"The emphasis of sustainable production is on the supply side of the equation, focusing on improving environmental performance in key transport. Sustainable consumption addresses the demand side, looking at how the goods and services required to meet basic needs and improve quality of life - such as food and health, shelter, clothing, leisure and mobility - can be delivered in ways that reduce the burden on the Earth's carrying capacity." Nick Robins and Sarah Roberts, Changing Consumption and Production Patterns: Unlocking Trade Opportunities. International Institute for Environment and Development and UN Department of Policy Coordination and Sustainable Development, 1997. Carrying capacity is the maximum number of individuals of a defined species that a given environment can support over the long term. The notion of limits is fundamental to the concept of carrying capacity. However, our limited understanding of complex, non-linear systems leads to uncertainty in calculating carrying capacity in relation to humans. Some argue that the concept is meaningless as free market conditions and technological innovation can extend limits indefinitely.
The steady state economy is a human economy characterized by constant population, capital stocks and rate of material/energy throughput such that there is sustainable equilibrium between human activities and the environment. While these elements are constant, "cultural capital" can change; thus a distinction is made between growth (quantitative) and development (qualitative).
Environmental utilization space or ecospace is the capacity of the environment to support human activities by regenerating renewable resources and absorbing waste. The boundaries of environmental utilization space are determined by the patterns and level of economic activity. A distributional element can be added by allocating ecospace at a national or per capita level, and is thus useful in illustrating present inequities.
Ecological footprint is the area of land and water required to support a defined economy or population at a specified standard of living. Industrialized economies are considered to require far more land than they have, thus, through trade, impacting on resources in other countries. Also known as 'appropriated carrying capacity', this concept also incorporates the distributional aspects of sustainable production and consumption.
Ecological rucksack is the total weight of material flow 'carried by' an item of consumption in the course of its life cycle. Like the ecological footprint, the ecological rucksack concept deals with displaced environmental impacts but has a more technical focus. It is concerned with reducing material intensity and resource inefficiency.
Eco-efficiency is the more iffy environmental impacts. This is widely considered a pragmatic approach, particularly among business, but it has been noted that improved unit efficiency does not necessarily lead to lower consumption levels. Economic output may rise with constant or reduced resource inputs.
MIPS (material intensity per service unit) is an indicator based on the material flow and the number of services or utilizations provided. Reducing the MIPS of a product is equivalent to increasing resource productivity.
Factor Four is the idea that resource productivity should be quadrupled so that wealth is doubled, and resource use is halved. The concept has been summed up as "doing more with less". It is argued that this would result in substantial macro-economic gains.
Factor Ten is the idea that per capita material flows caused by OECD countries should be reduced by a factor of ten. Globally, claim proponents, material turnover should be reduced by 50%, but because OECD countries are responsible for material flows five times as high as developing countries, and world population is inevitably increasing, the OECD has to set long-term targets well beyond the more conservative Factor Four target.
Natural capital is an extension of the economic notion of capital (manufactured means of production) to environmental 'goods and services'. It refers to a stock (e.g., a forest) which produces a flow of goods (e.g., new trees) and services (e.g., carbon sequestration, erosion control, habitat). Natural capital can be divided into renewable and non-renewable; the level of flow of non-renewable resources (e.g. fossil fuels) is determined politically.
Natural resource accounting and green GDP are alternative systems of national accounting and performance measures, which incorporate ecological and human welfare considerations. They are a way of better understanding the implications of economic activity for environmental integrity and human well-being. However, placing a monetary value on pollution and resource extraction is controversial and presents methodological difficulties.
Environmental debt is the cost of restoring previous environmental damage as well as the cost of recurring restoration measures. Unless measures are taken to alleviate environmental degradation, environmental debt continues to rise and the burden is transferred to future generations. However, some environmental damage such as species extinction is not restorable, and therefore cannot be included in the environmental debt.
Industrial ecology uses the metaphor of metabolism to analyze production and consumption by industry, government, organizations and consumers, and the interactions between them. It involves tracking energy and material flows through industrial systems, e.g. a plant, region, or national or global economy.
Inter-generational equity is the principle of equity between people alive today and future generations. The implication is that unsustainable production and consumption by today's society will degrade the ecological, social, and economic basis for tomorrow's society, whereas sustainability involves ensuring that future generations will have the means to achieve a quality of life equal to or better than today's.
Intra-generational equity is the principle of equity between different groups of people alive today. Similarly to inter-generational equity, intra-generational equity implies that consumption and production in one community should not undermine the ecological, social, and economic basis for other communities to maintain or improve their quality of life.
