The conclusions of a team of researchers led by Huabo Duan, an associate professor in the Department of Civil Engineering at Shenzhen University, comes hot on the heels of another study undertaken by the US National Oceanographic and Atmosphere Administration (NOAA) published earlier this month.
This highlighted a dramatic rise in the level of a chlorofluorocarbon called CFC-11 emissions and suggested that the source was East Asia, but was unable to be more specific, with lead author Stephen Montzka saying: “It really looks like somebody is making it new.”
But Mr Duan’s report, which has been published in the Environmental Science and Technology journal, goes further, suggesting poor recycling techniques in China are to blame.
Entitled Chilling Prospect: Climate Change Effects of Mismanaged Refrigerants in China, it traces the increase in emissions to repair shops which cut up refrigerators and air conditioning units (RACs) containing CFC-11, selling the metal for scrap.
The study’s authors warn: “Based on field surveys and a dynamic model, we reveal the lingering ozone depletion potential (ODP) and significant global warming potential (GWP) of scrap refrigerants in China, the world’s largest producer (62 percent) and consumer (46 percent) of RACs in 2015, which comes almost entirely from air conditioners rather than refrigerators.
“Our results imply an urgent need for improving the recycling and waste management of RACs in China.”
Reed Miller from Yale University in New Haven, Connecticut, who took part in the research, added: “There has been a lesser global emphasis on collecting such refrigerants at the end of their lives.”
CFC-11 was once used in refrigerators, but in 2006, its manufacture was outlawed under the Montreal Protocol, which regulates chemicals which damage the ozone layer.
Therefore Mr Montzka and his team were stunned to discover a 25 rise in emissions which he admitted could slow down the shrinking of a hole in the ozone layer, which protects us from the Sun’s harmful ultraviolet rays.
Speaking after the publication of the Shenzhen University report, Mr Montzka sounded a note of caution.
He said: “The emissive source of CFC-11 that is mentioned in the ES&T paper is more than one order of magnitude smaller than is needed to explain my atmospheric observations.
“Sure, the process mentioned in the ES&T paper may contribute, but their best estimate of CFC-11 emission from this activity is an amount that is not playing any appreciable role in the emission increase we reported on.”
The ozone layer above the Antarctic has been particularly badly damaged since the mid-1980s, where low temperatures speed up the conversion of CFCs to chlorine, which in turn reacts with oxygen atoms in ozone and rips apart the ozone molecule.
Scientists predict it will take another 50 years for chlorine levels in the atmosphere to fall to pre-industrial levels.
However, these estimates were based on the assumption that no additional CFCs were being released – assumptions challenged by the most recent research.