Dear Colleagues,

As the largest CO₂ emitter, China has proposed a “Dual Carbon” target, an aim to achieve its carbon peak by 2030 and carbon neutrality by 2060. Carbon emission reduction and carbon sink enhancement are fundamental pathways for achieving carbon neutrality. Uncovering the patterns, process mechanisms, and evolutionary trends of carbon sources and sinks, as well as their interactive mechanisms with the climate system, is significant for achieving carbon neutrality and sustainable development.

The journal Atmosphere is hosting a Special Issue to disseminate the most recent findings related to carbon emissions and carbon neutrality in China. Topics of interest include, but are not limited to, the following:

• Innovative methods of carbon accounting and calculation;
• Spatial–temporal patterns of major carbon sources;
• Spatial–temporal patterns of carbon sinks;
• Regional carbon cycle process;
• CO₂ flux measurement;
• Carbon sink potential assessment.

Dr. Ji Zheng
Dr. Yu Li
Dr. Yingjie Hu
Guest Editors

Manuscript Submission Information

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Atmosphere is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• carbon emission
• carbon neutrality
• decarbonization pathway
• spatiotemporal characteristics
• driving mechanism

Title: Features, Mechanisms and Optimization of Embodied Carbon Emissions for Typical Industrial Province: Case Study of Hebei, China
Authors: Suocheng Dong; Qian Liu; Fujia Li*; et al.
Affiliation: Chinese Academy of Sciences
Abstract: In countries with rapid economic growth and rapid increase in carbon emissions, embodied carbon emissions from inter-provincial trade significantly affects the amount and structure of carbon emissions, and a key issue that needs to be considered when formulating carbon emission reduction policies. The carbon emission reduction task of typical industrial provinces has become a major challenge to achieve carbon neutrality. In this research, we chose Hebei, as the case area, and 1997-2017, the key stage of rapid energy consumption and carbon emissions, as the research period. We comprehensively used EEBT model, SDA model, and CR model to explore the spatio-temporal feature and mechanism of embodied carbon emissions from inter-provincial trade (ECEs-PT) in Hebei. The results showed that the spatio-temporal development characteristic of net ECEs-PT outflow in Hebei, is expanded coverage. Net ECEs-PT is highly concentrated in metal smelting and rolling processing (MetalSmelt) and petroleum processing, coking, and nuclear fuel processing (RefPetraol). Moreover, the ECEs-PT driving forces were technology, structure and scale. A rapid increase in interprovincial demand had led to a high concentrations of trade structures in Hebei. While trade expands, the pressure of CEs reductions increasing. Finally, we discussed optimization for different types of sectors. The results could provide scientific support for similar areas to reduce carbon emissions and achieve carbon neutrality more efficiently.

Title: Impacts of Urban Rail Transit on Carbon Emissions in China: Focusing on Traffic Diversion and Creation Effects
Authors: Yifu Ou; Ji Zheng; Kyung-Min Nam*
Affiliation: The University of Hong Kong
Abstract: In this study, we examine the net effects of urban rail transit on carbon emissions in 93 Chinese cities, taking a structural equation modeling approach. Urban rail transit theoretically helps mitigate transport-sector emissions by absorbing part of vehicle traffic volume or generating traffic-diversion effects. However, its net contribution to mitigation is not certain given potential traffic-creation effects, since improved rail access can also incentivize new developments and thus induce additional on-road traffic. In contrast to many existing studies neglicting the latter, we analyze both of these opposing effects within a single framework, where primary rail-associated emission channels are explicitly modeled. Our central results show that urban rail density is negatively associated with traffic-related carbon emissions, and speak for the dominance of the traffic-creation effects in China’s context. However, mixed evidence exists on the effects of increased urban rail density on vehicle-kilometers traveled, suggesting relative balance between the two effects. In fact, our follow-up path analysis demonstrates that the traffic-diversion effects tend to be gradually overshadowed by the traffic-creation effects. These findings suggest that transport-sector mitigation needs coordination between urban rail development and planning regulations.

Title: Spatiotemporal Analysis of urban carbon metabolism and its response to land use change using CASA and ecological network model: A case of Beijing, China
Authors: Yingjie Hu; Ji Sun; Ji Zheng*
Affiliation: The University of Hong Kong
Abstract: Analyzing the spatial pattern of urban carbon metabolism could provide insights into the spatial adjustments to mitigate the greenhouse effect. Using CASA and ecological network model, we quantitatively analyzed and mapped the spatial patterns of urban carbon metabolism and its response to land use change and urbanization from 2000 to 2020. The result showed that the carbon sequestration only offset 6.08% of carbon emission, indicating a serious imbalance of the urban carbon metabolism in Beijing. In the meantime, the carbon sequestration increased by 15.48% and the carbon emission almost doubled during the study period. The harmful carbon transitions always sourced from the south-eastern suburban area while most beneficial carbon transitions were in the urban central area and north-western mountainous areas. The spatiotemporal change of urban carbon metabolism was highly correlated with the land use transition, and the land use change from cultivated land to industrial land accounted for 58.76% of the harmful carbon transitions. These results of key carbon flow and area help provide insights for policymaking in effective management of the spatial patterns of carbon emission and sequestration.

Title: Measurement of Embodied Carbon Emissions in Cross-strait Trade and Decomposition of Influencing Factors
Authors: Baoguo Shi†，Xiaodan Bai†，Yanjie Wang，Wenjing Xiang，Yu Cao，Guihong Geng，Ji Zheng*
Affiliation: Minzu University of China
Abstract: The impact of embodied carbon emissions by trade and associated carbon emissions transfer on the distribution of carbon emission responsibility between countries or regions has become a key issue of climate governance. In this study, we choose Mainland of China and Taiwan as the research regions, and take 2005-2020 as the research period. We comprehensively applied the multi-regional input-output model (MRIO), structural decomposition analysis (SDA) and other methods to study the change of embodied carbon emissions in cross-strait trade, the direction of embodied carbon emissions in cross-strait trade, and the factors influencing the embodied carbon emissions in the import and export trade between the two regions and the degree of impact. The results showed that there is a positive correlation between the embodied carbon emissions in cross-strait trade and the total import and export trade in the study period. The rapid increase of embodied carbon emissions in the trade is mainly due to the growth of trade scale between the two regions. Technological effect can promote and inhibit the growth of embodied carbon emissions, and the effect is obvious. Structural effect can restrain embodied carbon emissions, but the effect is not obvious. Under the combined action of the three effects, the overall effect is still promoting the increase of carbon emissions. Based on our findings, we propose relevant policy recommendations to reduce the embodied carbon emissions in cross-strait trade, so as to help China achieve the dual carbon target within the commitment period.