Sustained Increases in Hydrofluorocarbon Emissions from China and Implications for Global Emissions

Area of Science:

• Atmospheric chemistry and climate science
• Environmental monitoring and policy

Background:

• Hydrofluorocarbons (HFCs) are potent greenhouse gases used as substitutes for ozone-depleting substances.
• China is a significant region for HFC emissions, but precise quantification remains challenging.
• The Montreal Protocol regulates HFCs, necessitating accurate emission data for effective control.

Purpose of the Study:

• To quantify HFC emissions in northern China using novel high-frequency in situ observations.
• To reveal the spatial distribution of HFC emissions across Chinese provinces.
• To assess the trend and global significance of China's HFC emissions.

Main Methods:

• Deployment of high-frequency in situ monitoring at the Changdao (CHD) station for HFC-125, HFC-134a, and HFC-143a.
• Application of an inverse modeling approach combining CHD observations with other data.
• Calculation of CO2-equivalent emissions and comparison with global averages.

Main Results:

• Distinct spatial patterns of HFC emissions in northern China were identified.
• Combined CO2-equivalent emissions of HFCs in China surged from 7.1 Mt in 2005 to 206.4 Mt in 2022.
• China's per area, per capita, and per GDP HFC emissions surpassed global averages.

Conclusions:

• High-frequency observations are critical for accurate HFC emission assessment in China.
• The findings provide crucial data for prioritizing HFC control measures across Chinese provinces.
• China's escalating HFC emissions pose a significant challenge to global climate mitigation efforts under the Montreal Protocol.