Education has responded to global Sustainable Development (SD) goals by drawing on a range of issuerelated, context-based, and cross-curricular approaches to teaching SD. This paper aims to examine how teachers describe the content in SD and how they justify this content concerning their teaching practice. The Pedagogical Content Knowledge (PCK) framework, with its reflective tool Content Representation (CoRe), was used in combination with semi-structured interviews to capture 18 Swedish upper-secondary science teachers’ reflections. The results indicate four themes of content that the teachers emphasise: energy and global warming, ecosystem services and biodiversity, presence of harmful substances and materials in nature, and imbalance of natural substances in nature. The teachers justified these content themes in terms of the importance of students’ gaining different perspectives (local, global, ecological, social, and economic), belief in the future, action competence, and general scientific education. The paper contributes to sustainability education research, as it focuses on teaching sustainability in the light of the PCK framework. Also, it can support and inspire teachers when they decide what content to include when teaching SD. © 2024 University of Oslo, Norwegian Centre for Science Education. All rights reserved.

This study focuses on how science teachers' Pedagogical content knowledge (PCK) can be captured and developed with the support of Content representation (CoRe) in combination with video-based reflection when they plan, teach, and reflect on their teaching in sustainable development (SD). The theoretical framework is based on PCK, and the Refined consensus model (RCM) is used as a theoretical lens for conceptualising links between teaching practice and PCK development. Eleven upper-secondary school science teachers participated in the study. Data from two teachers were chosen to illustrate representative examples from the analysis. The findings indicate that the use of CoRe and video-based reflection provides opportunities for teachers to make their knowledge of practice explicit and help them begin to identify aspects within their own practice that are important for the further development of teaching SD. The use of RCM as an analytical tool also makes an important contribution to how RCM can be used to identify and capture teachers' PCK.

The pursuit of sustainable development is a necessity for life on Earth and the future of humanity. Education is important in this endeavour; therefore, creating knowledge about teachers' teaching for sustainable development is essential. This study aimed to investigate how Swedish upper secondary science teachers adjust their teaching of the environmental dimension in sustainable development to the different vocational education programmes their students attend. Data were collected through individual semi-structured interviews with 15 in-service science teachers and analysed by thematic coding. The result showed that most teachers (but not all) adjusted their teaching to the students' vocational educational programme; however, they did it to different extents and in different ways. The result presents teachers' descriptions of and arguments for adjusting their teaching linked to the pedagogical content knowledge (PCK) framework. The PCK framework is used as a theoretical lens in this study. Further research is needed to investigate how science teachers' adjustments to students' vocational education affect the students' knowledge of the environmental dimension in sustainable development and how that affects actions in their future professional life.

It is vital that upper secondary students gain a rich and deep knowledge of sustainability issues, as they will enter adulthood and working life within a short time. The students belong to a generation that will be intensely involved in managing several environmental issues to achieve sustainable development for our Earth. However, earlier research indicates that many teachers have a low self-efficacy for teaching sustainability issues. This study aimed to explore how science teacher teams in Swedish upper secondary schools can develop their knowledge and expertise in sustainable development (SD) through collective reflections with the support of the reflective tool Content Representation (CoRe). Science teachers' pedagogical content knowledge (PCK) development in teaching SD was examined. Twelve in-service science teachers participated in the study. The qualitative research design included semi-structured interviews and science teacher teams' collective meetings. The findings covered four themes about how the collective reflections with support of the CoRe tool stimulated teachers' PCK development: (1) creating structure and a focus for learning conversations, (2) modification of the teaching approach, (3) development of new content knowledge and pedagogical knowledge in SD, and (4) shared language to stimulate equal opportunities for students to learn SD. The conclusion is that with the support of CoRe, the teacher team's collective PCK in SD was developed; therefore, we recommend that decision-makers within the school system organize regular meetings in science teacher teams and introduce CoRe to the teachers.