The ozone layer is the shield that protects life on Earth from harmful levels of ultraviolet rays from the Sun, and since the Montreal protocol was agreed in 1987, progress has now been shown to be ahead of target.
International efforts to protect the ozone layer have been a “huge global success”, scientists have said, after revealing that damaging gases in the atmosphere were declining faster than expected.
The Montreal protocol, signed in 1987, aimed to phase out ozone-depleting substances found primarily in refrigeration, air conditioning and aerosol sprays. According to a study published this week in Nature Climate Change, the good news is that atmospheric levels of hydrochlorofluorocarbons (HCFCs), harmful gases responsible for holes in the ozone layer, peaked in 2021 - five years ahead of projections.
“This has been a huge global success. We’re seeing that things are going in the right direction,” the study’s lead author, Luke Western from the University of Bristol, said.
Western attributed the steep decline in HCFCs to the efficacy of the Montreal protocol, as well as tighter national regulations and a shift by industry in anticipation of the coming ban of these pollutants. “In terms of environmental policy, there is some optimism that these environmental treaties can work if properly enacted and properly followed,” he said.
Both CFCs (which were phased out by 2010) and HCFCs are also powerful greenhouse gases, meaning their decline also aids in the fight against global heating.
The hole in the Earth’s ozone layer, once the most feared environmental peril facing humanity, is set to be completely healed over most of the world within two decades following decisive action by governments to phase out ozone-depleting substances, according to a UN assessment in January 2023. The loss of the ozone layer, which risked exposing people to harmful ultraviolet rays from the sun, is on track to be completely recovered by 2040 across the world, aside from the polar regions, according to the report. The poles will take a little longer - the ozone layer will fully bounce back by 2045 over the Arctic and by 2066 over the Antarctic.