Ozone is one of the numerous atmospheric gases responsible for the development of life on the planet. It forms a thin layer in the atmosphere, where it would naturally be maintained. It’s specific role is the reflection of harmful ultraviolet (UV) rays coming from the Sun and outer space. When it comes into contact with chlorofluorocarbons (CFCs, a family of gases containing only chlorine, fluorine and carbon), the ozone is destroyed. When the ozone is destroyed, UV light can enter the Earth’s atmosphere and cause damage to ecosystems.
CFCs were used as a refrigerant and also as a propellant in aerosol cans. Their widespread use was largely due to the development in the Western nations during the mid-1900’s.
CFC’s were to blame for a large hole in the ozone layer above Antarctica, which threatened the icy region with damaging UV radiation. The CFC gases also reduced the overall thickness of the ozone layer, thereby allowing more cancer-causing UV radiation to reach the surface of the Earth.
As a result, international agreements were signed in an attempt to stop the emission of CFCs and similar chemicals, potentially reversing the damage already done. In 1987 all United Nations countries signed the Montreal Protocol, an agreement with the aim of halting the use of CFCs, with it being put into force in 1989.
Data gathered recently suggests that the ozone hasn’t just stopped depleting, but has in fact started growing. The ozone layer has started increasing in thickness, and the Antarctic “hole” has stopped growing – though it will take at least another ten years before it starts shrinking in size. It is believed that the reduction in use of CFCs was successful. It isn’t known, however, if the hole over the Antarctic will heal itself completely.
Although this is good environmental news, it is accompanied with data which suggested the level of greenhouse gases in the atmosphere had reached a record high. Many believe that there is still a chance for reducing emissions, though the fight will be a tougher one.
[Source: BBC Article]