An interval-valued Pythagorean fuzzy set-based multi-criteria decision-making model for evaluating decarbonization criteria in maritime transport

Decarbonization in maritime transport has become an increasingly important strategic issue in response to growing environmental pressures, expanding regulatory obligations, and the sector’s need for transformation. This process, however, goes beyond technical innovation or the adoption of alternative fuels alone. It also requires a broader assessment of multiple factors such as infrastructure adequacy, energy management, emissions monitoring, operational feasibility, and institutional preparedness. The aim of this study is to identify the relative importance of the criteria affecting the decarbonization process in maritime transport through the Interval-Valued Pythagorean Fuzzy Analytic Hierarchy Process (IVPF-AHP) method. Based on the evaluations of five experts with relevant field knowledge, a multi criteria decision model was developed and the criteria were analyzed according to their order of priority. The findings show that decision makers assign the greatest importance to low carbon equipment, shore power, emissions measurement and reporting, fleet modernization, and energy monitoring and management systems. By contrast, social responsibility, training and awareness, and regulatory compliance received lower weights. The results indicate that decarbonization in maritime transport cannot be understood simply as a matter of seeking alternative technologies. Rather, it requires a comprehensive transformation approach that brings together feasible technical investments and measurable performance mechanisms. The study is expected to contribute to the literature by offering a holistic prioritization framework that takes uncertainty into account and by providing decision support for sector practitioners.