This document summarizes the work and vision of the UNESCO Chair on Reorienting Teacher Education to Address Sustainability at York University in Toronto, Canada. The Chair was initially created in 1998 to engage 60 million teachers in education for sustainable development and produce guidelines and recommendations. Over three phases from 2000-2015, the Chair developed ESD guidelines, implemented them at over 250 institutions worldwide, and now partners on the new Global Action Program. Current activities include research, advising governments, and launching new ESD institutes. The Chair aims to further scale up ESD efforts and help higher education commit to sustainable development.