Scientists have increasingly focused attention on far-reaching environmental threats, such as climate change, ozone depletion, and deforestation, that transcend national boundaries. A new concept, global environmental problems, has entered the public arena, particularly in the area of foreign policy and economic matters. This unit explores the relationship between public policy in the United States and the ecological health of the planet. Students join in the process of assessing global environmental problems, grappling with tough questions that are confronting U.S. policymakers. The unit's framework is four distinct options that allow students to consider a range of alternatives for U.S. policy toward global environmental problems. Exploring a wide-ranging spectrum, students can gain an understanding of the values underlying specific policy recommendations. The Teacher Resource Book contains a day-by-day lesson plan and student activities. The lesson plan begins by introducing students to the concept of global environmental problems. The second day of the lesson plan engages students in a role play that delineates the contrasting perspectives of different regions of the world toward environmental issues. An optional science lesson examines humanity's impact on the global carbon cycle. After studying the scientific causes and international ramifications of global environmental problems, students evaluate U.S. options in the course of a 2-day simulation. They conclude by applying what they have learned to developing their own recommendations for U.S. policy. Teachers may also find the "Alternative Three-Day Lesson Plan" useful. The student text invites students to weigh the significance of global environmental problems in the formulation of U.S. foreign policy. The unit traces the entry of global warming, ozone depletion, population pressures, and other worldwide environmental threats into the sphere of public policy. Students weigh the choices and trade-offs involved in protecting the environment. The first section of the background reading has been designed to introduce students to the most significant global environmental problems, while Parts 2 and 3 explore the economic and political dimensions of the environmental challenges facing the planet. Lists 16 supplementary resources, including Web site addresses. (BT)