The project aims to initiate, support, and sustain eco-friendly behaviour by means of psychological knowledge. Although research is needed to further propel technological progress, nowadays there is no shortage in eco-friendly options for individuals, institutions, and even countries to pursue (e.g., intelligent energy and water consumption; waste reduction; eco-friendly transportation means, etc.). However, the last ten years have witnessed that the mere availability of “green options” is often not enough; even highly efficient green ideas, technologies, and new programs fail, because individual citizens do not elect to use them. With green options available, perhaps the most critical leverage for a green future is knowledge to spark and catalyse changes on the micro-level. We believe that psychology as a discipline is best equipped to fill this void, because it can draw on long-standing research lines addressing critical steps towards behavioural change, including—but not limited to—the formation of attitudes, social norms, the role of incentives, social dilemmas, successful intervention strategies, self-regulation, or basic needs. The present project is to put this psychological knowledge to practice. Specifically, the project’s main goal is to develop, implement, and evaluate a new teaching module for initiating, supporting, and sustaining eco-friendly behaviour on the level of the individual citizen. By using up-to-date teaching methodologies such as problem oriented learning or service learning, and by borrowing from intervention strategies in psychotherapy, the teaching module does not stop at instructing students. Rather, it aims at qualifying and enabling students to make changes happen, and at initiating positive changes via practical project work.