There is a growing public and scholarly attention to the environmental footprint of digital technologies, and to the climate responsibility of technology corporations and social media platforms specifically. Developing a critical understanding of the environmental responsibility and accountability of digital platforms, Platforms and the Planet focuses on the environmental responsibility of the so-called Big Tech, their digital media platforms and their role in the sustainability transition as a discursive, material, and ethical question.Written from a much-needed critical and cross-disciplinary perspective, challenging the prevailing perspective on digital platforms as "green" and non-material entities, the chapters unpack their non-sustainable, material essence. Bridging critical platform studies with environmental studies and environmental communication studies, the chapters explore three broad themes. First, the chapters unpack what environmental sustainability means in relation to platforms. The second theme scrutinises the material and infrastructural dimensions of the digital platform society from the perspective of sustainability and global justice. Third, the chapters dive into the discourses of accountability by both digital platforms and actors criticizing them.This edited collection is compelling reading for a wide range of researchers and students both in the fields of media and communication studies, digital sociology, and other fields of critical technology studies and environmental studies. The book will also be useful for those interested in global platform companies from the perspective of management and organization studies or more broadly as societal actors.