One of us is a physicist. The other is a chemist. For the past four years, we have been teaching a large introductory environmental science course that uses our campus as a lens through which to explore issues relating to sustainability. Our students "ask questions about the energy we use to heat and cool our buildings, the food we eat, the air we breathe, the electricity to run light bulbs and appliances, the goods we purchase, and the waste we create." This course fits in the genre of using "campus as a living laboratory," a term we will discuss later.