Anthropogenic air pollution sources

What one experiences today as atmosphere is a transient snapshot and result of its evolutionary history. Much of the development and present status was explained based both on scientific knowledge, and combined with established facts, even speculation. The planet Earth was formed around 4600 million years ago by the gravitational accretion of relatively small rocks and dust, within the solar nebula. The first evidence of single-celled life, for which tiny oxygen concentration was an essential prerequisite, is shown in the fossil record from around 3000 million years ago. Subsequently, the process of respiration led to a gradual increase in the atmospheric oxygen concentration. This in turn allowed the development of O3 which is thought to have been a necessary shield against solar UV. Subsequent evolution of the atmosphere has been dominated by the balance between production and consumption of both CO2 and O2 (Colls, 2002). Presently the lower part of the atmosphere is known as *air* and is formed by mainly nitrogen, oxygen and other gases, trace gases and particles. The composition, even if is suspected to major changes, is under the influence of the man kind evolution, both in terms of population number growth, as in industrial and agricultural and household development (in one word civilization). The energy consumption and technical evolution related to these sources is one main cause of the man made pollution, causing modification of the air quality, above limits, stipulated generously in legislation, adapted and modified according the to the level of knowledge, permanently. These anthropogenic pollution sources are exhausting diverse specific species to the free atmosphere and are stressing over the limit the natural possibility of the ecosystem to adapt or to cover these caused concentration augmentation. One has to notice that all the man made sources (from industry, agriculture, transportation, household sources, etc.) are contributing to the air quality level in addition to the natural sources, that existed since the Earth was created and in direct dependence to it. The population reached presently over 6 billion, is now forecast to reach 7.5 billion by 2020 and will be stabilize at approx. 9 billion by 2050. 90% of the future growth will occur in developing countries, and most of that will be concentrated in urban areas. By their nature, the air pollution sources can be classified, mainly, as physical, chemical and biological sources, secondly as natural and anthropogenic sources, further on climate change relevant or not. The physical pollution of the atmosphere is a consequence energy input like sound and heat energy. The most relevant physical pollution sources are the direct thermal pollution, natural or anthropogenic. The local climate is changed by heat 1