Emergy signature for human services in Portuguese traded resources

Abstract

The main objective of this paper is to present the Emergy Synthesis Methodology, as a different approach, to measure and evaluate the significance of human services flows (imported and exported) in Portuguese Economic System, in the years from 2000 to 2009, and comparing it with the magnitude of traded flows of energy and materials. Emergy (from embodied energy) is a concept from ecological engineering and economy and is a special measure of the previous work done to make something (a good or a service), whether the work was done by natural processes or by humans. All the main flows, either, goods or services, that cross the boundaries of a system are accounted and are converted to a single metric, the emergy measure in solar equivalent joules, seJ. To evaluate the emergy assigned to different kind of resource flows that support the Portuguese economic activities, the Emergy Synthesis Methodology of states and nations, presented in several studies was considered. Attention is given to emergy assigned to flows of imported resources and of exported resources. Concerning the emergy of human services in imported resources, which include imported services (including tourism) and services in imported goods, results show that they have the lowest contribution to the total imported emergy flow, accounting for 17.6% in 2000 and 17.0% in 2009. On contrary, as far as exported emergy flows are concerned, the largest contribution was from services, which includes exported services (including tourism) and services in exported goods, accounting for 67.6% and 60.8% of the total exported emergy flow, respectively in 2000 and 2009. Results show that, in the period, the amount of emergy exported in flows of human services was approximately 3.4 to 4.9 times greater than the amount that it was imported. As emergy measure the amount of resources required to drive a process and make products, it is a “donor side value” and hence, from emergy perspective, Portugal presented a deficit in human services trade. This means that more Portuguese resources, associated to human services, were delivered to the exterior than those that were received from outside.