The ozone layer is sunscreen. It absorbs UV emissions. But the rate at which the Ozone layer is getting destroyed is much faster than the rate at which it is formed. The main culprits are gaseous chlorine and bromine.
The ozone layer is found in the lower portion of the Stratosphere i.e. 12 to 19 miles above the earth. It is natural gas with the chemical symbol O3 i.e it is an allotrope of oxygen. One of the main sources effecting the ozone layer is chlorofluorocarbons (CFCs). They are widely used in refrigerators, plastic manufacturing, ACs, aerosol sprays etc. A single chlorine atom destroys thousands of Ozone molecules.
Another source is Nitrogen oxide which is mainly from industrial emissions and agricultural fertilizers. Bromine is more dangerous than chlorine. Each bromine atom destructs a hundred times more destruction than a chlorine atom does. Halons, Carbon tetrachlorides, and Hydro Fluorocarbons are also sources of Ozone destruction.
Ozone layer depletion is more evident over the Antarctic and Arctic regions. Every year a hole as bigger as the USA forms over Antarctica. As a result of the destruction of the Ozone layer humans and animals are exposed to ultra violet radiations , which are causing different types of cancers and other serious health problems. Ultraviolet rays effect plant life by causing damage to photosynthesis process. They also effect marine life.
Then how to protect Ozone layer ?
some of the steps are,
1) Avoid using dangerous gases like CFCs, nitrous oxide etc.
2) Minimize the usage of cars. Use more public transport.
3) Alternative, eco friendly products and innovations to be encouraged.
They can tolerate water which is having 100 times more salt content when compared to normal trees.
They require high solar radiation. They can absorb fresh water from saline water.
Around 118 countries have Mangroves spanning in 1,38,000 sq.kms.
There are many uses of Mangroves. They prevent coastal soil erosion. They protect coastal lands from tsunami, floods. They support natural flora and wild life. They play an important role in sustainable revenue generation including eco-tourism, sport fishing etc.
They reduce wave height upto 66 % during storm events. It is very crucial to protect Mangroves for survival of Earth.