Global Warming Essay Example | Topics and Well Written Essays - 3250 words

Global Warming - Essay Example Sun is a continuous source of energy for our earth and its energy reaches the earth in form of electromagnetic radiations. A part of these radiations is absorbed by the outer atmosphere of the earth while the remaining is allowed to enter the lower atmosphere where life exists. The radiations reaching the lower atmosphere are the main source of energy for the organisms living here. Plants absorb this energy and convert it into chemical form which then supports the entire food chain. Humans have also learnt various methods to harness this energy to fulfill their requirements. The part of energy not utilized by humans or plants falls on different parts of dry land and oceans around the world. A very small amount of this energy is absorbed while most of it is reflected back into the atmosphere. The 30% of total energy is reflected back to the sun by the atmosphere and land. The remaining 70% which is initially absorbed by earth either leaves through direct radiation or through conductio n and convection of adjacent layers of air or through the latent heat of vaporization absorbed during cloud formation. Hence almost all the heat absorbed initially by earth is reflected back to the atmosphere. This heat energy which enters the atmosphere should ideally leave the atmosphere through radiation into the outer space. This natural process keeps the temperature of the earth stable within a certain range. Recently, due to human activity, the amount of gases such as carbon dioxide, nitrogen oxides, sulphur oxides and hydrocarbons in the atmosphere has increased substantially.