/ In the process of devising courses of action to resolve problems arising at the society-environment interface, a variety of planning approaches are followed, whose adoption is influenced by--among other things--the characteristics of environmental problems, the nature of the decision-making context, and the intellectual traditions of the disciplines contributing to the study of these problems. This article provides a systematic analysis of six alternative environmental planning approaches--comprehensive/rational, incremental, adaptive, contingency, advocacy, and participatory/consensual. The relative influence of the abovementioned factors is examined, the occurrence of these approaches in real-world situations is noted, and their environmental soundness and political realism is evaluated. Because of the disparity between plan formulation and implementation and between theoretical form and empirical reality, a synthetic view of environmental planning approaches is taken and approaches in action are identified, which characterize the totality of the planning process from problem definition to plan implementation, as well as approaches in the becoming, which may be on the horizon of environmental planning of tomorrow. The suggested future research directions include case studies to verify and detail the presence of the approaches discussed, developing measures of success of a given approach in a given decision setting, and an intertemporal analysis of environmental planning approaches.Environmental problems have always existed, but the need to study them systematically for determining courses of actions to allocate and/or distribute environmental resources and services among competing uses fairly and efficiently was not felt until the late 1960s and early 1970s. The environmental movement was at its high point, environmental crises were making headlines, leading personalities were drawing the public's attention to the imminent threats of heedless environmental abuse, and the federal government was embarking in ambitious programs to get the mounting environmental degradation under control. Hence, environmental planning emerged as a functional area within the broader field of planning and as an activity undertaken by individuals and organizations dealing with problems arising at the society--environment interface and devising courses of action to solve these problems.The theory and practice of environmental planning exhibit a variety of approaches to the formulation and implementation of solutions to environmental problems. Each approach reflects a particular philosophy and mode of thinking about how these problems can and/or should be defined, analyzed, and solved.