حسابداری زیست محیطی و ارزیابی اقتصاد شهری: با توجه به شهرستان پکن به عنوان مورد مطالعه

Urban economy is confronted with increasing biophysical limitations derived from the exhaustion of natural resources and the depletion of environmental capacity, and human cultural diversity has been declining during the fast urbanization. The conventional anthropocentric economics, regarding the natural environment as the ‘exterior’ of human economy, is invalid in the scientific evaluation on the contribution of natural resources and environment as well as human culture when facing the current urban crises. The theory of embodied cosmic exergy, as the latest development of ecological economics and ecological thermodynamics, is introduced in this study to construct an ecological evaluation framework of urban economy. The advantage of embodied cosmic exergy dedicated to ecological economics has been discussed in comparison with other ecological evaluation alternatives. Transformities describing hierarchies and manifesting quality are systematically calculated and tabulated. A new framework of embodied cosmic exergy based on network accounting (EmexNA) is sketched out in this study, taking not only diversity flows but also ecological stocks into consideration. The stock based concept of ‘ecological wealth’ and the flow based concept of ‘ecological cost’ as well as related evaluation indicators are developed based on EmexNA. Taking Beijing city as the case, the network accounting and related ecological evaluation of a practical urban economy are carried out in this study in the light of the basic social, economic and environmental data available from 1990 to 2005 of Beijing. The system construction and the ecological mechanism of the development of Beijing economy are correspondingly illuminated and discussed.

As a typical complex system with multiple hierarchies, urban ecological–economic system can be regarded as consisting of five parts including the natural primary production sector, the natural-economic production sector (i.e. the suburb agricultural production sector), the main urban production sector (including commerce, industry, urban consumers, and so forth), the population production sector, and the culture and information production sector. The industry-based urban production adds to the accumulation of material, energy, information, capital and population fluxes, while accelerates the downfall of natural resources and urban culture. As a heterotrophic and open thermodynamic system originally rooted in the broad natural environment, cities are confronted with increasing biophysical limitations derived from the natural resources depletion and environmental deterioration during their marvelous economic growth [1]. The destruction of cultural diversity becomes increasingly intense in the process of modern industrial revolution based on the huge consumption of fossil fuels.

As a feasible complementation of conventional economic evaluation, the ecological evaluation of urban economy, based on the theory of embodied cosmic exergy, has been constructed. As the latest development of ecological economics and ecological thermodynamics, embodied cosmic exergy has been proven scientific and effective in resources allocation and environmental management, and regarded as effective in ecological accounting and evaluation of urban economy. As the primary and intrinsic power of the biosphere, cosmic exergy has been proven scarce compared with the scale and intensity of human economic activities. Characterized with intrinsic, usable and scarce, cosmic exergy can be regarded as the metric of ecological wealth measurement. Compared with conventional economic evaluation, the embodied cosmic exergy based metric is feasible in avoiding human bias, valid in unified and subjective evaluation of all kinds of ecological wealth (including the conventional free paid resources) and the real cost of human economic activities.