This “clicker case” begins by assessing students’ impressions of global climate change and the role that human activities play in recent global warming trends. Students assume the role of an intern working for a U.S. senator. They need to understand the scientific evidence for human impact on climate change so that they can advise the senator on future policy decisions. The case was designed for use in a one-semester introductory biology course taken primarily by freshmen and sophomores to fulfill a general education requirement, but could be used in any introductory biology course or in an ecology or environmental science course. It consists of a PowerPoint presentation (~1.6MB) presented in class that is punctuated by multiple-choice questions students respond to using personal response systems (“clickers”). The case can be adapted for use without these technologies.