Rising waters, shrinking states: the potential impacts of sea level rise on claims to maritime jurisdiction

Global sea levels are rising and this trend has been linked to anthropogenically-induced climate change. This phenomenon has raised concerns over a range of threats to coastal States and coastal-dwelling populations. While this paper reviews these issues, its main focus is on the potential implications of sea level rise on national claims to maritime jurisdiction. Such claims are generally measured from baselines along the coast. The paper examines, in particular, the predominant type of baseline used by coastal States, that is, normal baselines coinciding with low water lines along the coast. The traditional implication of using the low-water line as the basis for measuring maritime claims is that as the low water line along the coast changes or ambulates, so too will the maritime limits measured from it. As sea levels rise, normal baselines are likely to retreat inland leading to potentially substantial losses in the areas of nationally-claimed maritime spaces. Options to preserve the maritime claims of coastal States threatened by sea level rise are explored. It is argued that there is a growing need for a departure from the traditional norm of ambulatory normal baselines and consequently shifting maritime jurisdictional limits in the interests of providing marine users with stability, clarity and certainty