Anthropogenic emissions of trichloromethane (chloroform, CHCl₃) and chlorodifluoromethane (HCFC‐22): Reactive Chlorine Emissions Inventory

Abstract

Anthropogenic emissions of trichloromethane (CHCl 3 , chloroform) in 1990 have been estimated with a variety of methods specific to the source category. The largest source category for CHCl 3 was found to be pulp and paper manufacturing, responsible for an estimated 30±8 Gg yr −1 reactive chlorine in the form of CHCl 3 . Water treatment of various types was estimated to contribute another 19±12 Gg. Manufacturing facilities of products other than pulp or paper and other relatively minor sources were estimated to emit an additional 13±5 Gg yr −1 , for a total of 62±25 Gg yr −1 reactive chlorine in the form of CHCl 3 . The global flux of chlorodifluoromethane (HCFC‐22) is well characterized from industrial and regulatory data to have been 195 Gg in 1990, equivalent to 80±0.6 Gg yr −1 as active chlorine. The fluxes of reactive chlorine from CHCl 3 and HCFC‐22, distributed globally in a 1° latitude times 1° longitude grid, revealed areas highest in emissions.