Scientists have spotted the mysterious return of ozone-depleting CFC refrigerant gas in the atmosphere.
CFC11 (R11) was a common refrigerant and insulation propellant, but production controls were introduced in the late 1980s. The US stopped manufacturing in 1996 and worldwide production finally ended in 2010. However, according to the National Oceanic and Atmospheric Administration, emissions have been rising again since 2013.
Its findings, which were published in Nature magazine, show a 25% jump in R11 emissions with about 13,000 tonnes released every year since 2013. Clandestine production in East Asia is the main suspect.
CFCs remain one of the most abundant ozone-depleting gases in the atmosphere because of their long life and ongoing emissions from appliances built before the mid-1990s, but concentrations had declined by 15% from their peak in 1993.
Damage to the ozone layer will be ‘minor’ as long as this new source can be pinpointed and shut down quickly, the researchers said.
