Teaching environmental sociology to undergraduates can be challenging, because they don't always understand the link between environmental cases and sociological theories. In addition, students may or may not have taken an introductory sociology course, and /or are coming from STEM, so the ideas presented need to cover basic sociological concepts and theories in a way that is accessible to non-social science majors. Twenty Lessons in Environmental Sociology takes a sociological rather than an environmental studies approach, presenting twenty classroom-tested cases from dedicated, experienced teachers and researchers in this sub-field. The result is an engaging and versatile volume that presents the core ideas of environmental sociology in concise chapters that are accessible to all students.