An exploration of reliable methods of estimating emergy requirements at the regional scale: Traditional emergy analysis, regional thermodynamic input–output analysis, or the conservation rule-implicit method

In this paper, several alternative methods of computing cumulative emergy requirements at the regional scale are constructed, with their advantages and disadvantages addressed. The traditional emergy synthesis originating from the H.T. Odum's contribution appears suboptimal from the theoretical as well as methodological viewpoints. It fails to account for the intra- and interregional shipments of products, and necessarily underestimates the life-cycle assessment of emergy requirements. On the contrary, the Ghosh thermodynamic input–output frameworks provide a promising method for estimating emergy requirements. Of the two Ghosh modeling schemes, the interregional input–output model offers a superior medium to the single-region model. Furthermore, the Ghoshian regional input–output framework can be extended to incorporate the conservation conditions. It appears that the conservation rule-implicit interregional input–output framework can also be a reliable method for emergy estimation. Overall, the Ghosh interregional input–output framework, regardless of thermodynamic or conservation rule-based, provides a most favorable technique. This conclusion confirms the prevailing criticisms of the traditional emergy synthesis in the related literature.

► Methods of estimating emergy consumption on the regional scale are established. ► The interregional I–O scheme is advantageous in estimating emergy requirements. ► The conservation rule-implicit interregional scheme also offers a reliable outlet.