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1. Toxins and carcinogens are considered dangerous from a human health point of view and are therefore commonly placed under strict control, irrespective of whether ecological consequences are likely or not.

2. Phosphorus is the other nutrient element that is required in amounts greater than the earth's crust normally contains. It is not recycled biologically, however, but accumulates on the ocean floors where it is recycled by ocean currents and by tectonic action. If the earth ever ceased to be tectonically active, the land surface would eventually run out of phosphorus.

3. Agreeing on the common use of simple and crude measures is nothing new. The gross domestic product (GDP) has been used for decades as a measure of "welfare," despite serious doubts that it really measures any such thing. It omits important sectors. including subsistence agriculture and unpaid household work (mostly by women), and it omits environmental services. On the other hand, it includes dubious items, such as "defensive measures" to protect health and safety, despite the fact that the health and safety hazards result from human activity in the first place. Clearly, defensive expenditures make no contribution to net social welfare. Nevertheless, GDP is still being used by macroeconomists, almost universally, without any of the adjustments or corrections that numerous critics have advocated.

4. The Wuppertal calculations of mass moved, or mass disturbed, generally include more than material "inputs" in the strict sense. The difference may be quite significant in some cases.

5. For a more complete review of this controversy, see Ayres (1993).

6. It is unclear what should be meant by "middle class." To put a specific monetary equivalent on it seems futile. A more functional suggestion might be that the relevant criterion of middle-class-ness is that children do not contribute to the family income, but rather constitute a financial obligation.

7. Some scientists argue that organic synthesis of a sort may have been going on in the reducing atmosphere of the early earth by mechanisms as yet unknown.

8. The argument for "factor 4" is set forth in German by von Weizsacker et al. (1995); the argument for "factor 10" is summarized in Schmidt-Bleek (1994).

9. The phrase "closed cycle" should not be taken literally. Closure with respect to materials is possible, but the cycle cannot be closed with respect to exergy.

10. The "second-law" efficiency of any process is defined as the ratio of the minimum amount of energy theoretically needed for the process to the energy actually used. It can be defined consistently, in principle, for any process (given a suitable convention on the treatment of co-inputs and byproducts), although actual numerical determination can be difficult in some cases. It must be pointed out that there is another widely used definition of efficiency, namely the ratio of "useful" energy outputs to total energy inputs. In some cases, such as electric power generation, the two definitions are equivalent. However in other cases (such as heating units) there is a very big difference. Gas furnaces are often advertised as having "efficiencies" up to 90 per cent, which merely means that 90 per cent of the heat is "useful" and only 10 per cent is lost with the combustion products. However, it often happens that the same amount of final heating effect could have been achieved with much less energy expenditure (e.g. by means of a "heat pump"). In this sense, most heating systems are actually very inefficient.

11. Note that efficiency of use is quite independent of the amount of use. The United States uses far more energy per capita than India, for instance, because it receives more energy services. But many energy using activities in India, from electric power generation to cooking, nevertheless tend to be considerably less efficient than their Western counterparts.

12. For a more detailed review of this literature, see Ayres (1994).

13. This issue was highlighted in the 1994 White Paper, Growth, Competitiveness, Employment - The Challenges and Ways Forward into the 21st Century, issued by Jacques Delors, then Chairman of the European Commission (EC 1994).


Ayres, Robert U. (1978) Resources, Environment and Economics: Applications of the Materials/Energy Balance Principle. New York: Wiley.
- (1989) Technological transformations and long waves. Journal of Technological Forecasting and Social Change
36(3).- (1990) Energy conservation in the industrial sector. In: N. A. Ferrari, J. W. Tester and D. O. Woods (eds.), Energy and the Environment in the 21st Century. Cambridge, MA: MIT Press.
- (1993) Commentary: Cowboys, cornucopias and long-run sustainability. Ecological Economics 8: 189-207.
- (1994) On economic disequilibrium and free lunch. Environmental and Resource Economics 4: 435-454.

Ayres, Robert U. and Leslie W. Ayres (1996) Industrial Ecology: Closing the Materials Cycle. Aldershot, UK: Edward Elgar.

Ayres, Robert U. and Allen V. Kneese (1971) Economic and ecological effects of a stationary economy. Annual Review of Ecology and Systematics 2, April.
- (1989) Externalities: Economics and thermodynamics. In: F. Archibugi and P. Nijkamp (eds.), Economy and Ecology: Towards Sustainable Development. Netherlands: Kluwer Academic Publishers.

Barnett, Harold J. (1979) Scarcity and growth revisited. In: V. K. Smith (ed.), Scarcity and Growth Reconsidered, pp. 163-217. Baltimore and London: Johns Hopkins University Press for Resources for the Future.

Barnett, Harold J. and Chandler Morse (1962) Scarcity and Growth: The Economics of Resource Scarcity. Baltimore, MD: Johns Hopkins University Press.

Boulding, Kenneth E. (1966) Environmental quality in a growing economy. In: H. Jarrett (ed.), Essays from the Sixth RFF Forum. Baltimore, MD: Johns Hopkins University Press.

Brundtland, G. H. (ed.) (1987) Our Common Future. New York: Oxford University Press.

Cole, H. S. D. et al. (eds.) (1973) Models of Doom: A Critique of the Limits to Growth. New York: Universe Books.

Commoner, Barry (1971) The Closing Circle. New York: Alfred Knopf.
- (1976) The Poverty of Power. New York: Bantam Books.

Daly, Herman E. (1990) Toward some operational principles of sustainable development. Ecological Economics 2:1-6.

EC (European Commission) (1994) Growth, Competitiveness, Employment The Challenges and Ways Forward into the 21st Century. White Paper. Luxembourg: Office for Official Publications of the European Communities.

Edmonds, Jae A. and J. M. Reilly (1985) Global Energy - Assessing the Future. New York: Oxford University Press.

Ehrlich, Paul (1968) Population Bomb. New York: Ballantine.

Ehrlich, P. H. and A. H. Ehrlich (1970) Population, Resources, Environment: Issues in Human Ecology. San Francisco: W. H. Freeman.

Frosch, Robert A. and Nicholas E. Gallopoulos (1989) Strategies for manufacturing. Scientific American 261(3): 94-102.

Gilland, Bernard (1983) Considerations on world population and food supply. Population and Development Review 9, July: 203 211.

Goeller, H. and Alvin Weinberg (1976) The age of substitutability. Science 191, February.

Goldemberg, Jose (1990) Energy and environmental policies in developed and developing countries. In: N. A. Ferrari, J. W. Tester, and D. O. Woods (eds.), Energy and the Environment in the 21st Century. Cambridge, MA: MIT Press.

Goldemberg, Jose et al. (1987) Energy for Development. Research Report, Washington, D.C.: World Resources Institute, September.

Holmberg, John, Karl-Henrik Robèrt, and Karl-Erik Eriksson (1995) Socio-ecological principles for a sustainable society: Scientific background and Swedish experience. In: J. Holmberg (ed.), Socio-Ecological Principles and Indicators for Sustainability. Göteborg: Institute of Physical Resource Theory.

Hoyle, Fred and N. Chaudra Wickramasinghe (1978) Life Cloud. New York: Harper & Row.

Jorgenson, Dale W. and Peter J. Wilcoxen (1990a) Intertemporal general equilibrium modeling of U.S. environmental regulation. Journal of Policy Modeling 12, Winter: 715 755.
- (1990b) Environmental regulation and U.S. economic growth. RAND Journal of Economics 21, Summer: 314 340.

Kahn, Herman, William Brown, and L. Martel (1976) The Next 200 Years A Scenario for America and the World. New York: William Morrow.

Keyfitz, Nathan (1990) Population growth can prevent the development that would slow population growth. In: J. Matthews (ed.), Preserving the Global Environment: The Challenge of Shared Leadership, pp. 39-77. New York: W. W. Norton.
- (1991) Population and development within the ecosphere: One view of the literature. Population Index 57(1): 5-22.

Lovelock, James E. (1972) Gaia as seen through the atmosphere. Atmospheric Environment 6: 579-580.
- (1979) Gaia: A New Look at Life on Earth. London: Oxford University Press.

Lovins, Amory B. et al. (1981) Least-Cost Energy: Solving the CO2 Problem. Andover, MA: Brickhouse Publication.

McNeill, James (1989) Strategies for sustainable economic development. Scientific American 261(3).

Manne, Alan S. and Richard G. Richels (1990) CO2 emission limits: An economic cost analysis for the USA. The Energy Journal 11(2): 51-74.
- (1992) Buying Greenhouse Insurance. Cambridge, MA: MIT Press.

Matthews, Jessica (1990) The great debate l: The world environmental crisis. Futures Research Quarterly 6(1).

Meadows, Dennis et al. (1972) The Limits to Growth: A Report for the Club of Rome's Project on the Predicament of Mankind. New York: Universe Books.

Mills, Evan, Deborah Wilson, and Thomas B. Johansson (1991) Getting started: No regrets strategies for reducing greenhouse gas emissions. Energy Policy, June.

Nakicenovic, Nebojsa, Luigi Bodda, Arnulf Grubler, and Paul V. Gilli. (1990) Technological Progress, Structural Change and Efficient Energy Use: Trends Worldwide and in Austria. Luxenburg, Austria: International Institute for Applied Systems Analysis. Also published in German in Schriftenreihe der Forschungsinitiative des Verbundkonzerns, vol. 6, Vienna, 1990.

Nakicenovic, Nebojsa, Paul V. Gilli, and Rainer Kurz (1996) Regional and global exergy and energy efficiencies. Energy 21.

Nordhaus, William (1994) Managing the Global Commons: The Economics of Climate Change. Cambridge, MA: MIT Press.

Pearce, David W. (1988) Economics, equity and sustainable development. Futures 20, December: 598-605.

Pearce, David W., Anil Markandya, and Edward Barbier (1989) Blueprint for a Green Economy. London: Earthscan.

Pezzey, John (1989) Sustainability, Intergenerational Equity and Environmental Policy. Discussion Paper in Economics 89-7. Boulder, CO: Department of Economics, University of Colorado, Fall.

Prigogine, llya and Stengers, I. (1984) Order out of Chaos: Man's New Dialogue with Nature. London: Bantam Books.

Repetto, Robert (1985) Natural resource accounting in a resource based economy: An Indonesian case study. Paper presented at the 3rd Environmental Accounting Workshop, sponsored by UNEP and the World Bank, Paris, October.

Sant, R. W. (1979) The Least-Cost Energy Strategy: Minimizing Consumer Costs through Competition. Report 55. Virginia: Mellon Institute Energy Productivity Center.

Schipper, Lee (1989) Energy efficiency in an era of apparent energy stability: Progress, plateau, or passé? In: International Energy Workshop. Laxenburg, Austria: International Institute for Applied Systems Analysis, June.

Schlesinger, William H. (1991) Bio-geochemistry: An Analysis of Global Change. New York: Academic Press.

Schmidt-Bleek, Friedrich B. (1992) Eco-restructuring economies: Operationalizing the sustainability concept. Fresenius Environmental Bulletin 1(46).
- (1994) Carnoules Declaration. Wuppertal, Germany: Factor Ten Club, October.

Simon, Julian (1980) Resources, population, environment: An oversupply of false bad news. Science 208, 27 June: 1431-1437.

Solow, Robert (1986) On the intergenerational allocation of natural resources. Scandinavian Journal of Economics 88: 141-149.
- (1992) An almost practical step towards sustainability. Invited Lecture on the Occasion of the 40th Anniversary of Resources for the Future. Washington, D.C.: Resources for the Future, 8 October.

Stigliani, William D. (1988) Changes in valued "capacities" of soils and sediments as indicators of non-linear and time-delayed environmental effects. Environmental Monitoring and Assessment 10: 245-307.

Tietenberg, Tom (1984) Environmental and Natural Resource Economics. Glenview, IL: Scott, Foresman.

Weizsäcker, Ernst Ulrich van, Amory B. Lovins, and L. Hunter Lovins (1995) Faktor Vier. Munich: Droemer Knaur.

Weterings, R. and J. B. Opschoor (1992) The Eco-capacity as a Challenge to Technological Development. Rijswijk, Netherlands: Advisory Council for Research on Nature and Environment, Publication RMNO 74a, April.
- (1994) Towards Environmental Performance Indicators Based on the Notion of Environmental Space. Rijswijk, Netherlands: Advisory Council for Research on Nature and Environment, Publication RMNO 96, March.

World Bank (1992) World Development Report. New York: Oxford University Press.

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