<![CDATA[Background: In science education, fostering students’ self-awareness and environmental responsibility is essential for developing sustainable character and ecological consciousness. However, many science learning practices still emphasize conceptual understanding and academic achievement rather than engaging students in authentic environmental problem-solving activities. Consequently, innovative instructional approaches are needed to encourage students’ active participation and strengthen their environmental responsibility through meaningful learning experiences. Aims: This study aimed to examine the effectiveness of Project-Based Learning (PjBL) in enhancing students’ self-awareness and environmental responsibility at SMP Muhammadiyah 13 Surabaya. Method: This study employed a quantitative quasi-experimental design using a pretest–posttest control group approach. The reliability of the research instrument was tested using Cronbach’s Alpha, resulting in a coefficient of 0.90. The collected data met the assumptions of normality and homogeneity prior to hypothesis testing. Data analysis was conducted using paired sample t-tests and independent sample t-tests. Results: The findings demonstrated that students in the experimental group showed significantly higher improvement than those in the control group, with a significance value of 0.000 (p < 0.05). The experimental group achieved a mean score difference of 6.373 points higher than the control group. Furthermore, the implementation of PjBL increased students’ self-awareness by 0.51 points and environmental responsibility by 0.63 points. Conclusion: Project-Based Learning effectively promotes students’ reflective abilities and environmental responsibility in science education. The findings suggest that contextual project-based activities can support the development of environmentally conscious and socially responsible students in modern educational settings.]]>
