India Observes 27th Global Ozone Day

Global Ozone Day

• In 1994, the UN General Assembly (UNGA) declared the 16th September as International Day for the Preservation of the Ozone Layer. 
• The day marks the signing of the Montreal Protocol on Substances that deplete the Ozone Layer, in 1987.
  • The Montreal Protocol seeks to phase out Ozone Depleting Substances (ODS) to preserve the ozone layer and prevent further damage to it.

Ozone

• Ozone is a molecule that contains three oxygen atoms (O₃). 
  • It is a pale blue gas with a pungent (chlorine-like) smell.
• The ozone layer is the common term for the high concentration of ozone that is found in the stratosphere around 86 to 92 km above the earth’s surface. 
  • It was first discovered by the French physicists Charles Fabry and Henri Buisson in 1913.
  • Density of Ozone is measured in the Dobson (Db) Unit.
  • Ozone Layer in the atmosphere is thicker over the poles than over the equator.
• In the troposphere, it is considered as a pollutant causing eye irritation and respiratory hardship.

How is Ozone Created?

• When the sun’s rays (Ultraviolet rays) strike oxygen (O₂) molecules, it splits oxygen molecules into single atoms.
• The single atom Oxygen reacts with another oxygen molecule to form Ozone.

Source: Canada Government

Significance of Ozone

• It covers the entire planet and protects life on earth by absorbing harmful ultraviolet-B (UV-B) radiation from the sun.
• Impact on Plants
  • Plants cannot live and grow in heavy ultraviolet radiation, nor can the planktons that serve as food for most of the ocean life.
• Health impact of UV-B rays
  • With a weakening of the Ozone Layer shield, humans would be more susceptible to skin cancer, cataracts and impaired immune systems.
• Without it, life may have been impossible on earth due to harmful UV-B rays.

Ozone Depleting Substances

• Major Ozone Depleting substances are
  • Chlorofluorocarbons (CFCs) and 
  • Halons
• The major sources of Ozone Depleting Substances (ODSs) are
  • Manufactured halocarbon refrigerants, 
  • Solvents, 
  • Propellants, and 
  • Foam- blowing agents

Source: NOAA

Mechanism of Ozone Depletion: Role of Polar Stratospheric Clouds

• The largest Ozone hole appears over Antarctica at the onset of summer.
• Polar Vortex concentrates ODSs around poles.
• During winters, the Polar Stratospheric Clouds (PSCs) are formed.
  • They provide the catalytic site for reaction between Ozone molecules and CFCs or Halons.
  • CFCs and Halons are non degrading long lived pollutants and create a chain reaction which keeps on depleting ozone.
• Suddenly in winter, when Polar Stratospheric Clouds melt the hole suddenly appears.

Source: PublicHealthNotes

India Cooling Action Plan (ICAP)

• The Plan is the first of its kind in the world to be developed by the MoEF&CC.
  • It addresses cooling requirements across sectors. 
  • It also lists out actions which can help reduce the cooling demand through synergies in actions for securing both environmental and socio-economic benefits. 
  • The ICAP aims to reduce both direct and indirect emissions.

Montreal Protocol

• Montreal Protocol is a multilateral environmental agreement.
• It regulates the production and consumption of ozone-depleting substances (ODS). 
• It was adopted on September 15, 1987. 
• It is one of the most successful environmental agreements across the world.

Kigali Amendment

• The Parties to the Montreal Protocol reached agreement at their 28th Meeting of the Parties on 15 October 2016 in Kigali, Rwanda.
  • Aim: To phase-down hydrofluorocarbons (HFCs). 
  • Note: Although Montreal Protocol is for ODS, HFCs are not ODS.
    • HFCs are Green-House Gases but HFCs were invented to phase out ODS.
  • Hence, taking moral responsibility to not create another monster to curb one problem,the Kigali amendment was introduced.
• Countries agreed to add HFCs to the list of controlled substances, and approved a timeline for their gradual reduction by 80-85 percent by the late 2040s.