This study aims to investigate effects of a treatment implemented in an environmental education course on pre-service elementary teachers’ environmental literacy and self-efficacy beliefs. During the course, 58 participants were informed about basic concepts of ecology, went to climate change exhibition, and prepared presentations and reflections about selected environmental problems. Scale of Self-Efficacy Belief towards Environmental Education and Scale of Environmental Literacy were used as pre- and post-tests. The participants’ reflections were analyzed to provide a deeper insight of their understanding of climate change. Results showed that the participants’ environmental attitudes, perception of environmental uses, and self-efficacy beliefs increased significantly, although there was no significant change in their environmental knowledge and concern at the end of the course. Analyses of their reflections indicated an improvement in understanding climate change. The article includes suggestions for overcoming limitations of the study.