The ozone layer, also called the stratosphere, has a primary function of absorbing ultraviolet sunlight. The absorption of ultraviolet rays has many effects, such as atmospheric temperature regulation and protection of biological entities.
When the ozone layer absorbs the sun's ultraviolet radiation, it creates a source of heat and regulates the temperature of the Earth's atmosphere. If the ozone didn't filter the sun's ultraviolet radiation, most of it would reach the Earth's surface, which would be dangerous for plants and animals. Researchers conducted experiments in which plants, animals and humans were exposed to ultraviolet radiation, and the results showed that the radiation had harmful results.
Within the ozone layer, ozone molecules are constantly formed and destroyed. The total amount of ozone usually remains stable but can vary with sunspots, the seasons and latitude. Scientists have established normal ozone levels during natural conditions and noticed that the ozone layer is being depleted due to external factors.
The main external factor that scientists are focusing on is the use of chlorofluorocarbons, or CFCs, in refrigerants, solvents and other applications. When CFCs break down, they release atomic chlorine, which can destroy over 100,000 ozone molecules per molecule of chlorine. Many experiments have shown that CFCs and other chemicals produce about 84 percent of the chlorine in the ozone layer. Measures taken to reduce CFCs have improved the ozone layer, and it is speculated that it will return to normal after many years.