Which of the following is the chief role of Ozone Layer?

Correct option is A

The correct answer is: (a) To reduce Ultraviolet rays

The ozone layer, located in the stratosphere, acts as a protective shield by absorbing the majority of the Sun’s harmful ultraviolet (UV) radiation, particularly UV-B and UV-C rays. Without the ozone layer, these UV rays would reach the Earth's surface and cause severe damage to living organisms, including skin cancer, cataracts, and harm to plant and marine life.

Role of the Ozone Layer:

• Protects living organisms by filtering out harmful UV radiation.
• Maintains ecological balance by reducing UV-related damage to ecosystems.

Threats to the Ozone Layer:

• Chlorofluorocarbons (CFCs): Chemicals used in refrigeration and aerosols that break down ozone molecules.
• Halons and Other ODS (Ozone-Depleting Substances): Contribute to ozone depletion, creating the ozone hole.

Efforts to Protect the Ozone Layer:

• The Montreal Protocol (1987): An international treaty aimed at phasing out the production and use of ozone-depleting substances.
• Promoting the use of eco-friendly substitutes for CFCs and halons.

Additional Information:

Ozone Layer Depletion:

• Refers to the thinning of the ozone layer, especially over the polar regions, forming the "ozone hole."
• This thinning reduces the layer's ability to absorb harmful UV radiation.

Causes of Ozone Layer Depletion:

• Chlorofluorocarbons (CFCs): Found in refrigerants, aerosols, and solvents. When released, CFCs break down in the stratosphere, releasing chlorine atoms that destroy ozone molecules.
• Halons: Used in fire extinguishers; release bromine, which is even more destructive to ozone than chlorine.
• Nitrous Oxide: Emitted from agricultural fertilizers and industrial processes, reacts with ozone in the stratosphere.
• Natural Factors: Volcanic eruptions and solar activity can contribute to temporary changes in ozone concentration.

Impact of Ozone Depletion:

• Increased UV Radiation:
  • Leads to higher incidence of skin cancers, cataracts, and sunburns.
  • Damages DNA in living organisms.
• Climate Effects: Changes atmospheric circulation patterns, affecting weather and climate systems.
• Marine Ecosystems: UV rays harm phytoplankton, which are the foundation of oceanic food webs.
• Agriculture: UV sensitivity of crops like soybeans and wheat can lead to reduced yields.

International Efforts to Reduce Ozone Depletion:

• Montreal Protocol (1987):

  • A landmark international treaty to phase out the production and use of ozone-depleting substances like CFCs and halons.
  • Highly successful, with significant reductions in harmful emissions.

• Kigali Amendment (2016):

  • Extended the Montreal Protocol to include the phasedown of hydrofluorocarbons (HFCs), which are potent greenhouse gases but not direct ozone depleters.