Almost twenty years ago, organisations as diverse as the WWF and the World Economic Forum in Davos were promoting digital technology as a solution to the climate crisis. A growing awareness of digital technology’s environmental impact has since tempered that optimism. In this talk, Gauthier Roussilhe, a researcher and consultant specialising in digitisation’s environmental challenges, takes stock of both digital technology’s positive and negative contributions. Trained as a designer, Roussilhe draws not only on scientific studies, but also on concrete expression in design of digital technology’s carbon footprint.