	Substantial Uncertainties Remain Regarding Geoengineering Approaches and Their Potential Effects

Substantial questions remain on the efficacy and potential environmental  impacts of proposed geoengineering approaches, in part, because  geoengineering research and field experiments to date have been limited. According to recent studies,  much of the research into SRM approaches to date has been limited to  modeling studies to assess the effects of either injecting sulfur aerosols  into the stratosphere or brightening clouds to reduce incoming solar  radiation at the earth’s surface and produce a cooling effect. One expert familiar with these  experiments noted that, while they improved scientific understanding of  the role of iron in regulating ocean ecosystems and carbon dynamics, they  were not specifically designed to determine the implications of ocean  fertilization with iron as a geoengineering approach for large-scale  removal of carbon dioxide from the atmosphere. Due to the limited amount of geoengineering research conducted to date,  the experts we interviewed stated that a sustained program of additional  research would be needed to address the significant uncertainties  regarding the effectiveness and potential impacts of geoengineering  approaches. Due to the potential for disparities in environmental outcomes from using  these technologies—similar to the expected regional variation in climate  change impacts—experts that we spoke with said that the political,  ethical, legal, and economic issues surrounding the potential impacts of  geoengineering technologies warranted close examination. Federal Agencies Have Sponsored Some Research Activities, but These Activities Are Not Part of a Coordinated Federal Geoengineering Research Strategy

Our observations to date indicate that federal agencies such as DOE,  National Science Foundation (NSF), U.S. Department of Agriculture  (USDA), and others have funded some research and small-scale  technology testing relevant to proposed geoengineering approaches on an  ad-hoc basis. For CDR approaches, DOE has sponsored research  in both land-based and ocean-based carbon storage, including small-scale  demonstration projects of geological sequestration as part of its Regional  Carbon Sequestration Partnerships. In addition to these efforts, federal officials noted that a large fraction of  the existing federal research and observations on basic climate change  and earth science could be relevant to improving understanding about  proposed geoengineering approaches and their potential impacts. Staff from federal offices coordinating the U.S. response to climate  change—CEQ, OSTP, and USGCRP—stated that they do not currently  have a geoengineering strategy or position. In the event that the federal government decides to fund a coordinated  geoengineering research strategy, our review of relevant studies and  interviews with experts to date identified some key factors for  policymakers to consider when designing a federal strategy for  geoengineering research. Recent GAO work offers insights on key considerations for assessing risk  and managing technology-based research programs. Existing Federal Laws and International Agreements Could Apply to Certain Geoengineering Activities, but Regulatory Gaps Remain

Existing federal laws and international agreements were not enacted or  negotiated with the purpose or intent to cover geoengineering activities,  but according to legal experts and federal officials, several existing federal  laws and international agreements could apply to geoengineering research  and deployment, depending upon the type, location, and sponsor of the  activity. Domestically, however, interviews with agency officials to date  and our past work indicate that federal agencies have not yet assessed  their statutory authority to regulate geoengineering activities, and those  that have done so have identified regulatory gaps. Although some geoengineering approaches, such as geological  sequestration of carbon dioxide in underground formations, would not  involve international agreements because the activities and their effects  would be confined to U.S. territory, other SRM and CDR approaches  would. Our initial work  indicates that parties to two international agreements have taken action to  address geoengineering activities, but it is still uncertain whether and how  other existing international agreements that legal experts have identified  as potentially relevant could apply to geoengineering. The scientific and policy experts we spoke with largely echoed the same  themes and issues that the legal experts raised. Interviews with scientific  experts to date suggest that governance issues related to geoengineering  research with the potential for transboundary impacts should be  addressed in a transparent, international manner in consultation with the  scientific community. This is a work of the U.S. government and is not subject to copyright protection in the  United States.
Why GAO Did This Study

Key scientific assessments have underscored the urgency of reducing emissions of carbon dioxide to help mitigate potentially negative effects of climate change; however, many countries with significant greenhouse gas emissions, including the United States, China, and India, have not committed to binding limits on emissions to date, and carbon dioxide levels continue to rise. Recently, some policymakers have raised questions about geoengineering--large-scale deliberate interventions in the earth's climate system to diminish climate change or its potential impacts--and its role in a broader strategy of mitigating and adapting to climate change. Most geoengineering proposals fall into two approaches: solar radiation management (SRM), which offset temperature increases by reflecting a small percentage of the sun's light back into space, and carbon dioxide removal (CDR), which address the root cause of climate change by removing carbon dioxide from the atmosphere. Today's testimony focuses on GAO's preliminary observations on (1) the state of the science regarding geoengineering approaches and their effects, (2) federal involvement in geoengineering activities, and (3) the views of experts and federal officials about the extent to which federal laws and international agreements apply to geoengineering. To address these issues, GAO reviewed scientific literature and interviewed federal officials and scientific and legal experts.

What GAO Found

Substantial uncertainties remain on the efficacy and potential environmental impacts of proposed geoengineering approaches, because geoengineering research and field experiments to date have been limited. GAO's review of relevant studies and interviews with experts to date found that relatively few modeling studies for SRM approaches have been published, and only limited small-scale testing--primarily of carbon storage activities relevant to CDR approaches--have been performed. Consequently, the experts GAO spoke with stated that a sustained effort of coordinated and cooperative research would be needed to determine whether proposed geoengineering approaches would be effective at a scale necessary to reduce temperatures and to attempt to anticipate and respond to potential unintended consequences--including the political, ethical, and economic issues surrounding the use of certain approaches. Specifically, just as the effects of climate change in general are expected to vary by region, so would the effects of certain large-scale geoengineering efforts, therefore, potentially creating relative winners and losers and thus sowing the seeds of future conflict. Federal agencies have funded some research and small demonstration projects of certain technologies related to proposed geoengineering approaches; but these efforts have been limited, fragmented, and not coordinated as part of a federal geoengineering strategy. Officials from interagency bodies coordinating the federal response to climate change stated that their offices (1) have not developed a coordinated research strategy, (2) do not have a position on geoengineering, and (3) do not believe is it necessary to coordinate efforts due to the limited federal investment to date. In the event that the federal government decides to expand geoengineering research, GAO's interviews with experts suggest that transparency and international cooperation are key factors for any geoengineering research that poses a risk of environmental impacts beyond our borders. Further, GAO's past work indicates that a comprehensive assessment of costs and benefits that includes all relevant risks and uncertainties is a key component in strategic planning for technology-based research. According to legal experts and federal agency officials, some existing federal laws and international agreements could apply to geoengineering research and deployment. However, some federal agencies have not yet assessed their authority to regulate geoengineering, and those that have done so have identified regulatory gaps. Although legal experts have identified some relevant international agreements and parties to two agreements have taken actions to address geoengineering, it is not certain whether and how other agreements would apply. Most scientific and legal experts GAO spoke with distinguished the governance of research from governance of deployment and noted that governance of geoengineering research with transboundary impacts, such as SRM approaches, should be addressed at the international level in a transparent manner and in consultation with the scientific community. However, the experts' views on the details of governance varied.