A combined tool for environmental scientists and decision makers: ternary diagrams and emergy accounting

Ternary diagrams are presented as graphic tools to assist environmental accounting and environmental decision-making based on emergy analysis [Odum HT. Environmental accounting – emergy environmental decision making. John Wiley & Sons; 1996. 370 pp. [1]]. Beyond the unquestionable advantages of graphic interpretation over table analysis, the use of ternary diagrams or phase diagrams, widely used for physical chemistry evaluation of three component systems, permits the use of phase diagram properties to assess the dependence of the system upon renewable and non-renewable inputs, the environmental support for dilution and abatement of process emissions and the system efficiency. The prompt visualization of the emergy accounting data makes possible to compare processes and systems with and without ecosystem services, to evaluate improvements and to follow the system performance over time. With the aim of ternary diagrams, aspects such as the interaction between systems and the interactions between systems and the environment can be readily recognized and evaluated.