Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK.
School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK.
Nat Commun. 2017 Jun 27;8:15962. doi: 10.1038/ncomms15962.
It is well established that anthropogenic chlorine-containing chemicals contribute to ozone layer depletion. The successful implementation of the Montreal Protocol has led to reductions in the atmospheric concentration of many ozone-depleting gases, such as chlorofluorocarbons. As a consequence, stratospheric chlorine levels are declining and ozone is projected to return to levels observed pre-1980 later this century. However, recent observations show the atmospheric concentration of dichloromethane-an ozone-depleting gas not controlled by the Montreal Protocol-is increasing rapidly. Using atmospheric model simulations, we show that although currently modest, the impact of dichloromethane on ozone has increased markedly in recent years and if these increases continue into the future, the return of Antarctic ozone to pre-1980 levels could be substantially delayed. Sustained growth in dichloromethane would therefore offset some of the gains achieved by the Montreal Protocol, further delaying recovery of Earth's ozone layer.
众所周知，人为含氯化学物质会导致臭氧层消耗。《蒙特利尔议定书》的成功实施导致许多消耗臭氧层气体（如氯氟烃）在大气中的浓度降低。因此，平流层中的氯含量正在下降，预计本世纪晚些时候臭氧将恢复到 1980 年以前的水平。然而，最近的观测显示，不受《蒙特利尔议定书》控制的消耗臭氧层气体二氯甲烷在大气中的浓度正在迅速增加。利用大气模式模拟，我们表明，尽管目前规模较小，但近年来二氯甲烷对臭氧的影响显著增加，如果这些增加持续到未来，南极臭氧恢复到 1980 年以前的水平可能会大大延迟。二氯甲烷的持续增长将抵消《蒙特利尔议定书》取得的部分成果，进一步延迟地球臭氧层的恢复。
