The ozone layer has made an impressive recovery in the last 30 years, but that has never been a foolproof plan.
The culprit who is generating this pollutant is still unknown and at large.
“We were shocked, no doubt,” says Stephen Montzka, a scientist with the National Oceanic and Atmospheric Administration and lead author of the new study.
“We couldn’t understand how on Earth emissions would be increasing when production had been zero for so long.”
The chemical, CFC-11, is part of a class of substances called chlorofluorocarbons (CFCs) once hailed as a pinnacle of 20th century industrial chemistry.
The world came together in 1987 to sign the Montreal Protocol, a pact that effectively banned all ozone-depleting substances, including CFCs.
While CFC-11 is no more dangerous to the ozone layer than other chlorine-containing chemical species, it’s the second-most abundant CFC. »