The sun which brings we human being and ground living thing blessing provides harmful ultraviolet ray. When human being takes harmful ultraviolet ray, we suffer from skin cancer and are more likely to suffer from cataract (disease of eyes). In addition, resistance for disease becomes weak, too. Furthermore, it is said that plant or marine ecosystem include adverse effects as well as human being.
It is role of the ozone layer that it exists in the stratosphere we take in this harmful ultraviolet ray, and to prevent it from reaching ground. The ozone layer is barrier of the earth keeping ecosystem of human health and animals and plants.
However, quantity of ozone called ozone hole extremely decreased over the South Pole in 1985, and phenomenon that the ozone layer became thin was observed for the first time. We increase year by year, and the range becomes wider than the area of the Antarctic Continent after 1989.
Afterwards, including Japan, we understood that quantity of ozone decreased in all parts of the world.
We destroy the ozone layer
It is chemical substance including chlorine such as Freon that destroys the ozone layer.
Freon was used for our personal refrigerator or air-conditioner as refrigerant, and it was used as spray can. When this refrigerator or air-conditioner become garbage and are broken, Freon is released and rises before long to the stratosphere with the ozone layer and destroys the ozone layer.
Therefore production of strong Freon of work to destroy the ozone layer in 1996 was prohibited. With made refrigerator and spray can, thing which is hard to get the ozone layer out of order is used now. However, it is said that it takes long time so that Freon naturally decomposes as Freon is material with high stability. Therefore, it is expected that depletion of the ozone layer will continue in future for dozens of years by Freon released in the atmosphere so far.
The Southern Hemisphere distribution of ozone gross quantity mean for 1979, 2,001 years in month of each October
The Meteorological Agency makes data of NASA offer for the cause
To follow the ozone layer
"Vienna Convention" to cooperate globally in 1985, and to protect the ozone layer was established, and, in more 1987, international decision which included concrete regulation including prohibition of production, use of ozone depletion materials such as Freon as "Montreal Protocol" was adopted.
In Japan, "the ozone layer protection law" is established in 1988 and carries out international decision concretely.
Production of strong Freon of work to destroy ozone has been already canceled by these decisions. However, depending on type of Freon, there is thing which is not abolished totally by 2020. In addition, problem that there is many remains in global movement to protect the ozone layer still more because there are many countries which do not join Montreal Protocol.
Brochure (Ministry of the Environment) about the ozone layer (the outside site)
The ozone layer protection, warming measures (Ministry of Economy, Trade and Industry) (the outside site)
When want to discard Freon; about ... Freon collection (Environment Administration Division)