has been established and has two or three years of operating experience.

Congress should meanwhile establish an independent, blue-ribbon SRM Oversight Committee accompanying this R&D effort, empowered to monitor all aspects of federally supported activities and mandated to submit an annual report to Congress on progress in narrowing key uncertainties and quantifying risks. This independent committee (administratively housed in NOAA, NASA, or DOE) would not have its agenda set by the agencies funding geoengineering R&D. To assure transparency, like all other federal advisory committees, it would be subject to the Federal Advisory Committee Act of 1972. It would not have the authority to cancel or modify the congressionally approved R&D program. Members would be nominated by the president and confirmed by the Senate. 

The purpose of this oversight committee would be to communicate to Congress, and therefore to the public, about progress being made in federal R&D programs to validate the cost and performance of SRM, and narrow uncertainty about potential adverse impacts. The SRM Oversight Committee would serve as an initial, “soft,” transparent technology governance step.

An independent blue-ribbon oversight committee, operating transparently and with accountability to Congress, can provide a soft approach that provides a mechanism for discussion between SRM advocates and skeptics, while researchers accumulate sufficient knowledge to justify hard decisions about if, how, and when to pursue this technology. 

The proposed oversight committee should not be expected to succeed in resolving the differences between geoengineering proponents and opponents. But similar initiatives related to nuclear power suggest that substantive progress is possible. For decades the public has been concerned that the government’s commercial nuclear power R&D and licensing programs paid insufficient attention to the issues of reactor safety, radioactive waste management, and nuclear proliferation. Congress’s establishment of the Nuclear Regulatory Commission’s Advisory Committee on Reactor Safety and DOE’s Nuclear Energy Research Advisory Committee has reduced public unease by increasing transparency and providing legitimate avenues to raise and deliberate on technical and policy issues.

The present level of knowledge about SRM climate risks and the design, operation, and cost of a deployable SRM system is inadequate for even beginning to assess any possible future role for SRM. Current uncertainties, combined with the strong and well-defended opinions both for and against SRM as a potential tool for combatting climate change, dictate that all decisions about the potential deployment of SRM technologies, and even the future course of SRM R&D itself, would necessarily be provisional and subject to change. An independent blue-ribbon oversight committee, operating transparently and with accountability to Congress, can provide a soft approach that provides a mechanism for discussion between SRM advocates and skeptics, while researchers accumulate sufficient knowledge to justify hard decisions about if, how, and when to pursue this technology. 

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Cite this Article

Deutch, John, and Maria T. Zuber. “How to Start Governing R&D to Mitigate Solar Radiation.” Issues in Science and Technology (January 14, 2021).