Scientists uncover likely cheating on ozone treaty

  • Scientists uncover likely cheating on ozone treaty

Scientists uncover likely cheating on ozone treaty

"If the emissions were to persist, then we could imagine that healing of the ozone layer, that recovery date, could be delayed by a decade", said Dr Montzka. Though production of CFCs was phased out by the Montreal Protocol, a large reservoir of CFC-11 exists today primarily contained in foam insulation in buildings, and appliances manufactured before the mid-1990s.

The finding seems likely to prompt an worldwide investigation into the mysterious source.

The majority of excess emissions of ozone-damaging CFCs come from East Asia. This was partly because nations had all agreed to ban or phase out CFCs, which are short for "chlorofluorocarbons" but are simply called "ozone-depleting substances", due to an global treaty back in the 1980s called the Montreal Protocol.

Zaelke said he was surprised by the findings, not just because the chemical has always been banned, but also because alternatives already exist, making it hard to imagine what the market for CFC-11 today would be.

According to global CFC-11 levels measured by scientists at NOAA and Cooperative Institute for Research in Environmental Sciences (CIRES), the concentration of the chemical declined at an accelerating rate till 2002, but then, the fall became stagnant for nearly a decade.

Emissions of CFC-11 increased by 25 percent in 2012, despite the fact that the chemical substance is part of a group of pollutants for ozone, which were banned under the Montreal Protocol of 1987.

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.

However, it took many decades for scientists to discover that when CFCs break down in the atmosphere, they release chlorine atoms that are able to rapidly destroy ozone molecules.

"This evidence strongly suggests increased CFC-11 emissions from eastern Asia after 2012".

To put this in perspective, at peak emissions in the 1980s, the world was producing 350,000 tons of CFC-11 each year, before dropping to 54,000 tons per year at the turn of the century.

The chemical is also a powerful greenhouse gas that contributes to global warming.

The UNEP said that is was "critical that we take stock of this science, identify the causes of these emissions and take necessary action". If not remedied soon, however, substantial delays in ozone layer recovery could be expected, Montzka said.

A simple model analysis of our findings suggests an increase in CFC-11 emissions ... despite reported production being close to zero4 since 2006 ...

"This treaty can not afford not to follow its tradition and keep its compliance record", he said.

But in the last few years, it looks like someone has started cheating.

"The increase in emission of CFC-11 appears unrelated to past production", the authors note.

"A timely recovery of the stratospheric ozone layer depends on a sustained decline of CFC-11 concentrations", the wrote.