Nature. Nature has given us everything. God made so much for us and observing these things, it's all for a reason. This whole universe and all the amazing laws of nature are all made for a reason. God provided us these things so that we can live with great ease, from gravitation to ozone layer. But the question is are we only using these resources. No, we are exploiting them. There comes the need of sustainable development.

Ozone layer is a shield protecting earth from harsh ultraviolet radiation. These radiation can cause skin diseases like skin cancer. The Ozone layer is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet radiation. It contains high concentrations of ozone (O3) in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere. The ozone layer contains less than 10 parts per million of ozone, while the average ozone concentration in Earth's atmosphere as a whole is about 0.3 parts per million. The ozone layer is mainly found in the lower portion of the stratosphere, from approximately 20 to 30 kilometers (12 to 19 mi) above Earth, although its thickness varies seasonally and geographically. In 1976 atmospheric research revealed that the ozone layer was being depleted by chemicals released by industry, mainly chlorofluorocarbons (CFCs). Concerns that increased UV radiation due to ozone depletionthreatened life on Earth led to bans on the chemicals, and the latest evidence is that ozone depletion has slowed or stopped. The United Nations General Assembly has designated September 16 as the International Day for the Preservation of the Ozone Layer.


Since about 1975, scientists have detected a severe drop in ozone concentration in the layer over the Antarctica each spring. The situation then reached an alarming scale in 1987 when an international expedition found that half of the Antarctica's ozone have disappeared over a region twice the size of the United States, creating an enormous "hole" in the ozone layer.  Concentrations of ozone fell by as much as 50% of the norm at altitude of 18 km.  At mid-latitudes in the Northern Hemisphere, up to 3% decrease in ozone concentration was also observed.

 


What can we do?

*Buy air-conditioning and refrigeration equipment that do not use HCFCs as refrigerant.

*Buy aerosol products that do not use HCFCs or CFCs as propellants.

*Conduct regular inspection and maintenance of air-conditioning and refrigeration appliances to prevent and minimize refrigerant leakage.

*For existing air-conditioning and refrigeration appliances that operate on HCFCs or CFCs, the refrigerant should be recovered or recycled whenever an overhaul of equipment is to be carried out. Replacing or retrofitting such equipment to operate on non-HCFCs refrigerant should also be considered.

* When motor vehicle air-conditioners need servicing, make sure that the refrigerants are properly recovered and recycled instead of being vented to the atmosphere.





Reference:

Wikipedia
www.epd.gov.hk