The climate crisis raises questions such as: Why are corporations continuing to produce plastic for their products when more sustainable solutions are available? Does recycling make a difference? Can oil companies be "green" and "sustainable," as their ads claim? Why are factories, landfills, and extraction sites located where they are? Why are known solutions not implemented more quickly, effectively, and broadly? And what can we do that will make a difference? These are difficult questions and require information, complex thinking, and critical analysis to begin to answer them. This article suggests a pathway to grapple with these questions, using sequential lessons that bring sustainability into the English classroom. The lessons are intended to develop students' capacities for positive engagement in climate action by helping them build a knowledge base of the complexity of the issues and then take action. The lessons foreground the literacies of critical thinking, discussion, collaboration, systems thinking, and research-informed argument writing. Primarily, this article aims to help teachers engage students in taking charge of their futures--using their informed voices and taking the first step to becoming climate activists.