UPPSC 2022 Prelims GS Paper-I · Question 137 of 150

Correct — A, September 16. The day is formally the International Day for the Preservation of the Ozone Layer, commonly called World Ozone Day, and it falls on 16 September every year. The date is not arbitrary: it marks the signing of the Montreal Protocol on Substances that Deplete the Ozone Layer on 16 September 1987. The United Nations General Assembly designated the observance in 1994, and it has been kept on that date since. The anchor to remember is therefore the treaty, not the day — once you know the Montreal Protocol was signed on 16 September 1987, the observance follows automatically, and the same trick works for several other environmental days that commemorate the adoption of a convention. The other three dates in this question are all real observances, but none of them has anything to do with the ozone layer.

• (b)January 30 — 30 January is Martyrs' Day in India, marking the assassination of Mahatma Gandhi in 1948. It is a national day of remembrance, entirely unconnected with the ozone layer or with any environmental treaty.
• (c)October 2 — 2 October is Gandhi Jayanti, Mahatma Gandhi's birth anniversary, observed internationally as the International Day of Non-Violence. Placing two Gandhi dates among the options is the setter's way of pulling attention away from the environmental calendar altogether.
• (d)April 29 — 29 April is International Dance Day. Like the other two distractors it is a genuine observance, but it belongs to the cultural calendar and has no link to ozone depletion or to the Montreal regime.

The ozone layer lies in the stratosphere, roughly 15 to 35 kilometres up, and absorbs essentially all incoming UV-C and most UV-B radiation. Its vulnerability to chlorofluorocarbons was established by Mario Molina and F. Sherwood Rowland in 1974, work for which they shared the 1995 Nobel Prize in Chemistry with Paul Crutzen; the Antarctic ozone hole was reported by the British Antarctic Survey in 1985. The international response came in two steps — the Vienna Convention for the Protection of the Ozone Layer in 1985, a framework agreement, and the Montreal Protocol of 16 September 1987, which put binding phase-out schedules on the substances themselves. The Protocol has since been amended repeatedly, most notably by the Kigali Amendment of 2016, which brings in hydrofluorocarbons — chemicals that do not deplete ozone at all but are potent greenhouse gases. World Ozone Day, designated by the UN General Assembly in 1994, commemorates the Protocol's signing.

Observance-date questions are pure recall, so the efficient strategy is to attach each date to the event it commemorates rather than to memorise a bare calendar. 16 September is the Montreal Protocol's signing; 5 June is World Environment Day, from the opening of the Stockholm Conference in 1972; 22 May is the International Day for Biological Diversity, marking the adoption of the Convention on Biological Diversity text at Nairobi in 1992; 3 March is World Wildlife Day, marking the adoption of CITES in 1973; 22 March is World Water Day; 5 December is World Soil Day; 29 July is Global Tiger Day, from the St Petersburg Tiger Summit of 2010. Attaching the anchor also protects against the commonest trap, which is a plausible-looking near date — several environmental days have shifted at some point, and the UPPSC papers frequently print a wrong date deliberately and ask which pair fails. Keep the ozone regime firmly separate from the climate regime: the Vienna Convention and Montreal Protocol are about ozone-depleting substances, while the UNFCCC, Kyoto Protocol and Paris Agreement are about greenhouse gases. Confusing the two is the single most common error in this whole area.

• World Ozone Day — formally the International Day for the Preservation of the Ozone Layer — is observed on 16 September, marking the signing of the Montreal Protocol on 16 September 1987; the UN General Assembly designated the observance in 1994.
• The distractor dates are all genuine but unrelated: 30 January is Martyrs' Day in India, 2 October is Gandhi Jayanti and the International Day of Non-Violence, and 29 April is International Dance Day.
• The ozone layer sits in the stratosphere at roughly 15 to 35 km and absorbs essentially all UV-C and most UV-B radiation.
• The Vienna Convention (1985) is the framework agreement; the Montreal Protocol (1987) carries the binding phase-out schedules; the Kigali Amendment (2016) adds hydrofluorocarbons, which do not deplete ozone but are potent greenhouse gases.
• The CFC-ozone link was established by Molina and Rowland in 1974 (Nobel Prize in Chemistry 1995, shared with Paul Crutzen); the Antarctic ozone hole was reported by the British Antarctic Survey in 1985.

• Confusing the ozone regime (Vienna, Montreal, Kigali) with the climate regime (UNFCCC, Kyoto, Paris)
• Assuming hydrofluorocarbons deplete ozone; they do not, but they are strong greenhouse gases, which is why Kigali covers them
• Learning observance dates as a bare list rather than through the event each commemorates, which is what makes near-miss dates in options hard to reject

UPPSC asks environmental days constantly — either as a one-line 'on which date' as here, or as a match list, or as a 'which pair is NOT correctly matched' with one date deliberately altered. The ozone date in particular has come up in more than one year. UPSC seldom asks the date itself and instead tests the instrument behind it, most often by asking which agreement deals with phasing out ozone-depleting substances.

• practice — not a real PYQ

  World Ozone Day is observed on 16 September because that date marks the

  • (a)Discovery of the Antarctic ozone hole
  • (b)Signing of the Montreal Protocol
  • (c)Adoption of the Vienna Convention
  • (d)Entry into force of the Kigali Amendment

  Answer(b) Signing of the Montreal Protocol — the treaty was signed on 16 September 1987, and the UN General Assembly designated the observance in 1994 to commemorate it. The Antarctic hole was reported in 1985, the same year the Vienna Convention was adopted.

• practice — not a real PYQ

  Which one of the following pairs is NOT correctly matched?

  • (a)World Environment Day — 5 June
  • (b)International Day for Biological Diversity — 22 May
  • (c)World Soil Day — 5 December
  • (d)World Ozone Day — 16 December

  Answer(d) World Ozone Day — 16 December. The correct date is 16 September; the other three pairs are correct. Swapping the month while keeping the day is the standard way these options are made to look right.