A chemical banned around the globe for the last 30 years has made an unfortunate resurgence. And all signs, in a new study, point to China as the culprit.
In the 1980s, countries came together to sign The Montreal Protocol on Substances that Deplete the Ozone Layer, a landmark treaty designed to halt and reduce the production of chlorofluorocarbons (CFC), chemicals used in fridges and foams that had the side effect of tearing through the Earth’s ozone layer.
The Montreal Protocol has been signed by 197 countries around the world, including Canada, the U.S., and China. As the ozone layer in our upper atmosphere slowly depleted — letting in an increasing amount of the sun’s ultraviolet rays — the protocol contributed to a significant reduction in harmful CFCs, which then allowed for a slow healing of the damaged ozone layer.
That is until last year, when scientists from the National Oceanic and Atmospheric Association found that global emissions of Trichlorofluoromethane (CFC-11) have actually been increasing since 2013.
The increase implied that someone was secretly violating the Montreal Protocol. But the limitations of measuring devices meant the location of the polluter could only be traced to somewhere in east Asia.
Now, in a new study published in Nature on May 22, scientists from the University of Bristol, Kyungpook National University, and the Massachusetts Institute of Technology found that between 40 and 60 per cent of total global CFC-11 emissions originate from eastern China.
With the help of an international network of measurement devices designed to identify and track gases in the atmosphere, the team behind the study found that data from their devices in Korea and Japan has spiked since 2013. After analyzing weather and wind patterns to determine the origin of the gas increase, it led them to eastern mainland China, around the Shandong province.
“It wasn’t entirely a surprise,” said Matthew Rigby, lead author of the study and Reader in Atmospheric Chemistry in the School of Chemistry at the University of Bristol. A few months after the initial report was released last year, both the Environmental Investigation Agency and the New York Times published reports in which Chinese manufacturers in the region confirmed they were using CFC-11 in the production of foams.
Manufacturers told the EIA they continued to use the banned product because of its better quality and cheaper price. The New York Times reported thatsome factories were producing the gas in secret, while other manufacturers said the local governments turned a blind eye.
However, Rigby said scientists and watchdogs didn’t know just how much manufacturers in China were emitting — about 7,000 tonnes of CFC-11 since 2013 in that area alone.
“That’s more than double the emissions we were expecting from China at the time,” he said. “Was this enough to account for a substantial fraction of the global emissions rise that we saw? What we’ve found in this study is that, yes, it is globally significant.”
Rigby also mentions that CFC-11 is a greenhouse gas, about “5,000 times more potent than carbon dioxide at warming the climate.”
The Chinese government has been cracking down on illegal CFC-11 manufacturers and shutting down production facilities and Rigby hopes this new study will help law enforcement officials in their search for illicit producers.
Due to the limited locations of their monitoring network, Rigby said the study team cannot conclusively determine where the rest of the CFC emissions are coming from, pointing out they have no information on regions such as South America, western China and India.
According to a 2018 United Nations report, due to the progress of the Montreal Protocol, the huge ozone hole that forms above Antarctica could be completely healed by the mid-century.
But Rigby said if the increased emissions from eastern China aren’t stopped soon, the healing process could be delayed by “potentially decades.”