[ad_1]
A chemical banned worldwide for 30 years has unfortunately made a comeback. And all the signs, in a new study, designate China as the culprit.
In the 1980s, countries joined together to sign the Montreal Protocol on Substances that Deplete the Ozone Layer, a landmark treaty to halt and reduce the production of chlorofluorocarbons (CFCs), chemicals used in refrigerators and foams the ozone layer of the Earth.
The Montreal Protocol was signed by 197 countries around the world, including Canada, the United States and China. While the ozone layer in our upper atmosphere was slowly depleting – allowing an increasing amount of ultraviolet radiation to penetrate the sun – the protocol was contributing to a significant reduction in harmful CFCs, which in turn allowed for a slow healing of the UVC layer. ozone damaged.
That's up until last year, when scientists from the National Oceanic and Atmospheric Association found that global emissions of trichlorofluoromethane (CFC-11) actually increased since 2013.
The increase implied that someone was secretly violating the Montreal Protocol. But the limitations of measuring devices meant that the location of the polluter could only be located somewhere in East Asia.
In a new study published in Nature on May 22, scientists at the University of Bristol, Kyungpook National University and the Massachusetts Institute of Technology revealed that between 40 and 60% of total global CFC emissions -11 came from east China.
With the help of an international network of measuring devices designed to identify and track gases in the atmosphere, the team at the origin of the study found that the data from their devices in Korea and Japan had increased sharply since 2013. After analyzing weather conditions and wind regimes to determine the origin of the gas increase, it has them drove east to mainland China, around Shandong Province.
"It was not entirely a surprise," said Matthew Rigby, lead author of the study and a reader of atmospheric chemistry at the Bristol University School of Chemistry. A few months after the release of the initial report last year, the Environmental Investigation Agency and the New York Times released reports in which Chinese manufacturers in the region confirmed that they were using CFC-11 in the foam production.
The manufacturers told EIA that they continued to use the banned product because of its better quality and lower price. The New York Times reported that some factories were secretly producing gas, while other manufacturers said local governments had turned a blind eye.
However, Rigby said scientists and watchdogs did not know how much the manufacturers in China emitted – about 7,000 tonnes of CFC-11 since 2013 in that region alone.
"It's more than double the emissions we expected from China at the time," he said. "Was that enough to explain a substantial fraction of the increase in global emissions we have seen? What we found in this study is that, yes, it is important around the world. "
Rigby also mentions that CFC-11 is a greenhouse gas, "about 5,000 times more potent than carbon dioxide for global warming."
The Chinese government has cracked down on illegal manufacturers of CFC-11 and shut down production facilities. Rigby hopes that this new study will help law enforcement to look for illicit producers.
Due to the limited locations of their monitoring network, Rigby stated that the study team could not conclusively determine the source of other CFC emissions, pointing out that it did not have information on areas such as South America, Western China and India.
According to a United Nations report from 2018, due to the progress of the Montreal Protocol, the huge ozone hole that is forming over Antarctica could be completely healed by now the middle of the century.
Rigby, however, added that if the increase in emissions from the east of China does not stop soon, the healing process could be delayed by "potentially several decades".
Copyright Postmedia Network Inc., 2019
RELATED
[ad_2]
Source link