A synthesis inversion to constrain global emissions of two very short lived chlorocarbons: Dichloromethane, and perchloroethylene

In absolute terms, Asian CH(2)Cl(2)emissions increased annually by 51 Gg yr(-1)over the study period, while European and North American emissions declined, indicating a continental-scale shift in emission distribution since the mid-2000s. For C2Cl4, we estimate a decrease in global emissions from 141 +/- 14 Gg yr(-1)in 2007 to 106 +/- 12 Gg yr(-1)in 2017. The time-varying posterior emissions offer significant improvements over the prior.

Utilizing the posterior emissions leads to modeled tropospheric CH(2)Cl(2)and C(2)Cl(4)abundances and trends in good agreement to those observed (including independent observations to the inversion). A shorter C(2)Cl(4)lifetime, from including an uncertain Cl sink, leads to larger global C(2)Cl(4)emissions by a factor of similar to 1.5, which in some places improves model-measurement agreement. The sensitivity of our findings to assumptions in the inversion procedure, including CH(2)Cl(2)oceanic emissions, is discussed.