Climate change adaptation is a notorious example of a wicked problem. Teachers need to have extensive knowledge to design high-quality education that addresses the wickedness and contributes to wicked problem-solving. The components of the knowledge basis for teaching climate change issues can be highlighted with the Pedagogical Content Knowledge (PCK) framework. In the international, interdisciplinary course EduChange, pre-service teachers built their content knowledge and pedagogical content knowledge. They took part in a training week, where they explored issues related to climate change in different regions, acquainted themselves with place-based education and fieldwork, and were trained in educational design. Subsequently, they developed lessons for secondary schools. This paper describes the structure of the course, and explores how it contributed to the development of the PCK of the pre-service teachers. Survey data and interviews show that the participants valued the course. Although the pre-service teachers said the course contributed considerably to the development of their PCK, the lessons developed varied in respect to the wicked characteristics that were addressed and their potential for stimulating progression in wicked problem-solving.