In this chapter, we develop the concept of ‘planetary literacies’ and suggest it is useful for thinking through critical literacies for the planet in response to the urgency of children’s concerns about climate change, as expressed in international protests led by Greta Thunberg. We draw on the concept of ‘the Anthropocene’, the proposed new geological age, prompted by human induced changes to the Earth’s biosphere. Drawing on posthuman and new materialist methodologies and the concept of ‘The Anthropocene’ acts as a provocation to more sustainably connect nature and culture, economy and ecology, and the natural and human sciences, in order to address species loss, environmental destruction and global warming. Through an example from teacher education in South Africa, we suggest that our concept of planetary literacies aims to incorporate new political understandings of subjectivity. In this sense, we propose that in pushing the boundaries, critical literacies could significantly include new posthuman, and new materialist approaches, to address the urgency of climate change.