Multiannual top-down estimate of HFC-23 emissions in East Asia

Environ Sci Technol. 2015 Apr 7;49(7):4345-53. doi: 10.1021/es505669j. Epub 2015 Mar 30.

Abstract

Trifluoromethane (CHF3, HFC-23), with a 100-year global warming potential (GWP) of 12400, is regulated under the Kyoto Protocol. HFC-23 emissions in East Asia, especially in China, are currently thought to represent the majority of global HFC-23 emissions. This study provides both a bottom-up emission inventory and the multiannual top-down estimate of HFC-23 emissions in East Asia during 2007-2012. The new bottom-up inventory yields improved simulated HFC-23 mixing ratios compared to previous bottom-up inventories. The top-down estimate uses inverse modeling to further improve the model-measurement agreement. Results show that China contributed 94-98% of all HFC-23 emissions in East Asia. Annual a posteriori emissions from China were around 6.3 Gg/yr during the period 2007-2010 after which they increased to 7.1 ± 0.7 Gg/yr in 2011 and 8.8 ± 0.8 Gg/yr in 2012. For the first time, this study also provides a top-down estimate of HFC-23/HCFC-22 (chlorodifluoromethane, CHClF2) coproduction ratios in non-CDM (Clean Development Mechanism) HCFC-22 production plants as well as in all HCFC-22 production plants in China.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Pollutants / analysis*
  • Asia, Eastern
  • China
  • Chlorofluorocarbons, Methane / analysis*
  • Global Warming

Substances

  • Air Pollutants
  • Chlorofluorocarbons, Methane
  • fluorocarbon 22
  • fluoroform