Scientists have found an unexpected, sharp and mysterious rise in emissions of an ozone-damaging chemical despite a global treaty banning it in 2010.
According to a new research, levels of CFC-11, a chlorofluorocarbon (CFC) which is the second most abundant ozone-depleting gas controlled by the Montreal Protocol, has increased in recent years. The study published in the journal Nature, reveals that the emissions of the chemical can cause a hole in the ozone layer. For those unaware, the ozone layer protects the Earth from the sun’s harmful UV radiation.
Researchers say CFC-11 was seen to be declining following the ban, however, the fall has slowed down by 50% since 2012, which could affect the recovery of the ozone hole and worsen climate change. They add the increase in emissions may be stemming from underreported production of CFC-11, likely from East Asia. The report indicates that from 2014 to 2016, emissions of CFC-11 increased by 25 percent.
“We're raising a flag to the global community to say, 'This is what's going on, and it is taking us away from timely recovery from ozone depletion,'" said lead author of the paper Stephen Montzka, a scientist at NOAA in the US. Researchers noted that regulations “cannot be taken for granted” and must be monitored to ensure compliance.
"In the end, we concluded that it’s most likely that someone may be producing the CFC-11 that’s escaping to the atmosphere," he said. "We don't know why they might be doing that and if it is being made for some specific purpose, or inadvertently as a side product of some other chemical process." If the source of these new emissions can be identified and controlled soon, the damage to the ozone layer should be minor, Montzka said. If not remedied soon, however, substantial delays in ozone layer recovery could be expected.