Estimate of Hydrofluorocarbon Emissions for 2012–16 in the Yangtze River Delta, China

Hydrofluorocarbons(HFCs)have been widely used in China as substitutes for ozone-depleting substances,the production and use of which are being phased out under the Montreal Protocol.China is a major consumer of HFCs around the world,with its HFC emissions in CO2-equivalent contributing to about 18%of the global emissions for the period2012-16.Three methods are widely used to estimate the emissions of HFCs-namely,the bottom-up method,top-down method and tracer ratio method.In this study,the tracer ratio method was adopted to estimate HFC emissions in the Yangtze River Delta(YRD),using CO as a tracer.The YRD region might make a significant contribution to Chinese totals owing to its rapid economic growth.Weekly flask measurements for ten HFCs(HFC-23,HFC-32,HFC-125,HFC-134 a,HFC-143 a,HFC-152 a,HFC-227 ea,HFC-236 fa,HFC-245 fa and HFC-365 mfc)were conducted at Lin’an Regional Background Station in the YRD over the period 2012-16,and the HFC emissions were 2.4±1.4 Gg yr-1 for HFC-23,2.8±1.2 Gg yr-1 for HFC-32,2.2±1.2 Gg yr-1 for HFC-125,4.8±4.8 Gg yr-1 for HFC-134 a,0.9±0.6 Gg yr-1 for HFC-152 a,0.3±0.3 Gg yr-1 for HFC-227 ea and 0.3±0.2 Gg yr-1 for HFC-245 fa.The YRD total HFC emissions reached 53 Gg CO2-e yr-1,contributing 34%of the national total.The per capita HFC CO2-equivalent emissions rate was 240 kg yr-1,while the values of per unit area emissions and per million GDP emissions reached 150 Mg km-2yr-1 and 3500 kg yr-1(million CNY GDP)-1,which were much higher than national or global levels.