The teaching of ethics in science within the disciplines provides an avenue to deepen students’ scientific understanding and to develop their critical thinking skills. This study showcases a module which connects ethics to science within a large introductory geoscience course. The module components, a tutorial plus homework assignment and an exam question, require students to decide on ethical issues using a 5-step approach that mirrors the scientific decision-making process. The assignment is graded using a developed rubric. An analysis of exam (...) question responses reveals that students correctly identify stakeholders and mention contributions by geoscientists, but have difficulties recognizing their own assumptions. Furthermore, many acknowledge the complexity of the ethical issue at hand. The module provides an example of how disciplinary instructors can include ethics in their teaching and assess students’ ethical decision-making process. (shrink)