Emergy measures of carrying capacity to evaluate economic investments

This paper outlines a method for determining carrying capacity for economic investments based on an emergy evaluation of the environmental resources of a region. Using data from tourism development in Mexico and Papua New Guinea, the concept of carrying capacity is related to intensity of development, environmental support area, and the "fit" of economic development in local environments and economies. Emergy, a unit of resource use and work potential, is used to quantitatively evaluate intensity of development. Emergy evaluation is briefly described and the evaluations of tourism used to further explain the methodology. The total annual resource use for the tourist resorts and the economies in which they are embedded (including inputs of renewable and nonrenewable resources and purchased goods and services) was calculated and converted to emergy units. The renewable resource base and an Environmental Loading Ratio (ELR), are proposed as a means for determining both long term and shortterm carrying capacity respectively. The concept of sustainable development is related to the net emergy benefits that result from development. Expressed as a ratio of the amount of emergy received by the local economy to the amount that is exported (embodied in tourists), sustainability is suggested to result from a positive emergy trade balance.