The socio-cultural concept of sustainability seeks to maintain the stability of social and cultural systems, including the reduction of destructive conflicts. Elimination of poverty and intergenerational equity are important elements of this approach.
Conserving biological diversity is the foundation of ecologically sustainable development for three basic reasons, viz., biodiversity is essential to maintain the viability of ecological systems that support current production; future needs are unpredictable and potentially valuable species could be lost; and our understanding of ecosystems is insufficient to be certain of their role and to determine the impact of removing any component.
The loss of a critical ecosystem could have irreversible and catastrophic effects. Both human health and high agricultural productivity depend on the preservation of diverse biota consisting of an estimated 10 million species of plants and animals.
A generic procedure may be used to improve the quality of environmental decision-making in the power sector, in developing countries. In particular, where economic valuation of environmental impacts is difficult, multi- criteria analysis is used effectively.
The procedure may be applied to various types of environmental impacts, including terrestrial biodiversity loss due to hydroelectric projects, and damage to marine ecosystems in the case of thermal plants (Munasinghe, 1993).
The conservation of natural habitats and the protection of biological diversity is important for sustainable development at levels ranging from the global to the local. The increasing destruction of natural habitats in the second half of this century is primarily attributable to the increased burden of unsustainably managed human activity.
Improving the incomes and welfare of local communities, especially poor ones, while simultaneously preserving physical and biological systems, yield opportunities for developing countries to pursue the environmental, economic and social goals of sustainable development.
According to Munasinghe (1992, 1993), from the environmental economic viewpoint, there is a need to identify policy measures that will make market forces work more effectively to improve natural resource use by better aligning private and social costs and benefits, while also addressing the issues of inequity of distribution, especially those arising from differences between those who bear the costs of environmental degradation and those who are the beneficiaries.
The biodiversity crisis stems from the accelerated loss of the Earth’s productive capacity as driven by the activities of a growing human population. These forces are depleting the vast biological resource base of the Earth.
It appears that the tools and institutions are developing to address certain dimensions of the biodiversity issue. However, these efforts pale in the face of the enormous threats to biodiversity resulting from land use and atmospheric change driven by a burgeoning growth of the human population.
Some people may ask whether it really matters if an odd species or two disappears from a country or indeed from the earth. The answer to this question is both yes and no. Species disappear—they always have done and they always will. Charles Darwin had pointed out that plants and animals that are best able to cope with particular environments survive. Others vanish.
Conserving biodiversity does not mean making sure that the whole of nature looks exactly like it does today for an indefinite time to come. That is impossibility. The point is that the richness and variety of the natural environment—whether it be affected by human activities, or even basically man-made—should not be diminished.
Preserving species is only one aspect of the concept of biodiversity. Within any single species itself there is much genetic variation. This variation is vital if species are to develop and cope with a changing environment.
Furthermore, biological diversity includes variation in the way species are interrelated and how these relationships change. Interacting together, different species form ecosystems and underpin ecological processes, from photosynthesis to decomposition and recycling of nutrients.
The term biodiversity also refers to a multiplicity of ecosystems, habitats and landscapes. Thanks to the variety existing at these three levels, ecological processes are maintained even if ecosystems are subjected to some degree of disturbance.
We, as human beings, are involved in these ecosystems and depend on the processes they sustain. If they do not work as they should, neither will our lives and societies. We are taking serious risk when we erode biological diversity, since we know very little about the part played by each species in this ‘web of life’.
It is possible that a mere handful of key species would be enough to keep ecosystem processes going, but the question is, which? The human race has probably only discovered a fraction of all the species that exist. This is particularly true for species of insects and microorganisms.
The polymerase chain reaction (PCR) was discovered by Mullis (see Mullis, 1990). This reaction permits multiplication of DNA millions of times in a few hours, and is now fundamental to diagnostic medicine as well as much of biotechnology. It depends on a heat-resistant enzyme called Taq polymerase discovered by Thomas Brock in the bacterium Thermus aquaticus which occurs naturally in hot springs in Yellowstone National Park (Mullis, 1990).
The reaction exemplifies probably one of the most important and least recognized relationships between biodiversity and sustainable development, namely the great potential value of wild species. Biodiversity in essence represents the most fundamental library in support of the life sciences: millions of species endowed with unique sets of properties, processes and possible solutions to unique sets of biological histories and challenges— solutions that have evolved and survived to this moment.
Many others have occurred in the past and the number which might evolve in the future cannot be estimated. Yet those currently existing tell us interesting things about how evolution has worked and can work.
The discovery of the hydrothermal vent communities in the 1970s, which demonstrated that entire communities (of e.g. archaebacteria) could depend on the primal energy of the Earth rather than solar radiation and that organisms could exist at temperatures greater than the boiling point of water, demonstrate just how far we are from understanding even the most basic dimensions of life on Earth (Lovejoy, 1994).