The gaseous composition of the Earth's atmosphere is changing at an accelerated rate because of the Influence of human activities. Different factors increase the air contamination by CO2. Understanding factors affecting atmosphere gaseous is important for managing and reducing air contaminants. The natural presence of the so-called 'greenhouse gases' (water vapor, carbon dioxide, nitrous oxides and methane) in the atmosphereis essential for life. Greenhouse gases trap heat in the lower atmosphere and keep the Earth far warmer than it would be without such gases. Over the Earth's long history, the concentration of these gases has markedly decreased. This decline has occurred due to complex transformation processes that operate at different time scales and involve transfer of materials between the three carbon reservoirs: atmosphere, land biosphere and oceans. However, over the past century human activities have been releasing greenhouse gases (GHGs) at a rate unprecedented in geologic time. As a consequence of this acceleration in the rate of emissions, the concentration of GHGs in the atmosphere has increased by 30%, since pre-industrial times.