It is estimated that each year the world’s population consumes more renewable resources than the planet can generate. This trend is increasing as the world’s middle classes grow and extreme poverty decreases. In this context, the circular economy is attracting growing interest from citizens, entrepreneurs, governments and academia. To avoid resource depletion, this “tomorrow’s economy” proposes the reduction of waste. It is based on extending the useful life of products, intensifying recycling – or even ending waste -, sustainable management of resources, production policies, and the shared use of goods and services. Finally, it is resolutely dissociating itself from unlimited growth in resource consumption. This book, written under the auspices of the Institut de l’environnement, du développement durable et de l’économie circulaire (IEDDEC), presents the reflections of some fifty experts, notably in the fields of environment, industrial or chemical engineering, management, but also in economics, geography, anthropology and philosophy. Using accessible language, it addresses the need to move towards a model that respects planetary boundaries and contributes to the well-being of individuals and communities. This book is part of an open access pilot project carried out in collaboration with the UdeM Library Department. The digital versions (in French) can be downloaded free of charge.