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Mangroves, as a crucial coastal ecosystem, possess significant carbon sink functions and play a key role in mitigating global climate change. This paper, based on the Zhanjiang Mangrove Afforestation Project in Guangdong, explores the development mechanisms and economic and ecological benefits of mangrove carbon sink projects through the lens of collective action theory and system dynamics modeling. The study finds that the primary reason for the unsustainable progression of mangrove carbon sink projects is the lack of intrinsic motivation among local villagers to engage in collective action. By constructing a system dynamics model, this paper quantifies the long-term impacts of mangrove carbon sink projects on local socio-economic welfare and proposes policy optimization recommendations. These recommendations include expanding income sources for local villagers, establishing carbon trading and ecological compensation mechanisms, and involving international non-governmental organizations. The findings of this study not only provide guidance for mangrove carbon sink projects in China but also offer valuable insights for the promotion of similar projects globally. [ABSTRACT FROM AUTHOR]

With the increasing severity of global warming, the goal of carbon sequestration and emission reduction in various industries has become an important responsibility for sustainable development. As an important part of carbon sink, the improvement of net carbon efficiency in the plantations industry will make a great contribution to the realization of the "double carbon" target in agriculture. However, there are large spatial and temporal differences in the net carbon efficiency of the plantations sector in various provinces, and there is still a large scope for increasing carbon sink and reducing carbon emission. In this paper, we have analyzed spatial and temporal trends in the net carbon sink efficiency of the plantations' production processes in 31 provinces in China (excluding Hong Kong, Macao and Taiwan) from 2000 to 2020. On this basis, we have analyzed the influencing factors of net carbon efficiency in the plantations' production process through an extended Kaya constant equation. Through the geographically and temporally weighted regression model, we explore the spatio-temporal heterogeneity of the influencing factors, and further analyze the driving and restraining factors of net carbon efficiency in plantations' production process, in order to propose appropriate countermeasures. The study shows that: (1) The net carbon efficiency of plantations sector in China increase between 2000 and 2020, and the development of net carbon efficiency is uneven across regions. (2) The geographic center of net carbon efficiency of China's plantations industry shift from the northeast to the southwest and is consistent with the migration direction of agricultural inputs. (3) The influencing factors of net carbon efficiency in the plantations sector show large regional differences, and can be specifically divided into four major types of zones. In this regard, this paper provides more appropriate countermeasure suggestions for increasing carbon sink and reducing carbon emission in each zone, with a view to achieving the goal of double carbon in agriculture with practical significance. • Net carbon efficiency is a new objective indicator to measure the carbon sink level of cropland. • Cultivated land carbon sink capacity is closely related to agricultural inputs. • Regional differences in the factors influencing net carbon efficiency. [ABSTRACT FROM AUTHOR]

China has committed to peak carbon emissions by 2030 and become carbon neutral by 2060. Hebei, as a major energy province in China, has more challenging carbon peaking and carbon neutrality targets. Based on the extended STIRPAT model, this paper evaluates the time to peak carbon and post-peak carbon trend changes in Hebei province under different scenarios from 2020 to 2060. Based on the support vector machine model with particle swarm optimization, this paper evaluates the carbon neutral pathways under different scenarios in Hebei province from 2020 to 2060 in terms of forests, croplands, wetlands, grasslands and Carbon Capture, Utilization and Storage (CCUS). The results show that a monotonically flat trend without inflection point, a single-inflection-point plateau-period trend and a multi-inflection-point inverted U-wave trend occur after carbon peaks. Hebei Province can achieve carbon neutrality by 2060 under the policy scenario and the enhanced scenario, and the enhanced scenario is better. Comparing with existing studies, the innovation of this paper is to design different trends of changes after carbon peak, combining carbon absorption and carbon emission, and providing more diversified development paths for carbon neutral strategies through a more integrated perspective and multi-scenario comprehensive analysis. Therefore, In the future, Hebei Province should establish a platform for carbon emissions monitoring and carbon footprint assessment, and set up an early warning and assessment mechanism for carbon peaking, so as to prevent a rebound trend in carbon emissions after peaking. At the same time, it should introduce and develop carbon capture and conversion technologies and promote the low-carbon transformation of the industrial and energy sectors, thereby forcing the early realization of peak carbon. Pay attention to the role of forestry resources in carbon neutrality, increase carbon sink resources such as forests and wetlands, promote the development of CCUS, and enhance the implementation of the policy. [ABSTRACT FROM AUTHOR]

In 2020, China formally proposed the goal of achieving carbon peaking in 2030 and achieving carbon neutrality in 2060. Since then, widespread attention has been devoted to determining when and how this goal will be achieved. This paper creatively puts forward the view of low-carbon digital economy from the perspective of resource flow, digital flow and energy flow, and studies the synergy effect of low-carbon digital development by constructing the synergy model of low-carbon digital development economic and social development. Based on theoretical research, this paper constructs a synergy model and evaluation index system between low-carbon digital development and economic and social development, and an empirical analysis was conducted based on data related to regional low-carbon digital development and economic and social development in China from 2014 to 2019. The empirical results show that the development of China's low-carbon digital economy is the main driving force for future economic and social development. The effects of low-carbon digital economy on economic and social development varied across regions due to their different regional development patterns. The spatial pattern shows a trend of "high in the east and low in the west". Further, if the low carbon economy and the digital economy included in the stimulus policies can play a synergistic role, it will be able to play the greatest role in promoting economic and social development. And such a scenario is used as a practice in different regions of China in future. The research conclusion of this paper enriches the discussion on the construction of ecological civilization and the construction of a community with a common future for mankind. The conceptualized model of low-carbon digital economy and economic-social development. [Display omitted] [ABSTRACT FROM AUTHOR]

Robust carbon reduction strategies are needed to meet climate targets, especially for emissions from building materials. Although research has shown that the production of materials can be influenced by local conditions, such as the energy mix, the impact of regionalization on embodied emissions from buildings has not yet been fully explored. In this paper, we investigate the impact of inventory regionalization on the life cycle assessment of buildings and its influence on greenhouse gas (GHG) reduction strategies. This is performed by first developing a consistent, automated and reproducible method for regionalizing the production process of building materials for all countries. We then apply life cycle assessment to a building for all European countries using the created regionalized processes. The results show strong deviations for certain countries, reaching a difference of up to 17% to the regional average data. When investigating the influence of regionalization on the choice of typical GHG reduction strategies, results show that the choice of strategy can be influenced by the regional context, supporting the need for greater geographic representativeness of building materials inventories for successful GHG emissions reduction pathways. Regionalization can also support the development of more accurate product-specific environmental product declarations (EPDs), which currently rely on average background data. • Influence of inventory regionalization on building LCA is demonstrated. • A method is created to systematically regionalize the ecoinvent database. • A difference up to 17% is observed when performing a building LCA. • Regionalization can also support higher accuracy of EPDs. • GHG reduction strategies are strongly influenced by the regionalization. [ABSTRACT FROM AUTHOR]

The significant carbon emissions generated by China's sludge treatment industry cannot be ignored. However, with only a few recent well-executed studies on carbon emission reduction in the sludge treatment field, the literature awaits a more comprehensive assessment and prediction whether the sludge treatment industry can achieve the dual-carbon target. This article aims to fill this gap, holistically examining the carbon emission reduction potential in the industry. Using the moving average method and IPCC method, the projected carbon emission value of sludge treatment in China from 2021 to 2030 indicates a total net carbon emission of 0.3 million tons by 2030. This suggests that the sludge treatment industry is on track to meet the carbon peak target, leaving surplus carbon quotas or credits available to assist other industries for carbon emissions reductions. The study also finds that only incineration and composting demonstrate the potential to be able to partially offset carbon emissions through resource utilization in certain stages or processes. Therefore, the current sludge treatment methods do not yield comprehensive emission reduction effects and cannot provide sufficient contribution to China's dual carbon goals. To address this issue, the paper explores a new scheme that focuses on improving the sludge treatment process. The scheme comparative analysis reveals that, even with all sludge treatment methods optimized, the total net carbon emissions of the industry could only be reduced to 0.058 million tons. This reduction falls short of significantly mitigating carbon emissions to achieve the carbon neutrality goal. Therefore, industries unable to achieve substantial net carbon reduction may need to explore alternative measures, such as carbon sinks, to ultimately attain carbon neutrality. [ABSTRACT FROM AUTHOR]

An emerging strategy to remove CO 2 from the atmosphere and compensate for the greenhouse-gas emissions of cement and concrete is based on incorporating biochar into concrete. With this approach, concrete can be turned into a functional carbon sink (C-sink). Until now, biochar has been mainly used without modification to replace part of the cement or of the aggregates in concrete. However, this technology comes with a number of practical problems, which include the high water absorption of the biochar (due to its high specific surface) and hazards (dust, risk of combustion). In this paper we present an alternative approach, in which biochar is first processed into lightweight aggregates in a cold-bonding process. To this end, biochar is pelletized together with water and a small amount of hydraulic binder forming round pellets that further harden with hydration. In this way, carbon-rich lightweight aggregates (C-LWA) are obtained that are easier to handle than the original biochar. The C-LWA pellets have similar porosity and strength as conventional LWA and can be used for similar applications. Yet, the CO 2 emissions from sintering traditional LWA are avoided and the C-LWA are instead an effective C-sink. We demonstrate that it is possible to incorporate in the pellets and eventually in the concrete a sufficient amount of carbon to compensate for the original emissions of concrete. The net-zero emissions concrete obtained with this approach possesses mechanical performance sufficient for typical structural applications in buildings. • Biochar is processed into lightweight aggregates in cold-bonding process. • The biochar-rich lightweight aggregates added to concrete act as a safe carbon sink. • Structural concrete with net-zero greenhouse gas emissions becomes possible. [ABSTRACT FROM AUTHOR]

Soil respiration is the process of decomposition of organic matter in soil and microbial metabolism to produce carbon dioxide. In the context of climate warming and degradation of agricultural soil fertility, it becomes crucial to explore the mechanisms of soil respiration to increase carbon sequestration. In this paper, five biochar applications (0, 3.79, 7.58, 11.36, 15.15 t/ha) and two tillage methods (shallow ploughing, deep ploughing) were set up to explore the mechanism of soil respiration and its temperature sensitivity by studying the effects of tillage methods and different amounts of biochar application on soil properties, soil enzyme activities, soil respiration and its temperature sensitivity during the growing season of soybeans in the black soil area. The results showed that soil respiration rate increased with biochar application in the low biochar application range; the opposite trend was observed for high biochar application beyond the threshold (11.36 t/ha). The application of 11.36 t/ha of biochar amount had the strongest promotion effect on soil respiration, reaching 2.42 μmol m−2·s−1 in the shallow ploughing treatment and increasing 0.32 μmol m−2·s−1 in the deep ploughing compared to the shallow ploughing. The application of biochar significantly increased the activity of nitrogen and phosphorus enzymes and had an inhibitory effect on carbon cycle enzymes; the increased activity of nitrogen and phosphorus cycle enzymes provided sufficient substrate for microbial respiration and thus increased soil respiration, and the decrease in the enzymatic reaction of carbon cycle enzymes led to a decrease in temperature sensitivity. The temperature sensitivity of deep ploughing (2.18–2.59) got a more substantial reduction than that of shallow ploughing (2.34–3.53), which indicates that deep ploughing treatments can better reduce the mineralization of organic carbon than shallow tillage. Meanwhile, the temperature sensitivity of soil respiration reached a minimum with the application of 7.58 t/ha of biochar, which was reduced by 16% under deep ploughing treatment compared to the control, 33% under shallow ploughing treatment compared to the control, and also reduced by 27.27% under deep ploughing compared to shallow ploughing, which suggests that the addition of biochar reduces the loss of carbon to a certain extent. This study is important for assessing the effects of tillage practices and biochar combinations on carbon sequestration in agricultural soils in black soil areas. Note: Upward arrows indicate an increase, downward arrows indicate a decrease, and the thickness of the line characterizes the degree of strength; SP and DP represent shallow and deep ploughing treatments. [Display omitted] • DP applied 7.58 t/ha of biochar reduced Q 10 by 16% compared to the control. • The Q 10 of DP is reduced by 36.29% relative to SP without the application of biochar. • Soil enzyme activity enhances soil respiration but reduces temperature sensitivity. [ABSTRACT FROM AUTHOR]

This paper examines the potential for property rights in carbon to affect industrial ecology opportunities. Given that emissions trading schemes for greenhouse gases are becoming more widely implemented, the definition of the carbon property right can affect barriers and opportunities for industrial ecology, alongside other factors. The paper uses legislation for emissions trading in Australia and two possible scenarios for the future of energy generation in the Latrobe Valley, Australia in 2050 as an illustrative case study to identify issues for industrial ecology arising from ill-defined carbon property rights. Currently, electricity generation in the region is reliant on coal-based generators. Scenario one focuses on bio-industries and renewables with no coal usage; and scenario two focuses on electricity from coal with carbon capture and storage resulting in moderate to high coal use. If a carbon property right for soil carbon emerges before a property right for subterranean carbon, then bio-based industrial ecology opportunities could be enabled ahead of a regional symbiosis involving carbon capture and storage. A generalised framework for considering the intersection of industrial ecology and carbon property rights is presented with a focus on tensions in: contributing to sustainable development, system boundaries and finally exchange mechanisms. [ABSTRACT FROM AUTHOR]

Reducing environmental pollution, developing and utilizing low-carbon integrated energy system, making economic development maintain a good momentum of sustainable development, has become hot issues of energy research around the world. The Multi-energy Complementary Distributed Energy System (MCDES), that can not only meet the changing energy supply structure and user demand, but also promote the efficient use of resources in the energy system and low-carbon environmental protection, has become the main direction of future energy development. The energy units in MCDES often have large time scale difference and strong uncertainty, which makes the planning and operation of the system more complex than the traditional energy system. Research on the characteristics of system configuration and operation optimization is one of the key measures to ensure the sustainable development and effective utilization of MCDES. Therefore, from three aspects of low-carbon, life cycle and optimization method, the MCDES life cycle low-carbon optimization method is studied in this paper. By reviewing the low-carbon optimization, life cycle optimization and system optimization methods of MCDES, the main problems in the current research status of MCDES life cycle low carbon optimization are pointed out. On this basis, according to low carbon measures and life cycle coordination theory, a multi-objective collaborative optimization method for MCDES life cycle planning and operation is proposed. The research content of this paper provides theoretical guidance for MCDES design optimization. [ABSTRACT FROM AUTHOR]

Due to unclear research boundaries and a confusion between direct and indirect emissions, the impact of the circular economy (CE) on carbon emissions needs to be researched in depth. In this paper, we use a life cycle model based on carbon emissions and carbon reduction to build an emissions (reduction) matrix for the carbon footprint (CF) of coal-fuelled power generation, and then calculate the life cycle carbon emissions from China's coal-fuelled power CE parks. Results show that carbon emissions from China's coal-fuelled power at the industrial park level follow the trend of raw coal production and consumption, increasing from 2000 to a maximum of 3.25 billion tCO 2 e in 2014, with the proportion of direct emissions remaining stable at above 86%. The life cycle CF in 2016 was 778.9 gCO 2 /kWh, a decrease of 20.81% compared to 2000. The positive and negative impacts of the CE from 2000 to 2016 were quantitatively analysed, and resource recycling measures will reduce the overall carbon emissions of industrial parks through the substitution of carbon-intensive energy sources. Finally, policy recommendations are proposed to reduce life cycle carbon emissions by energy replacement and embodied emissions control. The novelty of this study is the quantitative evaluation of indirect carbon emissions caused by the CE and determining the correlation between CE and carbon emissions reduction. • Highlight the indirect impact of the circular economy on carbon emissions. • Evaluate the carbon footprint (carbon emissions and reduction) of coal-fuelled power. • The life cycle carbon footprint decreased by 20.81% between 2000 and 2016 to reach 778.9 gCO 2 /kWh. • Circular economy had an overall net reduction in carbon emissions. [ABSTRACT FROM AUTHOR]

Carbon sink is an effective measure to balance the contradiction between economic development and mitigating climate change in China. This paper reveals that environmental performance of forest carbon sinks reflects in economic value by reducing the emissions abatement cost. The carbon trading system is used to demonstrate the environmental and economic value of forests. The forest carbon sequestrations are estimated and predicted in different regions of China. Furthermore, a market model has been established to assess how the emission reduction costs can be reduced among all regions by the year 2030 to achieve the goal of carbon emissions intensity in China. The results show that carbon sequestration trades can reduce the emissions reduction costs and it can represent the value of forest carbon sinks. In particular, when economic growth is maintained in moderate and low level in China, the national carbon trading market with carbon sequestration will decrease the carbon emissions reduction costs more effectively. Besides, carbon sink can bring economic benefits to under-developed regions where there are rich forest resources. Image 1 • Carbon sinks are coordination between the environment and the economy. • Carbon sinks can be valued by emissions trading market. • Forest carbon sinks help to achieve carbon emissions reduction targets. • Forest carbon sinks promote economic development in some backward areas. [ABSTRACT FROM AUTHOR]

This paper proposes a novel biomass-fueled sustainable cogeneration power cycle with hydrogen production via a PEM electrolyzer. In this system, exiting product gases from the combustion chamber undergoes a CO 2 capture process utilizing LNG regasification to avoid CO 2 emissions to the atmosphere. Since biomass has a lower emission rate compared to fossil fuels and is subject to easier replacement and conversion, this system is considered to have a zero CO 2 emission rate. LNG is the only cooling medium in this system; no exterior fluid like water is used to cool the system, making the overall process more environmentally friendly. This present system offers a unique structure utilizing renewable technologies for future zero-emission power layouts with sustainable and clean commodities such as green energy and hydrogen. A parametric study for this system is performed and results of energy and exergy analyses are presented to depict a better view of the system's performance and its advantages. The system includes a gas Brayton cycle as the main cycle, a LNG expander, as well as one steam Rankine and three organic Rankine cycles as bottoming cycles. Generated power from the organic Rankine cycles and LNG expander is allocated to the PEM electrolyzer for green hydrogen production. Municipal waste is the sole source of fuel for this system; a downdraft gasifier is used to convert it to syngas for combustion. For a fixed net power generation rate (10 MW), of which a portion is fed to the electrolyzer, the system consumes around 0.66 kg/s of municipal waste, and captures around 1.32 kg/s of CO 2 using LNG regasification. Energy and exergy efficiencies of 84% and 50% respectively as well as 47 kmol/h green hydrogen generation are achieved. • Municipal waste is used as the sole fuel via a downdraft gasifier. • Green hydrogen is produced utilizing a PEM electrolyzer. • The CO 2 capture process is performed using LNG regasification. • Regasified LNG is used as a working fluid for power generation. • The system is simulated and analyzed from a thermodynamic perspective. [ABSTRACT FROM AUTHOR]

Gas flaring has many environmental impacts at global and local scale. Conversion of associated gas into 1-propanol (scenario PRL) and propylene (scenario PRE) via the C123 process can be a potential solution to prevent combustion. This paper aims to evaluate the environmental performance of C3 production from associated gas compared to flaring and to identify the preferred C3 chemical for associated gas conversion. A carbon substance flow analysis (CSFA) and a life cycle assessment (LCA) were conducted. CSFA was used to map all carbon flows and to calculate the carbon emission savings and carbon efficiency. The LCA focused on the impact categories climate change, fossil resource use, human toxicity and the cumulative exergy extraction from the environment. The results of the CSFA indicate that 2.89 kg CO 2 per kg associated gas could be saved in scenario PRL, when including the avoided conventional C3 production in the analysis. The LCA shows that scenario PRL outperforms flaring for climate change and human toxicity. Consequently, 1-propanol production from associated gas is the preferred alternative at the selected location. Heat integration and renewable electricity production can drastically decrease the impact of C3 chemicals production on climate change and enable CO 2 emissions savings compared to flaring. [Display omitted] • The sustainability of associated gas conversion into C3 chemicals was studied. • A carbon substance flow analysis and life cycle assessment were conducted. • C3 production outperforms flaring for climate change and human toxicity. • Resource use is lower than reference for 1-propanol production from associated gas. • The production of 1-propanol from associated gas is preferred above propylene. [ABSTRACT FROM AUTHOR]

In the last years, carbon ceramic brakes are preferred to traditional cast iron ones for their lightweight, high temperature resistance, and long service life, even though their manufacturing involves the use of high temperature processes and energy-intensive materials such as carbon fibers. Within the European Life Project "CIRCE", a novel recovery system for carbon fiber prepreg scraps was developed to reclaim high-quality carbon fibers to use as a substitute of virgin carbon fibers in different application, such as in Ceramic Matrix Composite (CMC) brakes. In order to overcome the lack of scientific literature regarding the environmental sustainability of steel and CMC brakes, in the present paper, the Life Cycle Assessment (LCA) methodology was applied to carry out a detailed analysis of the environmental impacts associated with carbon ceramic brakes realized using the reclaimed prepreg scraps. The functional unit was defined as production, use and disposal of a rear brake disc used for the deceleration of a sport car during its lifetime. Different impact indicators were considered, such as Global Warming Potential, Cumulative Energy Deman and ReCiPe midpoint categories. The results were compared to those given by the sustainability assessment of cast iron disc brakes and traditional carbon ceramic brakes. The proposed LCA is a cradle to grave analysis, as it considers all the relevant inputs and outputs of the manufacturing processes, from the raw material extraction to the materials disposal. The surface of ceramic brakes was observed using Scanning Electron Microscopy to assess the different material structures. The results show that, as far as the production is concerned, cast iron brakes are the most sustainable alternative, with impacts lower than 21% of the composite component ones. However, if a long use phase more than 200,000 km is evaluated, carbon ceramic brakes obtained by reclaimed prepreg scraps are characterized by lower environmental impacts, with impacts that are about 8% lower than those obtained by traditional carbon ceramic brakes. [Display omitted] • Environmental assessment of cast iron and Ceramic Matrix Composite brake discs. • Use of recovered prepreg scraps in substitution for virgin carbon fibers. • The use of recovered prepreg scraps improves the sustainability of composite parts. • Recovered material CMC brakes can be more sustainable than cast iron brakes. [ABSTRACT FROM AUTHOR]

Municipal solid waste management is a major environmental issue facing modern cities due to risks posed to humans and emissions of greenhouse gases. In China, landfills are among the main management options used in urban centers. Other options for municipal solid waste treatment include waste minimization, material recycling, and recovery of energy. An integrated municipal solid waste management system must utilize these alternatives in an optimal manner while accounting for system constraints. This paper presents a hybrid approach for planning a carbon-constrained municipal solid waste management system for Qingdao City. The method is based on Life Cycle Carbon Accounting and Carbon Emission Pinch Analysis. First, the amount of carbon emissions released during municipal solid waste treatment in Qingdao City is calculated using Life Cycle Carbon Accounting. Then, Carbon Emission Pinch Analysis is conducted to evaluate management options for treatment of municipal solid waste under specified emissions targets. Four scenarios are assessed wherein alternative combinations of municipal solid waste treatment methods are combined for the case of Qingdao City. [ABSTRACT FROM AUTHOR]

Limiting the negative effects of human-induced global warming is the focus of climate policy worldwide. In the European Union (EU), the target for reaching carbon neutrality is set to 2050, including a proposed renewable energy target of 45% for 2030. In Finland, the government has pledged to reach net-zero emissions already by 2035, which is expected to require large increases in wind and nuclear capacity, as well as sector coupling with, e.g., transport and heating. In view of these plans, this study evaluates the feasibility of attaining carbon neutrality in Finland by 2035, while considering delays from potential bottlenecks, such as limited raw material availability, fuel availability, manufacturing capacity, and import reliance. The literature review highlights the considerable dependence of renewable technologies on critical raw materials and other minerals, largely imported from non-EU countries. Modelling revealed how increased biomass usage considerably reduces the size of national carbon sinks, vital for reaching net-zero emissions in Finland in the coming decade. In light of this, current climate strategy was shown to be partially outdated and short of reaching carbon neutrality by 2035, already without including potential delays from the analyzed bottlenecks. Subsequently, alternative measures to improve sustainability and reduce emissions are presented. The findings of this paper are also relevant for other countries aiming to reach net-zero emissions, especially for those which have climate strategies emphasizing bioenergy and wind power. [Display omitted] • Raw material and manufacturing bottlenecks can delay renewable implementation. • Maintaining carbon sinks critical for climate neutral Finland in 2035. • Limits to biomass usage are needed, but result in adverse industrial impacts. • Further nuclear capacity needed for 2035 climate target and electricity sufficiency. • Finland will rely on electricity imports in 2035, despite plans to become exporter. [ABSTRACT FROM AUTHOR]

The industrial revolution has brought about great development in the economy, but it has also increased the dependence on fossil energy. The emissions of CO 2 and other greenhouse gases have contradicted economic development and the ecological environment. The establishment of the EU Emission Trading System (EU ETS) has improved the global carbon emission price mechanism, but as a new commodity, its price trend will affect buyers' risk evaluation. Therefore, it is influential to master the driving factors behind carbon emission prices and make effective predictions. First, the paper points out that the driving factors are divided into macroeconomic risk factors and energy factors. Second, the Bayesian Network is used to select variables and make prediction of carbon prices. The results show that its accuracy exceeds other machine learning algorithms. Third, a structural equation model is used to study the impact of the selected markets on the carbon market. Finally, from the perspective of global carbon emission reduction, the relationship between driving factors and the carbon futures market is explained. The empirical results show that Cotation Assistée en Continu 40, natural gas and Brent crude oil will directly affect the yield of European Union Allowances and Certified Emission Reduction futures, and the Standard Poor 500 and Global Clean Energy Index will indirectly affect the yield of European Union Allowances and Certified Emission Reduction futures. The energy market will affect the carbon market through the intermediary effect of the stock market, in which the clean energy index is the most relevant factor. From the perspective of how to improve the carbon trading system, this paper proposes suggestions for the sustainable development of the world to promote the virtuous cycle of the global carbon emission market and the high-quality development of the global economy. • Multimarket Carbon Factor Selection Model. • Forecasting Carbon Market Price by Bayesian Network. • Markets Impacts Research and Path Analysis with Structural Equation Model. • Clean Energy Investment and Global Energy Structure Analysis. [ABSTRACT FROM AUTHOR]

Crop production not only creates economic values, but also has ecological functions. The carbon sink function of crops plays an important role in mitigating climate changes. This paper collected and analyzed the carbon cost data of staple crops in China, estimated the carbon sink and carbon source effects of farmlands, and quantitatively evaluated the carbon inputs and outputs of crop production systems. The results showed that the carbon footprints of crops in six typical agriculture regions were quite different, and the major crops production showed as carbon sinks in general. The carbon sequestration of different crops in the same region were significantly different, as well as the same crop in different regions. China’s farmland ecosystem showed carbon sequestration effect: the total annual net carbon sink of three major crops, rice, wheat, and corn, was about 165.76 TgC, of which rice was the highest, accounting for 48.71%. This study also proposed the key ways for energy conservation and emission reduction of crop production in every region, and suggested the technology direction for improving carbon sink function. This study provided important basis for policy formulation and planning about the low-carbon agriculture development in China. [ABSTRACT FROM AUTHOR]

Nowadays it is estimated that the Earth's temperature is above the standard level compared to pre-industrial time. The main reason for this issue is the burning of conventional energy resources namely oil, gas, and coal which speeds up global warming. In this concern, a CHP-based multi-energy microgrid is studied in this paper which involves heating, cooling, and electricity carriers to supply the energy demands. The proposed system is a multi-objective problem with operation cost management and emission cost reduction. In order to develop the environmental and economic aspects, a power-to-gas (P2G) technology as an environmentally friendly system is taken into account to curb CO2 emissions and achieve a sustainable function. The presence of the P2G system can minimize the emission level and improve the ability to take advantage of Notwithstanding this, the uncertain parameters originate from the thermal, electrical, and cooling loads, electricity price, and the renewable generations impose inflexibility and financial threats to the system function. In this regard, a scenario-based risk assessment approach, p-robust optimization, is applied to handle these uncertainties. The uncertainty analysis is carried out in With-p-robust, No-p-robust, With-P2G, and No–P2G models to appraise the components' performance. Results showed 11% of the operation cost increment to achieve a zero-level risk. Also, 55% of the emission cost is minimized in the presence of the P2G facility, which enhances the efficiency of the system. [Display omitted] • Optimal multi-objective operation of CHP-based multi-energy microgrids with emission constraints. • Use of P2G facilities for carbon recycling and emission reduction. • Scenario generation and reduction through the stochastic programming for uncertainty modeling. • Modeling the regret of uncertainties using the hybrid modeling approach called p-robust optimization. [ABSTRACT FROM AUTHOR]

China has proposed to achieve the carbon neutrality target by 2060. It is important for China to clearly understand the carbon sink of ecosystems. Most current studies focus on accounting for the carbon sink or carbon emission in the past and ignore the contribution of ecosystems to carbon neutrality in the future. The work presented in this paper projects land use changes in 2030 and 2060 under the business as usual (BAS), rapid economic development (RED), and ecological land protection (ELP) scenarios based on Multiple Objective Programming and GeoSOS-FLUS and calculates the carbon budgets and contributions of ecosystems to carbon neutrality in Qinghai during 2000–2060. The key findings are that the contributions of the terrestrial ecosystem to carbon neutrality in Qinghai are 9.92% (BAS), 10.03% (ELP) and 7.56% (RED) in 2030, and 3.23% (BAS), 3.28% (ELP) and 2.91% (RED) in 2060. These results indicate that the Qinghai ecosystem has carbon sink potential and the reduction of carbon emissions by humans is the core challenge in achieving carbon neutrality. Therefore, some recommendations have been made: 1) optimizing the land use structure to enhance the ecosystem sink in Qinghai; 2) continuing to implement the policies of ecological protection in Qinghai; 3) reducing the anthropogenic carbon emissions is the key to achieving carbon neutrality in 2060. This study not only offers data support and related policy recommendations to realize carbon neutrality goals but also provides a feasible method for future ecosystem contribution assessments under the goal of carbon neutrality. • Current land use policies in Qinghai are partial to ecological land protection. • Terrestrial ecosystem contributions to carbon neutrality are decreasing. • Terrestrial ecosystem contributions are similar in 2060 under three scenarios. • Carbon emission reduction of social system is key to achieving carbon neutrality. [ABSTRACT FROM AUTHOR]

In the social context of mitigating climate change and achieving carbon neutrality, the improvement of carbon emissions efficiency and the protection of biological carbon sequestration have emerged as hot topics recently due to their prospects in carbon dioxide emissions reductions. A large volume of studies has identified the spatial distribution characteristics and influencing factors of carbon emissions efficiency. The contributions of our study lied in constructing a system to measure net carbon sink efficiency. Secondly, this study discussed the carbon neutrality performance of Chinese cities from three different aspects of carbon dioxide emissions, carbon sequestration of vegetation and net carbon sink efficiency. Thirdly, this paper identified the influencing factors of net carbon sink efficiency, and examined the direct and indirect effect of different factors. For this purpose, we evaluated the net carbon sink efficiency of 285 cities in China from 2012 to 2017 using a slacks-based measure model, and explored its spatial distribution characteristics, then employed a spatial Durbin model to explore the influencing factors of net carbon sink efficiency. Our main findings indicate that the net carbon sink efficiency steadily increased during the study period, whereas their spatial characteristics were "high at both ends and low in the middle" from the south to the north. There is a significant spatial autocorrelation in the net carbon sink efficiency of Chinese cities. Several kinds of measures can be applied to promote net carbon sink efficiency, such as increasing the proportion of tertiary industry, promoting economic growth, attracting foreign direct investment, increasing road area, promoting technological progress and strengthening environmental regulation. However, the increase of urban population may decrease efficiency. Nevertheless, an obvious spatial spillover effect exists in the net carbon sink efficiency of Chinese cities. The results can provide policy recommendations for the government to formulate differentiated carbon neutralization policies. [Display omitted] • The carbon sequestration is considered to calculate net carbon sink efficiency (NCSE). • The NCSE is used to discuss the carbon neutral performance of Chinese cities. • Chinese NCSE steadily increased and showed significant spatial autocorrelation. • Spatial Durbin model was adopted to study the influencing factors of NCSE. [ABSTRACT FROM AUTHOR]

The emerging effects of climate change caused by the rise of carbon dioxide (CO 2) and equivalent greenhouse gas (GHG) emissions to the atmosphere have prompted policymakers to revise current emission reduction schemes. One of the schemes is a carbon permit scheme which places a restriction on the CO 2 or equivalent GHG emissions to the atmosphere. However, limited literature explores the effectiveness of sharing carbon permits in an IS system to optimise and reduce waste emissions in a system. Therefore, this research presents an optimisation-based framework for plants in an industrial symbiosis (IS) system with a carbon permit scheme. The critical success factor for an IS system is the collaboration and synergistic possibilities between participating plants within geographical proximity. This paper takes a different approach from the typical physical resource sharing in IS. This research considers carbon permits as a shared resource between the plant operators. The sharing of carbon permits creates a cooperative environment between the plant operators in the IS system. Through this system, cooperative game theory (CGT) was used to determine the fair allocation of profit to each participating plant operator based on their marginal contribution in the IS system. A case study has been implemented for three process plants: palm oil mill (POM), palm oil-based biorefinery (POB) and combine heat power (CHP) plant that are operated under a carbon permit scheme. Results from the base case study illustrates that each plant operator receives an average of 12% higher profit when sharing their carbon permits relative to working individually under the carbon permit scheme. A further analysis has been conducted to investigate the framework′s economic feasibility at different emission cuts. With differing emission cuts, the results indicated plant operators obtained an increase in their profit margin by 25% when working in a coalition relative to working independently. • Sharing of carbon permits in industrial symbiosis system (IS) with cooperative game theory. • Reducing carbon emission in a system through cooperative games. • Sharing of resources for plants that are not within geographical proximity. • Linear mathematical optimisation to reduce emissions and maximise pooled profits. • Plants receive an average of 12% higher profits when sharing their carbon permits. [ABSTRACT FROM AUTHOR]

In the current work, the feasibility of a novel heat and power cogeneration system comprising a biomass gasifier, a supercritical carbon dioxide cycle, a gas turbine cycle, a Stirling engine, and a domestic water heater in a well-organized design is investigated. The whole system's performance has been appraised, overlooking the role of the Stirling engine. The biomass fuels employed in the gasification process are municipal solid waste (MSW), paper, paddy husk, and wood. Subsequently, the energy, exergy, exergoeconomic, and environmental (4E) investigations are applied to conduct a comparative study and designate the best biomass. Consequently, the MSW was recognized as efficient biomass fuel, and the comprehensive parametric study and multi-criteria optimization for the whole system were implemented utilizing this fuel. The optimization process has been performed using the MOGWO algorithm and the LINMAP decision-making approach. The results revealed that the evaluated variables are more sensitive to vary the gas turbine inlet temperature and Stirling engine features than the other parameters. Also, for the MSW, the optimum exergy efficiency and total coat rate of the setup are found to be 46.48% and 401.4 $/h, respectively. • A novel cogeneration system fueled by different biomasses is suggested. • The system's performance is analyzed, overlooking the role of the Stirling engine. • The energy, exergy, exergoeconomic, and environmental analyses are performed. • The optimization process is conducted using the grey wolf optimization algorithm. • The optimum exergy efficiency and cost rate are found to be 46.48% and 401.4 $/h. [ABSTRACT FROM AUTHOR]

The carbon cycle of forest ecosystems plays an important role in cutting down global environmental pressure, reducing greenhouse effects, and assimilating carbon dioxide. Model simulation has developed rapidly and become an irreplaceable method in researching carbon cycle mechanisms and estimating carbon fluxes of forest ecosystems. So far, little research has systematically reviewed the progresses in forest carbon cycle models. A review of forest carbon cycle models on spatiotemporal scales will be timely and valuable. In this paper, the forest carbon cycle models on spatiotemporal scales were reviewed, and the advantages and disadvantages of forest carbon cycle models at different spatiotemporal scales were compared. The existing problems of forest carbon cycle models were analysed. Proposals on the prospects of forest carbon cycle models in the future were presented. This review can provide new ideas and a comprehensive understanding on the assessment method development of current forest carbon cycle. [ABSTRACT FROM AUTHOR]

In response to climate change, carbon emission reduction has become an important goal worldwide. Forests are the largest carbon pool in terrestrial ecosystems with a high carbon density and a fast carbon accumulation rate, and play a key role in the global carbon cycle. In this paper, the dynamic change and influence factors of forest carbon sequestration efficiency was analysis using the Data Envelopment Analysis Malmquist method in province level of China. The results showed that Heilongjiang, Yunnan, Tibet, Sichuan, and Inner Mongolia had the highest carbon sequestration, while northern China, eastern China, and southwestern China had the highest carbon sequestration efficiency. Furthermore, the factors of gross domestic product (GDP) per capita, urbanization, and the length of the highway network had significant positive impacts on the carbon sequestration efficiencies, while the total imports and exports had a significant negative impact. Ecological afforestation, temperature, GDP per capita, urbanization, population, and total imports and exports had spillover effects. It is recommended that the northeastern, central-southern, and southwestern regions with high carbon sequestration efficiencies should be used as the main areas to enhance carbon sinks in the future, and the areas with low efficiencies should respect the laws of nature more. Provinces should take into account the characteristics of the science and technology needs of forest areas and should provide forestry technology extension services. The results of this study are of great significance to improving the efficiency of financial investments, forest quality, and carbon sinks. • Forest transition has shifted from increased forest land cover to increased forest ecosystem services; •Factors affecting the level of forest carbon sequestration productive efficiency are Natural conditions--bio-physical; urbanization rate; economic and demographic conditions; degree of openness •Northeast, Central South, and Southwest of China with high carbon sequestration efficiency can be used as the main areas; •This result would be conducive to carry out the ecological construction of suitable forests. [ABSTRACT FROM AUTHOR]

Abstract: Alcohol fuel is generally presented as a sustainable fuel in comparison with other fossil fuel due to lower emissions during production and combustion steps as well as due to its (assumed) closed carbon cycle. However, assessing the Brazilian traditional alcohol production cycle, many social and environmental impacts may still be indicated: burning, pesticides, biodiversity, labor exploration, high water consumption, erosion and others. Based on the strategy of an agro-industrial networking and symbiosis, a project was designed to optimize the system by means of polygeneration and total integration of production steps. The case presented in this paper is the project for a social and ecological agro-industry model, named GERIPA (Geração de Energia Renovável Integrada à Produção de Alimentos), which produces renewable fuel, electricity and organic food. Besides the technical project, an economic evaluation is also presented, resulting into a five year pay back time. In addition, environmental and social aspects were evaluated by means the Emergy Synthesis methodology (Odum, 1996), which assesses the value of all inputs through an estimate of the environmental work directly and indirectly required for their production and sustainable supply. The emergy-based comparison of GERIPA system and a traditional system in Brazil indicates better performance of GERIPA, with an eMergy Sustainability Index of 1.26, much higher than for a traditional system, 0.22. The project is presently under discussion with investors and Government and, if approved, will be carried out in marginal and presently unused land. In addition to providing an environmentally friendly process for food and energy production, the project would generate new jobs opportunities for Brazilian rural workers presently unemployed. [Copyright &y& Elsevier]

This paper investigates the potential indicators influencing CO 2 emission in Shanghai during 1995–2017 by a combined method of logarithmic mean Divisia index method (LMDI) and Granger causality test for the purpose of strengthening the sustainability in dynamic perspectives. Firstly, we quantify the contributions of potentially influential factors of CO 2 emission, and then a further analysis of different relationships between CO 2 emission and the mainly potential factors are identified. The results show that the motor vehicle amount, the disposable personal income, the carbon intensity, and the urbanization rate are the top four driving forces of CO 2 emission. The result of Granger causality test indicates that the motor vehicle amount has a bidirectional Granger causality relationship with CO 2 emission in different lags, while the urbanization rate, per motor vehicle secondary industry, per secondary industry population, per residents' income GDP support coefficient and the carbon intensity have a one-way Granger causality relationship with CO 2 emission. Interestingly, it is found that the policy implementation or main events are closely related to the influential factors of CO 2 emission. Thus, policy makers should not only continue to implement current related policies of reducing CO 2 emission but also pay attention to the effect of great events of urban development. • The motor vehicle amount effect is the top driving forces of CO 2 emission. • CO 2 emission may have a closed relationship with urban policy. • Causality between factors by Granger causality test were investigated. • Motor vehicle amount has bidirectional Granger causality relationships with CO 2 emission. • Policy implication of carbon emission reduction were discussed. [ABSTRACT FROM AUTHOR]

Litter decomposition is a vital component of carbon and nutrients cycling and energy flow within terrestrial ecosystems. Understanding the litter decomposition rate with a temperature change of 1 °C (k DD , degree days−1) is critical for quantifying the climate-carbon, nutrients, and energy cycle feedback and predicting the response of ecosystems to climate change. However, the spatial pattern of k DD is uncertain, given differences in litter quality and soil property responses to temperature. Therefore, our goal was to explore the spatial patterns and driving factors of the k DD with a synthesized dataset, which included 1370 individual studies from 253 publications and accumulated daily temperature of each site from 389 meteorological stations. The dataset covered forest, grassland, and cropland ecosystems. The k DD significantly decreased with increasing latitude and varied with climate variables, litter quality, soil properties, and experimental duration under different ecosystems. The averaged k DD in the forest, grassland, and cropland ecosystems were 1.30, 2.23, and 3.35 × 10−4 degree days−1, respectively. The k DD markedly decreased with the increase of experimental years. Climate variables [mean annual temperature (MAT) and precipitation (MAP)] accounted for 36.8% of the total variance in the k DD , followed by soil properties (e.g., soil sand content and pH; 28.1%); experimental duration (23.0%); and litter properties (e.g., nitrogen and lignin; 12.1%). MAT and MAP had substantially indirect effects on k DD via regulating soil and litter properties. Lignin directly and negatively affected k DD. Higher correlations between k DD and litter properties were maintained if the effects of climate, soil properties, and experimental duration were removed. Overall, our findings highlight that intrinsic (litter properties) and extrinsic (climatic and soil properties) variables directly and indirectly regulated the k DD at a regional scale, respectively, providing a framework for optimizing the ecosystem process model to global warming scenarios. Meantime, these results clarify the crucial role of environmental variables in regulating the k DD , potentially affecting the terrestrial carbon, nutrients, and energy-climate feedback. Image 1 • The highlights of the paper are as follows: • Litter decomposition rate significantly decreased with increasing latitude and experimental time. • A network of climate, soil properties, and litter properties determined litter decomposition rate. • Intrinsic and extrinsic variables directly and indirectly regulated litter decomposition rate. [ABSTRACT FROM AUTHOR]

This study presents a comparison of the life cycle carbon emission (LCCO 2) and embodied energy calculation between two kinds of bricks, sun-dried and fired clay, as means of evaluating the energy and climate impact of each brick type and the economics of production. Focus is paid to the differences across the whole production chain between sun-dried clay bricks, which represent the traditional norm, and fired clay bricks, which are the most widely-used walling materials in conventional buildings. A case study was carried out in Dakhla Oasis in the Western Desert of Egypt. The results of this study show that if sun-dried bricks are used instead of fired bricks, a reduction of up to 5907 kg CO₂e (in CO₂ emissions) and 5305 MJ of embodied energy for every1000 bricks produced could be achieved. The paper concludes by offering alternative scenarios for brick-making and suggestions for improving sun-dried brick production. The methodology used in this study contributes to the development of an investigative-comparative way to assess choices between building materials. It also intends to help inform local homeowners and building practitioners not only in Egypt, but also globally, about resource depletion, energy consumption, and harmful emissions from fired industrial bricks as a common building construction material. • Sun dried clay bricks are a nearly zero carbon building material with low embodied energy. • For every 1000 sun-dried bricks, a reduction in CO₂ by 5907 kg CO2e and 5305 MJ EE is achieved. • Social and cultural norms can affect the choice of different building materials. [ABSTRACT FROM AUTHOR]

Due to global warming and energy conservation, the importance of forests should be seriously considered. Forest could not only produce bioenergy by harvest to substitute fossil fuels, but also sequestrate carbon dioxide from the air without harvest. How to measure the trade-off between forests as bioenergy production and carbon sinks is the aim of this paper. The forest management for the trade-offs is modelled theoretically based on two perspectives of carbon reductions and benefits. The magnitude of trade-offs is calculated considering carbon reduction, ecological benefit, and economic benefit by empirical analysis based on the forestry database of 180 countries. The empirical results reveal that the magnitude of trade-offs is lowest in Iran both between carbon sinks and carbon flow from the perspective of carbon reductions and that between economic benefit and ecological benefit based on forest income. It implied the coordinated development of wood fuel and carbon sinks in Iran's forest management. Meanwhile, the magnitude of trade-offs is highest in Ecuador between carbon sinks and carbon flow, and it is highest in Tongo between economic benefit and ecological benefit. It showed that forest management should be improved. Furthermore, energy and environment policy implications could be proposed based on forest management. Effective forest management should be considered to help fully realize energy conservation and environment protection. Image 1 • The trade-off is explored which forest is as bioenergy production or carbon sink. • Trade-offs are modelled theoretically based on carbon reductions and benefits. • The magnitudes of trade-offs in 180 countries are compared. • Energy and environment policy implications could be proposed by forest management. [ABSTRACT FROM AUTHOR]