The essay reviews the notion of "civic science" in global environmental governance and how it is articulated in international relations, science studies, democratic theory and sustainability science. Civic science is used interchangeably with participatory, citizen, stakeholder and democratic science, which are all catch words that signify various attempts to increase public participation in the production and use of scientific knowledge. Three rationales for civic science are identified: restoring public trust in science, re-orienting science towards coping with the complexity of environmental problems and installing democratic governance of science. A central proposition is that the promotion of civic science needs to be coupled with a theoretical understanding of its institutional, normative and epistemological challenges. The science-politics interface needs to be reframed to include the triangular interaction between scientific experts, policy- makers and citizens.