Old fridges found to be leaking ozone-destroying CFCs

In 2016, the first signs of healing in the Antarctic ozone layer were discovered, prompting hope that efforts by countries around the world to phase out production of CFCs was working.

But scientists were still finding unexpectedly high emissions of CFC-11 and CFC-12, raising the possibility that they may still be in production in a country breaching its responsibilities as laid out in the 1987 Montreal Protocol.

Concerns were raised last year that China was not sticking to the agreement, which bans CFC production globally, but recent data suggests the country has now clamped down on illegal production of the chemical.

Despite this, emissions of CFC-11 and 12 are still larger than expected.

The researchers now believe that old banks of deteriorating devices that used CFCs in their production, like refrigerators and insulation, are slowly leaking these chemicals back into the atmosphere.

They believe that if left unchecked, it would delay the recovery of the ozone hole by six years and add the equivalent of 9 billion tonnes of carbon dioxide to the atmosphere - an amount that is similar to the current European Union pledge under the UN Paris Agreement to reduce climate change.

“Wherever these CFC banks reside, we should consider recovering and destroying them as responsibly as we can,” said co-author of the study Susan Solomon. “Some banks are easier to destroy than others. For instance, before you tear a building down, you can take careful measures to recover the insulation foam and bury it in a landfill, helping the ozone layer recover faster and perhaps taking off a chunk of global warming as a gift to the planet.”

The team also identified an unexpected and sizeable source of another ozone-depleting chemical, CFC-113.

This chemical was traditionally used as a cleaning solvent, and its production was banned, except for in one particular use, as a feedstock for the manufacturing of other chemical substances. It was thought that chemical plants would use the CFC-113 without allowing much leakage, and so its use as a feedstock was allowed to continue.

Based on their calculations, the researchers believe if all banks were destroyed back in 2000, the measure would have saved the equivalent of 25 billion tonnes of carbon dioxide between 2000 and 2020, and there would be no CFC emissions lingering now from these banks.

In a second scenario, the researchers said, if the CFC banks are dismantled in 2020, it would help the ozone layer recover six years faster.