"These considerations suggest that the increased CFC-11 emissions arise from new production not reported to UNEP's Ozone Secretariat, which is inconsistent with the agreed phase-out of CFC production in the Montreal Protocol by 2010", the researchers wrote.
The finding seems likely to prompt an global investigation into the mysterious source.
Banned chemicals which can cause holes in the ozone layer are on the rise, according to a new report, and no one knows who the culprit is. Since 2007, there has been essentially zero reported production of CFC-11, the second most damaging of all CFCs. Once widely used as a foaming agent, production of CFC-11 was phased out by the Montreal Protocol in 2010.
The ozone layer in the stratosphere, 10-to-40 kilometers above Earth's surface, protects life on the planet from deadly ultraviolet radiation.More news: US Senates get enough votes to progress on net neutrality
More news: 'Yanny' or 'Laurel': The recording that is splitting the internet in half
More news: Top lawyer at Novartis to step down amid Michael Cohen scandal
Paul Young, at Lancaster University, UK, said: "The Montreal Protocol has been rightly hailed as our most successful worldwide environmental treaty, so the suggestion that there are possibly continued, unreported emissions of CFCs is certainly troubling and needs further investigation". Movement of gases around the atmosphere, the destruction of buildings harboring CFCs from the 1970s and the failure to capture the chemical during the production of other chemicals could all lead to a rise in CFC-11, but not almost enough to explain the results.
Montzka said the most likely scenario is someone is producing new CFC-11. This means that the total concentration of ozone-depleting chemicals, overall, is still decreasing in the atmosphere.
However, a new study shows that not all is as well as we thought: someone has been cheating on the Montreal Protocol by producing new ozone-depleting chemicals on an industrial scale. "It is critical that we take stock of this science, identify the causes of these emissions and take necessary action", he said.
"The analysis of these extremely precise and accurate atmospheric measurements is an excellent example of the vigilance needed to ensure continued compliance with provisions of the Montreal Protocol and protection of the Earth's ozone layer", Fahey said. This insults everybody who's worked on this for the last 30 years. However, starting in 2013, emissions of CFC11 have been rising again, according to a study by a team at the National Oceanic and Atmospheric Administration, published in Nature magazine.
The Montreal Protocol was created to protect the stratospheric ozone layer by enabling reductions in the abundance of ozone-depleting substances such as CFC chemicals in the atmosphere. This, in turn, will delay the ozone layer's recovery, and in the meantime leave it more vulnerable to other threats. When the ozone layer is weakened, more UV rays can get through and affect humans, making them prone to skin cancer, cataracts and other diseases.