The multiplication of environmental degradations in the end of the 1960's has led to growing criticisms about the industrial development path. It is precisely in this context of conflict between environment and development concerns that the notion of sustainable development has progressively emerged. From that point of view we can reread the history of sustainable development through the framework of negotiation theory, and thus consider this concept as a trial of reconciliation between these two preoccupations - a kind of "win-win" approach between environmental protection and socio-economic development. But if sustainable development can be considered as the result of such an international cooperative approach, it is important then to notice that the following phase of appropriation (by different kinds of stakeholders) seems to be more competitive : states, companies, NGO, local authorities, economists or ecologists nowadays refer to the notion of "sustainable development"... without referring to the same definition of the notion. Debates about "weak" and "strong" sustainability give us a good illustration of that "fight for appropriation". This competitive context is fundamental to understand the question of sustainable development evaluation methods and indicators : such normative tools indeed offer a strong capacity of appropriation, as they oblige to make "rigid" a concept often considered as "soft". These tools thus appear as deeply embedded in a debate that is, in the same time, both technical and ideological (Chapter 1). At the local level, in the specific field of urbanism and urban planning, it is interesting to notice that the notion of sustainable city, as well as the one of sustainable development, has progressively emerged after the rise of criticisms (led by the urban ecology movement) of the modern city model (Athens Charter). Sustainable city (Aalborg Charter) can thus be seen as a trial of reconciliation between both the modern city and the ecological city models (Chapter 2). Due to their capacity of making the concept rigid, evaluation methods and tools elaborated at the local level in cities in France and Switzerland permit us to better understand what local authorities precisely mean by sustainable development. The study of these tools thus makes it possible for us to confirm the tendency of local authorities to use sustainable development as a way to conciliate diverging interests at the local level. The question of future generations and other territories' interests seems to be more difficult to tackle (Chapter 3). Studying the contexts in which these tools have been used and designed leads us to the following conclusion : sustainable development seems to be often considered as a technical matter, delegated from the people's representatives (the elected) to the local authorities' operational and technical staff ; these latter then has to tend to make "as sustainable as possible" political decisions, afterwards. Such evaluation tools thus fail to make sustainable development matters a leading guideline in the political decision making process (Chapter 4). Our case study, the Greater Lyon, in France, permits us to validate several of the hypothesis and conclusions above mentioned (Chapter 5). In the end, the difficulty of tackling sustainable development matters at the local political and administrative levels obliges us to question the ability of representative democratic systems to tackle these new concerns. In particular, sustainability obliges us to broaden the concept of public interest, both in time and spatial dimensions. By introducing the interests of non-represented people (future generations and other territories' inhabitants) in the usual representative system, sustainability seems to question the fundamental basis of modern democracies.
