We use the biophysical environment in three different ways. First, the environment is the storehouse of all our material wealth (environment as source). Some of these resources, such as sunlight, air and water are inexhaustible. Others are either renewable (all the living entities that have the capacity for growth and reproduction) or non-renewable (fossil fuels, for example).
A special category for non-renewable resources is called recyclable resources, which would include many metals.
This classification is indicative of the way these resources should be utilized and managed for conservation. Secondly, we use the environment as a conduit for transportation and communication (as a medium). Land, water and air are put to service for movement of material goods, communication, dissemination and exchange of news, views and messages. Finally, the environment provides us with the “free” and easily available dumping ground for all the disposables – solid waste, liquid and gaseous effluents, and particulate matter (environment as sink).