Strategy for coordinating near-term PM_2.5, ozone, and CO₂ mitigation in China

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Climate Policy

Background:

• China faces the dual challenge of improving air quality (PM2.5 and O3) and addressing climate change.
• Existing studies often focus on controlling PM2.5 and O3 together or on CO2 reduction synergy with PM2.5, neglecting a comprehensive approach for all three.

Purpose of the Study:

• To evaluate various combinations of clean-air and climate policies in China.
• To identify effective strategies for the "triple control" of PM2.5, O3, and CO2.

Main Methods:

• Utilized an integrated framework combining emission projection models, optimization methods, chemical transport modeling, and cost-benefit analysis.
• Assessed the impact of different policy combinations on air quality and climate targets.

Main Results:

• Current clean-air policies effectively control PM2.5 but have limited impact on O3.
• End-of-pipe measures for NOx and VOCs can co-control PM2.5 and O3 but are weather-dependent.
• Climate policies alone offer minimal air quality improvements, especially for O3.
• A combined strategy is necessary for "triple control".

Conclusions:

• Stringent clean-air actions coupled with ambitious climate mitigation are crucial for China's environmental goals.
• The integrated strategy can significantly reduce PM2.5 and O3 concentrations by 2030.
• This approach offers substantial economic benefits and informs future environmental policy in China and other developing regions.