An integrated view of correlated emissions of greenhouse gases and air pollutants in China.

BACKGROUND

Air pollution in China has raised great concerns due to its adverse effects on air quality, human health, and climate. Emissions of air pollutants (APs) are inherently linked with CO emissions through fossil-energy consumption. Knowledge of the characteristics of APs and CO emissions and their relationships is fundamentally important in the pursuit of co-benefits in addressing air quality and climate issues in China. However, the linkages and interactions between APs and CO in China are not well understood.

RESULTS

Here, we conducted an ensemble study of six bottom-up inventories to identify the underlying drivers of APs and CO emissions growth and to explore their linkages in China. The results showed that, during 1980-2015, the power and industry sectors contributed 61-79% to China's overall emissions of CO, NO, and SO. In addition, the residential and industrial sectors were large emitters (77-85%) of PM, PM, CO, BC, and OC. The emissions of CH, NO and NH were dominated by the agriculture sector (46-82%) during 1980-2015, while the share of CH emissions in the energy sector increased since 2010. During 1980-2015, APs and greenhouse gases (GHGs) emissions from residential sources generally decreased over time, while the transportation sector increased its impact on recent emissions, particularly for NO and NMVOC. Since implementation of stringent pollution control measures and accompanying technological improvements in 2013, China has effectively limited pollution emissions (e.g., growth rates of -10% per year for PM and -20% for SO) and slowed down the increasing trend of carbon emissions from the power and industrial sectors. We also found that areas with high emissions of CO, NO, NMVOC, and SO also emitted large amounts of CO, which demonstrates the possible common sources of APs and GHGs. Moreover, we found significant correlations between CO and APs (e.g., NO, CO, SO, and PM) emissions in the top 5% high-emitting grid cells, with more than 60% common grid cells during 2010-2015.

CONCLUSIONS

We found significant correlation in spatial and temporal aspects for CO, and NO, CO, SO, and PM emissions in China. We targeted sectorial and spatial APs and GHGs emission hot-spots, which help for management and policy-making of collaborative reductions of them. This comprehensive analysis over 6 datasets improves our understanding of APs and GHGs emissions in China during the period of rapid industrialization from 1980 to 2015. This study helps elucidate the linkages between APs and CO from an integrated perspective, and provides insights for future synergistic emissions reduction.