The assessment, containing research from 300 scientists, comes from the United Nations Environment Program (UNEP), and the World Meteorological Organization (WMO).
Since 1989, the Montreal Protocol and associated agreements have restricted ozone depleting substances across the world. Reductions will have prevented two million cases of skin cancer annually by 2030, and averted damage to human eyes and immune systems, according to the UNEP. A spin-off from the protocol is a decline in greenhouse gas emissions. In 1987, ozone-depleting substances contributed about ten gigatonnes of CO2-equivalent emissions per year. The protocol cut these by more than 90 per cent. However, the assessment cautions that the rapid increase in certain substitutes, which are also greenhouse gases, has the potential to undermine any gains.
‘There are positive indications that the ozone layer is on track to recovery,’ said UN Under-Secretary-General and UNEP Director Achim Steiner noting that the report expects the layer to recover to 1980 benchmark levels before the middle of the century in mid-latitudes and the Arctic, but somewhat later in the Antarctic.
