Ozone Layer Wins! Emission of Dangerous CFC Halted

Once used in refrigerants and foam insulation, illegal emissions of an ozone-destroying chemical have practically come to a halt. Scientists announced this week, almost three years since the rogue emissions were first recorded. The outcome is a big victory for the international convention that safeguards the ozone layer, researchers say.

In May 2018, researchers reported a mysterious spike in trichlorofluoromethane1, or CFC-11, atmospheric concentrations that had begun around 2013. Under the Montreal Protocol, a legally binding treaty has been remarkably successful in curbing the use of ozone-depleting substances.

Decrease in production

Chemical production has been banned since 2010, so scientists assumed that the sudden increase was likely the result of a new source of illegal emissions. Scientists traced the bulk of the emissions to eastern China by May 2019. The country has committed itself to rectify the problem in response to considerable international pressure.

Scientists report that atmospheric concentrations of CFC-11 have fallen precipitously since 2018 in a pair of studies reported in Nature on the 10th of February. The damage to the ozone layer from several years of illegal emissions will be trivial, assuming the current trend continues, says Stephen Montzka, an atmospheric chemist at the National Oceanic and Atmospheric Administration in Boulder, Colorado, who led one of the studies.

The treaty did its job," says Durwood Zaelke, president of the Washington DC-based advocacy group, the Institute for Governance & Sustainable Development." "They got their act together, whoever the offending parties were, including most definitely China." The origins of illicit pollution outside China, though, remain a mystery.

The Ministry of Ecology and the Environment of China have not responded to many requests for comments regarding the latest results and actions it has taken to stop illegal emissions of CFC-11.

Global CFC Monitoring

CFC-11 has survived in the atmosphere for nearly 50 years, so global pollution can decrease by approximately 2 percent annually if sources are entirely removed.

However, due to the continuing pollution of the material from old refrigeration devices and insulating foam as buildings are destroyed, the real amount is slower.

CFC-11 emissions dropped by about 0.85 percent a year between 2002 and 2012. Since 2013, though, the rate halved to around 0.4 percent, an indication that someone dumped nearly 13,000 tons of newly generated CFCs into the atmosphere a year, the Montzka team estimated in 2018. The processing and use of foam insulation were the most possible culprit.

Data Gaps

However, the study did not account for any of the decrease in pollution, which leads to deficiencies in data collection worldwide, including in countries such as India and Brazil that are industrially significant.

"We really don't know where the other 40 percent came from," says Martin Vollmer, an atmospheric scientist at the Swiss Federal Laboratories for Materials Science and Technology in Dübendorf, although 60 percent of the recent decrease was accounted for."

The episode, though, should give a warning signal to anyone who may be tempted in the future to break the rules.

Net Zero Emission

Virtually every nation has signed the Paris Climate Change Deal, aiming to maintain the global temperature above pre-industrial levels at 1.5 °C. However, as we manage to churn out the pollutants that cause climate change, temperatures will continue to climb high above 1.5, to levels that endanger people's lives and livelihoods everywhere.

This is why an increasing number of countries are making promises over the next few decades to reach climate neutrality or "net-zero" emissions. This is a considerable challenge, demanding bold steps to start right now.

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