The word ‘sustainable’ means maintainable or bearable. Hence sustainable development refers to that development which may be prolonged for a considerable period of time or which may be bearable by the system and the society. It refers to a type of development that meets the needs of the present generation, maintains same level of development for a longer period of time, conserves the existing resources for the future generation so that same level of development could continue and causes very little or no damage to the environment.
As the bio-physical system has a limit to assimilate input, output cannot be indefinitely raised. After a certain limit production not only becomes uneconomical but it causes damage to the environment. Accordingly the sustainable development has been defined as a production System in which technological and management inputs do not adversely affect the bio-physical system (Psychotherapy and Carpenter, 1991). Sustainable development of natural resources usually means exploitation of resources up to that Limit which could be recouped by the natural system and help In raising the quality of life of the people.
Hence, environment and human beings are the two sides of the same coin of sustainable development. The World Commission on Environment and Development established by the united Nations has defined sustainable development as “development that meets the needs of the present without compromising the ability of the future generations to meet their own needs. ” The essential needs of the world’s poor has been emphasized as the priority. Therefore, the two crucial objectives of sustainable development are: (I) satisfaction of basic human needs, and ensure survival of human beings and all living creatures.