INTEGRATION OF EDUCATION FOR SUSTAINABLE DEVELOPMENT INTO SECONDARY SCHOOL CURRICULA: A REVIEW OF PEDAGOGICAL APPROACHES, TEACHER PREPAREDNESS, STUDENT ENVIRONMENTAL AWARENESS, BEHAVIORAL CHANGE OUTCOMES, AND CROSS-NATIONAL POLICY FRAMEWORKS

Abstract

The growing global concerns about climate change, environmental sustainability, and sustainable social development have made Education for Sustainable Development (ESD) a crucial part of secondary school curriculum reform. With a focus on pedagogical strategies, teacher readiness, student environmental awareness, behavioural change outcomes, and cross-national policy frameworks, this systematic review investigated the incorporation of ESD into secondary school curricula. 45 studies published between 2015 and 2025 that were gathered from databases such Scopus, ERIC, Springer, Taylor & Francis, Frontiers, MDPI, and Google Scholar were examined using the PRISMA framework. The results showed that 55.6% of the chosen papers were published between 2021 and 2025, demonstrating a sharp increase in sustainability education research after the Sustainable Development Goals (SDGs) were put into effect. The two regions that produced the most studies were Asia (35.6%) and Europe (28.9%). The most popular ESD strategy was multidisciplinary curricular integration (40.0%), which was followed by project-based learning (24.4%). To improve experiential learning and sustainability competencies, participatory and transformative pedagogies, such as community-based initiatives (28.9%) and outdoor learning (26.7%), were commonly used. Continuous professional development was shown to be the key tactic for enhancing sustainability teaching methods in 40% of the studies, indicating that teacher readiness continued to be a crucial element impacting ESD adoption. The review also demonstrated that ESD improved students' civic involvement, recycling habits, waste reduction strategies, environmental knowledge, and climate literacy. The most significant worldwide policy frameworks directing curriculum improvements for sustainability have been identified as SDG 4.7 and UNESCO initiatives. Effective ESD integration was however hampered by implementation issues such scarce resources, inadequate monitoring systems, and uneven regional support. Overall, the study shows that ESD considerably raises secondary school students' awareness of sustainability and encourages pro-environmental behaviour. It also emphasizes the necessity of greater institutional support, interdisciplinary curriculum changes, and sustained policy commitment for successful sustainability education