This project will develop a world social-ecological model to realize marine plastic pollution-free ocean by adopting input-output/system dynamics (IO/SD) modeling method by Dr. M. Cordier and Dr. T. Uehara. Because of the high uncertainty involved in the information about the impacts of marine plastic pollution, they employ  participatory modeling by combining the IO/SD modeling method with the Delphi method which uses an iterative questionnaire survey to glean the information from experts. The objectives of the project are to develop a world social-ecological model, develop qualitative scenarios, and validate teh scenarios quantitatively by using teh model and elicit desirable world social-ecological system and transition paths towards its realization. Additionally, we also intend to strengthen the international  collaboration through the project such as from an individual collaboration to an organizational-level collaboration.