The international governance of asylum requires states to cooperate to provide the public good of humanitarian protection. The need to establish responsibility-sharing resembles the collective action problem in climate change mitigation. While there is a general consensus on the differentiation of state responsibilities in most environmental agreements, states continuously fail to progress on responsibility-sharing in asylum governance. In this article, we compare the collective action challenges in asylum to those in climate governance and identify the similarities and differences in their characteristics as public goods. We then discuss the principle of “common but differentiated responsibilities” that guides global climate change mitigation and demonstrate how equity principles can be applied to differentiate state responsibilities in the context of humanitarian protection. The subsequent analysis of recent efforts to establish effective responsibility-sharing reveals the trade-offs involved in the design of a responsibility allocation mechanism for refugee protection. Our findings provide important lessons for the prospects and limits of responsibility-sharing in asylum governance.