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Freshwater resources are scarce globally, and the increase in carbon dioxide (CO 2) concentration leads to both a decrease in soil moisture and arid climate, further limiting agricultural production. Therefore, it is critical to achieve water efficiency in agriculture under elevated CO 2 concentration. A comprehensive analysis was conducted on the research topic of efficient agricultural water under elevated CO 2 concentration using bibliometric methods. The results show that the number of papers on this research has changed from an accumulation phase (1992–2005, 395) to a growth phase (2006–2023, 963). "Carbon dioxide", "water-stress", "growth", "photosynthesis", "yield", and other keywords have been the focus of past research in this area. Kimball BA and Ainsworth EA are the most influential authors in this area. Leakey's (2009) paper in "Experimental Botany" was the most contributing study, summarizing six lessons about the effects of CO 2 enrichment on the relationship among carbon, nitrogen, and water in plants. The United States and China were the most influential countries. Over time, research has shifted from an early focus on atmospheric CO 2 change itself to the response of crops to elevated CO 2 in agricultural production. The efficient crop production strategy under the interaction of environmental factors is becoming a hot spot for future research, and the emission and use of greenhouse gases, the improvement of crop quality, and the efficient guidance of models are also worth exploring. Overall, this study presents a quantitative analysis and comprehensive review of past research conducted on the effect of water and fertilizer on agricultural production under CO 2 enrichment. It also offers suggestions and expectations for future research on the hot spot direction of efficient crop production under climate change. • The continuous research attention is closely related to climate change caused by CO 2 enrichment. • The main research fields included CO 2 enrichment, water stress, crop growth and photosynthesis. • The co-citation analysis reveals broad research clusters in the literature. • The new research focus will be interactive climatic factors, greenhouse gas recycling, and modeling. [ABSTRACT FROM AUTHOR]

Mitigating greenhouse gas emissions is a significant global challenge, and precise prediction of carbon emissions holds the utmost importance for China to attain its dual carbon goal. To overcome the limitations of existing studies using a single forecasting method, based on quadratic exponential smoothing, multiple linear regression, and Gaussian process regression models, this paper constructs a carbon emission combination forecasting model with the generalized induced ordered weighted average (GIOWA) operator and analyzes carbon emission reduction performance. Empirical testing utilizing China's carbon emission data from 1980 to 2020 reveals the following findings: (1) The GIOWA combination forecasting model significantly enhances the accuracy of carbon emission forecasts, with an average accuracy exceeding 99.5% over the sample period, surpassing various single forecasting methods. (2) The carbon emission reduction target can be achieved under three different scenarios of low, average, and high GDP growth rates. Specifically, under the low growth rate scenario, China can achieve a 60% reduction in carbon intensity by 2025 and a 65% reduction by 2030. This study offers valuable decision support for the development of effective carbon reduction policies. [ABSTRACT FROM AUTHOR]

Hydrogen produced from renewables-fuelled electrolysis has the potential to provide deep decarbonisation for sectors that are the most difficult to decarbonise, but the intermittency of renewable sources may result in low electrolyser utilisation and, consequently, high costs. This study determines the greenhouse gas (GHG) emissions and levelised cost of hydrogen (LCOH) associated with blending wind electricity with the grid to increase electrolyser utilisation. A novel cost model was developed to determine the production performance, costs and embodied CO 2 emissions of an electrolyser with hybrid fuel supply (wind and grid) considering dynamic load constraints of alkaline (ALK) and Proton exchange membrane (PEM) electrolysers and using high-resolution historical weather data to determine wind production profiles in two case study regions: northern (Bayannur) and southern (Pingtan) China. The results show that using 52% of grid electricity in an ALK electrolyser in Bayannur reduces LCOH by 11%, increasing hydrogen production by 74% but with 17.4 kg CO 2 / kg H 2 generated in CO 2 emissions. When a carbon price is accounted for, the optimal electrolyser utilisation is reduced to 40%, with the LCE 44% reduced. Emissions of 9.8 kg CO 2 /kg H 2 are lower than for stream methane reforming with carbon capture. In Southern China (Pingtan), LCOH is higher than Bayanur because of the high electricity cost. The economic benefits of increasing grid power depend primarily on the total CAPEX cost, grid power cost, and carbon tax. By altering the carbon tax, the optimal blend of wind/ grid differs. The grid contribution to the optimal blend diminishes as a carbon tax approaches 35 USD/ t CO 2. • This paper analyses the value of adding grid electricity to a pure wind-powered H 2 production plant. • The LCOH and CO 2 life-cycle emissions are obtained for Alkaline and PEM electrolysers. • We are introducing the novel ICOH metric to optimise the trade-off of LCOH and CO 2 emission on H 2 production. • Using only 52% of grid electricity in an ALK electrolyser, H 2 production can increase by 75%. [ABSTRACT FROM AUTHOR]

• Four time-delay weights structural types are designed by the grey incidence model. • The novel multivariable grey prediction model considering the time-delay periods and time-delay weights is proposed. • The accumulating impact of influencing factors on CO 2 emissions of China's transport sector is measured. CO 2 emissions from the transportation sector occupy an increasingly important proportion in China's carbon dioxide emissions. Measuring the accumulative impact of factors on carbon emissions over time is of great significance for formulating corresponding policies. This paper aims to propose a novel time-delay multivariate grey model to measure the CO 2 emissions' accumulating impact of China's transportation sector. Firstly, the grey incidence model is used to identify time lags between the input and output variables, and also analyze the structure type of time-delay weights. Then, an accumulative time-delay multivariate grey prediction model is developed. In this model, a Gaussian formula is used to discretize the convolution integral of the time response function, and the particle swarm optimization algorithm is employed to determine the optimal weight coefficients. Finally, a case for CO 2 emissions prediction is adopted to test the effectiveness and practicality of this model compared with the alternative models. The results show that the proposed model outperforms other six competing models in accordance with two measuring indices, and suggestions on emissions mitigation are proposed based on the prediction results. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO 2) is the primary greenhouse gas, with annual emissions reaching up to 54 billion tons globally, leading to an unprecedented acceleration of global warming. In conjunction with carbon capture, utilization, and storage (CCUS), which represents the most advanced and efficient technology for energy conservation and emission reduction, as well as the innovative concept of CO 2 storage in salt caverns, this paper investigates the industrial application potential of supercritical CO 2. Herein the feasibility of large-scale storage of supercritical CO 2 in salt caverns was investigated, focusing on the stability aspect associated with such storage. Specifically concentrating on the impact of upper and lower injection/production pressures and frequencies on the stability of carbon storage in salt caverns, this study utilizes numerical simulation methods to simulate the creep process that occurs in China's bedded salt formations. Numerical simulation results showed that: 1) From the perspective of salt cavern stability, the volume shrinkage, creep and damage degree of surrounding rock during operation all fall within an acceptable range. Consequently, it is feasible to implement carbon storage in these salt caverns for a during of 100 years. 2) Shortening the range of internal pressure will enhance the stability of salt cavern for carbon storage. Furthermore, different pressure intervals have an impact on the creep concentration position within the cavern, primarily resulting in a transformation between internal contraction of surrounding rock and sediment accumulation caused by floor creep by altering the lower pressure limit. 3) The injection and production frequency of salt cavern carbon storage (SCCS) is characterized by a low occurrence rate (<10 cycles). The stability of the cavern can be enhanced by increasing the injection and production frequency, nevertheless, it is important to note that internal pressure remains the primary factor influencing cavern stability compared to the injection and production frequency. • A digital model for supercritical CO2 storage in salt caverns is developed. • The operational parameters for SCCS are designed from the perspective of pressure intervals, injection and production frequencies. • The numerical simulation method is employed to simulate the dynamic change process of SCCS during 100 years of long-term operation, followed by a corresponding stability evaluation. • The alterations in cavity morphology and damage severity of salt caverns utilized for carbon storage are examined. [ABSTRACT FROM AUTHOR]

This paper investigates the decoupling of carbon dioxide (CO 2 ) emissions from agricultural economic growth in 30 Chinese provinces from 1997 to 2014. First, CO 2 emissions from agricultural production activities, farming, and livestock husbandry are computed. Then, this paper explores the spatial and temporal heterogeneity of CO 2 emissions and their intensity in China’s agricultural sector. Finally, this paper compares decoupling of China’s agricultural CO 2 emissions from agricultural output value across different regions and years. The results indicate that fertilizer, in-season rice cultivation, and cattle generated the most CO 2 emissions in the categories of agricultural production activities, farming, and livestock husbandry, respectively. The results also show that East China covered more periods of the strong decoupling of CO 2 emissions from agricultural output value between 1997 and 2014. To decrease CO 2 emissions, this paper suggests imposing a higher value-added tax on fertilizer producers, while waiving value-added tax for organic fertilizer and substituting animal manure for conventional fertilizers where possible. [ABSTRACT FROM AUTHOR]

With rapid urbanization and industrialization, the number of light-duty gasoline vehicles (LDGVs) in China has continued to grow rapidly, leading to a significant increase in traffic pollution. Therefore, it is essential to accurately calculate the emission of LDGVs for air quality monitoring and management. Fortunately, Motor Vehicle Emission Simulator (MOVES) is a sophisticated model for estimating mobile source emissions with good prediction accuracy. However, the parameters of MOVES are based on the field tests in the US, which is worth exploring whether MOVES can be applied to other countries. Hence, in this paper, we used the portable emission measurement system (PEMS) to conduct real driving emission (RDE) tests of LDGVs, aiming to explore the possibility of the MOVES application in China. Based on the field tests, we modified basic parameters in the MOVES model, but unsatisfactory prediction performance was obtained. Existing research on improving MOVES performance mainly involved new binning of operating modes, but these methods had limited improvements. Though studies have also used machine learning methods for predicting LDGV emissions, they lacked comparison and integration with the MOVES model. To further improve the prediction accuracy, we proposed a novel road vehicle emission model that integrated the machine learning method and the MOVES to predict the road-level emission rates of NO and CO 2 emissions of LDGVs. In addition, we employed the Boruta algorithm to capture the key influencing factors and promote prediction performance. The enhanced model outperformed MOVES and achieved higher R2 values. On average, the improvement for CO 2 was 0.132, and for NO, it was 0.261. This work will provide references for MOVES improvements in practical scenarios and better predict pollutant emissions for LDGVs using limited resources of field tests in cities outside the US. • Integrating engine characteristics with the MOVES model can improve model performance. • Integrating machine learning with MOVES performs well in prediction of vehicle CO 2 and NO emission. • The proposed emission model provides a possibility for calculation rather than costly an experiment in countries outside the USA. [ABSTRACT FROM AUTHOR]

The cement manufacturing industry, a resource- and energy-intensive sector, took up more than 15% of total greenhouse gas emissions in China, thus finding a clean technology option for sustainable development is essential. CO 2 curing has emerged as a promising novel method for large-scale carbon sequestration and mechanical properties improvement of cement-based composites. Currently, a body of related works is mainly investigated in the laboratory, and understandings of the behaviors of CO 2 -cured cement-based composites are still less than complete, including, 1) the CO 2 storage potential has plenty of room for improvement due to the influence mechanism of variables factors remains unclear; 2) previous evaluations were mostly based on the subsets of individual result rather than an integrated dataset; 3) whether CO 2 curing is suitable for the manufacturing process of reinforced concrete. Therefore, this paper presents a comprehensive overview covering a wide range of parameters as well as fabrication, mechanical (compressive strength), and environmental (CO 2 uptake value) performances on the basis of a correct understanding of the differences between active and passive carbonation reactions. Notably, the influences of critical factors, including those less understood, e.g., types of curing setup (flow-able, enclosed, and others), components of binder, and aggregate/binder ratio, are also analyzed and the corresponding mechanisms discussed to achieve satisfied curing efficiency. Besides, corrosion-related challenges are also be pointed out to convince the widespread acceptance of this technology. Finally, based on this paper, limitations of existing research are identified and future scope on CO 2 curing regime is proposed. • 170 studies related to CO 2 /carbonation-cured cement-based composites are analyzed. • The differences between active/passive-carbonation together with reaction mechanisms are expounded. • Fabrication and influence factors on engineering and environmental properties are systematically reviewed. • CO 2 -cured cement-based composites exhibit excellent resistance to aggressive conditions. • The challenges and opportunities in the CO 2 curing method are innovatively discussed. [ABSTRACT FROM AUTHOR]

As the basic sector providing basic service and promoting economy development, the increment demand of transport sector has brought much more pressure on the environment. Beijing-Tianjin-Hebei region is the representative region of the advanced region of China and it is significant to analyze how to achieve the low-carbon transport development in Beijing-Tianjin-Hebei region, meanwhile provide reference of green development for other regions. Using the panel data from 1995 to 2016, the paper analyses the driving factor of carbon dioxide emissions from transport sector with two different analytical methods. The results of LMDI show that transportation energy intensity and economic effect is the main factor increasing the carbon dioxide emissions and the contributing factors to the carbon dioxide emissions reduction in the transport sector are the energy structure effect, the freight turnover of unit industrial output effect and the industrialization effect. In different subclasses divided by different threshold variables, industrialization has the positive impact while the coefficients vary, which indicates that appropriate development policies should be formulated in light of the development characteristics of different regions. [ABSTRACT FROM AUTHOR]

• A high spatial resolution CO 2 emissions inventory of 280 Chinese cities was compiled. • Three methods were compared to evaluate the carbon efficiency of Chinese cities. • The best and worst-performing cities were consistent regardless of different methods. • Top-ranking cities were located in the coastal regions of China. • Lagging-behind cities were located in the central and western regions of China. Comprehensive and accurate city-level carbon dioxide emissions inventory is key to success in China's pursuit of low-carbon development. Based on a high-resolution gridded data, this paper evaluates and benchmarks the carbon emissions efficiency of 280 Chinese cities using three different methods, i.e., composite index, data envelopment analysis and stochastic frontier analysis. The comparative analysis reveals that the average carbon emissions efficiency of Chinese cities is about 70–90%, with only 9 efficient cities (3%). Although the ranking of intermediate cities varies greatly according to the method employed, the most and least carbon-efficient cities remain consistent. While the best-performing cities are found in the coastal regions, the worst-performing cities are located in the central and western regions, which suggests an imbalanced low-carbon development in China. Guided by the results, local governments are encouraged to compete and learn from similar ranking benchmarks in a new regime of "Top Runner City". Finally, the scores of carbon emissions efficiency can provide a scientific basis for the bottom-up allocation of carbon emissions rights to boost the development of the nationwide carbon market in China. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • We incorporate a variety of principles and indicators into an improved ZSG-DEA model. • We conduct a multi-criteria allocation of China's CEA by 2030 to provincial shares. • We measure the total and per capita space for carbon emissions by province. • All provinces reach the DEA frontier with different CEA ranging from 4.21 to 16.77 Gt. • Differentiated provincial reduction policies are the key to achieving China's INDCs. Abstract Accelerating global warming has suggested the importance of controlling greenhouse gas emissions associated with human activities. In striving to fulfill the Paris Agreement, China has announced its Intended Nationally Determined Contributions (INDCs) aimed at reducing its carbon dioxide (CO 2) emission intensity by 60–65% in 2030 against the level of 2005. However, China's INDCs cannot be fulfilled without formulating appropriate schemes for the allocation of carbon emission allowance (CEA) at sub-national scales. To help close the gap in our knowledge, this paper starts with measuring the overall CEA of China by 2030, and then proposes a science-based scheme for CEA allocation by developing an improved zero sum gains-data envelopment analysis (ZSG-DEA) model. It demonstrates that the final CEA of some northern provinces can be cut down as compared to their initial shares and, conversely, most southern provinces experience an increase in their CEA. Comparing the final share of CEA by province with current carbon emissions, we observe that provinces with abundant energy reserves, such as Shanxi, Inner Mongolia and Shaanxi, tend to be operating in a state of overshoot in terms of space for carbon emissions (SCE). In contrast, there remains SCE when it comes to Guangdong, Hunan, Fujian, etc. The remaining provinces, such as Heilongjiang, Hebei and Ningxia, are close to the break-even point. In view of the differing SCE of individual provinces, common but differentiated policies for CO 2 emission control would be the key to achieving China's INDCs. The research findings lay a scientific basis for the Chinese government to make its INDCs come true through inter-provincial collaboration on emission reduction, but also serve as a reference for fueling further scientific discussions and development of schemes for the allocation of responsibility for carbon emissions at multiple scales within and beyond China. [ABSTRACT FROM AUTHOR]

Applying a parameterized directional distance function approach, this paper estimates the regional eco-efficiency and pollutants' marginal abatement costs in China based on provincial panel data covering the years 2003–2012. We find that China could potentially save capital, labor, land, energy and water by 18.07%, 11.47%, 11.20%, 12.28% and 11.19%, and reduce emissions of carbon dioxide (CO 2 ), household refuse and waste water by 11.75%, 11.02% and 11.46%, respectively, on condition that all provinces produced fully efficiently, The south and east coastal areas were the most eco-efficient, while the middle Yangtze River and southwest areas performed relatively poor. For the whole country, the average shadow prices of CO 2 , household refuse and waste water were 717.27 Yuan/tonne, 42,936.98 Yuan/tonne and 306.65 Yuan/tonne, respectively. The shadow price of CO 2 revealed significant regional disparities and that of household refuse showed a rapid increase throughout the study period. Our estimates suggest that policymakers should take measures to avoid ineffective capital investment and improve economic output efficiency in inland provinces, especially in the middle Yangtze River, northwest and southwest areas, and facilitate technological cooperation between developed and undeveloped areas. The regional heterogeneity and flexible price mechanism of various pollutants should be taken into consideration when making the reduction allocations among different areas. [ABSTRACT FROM AUTHOR]

Forecasting CO 2 emissions in China always has been of great significance as it could help the government to improve energy policies and plans. To this end, a novel grey multivariable model is designed in this paper. Compared with the conventional grey multivariable model, which has certain drawbacks of inaccurate prediction and poor adaptability that restrict their applications in practical cases, the proposed model can make three improvements: first, an optimized grey model having a modified background value is proposed to predict the trends of the driving variables. Second, the novel grey multivariable model is established, combined with the changing trends of driving variables. Third, the adjustment coefficient in the new model is optimized to obtain optimal values for the time response function. To demonstrate its efficacy, the proposed model is employed to reproduce and predict the CO 2 emissions from fuel combustion compared with four benchmark models—the results show that the new model yields more accurate forecasting results than the competing models. Eventually, the new model will be used to quantify future Chinese CO 2 emissions from fuel combustion from 2014 to 2020, and the forecasted results can provide a solid basis for formulating environmental policies and energy consumption plans. [ABSTRACT FROM AUTHOR]

The issue of climate change has become an increasing concern for the international community. At the same time, climate change and, particularly, global warming affects the amount of energy required in China and the structure of this demand, thereby influencing the amount of CO 2 (carbon dioxide) emissions produced. To investigate the possible influence of climate change on China's CO 2 emissions, this paper utilizes the degree-day method to calculate the heating degree days (HDD) and cooling degree days (CDD) in 29 provinces in China from 1995 to 2011. A series of appropriate econometric models are subsequently estimated to measure the impact of climate change on CO 2 emissions per capita. To enhance the explanatory power of the estimation results, several indicators, such as income per capita, industry structure, urbanization rate and population density, are incorporated in the estimation equations as control variables. The estimation results indicate that the feedback effect of climate change on China's carbon emissions is statistically significant but not large in magnitude. During the sample period between 1995 and 2011, approximately 1.687% of China's increased total CO 2 emissions could be attributed to climate change. Moreover, the impacts of climate change on different regions of China are notably different. For example, the influence of HDD on CO 2 emissions per capita are most significant in the middle and southern regions, while the impacts of CDD are most significant in the eastern and northern regions. However, there is no obvious evidence that climate change has affected CO 2 emissions in the western region. [ABSTRACT FROM AUTHOR]

Electric rubber tire container gantry cranes (ERTGs) have already been widely used to replace rubber tire container gantry cranes (RTGs) in many ports of the world, especially in China. ERTGs can reduce carbon dioxide emissions by shifting energy demand from diesel to electricity (energy replacement). It takes almost 6–12 months to change a RTG to an ERTG, and the changed yard cranes cannot work during the replacement phase due to the mechanical reformation and electrical power system construction etc. Therefore, the yard crane network will generate bottlenecks in the container flow and influence the service level when energy replacement happens. This paper focuses on the problem of allocating limited resources for yard cranes to reduce the carbon emissions. The main challenges are how to solve the energy replacement problem at a network level and how to cope with the high uncertainties in the container terminal transportation network. Therefore, we model the energy replacement problem with the purpose of minimizing the carbon emissions by combining an allocation resource mathematical model and a simulation model of the whole transportation network together. The first stage of the energy replacement problem is to make energy replacement decisions each year, while the second stage is to evaluate the value of a seaport's service level based on the realized decisions by running the simulation model. However, the service level indicator is a random variable dependent on the decisions in the mathematical model, which should be controlled to make the seaport work normally at a network level. As an example, the optimization and simulation procedures are applied to a major container terminal in China. The proposed model is general and can be applied to the energy replacement problem of any other seaport. [ABSTRACT FROM AUTHOR]

• Two new indicators are proposed to assess the impact of sector CO 2 reduction on other sectors. • These indicators consider the cascading effect between sectors in the industrial chain. • Compared with existing indicators, new indicators can provide more information for policy. • Electricity and hot water production and supply sector has a major impact on China's CO 2 emissions. To mitigate environmental pressure, many studies have calculated the CO 2 emissions of a sector from the perspectives of production and consumption. However, determining a sector's CO 2 reduction tasks based on these two indicators may underestimate the contribution of that sector to CO 2 reductions in the entire economic system. The total CO 2 emission reduction in the entire economic system cannot be regarded as a simple sum of CO 2 emission reductions in various sectors. The situation that the reduction of CO 2 emissions in one sector can promote the reduction of CO 2 emissions in other sectors through a series of chain reactions in the industrial chain needs to be considered. Therefore, the purpose of this paper is to develop new indicators to assess the impact of sectoral CO 2 reduction in the industrial chain, that is, when CO 2 emissions are reduced in one sector, how much it promotes to the reductions in other sectors. We take China as a case and gain additional insights that are not available from existing indicators. The results reveal when the CO 2 emissions of the Electricity and hot water production and supply sector change by 10%, its PCIC-CE and CCIC-CE are 4.13% and 3.83%, respectively. This indicate that the direct reduction of CO 2 emissions in the sector has an additional impact on the CO 2 emissions of the entire economic system. Hence, the new environmental indicators proposed in this paper can complement the existing indicators and guide sector-level environmental pressure mitigation strategies from a holistic perspective. [ABSTRACT FROM AUTHOR]

• The paper analyze the drivers of the per-capita CO 2 emissions inequality in building sector across China. • Economic growth helps to narrow regional disparities for residential buildings. • Energy intensity is the primary contributor to emissions inequality. • This paper highlights the importance of per-capita CO 2 emissions in formulating carbon peak planning. There are significant regional differences in CO 2 emissions in China's building sector. Analyzing and understanding this geographic inequality and its drivers is crucial for balanced regional development and greenhouse gas (GHG) emissions reduction. In this paper, we estimated the CO 2 emissions of China's building sector at the provincial level and then calculated the Theil Index of per-capita CO 2 emissions generated from different building types. Based on these results, a Kaya identity was applied to analyze the drivers of the inequality in CO 2 emissions across China. We found that the inequality index of the different types of buildings makes a significant difference. In general, the Theil Index for public buildings and urban buildings is higher than that for rural buildings. Income, energy intensity and energy mix are the principal drivers of regional disparity of per-capita emissions. Economic growth helps to narrow regional disparities for residential buildings, but its contribution is not significant for public buildings. For all building types, energy intensity is the primary contributor to emissions inequality, and the imbalanced implementation of energy efficiency policies is a leading factor. Energy mix plays an increasing role in the regional disparities of per-capita CO 2 emissions, especially for rural buildings. Reducing these regional disparities is crucial to China's goal of achieving peak GHG emissions and reaching carbon neutrality. This paper highlights the importance of per-capita CO 2 emissions in formulating carbon peak planning, allocating regional emissions reduction targets, formulating building energy policies and allocating low-carbon resources. [ABSTRACT FROM AUTHOR]

• An improved method to evaluate the marginal abatement cost of CO 2 in China. • The economic proximity is introduced to deal with the heterogeneity. • A smaller inefficiency, 2.551%, is estimated by the improved method. • China's average marginal CO 2 abatement cost is 797.79 CNY/ton with a growing trend. • The optimal quota allocation can save approximately 797.793 billion CNY. Marginal emission abatement costs play an important role in the emission trading market and in the allocation of emission reduction allowances. The traditional methods for estimating marginal emission abatement costs do not account for technological heterogeneity, which leads to biased results. To solve this problem, an improved method that combines the clustering method with a parametric output directional distance function is proposed in this paper. This method integrates the economic proximity of each examined province into its assessment of the environmental production technology of the province and takes multiple pollutants (CO 2 , SO 2 and NO X) into consideration. Based on this method, in this paper, the environmental performance of 30 provinces in China from 2006 to 2017 is measured, the marginal emission abatement cost of CO 2 is estimated, and a nonlinear programming method is used to study the optimal allocation of emission reduction in China. The results indicate the following: First, categorizing the provinces according to their economic proximity results in groups that differ greatly from geographically based groups. Second, the average inefficiency of these 30 Chinese provinces is 2.551%, which is less than that estimated by the methods that do not consider heterogeneity. Third, China's average marginal CO 2 abatement cost is 797.79 CNY/ton, and it exhibits a growing trend. Finally, compared to the grandfathering rule, the optimal quota allocation proposed by this paper can save approximately 797.793 billion CNY. [ABSTRACT FROM AUTHOR]

• The average carbon reduction performance increases year by year. • The policy has an immediate impact on CO 2 reduction in demonstration cities. • The policy has follow-up impact on carbon emission reduction. • Less thermal power and more research investment are the paths to policy effect. The Energy-saving and Emission Reduction Demonstration City (ESERD) Policy brings more favorable development conditions and opportunities for the cities selected, but the carbon reduction effect of the energy-saving policy is not clear which needs to be quantified and evaluated. By measuring the Total Factor/Energy Carbon Performance Index (TCPI /ECPI) of 286 prefecture-level cities in China from 2003 to 2019 and by constructing a quasi-natural experiment, this paper contributes in three aspects. (1) we are committed to a method of calculating the energy consumption and carbon emission of prefecture-level cities in China; (2) we provide evidence to the CO 2 reduction effect of the ESERD policy in a more comprehensive way; (3) we probe the paths of the policy effects. The main findings are: (1) TCPI and ECPI has been rising since 2011, the eastern cities have more outstanding achievement while the performance of the western region has been at a relatively high level during the time period of the study, and the performance of cities have diverged in recent years. (2) The policy's contribution to the demonstration cities' carbon reduction performance is significant, immediate and far-reaching, a lower share of electricity consumption due to indirectly reducing the use of coal, and higher investment in scientific research for improving the technology level of industrial development are both paths to achieve carbon emission reduction in the demonstration cities. [ABSTRACT FROM AUTHOR]

In order to fill the research gap of CO 2 -fixing cementitious materials, and to deal with China's dual-carbon goal, first to use bacteria and steel slag powder to fix CO 2. The paper using untreated steel slag powder as control group, different CO 2 -fixing steel slag powder are compared, they are CO 2 treated steel slag and bacteria-CO 2 treated steel slag. The XRF and XRD results shows that the physicochemical properties of steel slag powder with different treatments are significantly different. Because the chemical composition and particle surface properties of steel slag powder are changed in the CO 2 fixing process due to the reactions. There are calcium carbonates formed in steel slag powder when cured by CO 2 from cement kiln tail gas. The SEM images show that the surface of steel slag powder has defects. Steel slag with bacteria will produce more calcium carbonates and its surface has more defects. Therefore, it will have an impact on the cement-based material fresh paste workability and hardened paste properties. The results of the fresh paste workability show that, the surface defects of steel slag powder have an adverse impact on the workability, because the defects increase the internal friction between particles. The results of hardened paste strength show that the cement-based materials mixed with SSLP-BC has the better mechanical properties. The XRD, FTIR, SEM, 1H NMR and X-CT results of hardened paste show that, the microstructure of cement-based materials mixed with SSLP-BC is denser. This may be caused by the nucleation of bacteria and calcium carbonate. Moreover, calcium carbonate may play an important role in hydration process, there is carboaluminates formed in the hardened paste that containing calcium carbonate, and it is beneficial for mechanical properties. Therefore, steel slag after bacteria-CO 2 treated can used as SCM, it has better social and environmental benefits. [ABSTRACT FROM AUTHOR]

Fossil fuels are major feedstock for industrial processes in the word. However, processing fossil fuels emits a large amount of CO 2 giving a serious environmental impact. Conventional analysis of this impact is to quantify Global Warming Potential by using CO 2 equivalent, but not on quantitatively energetic and economic metrics. This cannot measure a real cost of ecological goods and services, e.g. carbon sequestration, biogeochemical cycles, mineral and fossil resources. To address this issue, this paper introduces energetic and economic penalties. They are inspired by circulation of CO 2 between industrial and ecological systems and defined as the additional energetic and economic costs for closing the CO 2 loop by using ecological goods and services. These additional costs are considered as penalties. The carbon footprint and life cycle exergy/cost rate are applied to model the penalties. These models consider regional condition, for they include some regional ecological factors. Coal-to-olefins projects in different regions of China are used as case studies. Their energetic and economic penalties are calculated. Results show that olefins productions in Gansu, Ningxia, and Sinkiang suffer from the highest penalties. For economic penalties, they are higher than 2400 RMB/t olefins. Productions in Inner Mongolia and Shanxi have the penalties in middle range, 1235 RMB/t olefins and 1656 RMB/t olefins. Productions in other regions pay much lower penalties, around 1000 RMB/t olefins. [ABSTRACT FROM AUTHOR]

Understanding how grazing exclusion affects carbon exchange by the plant and soil features is essential for clarifying the contribution of grassland management to the carbon budget. This paper studied effects of grazing exclusion on soil respiration, ecosystem respiration, net ecosystem carbon exchange, plant and soil characterizes for two growing-seasons (2012 and 2013) in a steppe grassland on the Loess Plateau, China. Grazing exclusion markedly increased soil respiration, ecosystem respiration and net ecosystem exchange about 0.36, 0.65 and −0.10 g C m −2 d −1 , respectively. Grazing exclusion enhanced aboveground biomass, belowground biomass and cover, and which were positive correlated with CO 2 flux. Soil water content, rather than soil temperature, was the major environmental factor controlling soil respiration and ecosystem respiration by partial least-squares regression. The ratios of soil respiration, ecosystem respiration and net ecosystem exchange to atmospheric CO 2 assimilated by photosynthesis at fenced grassland were similarly with them at grazed grassland. Results suggested that grazing exclusion was a positive management practice to help maintain or increase carbon stocks in a steppe grassland on the Loess Plateau. [ABSTRACT FROM AUTHOR]

Understanding the causes of growing carbon transfers between developing countries is likely to be the first step in their mitigation. With this in mind, the current paper uses multi-regional input-output analysis to investigate CO 2 emissions and value-added embodied in China-Brazil trade. We propose the use of value-added exports, rather than gross exports, to more accurately estimate the economic benefits of trade. We find enormous increases in both CO 2 emissions and value-added embodied in exports for China and Brazil between 2000 and 2014. During this period, China's position as a net CO 2 emissions and net value-added exporter vis-à-vis Brazil deepens. Major sources of increasing embodied CO 2 exports for China were the basic materials and electricity industries and for Brazil were the basic materials, agriculture and mining industries. Estimates of net carbon intensities reveal advantages for China in electronics and for Brazil in agriculture and mining. Structural decomposition analysis shows that the changing consumption in China and Brazil as well as the changing structure of intermediate exports from China to Brazil were important sources of increasing embodied CO 2 emissions. This latter finding was possible due to the method proposed in this paper of decomposing the production structure into the domestic, export and import production structures. In line with the key findings, various implications and emission abatement policies are discussed. [ABSTRACT FROM AUTHOR]

Rapid economic development in China have resulted in the booming demand for comfortable and fast travel mode, and promoted the rapid development of aviation industry in recent years. As an important source of greenhouse gas emissions, airlines' operational efficiency and environmental issues have been widely concerned in achieving the goal of cleaner production of aviation industry. Due to the limitations of traditional DEA approach, which known as a black box, the specific reasons for the inefficiency of airlines cannot be explored. This paper contributed to current literature by introducing the two-stage undesirable Network Slack-Based Measure (NSBM) approach to explore Chinese airlines' multi-stage efficiency: production stage and profit stage, and try to open the black boxes and further explore the characteristics and driving forces of the operational performance in China's aviation industry. Meanwhile, this paper incorporates CO 2 emissions into the calculation by combining the undesirable Slack-Based Measure (SBM) approach and measure the energy efficiency and CO 2 emission efficiency to evaluate their environmental performance on the basis of the two-stage framework. The empirical results on nine listed Chinese airlines from 2013 to 2018 showed that all airlines perform better in earning economic profits from carrying capacity, while the low production efficiency in converting production factors into carrying capacity limits the operational efficiency of Chinese airlines. The energy efficiency of Chinese airlines ranks in line with CO 2 emission efficiency, while the economic and environmental performance of low-cost airlines remain the best. Further discussion indicated that smaller private airlines tend to achieved better economic and environmental performance through low-cost operations, while the top three airlines in market share need further improvement in operational efficiency and environmental performance. The former should pay attention to the upgrading of flights to ensure a certain market share while maintaining its low-cost operation mode, and the latter needs to improve its management and cost control level to achieve clean development. Image 1 • Total efficiency of China's aviation industry is decomposed into production and profit efficiency. • A two-stage undesirable SBM-NDEA model is employed to open the black box. • The main reason for the inefficiency of China's aviation industry is the low production efficiency. • The low-cost airlines remain the best in economic and environmental performance. [ABSTRACT FROM AUTHOR]

This paper takes both value-added trade and trade-implied CO 2 emission reduction responsibility into account, which constructs a unified conceptual framework to recalculate CO 2 emission reduction responsibility from the perspective of value-added trade. This allows policymakers to trace worldwide CO 2 emissions at multiple levels of trade, production, consumption, and shared principle alongside the world trade network. This paper employs the gross export decomposition methodology and the World Input-Output Database for calculations. Firstly, compared with traditional trade statistics, measuring embedded emissions in value-added trade can deduct the double-counted terms of CO 2 emissions due to intermediate products crossing several borders repeatedly. Secondly, the worldwide inter-country CO 2 emission footprints embedded in exports, imports, and net flows of value-added trade are traced in a geographical world map. It occurs that, China, the USA, Russia, and the EU are the top four largest emitters. Thirdly, network analysis is further utilized to capture bilateral implicit CO 2 emission relationships, e.g., the EU members' environmental impacts depend on intra-regional trade within the union. Finally, a comparison is made under three burden-sharing principles based on value-added trade. The shared responsibility offers a compromise between the producer's and the consumer's principle, which is considered to be fairer and more effective. • This paper calculates trade-implied CO 2 emission reduction responsibility from the perspective of value-added trade. • A gross export decomposition model is applied to deduct double-counted terms of implicit carbon embedded in traditional trade. • The worldwide inter-country CO 2 emission footprints are visualized. • Network analysis is conducted to identify the major carbon emitters and their complex relations. • Three burden-sharing criteria are computed through the statistics of value-added trade. [ABSTRACT FROM AUTHOR]

Small and medium span bridges account for 86% of the bridges in China, and maintenance is necessary to ensure their safety and serviceability. The infrastructure sector causes substantial CO 2 emissions, and it is one of the most polluting sectors. Fly ash (FA) is often used in bridges to reduce CO 2 emissions. Moreover, the lack of temporal information is an important limitation of the life cycle CO 2 assessment of bridges. Taking the upper structure of small and medium span bridges as the research object, this paper proposes a Monte Carlo simulation-based life cycle multi-objective dynamic maintenance strategy optimization model to analyze the life-cycle carbon emissions, costs, and life cycle reliability of different preventive maintenance (PM) and essential maintenance (EM) methods of FA reinforced concrete (RC) beams. Considering the continuous effect of carbon emissions and the net present value of the cost, the time effect of carbon emissions and costs of maintenance and reinforcement at different times is analyzed. Through 50,000 simulations of the case beam, the parameter characteristics of different optimal reinforcement schemes and the relationship between the reliability, life cycle CO 2 emissions, and costs are studied. When introducing the discount rate, the essential maintenance with higher carbon emissions and costs has a marginal effect, i.e., the longer that future carbon emissions and costs occur, the smaller the net present value. The proposed method is demonstrated to be effective at supporting decision making for bridge managers. It would be helpful for identifying the effectiveness of PM and EM, selecting optimal maintenance time interval, and providing a rational estimate of the CO 2 emissions and costs of bridges. • A Multi-objective dynamic maintenance strategy optimization model is proposed. • The time effects of carbon emissions and costs are analyzed. • The parameter characteristics of the optimal maintenance of a T-beam are found. [ABSTRACT FROM AUTHOR]

A large accumulation of carbon dioxide and other greenhouse gases have caused great concern around the world. A great deal of general literature focus on the impact factors of CO 2 emissions at the national, regional and city levels. However, there is little specific guidance on regional difference in CO 2 emissions. In this paper, 30 provincial-level administrative units of China are divided into three different levels of economic development regions according to the GDP per capita from 1997 to 2012. A STIRPAT (Stochastic Impacts by Regression on Population, Affluence and Technology) model is used to examine the impact factors on energy-related CO 2 emissions, including population, economic level, technology level, urbanization level, industrialization level and foreign trade degree. The results indicate that the effect of energy intensity is the greatest in highly developed region. Nevertheless, the impact of urbanization, industry structure and foreign trade degree in under developed region is higher than the other two regions. Population and GDP per capita have greater effect on carbon emissions in developing region than the others. Finally, differentiated measures for CO 2 reductions should be adopted according to local conditions of different regions. [ABSTRACT FROM AUTHOR]

For the greenhouse gas (GHG) emissions in China, little attention has been given to CH 4 emissions and related emission mitigation. This paper presents a detailed bottom-up estimation and comparison analysis of China's CH 4 and CO 2 emissions for the first time. China's CH 4 emissions are shown with comparable importance to the CO 2 emissions at the national and regional levels. The national total CH 4 emission in 2008 amounts to 39 Tg, equivalent to about 1/8, 1/3 and 3/5 of the total CO 2 emission by the 100-year global warming potential (GWP) factor, the 20-year GWP factor and the global thermodynamic potential factor, respectively. Increasing CH 4 emissions could compromise China's efforts to mitigate its GHG emissions. In contrast to energy-dominated emission pattern for CO 2 , the major sources of China's CH 4 emissions are coal mining, enteric fermentation, rice cultivation and waste management. Meanwhile, there exists a large gap between the eastern coastal regions and the western and central inland regions in the emission magnitude and emission intensity for CH 4 and CO 2 , with different mitigation flexibilities. Reducing CH 4 emissions should be integrated into the national and regional policies for GHG emission mitigation. In some central and western regions such as Shanxi, Henan, Sichuan, Guizhou, Qinghai and Tibet, the inclusion of CH 4 emission intensity reduction can be more cost-effective than only setting a target for CO 2 emission intensity to reduce the regional GHG emission intensity. [ABSTRACT FROM AUTHOR]

With the increasing number of large and medium-sized cities and the improvement of intercity transportation infrastructure, polycentric urban network is gradually emerging. Based on the strong link between urbanization and carbon dioxide emissions has been proven, using a panel data of 23 provinces of China over the period of 1997–2013, this paper explores the impact of polycentric structure on carbon dioxide emissions. The results reveal that there is a u-shaped relationship between polycentric structure and carbon dioxide emissions, and the relationship is obviously different between coastal and inland areas. At the same time, market integration can effectively reduce carbon dioxide emissions, and there is a substitution relationship between polycentric structure and market integration. In addition, urban distance and transportation infrastructure within provinces play a significant non-linear regulating effect on the relationship between polycentric structure and carbon dioxide emissions. The conclusion of this paper provides some empirical evidence for the coordinated development of China's future regional space planning and energy emission reduction. [ABSTRACT FROM AUTHOR]

• China is a net exporter of carbon in Harvested Wood Product sectors. • Carbon emissions in China's Harvested Wood Product sectors are caused mainly by exports. • The US is China's largest importer of CO 2. • The furniture sector exports the most CO 2 among all Harvested Wood Product sectors. International trade of goods is also flows of CO 2. As a key exporter of harvested wood products (HWPs), China emits a large amount of CO 2 to meet the consumption of other countries. This article uses an MRIO model to quantify the embodied CO 2 emissions of China's HWP sectors in international trade based on the WIOD database. China's CO 2 emissions from a production perspective were 121.25 Mt, more than four times those from a consumption perspective. China was a net exporter for embodied CO 2 in HWP sectors, while the US was China's largest importer. In addition, the furniture sector exported more embodied CO 2 by international trade than those from the wood and paper sectors. Based on the unbalances of exports and imports, establishing a common international standard to share the responsibility for CO 2 emissions is of great urgency in HWP sectors. This article facilitates promoting CO 2 emission reduction in HWP sectors and references China's future participation in international trade and environmental negotiations. [ABSTRACT FROM AUTHOR]

The development of China's highway infrastructure has led to a rapid increase in carbon dioxide (CO 2) emissions while facilitating social and economic development. This paper introduces highway mileage and CO 2 emissions into the traditional production density model, using agglomeration as a mediating variable, to theoretically discuss the path through which highway infrastructure influences CO 2 emissions. We then use the spatial Durbin model (SDM) to verify the explanatory power of the expanded production density model based on panel data of China's 278 cities from 2003 to 2016. Empirical results indicate that (1) there is an inverted U-shaped relationship between highway infrastructure and CO 2 emissions in both local and peripheral cities; (2) highway infrastructure affects local CO 2 emissions through the agglomeration pathway but impacts CO 2 emissions in peripheral cities mainly through the spatial spillover effect of highway infrastructure; and (3) the U-shaped impact of highway infrastructure on CO 2 emissions in western China is diametrically opposed to the results for the east, the central region and the total sample. Therefore, China needs to fully consider the environmental effects of agglomeration to formulate a global emission reduction strategy when building highway infrastructure. Moreover, strategies based on the different stages of highway infrastructure development should be enacted and should be part of a spatially synergistic joint emission reduction mechanism while considering the characteristics of regional development. • The study extends the production density model and verifies the explanatory power. • The spatial correlation between variables is tested by the spatial Durbin model. • Regional heterogeneity is discussed, and the reasons for this are analysed. • The results are corrected using GS2SLS with slope as an instrumental variable. • Related policy recommendations are made for low carbon development in China. [ABSTRACT FROM AUTHOR]

Cities consume large amounts of fossil fuels and this results in significant increase of global anthropogenic greenhouse gases. Using city-level carbon dioxide emission data from Shijiazhuang, a traditional heavy manufacturing city and one of the key cities in Jing-Jin-Ji urban agglomeration in Northern China, this paper employs logarithmic mean Divisia index decomposition method (LMDI) to explore the influence of energy intensity, consumption structure, industry structure, per capita Gross Domestic Product (GDP), and population on Shijiazhuang's total carbon dioxide emissions from 2005 to 2016. The LMDI method is further extended to analyze the impacts of above factors at the industry-segment level. This paper finds that the reduction of energy intensity is the major contributor of decreasing carbon dioxide emissions in Shijiazhuang, whereas the growth of per capita GDP is the main driving force for emission accretion. The dominant industrial segments contributing to increasing emissions in Shijiazhuang City from 2005 to 2016, have changed from CMD (coal mining and dressing), EPSH (electric power, steam and hot water production and supply) to SPFM (smelting and pressing of ferrous metals) and PPC (petroleum processing and coking). The CMD industrial segment shows a significant carbon reducing effort and indicates a strong decoupling status. However, the SPFM and PPC respectively show expansive negative decoupling and weak decoupling status, enlightening a change in the policy focus when Shijiazhuang formulates its emission-reduction plans in the future. This study provides important policy insights for the heavy manufacturing cities in other countries with similar industrial structure, as the industry-based carbon mitigation policies should always be adjusted in different stages of the cities' development according to the change of carbon emission driving industries. [ABSTRACT FROM AUTHOR]

• A LEN CO 2 emission estimation model was constructed based on land use data, enhanced vegetation index and night light data. • The distributions of urban, industrial and rural CO 2 emissions in China were estimated respectively. • The spatial and temporal variations were analyzed. • The CO 2 emissions estimated by using three different models were compared. It is difficult to accurately estimate the spatial distribution of carbon dioxide (CO 2) at the grid scale because of the lack of city-level statistical data. In this paper, CO 2 emission regions were devided into urban area, industrial area and rural area in order to accurately calculate CO 2 emissions. In addition, a more accurate calculation model for energy-related CO 2 emissions was proposed through integrating nighttime light datasets and land use data. The maps of estimated CO 2 emissions in different regions were compared and examined through using spatial dependence and grid overlay methods to understand the spatial distribution characteristics and spatiotemporal dynamics of CO 2 emissions in China. The results showed that the model proposed in this study was appropriate and reliable for CO 2 emissions not only in urban and rural areas but also in industrial areas. CO 2 emissions in China were mainly concentrated in the coastal areas and the northern area, and the amount of carbon emissions increased rapidly from 2000 to 2018 in the Middle Yellow River. These results could improve the understanding of regional discrepancies of spatiotemporal CO 2 emission dynamics at gride scale, and provide a scientific reference for the formulation of energy conservation and emission reduction policies by the local government. [ABSTRACT FROM AUTHOR]

Abstract: This paper uses nonparametric efficiency analysis technique to estimate the energy efficiency, potential emission reductions and marginal abatement costs of energy-related CO2 emissions in China. We employ a non-radial slacks-based data envelopment analysis (DEA) model for estimating the potential reductions and efficiency of CO2 emissions for China. The dual model of the slacks-based DEA model is then used to estimate the marginal abatement costs of CO2 emissions. An empirical study based on China’s panel data (2001–2010) is carried out and some policy implications are also discussed. [Copyright &y& Elsevier]

Abstract: Reducing environmental pressure is a major concern for China but despite the improvements in energy efficiency, its gross carbon dioxide (CO2) emissions have maintained an upward trend, consistent with the Jevons Paradox. A fundamental shift is thus needed at all levels, including the household. This paper explores the embedded carbon footprint (ECF) of Chinese urban households associated with activities, such as food, personal transport, communications, education, recreation, health and hygiene. It uses an input–output model for carbon emissions and 2003–2009 urban household data. The results show that the total ECF emission intensity increases when an individual''s consumption is higher than 10,000 Yuan (¥). Structural changes are further observed with consumption expenditure above ¥10,000: food, clothing and other survival-oriented emissions intensities as well as education, health and development-oriented emissions intensities reduce; transport, recreation, housing and enjoyment-oriented emissions intensities increase or remain stable and the total emissions intensity increases. Currently per capita consumption expenditure of Chinese urban residents exceeds ¥10,000 and as income continues to rise, China will remain on a high-carbon track. There is a need for better policies, management and behavioural change and the study provides some policy suggestions, including a carbon quota system to guide individual consumption. [Copyright &y& Elsevier]

Abstract: Civil aviation in China has developed rapidly in recent years, and the effects of civil aviation emissions on the atmospheric environment should not be neglected. The establishment of emission inventories of atmospheric pollutants from civil aviation contributes to related policy formation and pollution control. According to the 2010’s China flight schedules, aircraft/engine combination information and revised emission indices from the International Civil Aviation Organization emission data bank based on meteorological data, the fuel consumption and HC, CO, NO x , CO2, SO2 emissions from domestic flights of civil aviation in China (excluding Taiwan Province) in 2010 are estimated in this paper. The results show that fuel consumption in 2010 on domestic flights in China is 12.12 million tons (metric tons), HC, CO, NO x , CO2 and SO2 emissions are 4600 tons, 39,700 tons, 154,100 tons, 38.21 million tons and 9700 tons, respectively. The fuel consumption and pollutant emissions of China Southern Airline are responsible for the largest national proportion of each, accounting for 27% and 25–28%, respectively. [Copyright &y& Elsevier]

Abstract: Biomass, a renewable, sustainable and carbon dioxide neutral resource, has received widespread attention in the energy market as an alternative to fossil fuels. Thermal–chemical conversion of biomass to produce biofuels is a promising technology with many commercial applications. This paper reviewed the state-of-the-art research and development of thermal–chemical conversion of biomass in China with a special focus on gasification, pyrolysis, and catalytic transformation technologies. The advantages and disadvantages, potential of future applications, and challenges related to these technologies are discussed. Conclusively, these transformation technologies for the second-generation biofuels with using non-edible lignocellulosic biomass as feedstocks show prosperous perspective for commercial applications in near future. [Copyright &y& Elsevier]

Abstract: This paper establishes several efficiency models based on environmental production technology, which are capable of integrating undesirable outputs into efficiency evaluation framework. With the proposed efficiency models, we estimate the environmental efficiency, economic efficiency, economic-environmental efficiency and two-stage efficiency of different provinces in China by considering carbon dioxide (CO2) emissions. Our empirical results show that the environmental and economic efficiency of China are generally low and there exist comparatively large differences in different areas. The average proportion for simultaneously reducing CO2 emissions and increasing GDP is about 36–40%. When desirable outputs are adjusted to the optimal level, some provinces have still the possibility to further reduce CO2 emissions. About half of the provinces is found to be in the status of high incoordination between environment and economy. [Copyright &y& Elsevier]

Abstract: This paper establishes a carbon capture and storage (CCS) investment evaluation model based on real options theory considering uncertainties from the existing thermal power generating cost, carbon price, thermal power with CCS generating cost, and investment in CCS technology deployment. The model aims to evaluate the value of the cost saving effect and amount of CO2 emission reduction through investing in newly-built thermal power with CCS technology to replace existing thermal power in a given period from the perspective of power generation enterprises. The model is solved by the Least Squares Monte Carlo (LSM) method. Since the model could be used as a policy analysis tool, China is taken as a case study to evaluate the effects of regulations on CCS investment through scenario analysis. The findings show that the current investment risk of CCS is high, climate policy having the greatest impact on CCS development. Thus, there is an important trade off for policy makers between reducing greenhouse gas emissions and protecting the interests of power generation enterprises. The research presented would be useful for CCS technology evaluation and related policy-making. [Copyright &y& Elsevier]

Abstract: This paper examines the driving forces for reducing China’s CO2 emission intensity between 1998 and 2008, utilizing the logarithmic mean divisia index (LMDI) technique. By first grouping the CO2 emissions into two categories, those arising from activities related to the electric power industry and those from other sources, emission intensity is further broken down into the effects of the CO2 emission coefficient, energy intensity of power generation, power generation and consumption ratio, electricity intensity of the gross domestic product (GDP), provincial structural change, and the energy intensity of the GDP for other activities. The decomposition results show that improvements in the energy intensity of power generation, electricity intensity of GDP, and energy intensity of GDP for other activities were mainly responsible for the success in reducing China’s CO2 emission intensity and that activities related to the electric power industry played a key role. It is also revealed that performance varied significantly at the individual province level. The provinces with higher emission levels contributed the most to China’s improvements in CO2 emission intensity. [Copyright &y& Elsevier]

Abstract: This paper uses multivariate co-integration Granger causality tests to investigate the correlations between carbon dioxide emissions, energy consumption and economic growth in China. Some researchers have argued that the adoption of a reduction in carbon dioxide emissions and energy consumption as a long term policy goal will result in a closed-form relationship, to the detriment of the economy. Therefore, a perspective that can make allowances for the fact that the exclusive pursuit of economic growth will increase energy consumption and CO2 emissions is required; to the extent that such growth will have adverse effects with regard to global climate change. [ABSTRACT FROM AUTHOR]

To analyze and understand decarbonizing economic development in China, this paper undertakes a structural decomposition analysis of the historical change in energy-related carbon intensity in China between 1992 and 2006. The results show that the energy-related carbon intensity in China decreased by about three-fourths between 1992 and 2006 and reduced carbon emissions by about two billion tons. The decline in the energy-related carbon intensity was mainly caused by changes in production pattern, especially changes in energy intensity within each sector between 1992 and 2002. However, the most important driving force of carbon intensity from 2002¿2006 was not the energy intensity within each sector but the input mix. On the other hand, changes in demand pattern pushed up the carbon intensity. To further decarbonize the economy in the future, it is important for China to further enforce policies on shaping the production pattern, such as reducing energy intensity, and pay more attention to increasing the sustainability of the demand pattern at the same time. [Copyright &y& Elsevier]

In order to ensure the implementation of the emission trading scheme (ETS), the allocation of CO 2 emission quotas in China's provinces is of significant importance. Unlike previous studies that allocated CO 2 emission quotas directly to Chinese provinces, we propose a two-step allocation scheme of "country to region" and "region to province" to formulate the provincial CO 2 emission quotas allocation. In the first step, considering the regional coordination development, the Shapley value method is used to assign the CO 2 emission quotas to China's eastern, central, and western regions by simulating the regional collaborative abatement. In the second step, we use the entropy method to obtain the initial CO 2 emission quotas for each province combining the principles of fairness, efficiency, feasibility, and sustainability. Then, a zero-sum gains data envelopment analysis (ZSG-DEA) model is applied to evaluate initial allocation efficiency and reallocate the CO 2 emission quotas to realize efficiency optimization within the region. The results show that the eastern region obtains the largest CO 2 emission quotas, followed by central and western regions. The energy-abundant and economic-prosperous provinces, such as Shandong, Hebei, Inner Mongolia, and Xinjiang, face great pressures on CO 2 reduction. Compared with existing literature, the proposed scheme's regional allocation results are more balanced, which will narrow the gaps of regional economic development. Since the emission reduction pressure varies in provinces, developing differentiated policies is critical to realizing China's reduction targets. By considering regional fairness, this paper provides a reference for allocating CO 2 emission quota among provinces to improve adaptability to the current conditions of China. [Display omitted] • The Shapley value method was used to allocate CO 2 emission quotas among China's regions. • We use the entropy method to allocate CO 2 emission quotas to province within each region. • A ZSG-DEA model was used to redistribute the CO 2 emission quotas across provinces. • The eastern China has the largest share of CO 2 emission quotas, followed by central and western. • Energy-abundant and economic-prosperous provinces have more pressures on CO 2 abatement. [ABSTRACT FROM AUTHOR]

[Display omitted] • Clean energy transitions based on the circular economy (CE) are analysed for a town in China. • This could reduce energy use, CO 2 emissions and PM 2.5 emissions compared to the BAU scenario. • COVID pandemic is a new opportunity to introduce circular economy measures. • Circular economy measures could accelerate clean energy transitions. This paper models the energy and emissions scenarios for a circular economy based clean energy transitions in a 140,000-population town in China, taking into account the new situation encountered by the COVID-19 pandemic. The modelled scenarios propose new clean energy transition roadmaps towards a sustainable urban system through the implementation of circular economy strategies. This is represented by the cascading use of industrial excess heat to form symbiosis between factories and to cover the growing building heat demand, as well as by the electrification of the transport sector and reusing the batteries for a second life as energy storage devices. The results show that for a circular economy scenario, during 2020–2040, an accumulated saving of 7.1 Mtoe final energy use (34%), a decline in 14.5 Mt CO 2 emissions (40%) and 592 t PM 2.5 emissions (43%) could be achieved compared with the business-as-usual scenario. The outcomes of the circular economy strategies are at least 7% better than the new policy scenario which simply has energy efficiency improvements. The outbreak of the COVID-19 tremendously impacts the socio-economic activities in the town. If taking the pandemic as an opportunity to enhance the circular economy, by 2040, compared with the scenario without introducing circular economy measures, the extra avoided final energy use, CO 2 emissions and PM 2.5 emissions could be 1.6 Mtoe (8%), 3.8 Mt (11%) and 229 t (17%) respectively. [ABSTRACT FROM AUTHOR]

An integrated approach is proposed in this paper to incorporate the group heterogeneity into the framework of natural disposability and managerial disposability, which allows evaluating the CO 2 emission performance under different mitigation strategies (scale-oriented strategy and innovation-oriented strategy). It is able to deal with the intertemporal incomparability when adopting a global technology. In the empirical study, we categorized China's 27 manufacturing sectors into five groups and evaluated their emission performance under different mitigation strategies during 2003–2016. According to the empirical results, we found that there is still much potential (about 70%–80%) for improving the CO 2 emission performance considering the entire manufacturing industry. From the perspective of different groups, the global technologies/innovators group shows the highest emission efficiency, while the energy-/resource-intensive commodities' group performed the worst. Besides, different sectors showed significant technology heterogeneity. Finally, the desirable CO 2 mitigation strategies varied with the different groups. For the labor-intensive tradables' group, we found that the desirable strategy is to decrease the input of energy and other production factors, i.e. scale-oriented strategy. For the regional processing group, the innovation-oriented strategy is more efficient. • Modified global meta-frontier non-radial DDF approach is proposed. • Group heterogeneity is incorporated in natural/managerial disposability framework. • CO 2 emissions performance for China's manufacturing sectors is measured. • Global technologies/innovators group performs best, while energy-/resource-intensive commodities group performs worst. • Desirable mitigation strategies varies with respect to technology heterogeneity of different groups. [ABSTRACT FROM AUTHOR]

Timely maintenance is crucial to ensure the long-term performance of asphalt pavements. Due to the large amount of greenhouse gases (GHG) emitted during construction, it is important to evaluate the environmental impacts of various maintenance technologies, so that the whole life impacts of asphalt pavements can be understood and reduced. This paper estimated the GHG emissions of 16 maintenance technologies in the four categories of surface seal or coating system, thin overlay system, hot recycling system and cold recycling system by using life cycle assessment (LCA), and identified the technologies and the combination of them that have the least GHG emissions. In order to compare the maintenance technologies on a level-playing basis, this study designed maintenance scenarios for the entire life cycle of the pavement, and established a system boundary where all maintenance scenarios are compared transparently for a defined functional unit. Results show that, among the preventive maintenance technologies, micro-surface and fog seal have the lowest GHG emissions. In order to meet the same performance requirements of highway pavement, cold recycling with extra overlay will generate more than twice GHG emissions that of hot recycling. Increasing the frequency of preventive maintenance, and reducing the occurrence of corrective maintenance can reduce GHGs emissions by 30%–45% in pavement life. Reasonably designed maintenance plan for the entire life cycle can significantly reduce the GHG emissions of asphalt pavements. • The CO 2 footprint of sixteen asphalt pavement maintenance technologies was analyzed. • Micro-surface and fog seal have the lowest GHG emissions. • Cold recycling with extra overlay will generate more than twice GHG emissions that of hot recycling. • Increasing the frequency of preventive maintenance can reduce the GHG emissions. [ABSTRACT FROM AUTHOR]

In China's low-carbon development progress, industrial sectors play a crucial role in reducing CO 2 emissions and maintaining economic growth targets. Because the Chinese government is promoting industrial structure transformation for "high-quality economic development," the dominant CO 2 emitters have changed in recent years. It is important to identify the trend evolution of industrial CO 2 emitters and implement targeted measures and policies for CO 2 emission control at the sector level. In this paper, a hybrid input–output model is adopted to assess the situation and trend of sectoral CO 2 emissions from 2002 to 2017 in China. Demand-side drivers of sectorial embodied CO 2 emissions are discussed. Based on the embodied CO 2 emission decomposition of 27 sectors, a CO 2 emission evaluation index is defined for CO 2 emission ranking and key sectors for embodied CO 2 emissions are identified. For the key CO 2 emitters, we provide targeted policy suggestions for CO 2 emission mitigation from the perspective of trend evolution and index ranking. The results indicate the following. (1) 2015 is a turning point for China's CO 2 emission mitigation progress, because the previously increasing embodied CO 2 begins to decrease from 2015 to 2017. (2) Although the Construction sector stimulates a large amount of CO 2 emissions at present, the major driving forces of CO 2 emissions have gradually changed from infrastructure construction to the increasing demand of consumer goods, service industry, and export of technology-intensive products. (3) The CO 2 emission intensity of the Electric Power and Heat Supply sector has increased, and promotion of renewable energy consumption is urgently needed. (4) From the demand-driven aspect, tertiary industry has greater CO 2 emission potential than heavy industry. • A turning point of embodied carbon dioxide of China appears in 2015. • Most sectors have reached the peak of embodied carbon dioxide by 2015. • Construction, Other Service Industry and Manufacture of Machinery are the top three embodied carbon dioxide emitters. • Electric Power and Heat Supply sector should be concerned for high embodied carbon dioxide intensity. • Sectors with great carbon dioxide emission potential change towards tertiary and high-tech industries. [ABSTRACT FROM AUTHOR]

(a) Historical carbon emission mitigation of the residential building sector and (b) emission benchmarks of the future residential building sector in China. • Carbon mitigation of the residential building sector in 2000–2015 is 1.817 (±0.643) BtCO 2. • Residential building will achieve its emission peak in 2037 (±4) at 1.419 (±0.081) BtCO 2. • Floor space per capita and energy intensity are determining in the uncertainty of emission peak. • Future residential building energy benchmark should be controlled at 0.703 (±0.042) Btce. • A benchmark of 1.258 BtCO 2 can achieve the residential buildings' 2030 emission peak goal. Fast-growing carbon emissions from the residential building sector are a hindrance for China to achieve its 2030 emission peak goal. To identify future low carbon roadmaps of residential buildings, this study is the first to assess the historical carbon mitigation and simulate the energy and emission peaks of China's residential building sector using a dynamic emission scenario. It shows that the emission mitigation of the residential building sector during 2000–2015 is 1.817 (±0.643) billion tons of carbon dioxide (BtCO 2), and the normal distribution-based scenario simulation demonstrates that the residential building sector will achieve its carbon emission peak in 2037 (±4) with a peak value of 1.419 (±0.081) BtCO 2. The sensitivity analysis reveals that the impacts of floor space per capita and energy intensity of urban residential buildings are the most significant for the uncertainty of emission peaks. A strict energy demand benchmark of the residential building sector suggests a control at 0.661 billion tons of standard coal equivalent (Btce), and its peaking time is estimated for 2035, which is 5 years ahead of the business-as-usual scenario, with energy savings of 0.042 Btce. For the earliest peaking time, if the residential building sector aims to achieve its emission peak before 2030, the emission peak should be controlled at 1.258 BtCO 2. Overall, this paper can assist the government in more accurate and feasible building emission mitigation strategies. Moreover, the results provide a more powerful decision-making reference in issuing targeted and feasible strategies for future residential building emission mitigation. [ABSTRACT FROM AUTHOR]

China's iron and steel industry is the key industry for the state to conserve energy and control CO 2 emissions. In this paper, we divide China's administrative regions into three groups using cluster analysis. Then we use energy and carbon dioxide performance index to evaluate the static efficiency in iron and steel industry. After, meta-frontier non-radial Malmquist directional distance function is constructed to measure the dynamic energy and carbon dioxide emission performance. The dynamic indicator is decomposed into efficiency change, best practice gap change, and technology gap change. According to this study, the static energy and carbon dioxide efficiency in China's iron and steel industry still lags behind from 2000 to 2016. Group 1 (mainly eastern provinces of China) has the highest efficiency, followed by group 2, and group 3 (mainly western provinces of China) has the lowest efficiency. The technical efficiency and technical progress are driving factors improving energy and carbon dioxide performance, while the technology gap change does not help to improve the performance. Finally, we propose specific policy recommendations to promote the healthy development of the industry. • We estimate energy and CO 2 efficiency of China's iron and steel industry. • Efficiency performance in iron and steel industry experiences positive changes. • EC and BPC are driving factors for efficiency performance improvement. • Technology gap change does not help to improve the energy and CO 2 performance. [ABSTRACT FROM AUTHOR]

The Paris Agreement on climate change has calls for urgent, radical, and transformative actions in mitigation and adaptation, particularly in terms of reducing greenhouse gas (GHG) emission. There are many terms used to describe the process of reducing GHGs, including decarbonization, low carbon development (LCD) or low carbon transition (LCT). The conceptualization of these terms remains puzzling and there has not been any consensus to explain the meaning and their interrelationship. Clearer definition and conceptual boundaries are necessary to improve the coherence of overarching practices to cut CO 2 emission. The paper aims to review key concepts related to climate change mitigation related to the reduction of CO 2 and efforts toward net-zero emission in the academic literature, by (1) examining progress of the literature over time, (2) identifying geographical locus and sectoral focus of the literature, (3) determining the interrelationships between the key concepts. We use a Systematic Literature Review (SLR) method for data collection by selecting peer-reviewed literature from Scopus and analyzing the data with content analysis and bibliometric analysis. The findings are, firstly, the publications of the literature are influenced by global and national climate change policies and the interest of scholars affiliated to institutions from major emitter countries. Therefore, the literature is mostly originating from countries that emit the most CO 2 while also implement mitigations to reduce CO 2 emission. Secondly, China is the country where studies are mostly focused and also where the authors are affiliated/located. However, publications from the United Kingdom are cited the most. Thirdly, there are three clusters of literature found, namely that LCD and LCT are the terms used to identify visions for climate mitigation, while decarbonization is the actions and processes to achieve either LCD or LCT (as the visions). • The dynamic of climate change policies influence the literature trend. • The literature is mostly originating from major CO 2 emitter. • Low carbon development and low carbon transition are visional terms. • Decarbonization indicates the processes of decoupling CO 2 to achieve the visions. [ABSTRACT FROM AUTHOR]