To determine whether innovations in policy concerning climate-change mitigation are symbolic or truly radical in the sense of 'tipping' existing policy portfolios towards a new instrumental logic, we study policy innovations in the context of pre-existing policy portfolios and analyse the associated dynamics over time. Our analysis is facilitated by a new measurement of policy output, the Index of Climate Policy Activity. This new approach sheds light on the relative importance of policy innovations in complex policy portfolios, and serves as a blueprint for further analyses of the politics of policy innovation. Empirically, we analyse policy innovations within the policy portfolios of energy production in Austria, Germany, and the UK between 1998 and 2010. We find high stability in the instrumental logic but substantial change in policy settings and calibrations.