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Question

Difficulty: Very hardClimate Change, Global Warming and Ozone Layer Depletion

Match List-I (Atmospheric Pollutants / Synthetic Compounds) with List-II (Regulatory Frameworks and Environmental Characteristics) and select the correct matching pairs.

  • Perfluorocarbons (PFCs)Extremely persistent synthetic greenhouse gases with atmospheric lifetimes up to thousands of years, emitted primarily during primary aluminum smelting
  • Stratospheric HalonsBromine-containing compounds possessing significantly higher Ozone Depleting Potential (ODP) per molecule than standard chlorofluorocarbons
  • Hydrofluorocarbons (HFCs)Phased down globally under the Kigali Amendment due to high Global Warming Potential (GWP) despite possessing zero Ozone Depleting Potential (ODP)
  • Nitrogen Trifluoride (NF3NF_3)Added to the official basket of targeted greenhouse gases under the Kyoto Protocol during its Second Commitment Period (Doha Amendment)

Answer

Perfluorocarbons (PFCs) match with extremely persistent synthetic GHGs emitted primarily during primary aluminum smelting. Stratospheric Halons match with bromine-containing compounds possessing significantly higher ODP per molecule than standard CFCs. Hydrofluorocarbons (HFCs) match with phase-down under the Kigali Amendment due to high GWP despite zero ODP. Nitrogen Trifluoride (NF3NF_3) matches with addition to the Kyoto Protocol basket under the Doha Amendment.
Perfluorocarbons (PFCs) are extremely long-lived synthetic greenhouse gases originating from aluminum smelting. Stratospheric Halons contain bromine, which exhibits much higher Ozone Depleting Potential per molecule than chlorine in CFCs. Hydrofluorocarbons (HFCs) have zero Ozone Depleting Potential but high Global Warming Potential, leading to their regulation under the Kigali Amendment. Nitrogen Trifluoride (NF3NF_3) was added to the Kyoto Protocol greenhouse gas list during the Doha Amendment.

Step-by-Step Solution

1
Analyze the industrial sources and chemical persistence of Perfluorocarbons (PFCs).
PFCs (CF4CF_4, C2F6C_2F_6) are generated as inadvertent byproducts during aluminum smelting (anode effect) and microelectronics etching, characterized by extreme atmospheric lifetimes (up to 50,000 years).
Links PFCs to aluminum smelting emissions and extreme atmospheric longevity.
2
Evaluate the atmospheric ozone destruction potential of Halons.
Halons carry bromine atoms (BrBr), which participate in catalytic ozone destruction cycles that are substantially more destructive per atom than the chlorine cycles of CFCs.
Establishes why Halons exhibit higher ODP values compared to standard CFCs.
3
Examine the international legal regime covering Hydrofluorocarbons (HFCs).
While HFCs do not harm the ozone layer (zero ODP), they are potent greenhouse gases. The 2016 Kigali Amendment legally amended the Montreal Protocol to include HFC phase-down schedules.
Connects HFCs with zero ODP and the Kigali Amendment phase-down framework.
4
Trace the history of greenhouse gas listings under the Kyoto Protocol for Nitrogen Trifluoride (NF3NF_3).
The original 1997 Kyoto Protocol covered six gases (CO2CO_2, CH4CH_4, N2ON_2O, HFCs, PFCs, SF6SF_6). Nitrogen Trifluoride (NF3NF_3) was added as the seventh gas under the 2012 Doha Amendment for the second commitment period (2013–2020).
Pairs NF3NF_3 with the Doha Amendment expansion of the Kyoto Protocol GHG basket.

Key Concept

Chemical mechanisms of ozone depleting substances, greenhouse gas profiles, and global climate governance treaties
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Topics

Climate Change, Global Warming and Ozone Layer Depletion