In recent years we have seen increasing youth activism on climate and other sustainability issues. This paper presents a theoretical framework for further research on young sustainability activists as public educators. The point of departure is taken in Latour's argumentation concerning the need to create new attachments to the Earth. In line with this, we highlight the importance of aesthetics and experiences conceived as integrated sense-perceptional, emotional and intellectual faculties. The second part of the paper moves into social movement theory, to explore what role the Youth for Sustainability movement may have in creating new attachments to the Earth. Drawing on Melucci, emphasis is put on the movement's collective identity making. Furthermore, following Ranciere, the ability to interrupt the distribution of the senses is stressed. Examples of youth activism for sustainability are presented and interpreted, which points to the potential of children and young people to act successfully. The last part of the paper moves into pedagogical theories to explore how this kind of youth activism fostering new attachments to the Earth can be conceived as public pedagogy. We thereby refer to Biesta's distinction between pedagogy for the public, pedagogy of the public and pedagogy for publicness.