The first International Workshop "Advances in Energy Studies. Energy Flows in Ecology and Economy" (Porto Venere, Italy, 26/30 May 1998) was aimed at improving definitions of scales and boundaries, methods of analysis, policy initiatives and future research needs required to generate a balanced pattern of humanity and environment. The Workshop conclusion challenged the scientific community to reframe analyses in a ecological-economics framework and develop tools for decision makers. It was suggested that the basic objective should be to match the life-cycle dynamics of human development at different scales to the natural dynamics of renewable and non-renewable resources at those scales. In addition it was quite apparent that cross-comparison analyses should be performed using the various approaches to elaborate differences, similarities, and scales of applicability of each distinct methodology. And finally, joint research projects were called for, that directly illuminate the policy relevance and implications of energy analysis.

The second International Workshop "Advances in Energy Studies. Exploring Supplies, Constraints, and Strategies" (Porto Venere, Italy, 23-27 May 2000) was expected to not only make these cross comparison analyses, but move beyond them to the presentation of original scientific results related to energy supplies, constraints, and strategies. Splitting the workshop organization into topics was not intended to restrain scientific inquiry into the complex nature of energy problems that require issues be dealt with under several, system oriented, points of view. Instead, the workshop sought to enhance systemic understanding of the theoretical basis of energy and resource use as well as the development of policy and management tools to deal with economy and environment from a system perspective. The three main areas of interest that were identified addressed three well specified areas of concern by the scientific community and the public and were as follows:

SUPPLIES: development and evaluation of energy sources
The goal of this topic area was to present evaluations and analyses of when and at what space/time scales energy sources are effective, economically acceptable, and environmentally sound. Both energy sources and energy saving technologies, as well as availability and use of non-renewable sources should be evaluated in this framework. In addition to scientific and technological aspects, related to the state of development of a given technology, life-cycle assessments as well as integrated energy, environmental and economic cost assessments were sought as useful tools for evaluation and improvement.

CONSTRAINTS: environmental, economic and social
The goal for this topic area was to clarify the links between energy and resource use with other social, economic and environmental constraints such as: soil erosion, air pollution, global warming, clean water availability, and food supply. Also recognized as important constraints were increasing waste production in developed societies, cost and availability of raw resources, and limits to their use due to geographical concentration and market access. Finally, limits to efficiency, generalized quantitative indicators of constraints, and scale-related (local to global) constraints were stressed within this theme area.

STRATEGIES: policy and modeling tools
The goal of this theme area was to clarify and illustrate quantitative and qualitative tools for decision making. Examples of these tools might included: economic and energy scenarios, strategies for fossil fuel substitution, recycling and "zero emissions" strategies, evaluation of environmental services, problems of equity, environmental taxation policies, efficiency versus scale, downsizing of industrial societies to meet declining resource availability, and finally multi-criteria policy analysis

ORGANIZATION OF THE WORKSHOP
The workshop was organized around individual presentations by participants and four panel discussions. A total of 55 papers and posters where presented by scientists from Australia, New Zealand, Western and Eastern Europe, China, Japan, Canada, and the United States in 3 days of lectures with ample time for discussion. On the final day, workshop participants came together in a summary discussion session related to current trends, world futures, critical policy objectives and future research directions.

Papers and Posters

While it is difficult to categorize most papers and posters into a single theme, as they often dealt with more than one issue, the vast majority of presentations and posters dealt with "Strategies." About 35 of the 55 papers and posters were primarily concerned with methods and tools for public policy decision making. The remaining 20 papers and posters were equally split between the "Supplies " and "Constraints" themes.

In the Supplies theme area, presentations were related to the economics of renewable energy for electric production, and considerations of natural gas, hydrogen and biofuels as energy sources and carriers. Also considered were the effects of modernization of regional energy systems on future energy demand, including "thermo-economic" consideration of energy saving and energy supply technologies as well as cogeneration of heat and electricity.

Presentations in the "Constraints" theme addressed global fresh water supplies, energy availability as a constraint on economic development in less developed countries, evaluation of the relative contributions of energy, labor and creativity to economic growth, considerations of global warming, and global environmental impacts of resource use.

By far the majority of papers and posters dealt with "Strategies". Many presentations were devoted to the multidimensionality and complexity of environment/economic aspects of energy and resource use. Several presentations (five in all) approached the theme area by combining methods of analysis recognizing and stressing the strengths of methods such as life-cycle assessments, emergy analysis, and exergy accounting in the same framework. These papers suggested an integrated use of environmental assessment tools to take advantage of synergistic effects resulting from their combination and therefore providing an enhanced approach for decision making.

Exergy accounting was the subject of several presentations where monetary price and energy value were considered in the same framework, an exergy model of business cycles was proposed, and some theoretical aspects of exergy in living systems were presented.

Both theoretical and applied perspectives on emergy analysis as a policy decision making tool were discussed in several presentations. Emergy analysis techniques were applied to hydrogen fuel cells, water supply alternatives, solar cells, electric generation facilities, and soybean cultivation as demonstrations of its use in decision making.

Terms such as multi-criteria, multi-objective, multi-dimensionality and multi-scale were used to describe integrated assessment of sustainability in several presentations where it was suggested that "traditional" scientific investigations would have to give way to "post-normal" science in the face of the uncertainty surrounding global environmental decisions and issues of sustainable human activities.

Theme Panel Presentations
Four panel presentations were organized to discuss specific issues related to supplies, constraints, and strategies. The goal of the panels was to furnish examples of how scientists working at the interface of economy, ecology, and energy might stress a particular problem to improve knowledge and provide a support tool for public policy decision making. The panels stressed special topics related to the workshop themes as follows:

1) Hydrogen;
2) Ecosystem health;
3) The role of science in governance related to issues of sustainability;
4) Energy strategies consistent with ecological strategies.

A brief summary of each of the panel presentations follows:

Panel I: Perspectives on Hydrogen Energy and Fuel Cells
The panel dealt with energy, economic and environmental considerations supporting the hydrogen economy as a feasible option. The panel addressed such questions as…How reliable are these considerations and what is the range of their uncertainty? The panel discussed still unresolved problems of CO₂ sequestration, market penetration, and the technological development of fuel cells as well as comparisons of hydrogen energy to other alternatives like direct use of fossil fuels, nuclear, photovoltaic, etc. Finally the prerequisites required for hydrogen and fuel cells to compete in the energy market were also considered.

Panel II: Can we use energy based indicators to characterize and measure the status of ecosystems, human, disturbed and natural?
The panel discussed thermodynamics of ecosystems and how energy flow in ecosystems may change with development and in response to external stress. Measures related to the energy and mass flow structure of ecosystems and measures of the second law effectiveness of ecosystems were discussed. The use of surface temperature as a way of characterizing the organizational state of ecosystems was discussed in particular detail as a possible method to evaluate changes in ecosystem structure and organization

Panel III: The role that science has to play in the process of governance when dealing with the issue of sustainability
The panel explored questions pertaining to complex problems associated with decision making in the presence of insufficient data, high stakes, and a short time in which to act. Such subjects as the parallel tracking of changes of non-equivalent attributes of performance and incommensurability linked to the existence of different "value systems" in the stakeholders were discussed. The panel suggested these issues were posing new challenges for science, leading to the need for:: (1) using multicriteria methods of analysis; (2) parallel use of non-reducible indicators, (3) participatory techniques to involve stakeholders in the decision process.

Panel IV: Energy Strategies Consistent With Ecological Constraints.
The panel discussion addressed recent research which integrates three factors related to a long term energy strategy: 1). efficiency of use, 2). limits to total consumption rate, and 3). equity of access across nations and regions. In particular, the contradiction known as Jevon’s Paradox, where increased efficiency leads to increased consumption, was discussed. Characteristics of systems that are contracting in size and organization were given as a means of providing models of decession (the opposite of succession). The main questions that were addressed included…What are viable strategies that combine promoting increased efficiency with limits to consumption and equity? What is desirable? Possible? On what time scales? What are realistic expectations?

WORKSHOP GOALS AND OBJECTIVES

The challenge to scientists working at the interface of energy, ecology and economics that was posed during the final day of the first workshop was to reframe research endeavors within a structural ecological-economics perspective emphasizing a single economic system open to environment as source-sink. Additionally, it was considered imperative that cross comparison analyses be performed using the various approaches to illuminate the differences, similarities, and scales of applicability of each approach. Finally, it was suggested that projects were needed that directly illuminated the policy relevance and implications of energy analysis to sharpen the focus of and orient the field to provide real guidance mechanisms to the decision making system.

Our expectation for the second workshop was that it not only address these three things, but move beyond them to the presentation of original scientific results related to energy supplies, constraints, and strategies. Our goal was to enhance systemic understanding of the theoretical basis of energy and resource use as well as the development of policy and management tools to deal with economy and environment from a system perspective. To these ends, the workshop may have missed the mark. However, the expectation and goal were not missed entirely, and in fact it may be that the expectations and goals we set were simply too high. In reviewing the papers and the discussions that inevitably followed, it was apparent that while we missed the high mark we had set for ourselves, significant progress has been made since the last workshop.

Our call at the first workshop for restructuring of research to address a more systemic overview of economy, ecology, and energy was manifested in the dialog that developed at this second workshop involving cross discipline concepts of functionality, complexity, indices of success, normative standards, efficiencies, and goal functions, to name a few. There was a convergence of concepts, especially related to quality of energy and energy constraints on growth and development of systems. In all, there was agreement that systemic understanding of economy in light of energy constraints and ecological realities was still relevant and absolutely necessary. However, while there was much dialog concerning systems concepts, with only a few exceptions, we did not achieve a systems integrative view of economy, ecology, and energy.

Of primary interest and concern by nearly all participants at the first workshop, was the need to better understand the application domain of each of the various approaches. It was felt that it was necessary to illuminate these differences. In essence we had challenged ourselves to work together in cross comparison analyses, and in fact, several papers were presented that did accomplish this. However, the papers did not compare methodologies so much as they drew from the various methods, indices and normative standards and presented them together providing additional insights not gained with a single methodological approach. These papers went beyond simple comparison, by demonstrating complementarity of approaches. While the goal of cross comparisons was not achieved, the similarities between the methodologies became more evident, and, consequently, the acceptance of the methodologies was improved.

Acceptance not with standing, there was an apparent convergence of emergy and exergy approaches. There was a call for an accounting of "embodied" exergy, and a recognition that there is a need for exergy evaluation of information. The concept of exergetic cost was introduced and it was suggested "that we can appreciate entities if we know the effort needed to make them" (i.e., exergetic cost is a measure of the effort needed to make something). These directions in exergy theoretical research represent the beginnings of a convergence of exergy theory with that of emergy theory…in that:

1. emergy is a parallel concept with that of exergy cost;
2. there is a recognition of differences in forms of exergy [ie chemical, mechanical, informational], and
3. possibly a recognition that different forms of exergy cannot be added directly.

CONCLUSIONS AND RESEARCH PRIORITIES

• Call for multidisciplinary integration of approaches

• Much work is still needed on tools supporting decision making.

• Strategies that link our research and the energy production sector are still lacking

• Understanding of Environmental Constraints Required