Industry in northeastern China has released thousands of tons of a CFC gas banned by international treaties, according to a new study, detailed by The Guardian.
The chemicals were banned in the 1987 Montreal protocol, after having been widely used in the 70s and 80s for refrigerants and to produce insulation. Global emissions of Chlorofluorocarbon-11 (CFC-11) declined steadily until 2012.
“CFCs are the main culprit in depletion of the stratospheric ozone layer, which protects us from the sun’s ultra-violet radiation,” said the study’s lead author Matt Rigby, a University of Bristol atmospheric chemist.
Increases in CFC emissions will prevent the ozone layer, including a hole over Antarctica, from recovering.
But since 2013, emissions from the region have increase 7,000 tons. And the overall slowdown of global emissions slowed by half between 2013 and 2017. While readings from remote monitoring stations did suggest an origin in east Asia, they weren’t able to pinpoint a location.
Along with an international team of scientists from the US, UK, Australia, Switzerland, and South Korea, Rigby used data from closer monitoring stations to pinpoint the location. Data from monitoring stations in Japan and Taiwan, along with computer simulations, pointed to an origin in northeastern China.
“Our measurements show ‘spikes’ in pollution, when air arrives from industrialized areas. For CFC-11, we noticed that the magnitude of these spikes increased after 2012, indicating that emissions must have grown from somewhere in the region,” according to Sunyoung Park of Kyungpook National University, a lead author and head of the South Korea monitoring station.
Reports last year had suggested that foam factories in Shandong and Hebei province were likely to blame, and shortly afterwards, several factories were shuttered by authorities with no explanation. The new research appears to confirm that suspicion.
“From the Korean and Japanese data, we used our models to show that emissions of CFC-11 from eastern China had increased by around 7,000 tonnes per year after 2012, particularly in or around the provinces of Shandong and Hebei,” said Dr. Luke Western of the University of Bristol.
As a greenhouse gas more potent than methane or carbon dioxide, CFC-11 in the atmosphere could also contribute to climate change. And it remains in the atmosphere for about a half century.
While evidence has shown recovery in the ozone “hole” over Antarctica, a study last year indicated a decline in the ozone layer in the lower stratosphere over mid-latitude areas. CFCs have primarily affected the ozone layer in the upper stratosphere and over the poles, and scientists believe other chemicals and climate change may be driving this unexpected decline.