The earth is the only known planet, on which life exists. The composition of the atmosphere and the way its gases interact with electromagnetic radiation determine the atmosphere’s effect on energy from the Sun—and vice versa. The present condition and properties of earth’s atmosphere are one of the main reasons for earth to support life. Atmosphere is a gaseous layer surrounding the earth. In other words, we can say that our earth is surrounded by a thin layer of gases, called atmosphere. The atmosphere is special because it contains life-sustaining oxygen in large quantities. In fact, it took millions of years to reach the present condition by various processes. Along with its development, life came into existence and evolved. Today human actions are altering key dynamic balances in the atmosphere. Most importantly, humans are increasing greenhouse gas levels in the troposphere, which raises Earth’s surface temperature by increasing the amount of heat radiated from the atmosphere back to the ground. Carbon dioxide is emitted by all living organisms as an end product of respiration. This carbon dioxide, in turn is used by producer organisms for the synthesis of food. This is another example how natural processes are inter-related and inter-dependant.

This book ‘Atmosphere’ discovers the fundamental processes that cause atmospheric circulation and create climate zones and weather patterns, and learn how carbon cycling between atmosphere, land, and ocean reservoirs helps to regulate Earth’s climate. As a large amount of carbon dioxide is utilized by plants, on average, it comprises only 0.04 percent of dry air. Nevertheless, it plays significant role in keeping the atmosphere at temperatures that permit life. The concentration of carbon dioxide, nowadays, is increasing due to human activities. Today, man burns large quantities of fossil fuels for various purposes. As a result, huge amounts of carbon dioxide are emitted into the atmosphere. Its ever increasing concentration has already resulted in global warming and in some places, melting of ice.