The study found that the gas harmful to the ozone layer is declining faster than expected

International commitments to protect the ozone layer are beginning to bear fruit, as concentrations of the harmful family of gases (HCFCs) in the atmosphere have begun to fall faster than expected, according to a study published on Tuesday.

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“It is a success and makes us optimistic that climate and environmental treaties can succeed,” said Luke Western of the University of Bristol, lead author of the study published in the journal. The nature of climate change.

The Montreal Protocol, signed in 1987, is an international commitment aimed at phasing out ozone-depleting substances used in refrigeration, air conditioning, foam blowing and even in aerosols.

This made it possible to eliminate the production of chlorofluorocarbons (CFCs) but hydrochlorofluorocarbons (HCFCs) – harmful to the ozone that protects us from UV rays, but also powerful greenhouse gases – were developed to replace them. Its production and use are still in the process of being phased out.

However, the international team that published the study on Tuesday showed that the level of ozone-depleting chlorine from HCFCs had already reached its peak in 2021, five years earlier than expected. The researchers relied on measurements from a network of specialized measuring stations called AGAGE, in addition to data from the US meteorological agency NOAA.

“By implementing stringent controls and promoting alternatives that respect the ozone layer, the Protocol has succeeded in reducing emissions and levels of HCFCs in the atmosphere,” Luke Western said.

“Without the Montreal Protocol, this success would not have been possible, so it is an incredible validation of multilateral commitments to combat the loss of stratospheric ozone, with added benefits in combating climate change.”

Scientists regularly cite the protection of the ozone layer as an example of successful collective action on behalf of the environment.

According to the latest quadrennial estimate from the United Nations Environment Programme, published in early 2023, the ozone layer should “renew itself over the next four decades.”