This article discusses the development of an online e-seminar that uses a geographic information system as the basis for its major activities. Students of the seminar explore the concept of environmental sustainability in a conference-style format with the perspectives of nine Columbia University faculty members affiliated with the Center for International Earth Science Information Network. Students experience innovative presentations from each faculty member, participate in online forums, and complete online activities using a customized mapping tool with data from the Environmental Sustainability Index. The activities are designed to engage the student as an active participant in exploring environmental sustainability.