Everything which surrounds us is collectively called as the environment.
Environment forms a life supporting system for us, since, it is from the environment that we get food to eat, water to drink and air to breathe and all requirements of day to day life.
In other words, we can say that the basic needs of human life are fulfilled by the materials available in the nature. These materials are air, water, soil, minerals, coal, petroleum, animals and plants.
These stocks of nature, which are useful to mankind, are called natural resources. Human beings use various natural resources for their requirements for example, we require timber or wood for furniture, this timber is obtained from teak trees which grows in the forest.
Man hunted animals to get their food, horns or bones, hides, feathers and teeth for various purposes. Various modes of human advancements such as growing population, agriculture, industrialization and urbanization have put pressure on the mankind to over exploit the natural resources.
Natural resources can be classified into two categories:
1. Renewable resources.
2. Non-renewable resources.
1. Renewable resources:
These resources are present in unlimited quantity in the nature and having the capacity to get replaced by quick recycling through natural cycles. Oxygen, in air is renewable resource because it is replaced by the plants by the process of photosynthesis. Some of the other renewable resources are solar radiation, water and atomic power. However, these resources can be exhausted if used too rapidly by improper management and they do not get enough time for renewal.
2. Non- renewable resources:
The stock of these resources are limited in nature. These resources once used cannot be replaced within a reasonable time. Some of non-renewable resources are soil, forests, wild animals, minerals, fossil fuel (coal, petroleum) for example, mineral deposits of fossil fuels are formed slowly over millions of years, if they are once used cannot be regenerated.