Impacts of regional emission reduction and global climate change on air quality and temperature to attain carbon neutrality in China

Abstract

Future air quality and temperature are major concerns worldwide, especially in East Asia, leading to carbon neutrality targets. China is committed to achieving carbon neutrality by 2060. This study evaluated regional emission reduction targets and global climate change impacts in China. We investigated changes to air quality and temperature in China using the coupled regional climate-ecology model RegCM-Chem-YIBs. The Ambitious-Pollution-Neutral-Goals scenario from the Dynamic Projection model for Emissions in China (DPEC) database was chosen as the future emission reduction pathway in China. Representative concentration pathway (RCP) climate scenarios were used to represent one possibility for future global climate change. The results showed that annual average PM2.5 and O3 concentrations in China could meet World Health Organization (WHO) guidelines if the carbon neutral reduction pathway is followed. Emission reduction is far more effective than climate change in improving air quality. PM2.5 and O3 concentrations in 2060 will decline to 2.6 and 63.0 μg m−3, respectively, under stringent emission reduction policies. Both carbon reduction and photosynthesis of vegetation promoted by global warming will reduce CO2 concentrations by at least 8 ppm in 2060. Global climate change will heat up the entire country by at least 1 K. Regional emission reduction will diminish the cooling effect of particulate matter, resulting in slight warming, which would slow progress in global warming control. This study shows that regional emission reduction is the main factor affecting future air quality, whereas global climate change is the primary driver of future increases in air temperature. The emission reduction policy, which is designed to achieve carbon neutrality in China, is sufficient to mitigate air pollution, and generate additional health benefits; however, it will contribute to higher air temperature in some areas. Therefore, mitigating rising temperatures requires global efforts and a more rational pathway to reduce emissions.