Changes in Planning Theory and Methods related to New Principles and Goals of Environmental Sustainability

Environmental sustainability means to maintain over time “the set of relationships between human activities, with their rapid dynamics, and biosphere, with its usually slower dynamics” (Tiezzi, 1995, p.73). Environmental sustainability is the specific goal of environmental policies. Nevertheless, it is widely recognised that the domain of environmental policies and that of spatial policies largely overlap (UNCED, 1993; CEC, 1990; EGUE, 1996; OECD, 1992 and 1996). The city represents the context in which the ecological, social and economic implications of current environmental policies are most manifest. This prompts the need for urban planning to widen its field of action in order to include such problems as ecological flows management and the ecological balance of human activities (White, 1994; Wackernagel and Rees, 1996). Nevertheless, to regard the contribution of urban planning to environmental sustainability as something limited to the above-mentioned issues seems too reductive. Spatial planning is aimed at drawing up a programme of physical and social changes for a given territory. If it really wants to contribute effectively to environmental sustainability, it needs to focus on the spatially defined relationships between man and nature. That means that planners must not only widen their theoretical background and tools; they must also change them. The paper will present the main results of the research we conducted over the last few years, with the aim of identifying the changes in planning theory and methods required by environmental sustainability.