This paper considers how the school science curriculum can be conceptualised in order to address the contingent and complex nature of environmental and sustainability-related knowledge and understanding. A special concern lies in the development of research perspectives and tools for investigating ways, in which teachers are faced with complex and various situations in the sense-making of science-related issues, and subsequent pedagogic issues. Based on an empirical examination of Korean teachers' sense-making of their curricular practice, the paper develops a narrative approach to teachers' perspectives and knowledge by considering the value of stories as sense-making tools for reflective questioning of what is worth teaching, how and why. By employing the idea of "repertoire", the study regards teachers' stories about their environment-related personal and teaching experiences as offering angles with which to understand teachers' motivation and reflection in curricular development and implementation. Furthermore, three empirical cases present ways in which the nature of knowledge and understanding is recognised and potentially integrated into pedagogies through teachers' narratives. Finally, the paper argues for the need to reconsider the role of the science teacher in addressing environmental and sustainability-related issues, in ways that facilitate teachers' reflexive interpretation of meanings in cultural texts and the construction of pedagogic text. (Contains 5 notes and 2 tables.)