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Home / Science / The mysterious rise of ozone-depleting chemicals goes back to eastern China

The mysterious rise of ozone-depleting chemicals goes back to eastern China



Two provinces in China are a source of alarming increases in emissions from a globally banned chemical that causes damage The Earth's protective ozone layer, according to a study released Wednesday, has alarmed scientists who pollute the atmosphere monitor the planet.

The study, published in the journal Nature, comes to the conclusion one year after another report that air samples had an amazing surplus of ozone. A type of chlorofluorocarbon known since 2012 as trichlorofluoromethane or CFC-11.

This manufactured chemical, which used to be widely used to blow polyurethane into a rigid insulating foam, leaks into the air and destroys ozone molecules in the upper atmosphere. The ozone layer is vital and limits the amount of harmful ultraviolet solar radiation that reaches the planet's surface. CFC-11 is also a powerful greenhouse gas with about 4,750 times the potential for carbon capture.

The new report highlights the need to enforce international environmental agreements, even when the risks are clear and profound. And it is a reminder that China's increasing environmental problems have global consequences.

"This is a huge problem," a State Department official said Wednesday. The official said the department is planning to review the report, but has not yet concluded that China is the source of the new emissions.

"If there is a problem in another country, we will suffer as well," said the official


Dacheng Desheng Chemical Co., Ltd. staff. in Hebei province, China, show barrels of CFC-11 according to EIA, US sources. (Environmental Investigation Agency, USA)

Every production and use of CFC-11 is one Violation of the Montreal Protocol, an agreement of 1987, in which such chemicals were withdrawn from circulation so as not to harm the atmosphere. The global agreement was reached after scientists revealed the presence of an expanding hole in the ozone layer over the Antarctic.

Last year's report did not identify the source of the new emissions, except that they most likely came from East Asia. However, the authors of the new report identify the provinces of Shandong and Hebei in eastern China as a likely source for at least 40 percent of emissions.

The researchers based their conclusion on air samples from monitoring stations in South Korea and Japan. These sampling stations with instruments that can filter out the molecular components of the air had periodic peaks in CFC-11. Researchers combined this data with weather forecasts and observations of wind patterns and conducted a series of computer models to pinpoint the most likely source of emissions. The results indicated the two Chinese provinces.

"When the wind blows in a straight line from this source to the station, you'll see a spike," said lead author Matt Rigby, an atmospheric scientist at the University of Bristol.


Scooter riders are waiting to cross a road on a heavily soiled day in Shijiazhuang, Hebei Province in 2016. (GREG BAKER / AFP / Getty Images)

"We hope to work with Chinese colleagues in the future to see if similar signals are visible in their data," said Rigby.

The Montreal Protocol is often cited as a model for global cooperation in protecting the US Environment and what nations can work together to address climate change – another tragedy of the crisis that is triggered by the burning of fossil fuels and other human activities.

The parties to the Protocol were alerted by last year's report, calling for "urgent action" to investigate the sources of emissions and enforce the international agreement.

"We can not relax our vigilance for a second, we can not Tina Birmpili, Head of the United Nations Ozone Secretariat last summer said

The protocol has worked largely as intended, and the authors of the new report reaffirm this key message: The ozone layer continues despite signs of new emissions

The problem is that recovery may be slower than expected, with concentrations of CFC-11 in the atmosphere not falling as fast as computer models predicted.

There may have been relatively benign explanations. In the built world is already a large part of the CFC -11 "piled up" in the form of an insulation, which gradually releases the gas into the atmosphere. Rigby and his colleagues investigated the possibility that the construction of new buildings and the replacement of existing buildings and the destruction of older infrastructures could have blown up the chemical.

The numbers, however, did not add up. The most likely explanation is the new production and use of the chemical.

Rigby said the new CFC-11 emissions have the global warming equivalent of the total annual carbon footprint of human activity in the city of London. [19659026] Stephen Montzka, a scientist from the National Oceanic and Atmospheric Administration and co-author of the Wednesday study, and the 2018 report said the latest findings left important questions unanswered. While researchers traced approximately half of the disruptive CFC-11 emissions to China's two provinces, details of the source of other emissions are not yet known.

"The guessing game is: Where's the other half coming from?" Montzka said, pointing out that the study only described in detail emissions in a limited region of China, which covers about one-third of the population.

"Where does the rest come from? We do not know it.

The increase in CFC-11 emissions raises other questions as to why it would still be manufactured by anyone. The short answer is that CFC-11 is preferred by some companies because it is cheaper and more effective than climate-friendly alternatives. This is the result of a survey published last year by the Environmental Investigation Agency, a Washington-based Environmental Watchdog Group.

Researchers spoke to representatives of 18 companies in 10 Chinese provinces who had admitted their use of the banned chemical. Six of these companies were in Shandong and Hebei.

Following the announcement of new emissions last year, the Chinese authorities, according to Avipsa Mahapatra, who works for CFCs, stopped the illegal use of CFCs, confiscated 29 tons of chemicals and closed down some of the rogue factories.

But she said that the Nature paper states that this confiscated material represents only a fraction of what is produced and used. She said her investigators talked with companies that concealed their use of CFC-11, for example, by showing legal chemicals that could be shown to government inspectors.

"We are just starting to understand the scale of the problem," she said.

Montzka said he was confused about the return of CFC-11.

"The exit was to take place in 2010 – and I think that was the case," he said. "Why did it come back?"

This could be a case in which the early detection of illegal production could lead to measures restricting their use, which would minimize the effects on the ozone layer, he said. Given that the chemical typically leaks out of the foam over the decades, the full extent of the problem remains unknown.

"There is a possibility that we have only seen the tip of the iceberg so far." Montzka said. "If what we've discovered is actually just a small part of the additional new illegal production that has taken place since 2010, the problem could be greater than what we've discovered so far."


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