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article imageScientists pinpoint source of ozone-destroying chemical

By Karen Graham     May 22, 2019 in Science
Scientists are zeroing in on the source of a powerful climate pollutant that was banned years ago but has mysteriously been increasing, with potentially damaging consequences for climate change.
The 1987 Montreal Protocol was designed to protect the stratospheric ozone layer by reducing the production and use of ozone-depleting substances called CFCs in order to protect the Earth's fragile ozone layer. Under the Montreal Protocol, the world agreed to end the production of CFC-11 altogether by 2010.
The protocol has proved to be highly successful over the years as countries voluntarily stopped the production of trichlorofluoromethane, or CFC-11, the second most abundant ozone-depleting gas, commonly used in refrigerants, aerosol sprays, and old Styrofoam.
In 2016   CIRES scientist Lei Hu and NOAA scientist Stephen Montzka investigated the concentrations ...
In 2016, CIRES scientist Lei Hu and NOAA scientist Stephen Montzka investigated the concentrations of CFC's in the stratosphere. Their latest findings show CFC's levels are in fact, rising.
Source: NASA / NOAA
In a study published last year in March, researchers identified an unexpected and persistent increase in CFC-11, more than likely from new, unreported production. After the research team ruled out other possible explanations for the rise in concentrations of CFC-11, they were left with only one conclusion - Someone is cheating.
Now, scientists have pinpointed the location of the emissions of CFC-11. Their findings, published in the journal Nature on Thursday, shows that eastern China is responsible for upwards of 60 percent of the recent rise in CFC-11 emissions.
To be specific, the findings found that the source of the CFC-11 emissions originated in and around the Chinese provinces of Shandong and Hebei. Additionally, they appear to be the result of new production of the dangerous chemical - in direct violation of the 1987 Montreal Protocol.
a  Measured global surface rates for N2O (grey line)  CFC-12 (thin blue lines)  and CFC-113 (thin gr...
a, Measured global surface rates for N2O (grey line), CFC-12 (thin blue lines), and CFC-113 (thin green lines) from flasks analysed by GC–ECD and also, for the CFCs, by GC–MS. b, Hemispheric differences measured for CFC-12 and N2O. c, Hemispheric differences measured for CFC-113. Multiple CCM simulation results appear in a, b, and c for CFCs as thick dark lines and are updated only annually.
M. Rigby, el. al.
According to the study authors, the Chinese government recently identified and shut down two small-scale CFC-11 manufacturing facilities, but those couldn't have accounted for the magnitude of the emissions increases in the study. Hopefully, the new findings will lead to the Chinese looking into the issue a lot more carefully.
Stephen Montzka, a co-author of the study and National Oceanic and Atmospheric Administration researcher, talking about the Chinese search for the culprits producing the chemical said: "I think there is less wiggle room for them to say, 'we've looked and we don't see it,' Montzka said. "It's a matter now of maybe looking more carefully."
Map of eastern China. Hebei province is at the top  and Shandong province is right below it.
Map of eastern China. Hebei province is at the top, and Shandong province is right below it.
Failure of the Chinese to rein in the illicit production of the CFC-11 could lead to even greater damage to the ozone layer protecting Earth and to damage to the Montreal Protocol.
It's "the only successful protocol," Andreas Stohl of the Norwegian Institute for Air Research said of the binding international agreement that has been ratified by more than 190 countries. "If you start violating it without consequences, if China can do it, why not India and why not other countries? I think we have to stop this immediately."
More about CFC11, Montreal protocol, trichlorofluoromethane, China, Ozone hole
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