The idea of land developers submitting an environmental impact assessment (EIA) derives from America's National Environmental Policy Act of 1969. It required developers to make a statement detailing every proposed action that would have a significant impact on the quality of the existing environment. This necessitated a great deal of investigative work. If environmental data is made available to potential developers in the form of GIS it will make the development process more efficient and more environmentally responsible. Planning authorities can use the GIS data to produce strategic environmental assessments (SEA) with regard to possible future developments.
A GIS model is like a subway map. It is diagrammatic. It helps you to find your way about. But it does not tell you where to go. Some people will always choose to stay put; others will want to move forward. They are unlikely to agree on a unitary plan, especially one that has been prepared by old-fashioned technocrats with a commitment to "progress' and "optimal' states of affairs. We all have needs for information: about the environment, about its history, about each other's plans for the future. The strength and power of GIS should be used to make data available in ways that facilitate good decision-making.