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With the gradual increase of international willingness to reach the carbon peak and carbon neutrality, this paper decomposes the influencing factors of China's carbon emission changes from 2008 to 2019 using the Logarithmic Mean Divisia Index model (LMDI), and analyzes the contribution amount and rate of each influencing factor. The results found that: for the whole country, the cumulative growth of carbon emissions during the study period is about 416,484.47 (104 tons), among which the economic growth effect plays a major role in promoting, with a cumulative contribution rate of 284.16%; The increase in regulation intensity and the optimization of industrial structure, however, suppress carbon emissions well, with a cumulative contribution rate of about – 199.21% and − 64.75%, respectively, during the study period. For economic regions, the cumulative influence direction of each driver is the same as that of the whole country, while the population size effect in the northeast economic region and the regulation input effect in the eastern coastal economic region act in the opposite direction from other economic regions, and the carbon emission reduction direction of the energy intensity effect varies from one economic region to another. Accordingly, this paper proposes policy recommendations to enhance regulatory intensity, optimize industrial and energy consumption structure, implement localized emission reduction strategies, and promote synergistic emission reduction in economic zones. [ABSTRACT FROM AUTHOR]

Nowadays environmental issues have been of great concern to the world, among which the problem of global warming caused by greenhouse gas emissions is particularly prominent. All countries in the Kyoto Protocol and the Paris Agreement have committed to control greenhouse gas emissions, and China, as the largest carbon emitter, has assumed a heavier burden. China has been striving to develop low-carbon technologies such as hydrogen, nuclear, wind, and solar energy, but the most attention should be paid to CCUS, which many scholars have high expectations that CCUS can help China reduce emissions to some extent. Therefore, this paper presents a prediction that CCUS can reduce 3.8% of carbon emissions for China in 2040 when CCUS emission reductions increase at a rate of 30%. The power and chemical industries could reduce carbon emissions by 2.3% and 17.3%, respectively. [ABSTRACT FROM AUTHOR]

Metakaolin (MK) is one of the most sustainable cementitious construction materials, which is derived through a direct heating procedure known as calcination. Calcination process takes place substantially lower temperatures than that required for Portland cement, making it a more environmentally sustainable alternative to traditional cement. This procedure causes the removal of hydroxyl water from the naturally occurring kaolin clay (Al2Si2O5(OH)4 with MK (Al2O3·2SiO2) as its product. Kaolin naturally exists in large amount within 5°29′N–5°35′N and 7°21′E–7°3′E geographical coordinates surrounding Umuoke, Obowo, Nigeria. Alumina and silica are the predominant compounds in MK, which provide it with the pozzolanic ability, known as the 3-chemical pozzolanic potential (3CPP), with high potential as a cementitious material in concrete production and soil stabilization. Over the years, researchers have suggested the best temperature at which MK is derived to have the highest pozzolanic ability. Prominent among these temperature suggestions were 800 °C (3CPP of 94.45%) and 750 °C (3CPP of 94.76%) for 2 h and 5 h' calcination periods, respectively. In this research paper, 11 different specimens of Kaolin clay obtained from Umuoke, Nigeria, were subjected to a calcination process at oven temperatures from 350 to 850 °C in an increment of 50 °C for 1 h each to derive 11 samples of MK. The MK samples and Kaolin were further subjected to X-ray fluorescence), scanning electron microscopy (SEM) and X-ray diffraction (XRD) Brunauer–Emmett–Teller (BET) tests to determine the microstructural behaviour and the pozzolanic properties via the 3CPP as to exploit the best MK with the highest cementing potential as a construction material. The results show that the MK heated at 550 °C and 800 °C produced the highest pozzolanic potentials of 96.26% and 96.28%, respectively. The enhancement in pozzolanic potential at optimum calcination temperature is attributed to an increase in the specific surface area upon calcination of kaolinite confirmed by BET results. The SEM and XRD results further supported the above result with the strengthened crystal structure of the MK at these preferred temperatures. Generally, 550 °C is more preferred due to the less heat energy needed for its formulation during 1 h of calcination, which outperforms the previous results, that suggested 750 °C and 800 °C in addition to longer hours of heat exposure. [ABSTRACT FROM AUTHOR]

Many developing countries are facing the difficulty of choosing between economic growth and energy conservation and emission reduction (ECER). China has strengthened the implementation of ECER by setting environmental accountability as the development goal of local governments, hoping to have better governance effects. To evaluate the actual intervention effect of this approach, this paper constructs panel data covering 46 countries from 1995 to 2014 and uses the difference-in-differences (DID) method and the composite control method to quantitatively analyse the policy effect. The results show that China can effectively curb energy consumption and carbon emission intensity per unit of GDP by adding ECER targets to the government's five-year plan, which has significant effects on ECER. Furthermore, we use an intermediary mechanism to test and identify low-carbon alternatives and an ECER promotion mechanism for technological advancement. The conclusion shows that economic development is compatible with low carbon and energy consumption. Combined with China's long-term goals for ECER, it can be considered that on the road to achieving carbon peaking and carbon neutrality in the future, the economy and tertiary industry should be rationally developed, the degree of urbanization should receive more attention, and the proportion of thermal power generation should be reduced. [ABSTRACT FROM AUTHOR]

With the rapid development of distributed energy resources and natural gas power generation, multi-energy microgrid (MEMG) is considered as a critical technology to increase the penetration of renewable energy and achieve the target of carbon emission reduction. Therefore, this paper proposes a low-carbon economic dispatch model for MEMG to minimize the daily operation cost by considering integrated demand response (IDR) and multistep carbon trading. Specifically, IDR operation includes shifting of shiftable electric load, adjusting of flexible thermal load and cooling load, and it is employed to decrease operation cost. Besides, the multistep carbon trading means that different carbon trading prices correspond to different carbon trading volumes, which is applied to stringently restrict carbon emission. The simulation results show that the proposed model can effectively reduce the carbon emission while greatly decrease the operation cost. [ABSTRACT FROM AUTHOR]

This paper investigates the effects of Emission Trading Scheme (ETS) adoption on the country-level reduction rate of carbon emission. We first used Environmental Kuznets Curve (EKC) tests to group countries into three categories: inverse U-shaped and gamma-shaped EKC for decoupled countries, and a positive linear EKC for non-decoupled countries. We then examined the effectiveness of ETS adoption. We found ETS was effective for both post-industrial and pre-industrial economies. Compared to countries that have not adopted ETS, the carbon emission reduction (increment) rate of decoupled (non-decoupled) countries that have adopted ETS is faster (slower). Furthermore, ETS adoption significantly reduces overall carbon emissions per capita compared to other global events, such as oil crises. The results imply that a market-based mechanism is an effective strategy for achieving sustainable development, thus, providing insights for policymakers and governments to design effective carbon neutrality policies to achieve sustainable development. [ABSTRACT FROM AUTHOR]

Land cover change affects the carbon emissions of ecosystems in some way. The qualitative and quantitative understanding of carbon emissions from human activities (e.g., land cover change, industrial production, etc.) is highly significant for realizing the objective of carbon neutrality. Therefore, this paper used GlobeLand30 land cover maps, annual average normalised difference vegetation index (NDVI) data, annual average net ecosystem productivity (NEP) data and statistical yearbook data from 2000 to 2020 to explore the relationship between land cover change and carbon emissions. Specifically, it included land cover change, carbon storage changes influenced by land cover change, spatial and temporal analysis of carbon sources and sinks, land use intensity change and anthropogenic carbon emissions. The results of the study show that the main land cover changes in Shandong province during 2000–2020 was cultivated land conversion to artificial surfaces. Among them, the area of cultivated land converted to artificial surfaces from 2000 to 2010 was 4930.62 km2, and the proportion of cultivated land converted to artificial surfaces from 2010 to 2020 was as high as 78.35%. The total carbon stock of vegetation affected by land cover change decreased by 463.96 × 104 t and 193.50 × 104 t in 2000–2010 and 2010–2020 respectively. The spatial and temporal distribution of carbon sources and sinks differed more markedly from 2000 to 2020, and land use intensity changes in Shandong Province showed an upward trend. Of the total energy production, industry has the largest energy consumption, followed closely by total energy consumption in transportation, storage and postal services. [ABSTRACT FROM AUTHOR]

The Yellow River basin spans nine provinces and autonomous regions and plays an important role in China's economic and social development and ecological security. However few studies have integrated the concept of carbon neutrality into research to evaluate the carbon-neutral development level. This paper calculates the comprehensive evaluation value of the provincial carbon-neutral capacities comprehensive evaluation index in the Yellow River basin through the driving-force-pressure-state-impact-response (DFPSIR) index system and the global entropy method based on provinces data between 2008 to 2019. The final results indicated that from 2008 to 2019, the carbon-neutral capacities of the provinces in the Yellow River basin were in a state of rapid development and had achieved a grade leap. However, seven provinces had carbon-neutral capacity levels at the Grade III standard in 2019, thereby leaving scope for substantial improvement. Through the above research, we identified the changes in the trend and driving mechanisms of the carbon-neutral capacity of the Yellow River basin and provide a theoretical reference value for a comprehensive realization of carbon neutrality in China in 2060. [ABSTRACT FROM AUTHOR]

Anaerobic co-digestion is an effective method for addressing the issue of a single substrate not being able to achieve optimal conditions for anaerobic digestion. By adjusting the mixture ratio of sewage sludge and food waste to achieve the optimal carbon to nitrogen ratio, the effectiveness of thermophilic–mesophilic temperature phase anaerobic co-digestion (TPAcD) was evaluated in comparison to single phase mesophilic anaerobic co-digestion (MAcD) and thermophilic anaerobic co-digestion (TAcD). The results indicated that TPAcD increased methane yield by 50.3% and 32.7% compared to MAcD and TAcD, respectively. The variation in VFA, pH, and ammonia nitrogen levels demonstrated that TPAcD combines the advantages of both MAcD and TAcD, with a higher hydrolysis rate in the early stage under thermophilic conditions (55 °C) and a suitable environment in the later stage under mesophilic conditions (35 °C). The kinetic parameters of anaerobic co-digestions also demonstrated that TPAcD performs better. Therefore, further research on TPAcD of sewage sludge and food waste is warranted due to its significant improvements in methane production rate, total methane yield, and system stability. Additionally, TPAcD contributes to reducing carbon emissions and supports the realization of "carbon neutrality". [ABSTRACT FROM AUTHOR]

Due to the rapid economic development of globalization and the intensification of economic and trade exchanges, cross-international and regional carbon emissions have become increasingly severe. Governments worldwide establish laws and regulations to protect their countries' environmental impact. Therefore, selecting robustness evaluation models and metrics is an urgent research topic. This article proves the reliability and scientific of the assessment data through literature coupling evaluation, multidisciplinary coupling mathematical model and international engineering case analysis. The innovation of this project's research lies in the comprehensive analysis of the complex coupling effects of various discrete data and uncertainty indicators on the research model across international projects and how to model and evaluate interactive effects accurately. This article provides scientific measurement standards and data support for governments worldwide to formulate carbon tariffs and carbon emission policies. Case analysis data shows that the carbon emission ratio of exporting and importing countries is 0.577:100; the carbon trading quota ratio is 32.50:100. [ABSTRACT FROM AUTHOR]

The present study investigated the difference in transmittance of light carrying opposite spin angular momentum (SAM) and orbital angular momentum (OAM) through chlorella algal fluid with varying concentrations and thicknesses. Our results indicate that, under specific conditions, right-handed light sources exhibit higher transmittance in the algal fluid compared to left-handed light sources. Furthermore, we observed that light with OAM also demonstrated higher transmittance than other types of light sources, leading to faster cell density growth of Chlorella. Interestingly, we also discovered that light with OAM stimulates Chlorella to synthesize more proteins. These findings provide different insights for selecting appropriate light sources for large-scale algae cultivation, and may facilitate the realization of carbon peaking and carbon neutrality in the future. [ABSTRACT FROM AUTHOR]

As a major carbon emitter, the power sector plays a crucial role in realizing the goal of carbon peaking and carbon neutrality. This study constructed a low-carbon power system based on the LEAP model (LEAP-GBA) with 2020 as a statistic base aiming of exploring the low-carbon transformation pathway of the power sector in the Guangdong–Hong Kong, and Macao Greater Bay Area (GBA). Five scenarios are set up to simulate the demand, power generation structure, carbon emissions, and power generation costs in the power sector under different scenarios. The results indicate that total electricity demand will peak after 2050, with 80% of it coming from industry, buildings and residential use. To achieve net-zero emissions from the power sector in the GBA, a future power generation mix dominated by nuclear and renewable energy generation and supplemented by fossil energy generation equipped with CCUS technologies. BECCS technology and nuclear power are the key to realize zero carbon emissions from the power sector in the GBA, so it should be the first to promote BECCS technology testing and commercial application, improve the deployment of nuclear power sites, and push forward the construction of nuclear power and technology improvement in the next 40 years. [ABSTRACT FROM AUTHOR]

Global greenhouse gas emission, major factor driving climate change, has been increasing since nineteenth century. STIRPAT and CEVSA models were performed to estimate the carbon emission peaks and terrestrial ecosystem carbon sinks at the provincial level in China, respectively. Utilizing the growth characteristics and the peak time criteria for the period 1997–2019, the patterns of energy consumption and CO2 emissions from 30 Chinese provinces are categorized into four groups: (i) one-stage increase (5 provinces), (ii) two-stage increase (10 provinces), (iii) maximum around 2013 (13 provinces), and (iv) maximum around 2017 (2 provinces). According to the STIRPAT model, the anticipated time of peak CO2 emissions for Beijing from the third group is ~ 2025 in both business-as-usual and high-speed scenarios. For Xinjiang Uygur autonomous region from the first group and Zhejiang province from the second group, the expected peak time is 2025 to 2030. Shaanxi province from the fourth group is likely to reach carbon emission peak before 2030. The inventory-based estimate of China's terrestrial carbon sink is ~ 266.2 Tg C/a during the period 1982–2015, offsetting 18.3% of contemporary CO2 emissions. The province-level CO2 emissions, peak emissions and terrestrial carbon sinks estimates presented here are significant for those concerned with carbon neutrality. [ABSTRACT FROM AUTHOR]

Based on the whole life cycle theory, the carbon effect of three different sizes of high-standard basic farmland construction projects is measured and analysed. The results show that the carbon emissions generated during the construction of high-standard basic farmland projects and the carbon absorption capacity at the later stage are different for projects of different sizes. The carbon emissions of different scales of high-standard basic farmland projects will increase during the construction stage. The results of carbon effect changes in the later operation and management stage show that the high-standard basic farmland construction projects will help reduce the carbon emissions of the field ecosystem where the farmland is located and increase its carbon sink capacity after the completion of construction, which is more obvious in larger projects. The emission reduction and carbon sequestration capacity of the farmland after remediation are improved to different degrees, which is more conducive to the ecological development of agricultural production and ecological environmental protection in the relevant areas. The study contributes to the green development of farmland, which is of some significance for the sustainable development of agriculture in Tianjin and the whole country. [ABSTRACT FROM AUTHOR]

Forests play a crucial role in mitigating climate change and reducing emissions as a major carbon sink. However, its value in removing carbon dioxide (CO2) from the atmosphere is always underestimated in natural capital (NC) accounting and sustainability assessments. This study predicted Japan's forest CO2 removal by afforestation and forest management and its monetary value until 2042 from national to gridded level, with statistical data and complementary satellite data products, and explored how that CO2 removal will contribute to sustainable development under the inclusive wealth (IW) framework. The results show that: (1) the annual CO2 removal by forests has the potential to offset 15.3% of the emission and increase NC by 6.8% in Japan, significantly contributing to carbon neutrality and IW growth; (2) the total CO2 removal in exiting forests will peak at around 2030 and then decrease, but expanding afforestation could offset that decrease in later years; (3) the spatial distribution patterns of IW and forest CO2 removal are opposite. This indicates a national carbon trading market could create new wealth for rural communities where vast forests exist, and then effectively balance the inequal urban–rural development in Japan. The explicit spatial information of this study could provide valuable information for differentiating policy priorities of forestry planning and sustainable development in different local communities. [ABSTRACT FROM AUTHOR]

Social reforestation programs plant trees on degraded, uncultivated land in low-income regions to allow the local population to generate income from selling wood products and—in case of agroforestry systems—to grow food. For fundraising it is of interest to demonstrate not only positive social impacts but also environmental ones. Proving negative greenhouse gas (GHG) emissions would allow the programs to enter the market for carbon offsetting projects and liberate further funding. In a case study, a social reforestation program in Kalimantan, Indonesia, is analyzed. GHG emissions (according to ISO 14067, PAS 2050 and EU ILCD Handbook for LCA) of the main product, laminated veneer lumber plywood, are determined as 622 and 21 kg CO2-e/m3 for short-term and long-term (above 100 years) plywood use, respectively. Switching to lignin-based resins and renewable electricity could reduce emissions down to − 363 kg CO2-e/m3 for long-term use. The analyzed agroforestry system produces almost carbon–neutral plywood today and could be climate positive in the mid-term. [ABSTRACT FROM AUTHOR]

Biomass waste streams are a possible feedstock for a range of eco-friendly products and a crucial alternative energy source for achieving carbon neutrality; therefore, the efficient management of biomass waste has taken on a greater significance in recent years. Due to its well-comparable physic-chemical properties with fossil diesel, biodiesel is a potential substitute for fossil fuel. This study aimed to synthesize biodiesel from the widely available non-edible seed oil of Sisymbrium irio L. (a member of the Brassicaceae family) via a transesterification procedure over a homemade TiO2 catalyst. At 1:16 oil to methanol ratio, 93% biodiesel yield was obtained over 20 mg catalyst at 60 °C and 60 min. The ASTM methods were used to analyze the fuel properties. The quantitative and qualitative analysis was performed by FT-IR, GC-MS, and NMR spectroscopy. GC-MS study confirms 16 different types of fatty acids of methyl esters. FT-IR analysis showed important peaks that confirm the successful occurrence of biodiesel. 1H-NMR and 13C-NMR showed important peaks for converting triglycerides into corresponding FAMEs. The acid value (0.42 mg KOH/mg/kg), flash point (106 °C), and water content (0.034) of biodiesel are below the specified limit of ASTM D6751 whereas kinetic viscosity (3.72 mm2/s), density (0.874 kg/L), cloud point (− 4.3 °C) and pour point (− 9.6 °C) and high heating value (41.62 MJ/kg) fall within the specified range of ASTM D6751 test limit. The Unsaturation degree and oxidative stability of biodiesel are above ASTM D6751 test limit. The physic-chemical properties of the SIB confirm that it is eco-friendly fuel and a competitive source for manufacturing biodiesel on a commercial scale. Furthermore, the SIB is engine friendly and has good fuel efficacy. [ABSTRACT FROM AUTHOR]

There are concerns that groundwater use for irrigation and for urban water supply is unsustainable in some parts of Bangladesh, particularly in the agriculturally productive northwest region. We use an integrated population – GDP – food – water model to examine water demand to 2100 in Bangladesh in development scenarios relevant to food and water security. The results indicate that irrigation water demand is projected to increase in coming decades, but later in the century it may decrease due to increasing crop yields and a falling population. The increased demand is greatest in the northwest region and, if unchecked, would increase concerns there about the unsustainable use of groundwater. The growth in demand is determined particularly by growth in crop yields, population growth and the fraction of food demand satisfied by imports. An extreme hot-dry climate change scenario has a lesser impact. This suggests that, in principle, Bangladesh can offset the impacts of climate change on irrigation water demand through its domestic policies. Urban water use currently also leads to concerns over unsustainable groundwater use. Our results suggest that urban water demand is likely to grow proportionately significantly more than irrigation water demand. Alternative sources for urban water are therefore urgently required. [ABSTRACT FROM AUTHOR]

With the improvement of people's living standards, they have higher requirements for indoor thermal comfort in the cold season. Solar wall utilizing solar energy for heating can reduce carbon emissions and achieve carbon neutrality. In the aspect of solar wall research, the influence of wall structure on the thermal performance of double-channel porous solar wall is limitedly investigated. In fact, the optimization design of wall structure is important for the thermal performance of solar wall and its applications. Therefore, a simplified three dimensional room model is built to study the influence of the wall structure on the thermal performance of porous solar wall by numerical simulation. With this model, different channel spacing and thickness of porous walls were used to determine the optimal design for a double-channel porous solar wall in terms of enhancing the heat storage. Moreover, the influence of the surface emissivity on the characteristics of heating and temperature field of double-channel porous solar wall are studied based on the optimal structure. The CFD simulation results indicate that the optimal structure parameters should include spacing of 0.08 m for channel 1, the porous wall thickness should be 0.08 m, and the air channel 2 spacing should be 0.06 m. The temperature of air channel 1 and air channel 2, the indoor temperature, and the heat storage of porous wall decrease with the increase of the surface emissivity of the porous wall. In order to improve the heat storage performance of double-channel porous solar wall, the outer surface of the porous wall should use a lower emissivity material. The outer surface emissivity of porous wall has a significant impact on the heat storage of the porous wall and little effect on the thermal storage wall. The temperature of porous wall is always higher than that of outdoor environment temperature. [ABSTRACT FROM AUTHOR]

Food systems (FSs) emit ~ 20 GtCO2e/y (~ 35% of global greenhouse gas emissions). This level tends to raise given the expected increases in food demands, which may threaten global climate targets. Through a rapid assessment, evaluating 60+ scenarios based on existing low-emission and carbon sequestration practices, we estimate that intensifying FSs could reduce its emissions from 21.4 to − 2.0 GtCO2e/y and address increasing food demands without relying on carbon offsets (e.g., related to afforestation and reforestation programs). However, given historical trends and regional contexts, a more diverse portfolio of practices, including diet shifts and new-horizon technologies, will be needed to increase the feasibility of achieving net-zero FSs. One likely pathway consists of implementing practices that shift food production to the 30th-percentile of least emission-intensive FSs (~ 45% emissions reduction), sequester carbon at 50% of its potential (~ 5 GtCO2e/y) and adopt diet shifts and new-horizon technologies (~ 6 GtCO2e/y). For a successful transition to happen, the global FSs would, in the next decade (2020s), need to implement cost-effective mitigation practices and technologies, supported by improvements in countries' governance and technical assistance, innovative financial mechanisms and research focused on making affordable technologies in the following two decades (2030–2050). This work provides options and a vision to guide global FSs to achieving net-zero by 2050. [ABSTRACT FROM AUTHOR]