Systems account of societal exergy utilization: China 2003

As a possible contribution to the exergy-based approach in systems ecology, the account of the exergy utilization in a society is considered a basic vision of the third stage of the universal hierarchy of exergy as the fundamental natural resource, on the national or regional scale just next to the first two stages on the global and terrestrial scales, and thus may provide a basis for the ecological systems analysis diagnosis of the socioeconomics. In the light of the scarcity and usefulness of exergy and in part as development of the exergy account scheme initiated by Milia and Sciubba and illustrated by Ertesvåg, the concept, diagram and implications of the systems account of societal exergy utilization are presented and illustrated, as a complement to the cross-sectional account scheme initiated by Wall. A systems account of societal exergy utilization is carried out for China 2003. The society system, supported by domestic natural resources and import from and export to other countries or regions, is diagrammed with seven independent and complimentary sub-systems of extraction sector, agriculture sector, conversion sector, industry sector, tertiary sector, transportation sector, and domestic sector. The exchange and utilization of resources and products was quantified in terms of exergy between the sectors of the society and between the sectors and the natural environment or other countries or regions. The total societal exergy use amounts to 66,525 PJ, of which 25.1% is used in the industry sector, 24.6% in the domestic and households, 21.4% in conversion, 10.4% in agriculture, 7.8% in tertiary, 6.2% in extraction and 4.5% in transport. The ecological efficiency defined for the production sectors as the exergy outflow divided by the inflow is estimated as 92.9% for the extraction sector, 44.6% for the agriculture sector, 30.0% for the conversion sector, 27.7% for the industrial sector, 18.0 for the transportation sector, 41.9% for the tertiary sectors, respectively. Net input of resource exergy to the Chinese society amounted to 66.17 EJ, which is 50.90 GJ per capita, 5.64 MJ per GDP Yuan, or 2.99 MJ per M2 Yuan.