Bottom-up anthropogenic dichloromethane emission estimates from China for the period 2005–2016 and predictions of future emissions

Abstract

It has been shown that the short-lived halogenated hydrocarbons, such as dichloromethane (DCM), which are not regulated by the Montreal Protocol, have the potential to impact stratospheric ozone. DCM with increasing atmospheric mixing ratios in recent years, is widely used in solvent, foam-blowing and methyl fluoride production sectors in China, which is a large producer as well as consumer of DCM. This study develops a comprehensive emission inventory of anthropogenic DCM in China using a bottom-up method based on the industrial consumption of DCM in China from 2005 to 2016 and makes a projection to 2030. The inventory considered solvent use, polyurethane (PU) foam manufacturing, the chemical industry, and other end uses. Anthropogenic emissions of DCM increased from 101 (80–122) Gg/yr to 318 (254–384) Gg/yr between 2005 and 2016, a increase of 215% over the last 11 years. Solvent use and the manufacture of PU foam agents are the major contributors to total DCM emissions. Under a business as usual (BAU) scenario future Chinese emissions of DCM are predicted to increase to 708 (588–831) Gg/yr by 2030, more than twice the emission IHS, 2016. Chinese emission account for approximately 25%–37% of the 515 Gg/yr estimates by the WMO as average annual global emissions in 2008.