Decline in greenhouse gases that destroy the ozone layer

June 11 () –

New study reveals significant progress in campaign to reduce atmospheric levels of chemicals that They destroy the Earth’s protective ozone layer.

Published in Nature Climate Change by an international team of scientists, the research confirms the success of historical regulations that limited its production and use.

Led by the University of Bristol, the study shows for the first time a notable decline in atmospheric levels of potent ozone-depleting substances (ODS), called hydrochlorofluorocarbons (HCFCs). These HCFCs are also harmful greenhouse gases (GHGs), so its reduction should also reduce global warming.

The Montreal Protocol was agreed internationally in 1987 to introduce controls on the production and use of ODS, once widely used in the manufacture of hundreds of products, including coolers, aerosols, foams and packaging. HCFCs were developed as replacements for chlorofluorocarbons (CFCs). Although the production of CFCs has been banned globally since 2010, the production and use of HCFCs is still being phased out globally, with phase-out expected to be completed in 2040. They will be replaced by hydrofluorocarbons (HFCs) and other compounds that They do not damage the ozone layer.

“The results are very encouraging. They underline the great importance of establishing and complying with international protocols,” says it’s a statement lead author Luke Western, from the University of Bristol’s School of Chemistry. “Without the Montreal Protocol, this success would not have been possible. It is therefore a resounding endorsement of multilateral commitments to combat stratospheric ozone depletion, with additional benefits to address human-induced climate change.”

The international study shows that the total amount of ozone-depleting chlorine contained in all HCFCs together peaked in 2021. Since these compounds are also potent greenhouse gases, their contribution to climate change also peaked. peak that year. This peak occurred five years earlier than predicted in the last ozone assessment report published in 2022. Although the reduction between 2021 and 2023 was less than 1%, continues to show that HCFC emissions are heading in the right direction.

The results are based on high-precision measurements carried out at atmospheric observatories distributed around the world, using data from the Advanced Global Atmospheric Gases Experiment (AGAGE) and the National Oceanic and Atmospheric Administration (NOAA) of the United States.