Abstract
Emphasizing global environmental issues in classes presents students with powerful, comparative perspectives on controversial issues. Yet, students cannot make critical judgments without first understanding the structure of critical reasoning. The logic of argument forms used to make critical judgments is a necessary tool that may be conveyed through an interactive classroom activity, drawing on discipline-specific examples that reinforce the content of a course. Two argument forms—convergent reasoning and inference to the best explanation-are described, with instructions for an interactive activity. Examples are drawn from issues of industrial ecology and the human dimensions of global change.