What is the ozone layer and why is it important?

The ozone layer is a layer present in the atmosphere, and it prevents excessive UV radiations from entering into Earth. In a sense, it is what protects the earth and living organisms from the harmful radiations of the sun. if those UV radiations enter the Earth, then we, humans will be exposed to great danger,

the most commonly known effect is skin cancer. Other effects are eye damage, damage to the immune system, acceleration of the aging process of your skin and it can even lead to hampering of lung functions.

The UV radiations also have adverse effects on other life forms and on the environment itself, environmental consequences affect humans too.

While being aware of the ozone layer?s depletion consequences, some of us miss the fact that humans themselves and the manufactured chemicals we use and make are the cause of it. Ozone-depleting substances include halocarbon refrigerants, methyl bromide used in pesticides, halons used in fire extinguishers and methyl chloroform used in making industrial solvents. 

A treaty made to phase down the depletion of the stratospheric ozone layer, the layer that protects the earth from the sun, is the Montreal Protocol on Substances that Deplete the Ozone Layer. It has proven itself to be one of the most successful treaties for binding countries (197 states and the EU) together to work towards one goal, which is it protect the ozone layer from chemicals and to stop its depletion. It has successfully curbed the 98% production of chlorofluorocarbons and other ODSs and significantly contributed to the repair of the ozone hole, after starting an international ban on damaging chemicals. The ozone hole has shrunk by 4 million square km overall since the year 2000. Additionally, researchers analyzed that the rate of ozone less decreased by 20 percent after using MLS data gathered every winter between 2005 and 2016. This is all due to the efforts of the Montreal protocol.

The most recent amendment is the Kigali Amendment to the Montreal protocol, which calls for a phase down in the production of hydrofluorocarbons, an ozone-depleting chemical, worldwide. With the contribution of the US, this agreed phase-out of HFCs will start in January 1st, 2019, the technology for alternatives to fluorocarbons is available but substitution will take some time which will offer more job opportunities for Americans. 

This amendment divided the signatory parties into 3 groups, 

• the first group includes the United States, United Kingdom and European Union countries which are rich and developed economies, who will start to phase down HFCs by 2019 and reduce it to 15% of 2012 levels by 2036.
• the second group consists of emerging economies such as China, Brazil as well as some African countries who will start to phase down by 2024 and reduce it to 20% of 2021 levels by 2045.
• the third group consists of developing economies and some of the hottest climates countries like India, Pakistan, Iran, Saudi Arabia, who will start phasing down HFCs by 2028 and reduce it to 15% of 2024-2026 levels till 2047.

It is a very significant amendment as it would prevent the emission of HFCs equivalent to 70 billion tons of CO2.