This study problematizes what is meant when one talks about classroom activities concerning environmental and sustainability issues as being authentic or not. It reports excerpts from three classroom discussions which start from questions formulated by the students themselves concerning issues related to sustainable development. It examines how the different questions give rise to altered kinds of participation and shows that the students' involvement shifted between either a distanced factual level of communication, or a personal level of communication. The result indicated that the nature of authenticity in a discourse differs depending on which question initiates it. If the initiating questions allow the students to distance themselves from the subject matter, then one type of authenticity is created. If, on the other hand, the questions give the students an opportunity to establish value-relations, or to dare to take a personal standpoint, as political subjects, to the issues at hand then the personal authenticity becomes another.