The depletion of stratospheric ozone, driven primarily by the presence of chlorine and bromine in the stratosphere, is a significant health risk to human and animal life. The ozone layer has started to recover following the Montreal Protocol of 1987 , which banned many ozone-depleting substances, but full recovery is not expected until around 2070 .
As of 2016, world emissions of ozone-depleting substances are estimated as follows. Evidence suggests the unreported increase in CFC-11 emissions, which is illegal under the Montreal Protocol, is coming from Eastern China .
Based on a social cost of CFC-11 of $618 (2020 dollars) reported in 1992 , current world ozone-depleting emissions from human activity inflict $86-199 billion of damages per year. Separately, the Montreal Protocol has been estimated to prevent $51 billion (2020 dollars) in damages per year from 1987 to 2060 to human health, agriculture, fisheries, and materials .
 Goddard Space Flight Center. "NASA Ozone Watch". National Aeronautics and Space Administration. Accessed April 27, 2020.
 Rigby, M. et al. "Increase in CFC-11 emissions from eastern China based on atmospheric observations". Nature 569, pp. 546–550. May 2019.
 United Nations Environment Programme. "The Montreal Protocol and the Green Economy: Assessing the contributions and co-benefits of a Multilateral Environmental Agreement". 2012.
 WMO (World Meteorological Organization). Scientific Assessment of Ozone Depletion: 2018. Global Ozone Research and Monitoring Project–Report No. 58, 588 pp., Geneva, Switzerland. 2018.