China's greenhouse gas budget during 2000-2023

Area of Science:

• Environmental Science
• Climate Science
• Atmospheric Chemistry

Background:

• Greenhouse gas (GHG) emissions are a major global concern.
• China is actively working to reduce GHG emissions and enhance land sinks.
• Accurate GHG flux monitoring is vital for China's climate change mitigation efforts.

Purpose of the Study:

• To estimate long-term GHG sources and sinks in China from 2000-2023.
• To develop an updated China GHG Budget dataset (CNGHG).
• To provide sector-specific and regional GHG flux data for emission reduction strategies.

Main Methods:

• Utilized emission factor methods, process-based models, atmospheric inversions, and data-driven models.
• Estimated GHG fluxes from all anthropogenic and natural sectors.
• Compiled a comprehensive China GHG Budget dataset.

Main Results:

• Total gross GHG emissions in China tripled from 5.0 Gt CO2-eq yr-1 in 2000 to 14.3 Gt CO2-eq yr-1 in 2023.
• CO2, CH4, and N2O constituted 81.8%, 12.7%, and 5.5% of emissions in 2023, respectively.
• Terrestrial ecosystems acted as a net CO2 sink, absorbing 1.0 Gt CO2 yr-1 between 2012-2021.

Conclusions:

• The energy sector is the primary source of CO2 emissions.
• Agriculture, forestry, and other land use are major sources of CH4 and N2O.
• The study provides crucial data for targeted GHG emission reductions in China.