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China is facing challenges to tackle the threat of climate change while reducing social inequality. Poverty eradication requires improvement in the living conditions of low-income households, which leads in turn to higher carbon footprints and may undermine the efforts of climate change mitigation. Previous studies have assessed the climate impacts of poverty eradication, but few have quantified how the additional carbon emissions of poverty eradication are shared at the subnational level in China and the impact on China's climate targets. We investigated the recent trend of carbon footprint inequality in China's provinces and estimated the climate burden of different poverty reduction schemes, measured by increased carbon emissions. The results indicate that poverty eradication will not impede the achievement of national climate targets, with an average annual household carbon footprint increase of 0.1%–1.2%. However, the carbon emissions growth in less developed provinces can be 4.0%, five times that in wealthy regions. Less developed regions suffer a greater climate burden because of poverty eradication, which may offset carbon reduction efforts. Therefore, interregional collaboration is needed to coordinate inequality reduction with investments in low-carbon trajectories in all provinces. [ABSTRACT FROM AUTHOR]

Ethylene is one of the most important products in the emissions-intensive petrochemical industry. Decarbonizing the ethylene industry is thus important for achieving global carbon neutrality. This study is the first to explore future long-term zero-emissions production pathways for the ethylene industry in China, the world's biggest ethylene producer. An optimization model was built in the context of China's carbon neutrality target of 2060. Four scenarios were developed where the policy ambitions for climate mitigation and for plastic management including waste were varied. Based on this, authors assessed the cumulative total emissions, technology options, future geographical location of ethylene production, and policy challenges associated with each scenario. This is also the first time that scope 3 emissions from waste incineration are included, motivated by the short lifetime of most ethylene products. Results show the cumulative CO 2 emissions for the scenarios differ considerably, ranging from 4.3 to 7.8 Gt, even if carbon neutrality by 2060 is achieved in all scenarios. The results suggest that ambitious plastic focused policies can result in lower costs and less cumulative emissions compared to ambitious climate focused policies. The results demonstrate the importance of adopting CCS for waste incineration. This reduces cumulative CO 2 emissions by up to 2 Gt. However, reduced overall demand and increased recycling rates should be priority options due to CCS challenges. Results suggest Chinese ethylene industry should adopt a mixed portfolio of production technologies, where the share of emission-intensive coal-based methanol-to-olefins is limited. These findings on decarbonization pathways can contribute to achieving the Paris agreement. [Display omitted] • Ambitious plastic policies lead to 1.3 Gt less cumulative CO 2 than climate policies. • Cumulative CO 2 until 2060 can be reduced by 3.5 Gt compared to reference scenario. • Adopting CCS in incineration can reduce cumulative CO 2 emissions by 2 Gt. • Ethylene industry should adopt a mixed production portfolio due to uncertainties. • Coal-based MTO with CCS does not appear to be a cost-competitive option. [ABSTRACT FROM AUTHOR]

Carbon neutrality strategies have a significant role in climate mitigation efforts. As global concerns regarding climate change continue to increase, achieving carbon neutrality has emerged as a paramount objective for reducing greenhouse gas emissions and limiting the adverse impacts of anthropogenic activities on the environment. This research investigates a wide range of scholarly works to conduct an in-depth analysis and synthesis of the relevant information about carbon neutrality strategies. The review introduces carbon neutrality principles and terminologies, highlighting their importance in climate mitigation. It then proceeds to explore the wide range of strategies employed across different sectors and industries, investigating their effectiveness, scalability, and potential challenges. A multidimensional analysis contrasts the United States Nationally Determined Contributions pathway 2023, China's Nationally Determined contributions 2023, and the EU Directive 2023/2413, assessing their economic, environmental, political, and social impacts. The study evaluates strategies' effectiveness, scalability, and innovation for transitioning to a sustainable, low-carbon future. It fills a gap by analyzing global approaches across the US, China, and the EU, which account for about 50% of the world's total GHG emissions. It evaluates the novel application of diverse strategies, from renewable energy transitions to innovative policy measures, highlighting their potential to mitigate climate change effectively. By providing a multidimensional analysis of these strategies' impacts, the research not only enhances understanding of effective carbon neutrality tactics but also underscores the importance of international cooperation in realizing a sustainable, low-carbon future. • Identifies and analyzes carbon neutrality strategies, emphasizing the need for diverse US, Chinese, and EU approaches. • Evaluate renewable energy, carbon capture, and policy tools for carbon reduction effectiveness, scalability, and innovation. • Highlights the study's novelty in synthesizing current knowledge on carbon neutrality, addressing a significant research gap. • Concludes with strategic ideas for international collaboration and policy development for low-carbon futures. [ABSTRACT FROM AUTHOR]

[Display omitted] • Contribution variations of various policies to PM 2.5 deaths are quantified by period and region. • Carbon and pollution controls can enable 79% to reside in low PM 2.5 areas by 2060. • Population aging could double PM 2.5 deaths by 2060 if other factors remain constant. • A joint effort for carbon and pollution could prevent 2.15 million PM 2.5 deaths by 2060. • Pollution controls can greatly reduce PM 2.5 before 2030, but climate policy becomes crucial after. To confront the challenges posed by air pollution and climate change, China has undertaken significant initiatives to develop strategies that address both issues concurrently. However, the health benefits of these initiatives have not been clearly articulated. In this study, the dynamic changes in health impacts under air pollution and carbon reduction actions in China are evaluated by employing the latest concentration–response models and projected PM 2.5 concentrations under future scenarios. From 2020 to 2060, the enforcement of clean air and climate mitigation policies is expected to increase the percentage of the population living with PM 2.5 concentrations meeting the 10 μg/m3 standard by 79 %. Without the implementation of relevant mitigation measures, PM 2.5 -associated deaths are projected to double due to an aging population. In comparison to the 2060 reference scenario, the joint implementation of clean air and carbon neutrality measures is expected to reduce nationwide PM 2.5 -associated mortality by 62 %, equivalent to 2.15 (95 % CI: 1.80–2.48) million deaths. Stringent pollution controls are crucial for reducing PM 2.5 -associated deaths before 2030, after which carbon neutrality actions become increasingly significant from 2030 to 2060. The challenges of mitigating future PM 2.5 -associated deaths vary greatly across regions, showing a critical response to pollution control and carbon reduction. The research proves the effectiveness of China's future air pollution control and carbon reduction policies in mitigating PM 2.5 -associated deaths. [ABSTRACT FROM AUTHOR]

• Implementation costs are a more relevant constraint to afforestation than opportunity costs. • Financial incentives for afforestation are constrained by market access and market prices. • Carbon-neutral and food multi-oriented land policies need further exploration. • Collaboration among global carbon markets can enhance CO 2 removal efficiency. Afforestation is a promising nature-based climate solution for mitigating climate change, but it is subject to a complex web of biophysical, cost-benefit, market, and policy processes. Although its biophysical feasibility has been established, the cost, market, and policy constraints that affect climate change mitigation through afforestation are still unclear. Here, we estimate such cost, market, and policy constraints on the basis of biophysical feasibility. Our findings reveal that implementation costs are a more relevant constraint than opportunity costs on mitigating climate change through afforestation. The China Certified Emission Reduction market currently provides only a 0.308 % incentive for climate change mitigation through afforestation, due to market access constraints. The current market prices of China Certified Emission Reduction, China Carbon Emissions Trading Exchange, and Nature Based Carbon Offset in Voluntary Carbon Market constrain 88.15 %, 87.95 %, and 85.75 % of CO 2 removal actions through afforestation, compared to the carbon price scenario (US$62.97 tCO 2 -1) of the EU Emissions Trading System. Moreover, land policy under the scenarios of prohibiting conversion of cultivated land to forest and forest restoration in degraded areas exhibit 8.87–29.59 % and 65.16–74.10 % constraints, respectively, on mitigating climate change through afforestation compared to land-use freedom conversion scenarios from 2020 to 2060. Thus, enhancing the incentive price of CO 2 removal, addressing the market access barrier, strengthening cooperation between global carbon markets, and exploring carbon–neutral and food multi-oriented land policies can be valuable sources of mitigation efforts over the next 40 years. [ABSTRACT FROM AUTHOR]

• The 57.00% of the Yangtze River Economic Belt area exhibited a significant increase in annual NPP. • The response of NPP on climate factors was nonlinear, with greater sensitivity to temperature. • The impact of topographic factors on NPP changes had a threshold effect. Net primary productivity (NPP) of terrestrial ecosystems serves as a crucial carbon sink, playing a significant role in mitigating climate change. This study, focusing on the Yangtze River Economic Belt (YREB), a key area for both economic development and ecological conservation in China, evaluates the temporal and spatial changes in regional NPP and its responses to climatic factors against the backdrop of global change. Utilizing long-term NPP and meteorological grid data from 1981 to 2017, we analyzed the annual change patterns of NPP and its linear and nonlinear responses to climatic factors using copula functions. Our findings indicate that 57.00 % of the YREB has experienced a significant increase in NPP, with the most substantial decreases observed in Shanghai and its surrounding areas (P < 0.05). Temperature emerged as the primary climatic driver, positively correlating with NPP changes in over half of the study area (P < 0.05). Moreover, the nonlinear response of NPP to temperature and precipitation underscores the complex interactions between these factors, revealing a sensitivity to temperature variations that surpasses that to precipitation. The study also highlights the influence of solar radiation and topographic factors, with a significant positive correlation between NPP and solar radiation observed in 15.85 % of the area (P < 0.05). The practical significance of these findings lies in their implications for regional ecological management and climate resilience strategies. The positive correlation between temperature and NPP underscores the potential for targeted temperature management to optimize carbon sequestration across the YREB. Furthermore, the identified nonlinear responses and the role of solar radiation and topography in influencing NPP offer valuable insights for the formulation of adaptive strategies that enhance ecosystem productivity and contribute to achieving carbon neutrality goals. By elucidating the dynamics of NPP in response to a range of environmental factors, this study provides a foundation for informed decision-making in ecological conservation and climate change mitigation efforts within the YREB and similar regions globally. [ABSTRACT FROM AUTHOR]

• A CGE model elaborately depicting six CCS technologies was developed. • Impacts of four CCS incentive scenarios on decarbonization pathways were simulated. • CCS can sequester 960 ∼ 1,604 MtCO 2 annually in China by 2060 with policy incentives. • CCS incentives can reduce China's future primary energy demand by 7.7 ∼ 17.4 %. • CCS incentives can increase GDP by 5.64 ∼ 6.59 % compared to no policy scenario. Carbon capture and storage (CCS) technology, considered as a pivotal tool in mitigating climate change within the fossil energy system, particularly in China, has experienced slower development than expected. The exploration of direct incentive policies to facilitate its growth remains relatively underdeveloped. This study developed a hybrid dynamic computable general equilibrium (CGE) model to simulate the substantial impacts of CCS incentive policies on China within the context of carbon neutrality target. Two potential incentive policies, carbon emission trading system (ETS) and 45Q tax credit, were simulated, with different sectoral coverage. The results indicate that CCS technologies can reduce carbon emissions by 960 ∼ 1,604 MtCO 2 annually by 2060 through the strategic implementation of these incentive policies. The 45Q tax credit demonstrates its effectiveness in promoting early-stage research and development (R&D) and demonstration of CCS, while the ETS policy facilitates the commercial development of CCS in the later stage of development. By 2060, the implementation of CCS incentive policies could potentially result in 7.7 ∼ 17.4 % reduction in China's primary energy consumption, 71.2 ∼ 82.7 % decrease in the carbon price of ETS and 5.64 ∼ 6.59 % increase in the GDP compared with the no-policy scenario. In addition, the sectoral output in various sectors and the welfare of urban and rural households also increase. This paper provides an important reference for the realization of China's carbon neutrality goal and the model framework can be applied to other countries. [ABSTRACT FROM AUTHOR]

The ever-increasing challenges related to water security and climate mitigation underscore the pressing need for forward-thinking systems planning tools to drive urban sustainability transitions. In this study, we propose a novel city-level multi-objective planning framework that explores the nexus between carbon trading and water management, with the aim of facilitating water-efficient urban industrial restructuring. The framework integrates cap-and-trade mechanisms into a two-layered optimization model, creating an integrated approach to optimizing carbon emissions and generating economic opportunities for improving water efficiency. To illustrate the potential application of this framework, we conducted a case study focusing on Dongguan City, a water-stressed industrial metropolis in southern China. The results illustrate potential synergies between water planning strategies and carbon trading schemes, which could be harnessed to enable targeted reductions in water usage and carbon emissions. Furthermore, our findings identify the textile, apparel, and paper products manufacturing industries as primary candidates for strategic production scale reduction, emphasizing the importance of sustained support for the development of the computer and electronic manufacturing sector as a catalyst for urban sustainability transitions. By pioneering this new nexus-based perspective, our study offers valuable insights into long-term strategic planning for a low-carbon and resource-efficient urban economy. • Synergizing carbon trading and water management within a novel integrated planning framework. • Implementing resource-efficiency-driven optimization for water- and carbon-intensive manufacturing sectors. • Gaining insights into the specific roles of key manufacturing sectors in water management and carbon trading. • Introducing carbon trading systems may help in promoting water-efficient industrial restructuring. [Display omitted] [ABSTRACT FROM AUTHOR]

• The Carbon sink capacity of a typical ecotypic county was precisely estimated. • STARFM was employed to estimate interannual NEP at county scale. • The NEP dataset at a 30 m grid scale from 2000 to 2020 was generated. • Spatio-temporal dynamics of NEP in ecotype county were grasped. Net ecosystem productivity (NEP) serves as a pivotal metric for quantitatively elucidating the carbon sink function of terrestrial ecosystems. As a prototype county for the development of an ecological civilization in China, the quantitative estimation of the ecotypic county's ecosystem carbon sink capacity holds immense significance in comprehending the carbon cycle and facilitating the sustainable advancement of regional ecosystems. This study undertook the estimation of NEP in Wuning County from 2000 to 2020, employing a fusion of multi-source remote sensing data, the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM), the improved Carnegie-Ames-Stanford Approach model, and the soil respiration model. Furthermore, we delved into the differences in NEP across various types of land cover. In addition, we employed the Theil-Sen Median trend analysis and Mann-Kendall test to discern the spatio-temporal trends of NEP. The findings indicated the following: (1) The downscaled NDVI generated by STARFM exhibited a remarkable consistency with Landsat NDVI overall (R 2 > 0.95, P < 0.01, 0 < RMSE < 0.1). (2) The gross NEP from 2000 to 2020 in the study area ranged from 542.78 to 720 Gg C, with a multi-year average NEP of 183.84 g C m−2 yr−1. The simulated NEP demonstrated higher accuracy when compared to the measured data (R 2 = 0.79, P < 0.01). (3) The NEP exhibited a spatial pattern characterized by lower values in the central area and higher values in the north and south. Approximately 89.60 % of the total area demonstrated an increase in NEP, with woodland acting as the primary contributor, while 4.50 % of the total area displayed a decreasing trend, predominantly due to the expansion of built-up land. (4) Notable variations in NEP existed among different types of land cover. In terms of vegetation types, the annual average NEP ranked as follows: woodland > grassland > cropland. The application of STARFM has provided valuable insights into the methodology for precise delineation of spatio-temporal dynamics of NEP at the county scale. The outcomes of this study have furnished support for implementing climate change mitigation strategies in ecologically-oriented counties and the bottom-up promotion of China's carbon peaking and carbon neutrality goals. [ABSTRACT FROM AUTHOR]

• Forest residues, a renewable energy, have great potential to substitute fossil fuels to reduce enormous pressures of energy shortages in mitigating climate change. However, it is a challenge to quantify forest residues at a fine spatial scale due to large spatial variations of forest species and lacking of suitable research methods. In addition, the natural decomposition of forest residue is often ignored in future greenhouse emission prediction, • We estimated the total forest residues in China reached 152.13 million t in 2018. The forest residues had faster decomposition rate (annual natural decomposition value of carbon from forest residues) in the first ten years, and then gradually decreased. In the first 14 years, the half forest residues was decomposed. The national contribution to climate change (CCC) from forest residues over one-hundred-year reached 49.27 million t CO 2 eq. The peak values of the provincial annual CCC were reached within 15 years and we found that the highest annual CCC occurred in the second year since the natural decomposition. • There are two major contents. First, a method is put forward to downscale the reserve of forest residue to county-level administrative unit. Prior to this, the resolution of the estimations was generally at provincial level. Obviously, more refined data was conducive to encourage the utilization of biomass by providing references for policymakers and investors. Second, a new index was implemented to assess the contribution of the natural decomposition of unused forest residues to climate change. • We estimated that CCC caused by their natural decomposition reaches 4.927 million t CO 2 eq, which was 0.96%−6.5% of other carbon emission sources (i.e. staple crops, inland water) in China. From a global perspective, such carbon emission was 0.015% of global wetland carbon emissions and 1.59% of global peat land carbon emissions. • Our study provides new data to support future climate mitigation, reducing the significant uncertainty in related research, and will make researchers, policymakers, and investors recognize the great potential of forest residues as an energy source and the significant contribution of their natural decomposition to climate change and promote carbon neutrality transition. Under the energy shortage and emerging climate change caused by fossil energy, forest residues were encouraged to be used as an energy resource. However, it is a challenge to quantify the forest residue at the fine spatial scale due to the available data and suitable research methods. We aimed to quantify the available forest residues in China at the county scale and clarify their potential contribution to climate change (CCC). The availability of forest residues reached 152.13 million t in 2018 in China. The CCC accumulated by natural decomposition of forest residues over one-hundred-year had reached 49.27 million tCO 2 eq. The peak values of provincial annual CCC were reached in the first 3 years in the southern region. The top four counties of CCC were all from Yunnan Province. The energy utilization of forest residues is of great significance to the management of forest resources. [Display omitted] [ABSTRACT FROM AUTHOR]

Under the background of "carbon peak" and "carbon neutrality", China's cities are at the heart of climate change mitigation. To fulfill the commitments, the potential drivers of China's low-carbon economy at the city level should be explored. Thus, this study estimated the quality of low-carbon economy from the perspectives of carbon emissions and sequestration. Subsequently, spatial econometric approach was adopted to analyze the direct and spatial spillover effects of drivers on low-carbon economy. Moreover, to explore more potential variables, this study combined machine learning algorithms with different weight matrices to assess the importance scores of neighbouring cities' potential variables. The results show that (1) GDP per capita, emissions reduction technological progress, terrestrial vegetation's net primary productivity and the ratio of forest land cover improved cities' low-carbon economy; (2) land urbanization reduced nearby cities' low-carbon economy (especially those with high human footprint index at the inter-city border), which was caused by its negative spatial spillover effects on forest net primary production; (3) based on importance analysis, this study found that the characteristics of different sectors (e.g., the ratio of labor to fixed capital stocks, employment and fixed asset investment expenditure) also significantly influenced nearby cities' low-carbon economy. • China's city-level quality of low-carbon economy (reo) was estimated based on carbon intensity and sequestration. • The importance of 72 variables' spatial spillover effects were ranked based on machine learning algorithms. • Terrestrial vegetation's net primary productivity and the ratio of forest land cover greatly improved the reo. • The spatial spillover effect of land urbanization was negative in nearby cities. [ABSTRACT FROM AUTHOR]

Cities are the major contributors to global carbon dioxide emissions; however, the carbon transfers embodied in cities' domestic and foreign trade have not been fully discussed. As carbon emissions from different domestic and foreign trade partners have not been distinguished, and since China's four municipalities (Beijing, Tianjin, Shanghai and Chongqing) carry an increasingly significant responsibility for carbon reduction in China, a multi-scale and multi-regional carbon emission assessment is applied to identify their emission transfers to and from 26 domestic provinces and 184 foreign economies. The results show that the intensities of the four municipalities are mainly above the international standard (0.14 kg/CNY) but beneath the Chinese average (0.24 kg/CNY). 71.72%, 55.35%, 65.34% and 33.65% of their emissions are imported from other regions. Generally, the four municipalities are net recipients of domestic carbon transfers and suppliers of foreign carbon transfers. Carbon transfers from Hebei to Beijing and Tianjin, Zhejiang to Shanghai, and Sichuan to Chongqing as well as from Beijing and Tianjin to Japan and South Korea and from Shanghai and Chongqing to the United States and Germany are identified in domestic and foreign supply chains. The multi-scale and multi-regional simulation and assessment in this work allows us to identify the carbon emissions not only within a city's boundaries but also via inter- and intra-national trade, providing a solid foundation for the carbon emission assessments of Chinese mega cities from an embodied perspective. [ABSTRACT FROM AUTHOR]

While feeding 20% of global population, China's agriculture is a large greenhouse gas (GHG) emitter, posing a major challenge to the country's carbon neutrality target. However, the pathways of agriculture towards carbon neutrality remain unclear. To address this knowledge gap, we conduct a comprehensive life-cycle assessment and show that valorization of sustainable biomass wastes (crop residues, forest residues, livestock manure, food waste, and sewage sludge) into biochar can contribute importantly towards agricultural carbon neutrality in China. The maximum potential of biochar production from these waste resources in 2018 is 145 Mt yr−1 with a corresponding GHG mitigation potential of 455.7 (405.5–572.4) Mt CO 2 -eq yr−1. This can fully offset the total CH 4 and N 2 O emissions from China's croplands (∼400 Mt CO 2 -eq yr−1), which are difficult to be entirely eliminated due to rice paddy irrigation and intensive use of fertilizers. Distribution of biomass waste varies across regions, and at the national level , crop residues (48.8%) and livestock manure (25.4%) and food waste (15.6%) are the main sources of biochar feedstocks and should be prioritized in biochar development. Forest residues have a marginal contribution due to competing uses from other sectors, and sewage sludge derived biochar is a net source of GHG emissions due to the large energy consumption required for sludge drying. The total GHG mitigation potential of biochar is greatly affected by pyrolysis temperature and the highest mitigation effect is observed under 300–500 °C. These results underscore the benefit of sustainable biochar production to agricultural carbon neutrality, and to maximize the climate benefit requires differential policies and pyrolysis technologies tailored to regional availability of biomass resources. • The GHG mitigation potential of sustainable biochar in China was analyzed. • The maximum mitigation potential can offset all CH 4 and N 2 O emission from croplands. • Biochar GHG mitigation potential is affected significantly by pyrolysis temperature. • Sustainable biochar can contribute toward agricultural carbon neutrality. [ABSTRACT FROM AUTHOR]

In an effort to contribute to climate change mitigation, China has committed to achieving its peak carbon by 2030 and carbon neutrality by 2060. However, reaching these goals will require a massive reduction in carbon emissions. The humans have to consume food to meet their survival needs. Furthermore, the society's demand for food is consistent with the development level of agricultural structures. At present, reducing environmental costs associated with food to adjust the agricultural structure has not received sufficient scientific attention. Because of this, the present study combines food consumption, climate change, and agricultural structure to design future scenarios based on the widely used SSP storyline. Moreover, in order for China to reach its carbon peak in 2030, this study applies a life-cycle approach to uncover the potential carbon reduction of Chinese residents under different dietary structures. From a demand perspective, this study puts forward recommendations for dietary restructuring and guides the direction of future agricultural restructuring in China. It also shows that a diet structure that replaces red meat with plant foods such as vegetables and fruits will have a more significant carbon reduction potential. The traditional agricultural structure consumes a large amount of food and produces a significant amount of greenhouse gases. Reducing meat and high-fat foods consumption may help reduce GHG emissions produced by food consumption. In addition, reducing the proportion of food used for feeding in the agricultural structure will also help achieve peak carbon targets. The shift in diet structure will advance China's agricultural structure and promote green agriculture development. • Food consumption and related carbon emissions within the 2030 scenario will continue to increase, with the highest share of rice consumption. • The carbon emissions of food consumption in the environmentally sustainable scenario will decrease. • Readjusting toward a more balanced diet could significantly contribute to the carbon peak goal. • A shift in dietary structure will promote agricultural restructuring. [ABSTRACT FROM AUTHOR]

Urban parks are considered as an effective, sustainable, and affordable heat mitigation strategy. At present, there is a lack of understanding of the carbon saving potential of urban parks in the context of urban warming. Here we provide a simple approach to estimate the potential carbon savings due to heat mitigation based on analysis of 1510 parks in 26 major urban areas of the years 2017–2021 within the Yangtze River Economic Belt (YREB), China's largest sustainability experiment. On average, an urban park with 26.9 ± 1.5 ha in the YREB could avoid 23.7 ± 1.6 t CO 2 (1.08 ± 0.03 t CO 2 /ha) in emissions due to heat mitigation per summer day. Considered altogether, the 1510 urban parks can offset 5.37% of the daily fossil fuel emissions in the YREB. To boost carbon saving efficiency, lush vegetation should be first considered and the coupled green and blue infrastructures are always advocated. The total parks carbon saving of cities gradually improved along the Yangtze River from west to east, among which Shanghai city (in the east of the YREB) is with the largest amount (4341 t CO 2). The strategies using exquisite landscape design for improving carbon saving may differ across different climate zones. These findings can inform decision-making for urban sustainable development and climate change mitigation, which may benefit China's movement toward carbon neutrality. [ABSTRACT FROM AUTHOR]

Carbon neutrality objectives affect meteorology and ozone (O 3) concentration in China, both of which would influence crop yields, thus food security. However, the joint impact of these two factors on crop yields in China is not clear. In this study, we investigated future trends in China's maize, rice, soybean, and wheat yields under a carbon-neutral scenario considering both regional emission reduction and global climate change in 2060. By combining a process-based crop model (Agricultural Production Systems sIMulator, APSIM) with O 3 exposure equations, the impacts of regional emission reduction and global climate change were studied. The results suggest that regional emission reduction dominated the increase in yield by reducing the O 3 concentration, whereas global climate change led to yield loss mainly through meteorological factors. The national yield decreases for the four crops ranged from 1.0% to 38.0% owing to meteorological factors, while O 3 reduction resulted in additional yield increases ranging from 2.8% to 7.0%. The combined effect of carbon neutrality, which included both meteorological factors and O 3 concentration, resulted in changes to the yields of maize, rice, soybean, and wheat of +4.3%, -7.3%, -24.0%, and -31.7%, respectively. It seems that crop production loss caused by meteorological factors in 2060 would be mitigated by the O 3 reduction. Given the advantages of declining O 3 concentration, regional emission reduction would likely benefit crop growth. However, global climate change may offset the benefits and threaten food production in China. Therefore, more strict emission reduction policies and global climate change mitigation actions are necessary to ensure food security in China. [Display omitted] • Low carbon emissions would lead to increased crop yields in China. • Crop yield loss is mitigated owing to ozone decreases induced by emission reduction. • Global climate change would cause yield loss mainly through meteorological factors. [ABSTRACT FROM AUTHOR]

Carbon capture, utilization, and storage (CCUS) is a crucial technology for global climate mitigation. To implement large-scale CCUS, decisions about where and how to build a CO 2 transportation network are urgently required. However, previous studies are limited in proposing the economical transportation network for CCUS that considered comprehensive risks from socio-economic, geographical and geological factors. Here, we develop a pipeline layout planning model to investigate the cost-effective and reliable transportation network for CCUS. Results show that to meet the annual CO 2 emission reduction target of 654 million tons for CCUS in the coal-fired power sector under China's carbon neutral goal, pipelines with a total length of 17,589 km need to be constructed. The emission sources can be transported in pipelines with an average radius of 58 km, and with diameters of 8, 12, and 16 inches. Northeast, north, and northwest China are the main areas suitable for pipeline construction. • Northeast, North, and Northwest in China are vital areas for capture, transport, and storage. • Five large-scale pipeline network groups can be constructed in China. • Pipeline construction is greatly affected by a variety of practical factors. [ABSTRACT FROM AUTHOR]

• An interval-parameter bi-level programming (IBP) method is proposed. • IBP can tackle conflicts between two-level decision makers under uncertainty. • An IBP_CES model is developed for planning China's energy system in 2021–2050. • The annual CO 2 emission would reduce up to 11.0% by 2050 compared with 2020 level. • Results show that IBP_CES compromises mitigation goals and economic decisions. To reach the goal of carbon-neutral society, synergistic approaches based on mathematical models that are capable of planning energy system associated with complex uncertainty and hierarchical structure are desired. In this study, an interval-parameter bi-level programming (IBP) method that is effective for solving hierarchical decision-making problems with conflict objectives and uncertainty is developed. Then, an IBP based China's energy system model (abbreviated as IBP_CES) is formulated for mainland China during 2021–2050, where the higher-level objective of minimizing carbon dioxide (CO 2) emission is given priority, following by the lower-level objective of minimizing system cost. Results from IBP_CES show that, although China's energy supply would still rely heavily on fossil fuels, the share of coal would decrease to 33.9% by 2050. Results also disclose that the national CO 2 emission would reach the peak value during 2026-2030 and then decline rapidly due to development of renewable energy and promotion of carbon-treatment technology which is beneficial for government to achieve carbon neutrality goals. In addition, compared to the traditional single-level model, CO 2 emission from IBP_CES can decrease by 5.9%, demonstrating that IBP_CES is more superior in energy system decarbonization. The findings can help decision makers to well understand the interactions and tradeoffs between climate mitigation and economic development, and provide effective information on clean, sustainable and deep-decarbonized development strategies. [ABSTRACT FROM AUTHOR]

• We construct a multi-model comparison framework by employing typical IAMs. • We examine how China will contribute to the global 1.5 °C climate target. • China could contribute nearly one-fifth of the global negative emissions by 2100. • The proportion of BECCS could dramatically increase to 29% under the 1.5 °C case. • Energy demand control may rely more on coordination between CCS and clean energy. Enhancing the warm-limiting targets to from below 2 °C to 1.5 °C is of great significance for climate change mitigation, during which the carbon capture and storage (CCS) of China is playing an important role. By framing a multi-model analysis to compare IAMs, this study aims to explore how China can contribute to the global 1.5 °C target, consistent with achieving its carbon neutrality goal. Our multi-model assessment shows that the enhanced targets will advance the reach time of China's carbon peak and neutrality. Under a relatively smooth emission path curve with CCS, China's carbon emissions will decrease sharply by the end of this century. It is estimated that China's negative carbon emissions will contribute nearly one-fifth of the global negative emissions in 2100, with its CCS-captured emissions accounting for 14%. In the energy system, fossil- and biomass-CCS will develop rapidly, with the proportion of biomass with CCS dramatically increasing to 29% and 17% under the 1.5 °C and 2 °C scenarios, respectively. There will be a relatively large gap between the capital and final use costs of CCS, which may weaken the technical advantage when competing with renewables during the life cycle. While the overall control of the energy consumption in the later period will rely more on the proportional adjustment and the coordination between biomass with CCS and clean energy. [ABSTRACT FROM AUTHOR]

[Display omitted] • TUEEC in 10 urban agglomerations in China are substantially different. • TUEEC within urban agglomeration have an impact on CO 2 emissions. • Ecological construction partially mitigated emissions growth. • Guarding against unsustainable development is vital to carbon neutral. Urban agglomerations are major generators of CO 2 emissions owing to human socioeconomic activities. Evaluating the trade-offs between urban expansion and ecological construction during rapid urbanization is a crucial step towards climate change mitigation and carbon neutrality. This study investigated the impacts of trade-offs between urban expansion and ecological construction on CO 2 emissions using multi-source data and spatial and statistical analysis. Ten urban agglomerations in China, with various development levels, were selected as study areas. The results indicated that (1) urban development in the 10 urban agglomerations expanded by 90%–288.9%, while ecological land changed by −28.1–2.3%. (2) CO 2 emissions grew by 154.2–291.2% in urban agglomerations, and the south and east of China emitted more CO 2. The high-value clusters of CO 2 inside of all urban agglomerations expanded outward from cities. (3) Urban expansion increased emissions, while ecological construction partially mitigated emissions growth. Moreover, ecological development within cities helps to reduce excessive urban emissions and should be given more attention. (4) It is as important to guard against unsustainable development as it is to reduce existing high emissions. Low-carbon development paths must continue to be supported in western China. On the basis of the results, we identify important implications for meeting China's target of carbon neutrality. These contribute to an understanding of future development modes for urban agglomerations and reveal the impact of trade-offs of land use on CO 2 emissions. [ABSTRACT FROM AUTHOR]

Building sector plays a significant role in China's ambitous climate targets to peak carbon emissions (CEs) by 2030 and to realize carbon neutral by 2060. However, studies in characterizing the CEs of urban residential buildings from life-cycle perspective at regional level are still limited, especially for the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) in China. Here, life cycle assessment method and improved building stock turnover model were employed to quantify the annual CEs of urban residential buildings (including materialization CEs of the newly-built urban residential buildings, operational CEs of the existing urban residential buildings, and CEs generated from the demolition of the existing urban residential buildings) in GBA cities from 2000 to 2018. The results show that the total CEs increased dramatically from 44.5 Mt. CO 2 e in 2000 to 75.1 Mt. CO 2 e in 2018 with an annual growth rate by approximately 3%. The CEs from operation stage accounted for around 70%, and recycling building wastes could reduce 7.5% emissions. Compared with other bay areas globally, the operational CEs of urban residential building in GBA became the highest since 2014. Therefore, climate actions in energy saving and emission mitigation are required. Based on scenario analysis, we estimated that Huizhou city can reach the peak target by 2020 if taking some effective measures. These emission findings could provide data references and suggestions for the low-carbon development path for urban residential buildings in GBA and other global cities. [Display omitted] • This study evaluates the life-cycle carbon emissions of urban residential buildings in bay area. • This study provides a reference for the carbon emission of building unit floor area. • Operation stage is the focus of emission reduction in urban residential buildings. • This study explores the path of peak carbon emissions from residential buildings. [ABSTRACT FROM AUTHOR]

China has demonstrated great commitment to take more vigorous and effective approaches to peak carbon emissions by 2030 and achieve carbon neutrality by 2060. China's actions to mitigate CO 2 emissions are expected to simultaneously reduce co-emitted air pollutants and reduce premature deaths. This study investigates the future changes in international and regional ozone and associated health and economic benefits of stringent climate mitigation policy in China by 2050. Results show that China's stringent mitigation policy positively impacts air quality and public health in China and its downwind transboundary regions, Japan and South Korea. More specifically, approximately 15,800 and 35,550 ozone-related premature deaths will be avoided globally in 2030 and 2050 worldwide, with 78% and 76% happening in China. The avoided ozone-related mortality could save 3 billion USD in 2030 and 10 billion USD in 2050 based on the willingness to pay method. Figure 2 Avoided ozone-related morality under China's strict climate mitigation policy in different regions in 2030 and 2050 [Display omitted] [ABSTRACT FROM AUTHOR]

Achieving the carbon neutral targets before year 2060 is one of the important commitments for mitigating global climate change by Chinese government. However, the manner in which one would maximize the carbon sequestration of the planted forests is still unclear. Estimating accurately the carbon balance in forestry depends highly on the dynamics of numerous delay-released carbon pools (e.g., harvest residues, wood products), thus the strategies used to account for the carbon emissions of these components may have great influences on the decision-making and profitability associated with planted forests. This study developed a tool that allows forest managers and policy makers to analyze the effects of alternative accounting strategies for recognizing carbon emissions on the optimal rotation lengths and profitability of planted forests. The considered carbon balance not only refers to the within-forest pools, e.g., living biomass, harvest residues, annually generated litters and dead trees, but also refers to the outside-forest pools that include wood products, biofuel, operating process and substitution effect. The obtained results indicated that the lengths of optimal forest rotation decreased significantly with increases in site index, planting density and discount rate, while they increased dramatically with increases of carbon price. The gaps in rotation lengths were as large as 13.5 years, 6.9 years, 27.6 years and 11.0 years, respectively for the ranges of site index (10–18 m), planting density (2500–4444 trees per hectare), discount rate (1%–5%), and carbon prices (0–880 CNY/ton CO 2) assumed. The effects of delay-released carbon pools on the optimal rotation lengths were not significant, when the substitution effects of wood products and biofuels were considered under the current carbon trading markets; however, some exceptions were observed when a very high carbon price (880 CNY/ton CO 2) was assumed. [Display omitted] • A management tool that considers carbon balance and wood production was developed. • The optimal rotations are sensitive to forest- and economic-based variables. • The delayed effects of carbon emissions on optimal rotations were offset by substitution effects. • Pricing CO 2 sequestrated in forests can increase optimal rotations and profitability. [ABSTRACT FROM AUTHOR]

• Promote the construction of China's city-level CH 4 emission basic database • Calculate the anthropogenic CH 4 emissions for 340 Chinese cities in 2015 • Analyze the characteristics of anthropogenic CH 4 emissions in Chinese cities • Provide recommendations for China to achieve carbon neutrality by 2060 China attaches great importance to methane (CH 4) emissions, and the "14th Five-Year Plan" will formulate actions related to CH 4 emission reduction. Accounting for and understanding CH 4 emissions at the city level are of great importance because cities are the focus of future mitigation and adaptation activities to address climate change, especially in developing nations. However, existing studies have not yet provided a complete and updated emissions database of city-level CH 4 emissions for China. To promote research on CH 4 emissions accounting, this paper applies a production-based method to calculate anthropogenic CH 4 emissions for 340 Chinese prefecture-level administrative units in 2015 based on multisource statistical information. The CH 4 emission sources considered in this paper are mainly divided into five categories: underground coal mining, rice cultivation, livestock management, straw burning, and waste treatment. The results show that the characteristics of CH 4 emissions in Chinese cities vary significantly and different emission sources present different spatial distribution characteristics. Moreover, there is an obvious single-source dominant pattern in the CH 4 emission structure of Chinese cities. More than 50% of the total CH 4 emissions in more than two-thirds of Chinese cities are from a single source. The accounting results are basically consistent with the official results, and the error range is within 20%, which is within the emission uncertainty range. The main contribution of this paper is the construction of a basic database to support China's efforts to achieve carbon neutrality by 2060. [ABSTRACT FROM AUTHOR]

• An integrated top-down and bottom-up modeling framework was developed. • Analyze low-carbon pathways for Chinese iron & steel industry towards carbon neutrality. • Both the supply-side and demand-side contributions to decarbonization are explored. • Energy-saving retrofitting technologies help short-term CO 2 emissions reduction. • Breakthrough technologies are crucial in achieving carbon neutrality. Iron and steel production in China contributes to 14% of China's total energy-related CO 2 emissions. Decarbonizing the iron and steel sector will therefore play an important role in achieving the goal of carbon neutrality. This study explored possible low-carbon transition pathways for China's iron and steel industry to achieve carbon neutrality by 2050. An integrated approach was developed that combined a computable general equilibrium model and a bottom-up technology-selection module. The results indicated that although energy-saving technologies can reduce CO 2 emissions in the short term, in the long term, adopting breakthrough technologies (e.g., carbon capture and storage (CCS) and hydrogen-based direct reduction (DR)), increasing the share of scrap-based electric arc furnace (EAF) steel production, and decarbonizing upstream energy-supply sectors will be crucial for climate change mitigation. Hydrogen-based DR could be an effective option for CO 2 emission reduction in scenarios where CCS is not available, with its share increasing to 23%–25% by 2050. System-wide cross-sector decarbonization can help achieve climate targets at lower costs through flexible technology combinations and avoid carbon leakage into upstream energy-supply sectors. [ABSTRACT FROM AUTHOR]

About 3 billion people still rely on traditional sources of fuel. Biomass-based fuels were responsible for more than 4 million deaths in 2012. Household energy consumption is steadily increasing across cities due to the urbanization of rural areas, more economic and travel activities. In this review, Multiple Correspondence Analysis (MCA) and other bibliometric tools were applied to determine the conceptual structure and typological thematic areas of household emissions in urban areas. The current state of knowledge and opportunities towards creating carbon-neutral cities indicated that while most of the research was focussed on cities and regions of developed countries and China, the mitigation activities grouped under three broad heads - reducing emissions, consumption and impact of household emissions. Strong heterogeneity between the urban and rural areas, fuel options and human choices gave rise to fuel-stacking in developing countries. Integrated modelling and inclusion of environmental and human behavioural components into economic models were recognised as emerging fields oriented towards a systems approach. Accessibility and availability of clean energy and clean energy appliances were identified as the biggest challenges. To create carbon-neutral urban areas, integrated modelling should include categorization of carbon policy according to local conditions, analysis of feedback loops, embedded emissions, the global and regional impact of household consumption patterns, and uncertainty associated with mitigation measures. [Display omitted] • Carbon neutral cities should have access equality despite income inequality. • Multiple Correspondence Analysis indicated mitigation research focused on emissions, consumption and impacts. • Integrated modelling and general equilibrium models were the two emerging themes. • Risk, uncertainty, embedded emissions and feedback loops should be integrated into emission models. • Availability and accessibility to cleaner fuels is the biggest challenge for creating carbon-neutral cities. [ABSTRACT FROM AUTHOR]