Interaction Patterns between Climate Action and Air Cleaning in China: A Two-Way Evaluation Based on an Ensemble Learning Approach

Abstract

China will attempt to achieve its simultaneous goals in 2060, whereby carbon neutrality will be accomplished and the PM2.5 (fine particulate matter) level is expected to remain below 10 μg/m3. Identifying interaction patterns between air cleaning and climate action represents an important step to obtain cobenefits. Here, we used a random sampling strategy through the combination of chemical transport modeling and machine learning approach to capture the interaction effects from two perspectives in which the driving forces of both climate action and air cleaning measures were compared. We revealed that climate action where carbon emissions were decreased to 1.9 Bt (billion tons) could lead to a PM2.5 level of 12.4 μg/m3 (95% CI (confidence interval): 10.2–14.6 μg/m3) in 2060, while air cleaning could force carbon emissions to reach 1.93 Bt (95% CI: 0.79–3.19 Bt) to achieve net carbon neutrality based on the potential carbon sinks in 2060. Additional controls targeting primary PM2.5, ammonia, and volatile organic compounds were required as supplements to overcome the partial lack of climate action. Our study provides novel insights into the cobenefits of air-quality improvement and climate change mitigation, indicating that the effect of air cleaning on the simultaneous goals might have been underestimated before.

Integrated Benefits of Synergistically Reducing Air Pollutants and Carbon Dioxide in China

“…Various measures demonstrate distinct strengths in promoting air quality benefits and CO 2 reduction benefits (Figure ). Historically, measures for clean air and climate change mitigation were often discussed separately. , However, in the upcoming era of synergistically reducing air pollution and carbon, an integrated approach to implementing measures is crucial for sustained benefit enhancement and concurrent realization of multiple reduction goals. Indexes introduced in this study can serve as valuable tools for identifying impactful measures.…”

Cost-Effectiveness of NOX and VOC Co-operative Controls for PM2.5 and O3 Mitigation in the Context of China’s Carbon Neutrality

“…However, carbon neutrality can also lead to partial reductions in AVOCs, and thus, additional benefits from co-operative controls are fewer than our assessment suggests. Since PM 2.5 -related deaths account for the lion’s share of the total air pollution-related deaths, reductions in NH 3 or primary PM 2.5 emissions, which are more effective for PM 2.5 abatement, , might generate more significant health benefits than AVOCs associated with co-operative controls.…”

“…Three underlying reasons are as follows: (1) Most proposed co-operative strategies might be unviable, as future reductions in NO X will be more substantial than those in AVOCs due to carbon neutrality. This occurs because carbon neutrality associated with energy transitions can directly curtail pollutants from fossil fuel combustion, such as NO X , while most AVOCs originating from solvent use need additional control measures. − (2) Despite NO X disbenefits, O 3 concentrations can ultimately decrease to low levels via constant NO X reductions . That is, both PM 2.5 and O 3 pollution will be mitigated by carbon neutrality regardless of co-operative controls.…”