This paper reviews alternative (national and international) climate change mitigation policy instruments and interactions across them. Carbon taxes, cap-and-trade schemes, standards and technology-support policies (R&D and clean technology deployment) in particular are assessed according to three broad costeffectiveness criteria, their: i) static efficiency, defined to cover not just whether the instrument is costeffective per se but also whether it provides sufficient political incentives for wide adoption; ii) dynamic efficiency, which implies an efficient level of innovation and diffusion of clean technologies in order to lower future abatement costs; iii) ability to cope effectively with climate and economic uncertainties. Multiple market failures and political economy obstacles need to be addressed in order to meet these criteria. In this regard, carbon taxes or cap-and-trade schemes appear to perform better than alternatives. However, their cost-effectivenes can be enhanced through targeted use of other instruments. There is therefore room for climate policy packages.