A network analysis of indirect carbon emission flows among different industries in China

Identifying the drivers of changes in embodied food-energy-water in the Bohai mega-urban region, China: A perspective of final demands

Food-energy-water (FEW) systems in the Bohai mega-urban region (MUR) have experienced astonishing changes in recent decades; however, the dynamics of these changes are not fully understood. This study combined an ecological multiscale input-output model and a structural decomposition analysis (SDA) to explore the variation in embodied FEW consumption and its drivers. The results showed that, although almost all sectoral embodied FEW intensities decreased, embodied FEW demands increased by approximately 9.9×10⁸ tons, 4.61×10⁷ TJ and 1.1×10¹¹ m³ over 10-year period. The embodied FEW flow diagrams show that local consumption and trade were strengthened. Urban household consumption, fixed capital formation and exports were the main components affecting the embodied FEW use increases. An SDA revealed that the consumption level effect (∆c) was the dominant contributor that promoted the increase in the Bohai MUR's embodied FEW consumption. The scale effect (∆p) also had a positive effect on the embodied FEW consumption increases. The technological effect (∆e) was the primary contributor to offset the embodied FEW consumption increase. The economic efficiency effect (∆L) and structural effect (∆s_d) also contributed to offsetting the total embodied FEW consumption increase. The effect of the change in domestic and foreign imports (∆D and ∆F) impacted the increase in embodied FEW mainly through the change in the embodied FEW intensities and trade volumes. This study identified the changes in FEW systems and highlighted future coping strategies.

Identification of Key Carbon Emission Industries and Emission Reduction Control Based on Complex Network of Embodied Carbon Emission Transfers: The Case of Hei-Ji-Liao, China

Similar to the problems surrounding carbon transfers that exist in international trade, there are severe carbon emission headaches in regional industrial systems within countries. It is essential for emission reduction control and regional industrial restructuring to clarify the relationship of carbon emissions flows between industrial sectors and identify key carbon-emitting industrial sectors. Supported by the input-output model (I-O model) and social network analysis (SNA), this research adopts input-output tables (2017), energy balance sheets (2021) and the energy statistics yearbooks (2021) of the three Chinese provinces of Hei-Ji-Liao to construct an Embodied carbon emission transfer network (ECETN) and determine key carbon-emitting industrial sectors with a series of complex network measurement indicators and analysis methods. The key abatement control pathways are obtained based on the flow relationships between the chains in the industrial system. The results demonstrate that the ECETNs in all three provinces of Hei-Ji-Liao are small-world in nature with scale-free characteristics (varying according to the power function). The key carbon emission industry sectors in the three provinces are identified through centrality, influence, aggregation and diffusion, comprising coal mining, the chemical industry, metal products industry, machinery manufacturing and transportation in Liaoning Province; coal mining, non-metal mining, non-metal products, metal processing and the electricity industry in Jilin Province; and agriculture, metal processing and machinery manufacturing in Heilongjiang. Additionally, key emission reduction control pathways in the three provinces are also identified based on embodied carbon emission flow relationships between industry sectors. Following the above findings, corresponding policy recommendations are proposed to tackle the responsibility of carbon reduction among industrial sectors in the province. Moreover, these findings provide some theoretical support and policy considerations for policymakers.

The impact of shadow banking activities on carbon dioxide emissions: empirical evidence from China

Financial activity plays an important role in the analysis of environmental and ecological implications. Previous research shows that shadow banking activities, informal and less regulated financial activities, have become an important part of financial systems after the 2008 financial crisis. However, the impact of shadow banking activities on carbon dioxide emissions has been ignored in previous research. In this paper, we use the panel annual data of 30 Chinese provinces over the period 2013-2020 to study the effect of shadow banking activities on carbon dioxide emissions. The result shows that shadow banking activities have a positive impact on carbon dioxide emissions, and the result is still robust by using dynamic panel regression with general method of moments (GMM) method. Heterogeneity analysis shows that the impact of shadow banking activities on carbon emissions is more pronounced for the secondary industry, which proves that shadow banking activities support more for environmentally unfriendly businesses. Furthermore, by using difference-in-difference (DiD) method, we examine the causal effect of shadow banking regulation policy on carbon dioxide emission reduction and demonstrate that the shadow banking regulation can reduce carbon dioxide emissions. Our research contributes to environment protection and achieving the goal of low-carbon economy by exploring the role of shadow banking activities and financial regulation in carbon dioxide reduction.

Characteristics Analysis and Identification of Key Sectors of Air Pollutant Emissions in China from the Perspective of Complex Metabolic Network

Presently, China is in a critical period of economic transformation and upgrading. At the same time, it is also facing the pressure of serious atmospheric environmental pollution, which seriously threatens human health and hinders the sustainable economic development. Air pollutants are closely related to economic sectors, which together constitute a complex network. Air pollutants form an input–output ecological metabolic relationship among different sectors. Therefore, from the perspective of complex metabolic network, this study first constructs an environmental input–output model and then comprehensively uses the relevant methods of ecological network analysis and complex network analysis to analyze the characteristics of China’s air pollutant emission system. Secondly, the key joint sectors of NO_x and PM emissions are determined from the supply side and the demand side, respectively. Finally, the corresponding emission reduction measures are proposed for the identified key sectors.

A complex network perspective on embodiment of air pollutants from global oil refining industry

The air pollutants emitted from oil refining industry could be transferred across borders through the increasingly complex global trade network. However, the specific structural features of the network remain unclear. Based on the Multi-regional Input-output method and complex network theory, we make a first attempt to trace six oil refining air pollutants embodied in the international trade. The results show that the overall character of the global oil refining air pollutants flow network exhibits small-world behavior, and each node of the network is strongly connected. Therefore, the refining emissions mitigation measures of one node could efficiently radiate to the other nodes connected to it, which provides essential opportunities for collaborative emissions reduction among countries. Besides, the individual characteristics of each node are distinguished, several key nodes dominate the embodied emissions throughout the global oil refining air-pollutants flow network. For specific countries, the United States, China, Japan, and the United Kingdom are the hub economics in importing embodied pollutants in the network, while Russia and Canada are the key exporters. Similarly, the critical paths with large flow still come from the trade between these key nodes. Our estimated results have great policy implications for reducing air pollutants emitted from oil refining industry and also have profound implications for environmental regulation and protection in the world.

Strategies to achieve a carbon neutral society: a review

The increasing global industrialization and over-exploitation of fossil fuels has induced the release of greenhouse gases, leading to an increase in global temperature and causing environmental issues. There is therefore an urgent necessity to reach net-zero carbon emissions. Only 4.5% of countries have achieved carbon neutrality, and most countries are still planning to do so by 2050-2070. Moreover, synergies between different countries have hampered synergies between adaptation and mitigation policies, as well as their co-benefits. Here, we present a strategy to reach a carbon neutral economy by examining the outcome goals of the 26th summit of the United Nations Climate Change Conference of the Parties (COP 26). Methods have been designed for mapping carbon emissions, such as input-output models, spatial systems, geographic information system maps, light detection and ranging techniques, and logarithmic mean divisia. We present decarbonization technologies and initiatives, and negative emissions technologies, and we discuss carbon trading and carbon tax. We propose plans for carbon neutrality such as shifting away from fossil fuels toward renewable energy, and the development of low-carbon technologies, low-carbon agriculture, changing dietary habits and increasing the value of food and agricultural waste. Developing resilient buildings and cities, introducing decentralized energy systems, and the electrification of the transportation sector is also necessary. We also review the life cycle analysis of carbon neutral systems.

Inter-provincial sectoral embodied CO2 net-transfer analysis in China based on hypothetical extraction method and complex network analysis

To address the CO₂ emissions issue, China promised to increase its nationally determined contributions, trying to reach a CO₂ emissions peak by 2030. For optimizing emission reduction policies, it is important to clarify the CO₂ linkage structure and transfer characteristics. Previous research mainly focused on the calculation and comparison of CO₂ linkage at the national level or the regional level and lacked inter-provincial sector-sector transfer analysis. This study uses hypothetical extraction method (HEM) to calculate the inter-provincial sectoral linkages of embodied CO₂ in 2012 and 2015, providing a new perspective for sectoral CO₂ linkage studies in China. We use net transfer to reveal the impact of provincial trade on the embodied CO₂ emissions, and identify key CO₂ emitter sectors. Combined with complex networks, we describe the clustering feature visualized and identify the transfer media sectors. The results are as follows: (1) the key sectors with large linkage are mainly the heavy industries located in North China. The electricity industry has the largest net CO₂ outflow as the energy supplier, whereas the construction industry has the largest net inflow as the driving sector. (2) The CO₂ transfer networks present closely connected and spatial clustering features, reflecting the embodied CO₂ linkage between geographically adjacent sectors closer. (3) The important media sectors are mostly located in northwest China with small industrial scale and linkage degrees, such as the transport equipment industry in Shanxi. Emission reduction policies should be overall planned and tailored to local conditions. Consequently, possible policy implications of the results are discussed, which could provide additional insights for CO₂ mitigation.

"New normal" characteristics show in China's energy footprints and carbon footprints

Around the 2010s, China's economy has entered a "new normal" stage-transitioning from an extensive to an intensive growth mode. This study aims to investigate whether China's energy and carbon footprints also show these "new normal" characteristics. We evaluate China's energy and carbon footprints of 42 sectors from 2007 to 2017. The "new normal" characteristics are reflected from three dimensions: trend, structure, and driving factor. The results show that while the growth rate of China's energy and carbon footprints has slowed down, the total footprints are still increasing. The footprints induced by consumption have gradually exceeded those induced by export, and the tertiary industrial sectors became critical nodes in footprint networks. Furthermore, economic structure and development level have been major drivers of energy and carbon footprint growth. The findings reveal that China's energy and carbon footprints show similar "new normal" characteristics as economic development. This supports the targeted formulation of China's future policies to achieve sustainable development.

The embodied CO2 transfer across sectors of cities in Jing-Jin-Ji region: combining multi-regional input-output analysis with complex network analysis

The CO2 emission transfer at city level, especially across sectors of cities, has not yet been sufficiently quantified. This paper analyzes the embodied CO2 transfer across sectors of 13 cities in Jing-Jin-Ji region (Beijing-Tianjin-Hebei in China) combining multi-regional input-output analysis with complex network analysis. The results show that (1) most embodied CO2 transfers are concentrated in a few sectors and emission reduction effects on these sectors can be quickly extended to the entire embodied CO2 transfer network (ECTN). (2) The electricity and hot water production and supply sector in Beijing have the most embodied CO2 export partners and the strongest control over embodied CO2 transfer. The construction sector in Beijing has the most embodied CO2 import partners and greatest influence on the ECTN. (3) At city level, 90% of embodied CO2 transfers occur within the city, and the general direction of embodied CO2 transfer across cities is from resource-rich cities, Tangshan and Handan, to developed cities, Beijing and Tianjin. At sector level, the largest embodied CO2 transfer path is electricity and hot water production and supply → metallurgy → construction sector. (4) Embodied CO2 transfers of sectors in the same or adjacent cities are denser. Collection of sectors in Beijing and Tianjin is the densest embodied CO2 transfer community.

Research on China's embodied carbon transfer network in 2012 from the perspective of provinces and sectors

Resource endowment and economic development of different provinces in China vary greatly, resulting in large amount of CO₂ transfers. We need further exploration to help decision makers allocate emission responsibilities reasonably. We construct China's embodied CO₂ transfer network (CTN) in 2012 from the perspective of provinces and sectors based on multi-regional input-output (MRIO) model and complex network analysis. The key CO₂ transfer nodes and paths, final demand decomposition, topological structure, clustering characteristics, and influencing factors are analyzed. The results show that the average CO₂ transfer length from one province (sector) to another is only 1.323 (1.584). The top three net CO₂ importers (45.39% of the total), located in developed eastern coastal area, mainly import CO₂ from energy-rich but underdeveloped provinces such as Heilongjiang. It presents a CO₂ transfer pattern from north to south and from west to east. CO₂ transfer in energy industry is mainly driven by urban household consumption. Non-adjacent provinces with distance greater than 750 km have no significant spillover effect and difference in technology level has the greatest impact on CTN. This work is important for differentiating the roles of provinces and sectors in CTN, guiding the allocation of carbon credits and controlling total CO₂ emissions.

Carbon emissions, the industrial structure and economic growth: Evidence from heterogeneous industries in China

A comprehensive understanding of the relationships among carbon emissions, the industrial structure and economic growth holds great significance for China's transition to a low-carbon economy, industrial structure optimization, and achievement of energy conservation and emission reduction targets. We selected six major industrial sectors (agriculture, industry, construction, transportation, retail and accommodation and other industries) as research objects, introduced the extended STIRPAT decomposition model, Tapio decoupling model and the grey relation analysis to discuss the relationship among the three. Results showed that (i) since 2000, the proportions of value added of agriculture, manufacturing, and transportation are negatively correlated with carbon emissions, while those of construction, retail and accommodation, and other industries are positively correlated with carbon emissions. (ii) The overall economic growth and carbon emissions of these six major industries have experienced the process of decoupling-coupling-decoupling-coupling-decoupling. (iii) The relevance of these six industries to GDP is ranked as follows: transportation > manufacturing > retail andaccommodation > agriculture > construction > other industries. Additionally, accelerating the achievement of a clean energy structure, strengthening the strength and speed of industrial structure adjustment and reducing the dependence on fossil energy are the key steps for China to reach carbon emissions peak goal.

Analyzing carbon emission transfer network structure among provinces in China: new evidence from social network analysis

Domestic trade plays a key role in China's rapid economic progress. However, the increased domestic trade causes significant variations in carbon emission transfer among provinces. This study adopted the multi-region input-output (MRIO) model and social network analysis (SNA) to estimate the carbon emission transfer. Furthermore, the carbon emission transfer network characteristics among 30 provinces and 27 sectors were analyzed by using interprovincial input-output tables for 2007, 2010, and 2012. The results showed that (1) Large differences exist in carbon emission transfer flow and its network characteristics between provinces. (2) The three industrial sectors of metal smelting and pressing sector, power, heat production, and supply sector, petroleum processing, coking, and nuclear fuel processing sector have high carbon emission transfer and pose a strong influence on the carbon emission transfer network. (3) Provinces of the eastern region have a "bidirectional spillover" role, while those of the western region have a mediating role as an "agent." Provinces of the central region have a "main inflow" role. Finally, useful policy implications and suggestions of this study are summarized.

CO2 flows in the inter-regional and inter-sectoral network of the Yangtze River Economic Zone

As a significant economic region in China, the Yangtze River Economic Zone has close spatial and sectoral linkages and generates considerable CO₂ emissions. Reducing CO₂ emissions in the Yangtze River Economic Zone (YREZ) while considering both inter-regional and inter-sectoral connections has become an essential issue. Based on a multi-regional input-output model and complex network theory, this study constructed a network with inter-regional and inter-sectoral CO₂ emission flows in the YREZ simultaneously to reveal sectoral and spatial transfer pattern and identify the key sectors at the provincial level. The results of density, connectedness, hierarchy, and efficiency showed that the CO₂ flow network was vulnerable and sensitive. The key provincial sectors were identified through different network indicators, including degree centrality, betweenness centrality, and eigenvector centrality. According to their characteristics, the 66 sectors were categorized into different communities with the roles of suppliers, receivers, and intermediaries. The findings of this study provided an integral map of CO₂ emission flows in the YREZ so that the specific and comprehensive policies could be designed from sectoral and provincial level to avoid the offset of different policies.

Identifying key sectors based on cascading effect along paths in the embodied CO2 emission flow network in Beijing-Tianjin-Hebei region, China

The emission of carbon dioxide (CO₂) is a serious environmental issue, especially in Beijing-Tianjin-Hebei region. Unlike previous studies that mainly consider the bilateral and direct connection between two sectors, this study identifies path-based key sectors by considering the cascading effect of a sector on other sectors on paths of the entire economic system. We first construct an embodied CO₂ emission flow network of Beijing-Tianjin-Hebei region, combining environmental input-output analysis and complex network theory. Then, the path-based key sectors are identified by traversing the path of each sector in the network based on cascading failure theory and hypothesis extraction method. On the one hand, the results show that a small number of sectors shoulder a large proportion of the embodied CO₂ emission flows from both path and sector perspectives. On the other hand, we identify some path-based key sectors that did not receive enough attention from the sector perspective. Additionally, the sum of the embodied CO₂ emission flows in about 30 steps accounts for 90% of the total embodied CO₂ emission flows on its supply chain path. To more effectively reduce carbon emission, sectors that connect these 30 steps should be concerned in some policy recommendations. The method proposed in this paper can complement existing methods and contribute to further reducing CO₂ emissions in the Beijing-Tianjin-Hebei region.

A study on carbon transfer and carbon emission critical paths in China: I-O analysis with multidimensional analytical framework

As environmental issues aggravated heavily, China faces increasing pressure and challenges on carbon emission reduction and distribution. we used non-competitive input-output table (I-O table) combined with the methods of Structural Path Analysis (SPA) and Multidimensional Analytical Framework (MAF), based on the data of China in 2012, to analyze the current situation of inter-sector carbon emission transfer and identify the key sectors and the critical paths from multiple perspectives. Our results show that total fixed capital formation is the main final demand. The electricity, petroleum, and metal smelting are the largest carbon outflow sectors, which emit carbon at the upstream of the path. Construction and other services are the most obvious carbon inflow sectors, which belong to the middle and downstream of the path and lead to indirect carbon emissions through their demands for other sectors. "Metal smelting → Construction → Total fixed capital formation," "Nonmetallic products → Construction → Total fixed capital formation," and "Petroleum → Urban consumption," "Electricity → Urban consumption" are the top four paths with large carbon emission, which deserve attention. Finally, this paper puts forward some policy implications on emission reduction based on the results.

Exploring regional differences in the impact of high energy-intensive industries on CO2 emissions: Evidence from a panel analysis in China

China is currently the largest CO₂ emitter in the world. Within China, more than 60% of CO₂ emissions originate from high energy-intensive (HEI) industries. Therefore, controlling and reducing CO₂ emissions from HEI industries is crucial if China is to achieve its 2030 emission reduction targets. This study aims to investigate regional differences in the impact of HEI industries on CO₂ emissions in China. This paper presents an analysis of the impact of HEI industries on CO₂ emissions at the national and regional levels using a modified STIRPAT model and provincial panel data from 2000 to 2015 in China. The results show that HEI industries are significant contributors to China's CO₂ emissions owing to the growth in industries, coal-based energy structure, low level of technology, and outstanding conduction effects. The impact intensity of HEI industries on CO₂ emissions decreases from the western to the central and eastern regions in China because of a huge regional difference in industrial structure, energy structure, R&D investment, and industrial transfer. Our findings have important implications for policymakers in China by indicating that regional policies concerning HEI industries should be differentiated to successfully reduce CO₂ emissions and meet national targets.

A Panel Investigation of High-Speed Rail (HSR) and Urban Transport on China’s Carbon Footprint

Rapid urbanization and industrialization in Chinese cities have substantially elevated carbon emissions, and transportation plays a major role in these emissions. Due to data availability, research on the impact of both high-speed rail (HSR) and other urban transportation modes on urban carbon emissions is rare. Using a relatively large panel of 194 Chinese cities from 2008–2013, we examine the impact of HSR, conventional rail, bus, roads, and subways on urban carbon emissions. We further document the interaction of these transport modes with geo-economic variables, and more accurately measure HSR’s impact on emissions using a comprehensive accessibility metric. During this time, China developed, constructed and began to operate an extensive HSR network. Our results show that increases in HSR lead to rises in carbon emissions, emissions per GDP unit and per capita. We also find that transportation’s impact on carbon emissions differs by city size and region, and transportation modes significantly interact with GDP, population and urban area to affect carbon emissions. These interactions imply that the government’s promotion of HSR over conventional rail may have unintended consequences and boost urban carbon emissions.

Rebound effect of energy efficiency in China's construction industry: a general equilibrium analysis

China has set ambitious targets to reduce its carbon intensity by 2020. Improved energy efficiency is an important strategy to achieve this goal. However, the rebound effect may act as a major obstacle to fully realizing the potential for energy savings. As one of three major energy consumption sectors in China, the construction industry is vital to reducing carbon emissions. This paper established a static computable general equilibrium (CGE) model to study the rebound effect of different energy sources used in the construction industry. The main energy sources used in the construction industry are coal, oil, natural gas, and electricity, and the conclusions show that the largest rebound effect was found for improvements in natural gas efficiency, with an average of 99.20%, while the lowest was for improvements in electricity efficiency, with an average of 83.47%. Moreover, the rebound effect of the primary energy sources (coal, oil, natural gas) was greater than the rebound effect of the secondary energy source (electricity). Our conclusions indicate that improving the energy efficiency in the construction industry will have a positive impact on GDP and on the mitigation of carbon emissions, and the presence of the rebound effect is significant, especially with regard to electricity sources. The implications of the results are that policymakers should primarily focus on improving the efficiency of electricity. In addition, this paper suggests that the rebound effect can be reduced by removing fossil fuel subsidies and imposing a carbon tax.