Chapter 1 – How do we change the world? – presents the rationale of the book, its aim, and scope, introduces key concepts and outlines the state of research on and for transformations toward sustainability. The chapter highlights different calls for sustainability transformations in the United Nations 2030 Agenda, countries’ contributions to the Paris Agreement and subsequent negotiations within the United Nations Framework Convention on Climate Change. The chapter further discusses the difference between the concepts of transformation and transition. The chapter argues that greater conceptual clarity on sustainability transformations across societies in the world facilitates decision-making and planning in form of democratization, organizational effectiveness and international cooperation.