It is important to be able to make better informed decisions about issues such as sustainability and climate change that have both personal and global impact as early as possible in life. Primary teachers have a significant role in supporting students' learning and understanding of these concepts. One important teaching skill that needs to be improved for understand sustainable development is the creation of meaningful generalizations, including models. Therefore, the learning experiences of pre-service primary teachers (N = 28) in regard to modelling was our focus. The results of our case study indicated concrete and visual modes as most common in student teachers' experiences and understandings of modelling. The symbolic mode is less in evidence and an understanding of gestural and verbal models is rather unambiguous. Thus, we see a need and the potential to improve teaching and learning experiences in teacher education about the modelling of complex concepts.