Ozone hole gradually closing, United Nations report says

Rodiano Bonacci
Novembre 9, 2018

The Assessment, which is meant to add to the scientific basis for decisions made by the Parties to the Montreal Protocol, also presents updated scenarios for hastening ozone recovery through: Complete elimination of controlled and uncontrolled emissions of substances such as carbon tetrachloride and dichloromethane, Bank recapture and destruction of chlorofluorocarbons (CFCs), halons, and hydrochlorofluorocarbons (HCFCs) and Elimination of HCFC and methyl bromide production, as well as the Mitigation of nitrous oxide emissions.

"At projected rates, Northern Hemisphere and mid-latitude ozone is scheduled to heal completely by the 2030s followed by the Southern Hemisphere in the 2050s and polar regions by 2060".

The ozone layer that shields life from cancer-causing solar rays is recovering at a rate of one to three percent per decade, reversing years of risky depletion caused by the release of harmful chemicals, a United Nations study said on Monday.

It shows that the concentration of ozone-depleting substances continues to decrease, leading to an improvement in the layer since the previous assessment carried out in 2014.

At its worst, during the late 1990s, about 10% of the upper Earth's ozone layer was depleted, according to Newman. This year, the ozone hole over the South Pole totalled almost 25 million square kilometers - 16% smaller than the 2006 peak. That's roughly 16% smaller than the biggest hole ever recorded, which was 11.4 million square miles in 2006. Newman added that if we hadn't made these changes, two-thirds of the ozone layer would have been destroyed by 2065.

He claims that we are only in the phase in which the recovery has just begun, and some other ozone measurements have not increased yet.

On its own, the ozone hole has slightly shielded Antarctica from the much larger effects of global warming - it has heated up but not as much as it likely would without ozone depletion, said Ross Salawitch, a University of Maryland atmospheric scientist who co-authored the report.

Another problem is that new technology has found an increase in emissions of a banned CFC out of East Asia, the report noted.

This agreement is now projected to reduce future global average warming in 2100 due to hydrofluorocarbons (HFCs) from a baseline of 0.3-0.5-degrees C to less than 0.1-degree C. Cross your fingers all goes as planned.

The replacements that are now being used to cool cars and refrigerators have to be replaced themselves with some chemicals that will not be worsening the global warming. It's all thanks to the Montreal Protocol, a treaty created to stop the spread of ozone-depleting substances (ODS). Newman said we need to wait until 2060, and let our grandchildren do the celebrating.

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