Atmospheric aerosols are liquid or solid particulate matters suspended in the air. They are highly populated in the lower atmosphere. However, the mid-atmosphere aerosols play significant roles in atmospheric science. Their distribution decreases with altitude. The sources of these particulate matters could be from anthropogenic or natural activities at the surface or within the atmosphere. The presence of these particulate matters in the Earth's atmosphere has significant impact (both positively and negatively) either directly or indirectly on human activities in particular and life on Earth in general. It is believed that carbonyl sulfide and sulfur dioxide are the main precursor gases for the formation of stratospheric aerosol layer. Atmospheric OCS is known to be the highest among the background aerosol sources due to its long atmospheric life time. The transport of this gas from troposphere to the stratosphere occurs mainly through the tropical tropopause. In the stratosphere, its photo-oxidation produces sulfur dioxide which latter converted to the background aerosol of hydrated sulfuric acid. This is the cause of acid rain which results in deforestation and climate change.