Context:
World Ozone Day celebrated recently.
World Ozone Day:
- Celebrated annually on September 16, as designedby United Nations General Assembly.
- India’s has been celebrating the day since 1995.
- 2024 Theme – “Montreal Protocol: Advancing Climate Actions”.
Montreal Protocol:
- An international environmental treaty for phasing out the production and consumption of Ozone Depleting Substances (ODS).
- Adopted in 1987.
- 1st United Nations treaty to be ratified by every country
- Implemented under the Vienna Convention.
Ozone (O3):
- A reactive gas made up of 3 oxygen atoms (O3).
- Types –
- Stratospheric Ozone – Found in the Earth’s stratosphere (15-30 km above the surface), produced naturally by the interaction of solar UV light with molecular oxygen (O2).
- Tropospheric Ozone – Found at ground level, primarily produced by photochemical reactions involving volatile organic compounds (VOCs) and nitrogen oxides (NOx).
- Dobson Unit (DU) – The unit used to measure the amount of ozone in a column of air from the Earth’s surface to the top of the atmosphere. The average total ozone concentration is around 300 DU.
- Importance of Ozone –
- Ozone layer in the stratosphere protects Earth from harmful ultraviolet (UV) radiation from the Sun.
- Reduces the risk of skin cancer, cataracts, and other UV-induced health issues; also protects ecosystems.
- Ozone Hole – Refers to regions with significantly reduced ozone concentration, particularly over Antarctica.
- Mainly caused by human-made chemicals like chlorofluorocarbons (CFCs) and halons.
- Depletion is exacerbated by cold stratospheric temperatures, leading to the formation of polar stratospheric clouds that facilitate ozone-destroying reactions.
Read more about: Montreal Protocol
Source: Down to Earth
Previous Year Question
Which one of the following is associated with the issue of control and phasing out of the use of ozone-depleting substances?
[UPSC Civil Services Exam – 2015 Prelims]
(a) Bretton Woods Conference
(b) Montreal Protocol
(c) Kyoto Protocol
(d) Nagoya Protocol
Answer: (b)
Explanation:
The Montreal Protocol provides a set of practical, actionable tasks to phase out ozone- depleting substances. Therefore, option (b) is the correct answer.