This legal study is based on Legal Dimensions of Sea Level Rise: Pacific Perspectives which was published on June 29, 2021. The original version provided an assessment of key legal frameworks and policy questions that are relevant in the context of sea level rise in the Pacific region. This work, on the other hand, while largely based on the analysis of the original version, provides an updated assessment of the impacts of climate change, especially sea level rise, on the maritime rights of all island and coastal States. It is designed for a global audience. The study is divided into three parts. Part I looks briefly at the pioneering work of the Intergovernmental Panel on Climate Change (IPCC) and its most recent predictions for sea level rise during the current century, and then sets it in the context of other scientific work on threats from sea level rise and warming. Part II sets out an overview of relevant legal frameworks, key terminology, and principles based on international law, as well as judicial decisions and scholarly work that define the rights, resources, and obligations of all coastal States, particularly island and low-lying States. Part III then presents a series of responses to key legal and policy questions faced by these States in relation to sea level rise.