Located in the atmospheric layer known as the stratosphere is a region of concentration of the ozone (O3) molecule. This “ozone layer” is found at an altitude of about 10 to 50 kilometers (6 to 31 miles), with a maximum concentration in the stratosphere at an altitude of approximately 25 kilometers (16 miles). Starting in the late 1970s, scientists began measuring a seasonal depletion of ozone in the ozone layer mainly at the South Pole. The ozone layer naturally shields Earth's life from the harmful effects of the Sun's ultraviolet (UV) radiation. The nation’s of the world have responded to this global environmental problem by proposing a plan known as the Montreal Protocol, to reduce and eliminate the use of chlorofluorocarbons (CFCs) the human-made chemical primarily responsible for ozone loss.
Sunlight is the electromagnetic radiation arriving at the Earth's surface due to direct illumination by the sun; this radiation includes ultraviolet, visible and...
Atmospheric scienceLast Updated on 2013-04-22 at 17:45
Atmospheric science is the umbrella term for the study of the atmosphere — the blanket of air covering the Earth. It is a relatively new discipline that is concerned... More »
SunLast Updated on 2013-02-10 at 16:43
The Sun is the ultimate source of energy for life on Earth, and it sustains nearly all aspects of human existence. The Sun is an ongoing hydrogen fusion... More »
OzoneLast Updated on 2012-08-21 at 22:15
Ozone is a gas made up of three oxygen atoms (O3). It occurs naturally in small (trace) amounts in the upper atmosphere (the stratosphere). Ozone... More »
Nuclear winterLast Updated on 2012-08-21 at 17:18
Nuclear winter is a term that describes the climatic effects of nuclear war. In the 1980's, work conducted jointly by Western and Soviet... More »
Molina, Mario J.Last Updated on 2012-08-21 at 16:32
Professor Molina has been involved in developing our scientific understanding of the chemistry of the stratospheric ozone layer and its susceptibility to human-made... More »