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Emergy and Its Importance
Citation:
CAMPBELL, D. E. Emergy and Its Importance. EPA/600/S-08/003, 2008.
Impact/Purpose:
This Environmental Research Brief is intended to explain the environmental accounting concept of emergy in layman’s terms and to communicate its general importance to the public. It will be used initially on a mixed audience at a symposium to be held in Duluth in April 2008, which has the goal of developing a research plan for a sustainable northern Minnesota. If successful the impact of this brief may be large; however, if does not strike a chord in the mind of the average person it could be a failure. Success will mean that it communicates this complex idea in simple terms so that a person with a high school education can understand its meaning and grasp it potential importance. If the brief communicates in this way, it will set the stage for general consideration of this concept in public discussions of environmental policy.
Description:
Emergy is an important quantity needed for public policy analysis that is based on a complex methodology. The intent of this Environmental Research Brief is to define emergy and its importance in a manner that is accessible to everyone with at least a high school education. Emergy is all the available energy of one kind used-up both directly and indirectly in the past to make a product or service that exists in the present. Emergy is expressed in its own unit, the emjoule, which connotes the energy (joules) used in the past, as compared with joules of energy available in the present in products and services. For most evaluations of environmental systems, we use solar joules as the base unit. Emergy can be thought of as a kind of energy memory that is carried forward in the capacity of each individual thing to do work, when it is used for its intended purpose within a system. It is important because maximizing emergy flows is hypothesized to be the criterion that determines success in evolutionary competition. Therefore, we must understand and use nature’s value system (emergy), if we hope to assess the environment fairly for accounting purposes and discover the information that we need to make wise public policy decisions.