Sustainability at Sancta Maria International School is driven by meaningful, learner-led action. As part of the ISP Changemakers Green Horizons initiative, learners contributed to creating a more sustainable campus, achieving electricity savings of over 35,854 kWh between July 2024 and January 2025.The Smiley Earth Project brought together more than 2,500 learners, staff, and families, who pledged to switch off lights and air conditioners for ten minutes each day. This initiative strengthened self-leadership and interpersonal responsibility through simple, consistent action.In classrooms, the Indoor Green Plant Initiative improved air quality while encouraging inquiry-based learning, building cognitive and digital competencies. Learners also introduced water-saving aerators and developed a kitchen garden, fostering global awareness through everyday practices.These efforts have been recognised through the ISP Changemakers programme, highlighting the impact of learner-led initiatives. Through such experiences, learners continue to develop cognitive, digital, global, self-leadership, and interpersonal competencies as responsible, future-ready individuals.