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Through extensive data research and analysis, this paper comprehensively summarizes the status and key insights of global carbon dioxide capture and storage (CCS) development. It aims to gain a comprehensive understanding of the relevant policies, technologies, and security measures adopted by major countries in their CCS development processes. Furthermore, it explores the existing status and limitations of China's offshore development efforts, while providing valuable recommendations for enhancing China's offshore CCS initiatives, as well as serving as a reference for other nations worldwide. Offshore CCS plays a crucial role for China to achieve the development target of carbon peak and carbon neutrality, due to its energy structure and industrial distribution. While China possesses significant offshore CCS potential, achieving commercialization still requires substantial efforts. To facilitate the process and draw insights from successful experiences in other countries, this paper illustrates the characteristics and generalizes the experience of offshore CCS industry practices in America, Europe and Japan, respectively. Furthermore, it is recommended that a new round of investigation into offshore CCS potential be conducted, while promoting integrated collaboration between geological surveying and marine scientific research. Additionally, further research on industrial policies and green financial strategies should be undertaken. [ABSTRACT FROM AUTHOR]

In 2017, a carbon emissions trading market will be launched nationwide by the China government. Calculating the enterprise carbon emissions is an important prerequisite and basis for trading. This paper discussed types of greenhouse gases, calculation boundaries and methods, energy consumption, carbon emissions, and intensity of a representative integrated pulp and paper mill in China based on China Guidance and Greenhouse Gas Protocol Tools. The results showed that there were 435,000 tonnes (t) of CO2 emissions from that mill in 2014 that did not contain emissions of biomass energy, which was 8 times higher than that of fossil energy. The pulp carbon intensity based on the mill was 0.230 t CO2/Adt, which accounted for 7.50% to 57.4% in other pulps' based on the product. Intensity based on Gross Domestic Product (GDP) was 1.090 t CO2e/1000 USD and accounted for 56.8% intensity in the China paper industry. The intensity based on sales accounted for 52.6% in the firstclass enterprise in the developed country. It also showed that intensity was influenced by the species of raw material, energy, and products, which provided the mill with measures for energy saving and emissions reduction to obtain the redundant carbon emissions in the trading. [ABSTRACT FROM AUTHOR]

Taking the Yangtze River Delta (YRD) of China as the research area, this paper studies the influence of freight structure adjustment and energy intensity on carbon dioxide (CO2) emission from the transportation industry. Sample data from 1990 to 2019 are selected, and co-integration analysis is performed using three independent variables: energy intensity, turnover ratio of railway to highway (R/H), and turnover ratio of railway to waterway (R/W). Then, an autoregressive distribution lag-error correction model (ARDL-ECM) is established to estimate the long-run and short-run relationships among the variables through unit root test, autoregressive distributed lag (ARDL) boundary test, and Granger test. The results show that in the long run, the growth of energy intensity leads to the long-term growth of CO2 emission in the transportation sector of the YRD, and R/W and R/H have a suppressive effect on CO2 emission. Granger causality indicates that there is a bidirectional causal relationship between energy intensity and CO2 emission. This work can be a reference for government departments to formulate policies related to carbon emissions in the transportation industry. [ABSTRACT FROM AUTHOR]

Altay Prefecture, a typical arid region in northwestern China, has experienced the climate transition from warming-drying to warming-wetting since 1980s and has attracted widespread attention. Nonetheless, it is still unclear how climate change has influenced the distribution of vegetation in this region. In this paper, a reaction–diffusion model of the climate–vegetation system is proposed to study the impact of climate change (precipitation, temperature and carbon dioxide concentration) on vegetation patterns in Altay Prefecture. Our results indicate that the tendency of vegetation growth in Altay Prefecture improved gradually from 1985 to 2010. Under the current climate conditions, the increase of precipitation results in the change of vegetation pattern structures, and eventually vegetation coverage tends to be uniform. Moreover, we found that there exists an optimal temperature where the spot vegetation pattern structure remains stable. Furthermore, the increase in carbon dioxide concentration induces vegetation pattern transition. Based on four climate change scenarios of the Coupled Model Intercomparison Project Phase 6 (CMIP6), we used the power law range (PLR) to predict the optimal scenario for the sustainable development of the vegetation ecosystem in Altay Prefecture. [ABSTRACT FROM AUTHOR]

Environmental information disclosure (EID) is an important measure to promote multiple subjects' collaborative management of pollution emissions. In this paper, we first measure the carbon dioxide (CO2) emissions of 282 cities in China from 2006 to 2020, and clarify the theoretical mechanisms and transmission channels of EID affecting CO2. Subsequently, the Time-varying difference-in-differences (DID) and the mediation effect model are used to assess the impact of EID on CO2 and its transmission mechanism, respectively. The study shows that although EID is a voluntary environmental regulation, the policy significantly reduces CO2, and this reduction effect has regional and low-carbon policy intensity heterogeneity. The study also shows that green technology innovation and energy intensity mediate the carbon reduction effect of EID. This study has important reference significance for reducing greenhouse gas emissions and improving the quality of economic development. [ABSTRACT FROM AUTHOR]

CO 2 sequestration is an effective technology for reducing greenhouse gas effect. To ensure the safety, assessment of well applicability should be conducted before CO 2 sequestration. However, current studies mainly focus on identifying which barrier has the highest risk of leakage rather than selecting a target well for injection in specific geological formation. To further investigate, this paper proposes well applicability assessment method combining reservoir and wellbore properties together for CO 2 sequestration. A novel assessment system combing Fuzzy comprehensive evaluation and Analytic hierarchy process has been established. Twenty-nine indexes subjected to seven categories (i.e., formation, well, cement sheath, cementing quality, casing, tubing, and wellhead properties) are taken into consideration. The weighting factors of these seven categories are 0.0673, 0.0552, 0.096, 0.1537, 0.2283, 0.2637 and 0.1369, respectively. Tubing and casing properties have the greatest influence on safety injection. Furthermore, the proposed system has been applied to S gas reservoir, China. Results show that Wells #P1 and #P2 are suitable for injection. Since more comprehensive indicators are considered comparing with previous studies, the results are more accuracy and objective. The findings of this paper could help efficiently and effectively evaluating well applicability for CO 2 sequestration and reducing the risk of CO 2 leakage. [ABSTRACT FROM AUTHOR]

The geological storage of CO2 is a critical technique for reducing emissions, which significantly contributes to the mitigation of the greenhouse effect. Currently, CO2 is often geologically stored in coal seams, hydrocarbon reservoirs, and saline aquifers in order to store CO2 and improve the oil and gas recovery simultaneously. Shale formations, as candidates for CO2 storage, are drawing more attention because of their rich volumes. CO2 storage through shale formations in the Sichuan Basin, China, has tremendous potential because of the readily available CO2 injection equipment, such as abandoned shale gas wells. Therefore, we review the potential of using these wells to store CO2 in this paper. Firstly, we review the status of the geological storage of CO2 and discuss the features and filed applications for the most studied storage techniques. Secondly, we investigate the formation properties, shale gas field development process, and characteristics of the abandoned wells in the Sichuan Basin. Additionally, after carefully studying the mechanism and theoretical storage capacity, we evaluate the potential of using these abandoned wells to store CO2. Lastly, recommendations are proposed based on the current technologies and government policies. We hope this paper may provide some insights into the development of geological CO2 storage using unconventional reservoirs. [ABSTRACT FROM AUTHOR]

Aviation emission accounting is the key to establishing market measures to control aviation pollutant emissions. Based on the fuel percentage method (FPM), this paper applies the improved BFFM2-FOA-FPM (Boeing Fuel Flow Method 2–First Order Approximation FPM) to calculate the emissions of six pollutants (CO 2 , CO, HC, NO x , SO 2 , and PM 2.5) between Chinese and foreign cities from 2014 to 2019, including CCD (climbing, cruising, and descending) emissions and LTO (landing and take-off) emissions. The error rate between the calculated results and the official data is about 2.75 %. The results show that the emissions of six pollutants changed before and after the proposal of the "Carbon Neutral Growth 2020" strategy (CNG2020 strategy). Although the total amount has increased, the average emission per tonne-kilometer of CO 2 , CO, HC, NO x , SO 2 , and PM 2.5 has decreased by 17.77 %, 17.26 %, 25.15 %, 14.32 %, 17.77 %, and 16.35 %, respectively. The results of this paper can provide a data basis and method reference for implementing the CNG2020 strategy and realizing global carbon emission reduction goals. The dataset is available from https://doi.org/10.6084/m9.figshare.20071751.v1 (Cui., 2022). [ABSTRACT FROM AUTHOR]

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]

By purchasing emission reduction equipment or reducing production scale, it is possible to effectively decrease CO 2. Therefore, understanding the marginal abatement cost (MAC) associated with these methods is crucial for making decisions. However, previous studies using the directional distance function (DDF) approach often mis-specified production functions and neglected data noise. They also assumed decision-making units (DMUs) to be on the production frontier and used proportional changes in inputs and outputs as abatement paths. This paper addresses these limitations by developing the convex quantile non-radial directional distance function (CQR-NDDF) method, which estimates the MAC of CO 2 and determines optimal abatement paths for DMUs without assuming a specific production function, employing linear programming techniques. Applying this method to 30 provinces in mainland China from 2011 to 2019, the study finds that China's CO 2 MAC increased from 182 to 247 yuan/ton. The lowest-cost abatement path varies by province and time. The club convergence and ordered probit model are employed to conclude that the second industry and urbanization increase the MAC of CO 2 , while factors such as foreign direct investment, openness level, and human capital decrease the MAC. Moreover, the CQR-NDDF method yields significantly lower MAC estimates than the NDDF method. In conclusion, this paper provides new insights into China's CO 2 MAC, emphasizing the importance of considering inefficiency and data noise in MAC estimation. We anticipate that utilizing CO 2 MAC as a benchmark for carbon trading market prices could lead to an increase in prices within China's carbon trading market. • A novel method for estimating CO 2 MAC has been developed. • Ignoring inefficiency will result in an overestimation of CO 2 MAC. • Three different emission reduction pathways are considered in the estimation. • The heterogeneity of the lowest cost abatement pathways has been identified. [ABSTRACT FROM AUTHOR]

Marginal abatement cost (MAC) plays an essential role in pricing pollutants and guiding environmental policies. Considering the heavy polluting nature of China's coal power industry, this paper aims at providing companies and policymakers with more comprehensive information on the cost of abatement by estimating the MACs of CO2 and SO2 for coal-fired power plants (CFPPs) in China. This study contributes to the literature by considering an interconnected two-stage production system to investigate. The estimation framework is advanced in combining the electricity production and pollution abatement process of CFPPs into a convex quantile regression (CQR) model. The results show that the averages of MAC for CO2 and SO2 are estimated to be 367.56 Yuan/ton and 662.30 Yuan/ton, respectively, indicating that the reduction of such emissions is still costly. The heterogeneous analysis then indicates that large CFPPs, central-government-owned power plants (CGOPPs), and low-regulated CFPPs tend to possess lower MACs for CO2. Regarding SO2, large and medium-sized power plants show significantly larger MACs than small plants. In addition, the MACs of SO2 for CGOPPs and high-regulated CFPPs are more concentrated at high levels. In the second part, the Tobit regression analysis was used to discuss the determinants of MACs for CO2 and SO2. Factors like carbon emission intensity, load, and operating hours can notably decrease MACs for CO2, while MACs for SO2 tend to be positively affected by the total abatement cost and the abatement rate of the FGD equipment. In addition, the MACs for the large CFPPs, CGOPPs, and high-regulated CFPPs are more likely to be affected by the selected influence factors. Based on these results, we conclude with some policy recommendations. [ABSTRACT FROM AUTHOR]

It is proposed to develop a novel thermochemical cycle using nuclear energy to decompose H 2 S and CO 2 , thus producing H 2 and CO from acidic gas in petrochemical or coal chemical industries, reducing CO 2 emissions and promoting sustainable energy development. The upper limits and significant energy-consuming steps were determined based on two chemical routes of the thermochemical cycle systems 1 and 2. When the enthalpy of the H 2 S oxidation reaction served as part of the circulating energy input, the values for system 1 and system 2 were 38.7% and 34.3%, respectively. However, if only external energy is considered to satisfy the heat and work required to run the reaction and pump, the thermal efficiency rises to 58.4% and 61.2%, respectively. The life cycle assessment (LCA) was used to investigate the environmental effect of the hydrogen generation process base on the upper thermal efficiency in this study, and the results of the LCA are stated in terms of global warming potential (GWP) and acidification potential (AP). The GWP of systems 1 and 2 was calculated as 2.59 kg CO 2 -eq/kg H 2 , 2.54 kg CO 2 -eq/kg H 2 , The AP of systems 1 and 2 was calculated as 7.48 g SO 2 -eq/kg H 2 and 9.08 g SO 2 -eq/kg H 2 , respectively. This paper assesses the environmental effect of two different hydrogen systems used in manufacturing various subsystems in GWP and AP, and compares them to the life cycle of other hydrogen production pathways. • A novel thermochemical cycle using nuclear energy to split H 2 S-CO 2 is proposed. • Energy-consuming steps and the upper thermal efficiency were determined. • The upper thermal efficiency has been developed to assess environmental impacts. • The LCA integrated China's HTR-PM with the innovative H 2 S-CO 2 process. • GWP and AP in the H 2 S-CO 2 system are compared to other hydrogen methods. [ABSTRACT FROM AUTHOR]

Methane (CH4) is the second-largest greenhouse gas emitted by human activity and natural sources after carbon dioxide (CO2). Its relatively short lifetime in the atmosphere (about 12 years) means that we can mitigate the human impacts of climate change in a relatively short period of time by reducing CH4 emissions. The creation of CH4 emissions management policies can be based on the distribution maps of surface CH4 concentration that are in large-scale and at high-resolution. The estimate of CH4 emissions with broad coverage are provided by currently extensively used satellite data supplemented with data from model simulations. However, it is at low spatial resolution. In this paper, through the combination of atmospheric CH4 observations from the TROPOMI sensor and wind data from the ECMWF global reanalysis, a straightforward divergence method is proposed to estimate the surface CH4 emissions in China from March 2019 to September 2022 at a resolution of 7 km × 7 km. This method was compared with the average annual CH4 emissions of Emissions Database for Global Atmospheric Research (EDGARv7.0), and the Root Mean Square Error (RMSE) is 2.53 kg/km2/h and within error envelop (EE) is 72.93%, which represents the proportion of reliable values under certain uncertain conditions. We estimated that the average annual CH4 emissions in China from 2019 to 2022 is 81 Tg, with the lowest emissions in 2021 (75 Tg) due to the impact of COVID-19. In 2021, the largest anthropogenic emissions in China are from agriculture, energy activities and livestock, accounting for 28% (20.8 Tg), 25% (18.9 Tg) and 19% (13.9 Tg) of total emissions, respectively, while wetlands, as the largest natural source, produce 14% (10.5 Tg) of CH4 emissions. [ABSTRACT FROM AUTHOR]

There are large, heavy oil reserves in Block X of the Xinjiang oilfields, China. Due to its large burial depth (1300 m) and low permeability (26.0 mD), the traditional steam-injection technology cannot be used to obtain effective development benefits. This paper conducts experimental and simulation research on the feasibility and mechanism of CO 2 -energized fracturing of horizontal wells and N 2 foam huff-n-puff in deep heavy oil reservoirs with low permeability in order to further explore the appropriate production technology. The foaming volume of the foaming agent at different concentrations and the oil displacement effect of N 2 foam at different gas/liquid ratios were compared by the experiments. The results show that a high concentration of foaming agent mixed with crude oil is more conducive to increasing the foaming volume and extending the half-life, and the best foaming agent concentration is 3.0∼4.0%. The 2D micro-scale visualization experiment results show that N 2 foam has a good selective blocking effect, which increases the sweep area. The number of bubbles per unit area increases as the gas/liquid ratio increases, with 3.0∼5.0 being the optimal gas/liquid ratio. Numerical simulation results show that, when CO 2 -energized fracturing technology takes into account the advantages of fracturing and crude oil viscosity reduction by CO 2 dissolution, the phased oil recovery factor in the primary production period can reach approximately 13.7%. A solvent pre-slug with N 2 foam huff-n-puff technology is applied to improve oil recovery factor following primary production for 5∼6 years, and the final oil recovery factor can reach approximately 35.0%. The methodology formulated in this study is particularly significant for the effective development of this oil reservoir with deeply buried depth and low permeability, and would also guide the recovery of similar oil deposits. [ABSTRACT FROM AUTHOR]

Electrocatalytic CO2 reduction is regarded as a green and promising technology because it can convert carbon dioxide into value-added fuel or chemicals in a flexible and sustainable way. This research aimed to comprehensively analyze the research hotspots and trends in the field of CO2 electroreduction from 2005 to 2022 using bibliometric methods based on the core database of Web of Science. The results showed that 4546 papers on CO2 electroreduction were retrieved from 2005 to 2022, with a clear increasing trend. The research direction was diversified, involving multiple disciplines, and it is a comprehensive research field. ACS Catalysis is the journal with the largest number of articles. China is the country with the largest number of documents and has made significant contributions to the development and progress of this field. Copper-based catalysts are still the research focus in recent years. It is of great practical significance to develop copper-based catalysts with high efficiency, low cost, high stability, and high selectivity for the preparation of C1 products. [ABSTRACT FROM AUTHOR]

Following China and the United States, India is the third highest CO2 emitter in the world. With its fast rising population and an industry primarily reliant on coal and oil, the country's emissions will continue to rise unless appropriate measures are taken. In India generally the carbon sequestration is done by storing CO2 in sedimentary basins where it gets capped by the impermeable cap rocks. The study aims to unfold the other techniques of carbon sequestration in subsurface formations, except for narrating the different types of carbon capture and sequestration techniques along with its storage in different types of environments. For instance, abiotic and biotic environments for CO2 sequestration. It further talks about carbon injections of oceanic, geological, and terrestrial types, to name just a few. Types of carbon emission sources are discussed too. In this paper three different approaches are described for carbon mitigation, namely CarbFix, CO2 Plume technology and Carbon Trading. A prefeasibility study was done in order to implement the three techniques in Dholera geothermal region in Gujarat, India. In literature review, it can be seen how the three techniques can help in permanent mitigation of captured carbon through carbonate mineralization, power generation and industrial applications. For any project government and public participation is important. In this regard the study gives a brief understanding about the steps to be taken by government and the public to promote such projects for carbon mitigation. Besides, the steps to be taken in such projects for health and risk assessment were talked about in literature review too. [ABSTRACT FROM AUTHOR]

With the proposal of China's national "double carbon" strategic goal, carbon capture, utilization and storage (CCUS) technology has attracted more and more attention. Due to the high cost, high energy consumption and high risk of CCUS technology, this technology is still in the initial stage of development in China. Among them, CO2 geological storage is one of the risks, and the environmental monitoring technology of CO2 storage leakage is particularly important in the large-scale popularization and application of CCUS technology in China. On the basis of extensive research on the related literature concerning CO2 storage and leakage, this paper begins with the types and mechanisms of CO2 storage, analyzes the ways and risks of CO2 storage and leakage and then summarizes the existing environmental monitoring technologies of CO2 geological storage and leakage. In the future, China can promote the progress of CO2 geological storage monitoring technology and help achieve the goal of "double carbon" by strengthening the research on CO2 storage mechanism and main control factors, perfecting the risk assessment method of CO2 storage, constructing the monitoring technology system of the CO2 storage life cycle, and standardizing the CO2 storage risk response system. [ABSTRACT FROM AUTHOR]

China's economy has made significant strides in the past three decades. As a direct result of China's "one belt, one road" (OBOR) initiative, the country's rate of industrialization and urbanization is currently the fastest in the entire world. This rapid development is largely dependent on the enormous amounts of energy currently being consumed and forms the foundation of the world's high levels of carbon emissions. It is generally agreed that the production of greenhouse gases, particularly carbon dioxide, is the primary contributor to the current state of climate change. In this paper, a CO2 emission prediction model based on Bi-LSTM is constructed. In order to conduct empirical tests on the model, this study uses data from South Asian countries and China from 2001 to 2020. China's CO2 emissions from 2022 to 2030 were predicted along with those of other countries in order to study the combined effects of the scientific and technological progress, industrial structures, and energy structure factors affecting CO2 emissions. When compared with the LSTM and GRU methods, the Bi-LSTM model's results produced lower MAE, MSE, and MAPE values, indicating that it performs better. According to the findings, carbon emissions represent a significant problem that will become much worse in the future due to China and India's high emissions, particularly in the next 10 years, if the government does not implement policies that help reduce those emissions. [ABSTRACT FROM AUTHOR]

As the largest carbon dioxide emitter, China is working towards the direction of a green economy. As an irreplaceable part of establishing a green economy, the low-carbon city pilot (LCCP) policy is implemented in many large cities in China, and the scope of implementation will be further expanded. However, to date, there has been an absence of empirical studies basing on prefecture-level cities about the evaluation of China's LCCP policy. Evaluating and optimizing the LCCP policy is constructive to achieve the goal of China's green economic transition. In this paper, we evaluated the effect of the LCCP policy on China's low-carbon economic transition by using the difference-in-difference (DID) approach which can effectively alleviate endogenous problems and better evaluate this effect and the panel data of 210 prefecture-level cities in China from 2008 to 2016. The empirical analysis revealed that the LCCP policy inhibited China's low-carbon economic transition in general. Specifically, the policy worked well in the eastern region but failed in the central region and western region by studying the regional heterogeneity and influence mechanism. The reason is that the LCCP policy can stimulate low-carbon innovation with the help of innovation offset effects in the eastern region, but it failed to do so in the central region and western region. In addition, this paper analyzed the performance of three types of policy tools adopted by local governments to implement the policy, we found that market-economic tools are valuable to improving the low-carbon economic transition in pilot areas, but command-mandatory tools and voluntary tools have failed to achieve the expected objectives. The research results of this article can provide policy recommendations for optimizing the low-carbon policy and provide a reference for countries that are determined to develop a green economy. [ABSTRACT FROM AUTHOR]

Countries worldwide consider solid waste collection and recycling necessary due to the recent emphasis on conservation of resources and environmental protection. Due to the constraints from resource depletion and the need for sustainable economic growth, solid waste recycling has become a critical issue in China. Several indigenous researchers in China have studied the potential benefits of solid waste recycling. However, most studies limited the environmental assessment of solid waste recycling to greenhouse gas (GHG) emissions and considered only one type of solid waste (paper or plastic). Therefore, the present study analyzed the energy (electricity) and environmental (GHG and air pollutant emissions) benefits of recycling steel, nonferrous metal, plastic, and paper wastes from 2005 to 2017 in China. The study used the formulation of model equations method to estimate the electrical energy and environmental benefits. Prominent findings show that the total amount of electricity saved by recycling solid waste from 2005 to 2017 was 3743.3 Mtce. On average, solid waste recycling during the period led to a 43.2% saving on electricity. Solid waste recycling avoided 4765.9 billion kg of carbon dioxide emission and 22.502 billion kg of methane emission. It was also found that the recycling of solid waste saved a total amount of 10,669.8 M kg of NO X emission but had a burden of −6263.2 M kg of VOCs emission on the environment. Solid waste recycling avoided the emission of CO 2 , CH 4 , NO X , and SO X, but the recycling of steel, plastics, and paper waste had negative impacts on the environment in terms of VOCs and PM emissions. Proper measures such as installing air pollution control devices should be put in place to minimize the emission of pollutants during the recycling of these solid wastes. • The energy and environmental benefits of solid waste recycling is assessed. • The formulation of model equations method was used for the assessment. • On average, the recycling of solid waste saved 43.2% of electricity. • Recycling of waste avoided a significant amount of GHG and air pollutant emissions. • Solid waste recycling had no essential benefit on the emission of VOCs and PM. [ABSTRACT FROM AUTHOR]

Most conventional air pollutants and carbon dioxide (CO2) are simultaneously emitted from the same sources, providing a sound theoretical basis for the synergistic governance of these emissions. At present, China faces severe challenges in protecting the eco-environment, such as reducing conventional pollutants, improving environmental quality, and peaking CO2 emissions. Internationally, the control of greenhouse gas (GHG) emissions has been incorporated into the comprehensive environmental management system in major developed economies such as the United States (US) and the European Union (EU), where, based on GHG emissions monitoring and statistical data, decision-making support is provided for the national governments in the form of policy evaluation, thus forming a management mode that enables overall planning, coordination, and unified regulatory at the national level and participation of multiple departments under the national government. The synergistic control of conventional air pollutants and GHGs is becoming an important measure to strengthen the environmental management and achieve low-carbon development. This paper summarizes the synergistic effects of reducing air pollution and carbon emissions from the aspects of synergistic policies, strategic planning, and institutional systems, and conducts an analysis based on existing synergistic practices. [ABSTRACT FROM AUTHOR]

The conventional air conditioning system used in high-speed railways has limitations in heating performance and environmental impact, necessitating the exploration of alternative refrigerants. The transcritical CO 2 system has gained popularity due to its exceptional heating efficiency and environmental benefits. This study aims to evaluate the energy and environmental potentials for transcritical CO 2 systems in high-speed trains based on four-vertical-and-four-horizontal railway lines within different climatic regions of China. A high-fidelity transcritical CO 2 system model was first developed and validated through experiments. Then, a comprehensive energy and environmental evaluation method was proposed and applied to the four-vertical-and-four-horizontal railway lines. The results indicated that the transcritical CO 2 system had a superior heating performance and competitive cooling performance based on daily and annual operations. Furthermore, the transcritical CO 2 system exhibited significant environmental advantages with lower total life cycle climate performance for all lines, with an average emissions reduction ratio of 17.6% and a maximum emissions reduction ratio of 26.98%. These findings highlight the competitive energy performance and outstanding environmental benefits offered by transcritical CO 2 systems as promising alternatives to air conditioning systems in railway transportation. • This paper evaluates the potential of theCO 2 system in high-speed trains from an energy performance and environmental benefits perspective. • A high-fidelity model of the transcritical CO 2 system is developed and validated for effectiveness through experiments. • The energy and environmental evaluations are conducted based on China's four-vertical-and- four-horizontal railway lines. • The results indicate that the CO 2 system presents a competitive alternative for air conditioning systems in high-speed trains. [ABSTRACT FROM AUTHOR]

Exploring whether informal environmental regulations (INER) can achieve carbon reduction in the context of pollution reduction and carbon reduction, as well as how to achieve carbon reduction, can help solve the dual failures of the market and government in environmental protection. Based on the polycentric governance theory and considering the characteristics of social subject environmental participation, the Stackelberg game is used to demonstrate the impact mechanism of INER on CO 2. In addition, using the panel data of China's 30 provinces from 2003 to 2018, this paper validates the effectiveness of INER by Pooled Ordinary Least Square (POLS) and threshold panel model. Then, the mediating effect model is used to test the mechanism of INER's effect on carbon reduction. The results show that corruption is not conducive to CO 2 reduction. The reduction effect of INER on CO 2 exhibits heterogeneity with changes in other non-greenhouse gas pollutants. While INER effectively reduces local corruption, its more substantial indirect impact on CO 2 reduction is prominent when levels of other pollutants are lower. Comparative analysis reveals that there are still biased governance behaviors to cope with INER's pressure in some regions nowadays. The findings show that for countries facing the dual task of pollution control and carbon reduction, the key to leveraging the supervisory role of INER should be focused on mitigating information asymmetry caused by the characteristics of CO 2. Therefore, in the process of environmental protection, the public environmental participation system should be improved, and the process of disclosing polluters' carbon information should be accelerated. • Polluters may adopt strategic carbon reduction behaviors. • Other pollutants influence the impact of INER on CO 2. • When other pollutants are low, INER significantly reduce CO 2 by constraining corruption. • Some regions still have biased governance behaviors to cope with INER's pressure. [ABSTRACT FROM AUTHOR]

Since China's reform and opening up, the social economy has achieved rapid development, followed by a sharp increase in carbon dioxide (CO2) emissions. Therefore, at the 75th United Nations General Assembly, China proposed to achieve carbon peaking by 2030 and carbon neutrality by 2060. The research work on advance forecasting of CO2 emissions is essential to achieve the above-mentioned carbon peaking and carbon neutrality goals in China. In order to achieve accurate prediction of CO2 emissions, this study establishes a hybrid intelligent algorithm model suitable for CO2 emissions prediction based on China's CO2 emissions and related socioeconomic indicator data from 1971 to 2017. The hyperparameters of Least Squares Support Vector Regression (LSSVR) are optimized by the Adaptive Artificial Bee Colony (AABC) algorithm to build a high-performance hybrid intelligence model. The research results show that the hybrid intelligent algorithm model designed in this paper has stronger robustness and accuracy with relative error almost within ±5% in the advance prediction of CO2 emissions. The modeling scheme proposed in this study can not only provide strong support for the Chinese government and industry departments to formulate policies related to the carbon peaking and carbon neutrality goals, but also can be extended to the research of other socioeconomic-related issues. [ABSTRACT FROM AUTHOR]

Livestock is one of major sources of greenhouse gas (GHG) emissions in China. Clarifying spatiotemporal characteristics of GHG emissions from livestock and exploring influencing factors can provide reference for grasping regional changes of GHG emission and formulate strategies of carbon reduction for livestock industry. However, existing literatures considered both spatial and temporal impacts and dynamic evolution trend of these factors seldomly. This paper used the life cycle assessment (LCA) method to estimate GHG emissions of livestock in 114 cities of the YRB from 2000 to 2021. On this basis, spatiotemporal heterogeneity of influencing factors was analyzed by using geographically and temporally weighted regression (GTWR) model. Finally, future evolution trend of GHG emissions from livestock was predicted by combining traditional and spatial Markov chain. Four main results were listed as follows. Firstly, GHG emission in the life cycle of livestock industry increased from 57.202 million tons (Mt) carbon dioxide equivalent (CO 2 e) in 2000 to 77.568 Mt CO 2 e in 2021. Secondly, structure of livestock industry, labor flow and mechanization were vital factors that led to increase of GHG emissions from livestock. Positive effects of labor flow and mechanization were increasing year by year, while negative effect of urbanization and positive effect of economic development were decreasing year by year. Markov chain analysis shown that probability of keeping high level of GHG emissions of livestock in the YRB unchanged were 96% (T = 1) and 90% (T = 5), and there also existed a Matthew effect. In addition, probability of level transfer of GHG emission in urban livestock was spatially dependent. Government should formulate strategies for livestock development and optimize low-carbon transformation of energy structure for livestock and poultry husbandry based on local conditions and key driving factors in the future. Meanwhile, boundaries of administrative divisions should be broken to promote reduction of GHG emissions in livestock comprehensively. • GHG emissions from livestock in cities of the YRB continued to rise from 2000 to 2021. • GHG emissions per unit of GDP of livestock shown a downward trend. • Analyzing parameter of factors from spatiotemporal aspect by using GTWR model. • Probability of GHG emission transfer in urban livestock was spatially dependent. [ABSTRACT FROM AUTHOR]

Both environmental regulation (ER) and different pollutants emission are characterized by differentiation, but the nonlinear relationship between different intensities of ER and different levels of pollutants emission has not yet been elaborated. This paper examines the nonlinear effects of ER at different intensities on PM 2.5 and CO 2 at different states with the help of cutting-edge Quantile on Quantile Approach (QQA), comprehensively reveals the inner law of ER to promote pollutants synergistic reduction. This study found that, both PM 2.5 and CO 2 show obvious regional differences but are not polarized. ER can effectively help reduce PM 2.5 and CO 2 in average, and this reduction effect is more obvious for central-western cities. The effects of different intensities of ER on different states of PM 2.5 and CO 2 have obvious nonlinear spillover characteristics. The impact of ER on PM 2.5 shows wave-like changes. Increasing ER intensity has a stronger inhibitory effect on PM 2.5 of high scale, but when PM 2.5 is relatively low, moderate ER is needed to match it, and excessive intensity of ER will be detrimental to reduce PM 2.5. The negative impact of ER on CO 2 fluctuates relatively stable. ER at high quantiles have more obvious reduction effect on CO 2 of high levels, but excessive intensity of ER is not conducive to reduce CO 2. Achieve the synergistic reduction of PM 2.5 and CO 2 should not only consider the differences in ER between regions, but also to combine the scale differences of pollution and carbon emission. Our study suggests that the improvement of synergistic emission reduction system needs to consider the strength of ER and the level of pollutants emission according to local conditions, which will help to realize green development more efficiently. • Assessing the impacts of different intensities of ER on different levels of PM 2.5 and CO 2. • The use of QQ approach can obtain richer nonlinear information. • The effects of ER on PM 2.5 and CO 2 are asymmetric and heterogeneous. • Increasing ER intensity has a stronger inhibitory effect on PM 2.5 of high scale. • Nonlinear changes in the negative impact of ER on CO2 fluctuates relatively stable. [ABSTRACT FROM AUTHOR]

Carbon Capture, Utilization, and Storage (CCUS) is an indispensable technology to achieve carbon neutrality in China, but confined by technology and economy, the offshore CCUS in China is still in the planning stage and has not yet reached the desired scale. Offshore source-sink matching and cost analysis of CCUS is the premise and basis of offshore CCUS deployment. Thus, based on the CO 2 storage potential of offshore sedimentary basins in China, this paper conducts the offshore source-sink matching and cost analysis of CCUS in China under different constraints. The result showed that: ⅰ) the CO 2 storage capacity of China's offshore sedimentary basins is estimated to be 767.3 Gt, which is enough to meet approximately 200 years of coal power CO 2 emissions in China. ⅱ) the CO 2 storage potential could reach 721.9 Mt/a by source-sink matching under different constraints. ⅲ) early opportunities for offshore CCUS would be in the Bohai Bay and Pearl River Mouth Basin, considering the compensation effect of CO 2 -EOR. ⅳ) combined with the CCUS cost and emission reduction in China under different time nodes, it is inferred that deploying offshore CCUS in China between 2030 and 2040 commercially will be advantageous. • The CO 2 storage potential in China's offshore sedimentary basin was evaluated. • The cost of offshore CCUS was analyzed under different technology combinations. • Bohai Bay and Pearl River Mouth Basin would be early opportunities for offshore CCUS. • 2030–2040 would be the favorable time to deploy the large-scale offshore CCUS. [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]

In recent years, China's air quality problem is very serious. Among them, carbon dioxide emissions have been high, which has caused a series of ecological and environmental problems. In order to deeply study the relevant problems, this paper selects the information priority damping gray model to study and predict the carbon emissions of thirty-one provinces and municipalities in China. The model can give priority to new information and adjust the prediction trend, the accuracy of the model is verified by several cases. Through the data collection and data analysis of relevant provinces and cities, it is concluded that a total of twenty-one provinces and municipalities can reach the carbon peak in 2030, of which the carbon dioxide emission of Beijing is expected to drop to 51.3774 million tons by 2030. Ten provinces will not be able to reach the carbon peak by 2030. Among them, by 2030 the carbon dioxide emission of Jiangsu Province is expected to increase to 84.4668 million tons, but the growth rate is declining. The research results can be used as a reference for relevant departments. [ABSTRACT FROM AUTHOR]

This paper analyzes the time-varying impacts of Chinaʼs economic growth, energy efficiency, and industrial development on carbon dioxide (CO2) emissions from 1970 to 2019. First, we examined and found that there are two significant structural changes in the CO2 sequence over the years, and there was a significant nonlinear relationship among the four. The first nonlinear structural model constructed is the TVP regression model. According to the Bayesian model comparison criterion, TVP-SV-VAR was selected as the second constructed model from four types of VAR models containing nonlinear structures. The results show that the conduction intensity value of energy use efficiency to CO2 emissions has increased year by year, from 0.45 in 1971 to 0.97 in 2019. The short-term transmission mechanism of energy use efficiency to carbon emissions is the most significant. The conduction intensity of Chinaʼs economic growth on CO2 emissions increases year by year. Chinaʼs economic growth plays a major role in long-term CO2 emission reduction. The impact of industrial development on CO2 emissions reached a peak of 0.34 in 1977, and the intensity of the impact has basically stabilized at 0.26. [ABSTRACT FROM AUTHOR]

Negative emission technologies driven by nature with less energy input, lower costs, and long carbon storage capacities are essential for meeting ambitious global carbon mitigation goals. This paper evaluates the carbon sequestration potential of bivalve shellfish farming because its sequestration process is driven by nature, and it is cost-effective and energy efficient. The carbon in shells and the carbon that enters sediments via bio-deposition are long-lived forms of carbon. Using China as a case study, a preliminary estimation suggests that the carbon sequestration efficiency and intensity of cultivated shellfishes are much higher than those of artificial forests. In China, approximately 6.23 Mt CO 2 -eq a−1 was fixed via net carbon sequestration during shellfish growth from 2015 to 2019. In addition, the farmed shellfishes provided 0.37 Mt of harvested protein, and approximately 37.39 Mt CO2-eq a-1 were reduced compared to the same amount of protein provided by beef, and thus, shellfish farming has the win-win benefits of carbon sequestration and high-quality food provision. More importantly, a total of 5.64 Gt CO 2 -eq, accounting for 17.63% of the total emissions in 2020, can be potentially sequestrated at the global scale under the world's largest farming area scenario. • A Negative Emission Technology via shellfish farming was introduced. • Carbon sequestration function and efficiency of shellfish farming were investigated. • Carbon sequestration potential for bivalve shellfish farming was evaluated globally. • Life cycle GHG emissions of shellfish farming in China was assessed. [ABSTRACT FROM AUTHOR]

This paper examines the long-term effects and related short-term movements of energy security (ENS), economic policy uncertainty (EPU), and government ecological expenditure (GEE) on China's carbon dioxide (CO 2) emissions by applying the quantile autoregressive distributed lag approach. The empirical findings demonstrate that ENS and EPU have prominent negative and positive impacts, respectively, on CO 2 emissions in the long term for the majority of quantiles, while their short-term influences are less obvious. In addition, the effect of GEE is short-term and concentrated in high quantiles. The following are the article's main contributions. This study builds special energy security indicators based on the actual situation in China, providing a basis for better understanding the interaction mechanism between ENS and CO 2. Considering that China is the largest oil importer and greenhouse gas emitter, this study explores for the first time the linkages between ENS and CO 2. Both short- and long-term impacts are observed, and long-run effects are dominant in the linkages among variables, suggesting that the level of CO 2 emissions is mainly driven by long-term shocks. In addition, to clarify the nexus between ENS and CO 2 , time- and quantile-varying analyses are used, which take into account not only varied CO 2 emission levels but also distinct time periods for events. The findings emphasize the importance of market participants to form a better understanding of how ENS, EPU, and GEE affect CO 2 under different emission levels. Some detailed policies, including optimizing the energy consumption structure, making prudent economic policy adjustments, and strengthening ecological protection expenditures, are provided to curb pollution. • Energy security and carbon neutralization are main targets for China. • Energy security negatively affects carbon dioxide in the long-term. • Time-varying and quantile-varying features are captured for Energy security. • The quantile autoregressive distributed lag model is utilized in this paper. [ABSTRACT FROM AUTHOR]

• This paper conducts the assessment of CO2 storage capacity of offshore saline aquifers including Bohai Bay Basin in northern China, also Beibu Gulf Basin and Yinggehai Basin in southern China. • Different assessment methodologies are applied, and the mechanism and results are compared to analyze the applicability. • Results show that the CSLF and CO2BLOCK methods take into the account the storage mechanisms such as geological structure storage, residual gas storage and dissolution storage, the results seem more reasonable. Also different storage time interval could results in various capacity potential under safe injection in CO2BLOCK method. • In summary, the CO2 storage potential of Bohai Bay Basin, Beibu Gulf Basin, and Yinggehai Basin are 39.98, 53.22, and 13.37 Gt, respectively. Saline Aquifer CO 2 Storage (SACS) has become a vitally important technology for mitigating climate change brought on by anthropogenic and fossil fuel emissions. Application of SACS projects in offshore saline aquifers in China is quite promising, and the CO 2 storage technical and economic potential are considerable. However, the storage capacities achieved from different analytical and numerical methods varies a lot from each other since the main factors taken into account are variable. In this paper, different methodologies are applied to conduct the assessment of CO 2 storage capacity of offshore saline aquifers including Bohai Bay Basin in northern China, also Beibu Gulf Basin and Yinggehai Basin in southern China. Results show that the storage capacity obtained from European Commission's method is much less than that determined by the other three methods (i.e., USDOE, CSLF and CO2BLOCK method) since it mainly effected by the area of the saline aquifers. Since both of the CSLF and CO2BLOCK methods take into the account the storage mechanisms such as geological structure storage, residual gas storage and dissolution storage, the results seem more reasonable. In addition, the CO2BLOCK method considers the formation stability during injection as well, which is more in accordance with the reality. In summary, the CO 2 storage potential of Bohai Bay Basin, Beibu Gulf Basin, and Yinggehai Basin are 39.98, 53.22, and 13.37 Gt, respectively. This further verifies the great potential of industrial-scale pilot and demonstration CO 2 storage projects in offshore deep saline aquifers in China. [ABSTRACT FROM AUTHOR]

The credible sources of fossil energy efficiently are a vital cause of economic growth and considerable influence on adequate security. Whereas radiant energy positively enhances or ostensibly promotes socio-economic stability and the controlled environment. The fossil energy sources supply has become progressively stern in China and reconnoitering the beta decoupling relationships between CO2 emissions, GDP, energy consumption, electricity consumption, value-added industries, and population. The results will be favorable for illustrative the security of the valuable resources. This study adopts the extended stochastic model (STIRPAT) with Beta Decoupling Techniques (BDT). This modern technique merely employs the decoupling situation by the alpha and beta effects from 1989 to 2018 and calculates the % change in CO2 emissions by GDP growth and energy consumption. The estimated results represent negative and economic growth depends on coal and natural gas. First, CO2 emissions annually increasing cause of rapid growth, energy consumption, and electricity production, and the structural contradiction of energy remained static. Second, the Value-added industries estimated that CO2 emissions reduce by primary industries. Third, the decoupling states of CO2 emissions and population show an inverse relationship. This paper tentatively suggests China is sustainable, naturally strengthens energy output, transmutes the energy consumption structure, and advances development policies under environmental circumstances. [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]

• Solar-assisted PCM- based co-electrolysis of H 2 O and CO 2 for methanol production. • Energy, exergy and economic analysis of proposed high temperature innovative system. • Solar-to-fuel efficiency, methanol production and levelised fuel cost have competitive index. The co-electrolysis of H 2 O and CO 2 in a solid oxide electrolyzer cell (SOEC) integrated with solar energy leads to the development of renewable or near-zero emission technology for methanol production. Renewable methanol synthesis utilizing H 2 O and CO 2 captured from different industrial processes has received much attention. In this paper, a high-temperature electrolyzer integrated with solar dish collectors and photovoltaic arrays is proposed and investigated for syngas production and methanol synthesis. Phase change material is used for long-duration thermal energy storage to make an uninterrupted operation. Thermo-economic and technical feasibility analysis of the proposed system is performed and the most influential operating parameters (direct normal irradiance, current density, SOEC operating temperature and pressure) are varied to evaluate the system's performance by parametric study. The hourly data for the year 2021 of the direct normal irradiance (W/m2), wind speed (m/s) and ambient temperature (°C) for the studied location in China is accessed and presented. The results of the study show that solar-to-fuel efficiency and methanol production rate are 29.27 %, and 41.85 kg/h, respectively, while the levelised cost of fuel (LCoF) is calculated at approximately 0.399 Euros/kg. The sensitivity analysis for the economic and thermodynamic structure is conducted and discussed. [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]

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]

RP-3 kerosene fuel is the dominant hydrocarbon fuel used in civilian airplanes in China. Lately, many administration and universal organizations imposed a stringent standard for civilian airplanes pollutants emission. The amount of pollutants emission can be affected by the introduction of a variety of additives into flames, such as inert diluents, gaseous additives. This paper reports the effects of different inert gases (nitrogen and helium) and carbon dioxide dilutions in the oxidizer side on soot characteristics generated from RP-3 kerosene inverse diffusion flames. Flame diluted by carbon dioxide produced less amount of soot compared to flames diluted by nitrogen and helium, possibly because of changes in flame shape and properties such as flame diameter and availability of oxygen atoms. Carbon dioxide suppressed soot precursors formation in inception zone and released particles with smaller diameter due to lack of hydrogen radicals, an increase of hydroxyl radicals pool concentration, and decrease in flame temperature. Flame diluted by helium generated much soot aggregates with bigger primary particles diameter compared to base flame (flame diluted by nitrogen) as a result of high temperature. Soot particles produced in carbon dioxide diluted flame had more amorphous nanostructure, longer interlayer spacing and nanocrystallite height, shorter nanocrystallite width, lesser number of layers, and higher oxygen content compared to flame diluted by nitrogen and helium, which reflected a better oxidation reactivity among other diluted flames. [ABSTRACT FROM AUTHOR]

• The entrance of new countries into EU increased the trade among these countries and the EU's old members. This scenario of changes in trade patterns influenced the distribution of environmental pressures among countries, in particular, CO 2 emissions. • The changes in economic structure in the New European Union countries, given their insertion in a globally integrated supply chain, are important to explain the evolution in their CO 2 emissions. • Sourcing pattern changes contributed to the increase of CO 2 emissions in the New European Union countries. • The emissions' reductions associated with technology advances were not large to fully compensate for increases due to the change in sourcing patterns in the New European Union countries. This paper's interest lies in the environmental pressures of the European Union (EU). EU membership requires a series of economic and political changes that should impact a country's production and consumption structures and its trade relationships. These changes, in turn, will affect CO 2 emissions sources and levels. This is especially true for the new Member States that joined during the 2004–2007 enlargement of the European Union, given the difference in their levels of development and production structure. As these countries increase participation in a globally integrated production chain their emission's structure and level should change. Using a Structural Decomposition Analysis we are able to quantify the main drivers of changes in emissions differentiating six components, namely: emissions intensity, industrial structure and sourcing, consumer preferences, final demand sourcing and consumption levels. Grouping the countries into five groups, New European Union countries, Old European Union countries, the United States of America, China, and the Rest of the World, we measure trading pattern changes and their impact on CO 2 emission levels. The main results show that, although New European Union countries countries' emissions generally declined, the changes were not large enough to offset their increased emissions from access to more and wider ranging export demand. Increased CO 2 emissions embodied in final goods exports were especially notable. [ABSTRACT FROM AUTHOR]

Under the situation of global low-carbon development, the contradiction among energy consumption, economic growth, and CO2 emissions is increasingly prominent. Considering the possible two-way feedback among the three, based on the panel data of 30 regions in China from 2000 to 2017, this paper establishes a spatial Durbin model including economic growth, energy consumption equation, and CO2 emissions and studies the dynamic relationship and spatial spillover among economic growth, energy consumption, and CO2 emissions effects. The results show that the economic growth can significantly improve carbon dioxide emissions, and China's economic growth level has become a positive driving force for carbon dioxide emissions. However, economic growth will not be significantly affected by the reduction of carbon dioxide emissions. There is a two-way relationship between energy consumption (ENC) and carbon dioxide emissions (CO2). Energy consumption and carbon emissions are interrelated, which has a negative spatial spillover effect on the carbon dioxide emissions of the surrounding provinces and cities. [ABSTRACT FROM AUTHOR]

In this paper, the maximum entropy model (Maxent) and geographic information system ( ArcGIS 10.3) softwares were used to predict the potential distribution areas of four Litsea species under the current and future climate conditions of China ( 2061 - 2080), and to analyze and classify their suitable habitats. The results were as follows: Litsea cubeba was widely distributed in the south to the Yangtze Hiver in China, and under the future climate with two ( HCP2.6, HCP8.5) carhon dioxide concentrations, during 2061-2080 the suitable anca for its distribution was reduced by 4.9%and 0.5%, respectively; L. coreana was mainly distributed in central and northern subtropical regions of China, and under the climate scenarios with two carbon dioxide concentrations, in 2061-2080 the total suitable area would be increased by 5.6% and 4.5%, respectively; L. greennumiana was mainly distributed in the south subtropical regions of China; L. mollis was widely distributed in the subtropical region. Under the future climate HCP2. 6 scenarios, the suitable area of the two species would be shrinked by 1.0% and 3.3%, respectively, and under the climale HCP8.5, the suitable area of the two species would be shrinked by 5.6% and 8.3%, respectively. These results reveal that due lo different ecological requirements, Litsea species will have different distributional responses to the future climate. the introduction and cultivation of Litsea species should consider the influences of climale change. [ABSTRACT FROM AUTHOR]

The current study proposed the improved non-linear multi-variable Grey Bernoulli model and predicted the CO2 emissions in China. Firstly, the paper presents an improved multivariate grey Bernoulli model (INGBM(1, N)) that considers the nonlinearities of the system characteristic data and related factors in establishing the grey model. Secondly, the influence of the relevant factors on the grey model's forecast accuracy has been considered. The more the number of relevant factors, the higher the relative level with the system characteristic data, the higher the calculation accuracy. However, predictive accuracy began to decrease again after the number of relevant factors more than a specific value. Thirdly, we selected the number of relevant factors as 4 (coal energy consumption, urbanization rate, crude oil, population) and carried out compared analysis with other grey models and non-grey models. The results show that the proposed model has the best forecasting accuracy. The proposed model is a generalization of several other grey forecasting models. China's COz emissions for 2019-2021 is forecasted. It estimated that the value would continue to increase over the next three years and reach 9958.57Mt by 2021. Finally, several measures have briefly mentioned reducing COz emissions based on the influence of relevant factors. [ABSTRACT FROM AUTHOR]

An evaluation system has been established for assessing carbon dioxide emissions associated with asphalt pavement construction in China. As described in this paper, the system is based on the European driving force–pressure–state–impact–response model and uses the analytic hierarchy process combined with subjective and objective weighting and the comprehensive index method. It shows that state, response and pressure are the decisive factors. As such, the key factors that promote lower carbon dioxide construction of asphalt pavements are expressway construction investment, asphalt consumption, greenhouse gas effects, environmental quality and energy-saving and emissions-reduction technology. It is suggested that energy-saving and emissions-reduction technologies, such as warm mixing and geothermal regeneration, should be adopted in the construction of asphalt pavements and the concept of low carbon dioxide approaches should be promoted. The findings can provide technical support for decreasing the energy consumption and emissions in asphalt pavement construction. [ABSTRACT FROM AUTHOR]

Coal seam with low permeability is widely distributed in China. Injection of flue gas (N2:CO2 = 0.85:0.15) is an effective approach to improve coal seam gas drainage efficiency. This process relates complex responses among ternary gases (CH4, CO2, and N2) competitive sorption on coals, gas diffusion, gas‐water migration by means of two‐phase flow, and coal deformation. In this paper, an improved hydraulic‐mechanical model coupling above interactions is established for flue gas injection enhanced gas drainage. This model is used to simulate flue gas enhanced drainage by finite element method. The sensitivity analyses of key factors are made to recovery a better understanding on the processes controlling flue gas enhanced drainage. Results show that the flue gas enhanced drainage can indeed improve the efficiency of gas extraction and reduce the gas pressure to the required value in a shorter duration. Due to the competitive adsorption and gas sweeping effect of injected flue gas, CH4 is driven toward drainage borehole, and CH4 pressure and content near the injection borehole decrease faster than that near the drainage borehole. The peak CH4 pressure laterally moves from the injection borehole to the drainage borehole. Higher injection pressure, initial permeability, and smaller sorption affinity ratios may lead to greater CH4 production rate at early drainage stage, but smaller CH4 production rate at late stage. The factors controlling the behavior of flue gas enhanced drainage are initial permeability, injection pressure, and sorption affinity ratios in order. This work offers useful framework to investigate important technical challenges associated with enhanced mine gas drainage, as well as unconventional gas development. [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]

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]

[Display omitted] To achieve carbon neutrality, it is urgent to quantify carbon emissions to support policy deployment. Based on life cycle assessment, this paper proposed calculation method for carbon emissions from road infrastructure in a Demonstration Zone, China. Based on scenario analysis, this paper quantified the carbon emissions currently and analyzed the trend and characteristics of carbon emissions of road infrastructure from 2020 to 2060 through 4 scenarios. The results show the carbon emissions fluctuate between 20 kt and 540 kt CO 2 from 2013 to 2019 and increase significantly in 2014 due to the surge in road mileage. In the first three scenarios, the carbon emissions show an increasing trend after 2030, with annual growth rates of 1.12%, 0.57%, and 0.27% respectively. However, in the optimal scenario, the peak year of carbon emissions is 2024, with the peak emissions of 649.333 kt CO 2 and an increase of 245% over the base year. [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]