Emissions of a banned, ozone-depleting chemical are on the rise, a group of scientists reported Wednesday, suggesting someone may be secretly manufacturing the pollutant in violation of an international accord.
Emissions of CFC-11 have climbed 25 per cent since 2012, despite the chemical being part of a group of ozone pollutants that were phased out under the 1987 Montreal Protocol.
“I’ve been making these measurements for more than 30 years and this is the most surprising thing I’ve seen,” said Stephen Montzka, a scientist with the National Oceanic and Atmospheric Administration who led the work. “I was astounded by it really.”
It’s a distressing result for what’s widely seen as a global environmental success story, in which nations — alarmed by a growing “ozone hole” — collectively took action to phase out chlorofluorocarbons.
The finding seems likely to prompt an international investigation into the mysterious source.
Officially, production of CFC-11 is supposed to be at or near zero — at least, that is what countries have been telling the United Nations body that monitors and enforces the Protocol. But with emissions on the rise, scientists suspect someone is making the chemical in defiance of the ban.
“Somebody’s cheating,” said Durwood Zaelke, founder of the Institute for Governance and Sustainable Development and an expert on the Montreal Protocol, in a comment on the new research. “There’s some slight possibility there’s an unintentional release, but . . . they make it clear there’s strong evidence this is actually being produced.”
But for now, the scientists don’t know exactly who, or where, that person would be. A U.S. observatory in Hawaii found CFC-11 mixed in with other gases that were characteristic of a source coming from somewhere in east Asia, but scientists could not narrow the source down any further.
Zaelke said he was surprised by the findings, not just because the chemical has long been banned, but also because alternatives already exist, making it hard to imagine what the market for CFC-11 today would be.
The research was led by researchers with the U.S. National Oceanic and Atmospheric Administration with help from scientists in the Netherlands and the United Kingdom. Their results were published in the journal Nature.