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Lunt, MF, Park S, Li S, Henne S, Manning AJ, Ganesan AL, Simpson IJ, Blake DR, Liang Q, O'Doherty S, Harth CM, Mühle J, Salameh PK, Weiss RF, Krummel PB, Fraser PJ, Prinn RG, Reimann S, Rigby M.  2018.  Continued emissions of the ozone-depleting substance carbon tetrachloride from Eastern Asia. Geophysical Research Letters. : Wiley-Blackwell   10.1029/2018GL079500   Abstract

Abstract Carbon tetrachloride (CCl4) is an ozone-depleting substance, accounting for about 10% of the chlorine in the troposphere. Under the terms of the Montreal Protocol, its production for dispersive uses was banned from 2010. In this work we show that, despite the controls on production being introduced, CCl4 emissions from the eastern part of China did not decline between 2009 and 2016. This finding is in contrast to a recent bottom-up estimate, which predicted a significant decrease in emissions after the introduction of production controls. We find eastern Asian emissions of CCl4 to be 16 (9?24) Gg/year on average between 2009 and 2016, with the primary source regions being in eastern China. The spatial distribution of emissions that we derive suggests that the source distribution of CCl4 in China changed during the 8-year study period, indicating a new source or sources of emissions from China's Shandong province after 2012.

Rhew, RC, Miller BR, Weiss RF.  2008.  Chloroform, carbon tetrachloride and methyl chloroform fluxes in southern California ecosystems. Atmospheric Environment. 42:7135-7140.   10.1016/j.atmosenv.2008.05.038   AbstractWebsite

Chloroform (CHCl3), carbon tetrachloride (CCl4), and methyl chloroform (CH3CCl3) are important carriers of chlorine to the stratosphere and account for an estimated 159 of the total organic chlorine in the troposphere, roughly equivalent to chlorine load due to methyl chloride (CH3Cl). The tropospheric burden of chlorine has declined since 1994, largely due to the restriction of CH3CCl3 and CCl4 use as specified by the Montreal Protocol. However, few field studies have been conducted on the terrestrial-atmosphere exchange of these chlorinated hydrocarbons, leading to uncertainties about the natural cycling of these trace gases. This work shows the results of 75 flux measurements conducted in a variety of southern California ecosystems, including coast sagebrush, chamise chaparral, creosote bush scrub, shoreline, and coastal salt marsh. We find no evidence of a significant soil sink in these ecosystems but rather a small net source of CHCl3 and possibly CCl4. (c) 2008 Elsevier Ltd. All rights reserved.