CH2Cl2 emissions from China inferred from atmospheric observations

The importance of dichloromethane (CH2Cl2) on stratospheric ozone has intensified in recent years, with China suspected to be a contributor to global emissions. However, China’s post-2019 emissions remain poorly constrained. Here we show that CH2Cl2 emissions in China were 931 ± 107 gigagram per year (Gg yr−1) in 2024, an increase of 303 ± 111 Gg yr−1 relative to 2019. These values indicate a higher average growth rate of 67.0 ± 15.2 Gg yr−2 during 2019–2024, compared with the previously reported 42.0 ± 8.1 Gg yr−2 during 2011–2019, despite some measures restricting CH2Cl2 use in China since 2020. Moreover, the proportion of China’s CH2Cl2 emissions to global emissions rose from 2011 to 2024. These findings highlight the importance of continued monitoring and mitigating CH2Cl2 emissions in the context of ozone layer recovery. Measurements across China reveal that emissions of dichloromethane, a substance with a growing impact on ozone-layer recovery, rose faster during 2021–2024 than during 2011–2019, despite measures introduced since 2020 to curb its use.