From Microsoft Encarta '98 deluxe CD-ROM
| The atmosphere is something we all take for granted but without it life on Earth would not exist as we know it! The atmosphere acts as a protective shield against the cosmic rays from the sun. The atmosphere absorbs most of these rays thereby protecting life forms from their damaging effects. One of the most important factors is that most of the ultra violet radiation is absorbed by the ozone layer thus protecting us from its harmful effects such as skin cancer. The atmosphere also absorbs infra red radiation which stabilises the earth's temperature. Without this effect the temperature on earth would be very hot in the day and very cold at night. This would mean that many animals and plants would not survive the huge diurnal temperature range. | From Microsoft Encarta '98 deluxe CD-ROM |
| The atmosphere is the source of life for plants and animals. It is a source of oxygen for all aerobic organisms while supplying carbon dioxide for photosynthesis in plants. All organisms are made of nitrogen containing proteins. The source of nitrogen in these proteins is the atmosphere. Nitrogen fixing bacteric bind the nitrogen so that other organisms can use it. |
The atmosphere also plays an important role in the hydrological and meteorological cycles. Unfortunately the atmosphere is also used as a dumping ground for pollutants. These pollutants change the characteristics of the atmosphere.
The atmosphere has many different chemical reactions occuring within it. This website explains the structure and compostion of the atmosphere and the reactions that occur. These links below take you to the relevent pages.