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An energy systems view of sustainability: emergy analysis of the San Luis Basin, Colorado
Citation:
CAMPBELL, D. E. AND A. S. GARMESTANI. An energy systems view of sustainability: emergy analysis of the San Luis Basin, Colorado. JOURNAL OF ENVIRONMENTAL MANAGEMENT. Elsevier Science Ltd, New York, NY, 95(1):72-97, (2012).
Impact/Purpose:
To inform the public.
Description:
Energy Systems Theory (EST) is used to provide a context for understanding and interpreting sustainability. We propose that “what is sustainable” for a system at any given level of organization is determined by the cycles of change originating in the next larger system. Furthermore, the pulsing paradigm determines the cycles of change and governs ecosystems rather than succession to a climax state (i.e., a steady state) that is sustainable. Therefore, every decision-maker’s priority should be to know where their system resides in the cycles of change that govern it. This theory was examined by performing an emergy evaluation of the sustainability of the San Luis Basin (SLB) regional system. This region contains a fully developed agricultural system with crop and livestock production, food and animal waste processing components. The SLB serves as a hinterland, in that it exports raw materials and primary products to more developed areas. Emergy indices calculated for the SLB from 1995 to 2005 revealed the relative sustainability of the system, its well-being, and whether it was moving toward or away from more sustainable states: (1) sustainability of the region as indicated by renewable emergy as a percent of total use declined 4%, whereas, the renewable carrying capacity declined 6% over the study period; (2) the total emergy used by the SLB system, a measure of system well-being, was remarkably stable (coefficient of variation = 0.05) over the 11 year period; (3) in 1997 the SLB could support 50.7% of its population at the current standard of living on renewable emergy alone, while under similar conditions the U.S. could support only 4.8% of its population. In contrast to other indices, the Emergy Sustainability Index (ESI), which considers the benefits gained by the larger system and the potential for local environmental damage, increased 34% over the period. The ESI showed the relationship of the SLB with its larger system moved towards sustainability in some years (ESI > 2.0) and moved away from sustainability in others (ESI < 2.0).
