A new report reveals the possibility that an already-banned chemical is still being produced as its emissions slow down in decline. What exactly are chlorofluorocarbons (CFCs), and why were they banned?
CFC Emissions Returning?
A recent report revealed that emissions of CFC-11 are rising again after years of already being banned. The analysis, which is based on National Oceanic and Atmospheric Administration (NOAA) long-term readings of CFC emissions in the atmosphere, showed that the rate of decline of CFC-11 has slowed by 50 percent since 2012.
This could mean that production of CFC-11 may still be ongoing in an unknown location despite the chemical being banned in 2010. If this is not controlled and abated, the emissions could slow down the healing process and recovery of the ozone layer.
"It is therefore, critical that we take stock of this science, identify the causes of these emissions and take necessary action," said UN Environment in a statement.
What Are CFCs?
CFCs are non-toxic, non-flammable chemicals that contain atoms of chlorine, halogen, carbon, and fluorine. It was first synthesized by Thomas Midgley, Jr. Of General Motors in 1928 as safer refrigerants, and in 1932, Carrier Engineering Corporation used Freon-11 or CFC-11 on the world's first self-contained home air-conditioning system. They were also used in the production of aerosol sprays, blowing agents, refrigerants, packing materials, and solvents.
CFCs were widely used in a variety of products, but in 1974, chemists from the University of California showed how CFCs could become a major source of inorganic chlorine in the stratosphere. The concerning thing about CFCs is that while they are inert in the lower atmosphere, they undergo a change in the stratosphere where they become active in the destruction of the ozone.
By 1985, researchers described a worsening depletion of the stratospheric ozone. Just two years later in 1987, 27 countries signed the Montreal Protocol, which aimed to cut the production of CFCs in half by the year 2000. The treaty included reducing the production of CFC-11, -12, -113, -114, -115, and Halons.
By 2010, the production of CFC-11, the second most abundant CFC, was completely ended, as the ozone continued to heal and recover. In fact, just last year, NASA announced that the ozone hole over Antarctica has shrunk to its smallest since 1988.
Why Is The Ozone Important?
In the stratosphere, ozone does the very important job of trapping and absorbing potentially harmful UV radiation. It is because of the ozone that plants, animals, and humans are protected from the harmful radiation of the sun. Without it, radiation levels that could cause severe biological damage could reach the Earth's surface.