19 December 2014: A report by nearly 300 scientists from 36 countries has concluded that ozone layer recovery will occur more rapidly if eliminating the production of the ozone-depleting substance (ODS) hydrochlorofluorocarbons (HCFCs), and managing other remaining ODSs, are fast-tracked. ‘Scientific Assessment of Ozone Depletion: 2014′ finds that phasing out the small remaining uses of ODSs, which are currently exempted from phase-outs, would hasten ozone recovery by about 11 years.

The Assessment – a summary of which was issued in September 2014 – describes the first signs of an upward trend in ozone recovery, noting the ozone layer is on track to recovery to 1980 levels by mid-century, due to actions taken to phase out ODSs. It projects that atmospheric ODS amounts will continue to decline through the 21st century, assuming continued compliance with the Montreal Protocol on Substances that Deplete the Ozone Layer. In addition, since ODSs are also powerful global warming gases, the Protocol has led to climate change mitigation and a reduction of more than 135 billion tonnes in carbon dioxide (CO2) equivalent emissions.

However, the report warns, the climate benefits of the Montreal Protocol could be offset by projected increases in emissions of hydrofluorocarbons (HFCs), which are currently being used to replace ODSs. Replacing high global warming potential (GWP) HFCs with low-GWP HFCs and other alternatives could reduce or avoid their climate impacts.

The report, which was presented by the Scientific Assessment Panel (SAP) of the Montreal Protocol during the 26th Meeting of the Parties (MOP 26), in November 2014, is published by the UN Environment Programme (UNEP) and the World Meteorological Organization (WMO). The SAP assesses the state of the depletion of the ozone layer and relevant atmospheric science issues every four years, and provides information to Montreal Protocol Parties for their use in ozone protection activities. [UNEP Press Release] [WMO Press Release] [Publication: Scientific Assessment of Ozone Depletion: 2014] [Publication: Assessment for Decision Makers] [IISD RS Story on Publication of Assessment for Decision Makers] [IISD RS Coverage of MOP 26]