Emergy analysis for tourism systems: Principles and a case study for Macao

To support a sustainable combined ecological and economic system, the flows and quantities of emergy must be in balance; that is, a net surplus of emergy must flow into the system to account for the fact that socioeconomic systems are rarely self-sustaining. When this flow is not available, the system will degrade. Although emergy synthesis is a better method for measuring the sustainability of an economic system than simplistic quantification of monetary flows, it is difficult to evaluate specific systems such as tourism due to a lack of sufficient data and the lack of a powerful accounting method for materials and energy flows. Thus, published articles often unclearly or incorrectly use emergy accounting for ecotourism. To permit this use, it is important to understand the advantages and drawbacks of the various emergy accounting approaches so that the correct technique can be used to assess the sustainability of tourism at local or national levels. In this paper, we examined the following emergy issues: comparing the four main emergy accounting approaches available for studying tourism flows, distinguishing the consumption of emergy by tourists from the equivalent emergy their expenditures could purchase, and showing how these approaches work using a case study of tourism in Macao from 1983 to 2007.