Abstract At present there is no binding agreement (at a global level) to address the risk of anthropogenic climate change after 2012. Disagreements abound with respect to a post-2012 climate change agreement, on issues such as economic development, policy criteria, environmental effectiveness, cost-effectiveness, equity, dynamic flexibility, complementarity, enforceability and so on. One such disagreement is whether or not nuclear power should play a role in a post-2012 climate change agreement. This qualitative analysis explores the conditions under which nuclear power could contribute to addressing climate change in post-2012 architectures. It reveals that – given the right framework conditions – some architectures, like ‘cap and trade’ regimes or ‘policies and measures’ can improve the competitiveness of nuclear power plants, while others are unlikely to provide incentives for nuclear energy development in the short to medium term, such as adaptation and technology cooperation. Overall, the study concludes that post-2012 climate change policy should aim at providing policy flexibility without compromising technology flexibility. For example, the provision of long-term commitment periods has the potential to enable better investments in existing low-carbon technologies but stifle the policy flexibility that political decision makers are often keen to retain so that they can respond more quickly to new scientific evidence or advances in clean technology development.