/ 13 January 2023

Ozone layer’s recovery shows climate change can be reversed


The Earth’s ozone layer shows signs of recovery after the global phasing out of ozone-depleting gases such as chlorofluorocarbons and hydrochlorofluorocarbons found in refrigeration, aerosols and air conditioners. 

This is according to a United Nations report presented at the American Meteorological Society’s 103rd annual meeting on Monday.

The use of these gases in everyday items created a continent-sized hole in the ozone layer above Antarctica.

“The impact the Montreal Protocol has had on climate change mitigation cannot be overstressed,” Meg Seki, executive secretary of the United Nations Environment Programme’s (UNEP) ozone secretariat, said in a press release. 

It was in 1985 when scientists first identified a hole in the ozone layer, which filters ultraviolet rays from the sun. Countries signed the Montreal Protocol in 1987 to phase out gases including chlorofluorocarbons.

The report points out how efforts to protect and restore the ozone layer contribute to the 2015 Paris climate agreement’s goal of keeping global heating this century below 2°C, relative to preindustrial levels, with an ultimate target of 1.5°C.

Environment expert  Alter Mbele said the healing of  the Ozone layer gives hope for climate mitigation action implemented around the world.

“The findings of the Scientific Assessment of Ozone Depletion: 2022, showing the ongoing healing of the Ozone layer, is a demonstration of what global agreements can achieve, and an inspiration for more ambitious climate change action to halt a rise in world temperatures and achieve the 1.5 degrees,” she said.

According to the report, the ozone layer could return to its 1980 value in about 2045 for the Southern Hemisphere and about 2035 for the Northern Hemisphere.

“The Antarctic ozone hole is expected to gradually close, with springtime total column ozone returning to 1980 values shortly after mid-century [about 2065],” reads the report. 

In 2016, the Montreal protocol was revised in Kigali, Rwanda, which recommended a phase-down of production of hydrofluorocarbons to avoid additional warming of the ozone layer.

Hassan Ali Mubarak, chair of the UNEP executive committee, added that phasing down hydrofluorocarbons can avoid up to 0.4°C of global warming this century. 

“Given that every fraction of a degree counts for vulnerable communities and nations facing the impacts of climate change, this potential saving is hugely significant. It can save lives.”

In September, scientists from Nasa and the National Oceanic and Atmospheric Administration reported that the hole in the ozone layer was continuing to shrink.

“Often held up as a success story for international environmental negotiation, the Montreal Protocol has relevance for modern efforts to cut carbon emissions and mitigate climate change,” the UN said. 

During the United Nations Framework Convention on Climate Change (COP27) in Egypt at the end of last year, many countries recommitted to the goal of the 2015 Paris climate agreement — to limit global warming to 1.5 °C above pre-industrial temperatures.

But, many countries in the West have continued to import coal and gas from African countries to stabilise their energy grid. The United Kingdom last year opened a new coal mine shortly after COP27 to deal with its energy crunch.

Professor Petteri Taalas, secretary general of the World Meteorological Organisation, encouraged countries to continue decreasing their reliance on fossil fuels.
“Ozone action sets a precedent for climate action. Our success in phasing out ozone-eating chemicals shows us what can and must be done, as a matter of urgency, to transition away from fossil fuels, reduce greenhouse gases and so limit temperature increase,” Taalas said.