Key highlights of study
- Impact of Hydrochlorofluorocarbons (HCFCs) on Earth’s energy balance and globally averaged chlorine content of ODS in troposphere has decreased since 2021, five years earlier (2026) than expected.
- HCFCs are compounds containing carbon, hydrogen, chlorine and fluorine.
- HCFC-22, most abundant HCFC, has declined significantly. Its Global Warming Potential (GWP) is thousands of times more than carbon dioxide (CO2).
- HCFC-22 is used as a refrigerant in air conditioners, cold storage, retail food refrigeration, etc.
- Minor decline were observed in HCFC-141b, second most abundant HCFC.
- HCFC-141b is used as a blowing agent in production of rigid polyurethane foams.
- India has achieved complete phase-out of HCFC-141b under ODS (Regulation and Control) Amendment Rules, 2014.
- This is in line with India’s commitment under Montreal Protocol for Substances that Deplete Ozone Layer.
Montreal Protocol
- Signed in 1987, it is a global treaty to eliminate production and use of ODS.
- Implemented under Vienna Convention (adopted in 1985).
- Kigali Amendment to Montreal Protocol was adopted in 2016 (and entered into force in 2019) to phase-down production and consumption of Hydrofluorocarbons (HFCs).
- HFCs are non-ODS alternative to CFCs and HCFCs. HFC’s GWP is thousands of times more than CO2.
Ozone and Ozone-Depleting Substances (ODS)
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