NEW DELHI :
China continues to emit an increasing amount of ozone depleting chlorofluorocarbons (CFCs), despite a global initiative to phase out CFCs under the Montreal Protocol, aggravating the climate crisis, scientists have found.
The international team of scientists from the UK, South Korea, Japan, the US, Australia and Switzerland who conducted the study have published their latest findings in the journal Nature.
“We used our atmospheric chemical transport models to show that annual emissions of CFC-11 from eastern China had increased by around 7,000 tonnes every year after 2012," said Luke Western, a post-doctoral researcher at the University of Bristol, who was part of the study. The increase accounts for 40-60% of the global rise in emissions of CFC-11, which is the second-most abundant CFC in the atmosphere.
The findings are also globally significant as the emissions violate the 1987 Montreal Protocol, under which developing countries were required to phase-out production of CFCs.
The results are also disconcerting because the emissions had been declining substantially since the mid 1990s, until 2012, when climate scientists were surprised by a ‘sudden, unexpected’ upward trend of global emissions of CFC-11.
There were indications that some region in eastern Asia was still emitting thousands of tonnes of CFC-11, but the exact location was not known.
Scientists used high-frequency atmospheric observations from South Korea and Japan monitoring stations and global monitoring data to run sophisticated simulations that determined the origin of the polluted air samples.
The clue to the location of the new CFC-11 emissions came from an Advanced Global Atmospheric Gases Experiment (AGAGE) station in South Korea and an affiliated station in Japan.
“Our measurements show spikes in pollution, when air arrives from industrialized areas. For CFC-11, we noticed that the magnitude of these spikes increased after 2012, indicating that emissions must have increased from somewhere in the region," said one of the lead authors, professor Sunyoung Park from Kyungpook National University, South Korea.
CFCs used as foaming agents for building insulation, refrigerators and other consumer products are mainly responsible for depleting the Earth’s ozone layer, which protects us from the sun’s ultra-violet radiations.
What is more disconcerting is that a major chunk of these emissions are probably the result of “new unreported production and use".
“We looked at estimates of the amount of CFC-11 that could be locked up in insulating foams in buildings or refrigerators made before 2010, but the quantities were far too small to explain the rise. The most likely explanation is that new production has taken place before the end of 2017, which is the period covered in our work," said another lead author, Matt Rigby of the University of Bristol.
China, the US, and the European Union are the top three emitters of greenhouse gases and contribute to more than half of the total global emissions. The latest findings cast shadow on the global climate action as the fight to protect the planet from more adverse effects of climate change becomes crucial.
“The study represents a particularly policy-relevant milestone in atmospheric scientists’ ability to tell which regions are emitting ozone-depleting substances, greenhouse gases, or other chemicals, and in what quantities," said co-author Professor Ray Weiss from the University of California San Diego.