Rapid increase in dichloromethane emissions from China inferred through atmospheric observations

Abstract

<jats:title>Abstract</jats:title><jats:p>With the successful implementation of the Montreal Protocol on Substances that Deplete the Ozone Layer, the atmospheric abundance of ozone-depleting substances continues to decrease slowly and the Antarctic ozone hole is showing signs of recovery. However, growing emissions of unregulated short-lived anthropogenic chlorocarbons are offsetting some of these gains. Here, we report an increase in emissions from China of the industrially produced chlorocarbon, dichloromethane (CH<jats:sub>2</jats:sub>Cl<jats:sub>2</jats:sub>). The emissions grew from 231 (213–245) Gg yr<jats:sup>−1</jats:sup> in 2011 to 628 (599–658) Gg yr<jats:sup>−1</jats:sup> in 2019, with an average annual increase of 13 (12–15) %, primarily from eastern China. The overall increase in CH<jats:sub>2</jats:sub>Cl<jats:sub>2</jats:sub> emissions from China has the same magnitude as the global emission rise of 354 (281−427) Gg yr<jats:sup>−1</jats:sup> over the same period. If global CH<jats:sub>2</jats:sub>Cl<jats:sub>2</jats:sub> emissions remain at 2019 levels, they could lead to a delay in Antarctic ozone recovery of around 5 years compared to a scenario with no CH<jats:sub>2</jats:sub>Cl<jats:sub>2</jats:sub> emissions.</jats:p>