Book excerpt: The current loss or degradation of biodiversity due to human impact is now occurring at an unprecedented pace at local and global levels, threatening our environment, economies, cultures and societies. This pedagogical kit presents our current knowledge of the various hierarchical levels of biodiversity and the role it plays in the maintenance of human cultures, identities and well-being. It also illustrates plausible scenarios for biodiversity in the years to come and the kind of concrete actions that can be put in place to ensure sustainable development.