Monitoring trends of urban development and environmental impact of Beijing, 1999-2006.

The high rates of environmental change and accelerated species loss in the urban development process should be quantified to rebalance the social and environmental dimensions of sustainability. In this study, an emergy-based environmental impact assessment model is designed according to the framework of the Eco-Indicator 99 for monitoring the negative effects on human well-being and ecosystem integrity in the urban development system of Beijing from 1999 to 2006. The environmental impact assessment model is based on the sustainability promotion perspective, and emphasizes the determinants of human health and ecosystem integrity in the urban development process. It is vital that the links among human health, ecosystem integrity and urban sustainability are therefore considered especially from the perspective of a supply-side environmental cost evaluation (including ecological service supply, ecological and economic losses and investment for treatment). Results suggest that: (1) out of all the pollutants, ecological services were mainly used to dilute sulfur dioxide and NH(3)-N; (2) nitrogen dioxide and greenhouse gases released by the urban system contribute heavily to both ecological and economic losses evaluated in emergy terms; and (3) emissions impact, mainly from airborne pollutants, with small contribution from waterborne emissions, generally increases from 1999 to 2006, undermining the sustainability of Beijing. The emergy synthesis proves to be very appropriate to account for large-scale and indirect costs generated by pollution as side effects of economic activity. Such knowledge is a necessary pre-requisite to perform a reliable cost-benefit evaluation of urban sustainability strategies, and provide guidance for policy decision making to maximize benefits and minimize negative impacts.