This study is an implementation one that analyzed the development and operation of the 2022 high school credit system Suncheon leading district region-specific joint curriculum, ‘Ecology and Environment,’ by the Ministry of Education’s high school credit system leading district joint curriculum promotion task. We analyzed and presented the characteristics of the overall curriculum operation, including the function of the regional cooperative body for the operation of the region-specific joint curriculum in Suncheon leading district, the development process of the region-specific curriculum, establishment of achievement standards and composition of detailed contents, and class and evaluation methods. The region-specific curriculum ‘Ecology and Environment’ focuses on climate change, a global environmental issue, and is primarily operated based on a problem- or project-based learning that utilizes the Suncheon Bay Wetland, the region’s most significant ecological resource. We found that students’ overall satisfaction after class was very high at 4.67 points out of 5. As a result of detailed analysis using the Likert scale, changes in students’ environmental awareness, environmental knowledge, environmental attitude, and environmental interest increased from 4.08, 3.17, 4.07, and 3.85 points before class to 4.81, 4.50, 4.61, and 4.68 after class, respectively, suggesting that the educational effect was very high. This study also presents the qualitative improvements for the operation of the region-specific joint curriculum in the high school credit system leading district through content analysis of FGI (Focus Group Interview) of four experts, including teachers, school inspectors at the Office of Education, and an educational researcher, who participated in the overall curriculum operation from the curriculum development stage to completion of its operation.