Published: Thu, May 17, 2018
Business | By Pearl Harrison

Banned Ozone-Destroying Chemicals Still In Production, Scientists Baffled

Banned Ozone-Destroying Chemicals Still In Production, Scientists Baffled

An ozone depleting CFC refrigerant, thought to be virtually extinct following Montreal Protocol phase outs, has mysteriously reappeared in increasing amounts in the atmosphere.

Officially, production of CFC-11 is supposed to be at or near zero - at least, that is what countries have been telling the United Nations body that monitors and enforces the Protocol. CFC concentration in the atmosphere has declined by 15 percent from its peak in 1993, but over the past few years, the rate of decline has slowed down. However, in 1987, an global team of scientists proved that the emissions of such chemicals were actually harming the environment, particularly the ozone layer.

Stephen Montzka and colleagues at the US National Oceanic and Atmospheric Administration (NOAA) looked at levels of CFC-11 in the atmosphere using measurements taken at the Mauna Loa Observatory in Hawaii.

These could hamper the recovery of the ozone hole and worsen climate change.

"If the emissions were to persist, then we could imagine that healing of the ozone layer, that recovery date, could be delayed by a decade", said Dr Montzka.

Scientists have detected an unexpected rise in atmospheric levels of CFC-11, a chlorofluorocarbon (CFC) highly damaging to the ozone layer.

The researchers have calculated that an additional 6,500 to 13,000 tons emitted each year in Eastern Asia would be enough to account for the trend. 'The decline in CFC-11 is the graph that we all show in our atmospheric chemistry lectures to illustrate the effectiveness of the ban on CFCs. Some scientists speculate that the substance is likely being produced in East Asia.

The authors of the new report discount the idea that this change could be due to releases from existing stores, emissions from older buildings being decommissioned, or from the accidental production of CFC-11 as a by-product of other chemical manufacture.

The goal of the study was not to point fingers; but figuring out where the emissions are coming from is a crucial environmental question.

Last fall, it was reported that the hole in the Earth's ozone layer had shrunk to its smallest size since 1988, which was great news.

"If these emissions continue unabated, they have the potential to slow down the recovery of the ozone layer", Weller said in a statement. "It is critical that we take stock of this science, identify the causes of these emissions and take necessary action", he said.

Unreported production of CFC-11 outside of certain specific carve-out purposes in the treaty would be a "violation of global law", Weller confirmed, though he said that the Protocol is "non-punitive" and the remedy would probably involve a negotiation with the offending party, or country. Though concentrations of CFC11 in the atmosphere are still declining, they're declining more slowly than they would if there were no new sources, Montzka said. In 2012, however, the rate of decline suddenly reduced by about 50% - indicating that new source of production had started up.

Like this: