Scope of Environment
The environment consists of four segments as under:
1. Atmosphere: The atmosphere implies the protective blanket of gases, surrounding the earth:
(a) It sustains life on the earth.
(b) It saves it from the hostile environment of outer space.
(c) It absorbs most of the cosmic rays from outer space and a major portion of the
electromagnetic radiation from the sun.
(d) It transmits only here ultraviolet, visible, near infrared radiation (300 to 2500
nm) and radio waves. (0.14 to 40 m) while filtering out tissue-damaging ultra-
violate waves below about 300 nm.
The atmosphere is composed of nitrogen and oxygen. Besides, argon, carbon dioxide,
and trace gases.
2. Hydrosphere: The Hydrosphere comprises all types of water resources oceans,
seas, lakes, rivers, streams, reserviour, polar icecaps, glaciers, and ground water.
(i) Nature 97% of the earth’s water supply is in the oceans,
(ii) About 2% of the water resources is locked in the polar icecaps and glaciers.
(iii)Only about 1% is available as fresh surface water-rivers, lakes streams, and
ground water fit to be used for human consumption and other uses.
3. Lithosphere: Lithosphere is the outer mantle of the solid earth. It consists
of minerals occurring in the earth’s crusts and the soil e.g. minerals, organic matter, air and water.
4. Biosphere: Biosphere indicates the realm of living organisms and their interactions with environment, viz atmosphere, hydrosphere and lithosphere.