Scientific Assessment of the Ozone Layer Depletion: 2022
Recently, the United Nations-backed Scientific Assessment Panel Report (Scientific Assessment of Ozone Depletion: 2022) has been released for Montreal on ozone depleting substances.
Published every four years, the report confirms the phase-out of about 99% of banned ozone-depleting substances.
Key findings of repot-
- According to the latest report, the Montreal Protocol has been successful in protecting the ozone layer, which has led to a significant recovery of the ozone layer in the upper stratosphere and has reduced the human exposure to harmful ultraviolet (UV) radiation from the Sun.
- The report states that if the current crackdown policies continue, the ozone layer is expected to regain the ozone level of the 1980s (before the ozone hole appeared) over the Antarctic by about 2066, over the Arctic by 2045, and over the rest of the world by 2040.
- The 2016 Kigali Amendment to the Montreal Protocol requires a phase-out of the production and consumption of hydrofluorocarbons (HFCs).
- HFCs do not directly destroy ozone, but they are potent climate change gases. The report states that compliance with the Kigali Amendment could avoid 0.3–0.5°C of warming by the year 2100.
- For the first time, the Scientific Assessment Panel has examined the potential effects on ozone by artificially introducing aerosols into the stratosphere.
- This technique, known as stratospheric aerosol injection (SAI), is a geo-engineering technique.
- The panel warned that the SAI’s unintended consequences could also affect “stratospheric temperature, circulation, and the rate of ozone production and destruction”.
Most atmospheric ozone is concentrated in a layer in the stratosphere, about 9 to 18 miles (15 to 30 km) above Earth’s surface, and reduces the amount of harmful ultraviolet radiation that reaches Earth from the Sun.
Ozone-depleting potential (ODP)
Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), dibromofluorocarbons (HBFCs), halons, methyl bromide, carbon tetrachloride and methyl chloroform.
The Vienna Convention for the Protection of the Ozone Layer was adopted and signed by 28 countries on 22 March 1985. In September 1987, it drafted the Montreal Protocol on Substances that Deplete the Ozone Layer.
Montreal Protocol- 1987
- The Montreal Protocol is an international environmental treaty for the protection of the ozone layer by phasing out the production and consumption of man-made chemicals known as ozone depleting substances (ODPs).
- The stratospheric ozone layer protects humans and the environment from harmful levels of ultraviolet radiation from the Sun.
- The Kigali Amendment to the Montreal Protocol was adopted during the 28th Meeting of the Parties to the Montreal Protocol held in October 2016 in Kigali, Rwanda.
- Under the Kigali Amendment; Parties to the Montreal Protocol will reduce the production and consumption of hydrofluorocarbons, commonly known as HFCs.
- Hydrofluorocarbons (HFCs) were introduced as non-ozone depleting alternatives to chlorofluorocarbons.
- HFC does not harm the stratospheric ozone layer but it contributes more to global warming, which has an adverse effect on the climate.
- Therefore, the Kigali Agreement has been signed to phase out the use of hydrofluorocarbons.
India – Montreal Protocol
India became a party to the Montreal Protocol on Substances that Deplete the Ozone Layer on June 19, 1992 and since then India has ratified amendments to the Montreal Protocol.
Source – The Hindu