Using module-based courses has been suggested to improve undergraduate science courses. A course based around a series of modules focused on major environmental issues might be an effective way to teach non-science majors about ecology and ecology's role in helping to solve environmental problems. I have used such a module-based environmental science course for non-majors. The course is divided into 5 modules, with each module addressing a key environmental issue, specifically global climate change, human population growth, sustainable use of natural resources, habitat loss, and the value of biodiversity. Each module follows the same basic structure: 1) an introduction to the question, 2) an investigation of the basic science underlying the question, and 3) an investigation and discussion of the human aspect of the question (i.e., what can we do?, what are the costs and benefits of addressing the question?, are there any social, economic, or cultural factors that affect our ability to address the issue?, etc.). Each module has associated laboratory exercises that culminate with field-based student-designed surveys of biodiversity on the Denison University Biological Reserve. The module-nature of the course allows for the integration of science and non-science disciplines around basic environmental questions, and appears to be an effective means of teaching environmental science and ecology to non-majors. (Contains 2 tables.)