Industries in northeastern China have emitted large amounts of ozone-depleting gas into the atmosphere in violation of an international treaty, world scientists say.
And this slows the recovery rate of the hole in the ozone layer.
The ozone layer is an area of the stratosphere of the Earth, which essentially acts as a shield and absorbs most of the sun's ultraviolet (UV) radiation.
So, when in 1985 scientists discovered that there was a hole in Antarctica and Australia, that was very worrying news.
Then we all gathered and banned the use of harmful gases that depleted the earth's protective layer in the 1987 Montreal protocol and has been recovering ever since.
China has signed the Montreal protocol, but it seems that the country has not kept its deal.
From 2013, annual emissions from northeastern China to a forbidden chemical called CFC-11 increased by about 7,000 tonnes, researchers reported overnight in the reviewed journal nature,
"This increase is a significant part (at least 40 to 60%) of the global increase in CFC-11 emissions," they write.
Prior to removing CFC-11 or chlorofluorocarbon-11, it was widely used in the 1970s and 1980s as a refrigerant and foam insulation. The chemical is a major cause of ozone depletion.
Since the ban, the concentration of chemicals in the atmosphere has been steadily decreasing, but last year scientists have found that the pace of this delay has halved from 2013 to 2017. Since the chemical is not found in nature, change can only be made from new emissions.
The use of high-frequency atmospheric observations from Gosan, South Korea and Hateruma, Japan, together with global monitoring and simulation data on the chemical chemical transport model, researchers investigate the likely culprit and point their finger in eastern China.
Last year's reports from the Environmental Research Agency showed Chinese foam factories in the Shandong province and Hebei's inner province surrounding Beijing.
Suspicions were increased when the authorities subsequently excluded some of these facilities without explanation.
Manufacturers say they continue to use the forbidden product because of its better quality and lower price.
The New York Times reported that some factories are producing secret gas, while other manufacturers say local authorities are closing their eyes.
"It was no surprise," says Matthew Rigby, lead author of the study and Reader in Atmospheric Chemistry at the Chemistry School at Bristol University.
Paul Fraser, an honorary associate at the Australian Center for Climatology, CSIRO and co-author of the paper, said that while the eastern part of China was about half the increase in CFC-11, world scientists did not have the technology to monitor large portions of the rest from the world.
Together with other scientists, he presented the data of the Chinese authorities last year and optimistic actions will be taken to reduce the damage caused by emissions.
"They were concerned that it is clear that I think … they will deal with this," he told Radio ABC this morning.
But for now, he has not seen or heard any signs that China has begun to deal with the counterfeit factories that are believed to be responsible.
Since scientists have noticed the chemical increase in the atmosphere earlier, "it gives us a really good chance to make sure they do not do too much damage," he said.
But pouring more CFC-11 into the air can also prevent the return of ozone to normal levels, scientists warn.
"If emissions do not decrease, it will slow the recovery of the Antarctic ozone hole, probably over decades," Fraser said.
– With AFP