Small island developing states (SIDS) are a unique group of countries that bear a disproportionate share of the impacts of climate change despite their minimal contribution to its causes. Their vulnerability and lack of resources to adapt raise significant questions for global security and justice in the decades ahead. This policy brief reviews both the challenges that SIDS face because of climate change in terms of adaptation and development, internal displacement and migration, sovereignty and exclusive economic zones, as well as the means they use to advance their cause, such as legal claims to compensation and multilateral diplomacy. The policy brief proposes an agenda for action that identifies political, legal, economic, and other possible ways of addressing the predicament of the SIDS. The authors encourage policymakers to consider the proposals presented here at fora such as the upcoming Third International SIDS Conference, UNFCCCnegotiations, other climate summits and discussions on a post-2015 sustainable development framework, with a view to taking concrete decisions for action.