Sustainable Development: Defining A New Paradigm (Aspects ,Perspectives )

    In 1987 the World Commission on Environment and Development sought to address the problem of conflicts between environment and development goals by formulating a definition of sustainable development: Sustainable development is development which meets the needs of the present without compromising the ability of future generations to meet their own needs.
Aspects f Sustainable Development
    World Commission on Environment and Development, 1987 In the extensive discussion and use of the concept since then , there has been a growing recognition of three essential aspects of sustainable development:
* Economic: An economically sustainable system must be able to
produce goods and services on a continuing basis, to maintain manageable
levels of government and external debt, and to avoid extreme sectoral
imbalances which damage agricultural or industrial production.
* Environmental: An environmentally sustainable system must
maintain a stable resource base, avoiding over-exploitation of renewable
resource systems or environmental sink functions, and depleting nonrenewable resources only to the extent that investment is made in adequate substitutes. 
    This includes maintenance of biodiversity, atmospheric stability, and other ecosystem functions not ordinarily classed as economic resources.
* Social: A socially sustainable system must achieve fairness in
distribution and opportunity, adequate provision of social services including
health and education, gender equity, and political accountability and participation.
These three elements of sustainability introduce many potential complications to the original, simple definition of economic development. 
Perspective Of Sustainable Development :
     Drawing on economic, ecological, and social perspectives, we can identify some of the main themes that are integral to the construction of a new paradigm:
* Economic sustainability requires that the different kinds of capital that make economic production possible must be maintained or augmented.
    These include manufactured capital, natural capital, human capital, and social capital. Some substitutability may be possible among these kinds of capital, but in broad terms they are complementary, so that the maintenance of all four is essential over the long term.
* The conservation of ecosystems and natural resources is essential for sustainable economic production and intergenerational equity. From an ecological perspective, both human population and total resource demand must be limited in scale, and the integrity of ecosystems and diversity of species must be maintained. Market mechanisms often do not operate effectively to conserve this natural capital, but tend to deplete and degrade it. 
* Social equity, the fulfillment of basic health and educational needs, and participatory democracy are crucial elements of development, and are interrelated with environmental sustainability. 
    Taken together, these observations suggest new guidelines for the development process. They also require modifications to the goal of economic growth. Economic growth in some form is required for those who lack essentials, but it must be subject to global limits and should not be the prime objective for countries already at high levels of consumption .
     In terms of sustainability, a moderate level of consumption, together with strong social institutions and a healthy environment, represents a better ideal than ever-increasing consumption . Sustainability, however, is more than limits on  population or restraint in consumption - though these are important. It means that the choice of goods and technologies must be oriented to the requirements of ecosystem integrity and species diversity as well as to social goals. Elements of all three perspectives – economic, ecological, and social – are essential to an understanding of the requirements for sustainability.
I. THE ECONOMIC PERSPECTIVE
    From the point of view of neo-classical economic theory, sustainability can be defined in terms of the maximization of welfare over time. (This isassumed to be human welfare – the claims of the non-human world arise when we consider the ecological perspective.) Most economists simplify further by identifying the maximization of welfare with the maximization of utility derived from consumption. While this may be criticized as an oversimplification, it certainly includes many important elements of human welfare (food, clothing, housing, transportation, health and education services, etc.) and it has the analytical advantage of reducing the problem to a measurable single-dimensional indicator.
   A formal economic analysis then raises the question of whether sustainability has any validity as an economic concept. According to standard economic theory, efficient resource allocation should have the effect of maximizing utility from consumption. If we accept the use of time discounting as a method of comparing the economic values of consumption in different time periods, then sustainability appears to mean nothing more than efficient resource allocation – a concept already well established in economics. 
   One line of criticism of this reductionist approach to sustainability centers on the use of discounting. At a discount rate of 10%, the value of *1 million one hundred years from now is the same as a mere *72 today. Thus it would apparently be justifiable to impose costs of up to *1 million on people in the year 2100 in order to enjoy *72 worth of consumption today. By this logic, much resource depletion and environmental damage could be considered acceptable, and even optimal, according to a criterion of economic efficiency.
   The problem is that the use of a discount rate implicitly imposes a specific choice regarding the relative welfare of present and future generations. Howarth and Norgaard have shown that the choice of a discount rate is equivalent to a choice of allocations among generations . Use of a current market discount rate gives undue weight to the preferences of current consumers. When we consider issues such as soil
erosion or atmospheric buildup of greenhouse gases, where the most damaging impacts are felt over decades or generations, this creates a strong bias against sustainability. Thus to achieve intergenerational equity, we must either impose a low discount rate or some kind of sustainability rule regarding resource use and environmental impacts. Cline (1992), for example, has suggested the use of a discount rate of 1.5% for balancing long-term costs and benefits of global climate change abatement.
    A strong sustainability approach is based on the idea that substitutability between natural and manufactured capital is limited. Rather, the two are seen as complements -- factors that must be used together to be productive. For example, a fleet of fishing boats is of no use without a stock of fish. In the case of critical natural capital - for example essential water supplies -- substitutability is close to zero. While it may be possible, for example, to compensate for some water pollution with purification systems, life and economic activity is essentially impossible without access to water. The strong sustainability approach implies that specific measures distinct from the ordinary market process are necessary for the conservation of natural capital. It also implies limits on macroeconomic scale. The economic system cannot grow beyond the limitations set by the regeneration and waste-absorption capacities of the ecosystem. 
    The distinction between weak and strong sustainability is discussed in Daly (1994). Strong sustainability is defended by Daly (1995) and criticized by Beckerman (1994, 1995), who rejects the concept of sustainability in general. A defense of weak sustainability is offered by El Serafy (1996), while Common (1996) argues that the distinction between weak and strong sustainability is invalid. Limitations of the weak sustainability concept are discussed by Gowdy and O’Hara (1997).
   Costanza and Daly (1992) suggest that a minimum necessary condition for sustainability can be expressed in terms of the conservation of natural capital. This policy goal leads to two decision rules, one for renewable and the other for non-renewable resources. For renewables, the rule is to limit resource consumption to sustainable yield levels; for non-renewables the rule is to re-invest the proceeds from non-renewable resource exploitation into renewable natural capital. Following these two rules will maintain a constant stock of natural capital. To maintain a constant per capita stock of natural capital also requires a stable level of human population, a factor which Daly has emphasized elsewhere .
   Toman (1992) proposes that the difficulty in defining sustainability may be resolved by recognizing that some issues can be appropriately dealt with through neo-classical market efficiency, while others require the application of Ciriancy-Wantrup’s (1952) concept of a ‘safe minimum standard’ approach to protect essential resources and environmental functions. He suggests that the criteria of possible severity and irreversibility of ecological damages should be used to decide which theoretical framework is more appropriate. 
   This perspective implies that criteria other than the strictly economic – in particular, principles drawn from the science of ecology – should be applied to problems of long-term sustainability.
II. THE ECOLOGICAL PERSPECTIVE
   Common and Perrings (1992) have suggested that the economic perspective of ‘Solow-sustainability’ needs to be complemented by an ecological approach of ‘Holling-sustainability’, following the work of Holling on the resilience and stability of ecosystems. Unlike economists, whose models provide no upper bound on economic growth, physical scientists and ecologists are accustomed to the idea of limits. 
   Natural systems must exist subject to the unyielding laws of thermodynamics, and the science of population ecology has explored the implications of these laws for living organisms. ‘Two of the fundamental axioms of ecological and evolutionary biology are that organisms are exuberantly over-productive, and that limits set by time, space, and energy are inevitably encountered’. In an ecological perspective sustainability must involve limits on population and consumption levels. These limits apply to all biological systems. While humans may appear to evade them for a time, they must ultimately accept the boundaries of a finite planet.
   However, this simple assertion of limits does not fully capture the contribution of ecologists to the discussion of sustainability. What Holling identifies as a third axiom of ecology has even more significant implications. 
   The third axiom ‘concerns processes that generate variability and novelty’ –the generation of genetic diversity and the resultant processes of evolution and change in species and ecosystems. 
   Genetic diversity gives rise to resilience in ecosystems. Resilience is the ‘bounce-back’ capacity that enables a system to respond to disturbances or damage. A forest ecosystem, for example, may recover from a pest infestation through an increase in the population of predators that control the pest, an expansion of species unaffected by the pest, or possibly a development of pest resistance in affected species. The patterns of response will be widely variable, but the essential integrity of the ecosystem will be preserved. The key to resilience is the existence of a wide variety of species, interacting with each other and providing a reservoir of genetic forms that provide the potential to adapt to changing conditions.
    For the ecologist, sustainability should be defined in terms of the maintenance of ecosystem resilience. This view of sustainability is clearly different from the human-centered conceptions put forward by the World Commission on Environment and Development and the consumption-based principles proposed by economic theorists. Common and Perrings suggest that ‘the concepts of Solow-sustainability and Holling-sustainability are largely disjoint. This implies that there may be no close relationship between economic efficiency and ecological sustainability’.
   In order to achieve ecological sustainability, it is likely to be necessary to modify current consumption preferences and production techniques which, while efficient in economic terms, threaten the ecological resilience of planetary systems.
III . THE SOCIAL PERSPECTIVE
  Advocates of sustainable development, as noted above, recognize the social component of development as an essential part of the new paradigm.
   A ‘human development’ approach emphasizing issues of basic needs and equity is well grounded in the history of economic theory. Anand and Sen (1996) point out that concerns for these dimensions of economic development start with the earliest economic theorists, and contrast the human development approach to the wealth maximization approach that has dominated modern economics.
   Basic needs and equity in development have been the focus of the United Nations Development Programme’s series of Human Development Reports. In addition to calculating the Human Development Index, which offers a different measure of development success from per capita GNP or GDP, the Human Development Reports focus each year on a different aspect of social and economic development, such as democratic governance (1993), gender inequity (1995), and poverty (1997).