Determining the Characteristics of Replacement Baseline Islands to Counter the Retreat of Indonesian Archipelagic Baselines as a Result of Climate Change

Global climate change has led to significant sea level rise and is directly affecting the existence of small islands in Indonesia's outermost regions. Several islands that served as baselines for the archipelago have shrunk with the potential to sink, threatening the validity of Indonesia's maritime claims under international law. The aim of this study is to identify the characteristics of replacement islands suitable to serve as new baselines to ensure the continuity of Indonesia's maritime borders. The methods used are descriptive and explanatory approaches, with spatial analysis based on geographic coordinate data and qualitative assessment based on Resource-Based Theory (RBT). The five main criteria used as reference include: (1) geographical proximity to the home island, (2) permanence and physical stability, (3) legal status, (4) strategic and defense value, and (5) conformity with the provisions of UNCLOS 1982 and national regulations. Based on these criteria, islands such as Sabang, Sekanak Raya, Kawio, Karatung and Raijua are proposed as potential replacements for the affected baselines. The results of the study show that a multidimensional approach based on RBT theory and spatial data can be a scientific and legal basis for the formulation of adaptive strategies for determining maritime baselines. This strategy is crucial to maintain the legitimacy, continuity and sovereignty of Indonesia's marine areas amidst the challenges of global climate change.