COIL+: enhancing sustainability competencies in higher education through experiential and problem-based learning

Purpose This paper aims to investigate the efficacy of COIL+, a hybrid pedagogical model integrating virtual collaboration and field immersion, in enhancing sustainability competencies among higher education students. It also aims to assess how COIL + fosters transformative learning and sustained behavioral change aligned with Education for Sustainable Development (ESD) goals. Design/methodology/approach A mixed-methods approach was employed, combining pre- and post-program surveys, reflective journals, field assessments and nine-month follow-up interviews. Conducted with 19 students from Japan and South Korea in FY2022, the study leverages Experiential Learning Theory (ELT) and Problem-Based Learning (PBL) to evaluate outcomes across virtual and field phases (e.g. the Bay Wetlands in South Korea). Findings COIL + significantly improved sustainability attitudes (M = 3.2–4.1, Cohen’s d = 1.14) and behavioral intentions, with 70% of participants sustaining actions (e.g. composting) nine months post-program. Cultural differences enriched engagement, with field immersion amplifying practical application of SDG-related skills (e.g. SDGs 11, 13, 15). Research limitations/implications The cohort size was modest (n = 19), and analytic n varied by instrument due to occasional missing responses; therefore, generalizability is limited. The absence of a control group also constrains causal inference, and planned expansions to 100 + participants in 2025 will help strengthen robustness. Practical implications COIL + offers a scalable, cost-effective framework for embedding sustainability in curricula, fostering global competencies and actionable change. Social implications COIL+ demonstrates that hybrid experiential learning can cultivate sustainability-oriented behaviors that extend beyond the classroom and persist in students’ everyday lives. By fostering intercultural collaboration between students from Japan and South Korea, the program builds cross-cultural understanding as a foundation for collective action on global sustainability challenges. The alignment of student-driven projects with the SDGs suggests that this model supports not only individual behavioral change but also broader civic engagement — equipping students to contribute meaningfully to sustainable communities across diverse cultural and institutional contexts. Originality/value This study uniquely integrates virtual and field-based learning, demonstrating COIL+’s potential to bridge theory and practice in ESD.