You are here:
Environmental Accounting Using Emergy: Evaluation of Minnesota
Citation:
CAMPBELL, D. E. AND A. Ohrt. Environmental Accounting Using Emergy: Evaluation of Minnesota. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-09/002, 2009.
Impact/Purpose:
This EPA Project Report adds to the information available on the Emergy Analysis of regional systems. It includes further development of the techniques used in an earlier EPA Report on West Virginia. The Minnesota Report may serve to give the larger systems context for studies of regional sustainability within Minnesota. In addition, it provides information needed for the evaluation of important subsystems and industries within the state, e.g., the ethanol industry, mining industries, etc. The initial report on West Virginia was disseminated broadly and it has received considerable attention within the U.S., Europe, and China. The Minnesota Report is expected to receive a similar level of interest.
Description:
Often questions related to environmental policy are difficult to resolve successfully, because robust solutions depend on accurately balancing the needs of both human and natural systems. To accomplish this end the socioeconomic and environmental effects of policies must be expressed in common terms so that both the contributions of the environment and the contributions of the economy to human well-being are valued fairly. Emergy is an accounting quantity that has the property of expressing all forms of energy in terms of their equivalent ability to do work when used in the system of which they are a part. Based on past studies and a previous report in this series, environmental accounting using emergy has proved to be a method that can be used to objectively value the work of the environment, economy and society by using an energy-based unit, the solar emjoule (sej) and a combined emergy-monetary unit the emdollar (Em$). Emergy tabulates the available energy of one kind required for the production of a product or service i.e., the solar joules used up both directly and indirectly in the past to make the product or service. The unit of emergy is the emjoule, which denotes that the energy has been used in the past in contrast to a joule of available energy that is an energy potential that can be used in the present. What something can do when used within its network is represented by its emergy and not its energy. Thus, energy alone is not a sufficient basis for making policy decisions. This USEPA Project Report contains an emergy evaluation of the State of Minnesota and it includes a guide to the Emergy Analysis methods used to characterize a state within the larger context of its region and nation. A summary of the results of this analysis based on the values of emergy indices calculated for the State and their interpretation follows: (1) Twenty-one percent of the emergy used in the State in 1997 was derived from home sources, which indicates a moderate potential for self-sufficiency. (2) The emergy use per person was 1.53E+17 sej/person. This index showed that Minnesotans have a high overall standard of living compared to the national average. (3) The import/export emergy ratio showed 1.33 times as much emergy leaving the State in exports as is received in imports, which indicates a slight imbalance in the exchange of real wealth with the Nation. However, when iron ore (taconite) is removed from the import-export balance, the emergy of exports is only 10% larger than that of the imports. (4) The emergy used per square meter (3.23E+12 sej/m2) indicates that an average location in the State is developed relative to an average place in the Nation. (5) The emergy to dollar ratio was 4.66 E+12 sej/$, thus the purchasing power of a dollar in Minnesota in 1997 was 1.82 times that of an average place in the United States. This ratio had fallen to 1.69 times the national purchasing power of a dollar by 2000. (6) The investment ratio was 3.81:1, which indicates a relatively low intensity of matching between purchased economic emergy invested from outside the State and the emergy of renewable and nonrenewable environmental resources within the State. This index suggests that Minnesota is still an attractive place for further economic investment. (7) The environmental loading ratio was 37.1:1, indicating a more intense matching of purchased inputs with renewable energy from the environment than was found for West Virginia (20.4:1) or the Nation as a whole (19.6:1). Higher environmental loading ratios potentially result in higher stress on ecosystems and a heavier “load” on the waste processing capacity of the environment. (8) Minnesota can support 2.6% of the present population at the 1997 standard of living using its renewable resources alone in their current state of development compared to 3.0% for West Virginia and 4.9% for the Nation.