The thematic dossier ‘Climate and Security’ presents a compilation of articles that are diverse yet orientated around these two conceptual axes. Given the relevance and topicality of this thematic relationship, some articles draw on theoretical and methodological approaches framed by the schools of International Relations, while others present analyses based on case studies. The challenges facing Small Island Developing States in the face of rising sea levels are discussed, with particular reference to the South Pacific islands, but also the relationship between climate change, security and conflicts in the context of the Arctic, sub-Saharan Africa and the South Atlantic. Other topics are analysed, such as the problem of political instability in the face of the increase in social problems aggravated by extreme climatic events, and emerging issues such as underwater infrastructures and cyberspace.