“A huge global success.” The disappearance of ozone layer-destroying gases faster than expected

Scientists announced on Tuesday, June 11, that international efforts to protect the ozone layer have achieved a “tremendous global success” after they revealed that harmful gases in the atmosphere are declining faster than expected.

Signed in 1987, the Montreal Protocol aims to phase out ozone-depleting substances found primarily in refrigeration, air conditioning and aerosol sprays.

Since the discovery of the hole in the ozone layer in 1985, countries have agreed and amended treaties to help in its recovery, and the Montreal Protocol on Substances that Deplete the Ozone Layer, which was ratified by all member states of the United Nations, was one of the most important of these agreements, as it is widely viewed as the agreement The most successful environment ever.

A new study has found that levels of hydrochlorofluorocarbons (HCFCs), the harmful gases responsible for holes in the ozone layer, are now falling, five years from peaking in 2021.

The study's lead author, Luke Western, from the University of Bristol in the United Kingdom, told AFP: "This has been a huge global success. We see that things are moving in the right direction."

According to the report, the most harmful chlorofluorocarbons (CFCs) were to be phased out by 2010 in an attempt to protect the ozone layer, the shield that protects life on Earth from harmful levels of ultraviolet rays coming from the sun.

The HCFCs they replaced are expected to be phased out by 2040.

HCFCs contain chlorine, fluorine and carbon (just like CFCs), but they also contain a hydrogen atom, which reduces their stability and gives them a shorter lifespan.

This study, published in the journal Nature Climate Change, examined levels of these pollutants in the atmosphere using data from the Advanced Global Atmospheric Gas Experiment and the US National Atmospheric and Oceanic Administration.

Western attributed the sharp decline in hydrochlorofluorocarbons (HCFCs) to the effectiveness of the Montreal Protocol. 

“In terms of environmental policy, there is some optimism that these environmental treaties can work if they are properly enacted and properly followed,” Western said.

Both hydrochlorofluorocarbons (HCFCs) and chlorofluorocarbons (CFCs) are potent greenhouse gases, which means their reduction would also help combat global warming.

Western noted that chlorofluorocarbons (CFCs) can remain in the atmosphere for hundreds of years, while hydrochlorofluorocarbons (HCFCs) have a lifespan of about two decades.

Even after their production is discontinued, past use of these products will continue to affect ozone for years to come.

The United Nations Environment Program estimated in 2023 that it could take four decades before the ozone layer recovers to levels before the hole was first discovered in the 1980s.