This draft Recommendation provides environmentally sustainable computing framework and requirements for the ICT sector and enterprise ICT systems in other sectors. Environmentally Sustainable Computing (ESC) not only focuses on ICT infrastructure in data centres and telecommunication rooms, but also considers the entire infrastructure, cloud computing platforms and applications in a coordinated manner to ensure environmental sustainability across the whole service. It helps improve efficiency and reduce GHG emissions in the ICT sector, while further expanding the role of ICT-enable technologies in reducing carbon emission across other sectors globally.