The task of teaching about acute ecological crisis presents a vital pedagogical challenge and an important provocation for critical scholars. Across various environmental subfields, educators are revisiting fundamental and politically significant questions concerning what to teach, how to teach, and even why to teach as their traditional subject matter transforms around them. In this article, we explore how environmental educators are grappling with the implications of what they are teaching and consider the politicising effects of this predicament. We show how this distinctive educational context, beyond posing bewildering learning challenges, is also creating unique openings for radical scholarship in higher education. Through interviews with educators endeavouring to teach about planetary environmental crisis (from within an exceedingly dire planetary environmental crisis), we examine diverse attempts to interpret the radical demands of this learning challenge and to negotiate its many complexities, practical difficulties, and political possibilities.