By David E. Hubler
Contributor, In Homeland Security
Emissions from an ozone-destroying chemical are on the rise again. That’s the conclusion of a new study by the National Oceanic and Atmospheric Administration, published on May 23 in the journal Nature.
The NOAA analysis of long-term atmospheric measurements found that emissions from the chlorofluorocarbon (CFC) known as CFC-11 have significantly increased. The study says the unexpected increase is likely due to “new, unreported production from an unidentified source in East Asia.”
CFC Chemicals Have Been Used in Hundreds of Commercial Products
CFC chemicals were once considered a triumph of modern chemistry. As a result of their stability and versatility, CFCs were used in hundreds of products, everything from military systems to aerosol spray cans.
CFC-11 is the second most abundant ozone-depleting gas in the atmosphere because of its long life, the NOAA study said. “Continuing emissions from a large reservoir of the chemical can be found in foam building insulation and appliances manufactured before the mid-1990s. A smaller amount of CFC-11 also exists today in older refrigerators and freezers.”
Montreal Protocol Reduced Chlorofluorocarbons in the Atmosphere
The 1987 multinational Montreal Protocol on Substances that Deplete the Ozone Layer was designed to protect the ozone layer. It was instrumental in reducing the abundance of ozone-depleting substances such as chlorofluorocarbons.
The Montreal Protocol was particularly helpful in reducing trichlorofluoromethane (CFC-11) in the atmosphere. It “has made the second-largest contribution to the decline in the total atmospheric concentration of ozone-depleting chlorine since the 1990s,” NOAA noted.
“However, CFC-11 still contributes one-quarter of all chlorine reaching the stratosphere, and a timely recovery of the stratospheric ozone layer depends on a sustained decline in CFC-11 concentrations,” NOAA added.
More Work Is Needed to Determine Cause of CFC Increase
The NOAA researchers’ three-dimensional model simulations confirmed the increase in CFC-11 emissions. However, the increase appears “unrelated to past production; this suggests unreported new production, which is inconsistent with the Montreal Protocol agreement to phase out global CFC production by 2010,” the NOAA study said.
According to the study’s lead author, NOAA scientist Stephen Montzka, “This is what’s going on, and it is taking us away from timely recovery of the ozone layer.”
He said, “Further work is needed to figure out exactly why emissions of CFC-11 are increasing, and if something can be done about it soon.”
CFC production controls took effect in the late 1980s. The findings of Montzka, his team, researchers from the Cooperative Institute for Research in Environmental Sciences (CIRES), the UK, and the Netherlands represent the first time that emissions of one of the three most abundant, long-lived CFCs have increased for a sustained period since production controls took effect in the late 1980s.