As attention to the pervasiveness and severity of environmental challenges grows, technical universities are responding to the need to include environmental topics in engineering curricula and to equip engineering students, without training in ethics, to understand and respond to the complex social and normative demands of these issues. But as compared to other areas of engineering ethics education, environmental ethics has received very little attention. This article aims to address this lack and raises the question: How should we teach environmental (...) ethics to engineering students? We argue that one key aspect such teaching should address is the tendency of engineers towards technical framing of (social) problems. Drawing then on engineering ethics pedagogy we propose that the competencies of moral sensitivity and critical thinking can be developed to help engineering students with problem (re)framing. We conclude with an example from our teaching that operationalizes these competencies. (shrink)