Earth Environment and its spheres


In this article, the author has explained environmental chemistry, earth environment, and its components such as Atmosphere, lithosphere, hydrosphere, and Bio or ecosphere.

Environmental Chemistry

That branch of chemistry that deals with the chemicals and other pollutants in the environment is known as environmental chemistry.

It is a very important branch of chemistry which deals with the following topics.

  • Sources
  • Reactions
  • Transportation of chemicals
  • Transportation of toxic substances

No doubt these things are developed by human activities. In environmental chemistry, we also study the adverse effects of these things on human and other.

Relation of environmental chemistry with other branches of science

Environmental chemistry is related with all other branches of science. Some of these are as follows.

  • Biology
  • Physics
  • Medical
  • Agriculture
  • Public health
  • Sanitary engineering

Enviornment and its components

The enviornment is consisted of following components…

  1. Atmosphere
  2. Hydrosphere
  3. Lithosphere
  4. Biosphere or ecosphere

Let us discuss all of these in detail…

Earth Environment and its spheres
Earth Environment and its spheres

1: Atmosphere

The layer of gases surrounding the earth is known as atmosphere.

Composition of atmosphere

Atmosphere is composed of various gases in different proportions.

For example..

N278 %
O221 %
Ar0.9 %
CO20.03 %
Trace amountsH2, O3, CH4, CO, He, Ne, Kr, Xe
OthersWater vapours

The atmosphere is about 1000 km thick above the surface of the earth. Half the mass of the atmosphere is concentrated in the lower 5-6 km.

Radiation absorbed by atmosphere

Sunlight is consisted of variety of wavelengths. Some of the wavelengths are very dangerous for plants and animals. Atmosphere absorbs most of these cosmic  radiations. It also absorbs harmful electromagnetic radiations like UV rays.

 Which rays are not absorbed by the atmosphere?

Radiations from the sunlight whose wavelength lies between 1300- 2500 nm reach the eatth’s surface almost unabsorbed. The range of this wavelengths includes..

  • Near UV
  • Visible
  • Near Infrared

Benefits of gases of atmosphere

Gases present in the atmosphere are essential to maintain the life on the earth.

Some of the important benefits of theses gases are as follows.

  • Oxygen is  required for breathing
  • Carbon dioxide is required for plant photosynthesis.
  • Nitrogen is used by nitrogen-fixing bacteria to meet the demand for nitrogen for plants.
  • Water vapors are responsible for maintaining various forms of life on the earth.
  • Atmosphere maintains the hat balances of the earth.

2: Hydrosphere

Hydrosphere is that part of the enviornment whch includes all water bodies.

What is included in hydrosphere?

It includes all water resources..

  • Oceans
  • Rivers
  • Streams
  • Lakes
  • Polar ice caps
  • Glaciers
  • Ground water reservoirs

Oceans contain 97 % of the earth’s water. It has a high salt content. This water cannot be used for human consumptions due to the high percentage of salt in it.

Polar ice caps and  glaciers are consisted of 2 % of the earth’s total supply.

Fresh water includes surface water, Rivers, Lakes, streams and underground water. It is only 1 % of the total water which is used for agriculture (69%), industrial (23%)  and domestic (8 %) purposes.

3: Lithosphere

The lithosphere is the component of the environment which is consisted of the rigid rocky crust of the earth.

It makes most of the earth’s crust.

Composition of Lithosphere

Lithosphere has been composed of many elements present on the periodic table.

99.5 % of mass of the lithosphere consists of the following elements.

Oxygen46.6 %
Silicon27.72 %
Aluminium8.13 %
Iron5 %
Calcium3.63 %
Sodium2.83 %
Potassium2.59 %
Magnesium2.09 %
Ti, H2, P Less than 1%

Trace elements in lithosphere

There are some trace elements present in the lithosphere. These trace elements range from 0/1 to 0.2 %.

All these trace elements do not exist in free state. Rather these elements are present in the form of compounds as minerals. These compounds are crystalline in nature.


4: Biosphere or Ecosphere

The component of the environment that includes the region of the environment capable of supporting life is called the biosphere.

Biosphere consists of

  • Lower atmosphere
  • Oceans
  • Rivers
  • Lakes
  • Soils
  • Solid sediments

It is also known as ecosphere because it is related to the interactions of communities of organisms with the environment. This environment includes animals, plants, and microorganisms.