Emergy-based Ecological Economic Evaluation of Beijing Urban Ecosystem

摘要

This emergy-based urban economic account provided a historical portrait of the urban economy and its structures to understand the overload of the biosphere's assimilative capacity. The basic situation of the urban economy, involving the indigenous resources base, emergy consumption patterns, emergy exports and imports, was investigated, accounted and discussed. Using a series of ratios and indices arising from emergy analysis, including emergy intensity, environmental load ratio and environmental sustainability, this paper analyzed the economic development in Beijing during the years of 1999 to 2006 and the heavy pressure it has put on the environment. Results showed that the development of economy in Beijing was closely correlated with the consumption of the non-renewable resources and it was exerting rising loads on the environment. Of the total emergy use by the economic system, the imported non-renewable resources from other provinces contributed most with increasing use from imported nonrenewable resources. Emergy intensity kept rising during the periods, with the increase of the environmental loads. The pressure of environmental protection, which was caused by the over-heated investments in Beijing, could be released after the completion of the infrastructure construction. On the whole, the results of this paper outlined a frame of reference towards how the urban metabolic analysis could drive the economic policies and sustainability.