"People and Environmental Changes" is one of the "Preparing for Tomorrow's World" (PTW) program modules. PTW is an interdisciplinary, future-oriented program which incorporates information from the sciences and social sciences and addresses societal concerns which interface science/technology/society. The program promotes responsible citizenry with increased abilities in critical thinking, problem-solving, social/ethical reasoning, and decision-making. This teaching guide discusses the purposes of the module (which includes an examination of issues that arise as a result of human activities in the physical environment), general strategies employed (focusing on the dilemma debate/discussion technique), module structure and objectives, and use of dilemmas in the school curriculum. Instructional strategies are provided for the readings, activities, dilemmas, and discussions presented in the two-section student manual (section 1 focusing on planned environmental changes and section 2 focusing on unplanned environmental changes). A chart indicating moral issues (as defined by Kohlberg) contained in the dilemmas presented in the student materials, suggested schedule of activities, and bibliography on environmental modification are also provided. The module may be used as a separate unit of study, as a mini-course, or incorporated into such existing subject areas as social studies, language arts, or science. (JN)