In this paper we argue that recent policy treatments of solar radiation management (SRM) have insufficiently addressed its potential implications for contemporary political systems. Exploring the emerging ‘social constitution’ of SRM, we outline four reasons why this is likely to pose immense challenges to liberal democratic politics: that the unequal distribution of and uncertainties about SRM impacts will cause conflicts within existing institutions; that SRM will act at the planetary level and necessitate autocratic governance; that the motivations for SRM will always be plural and unstable; and that SRM will become conditioned by economic forces.