The second layer of the Earth's atmosphere is the ozone layer. It has a job of absorbing bits of radiation from the sun that hits the Earth. We need some of the sun's radiation to live, but too much of it can damage living things. 98 percent of ultraviolet radiation, or UV light, is absorbed by the ozone layer. UV light can penetrate organisms' protective layers, like skin, damaging DNA molecules in plants and animals. UVB and UVA, two major types of UV light, cause cancer.

Our protective layer, the ozone, is getting thinner. It means that most of the UV light is not absorbed and reaches the Earth. The reason why the ozone is thinning is due to chemicals like chlorofluorocarbons (CFCs). CFC is a molecule that contains elements carbon, chlorine, and fluorine. They can be found everywhere, but are mostly in refrigerants and plastic products. CFCs are often used because they are inexpensive, they don't catch fire easily, and they don't usually poison living things. Once the CFCs are in the stratosphere, they would start eating away at the ozone layer. CFCs in the air makes it very difficult for ozone to reform once it's broken apart, thus the ozone layer getting thinner and thinner all the time.

Realizing this, the world has made agreements in preserving the ozone layer. The most successful environment protection agreement is the Montreal Protocol. 197 countries have ratified the Montreal Protocol making it the first international environmental treaty to achieve complete ratification. The Montreal Protocol is an international agreement made in 1987, which was designed to stop the production and use of ozone depleting substances as well as to reduce their concentration in the atmosphere to help protect the Earth?s ozone layer. The Montreal Protocol targets 96 ozone-depleting chemicals in thousands of applications across more than 240 industrial sectors. A timetable has been set out for the phase out of ozone depleting substances in which are differentiated between developed and developing countries. The timetable has been reviewed regularly, with phase out dates accelerated in accordance with scientific understanding and technological advances.

The ozone layer is slowly recovering. Below are achievements that Indonesia has made concerning ozone layer protection program:

1.  Relevant government agencies (Ministries of Environment, Health, Trade, Industry, Agriculture, etc) released various regulations in compliance with the Environmental Law 23/1997 and the Montreal Protocol to control and prohibit the import/use of certain ODS in cosmetics, agriculture, households, shipping, etc.

2. As of 2008, Indonesia has already banned the import of Chlorofluorocarbons (CFCs).

3.  As of 2010, Indonesia is successfully in compliance with the Montreal Protocol control schedule for CFCs, Carbon Tetrachloride (CTC) and Halons.

4.   As of 2012, Indonesia has been implementing various activities to phase-out the consumption of Hydrochlorofluorocarbons (HCFCs) in coordination with Multilateral Fund (MLF) Secretariat, Implementing Agencies (UNDP, World Bank, UNIDO and UNEP), the Government of Australia, private sector and experts.

 

I'm a bit late, but. Happy International Day for the Preservation of the Ozone Layer! Fun fact, it celebrates the anniversary of the day the Montreal Protocol came into effect.

Source

https://www.nationalgeographic.org/encyclopedia/ozone-layer/

http://www.environment.gov.au/protection/ozone/montreal-protocol

http://www.id.undp.org/content/dam/indonesia/Project%20Docs/hpmp/HPMP%20-IDN%20MP%20OLP%20v%2002.pdf