The Potential Impacts of Climate Change on Maritime Boundaries and Exclusive Economic Zones, Three GIS scenarios for 20 jurisdictions in the western and central Pacific region

Abstract

Exclusive Economic Zones (EEZs) are maritime territories that extend 200 nautical miles from a country’s coastline. They mandate sovereign rights over all the natural resources. For Pacific island states, these zones support large economic sectors such as fisheries and tourism. The United Nations’ Convention for the Law of the Sea (UNCLOS) defines how EEZ territories are determined, but it is not explicit on whether changes to coastlines due to effects such as sea level rise could affect the delimitation of maritime boundaries and EEZs. The Pacific region is particularly vulnerable to climate change effects because of its many low-lying atolls. This study is the first which uses a scenario approach to quantitatively assesses the potential impacts of climate change on the shape, area, and connectivity of 20 jurisdictions’ EEZs in the western and central Pacific region. Due to competing legal arguments on whether and how climate change could affect the delimitation of EEZs, this study uses a scenario approach to capture the different legal interpretations of UNCLOS, and the potential development of international law. Based on a literature review and semi-structure interviews with legal scholars from the study region, three potential legal scenarios are developed. Scenario 1 assumes that EEZ boundaries are fixed regardless of changes in the coastline due to climate change effects unless they are provisional (i.e. disputed boundaries). Scenario 2 assumes that EEZ boundaries are also fixed unless all land in a jurisdiction is submerged due to sea level rise. Scenario 3 assumes that any EEZ boundaries change if their associated coastlines are submerged. Compelling arguments from the literature review and interviews provide credibility and legitimacy to each scenario in this study. GIS methods are applied to calculate new EEZs, change in boundary connectivity, and change in the area and shape of the high seas for each scenario in the study region. The results show that the total decrease in EEZ area for the study region would be 0.94% in scenario 1, 11.45% in scenario 2, and 41.48% in scenario 3. In terms of connectivity, of the 91 adjacent EEZ boundaries, two would be lost in scenario 1, 21 in scenario 2, and 37 in scenario 3. Because the GIS results and maps for each scenario varies significantly, I argue that the conceptualization of EEZ territories could increasingly result in contested and fuzzy spaces, especially as the impacts of climate change such as sea level rise intensify, and the question of the effects on maritime boundaries remains unresolved.