Proposed geoengineering interventions, like other high-stakes and potentially disruptive technologies, present both a compelling case for expanded research to inform future decisions, and significant concerns about societal harms that may follow from this research, directly or indirectly. In response, there have been widespread calls to both expand research and govern this research with greater care and scrutiny than typical of the normal processes that govern all research areas. We propose that for geoengineering and similarly controversial issues, governance of research must fulfill three broad functions. First, processes are needed that enable reliable research, by providing the authorization, resources, and management necessary for research to proceed, together with the strategic planning and quality controls to ensure that research results are useful and relevant to inform societal choices. Second, processes are needed to assess potential harms or risks from research activities and ensure that these are appropriately managed. These potential harms may include both direct physical risks, and indirect risks mediated by social, economic, or political processes. Finally, processes are needed to support the legitimacy of the research program, by ensuring that the topics, methods, and conduct are compatible with relevant legal, political, and moral principles and are broadly acceptable to affected citizens. These requirements may interact closely with the processes that serve the first two functions, by requiring that research priorities, aims, conduct, participants, and results are transparently and promptly disclosed, that relevant citizen and stakeholder groups are consulted, and that broader implications of proposed research are acknowledged and addressed. Drawing on the concerns expressed in the current geoengineering debate, and on experience conducting and governing research in other areas, we discuss alternative concrete ways to provide these functions for geoengineering research. This paper was prepared as input to a workshop of senior state officials considering the implications of potential geoengineering research for California.