Rapid increase in dichloromethane emissions from China inferred through atmospheric observations

An, Minde and Western, Luke M. and Say, Daniel and Chen, Liqu and Claxton, Tom and Ganesan, Anita L. and Hossaini, Ryan and Krummel, Paul B. and Manning, Alistair J. and Mühle, Jens and O’Doherty, Simon and Prinn, Ronald G. and Weiss, Ray F. and Young, Dickon and Hu, Jianxin and Yao, Bo and Rigby, Matthew (2021) Rapid increase in dichloromethane emissions from China inferred through atmospheric observations. Nature Communications, 12 (1). ISSN 2041-1723

Abstract

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 (CH2Cl2). The emissions grew from 231 (213–245) Gg yr−1 in 2011 to 628 (599–658) Gg yr−1 in 2019, with an average annual increase of 13 (12–15) %, primarily from eastern China. The overall increase in CH2Cl2 emissions from China has the same magnitude as the global emission rise of 354 (281−427) Gg yr−1 over the same period. If global CH2Cl2 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 CH2Cl2 emissions.