Abstract
For ecological economic evaluation based on the unified biophysical matrix this research illustrates an updated emergy synthesis in terms of embodied cosmic exergy instead of embodied solar energy, which successes the foundation of systems ecological theory but changes the starting point for the estimation from simply the sun to the cosmos. According to the modified definition implicating explicit scarcity and strict additivity based on the fundamental thermodynamics laws, the updated emergy approach overcomes the confusable and intractable deficiencies of traditional one and shows firmer theoretical basis as well as better applicability. As a case study for the regional socio-economic ecosystem, a cosmic emergy based ecological economic evaluation of the Beijing urban ecosystem during the period 1978-2004 is presented. The local and external resources supporting the concerned ecosystem are accounted and analyzed in a common unit, i.e., cosmic Joule, according to which a series of indicators are applied to reveal its evolutional characteristics through five aspects as emergy structure, emergy intensity, emergy welfare, environmental impacts, and degree of exploitation and economic efficiency. During the analyzed period, the major emergy source sustaining the operation of the ecosystem had changed from the renewable resources exploited locally to the nonrenewable resources purchased from outside. Emergy intensity for the Beijing urban ecosystem kept rising owing to the continuous investment of resources, which not only improved the living standard but also intensified the environmental pressure. Moreover, the increase of exploitation degree was accompanied with the decline of economic efficiency, while the rising emergy investment ratio implicates that Beijing was at the risks of resources shortage and high dependence on external resources
Highlights
Emergy synthesis is one of the unified biophysical matrices for ecological economic evaluation, whose origin can be traced back to Odum’s theory of systems ecology based on the maximum empower principle, the feedback on cybernetics, and the energy transformation hierarchy of the universe [1,2]
The definition of emergy as the embodiment of available energy is theoretically sound in the very beginning, the later induced notion of embodied energy is misleading and would be more appropriately replaced by that of embodied exergy
For a general commodity as a product, a service, or an emission the ecological economic cost can be well measured by the cosmic exergy directly or indirectly consumed in making or sustaining it associated with the concerned time and spatial scales
Summary
Emergy synthesis is one of the unified biophysical matrices for ecological economic evaluation, whose origin can be traced back to Odum’s theory of systems ecology based on the maximum empower principle, the feedback on cybernetics, and the energy transformation hierarchy of the universe [1,2]. As an application of the cosmic emergy approach to the study of urban ecosystem, the Beijing city witnessing significant changes related to its structure, function, and organization is chosen and evaluated in order to reveal its ecological economic vicissitudes during the period 1978-2004. Concluding remarks are drawn in the ending section
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