Technologies for mitigating and adapting to climate change are inherently political. Their development, diffusion, and deployment will have uneven impacts within and across national borders. Bringing the governance of climate technologies under democratic control is imperative but impeded by the global scale of governance and its polycentric nature. This paper draws on innovative theorising in the deliberative democracy tradition to map possibilities for global democratic governance of climate technologies. It is argued that this domain is not beyond the reach of democracy. Civil society has a unique and expanded role to play in generating democratic legitimacy by fostering public deliberation; translating and transmitting concepts, ideas, and messages; and promoting and facilitating deliberative accountability.