Mystery CFC-11 emissions

A study published by an international team of scientists has further identified China as the source of significant CFC-11 emissions, despite it being phased out in 2010 under Montreal Protocol.

The chemical, which is particularly damaging to the ozone layer and has a high global warming potential (GWP) of 4660, was historically used primarily in the production of polyurethane foam.  

Global production of the harmful chemical ended in 2010 but, in 2013, atmospheric monitoring stations began to observe rises in CFC-11 and subsequently, in a report published by the Environmental Investigation Agency (EIA), it was confirmed that CFC-11 was being used in Chinese factories.

The Chinese government reportedly acted quickly to both investigate and close down facilities using illegal CFC-11. While this confirmed that CFC-11 was being used in certain Chinese factories, it and other similar reports could not identify the scale or precise geographical region of the bulk of emissions. 

Global monitoring networks – such as the Advanced Global Atmospheric Gases Experiment (AGAGE) – had registered the increase of CFCs in the atmosphere, but only indicated the source as being somewhere in eastern Asia. This lack of accuracy was in part due to their positioning away from built-up areas, which was designed to grant them a better view of general atmospheric conditions. 

In order to better pinpoint the source of emissions, newer measurement facilities were positioned closer to industrialised areas. These, including an AGAGE site located in South Korea and an affiliated station in Japan, began recording spikes of CFC-11.

An international modelling team based at the University of Bristol in Britain then used this data to build a simulation that could identify the source and scale of these wind-carried emissions – and revealed that the CFC-11 was originating from China. It also indicated that CFC-11 emissions had risen by almost 7000 tonnes per year after 2012.

The report that followed, titled Increase in CFC-11 emissions from eastern China based on atmospheric observations, attributes up to 60 per cent of the global rise in CFC-11 emissions primarily to provinces surrounding Beijing.

Unsurprisingly, the Chinese government was quick to counter the claims. Despite the new report and discovery of previous CFC-11 usage, Ministry of Ecology and Environment spokesperson Liu Youbin stated that large-scale illegal use of CFC-11 had not been found.

Atmospheric monitoring is not without its problems and many regions are not covered, meaning scientists cannot identify other CFC-11 sources.

“The fact that scientists cannot pinpoint the source of the remaining emissions demonstrates the lack of sufficient monitoring capacity in other parts of the world,” said Avipsa Mahapatra, EIA US Climate Campaign Lead.

“This cannot be treated as isolated cases in China and underlines the need to fundamentally revisit the Montreal Protocol’s monitoring and enforcement regime, including expanding approaches to tracking the supply chain of controlled substances.” 

Managing the existing CFCs in circulation, however, must not be overlooked. Project Drawdown, a non-profit organisation focused on identifying and managing environmental issues, suggests that control of already-produced refrigerants is just as critical – stating that, over 30 years, containing 87 per cent of refrigerants likely to be released could reduce emissions equivalent to that of 99 gigatonnes of carbon dioxide.