We can no longer deny that we are a part of our environment, which we are degrading at an alarming rate. In order to embark on a more sustainable pathway, we need both to conserve and restore ecosystems. This report makes the case for why restoration, in particular, is so important and outlines how the UN Decade can catalyse a movement to restore the world’s ecosystems. Healthy, stable and biodiverse ecosystems are the foundation of our health and well-being, as well as that of our fellow species. However, we have been overexploiting and degrading the world’s ecosystems and wild species, causing the erosion of the very services we depend on (UNEP 2021). This report represents a synthesis of recent research. All selected ecosystems – farmlands; forests; freshwater; grasslands, shrublands and savannahs; mountains; oceans and coasts; peatlands; and urban areas – are being degraded, often at an accelerating rate. Chapter 2 provides a snapshot of the current state of the world’s ecosystems. The need to restore damaged ecosystems has never been greater. Chapter 3 details the myriad ways that nature-based solutions like restoration can benefit the climate, food systems, health and the economy. Much has been done already, and we can build on the lessons learned from existing restoration approaches and initiatives. Chapter 4 provides an overview of different approaches to restoration, guiding principles and helpful technical and scientific innovations, as well as the broader conditions needed to address the drivers of degradation and enable the transition to a more sustainable way of life. The UN Decade on Ecosystem Restoration aims to prevent, halt and reverse the degradation of all kinds of ecosystems, contributing to reductions in global poverty and ensuring that no one is left behind. Running from 2021 until 2030, the UN Decade launches a global movement to restore ecosystems worldwide. Chapter 5 presents the overall strategy for the UN Decade and the way forward.