Substantial increase in perfluorocarbons CF₄ (PFC-14) and C₂F₆ (PFC-116) emissions in China

Area of Science:

• Atmospheric Chemistry
• Environmental Science
• Climate Change Research

Background:

• Perfluorocarbons tetrafluoromethane (CF4) and hexafluoroethane (C2F6) are potent greenhouse gases with long atmospheric lifetimes.
• Their global warming potentials are thousands of times greater than CO2.

Purpose of the Study:

• To quantify CF4 and C2F6 emissions in China using atmospheric observations.
• To identify the primary industrial sources and spatial distribution of these emissions.
• To compare Chinese emissions with global emission trends.

Main Methods:

• Utilized a network of long-term atmospheric observations in China.
• Employed an inverse modeling approach (top-down method) to determine emissions.
• Validated findings against national bottom-up inventory data.

Main Results:

• CF4 emissions in China rose by ~78% from 4.7 Gg y-1 in 2012 to 8.3 Gg y-1 in 2021.
• C2F6 emissions in China increased by ~78% from 0.74 Gg y-1 in 2011 to 1.32 Gg y-1 in 2021.
• Significant emissions were detected in western China, linked to the aluminum and semiconductor industries.

Conclusions:

• China's CF4 and C2F6 emissions have substantially increased, contributing significantly to global totals.
• The aluminum industry is the likely dominant source of CF4, with both aluminum and semiconductor industries contributing to C2F6 emissions.
• Atmospheric data provide crucial insights into emission magnitudes, spatial distribution, and sources beyond national inventories.