This paper gives some examples of the application of systems analysis (the examination of the elements and linkages in an interacting group of items forming a unified whole) to the issue of human development and environmental change. The various examples, taken from a report submitted to the United Nations Conference on Environment and Development (UNCED), deal with four basic human needs (food, water, energy and waste assimilation) and illustrate that: (1) it is possible to formulate holistic conceptual models of the socio-ecological system in which we live; (2) systems analysis can help us understand the constraints we face in terms of population growth, natural resources, and the assimilative capacity of the environment for wastes; [...]