Study on Carbon Emission Reduction Efficiency and Influencing Factors in Various Provinces in China

<sec><title>Objective</title> The world is still in a phase of rapid industrialization and urbanization. Excessive carbon emissions has become the primary root cause of various urban or even global environmental problems, further impacting human physiological and psychological health. Cities are the largest sources of carbon emissions and are crucial regions for achieving carbon neutrality goals. Urban blue-green infrastructure (UBGI), comprising natural, semi-natural, or artificial green and blue spaces within cities, is considered as the most important carbon sink space in urban areas and has increasingly attracted widespread attention from researchers. However, there are still many unresolved issues regarding the effectiveness of UBGI in carbon sink enhancement and emission reduction: 1) How is the energy efficiency of carbon sink enhancement and emission reduction measured, and what factors influence it? 2) What are the mechanisms and pathways through which UBGI enhances carbon sink and reduces carbon emission? 3) How can UBGI be regulated to better enhance its effectiveness in carbon sink enhancement and emission reduction? 4) What are the limitations and potential directions for future research? This research aims to address these issues and propose scientifically sound planning strategies for UBGI construction to achieve urban carbon neutrality goals. </sec><sec><title>Methods</title> Through literature synthesis and deduction, this research organizes and analyzes the multi-scale measurement methods for UBGI’s efficiency in carbon sink enhancement and emission reduction, identifies corresponding influencing factors at each scale, and constructs multi-scale planning strategies for UBGI based on the logical framework of “measurement methods–influencing factors – planning strategies”. </sec><sec><title>Results</title> The research proposes UBGI planning strategies across three spatial scales (site, community and urban area), covering three key aspects: Carbon sequestration and sink enhancement, carbon reduction based on temperature reduction (or preservation), and travel-related carbon reduction. Based on current research gaps and planning needs, five major research topics are further identified. This research provides a detailed analysis of the measurement methods and influencing factors of UBGI’s efficiency in carbon sink enhancement and emission reduction from three perspectives: Carbon sequestration and sink enhancement, carbon reduction based on temperature reduction (or preservation), and travel-related carbon reduction. The research finds significant differences in the measurement methods for UBGI’s efficiency in carbon sink enhancement and emission reduction efficiency across different scales. Contradictory results may occur at different scales, and large-scale research often lacks characterization of internal features, leading to unclear mechanisms of influencing factors and obstructing practical planning. Based on the interpretation of UBGI’s mechanisms for carbon sink enhancement and emission reduction at different scales, this research formulates UBGI planning strategies across three spatial scales (site, community, and urban area). These strategies include: 1) At the site scale, for carbon sequestration and sink enhancement – carbon sink at the source, land balance, and ecological design; for emission reduction – symbiosis with buildings and integration into daily life. 2) At the community scale, for carbon sequestration – overall balance of revenue and expenditure, precise positioning, and proper interconnection of the carbon chain; for emission reduction – incorporation of cool islands and co-construction. 3) At the urban area scale, for carbon sequestration – enhancement of ecological space management and establishment of a carbon-safe pattern; for emission reduction – demand-based layout and organic dispersion. Finally, the research proposes five major research topics for the planning of UBGI’s carbon sink enhancement and emission reduction: How to construct unified measurement methods for UBGI’s efficiency in carbon sink enhancement and emission reduction across scales? How to measure UBGI’s efficiency in carbon reduction based on temperature reduction (or preservation) at the site scale? How to integrate the pathways of carbon sink enhancement and emission reduction for a life cycle assessment of UBGI? How to balance UBGI’s carbon sink enhancement and emission reduction with other functions to achieve the optimal layout for comprehensive benefits? How to achieve urban “carbon justice” through UBGI? </sec><sec><title>Conclusion</title> The carbon sink pathway of the strategy framework requires “carbon sink at the source – precise positioning – safe pattern”, and the emission reduction pathway requires “symbiotic integration – co-construction and sharing – organic dispersion”. The key trade-offs between these two pathways at three spatial scales may provide theoretical support and practical guidance for UBGI construction and management. The five major research topics mentioned above may offer valuable assistance for UBGI construction and future research. </sec>

Global income inequality is widening and carbon emissions remain high. So, reducing carbon emissions and income gap are urgent challenges. The purpose of this paper is to analysis how carbon emission efficiency influences the region income inequality. The improvement of carbon emission reduction efficiency has widened the regional income inequality with the flow of high-tech labor as an intermediary variable in China. Methods used in this article are mediating effect model and DEA method. This paper constructs a disposable income model of income and health costs, where health costs are a function of carbon reduction. If income is fixed, then the expectations of disposable income will change as the level of carbon emission reduction changes. This study finds that the disposable income expectations of high-income areas increases, while the disposable income expectations of lower-income areas decrease with the improvement of carbon emission reduction efficiency. High-income regions attract high-income labor from other regions, resulting in the widening of regional income inequality under the constraint of high cost of living. This result is verified by the data of China from 2007 to 2017. The regression model with Geordie coefficient as the dependent variable, carbon emission reduction efficiency as the core independent variable, gravitation of high-tech talent as the mediator variable, and urbanization rate, educational level, social security coverage, and highway and railway traffic mileage as control variables not only verifies the above results but also finds that high-tech talents’ flow is not the only intermediary between carbon emission reduction efficiency and regional income inequality. This paper finds that when the carbon emission reduction efficiency increases by one unit, the income inequality gap of 25 provinces increases by 0.0202 units, provinces with high carbon emission reduction efficiency increases by 0.107 units, and provinces with medium carbon emission reduction efficiency increases by 0.026 units. However, the income inequality gap of provinces with low carbon emission reduction efficiency decreases by 0.0390 units. The carbon emission reduction efficiency of the high and medium carbon emission reduction efficiency groups is proportional to the income inequality, while the low carbon emission reduction efficiency group is the opposite, when the carbon emission reduction efficiency is grouped into high efficiency group, medium efficiency group, and low efficiency group. The reason for this result is that the high carbon emission reduction efficiency of the former attracts high-income high-tech talent, while the latter's narrowing regional income inequality benefits from the reduction costs of health and the government’s ecological compensation. The effective measures to narrow the income inequality are to implement carbon emission reduction policy, industrial policy, education investment policy, and public service policy, according to the above findings.

China’s power enterprises consume a large amount of energy and emit a high quantity of carbon dioxide. To reduce carbon emissions and save energy, China has implemented various energy-saving and emission reduction (ESER) policies in the power industry. The purpose of this study is to analyze the carbon emission reduction (CER) performance and the ESER performance of China’s power enterprises. The data envelopment analysis was applied to obtain the CER efficiency and the ESER efficiency of power enterprises in subtropical and temperate regions of China. The research findings are as follows. First, the average ESER efficiency of Chinese power enterprises is lower than their CER efficiency. Second, only 30% of Chinese power enterprises have both high CER and ESER efficiency. Most power enterprises in China need to take measures to further reduce carbon emissions and improve the efficiency of resource utilization. Third, due to their high economic development and advanced use of technology, the CER efficiency of power enterprises in subtropical regions is higher than that in temperate regions. Based on empirical results, specific policy recommendations are provided for Chinese power enterprises.

Evaluation and spatial convergence of carbon emission reduction efficiency in China's power industry: Based on a three-stage DEA model with game cross-efficiency

Taking 39 industries as independent decision-making units in Liaoning Province from 2003 to 2012 and considering the benefits of energy, economy and environment, we combined direction distance function and radial DEA method to estimate and decompose the energy conservation and carbon emissions reduction efficiency of the industries. Carbon emission of each industry was calculated and defined as an undesirable output into the model of energy saving and carbon emission reduction efficiency. The results showed that energy saving and carbon emission reduction efficiency of industries had obvious heterogeneity in Liaoning Province. The whole energy conservation and carbon emissions reduction efficiency in each industry of Liaoning Province was not high, but it presented a rising trend. Improvements of pure technical efficiency and scale efficiency were the main measures to enhance energy saving and carbon emission reduction efficiency, especially scale efficiency improvement. In order to improve the energy saving and carbon emission reduction efficiency of each industry in Liaoning Province, we put forward that Liaoning Province should adjust industry structure, encourage the development of low carbon high benefit industries, improve scientific and technological level and adjust the industry scale reasonably, meanwhile, optimize energy structure, and develop renewable and clean energy.

The negative effects of global warming are becoming more and more serious. The fundamental way to prevent global warming is by reducing carbon dioxide emissions. Achieving this has become a key concern for all countries. The logarithmic mean divisia index model was constructed to decompose the total carbon emission increment. Carbon finance effect was divided into green credit effect and carbon trading effect to analyze the impact of carbon finance on carbon emissions. The results showed that the total carbon emission reduction value caused by green credit effect from 2010 to 2016 in the Beijing-Tianjin-Hebei region was 66193.96 million tons, and the added value of carbon emission caused by carbon trading effect was 80266.68 million tons. There are regional differences in the effects of carbon finance on carbon emissions in these regions. It can be concluded that to a certain extent, green credit can reduce carbon emissions, and carbon trading can increase carbon emissions. Using the gradual expansion of carbon finance trading and market mechanism of carbon finance to solve the problem of carbon emission can improve the efficiency of carbon emission reduction.

This study considers a low-carbon supply chain model comprised of a capital-constrained manufacturer and a retailer under a cap-and-trade system. These two parties can choose from two financing modes: bank financing or mixed financing, in which the latter combines bank financing with equity financing. Two decision-making power structures are formulated, namely the Nash game model and the retailer-led Stackelberg game model. Subsequently, a comparative analysis of equilibrium outcomes for both parties within these power structures is performed, yielding the following insights: (1) In the bank financing mode, retailers find greater profitability in adopting dominance. When emission reduction efficiency is high, manufacturers obtain more profit within a Nash game context. However, when emission reduction efficiency is low, manufacturers accrue more profit in a Stackelberg game context. In the mixed financing mode without cap-and-trade regulations, supply chain participants do not express a preference for any specific game structure. (2) Without cap-and-trade regulation, in both the Nash and Stackelberg game models, the supply chain participants find more profitability in mixed financing when carbon emission reduction efficiency is high. Meanwhile, bank financing proves more profitable when the carbon emission reduction is low. Moreover, this study investigates the impact of wholesale and retail prices of low-carbon products on the financing strategies of the supply chain participants under different power structures and financing modes. Additionally, extended models are considered, including the manufacturer-led Stackelberg game structure and the capital-constrained manufacturer with a certain amount of initial capital.

Faced with increasingly strict carbon emission control, high-emission enterprises need scientific and rational management systems and methods to strengthen carbon emission reduction management. Among the many management systems and methods, the carbon budget has become an effective emission reduction management tool, allowing the planning of carbon emissions and emission reduction activities and rational arrangement of economic inputs. However, judging from the research status and business practices in China and abroad, there is no general carbon budget system to guide the development of carbon emission and emission reduction activities. Based on this background, this paper first attempts to construct an enterprise carbon budget system comprising four sub-budgets: carbon emission, carbon emission reduction and cost, carbon emission rights trading, and carbon emission reduction net profit/loss. It draws on the idea of interactive control to consider the impact of changes in carbon prices, energy prices, and policy guidelines on carbon emission reductions and losses. A carbon budget management system based on interactive control is then constructed and applied to China National Aviation Holding Air China Group (AC Aviation). The research results show that the carbon budget system based on interactive control can dynamically adjust carbon emission reduction behavior based on changes in carbon and energy prices to make carbon budgeting a more viable carbon reduction tool and institutional arrangement.

The Hu-Bao-O-Yu urban agglomeration is an important energy exporting and high-end chemical base in China, and is an important source of carbon emissions in China. The early achievement of peak carbon emissions in this region is particularly crucial to achieving the national carbon emission reduction targets. However, there is a lack of multi-factor system dynamics analysis of resource-dependent urban agglomerations in Northwest China, as most studies have focused on single or static aspects of developed urban agglomerations. This paper analyses the relationship between carbon emissions and their influencing factors, constructs a carbon emission system dynamics model for the Hu-Bao-O-Yu urban agglomeration, and sets up different single regulation and comprehensive regulation scenarios to simulate and predict the carbon peak time, peak value, and emission reduction potential of each city and urban agglomeration under different scenarios. The results show that: (1) Hohhot and Baotou are expected to reach peak carbon by 2033 and 2031 respectively, under the baseline scenario, while other regions and the urban agglomeration will not be able to reach peak carbon by 2035. (2) Under single regulation scenarios, the effect of factors other than the energy consumption varies across cities, but the energy consumption and environmental protection input are the main factors affecting carbon emissions in the urban agglomeration. (3) A combination of the economic growth, industrial structure, energy policy, environmental protection, and technology investment is the best measure to achieve carbon peaking and enhance the carbon emission reduction in each region as soon as possible. In the future, we need to coordinate the economic development, energy structure optimisation and transformation, low-carbon transformation of industry, strengthen research on carbon sequestration technology, and further increase the investment in environmental protection to make the Hu-Bao-O-Yu urban agglomeration a resource-saving urban agglomeration with an optimal emission reduction.

One of the key issues facing the government in achieving carbon neutrality is what methods can be used to effectively reduce carbon emissions. Taking manufacturing enterprises as an example, this paper studies the carbon emission reduction effects of green technology innovation subsidy (GIS), carbon tax (CT), and carbon emission trading (CET). Under the background of social welfare and carbon emission reduction efficiency, we get the results of optimal carbon emission reduction measures in different environments. The results are as follows: (1) In the initial and mature stage of green technology innovation, GIS is the best choice to improve the degree of green manufacturing and maximize social welfare. CT and CET are the best choice to obtain the highest SE (carbon emission reduction efficiency). (2) In the transitional stage, CET and CT can promote the maturity of green technology. However, with the maturity of green technology, the promotion of green technology has weakened. CT is the best choice to achieve the highest SE. (3) When the carbon tax or carbon trading price is at a high or low level, raising the tax rate or carbon trading price can increase the income of enterprises. Therefore, the government should take measures according to the objectives of different stages. When the goal is to maximize social benefits, GIS is the best choice in the initial stage and transition stage, and CET or CT is the best choice in the transition stage. In the initial stage and fertilization stage, when the highest SE, CT, or CET is the best choice, while in the transition stage, CT is the best choice.

Carbon emission reduction analysis for cloud computing industry: Can carbon emissions trading and technology innovation help?

Magnesium and calcium-rich waste powder (MWP) has the potential to be a low-carbon geopolymer cementitious material. This study investigates the mechanical properties and hydration products of low-carbon magnesium and calcium-rich waste powder geopolymer paste (LMWP). The influences of alkali content, calcination temperature, mix proportions of raw materials and curing temperature on the compressive strength and hydration of LMWP were examined. The mechanical properties of LMWP were systematically evaluated by assessing setting time, fluidity, and compressive strength, while the pore structure was analyzed using mercury intrusion porosimetry (MIP). The hydration products and microstructures of LMWP were investigated by XRD, TG-DTG, and SEM-EDS. The results indicated that incorporating 1 % NaOH significantly enhanced the compressive strength of LMWP, whereas thermally activated MWP (800 ℃, 900 ℃) negatively affected compressive strength development. The addition of slag facilitated the reaction of MWP and improved the compressive strength of LMWP. When the slag incorporation reached 40 %, the specimen demonstrated optimal performance with a compressive strength of 27.8 MPa. The pore diameter was predominantly distributed around 10 nm, indicating well-structured porosity. Microstructural analysis revealed that the hydration products are dense calcium magnesium silicate gels (C-M-S-H), which significantly enhanced the compressive strength and optimized pore structure of LMWP. The efficiency of carbon emission reduction achieved by LMWP was evaluated. The findings indicate that, compared to traditional cement-based materials, LMWP reduces cement consumption by over 60 %, significantly decreasing CO2 emissions. This study innovatively utilizes MWP to prepare green and low-carbon geopolymer paste materials, with the aim of replacing cement applications in the construction industry, thereby reducing carbon emissions. It explores new avenues for the low-carbon and green development of the civil engineering sector and contributes to efforts in addressing the global climate crisis.

Optimal strategies for production plan and carbon emission reduction in a hydrogen supply chain under cap-and-trade policy

The application of magical microalgae in carbon sequestration and emission reduction: Removal mechanisms and potential analysis

Carbon emissions of water supply systems in China: Characteristic, right, right balance and reduction potential assessment