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Climate crisis: Oceans may emit more ozone-depleting gases

  • Posted By
    10Pointer
  • Categories
    Environment
  • Published
    19th Mar, 2021

Context

Recent research has found that oceans would emit more CFC-11 by 2075 than they absorb, and emit detectable amounts of the chemical by 2130.

What are the findings?

  • Solubility: CFCs are more soluble when sea surface temperatures are low.
  • Release of CFC: Oceans may start releasing chlorofluorocarbons (CFC), a class of ozone-depleting chemicals, at a faster rate due to rising global temperatures.
    • Changes in oceanic levels of this gas have been shown to affect changes in its atmospheric concentrations.
    • The oceans, which are a vast repository for gases, would emit more CFC-11 by 2075 than they absorb.
    • They would emit detectable amounts of the chemical by 2130.
    • The shift will occur 10 years earlier due to climate change.
    • The emissions of CFC-11 from the ocean will effectively extend the chemical’s average residence time, causing it to linger five years longer in the atmosphere than it otherwise would.
    • By 2145, the ocean would emit CFC-11 in amounts that would be detectable by current monitoring standards.
    • If the planet warms by five degrees Celsius by 2100, the ocean will become a net emitter of CFC-11 by 2065 and release detectable levels by 2140.

What are CFCs?

  • Chlorofluorocarbons (CFCs) are fully or partly halogenated paraffin hydrocarbons.
  • They contain only carbon (C), hydrogen (H), chlorine (Cl), and fluorine (F).
  • They are produced as volatile derivatives of methane, ethane, and propane.
  • Uses: CFCs have been widely used as refrigerants, propellants (in aerosol applications), and solvents.
  • Ozone depletion: Because CFCs contribute to ozone depletion in the upper atmosphere, they are being replaced with other products such as hydrofluorocarbons (HFCs)[1] including R-410A and R-134a.[

Restrictions on CFCs

  • CFCs are stringently controlled after 196 countries in the United Nations came together under the 1987 Montreal Protocol to protect the ozone layer.

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