Ozone Hole, filling up now

Ozone Hole, filling up now

News: The ozone ‘hole’, once considered to be the gravest danger to planetary life, is now expected to be completely repaired by 2066, a scientific assessment has suggested. 
• This is stated in an UN-backed scientific team report titled ‘Scientific Assessment of Ozone Depletion 2022’.

Key findings:
• The ozone layer is predicted to return to 1980 levels over Antarctica by 2066, 2045 for the Arctic, and 2040 for the remainder of the planet.
• The ozone hole has been steadily improving since 2000, thanks to the Montreal Protocol’s (1987) effective implementation.
• The Montreal Protocol mandates countries to phase out production of all main ozone depleting substances (ODSs).
• The Kigali Amendment (2016) to the Montreal Protocol aims to phase down 80-90% of the hydrofluorocarbons (HFCs) currently in use by 2050. HFCs have replaced chlorofluorocarbons (CFCs) in industrial use and the amendment seeks to prevent additional 0.3 to 0.5 degree Celsius of global warming by the end of the century.
• HFCs do not cause much ozone layer damage, which is why they were not originally prohibited, but they are extremely powerful greenhouse gases (GHGs).
• Nearly 99% of the Montreal Protocol-banned substances have now been phased out of usage, resulting in a slow but steady rebuilding of the ozone layer.
• The eradication of ODSs has a significant climate change co-benefit because these compounds are also potent GHGs, expected to prevent 0.5 to 1 degree Celsius of warming by 2050.

Can this success story help with reducing Global warming?
• The success of the Montreal Protocol in closing the ozone hole is widely mentioned as a model for climate action.
• However, the parallels between the eradication of ODSs and the reduction of GHGs are limited because the usage of ODSs (though widespread) was limited to a few specific industries and their replacements were readily available. With some incentives, these sectors have recovered from the initial disruption and are thriving again.
• The case of fossil fuels is very different. Emission of carbon dioxide is inextricably linked to the harnessing of energy. Almost every economic activity leads to carbon dioxide emissions. Even the so-called renewable energies, like solar or wind, have considerable carbon footprints right now, because their manufacturing, transport, and operation involves the use of fossil fuels.
• The emissions of methane, the other major greenhouse gas, comes mainly from agricultural practices and livestock. The impact of restraining greenhouse gas emissions is not limited to a few industries or economic sectors, but affects the entire economy, and also has implications for the quality of life, human lifestyles and habits and behaviours. 

Conclusion:
• Climate change, no doubt, is a far more difficult and complex problem than dealing with ozone depletion. 
Key Term you must know from Prelims perspective – Dobson Unit 
• The Dobson Unit is the most common unit for measuring ozone concentration.