By the late 1990s, emergy and Systems Ecology were no longer developing primarily within a single research group at the University of Florida. Researchers in many countries were applying, testing, and extending the methods, and an increasingly international research community was taking shape. Conferences, visiting scholars, collaborative projects, and new research centers provided settings in which ideas could circulate and develop beyond Gainesville.
Two alternating conference series became particularly important. Advances in Energy Studies, organized in Italy, brought together researchers approaching energy and environmental systems from different theoretical traditions. In alternate years, the Emergy Synthesis: Theory and Applications of the Emergy Methodology conferences at the University of Florida brought together researchers working directly with emergy. The Gainesville meetings were deliberately oriented toward work in progress and new developments rather than simply completed research. They provided a setting in which H.T. Odum, colleagues, students, and visiting researchers could explore new concepts, question assumptions, compare methods, and refine both the theory and practice of emergy analysis. The proceedings preserve much of this development and provide an unusual record of ideas as they were being proposed and debated.
In an important sense, the conferences extended internationally the intellectual process that had characterized the Systems Seminars at the University of Florida. New ideas did not have to arrive as finished theories. They could be presented, questioned, calculated, revised, and presented again. As participation became increasingly international, responsibility for developing the field also became more widely distributed.
The conferences were part of a much broader international exchange. Increasing numbers of visiting scholars came to the University of Florida from Europe, Central and South America, Asia, Australia, and New Zealand. Particularly strong relationships developed with researchers in Italy, Sweden, Brazil, Taiwan, South Korea, and China, with an especially large number of Chinese scholars eventually participating in the work. Many visitors spent extended periods in Gainesville, participating in seminars and collaborative research as well as conducting their own analyses. At the same time, important centers of research were developing elsewhere. What had begun as a relatively concentrated research program was becoming an international network connected by common concepts, methods, projects, conferences, and continuing exchange.
The expanding research community also created a need to assemble and document the quantitative information on which emergy evaluations depended. In 2000 Odum initiated the Handbook of Emergy Evaluation: A Compendium of Data for Emergy Computation as a continuing series of folios. The objective was to bring together calculations of unit emergy values, their data sources, assumptions, and supporting notes in forms that other researchers could examine and use. Odum prepared the first folios; subsequent contributions by M.T. Brown and Eliana Bardi, S. Brandt-Williams, Patrick Kangas, and others extended the series to ecosystems, agriculture, landforms, and other subjects. The folios were intended not as a fixed table of accepted values but as a documented body of calculations that could be examined, compared, updated, and revised. That intent is stated explicitly in the folio series itself.
At the same time, Odum’s final years produced several major syntheses of systems ideas that had developed over the preceding decades. Ecological engineering increasingly emphasized self-organization and self-design: rather than attempting to construct and control every component of an environmental system, human activities could be coupled with ecological processes whose organization developed in response to available energies, materials, organisms, and environmental conditions. Self-organization, hierarchy, pulsing, and maximum power were increasingly understood as related aspects of the way systems develop and maintain organization.
A 2002 paper, “Explanations of Ecological Relationships with Energy Systems Concepts,” provided another kind of synthesis. Odum took the results of twelve recent ecological studies and interpreted them using Energy Systems Language and systems principles. Rather than focusing only on mechanisms operating at the scale of the organism or population, he placed those mechanisms within the larger systems of which they were part. Energy hierarchy, self-organization, and maximum empower provided the basis for explaining how processes at different scales were connected. In looking back on the development of the Energy Systems Language, Odum also noted that emergy and transformity had made explicit something that had been less apparent earlier: the left-to-right organization of energy systems diagrams represented not only a hierarchy of energy transformations, but also increasing scales of time and space.
Modeling provided another means of bringing these ideas together. From the earliest electrical analogs and energy circuit diagrams, Odum had used models to explore how system structure generated behavior. Increasing computer capability allowed those methods to evolve into graphical systems in which Energy Systems Language symbols could be connected and simulated. This development culminated in H.T. and Elisabeth Odum’s Modeling for All Scales: An Introduction to System Simulation in 2000. The book brought together the Energy Systems Language, simulation, and systems thinking as a means of understanding the dynamics of ecological, economic, and other systems. Modeling was not simply a technical exercise. Constructing a model required the investigator first to diagram the system, to define its boundaries and identify its sources, storages, pathways, interactions, and feedbacks, and then to ask whether the proposed structure could generate the behavior observed in the real system.
A second major synthesis was H.T. and Elisabeth Odum’s A Prosperous Way Down, published in 2001. Its development extended over many years, in part because its central argument ran counter to the prevailing expectation that economic development would continue through sustained growth and technological expansion. The Odums instead examined how societies might adapt to declining resource availability and economic contraction. The book brought together ideas developed through earlier work on energy, hierarchy, pulsing, resource use, and relationships between environmental and economic systems. Decline was treated not simply as failure, but as a phase of system dynamics requiring forms of organization appropriate to reduced resource availability.
The final major synthesis returned to a book Odum had published more than three decades earlier. He undertook a substantial rewriting of Environment, Power and Society, incorporating developments in systems thinking, energy hierarchy, maximum power, emergy, information, ecological engineering, and environmental accounting that had occurred since the original 1971 edition. The revision was not quite complete when he died in 2002. Mark Brown, Daniel Campbell, Elisabeth Odum, subsequently completed the editorial work, and at the request of Columbia University Press the revised book was published in 2007 as Environment, Power, and Society for the Twenty-First Century: The Hierarchy of Energy. The Emergy Society identifies the book among the foundational works of emergy.
By the beginning of the twenty-first century, much of the intellectual framework that Odum had developed over the preceding half century had been brought together in these later syntheses. At the same time, however, the expanding international community and the new Emergy Synthesis conferences meant that development of the field was no longer centered on Odum alone. His death in 2002 therefore marked the end of one period in the history of Systems Ecology and emergy, but not the end of their development.
Milestones and Key References
1998 — Advances in Energy Studies
The international Advances in Energy Studies meetings brought emergy into dialogue with a broader community studying energy, thermodynamics, environmental systems, and sustainability. Odum’s Emergy Evaluation from the 1998 meeting provides a useful primary document from this period and is preserved in the Emergy Society collection.
Key reference:
Odum, H.T. 1998. Emergy Evaluation. Advances in Energy Studies.
1999–2000 — The First Emergy Synthesis Conference
The first Emergy Synthesis meeting in Gainesville established a recurring international forum devoted specifically to the theory and applications of emergy. More than a venue for reporting finished applications, the conferences became places where theoretical and methodological questions could be explored and debated.
2000 — Handbook of Emergy Evaluation
Odum initiated the Handbook of Emergy Evaluation folio series to assemble unit emergy values together with the calculations, assumptions, and sources on which they were based. The series explicitly anticipated contributions by many authors and recognized that values could be revised as knowledge and the global baseline changed.
Key references:
Odum, H.T. 2000. Handbook of Emergy Evaluation, Folio #2: Emergy of Global Processes.
Brown, M.T., and E. Bardi. 2001. Handbook of Emergy Evaluation, Folio #3: Emergy of Ecosystems.
Brandt-Williams, S.L. 2002. Handbook of Emergy Evaluation, Folio #4: Emergy of Florida Agriculture.
Kangas, P. 2002. Handbook of Emergy Evaluation, Folio #5: Emergy of Landforms
2000–2003 — Major Late Syntheses
Odum’s final years brought together several major strands of his systems thinking. Modeling for All Scales (2000) integrated Energy Systems Language, systems diagramming, and simulation; A Prosperous Way Down (2001) applied systems principles to growth, resource decline, and economic contraction; “Explanations of Ecological Relationships with Energy Systems Concepts” (2002) demonstrated how energy systems theory could interpret ecological observations across scales; and Concepts and Methods of Ecological Engineering (2003) synthesized ecological engineering around self-organization and self-design, energy hierarchy, maximum power, and emergy.
Key references:
Odum, H.T., and E.C. Odum. 2000. Modeling for All Scales: An Introduction to System Simulation. Academic Press.
Odum, H.T., and E.C. Odum. 2001. A Prosperous Way Down: Principles and Policies.
Concepts and Methods of Ecological Engineering. H.T. Odum (2003)
2002–2007 — A Final Synthesis
Odum’s death in 2002 occurred before he completed the revision of Environment, Power and Society. Mark Brown, Daniel Campbell, and Elisabeth Odum, completed the editorial work, and the revised synthesis appeared in 2007 as Environment, Power, and Society for the Twenty-First Century: The Hierarchy of Energy.
Key reference:
Odum, H.T. 2007. Environment, Power, and Society for the Twenty-First Century: The Hierarchy of Energy. Columbia University Press.