Emergetic ternary diagrams: five examples for application in environmental accounting for decision-making

Abstract

In a recent paper, “A combined tool for environmental scientists and decision makers: ternary diagrams and emergy accounting.” [Giannetti BF, Barrella FA, Almeida CMVB. A combined tool for environmental scientists and decision makers: ternary diagrams and emergy accounting. J Clean Prod, in press] Ternary diagrams were proposed as a graphical tool to assist emergy analysis. The graphical representation of the emergy accounting data makes it possible to compare processes and systems with and without ecosystem services, to evaluate improvements and to follow the system performance over time. The graphic tool is versatile and adaptable to represent products, processes, systems, countries, and different periods of time. The use and the versatility of ternary diagrams for assisting in performing emergy analyses are illustrated by means of five examples taken from the literature, which are presented and discussed. It is shown that emergetic ternary diagram's properties assist the assessment of the system efficiency, its dependence upon renewable and non-renewable inputs and the environmental support for dilution and abatement of process emissions. With the aid of ternary diagrams, details such as the interaction between systems and between systems and the environment are recognized and evaluated. Such a tool for graphical analysis allows a transparent presentation of the results and can serve as an interface between emergy scientists and decision makers, provided the meaning of each line in the diagram is carefully explained and understood.