Teachers do not simply deliver a set curriculum, but carry out classes based on practical knowledge, including their values, beliefs, and experiences. Therefore, it is meaningful to investigate the practical knowledge of teaching among teachers in terms of orientation, structure, and content in order to understand the teacher's knowledge, conflicts, and trial and error experiences in the classroom. In this study, we explored the practical knowledge of a teacher conducting SSI-STEAM classes themed on climate change. In the specific context of SSI-STEAM classes, it was possible to understand how the teacher organized climate change classes and guided the actions of students in action-oriented classes. In addition, we expect that this study, which examines the practical knowledge of a novice teacher, will serve as the first step in narrowing the gap in SSI-STEAM education between pre-service teacher education and actual school classroom experience.