Most traditional science works within a very restricted disciplinary domain requiring a careful and often technically rigorous and demanding approach that includes, at least in theory, the use of the Baconian scientific method of test and control in a restricted laboratory environment. This is how most science operates, and it is often a very successful approach. However, such an approach is very difficult to apply to many real problems, including those in the complex natural or seminatural world outside the laboratory where many interacting variables can render laboratory results rather meaningless. For example, cleaning up sewage in a treatment plant can increase air pollution both directly and through the energy required.
One antidote to this problem is systems science, which seeks to find and use general principals, concepts, and equations that are applicable across, and can integrate, many disciplines. Numerous thinkers throughout history have used some kind of systems approach (e.g., Isaac Newton realized that billiard balls and planets both followed the same laws of motion). General systems theory was formalized and popularized by Ludwig von Bertalanffy in a book by that name; he founded the Society for General Systems and advanced its studies. This society is still active, continuing to attract ecologists, physicians, psychologists, engineers, mathematicians, economists, and others who seek new ideas in other disciplines.
There are, generally speaking, two approaches to systems science. The first undertakes analysis of the properties of systems as a whole. For example, one might ask what is the photosynthesis of an entire ecosystem or indeed of the globe as a whole. The most comprehensive, and some might say most controversial, application of this approach is the Gaia hypothesis of deep ecologists James Lovelock and Lynn Margulis. This hypothesis postulates that the earth as a living system itself regulates the chemical and other characteristics of the atmosphere (and other entities) in order to maintain optimal conditions for life. In other words, life maintains its own environment. This concept, or one somewhat like it, has been called self-design by Howard Odum and others, and Odum applies the view especially to ecosystems.
The second general approach is a "systems" analysis of how parts of a system interact and generate the behavior of some entire entity. Such an approach, originally used to link radar, artillery, and aircraft during the Battle of Britain in World War II, has been especially well developed in the engineering sciences. For example, computers are used routinely in designing automobiles to model how springs and shock absorbers interact with wheels and terrain so that automobiles with smoother rides can be designed. Here and elsewhere in a systems approach, the feedback of one motion or operation on the subsequent behavior of the system is of paramount importance. Many systems investigators try to capture the essence of the behavior and other attributes of their ecosystem of interest through the construction of mathematical and/or computer simulation models.
Examples of how systems science has contributed to science include the use of techniques originally designed for measuring photosynthesis and respiration in aquatic ecosystems to understand the metabolism of the Northern Hemisphere. It has also included the application of fisheries analysis techniques to assess the success of drilling for oil. Oil return per unit effort spent in acquiring it, like fishing for fish, decreases with increasing effort.
A systems approach can be applied in many ways, including modeling the fate and transport of pollutants dumped into a river or groundwater. The classic example is the Streeter Phelps model, developed in the 1930s, that predicts the oxygen level in a river as a function of sewage load, dispersion, microbial activity and interactions with the atmosphere. A general systems approach has been most thoroughly developed for the environmental sciences by Odum in General and Systems Ecology. Other specific examples include its use in combined hydrological, biological, and economic models to determine the cheapest way to clean up the Delaware estuary; combined atmospheric and pollutant generation models to predict, for example, acid rain deposition downwind; and models to generate groundwater pollution and its impact. More recently, some efforts to integrate economics into traditional systems analyses of natural systems have evolved. An extensive systems approach has been used, for example, to examine the economy of Costa Rica, not just with the conventional tools of economics but also through a biophysical approach originally developed for natural ecosystems (Hall, 2000). In fact, some kind of systems approach is almost a necessity in any sophisticated environmental impact statement.
Hall, C.A.S., and C.J. Cleveland. (1981). "Petroleum Drilling and Production in the United States: Yield per Effort and Net Energy Analysis." Science 211:576–579.
Hall, C.A.S., ed. (2000). Quantifying Sustainable Development: The Future of Tropical Economies. San Diego: Academic Press.
Odum, Howard T. (1994). Ecological and General Systems. Niwot: University of Colorado Press.
von Bertalanffy, Ludwig. (1968). General Systems Theory. New York: George Brazillier.
Principia Cybernetica Project (PCP) Web site. Available from http://pespmc1.vub.ac.be/DEFAULT .