Emergy-based Ecological Economic Evaluation of Beijing Urban Ecosystem

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, were 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 explained the level of economic development and environmental pressure of the Beijing economy during 1999 to 2006. Results showed that the development of economy in Beijing was closely correlated with the consumption of the nonrenewable resources and exerting rising load on environment. Of the total emergy use by the economic system, the imported nonrenewable resources from other province contribute most with increasing use from imported nonrenewable resources. Emergy intensity kept rising during the periods, with the increasing of environmental load. The pressure of environmental protect which was caused by over-heated investment in Beijing could be released after finishing the infrastructure construction. The results offer a reference towards the urban metabolic analysis driving economic policy and sustainability.