This report aims to make a contribution to the discussion on how both the prevailing climate and potential nuclear threats may interact with each other. Despite an increased understanding of the climate and nuclear threat and a growing urgency for action on both fronts, little attention has been given to how they may interact with each other. This updated report considers how both threats can have grave implications for global and human security and how they may exacerbate other crises in interacting together. It further examines the possible effects of nuclear explosions on the climate, as well as the consequences of climate change and extreme weather events on nuclear security. The report also exposes the pitfalls of including nuclear energy as an alternative to fossil fuels to curb climate change, and the nuclear weapon-proliferation risks of nuclear energy programmes. Finally, it reviews mechanisms and initiatives to neutralize both threats and considers how success in one area could benefit action in the other.