Reply on RC3

Abstract

<strong class="journal-contentHeaderColor">Abstract.</strong> China is facing the challenge of synergistic reducing air pollutants and CO₂ emissions in the coming decades. The coupled emission inventory of air pollutants and CO₂ is a prerequisite to designing the synergetic emission reduction strategy. This study compiled China&rsquo;s emission inventory of air pollutants and CO₂ during 2005&ndash;2021 (ABaCAS-EI v2.0 dataset) based on a unified emission source framework and uniformed activity. The mitigation policies have decoupled the emissions of air pollutants and CO₂ with economic development in China since 2013. In the context of growing activity levels, energy structure adjustment and energy &amp; material saving brought a 7 % drop in the average annual growth rate of CO₂ emissions after 2011; on the basis, end-of-pipe control contributed 51 %&ndash;98 % of air pollutants emission reductions after 2013. Sectors of industrial boilers and residential fossil combustion, and seven provinces (including Beijing, Tianjin, Shanghai, Jilin, Henan, Sichuan, and Qinghai) have achieved emission reductions of both air pollutants and CO₂ during 2013&ndash;2021. The declining trends in both sectoral and regional emission ratios of air pollutants to CO₂ indicated that the potential for synergistic emission reduction in China has declined from 2013 to 2021. The emission ratios in 2021 show that the residential fossil fuel combustion, iron and steel industry, and transportation have relatively higher co-benefits of SO₂, PM_2.5, NOx, and VOCs emission reductions when reducing CO₂ emissions. Most of the cities with higher potential to synergistically reduce NOx, VOCs, and CO₂ emissions are located within the Yangtze River Economic Belt; those with higher potential to co-control SO₂ and CO₂, and PM_2.5 and CO₂ are in southern and northeast China, respectively. What&rsquo;s more, a further deconstruction of sectoral emissions in 2021 has suggested future reduction measures. For example, controlling coal consumption in the energy field; promoting innovative technologies with low air pollutant emission intensities and coal-saving effects in the iron and steel industry; combining coal and carbonate replacing technologies with separated particle control measures in the cement industry; controlling light-duty passenger vehicle, heavy-duty truck, agricultural machinery, and inland water transport in the transport field. Our dataset and analysis can provide insights into future co-control of air pollutants and CO₂ emissions for China and other countries with the same demand worldwide. Our ABaCAS-EI v2.0 dataset can be accessed from <a href="https://doi.org/10.6084/m9.figshare.21777005.v1" target="_blank" rel="noopener">https://doi.org/10.6084/m9.figshare.21777005.v1</a> (Li et al., 2022) by species, sector, and province.