Coupling the study of sustainability with geoscience may enable students to explore science in a more sophisticated way by examining the social–technological–ecological relationships that exist between human–nonhuman and flora–fauna–land interactions. Elementary educators are a population capable of making these issues come to life for today's youngest citizens, who will ultimately become tomorrow's changemakers. This study explores Sustainability Science for Teachers, a semester-long hybrid course designed to enable future teachers to engage in sustainability and science concepts while developing their understanding of science from the human perspective and in which an issues-based curriculum underpins social and biosphere responsibility. The course's Water unit is explored as a case study of the melding of sustainability and geoscience to engage teachers in a more nuanced understanding of science education. The unit's curriculum is presented and its design process is explained, followed by a cross-sectional analysis of student outcomes. Data from preservice teachers enrolled in the course, as well as course alumni, were collected over a 4-y period. A mixed methods evaluation of teachers' opinions and products indicate that the Water unit facilitated the development of new understanding and new ways of thinking about teaching their future students. Opportunities and challenges for fusing the geosciences, sustainability concepts, and preservice teacher education in a novel and impactful fashion are discussed.