By the mid 1980s, the methods developed through Energy Analysis had reached an important transition. Procedures had been developed for quantifying renewable and nonrenewable energies, energy quality was being related to successive transformations, and global solar energy was increasingly being used as a common basis for comparing different inputs. What remained unsettled was both the terminology and the larger accounting framework into which these methods would develop.
The term embodied energy had been used for the energy required through successive transformations to produce a resource or product, but it was easily confused with conventional meanings of energy contained in materials or consumed during production. During the mid 1980s, David Scienceman joined discussions with H.T. Odum and M.T. Brown at the University of Florida that produced a more distinctive terminology. Emergy, spelled with an m, distinguished the available energy previously required to produce a resource, product, or service from the energy actually contained in it. Transformity, a term attributed by Scienceman to H.T. Odum, replaced the earlier terminology of energy quality factors and energy transformation ratios and expressed emergy per unit of available energy produced. Empower provided a corresponding measure of emergy flow per unit time.
The new terminology did not represent the sudden invention of a new method. It provided clearer names for concepts and calculations that had developed through earlier work on energy quality, Fossil Fuel Work Equivalents, embodied energy, global solar equivalents, and energy transformation ratios. By 1987 the new terminology was being applied explicitly in comparative national accounting in Emergy of 13 Nations. What increasingly changed during the late 1980s and 1990s was the organization of these concepts into a systematic method for evaluating the environmental and economic inputs supporting systems.
An important theoretical step followed in 1988 with Odum’s Self-Organization, Transformity, and Information. Transformity was no longer simply a means of converting energies to a common basis; it was interpreted as a quantitative measure of position within an energy hierarchy. Higher-transformity processes operated at progressively higher levels of the hierarchy, where smaller energy flows could exert feedback and control over larger flows at lower levels. Odum connected transformity with self-organization, information, spatial scale, and turnover time. He also used emergy to reformulate the earlier Maximum Power Principle as a principle of self-organization for maximum emergy use. Emergy and transformity were thus becoming integral parts of the broader systems theory rather than simply tools of environmental accounting.
An important setting for this development was a long collaboration with the Cousteau Society beginning in the mid 1980s. At a time when conventional research support for emergy was limited, the Cousteau projects provided opportunities to evaluate large environmental systems and resource controversies in different parts of the world. Studies included the Amazon and the Jari development, Papua New Guinea, the Mississippi River, the Sea of Cortez and Nayarit coast of Mexico, Thailand and hydroelectric dams on the Mekong River, and the Exxon Valdez oil spill in Alaska. Although each project addressed problems particular to its location, together they provided opportunities to examine broader questions involving trade, environmental degradation, resource use, economic development, and the movement of resources among regions and nations.
As with the major research programs of the preceding decades, these studies did more than apply an already completed methodology. Emergy accounting was tested against systems operating at very different spatial scales and under very different environmental and economic conditions. The work required decisions about system boundaries, renewable and nonrenewable inputs, imported resources and services, exports, trade, and the relationship between environmental contributions and monetary exchange. Applications to watersheds further explored relationships among spatial hierarchy, geopotential energy, water, and transformity.
Emergy analysis also increasingly moved into national and international accounting. Studies of Taiwan, Ecuador, Italy, China, Sweden, Korea, Hong Kong, and other systems examined environmental resources and economic activity within the same accounting framework. Renewable environmental inputs that had little or no monetary value could be evaluated together with fuels, materials, goods, and services exchanged through the economy. Emergy therefore provided a means of making visible contributions from the environment that were largely absent from conventional economic accounts.
The scope of the method also expanded beyond resource accounting. During the late 1980s and 1990s, emergy concepts were applied to information, biological diversity, universities, watersheds, agriculture, forests, and questions of environmental value. These applications were closely connected to continuing theoretical work on hierarchy, self-organization, maximum power, pulsing, and transformity. Emergy was therefore developing within the larger framework of Systems Ecology rather than as an independent accounting procedure.
This period was also one of consolidation and theoretical refinement. Large research contracts became less dominant, while the Systems Seminars at the University of Florida increasingly provided a setting for extended discussions of theory and the philosophy of science. Ideas concerning self-organization, maximum power, pulsing, hierarchy, and transformity continued to be examined and refined. At the same time, advances in personal computers allowed systems models to be developed and explored more readily, eventually including graphical blocks based on the Energy Systems symbols that could be connected to construct and simulate models.
Increasing attention was also directed toward environmental decision making and public policy. The establishment of the Center for Environmental Policy at the University of Florida provided a more appropriate institutional setting for work that increasingly extended beyond wetlands and ecosystem research to questions of environmental value, economic development, resource use, and policy. Odum frequently described emergy analysis as a form of quantitative environmental policy: a way of using systems analysis and environmental accounting to compare alternatives while recognizing contributions from both the environment and the economy.
By the early 1990s, the emerging framework was being applied explicitly to public policy. Work addressed such diverse problems as shrimp aquaculture in Ecuador, development alternatives in Papua New Guinea, environmental and economic interactions in Taiwan and Italy, forest production in Sweden, natural capital, biodiversity, and national resource use. These studies increasingly demonstrated that environmental and economic systems could be evaluated within the same accounting framework without assigning monetary prices to environmental processes simply because they contributed to economic production.
The development culminated in 1996 with the publication of H.T. Odum’s Environmental Accounting: EMERGY and Environmental Decision Making. The book brought together the concepts, definitions, accounting procedures, and applications that had developed during the preceding decades and presented them as an integrated framework for evaluating environmental and economic systems. Emergy provided the common accounting basis, transformity related products and processes to the emergy required to produce them, and the systems framework established the boundaries, pathways, interactions, and hierarchy within which those quantities acquired meaning.
The publication of Environmental Accounting did not mark the completion of emergy theory, but it did mark an important transition. What had begun with attempts to understand differences in energy quality had developed into a systematic method for accounting for the available energy previously used, directly and indirectly, to produce resources, products, services, and economies. The publication of Environment and Society in Florida in 1998 extended many of these ideas into education, bringing systems thinking, environmental accounting, and the relationships between environment and society together for a broader audience.
Milestones and Key References
1986–1987 — Emergy and transformity acquire a distinct vocabulary
Discussions involving David Scienceman, H.T. Odum, and M.T. Brown produced terminology that distinguished the developing methodology from conventional energy analysis and from the ambiguous language of embodied energy. Scienceman’s 1987 Energy and Emergy set out and discussed the new terminology, including transformity, a term he explicitly attributed to H.T. Odum, and emergy, which distinguished the energy previously required to produce something from the available energy contained in it.
Energy and Emergy — David Scienceman (1987)
1984–1990s — Cousteau Society projects as a laboratory for emergy
A continuing series of international projects allowed emergy methods to be developed and tested on large environmental and economic systems, including the Amazon, Papua New Guinea, Mississippi River basin, Mexico, Southeast Asia, and Alaska.
Energy Systems Overview of the Amazon Basin – Odum, et al. (1986)
Energy Systems Overview of the Mississippi River Basin – Odum et al, (1987)
Emergy Analysis and Policy Perspectives for the Sea of Cortez, Mexico – Brown et al. (1991)
EMergy Analysis Perspectives of Thailand and Mekong River Dam Proposals – Brown and McClanhan (1996)
1987 — National accounting recast in emergy terms
Emergy of 13 Nations reformulated the earlier IIASA national Energy Analysis using the newly developed emergy terminology. The underlying accounting framework remained substantially the same, but “emergy” replaced the earlier language of embodied energy, marking the transition from Energy Analysis to what would become environmental emergy accounting.
Emergy Analysis Overview of Thirteen Nations. H.T. Odum and E.C. Odum (1987)
1988 — Emergy and transformity integrated with systems theory
In Self-Organization, Transformity, and Information, Odum related transformity to energy hierarchy, feedback, information, spatial scale, and self-organization. He also reformulated the earlier Maximum Power Principle in terms of maximizing emergy use, integrating the developing emergy methodology with his broader theory of system organization.
Self-Organization, Transformity, and Information — H.T. Odum (1988)
Early 1990s — Emergy becomes a tool for environmental policy
Applications increasingly addressed wetlands, natural capital, biodiversity, development alternatives, resource use, nations, and environmental-economic decision making. Odum’s work during this period increasingly treated emergy as a quantitative basis for environmental policy. The archive documents this expansion through papers on wetlands, natural capital, ecological economics, forests, and other applications
Ecology and Economy: Emergy Synthesis and Public Policy in Taiwan – S-L. Huang and H.T Odum, (1991)
1996 — Environmental Accounting
Environmental Accounting: Emergy and Environmental Decision Making consolidated the concepts, terminology, accounting rules, indices, and applications developed over the preceding decades into a comprehensive methodology.
Environmental Accounting: Emergy and Environmental Decision Making – H.T. Odum (1996)