A focus on efficiency is a natural consequence of ecosystem ecology' s focus on energy and material flows. Ecosystem ecology provides a theoretical foundation for a number of efficiency concepts. Ecological interpretations of efficiency derive primarily from three sources; Odum's ( 1 959) ecological efficiencies 'between and within trophic levels', Roward Odum's transformity and the maximum power principle. The interrelationships between these concepts are shown in the diagram below.
From
Ecological ejjiciencies -Trophic level energy intake effx:iency I
- Trophic level assimi1ation effICiency I - Trophi:: level production effx: iency
- Utilisation effx:iency
-Tissue growth or production effICiency
- Assimi1ation effx:iency - Ecologi::al growth effx:ienc y
Transformity
Maximum
power principle
Ecosystem ecology
Key:
_ = solid arrows show relationships between effx:ienc y concepts
= effICiency concepts covered in text
Figure 4-13: Interrelationships between ecosystem ecology efficiency concepts
An ecosystem ecology perspective provides several in sights into eco-efficiency. These are summarised in the table below:
Table 4-6: Insights and lessons for eco-efficiency from an ecosystem ecology perspective Ratios within and
between trophic levels Transformity
and lessons for
Efficiency is defined in terms of energy and matter flows;
Focuses on ecosystem service use by primary industrylbiological seetors of the eeonomy;
It is important to account for energy quality in eeo-efficiency; It is important to account for 'indirectness' in eeo-efficiency; Maximum
principle
power The level of eeo-efficiency is a function of evolution;
Assumptions
4.5 Conclusions
Systems are selected to operate at the eco-efficiency that generates maximum power;
Eco-efficiency analyses require a judicious mix of scales; Boundary definition is important;
Evolutionary change and eco-efficiency relationship is a conjecture only;
The functionalist approach ignores some of the complex interactions in a
This chapter has attempted to illuminate the insights into eco-efficiency from the three core disciplines of ecological economics. It has done this by placing the discussion in a theoretical analysis. Such a theoretical discussion has hitherto been neglected in eco-efficiency related literature.
This chapter has established that eco-efficiency has a core, or 'timeless' meaning, i.e. a constancy of meaning that exists throughout the different contexts. This core meaning is overlaid and hidden by disciplinary accretions and must be uncovered through etymological and contextual analysis. The core meaning of eco-efficiency could be "a measure of the success (accounting for environmental impacts) of economic activities aimed at promoting sustainable development that is quantified as the ratio of useful outputs to ecological inputs".
From a context-specific perspective, the efficiency concept has multiple interrelated interpretations. These different interpretations depend critically on the academic discipline of the interpreter. The interrelationships are summarised by combining Figure 4-4, Figure 4-9, and Figure 4-1 3 together into Figure 4-14 below.
Each of these efficiency concepts potentially provides a unique perspective and insights into eco-efficiency. The range of in sights into how each discipline would approach the eco efficiency concept are many and varied. Also, all perspectives of eco-efficiency are coloured by the epistemological assumptions that underpin each academic discipline. These insights and assumptions are summarised in the table below.
Table 4-7: Summary of insights and lessons for eco-efficiency from classical thermodynamic, neoclassical economic and ecosystem ecology theories
and lessons for
Classical thermodynamic theory
Thermal efficiency Provides a formulation for eco-efficiency concepts as the ratio of useful
energy output to inputs;
Efficiency measures
based on ideal limits
Finite-time efficiency Efficiency measures adjusted for energy quality
Assumptions
Emphasises that there are limits to eco-efficiency;
Useful for identifying the theoretical savings that can be achieved in eco efficiency;
Useful for identifying the proximity to eco-efficiency limits;
Emphasises the trade-off between efficiency and speed of transformation;
Highlights the importance of energy quality;
Emphasises that useful work should form the basis for an eco-efficiency that accounts for energy quality;
Nature is controllable therefore eco-efficiency is controllable; Eco-efficiency is focused on machines of work;
Equilibrium implies the level of eco-efficiency is computable and unique; The motives for pursuing eco-efficiency are both limited resources and a decrease in entropy generation;
Neoclassical economic theory
Neoclassical economic production theory Technical efficiency Production efficiency x-efficiency Neoclassical welfare economics AlIocative efficiency Intertemporal efficiency Assumptions
Focuses on the efficiency of the production process;
Focuses on those inputs and outputs that are commodified as part of the production function;
Focuses on direct inputs and outputs; Emphasises on technology.;
Emphasises the need to consider prices when allocating resources; Focuses on profit objective;
Helps to identify why the firm is not on the outermost production possibility frontier (perhaps because of unnecessary waste that has not been eliminated); Helps to identify waste reduction that can be achieved;
Eco-efficiency should be focused on arranging resources to maximise welfare;
Eco-efficiency would add emphasis to the importance of internalising externalities;
Rational consumers do consider time in their decisions to use natural resources, and these decisions are influenced by interest rates;
Eeo-efficiency achieved when the 'right context' is set;
Predictive statements about eco-efficiency are appropriate in an equilibrium world;
Atomistic focus implies that neoclassical economic approach to eco efficiency ignores wider system interdependencies;
Assumed reduced importance of the physical environment implies that eco efficiency is less important than other efficiency concepts;
Focus on can be commodified;
Time and scale issues are not
Ecosystem ecology theory
Ratios within and Efficiency is defined in terms of energy and matter flows;
between trophic levels Focus on ecosystems service use by primary industryfbiological sectors of the economy;
Transformity
Maximum power principle
Assumptions
It is important to account for energy quality in eco-efficiency; It is important to account for 'indirectness' in eco-efficiency;
The level of eco-efficiency is a function of evolution;
Systems are selected to operate at the eco-efficiency that generates maximum power;
Eco-efficiency analyses require a judicious mix of scales; Boundary definition is important;
Evolutionary change and eco-efficiency relationship is a conjecture only; The functionalist approach ignores some of the complex interactions in a
Together, the many different potential perspectives of eco-efficiency provide a rich tapestry with which to address the efficiency of economic-environmental interactions. This multi dimensional nature of eco-efficiency presents a challenge for those concerned with improving eco-efficiency. A conundrum now exists; what is the best way forward for improving our understanding of eco-efficiency? Should a single definition be pursued, or is a pluralistic approach to eco-efficiency most appropriate for understanding the concept? The next chapter addresses this issue and presents an ecological economic conceptual framework for understanding eco-efficiency in a broad context.
Iocative efficiency
Ma�age.!:i:!1 �ffi<:!e!I0'1
Welfare Economics Production Theory
Neoclassical economics
Figure 4-9
Key:
---..
1 - - - ,
Efficiency measures adjusted for energy quality using: - Gibbs free energy
- Helmholtz free energy
Ec:% gim/ effi";mdes
-Trophic level energy intake efficiency
- Trophic level assimilation efficiency - Trophic level production
efficiency - Utilisation effic iency -Tissue growth or production
efficiency
- Assimilation efficiency
- Ecological growth efficiency
Transformity - Exergy Maximum power principle Classical Thermodynamics Figure 4-4
= solid arrows show relationships between efficiency c oncepts
= efficiency concepts covered in text
= efficiency concepts not covered in text
Ecosystem ecology Figure 4- 1 3
Figure 4-14: The interrelationships between the multiple efficiency concepts from classical thermodynamics, neoclassical economics and ecosystem ecology