A new method of hotspot analysis on the management of CO2 and air pollutants, a case study in Guangzhou city, China

Emission inventory plays an important role in designing effective emission control strategies. Currently, there is unbalanced development of CO2 and air pollutant emission inventories in China and the spatial information of both cannot be obtained simultaneously, which prevents a collaborative control strategy. In this study, we developed a unified emission inventory including both CO2 and air pollutants, then utilized spatial mapping methods to identify the co-hotspots of both CO2 and air pollutants at a high spatial resolution (1 x 1 km2). We applied Guangzhou city as a case study to illustrate the method. The results showed that CO2 and air pollutants were mainly emitted from the stationary combustion sector and the trans-portation sector. These two sectors contributed 95 %, 67 %, and 93 % to total CO2, SO2, and NOx emissions, respectively. Up to 86 %, 86 %, 66 %, and 72 % of total CO2, SO2, NOx, and PM2.5 emissions were attributed to the top 10 % emission grids with 1 x 1 km2 resolution. However, our results showed high emission grids were not surrounded by other high emissions grids for all types of emissions analyzed in this study. The co-hotspot analysis enables accurate identification of high -emission grids, which helps environment managers to prioritize resource allocation when designing control strategies. Our study underscores the importance of managing CO2 and air pollutants simultaneously at the city level.

Automated summary

Emission inventory is crucial for designing effective emission control strategies. However, there is an imbalance in the development of CO2 and air pollutant emission inventories in China, hindering collaborative control strategies. This study developed a unified emission inventory including both CO2 and air pollutants, and used spatial mapping methods to identify co-hotspots at a high spatial resolution. The results showed that the stationary combustion and transportation sectors were the major emitters, and the top 10% emission grids contributed the majority of the emissions.