In 2015, the United Nations (UN) General Assembly adopted a resolution titled "Transforming our world: the 2030 Agenda for Sustainable Development" and a set of 17 Sustainable Development Goals (SDGs). The notion of "transformative education" is being mainstreamed in the work of UNESCO within the new framework of the SDGs, which officially succeeded the Millennium Development Goals (MDGs) and Education for All (EFA). This article briefly outlines the shifting international discourses surrounding Education for Sustainable Development (ESD), now enshrined in SDG Target 4.7. The meanings of ESD have shifted in relation to other education movements, including Environmental Education, EFA, and more recently, Global Citizenship Education (GCED). By reviewing how ESD and GCED--as currently defined and promoted by UNESCO--approach climate change and the question of securing a sustainable future for humanity, the article delineates how the recent marriage of ESD and GCED in one target of the SDGs is weakening, rather than reinforcing, their transformative potentials. It concludes by pointing out the limitations of global policy initiatives for education and proposing ways forward to ensure that education contributes to shaping a more sustainable world.