China’s Hydrofluorocarbon Emissions for 2011–2017 Inferred from Atmospheric Measurements

Hydrofluorocarbons (HFCs) have been widely used in China to replace ozone-depleting substances (ODSs) that must be phased out under the Montreal Protocol. Few studies have reported on HFC emissions in China, especially for recent years and using top-down approaches based on atmospheric measurements. Here we used flask and in situ measurements for nine HFCs from seven sites across China over the period of 2011–2017, and FLEXPART-model-based Bayesian inverse modeling, to estimate HFC emission magnitudes and changes in China. We found that emissions of HFC-32 (CH2F2), HFC-125 (CHF2CF3), HFC-134a (CH2FCF3), HFC-227ea (CF3CHFCF3), and HFC-245fa (CHF2CH2CF3) have been increasing fast over this period while emissions of HFC-143a (CH3CF3), HFC-152a (CH3CHF2), HFC-236fa (CF3CH2CF3), and HFC-365mfc (CH3CF2CH2CF3) have been relatively stable. Total CO2-equivalent emissions of the nine HFCs increased from ∼60 Tg year–1 in 2011 to ∼100 Tg year–1 in 2017. Among these nine HFCs, HFC-134a (39%) and HFC-125 (35%) make the largest contributors to the national total HFC CO2-equivalent emissions. Cumulative contributions from China's HFC emissions to the global total HFC mole fractions and their related radiative forcing increased from 1.0% in 2005 to 10.7% in 2017. Upon comparison of global emissions with the sum of emissions from China and developed countries, an increasing difference is observed over recent years, which points to substantial additional HFC emissions from other developing countries under the Kyoto Protocol.