Because challenges to sustainability arise at the intersection of intertwined and evolving biophysical and sociopolitical systems, addressing complex and solution-resistant ("wicked") problems such as climate change, biodiversity loss, and management of shared and contested natural resources requires not only a scientific understanding of planetary systems, but also consideration of the human values, norms, and institutions that undermine sustainable ways of living. Geoscience educators who wish to integrate the topic of sustainability into their courses will naturally begin from their expert understanding of Earth systems, but may feel ill-equipped to teach the ethical, social, and political aspects of sustainability. A widespread lack of clarity about the fundamental nature of sustainability and its normative dimensions adds to the challenge. In this presentation we will draw on our respective disciplines of geology and philosophy to 1) outline a way to conceptualize sustainability that synthesizes scientific and ethical perspectives and draws on an approach developed for our book Living Well Now and in the Future: Why Sustainability Matters and 2) articulate four fundamental principles of sustainability ethics that follow from our analysis and core commitments of common morality. Violations of these principles will be illustrated with historical and contemporary examples including the Dust Bowl of the 1930s, hydro fracking, and the Flint water crisis. To help geoscience educators translate the outlined concepts and principles to classroom practice, we will also supply an overview of teaching resources and strategies, including the Teaching GeoEthics Across the Geosciences Curriculum" web site (http://serc.carleton.edu/geoethics/index.html, links to relevant case studies, and sample activities for engaging students in scientific and ethical inquiry around sustainability issues.