Industries in northeastern China have released large amounts of ozone-depleting gas into the atmosphere, in violation of an international treaty, according to scientists around the world.
And this slows down the recovery rate of the hole in the crucial layer of ozone.
The ozone layer is a region of the Earth's stratosphere that acts essentially as a shield and absorbs most of the sun's ultraviolet (UV) radiation.
So when scientists discovered in 1985 that there was a hole in Antarctica and Australia, it was very disturbing. After that, we all came together to ban the use of harmful gases that deplete the protective layer of the Earth in the Montreal Protocol of 1987. Since then, the recovery has been more or less slow.
China is a signatory to the Montreal Protocol, but it appears that the country has not fulfilled its commitments.
Since 2013, annual emissions of CFC-11, a banned chemical called CFC-11, have increased by about 7,000 tonnes, researchers reported overnight in a peer-reviewed journal, Nature.
"This increase represents a substantial fraction (at least 40-60%) of the global rise in CFC-11 emissions," they wrote.
Prior to its deletion, CFC-11, or Chlorofluorocarbon-11, was widely used in the 1970s and 1980s for refrigeration and foam insulation manufacturing. The chemical is a major cause of depletion of the ozone layer.
Since the ban, the concentration of the chemical in the atmosphere has steadily decreased, but last year, scientists were surprised to find that the slowdown in this slowdown had been halved between 2013 and 2017. This change not occurring in nature have been produced by new emissions.
With the aid of high-frequency atmospheric observations from Gosan (South Korea) and Hateruma (Japan), as well as simulations of global monitoring data and atmospheric chemical transport models, the researchers investigated the likely culprit and pointed to East China.
Last year, reports from the Environmental Investigation Agency reported Chinese foam plants located in the Shandong Coast Province and Hebei Province inland, which surrounds Beijing.
Suspicions were heightened when the authorities subsequently closed down some of these facilities without explanation.
Paul Fraser, honorary member of the CSIRO Climate Science Center (Australia) and co-author of the paper, said that while East China accounts for about half of the rise in CFC-11, scientists around the world do not have the technology to monitor large parts of the planet. the rest of the world.
With other scientists, he presented the data last year to the Chinese authorities and he is optimistic to take action to reduce the damage caused by emissions.
"They were worried, it was clear, I think … that they were going to tackle this problem," he told ABC radio this morning.
But until now, he has not seen or heard any indication that China has started cracking down on dishonest factories considered responsible.
Because scientists have noticed the chemical increase of the atmosphere very early, "it gives us a very good chance not to cause too much damage," he said.
But, according to scientists, the release of more CFC – 11 into the air could also prevent the return of ozone to normal levels.
"If emissions do not decrease, it will delay the recovery of the hole in the Antarctic ozone layer, probably for decades," Fraser said.