Environmental Education Across the Curriculum: Challenges of Integration in the Turkish Educational System

Sustainable environmental education (SEE) is a foundational element in aligning national curricula with global sustainability goals. This study examines the extent to which both SEE concepts—such as environmental awareness, energy conservation, recycling, and eco-friendly practices—and broader sustainable environment (SE) concepts—such as green finance, renewable energy, and carbon emission reduction—are integrated into the Turkish National Curriculum from preschool through high school. Through a systematic curriculum analysis supported by an extensive literature review, this study identifies significant variation in the distribution of sustainability-related themes across grades and subjects. Our findings highlight a notable concentration of SEE content in upper-secondary science-based subjects, while early childhood education and humanities disciplines show limited integration. This uneven distribution suggests differences in the curricular emphasis placed on sustainability-related themes across educational stages and disciplines. The findings support the value of a more holistic and interdisciplinary curriculum approach, beginning in early education, to strengthen the curricular integration of sustainability-related themes and better align educational content with sustainable development goals.