Developing youth action competence through school–community environmental projects for adaptive sustainability action

Developing young people’s capacity to address sustainability challenges requires more than fostering environmental awareness or encouraging predetermined pro-environmental behaviors. While action-oriented sustainability education increasingly emphasizes authentic participation, less is known about how students develop the capacity for meaningful sustainability action through real-world practice. This study examines how action competence developed among 19 Thai secondary school students participating in learner-driven school–community environmental projects addressing waste-related sustainability challenges. Using a qualitative interpretive design within an action research framework, data were generated through an action competence self-assessment questionnaire administered at three time points, reflective writings, student artifacts, and researcher fieldnotes across a 16-week extracurricular program. Descriptive findings showed an upward shift in students’ self-assessed action competence over time. Qualitative analysis revealed that development was neither linear nor attributable to participation alone. Students initially proposed technically plausible but limited responses, which evolved into more preventive, context-responsive, and collaboratively negotiated forms of sustainability action. Action competence became most visible when students encountered practical constraints, stakeholder expectations, and unforeseen implementation challenges requiring them to revise assumptions, negotiate alternatives, and sustain collective action under uncertainty. These findings advance understanding of action competence as a context-dependent capacity that develops through iterative negotiation, adaptive decision-making, and engagement with real-world uncertainty, rather than through participation alone. For sustainability education, this highlights the importance of learning environments that enable students to exercise judgment, negotiate with others, and revise purposeful action as social and practical conditions change.