The ability to think critically is essential if individuals are to live, work, and function effectively in our current and changing society. The activities included in this publication were selected to identify a variety of effective strategies for teaching critical thinking skills through environmental education. Activities include library research and analysis of information; interviewing and analysis of information obtained through interviews, debates, simulations, and role playing; analyzing speeches and presentations; case studies; critical writing for community action; planning alternative actions; and evaluating alternative actions. The activities also emphasize analyses of materials and ideas by individual students, analyses and comparisons of analyses within small groups of students, class analyses and discussions of materials and ideas, comparing student developed materials and statements to published and community statements, and rethinking ideas at all levels of analyses based on new or different information. Topics include recycling, magnetism, packaging, plastics, water use, energy conservation, waste disposal, ecology, plant growth, soil compaction, wildlife, endangered species, carrying capacity, pollution, and zoning. Each activity includes the title, level, subject, reference, objectives, procedures, extensions and variations, and evaluation. Twenty-five references are included. (KR)