Greenhouse Gas Control Research Articles

LEGISLAÇÃO E REGULAMENTAÇÃO SOBRE A EMISSÃO DE GASES DE EFEITO ESTUFA NA NAVEGAÇÃO: ESTADO, EVOLUÇÃO E IMPACTOS NO BRASIL

This paper analyzes aspects of international and Brazilian legislation on maritime transport activities and the actions of Brazilian authorities and companies in the sector to ensure compliance with existing environmental requirements, with emphasis on the control of greenhouse gas (GHG) emissions. The paper analyzes the ongoing climate change process and international initiatives to mitigate greenhouse gas (GHG) emissions by economic activity sectors, with an emphasis on maritime transport activities in Brazil, A bibliographical research was conducted on greenhouse gas emissions through scientific articles, government websites and websites of various entities and organizations. A survey was conducted on the initiatives of companies in the sector and on the perception of shipping professionals about the state and prospects for progress in the implementation of measures to mitigate emissions on vessels. The results showed that the regional approach complements global regulations and reinforces the need for a coordinated response to address the environmental challenges posed by international shipping and that the integration of these international regulations is essential to promote sustainable practices and ensure global compliance.

Production strategies for controlling greenhouse gas emissions in grass-fed beef production systems

Looking at pasture-based beef cattle production systems, there needs to be more pasture management and low zootechnical indexes, which culminate in low productivity and environmental impact. In this sense, cattle farming has been labeled as harmful to the environment due to the emission of gases that can contribute to the excessive increase in the greenhouse effect. These gases are methane, nitrous oxide, and carbon dioxide, which come from ruminal fermentation, manure fermentation, and biomass management. The objective was to simulate eight scenarios: the first occurred in areas of degradation and desertification of pastures induced by livestock farming, the second occurred with the recovery of degraded pasture areas, the third occurred with the improvement of pasture management, the fourth occurred with the implementation of integrated production systems, the fifth occurred with the improvement in diet quality, the sixth occurred with the association of supplementation strategies for grazing cattle with fattening in confinement, the seventh occurred with the reduction in the feeding cycle production of beef cattle and the eighth occurred with the intensification of land use. It is concluded that the adoption of more intensive production systems proves to be more efficient, both productively and environmentally, by reducing the emission of greenhouse gases and improving zootechnical indices, guaranteeing the supply of animal protein in the face of growing demand globally.

Progress in Corrosion Protection Research for Supercritical CO2 Transportation Pipelines

Carbon Capture, Utilization, and Storage (CCUS) technology is an emergent field with the potential for substantial CO2 emissions reduction, enabling low-carbon utilization of fossil fuels. It is widely regarded as a critical technology for combating global climate change and controlling greenhouse gas emissions. According to recent studies, China has identified CCUS as a key emissions reduction technology in climate change response and carbon neutrality objectives. Within this framework, supercritical CO2 (SC-CO2) transport pipelines are an essential means for efficient and safe transportation of CO2. Corrosion protection of pipelines enhances the efficiency and safety of CCUS technology and supports broader implementation and application. This paper reviews the current research on corrosion protection for SC-CO2 transport pipelines, discusses effect factors, compares various corrosion protection strategies, and analyzes the challenges in corrosion protection of SC-CO2 transport pipelines. It concludes with a perspective on future research and development directions in this field. This paper is dedicated to providing new research strategies for pipeline corrosion protection in CCUS technology in the future, and providing technical support for pipeline corrosion protection in CCUS industrial applications.

Mechanism of Minerals Action in Reservoir During CCS

Abstract The carbon capture and storage (CCS) is one of the most effective ways to control greenhouse gases emissions and mitigate greenhouse effects. There will be a series of effects on the physical properties and chemical composition of the reservoir after CO2 injection. It is of great significance to study the effect of CO2 injection on reservoir for better CO2 storage. In this paper, Through the mechanism model established by numerical simulation technology and the phase permeability hysteresis simulation method, the whole process of reservoir pH, mineral dissolution and precipitation and porosity change during CO2 storage was accurately described. The results indicate that CO2 firstly dissolves in water to form carbonic acid after injection into the reservoir, which will cause a drastic change acid-base properties of reservoir, manifesting as a significant decrease in pH value. Under the effect of H +, Partia mineral components(for example: anorthite) in the reservoir) are dissolved, however, some other minerals (for example: kaolinite and calcite) are precipitated, which significantly change the composition of underground aqueous solution. The reaction rate of CO2-water-rock is very slow. After stopping CO2 injection, the mineralization of all kinds of minerals still goes on for a long time. In addition, due to the effect of CO2-water-rock reaction, a certain increase of reservoir porosity is more conducive to CO2 migration in the reservoir.

Design of Oil Mist and Volatile-Organic-Compound Treatment Equipment in the Manufacturing Plant

To effectively confront the acute challenge of global warming, at the present stage, the Chinese government has designated carbon reduction as the core objective to accomplish the coordinated control of greenhouse gas and pollutant emissions. As China is a major manufacturing country, with the continuous improvement of air emission standards, it is particularly necessary to carry out the design of more efficient volatile organic pollutant emission devices. This study takes a treatment system with a waste gas ventilation volume of 6 × 104 m3·h−1 as an example, adopts the end treatment approach of adsorption and catalytic combustion coupling, and designs a purification device composed of multistage oil-mist recovery, electrostatic adsorption, dry filtration, activated-carbon adsorption and desorption, catalytic combustion, etc. It also employs the fuzzy proportional-integral-derivative fine temperature control algorithm, and the temperature overshoot was decreased by 85%. The average emission concentration of volatile organic compounds at the equipment outlet is 6.56 mg·m−3, and the average removal rate is 93.99%, far surpassing the national emission standards. The device operates efficiently and stably, confirming that the end-coupled treatment system based on the adaptive fuzzy proportional-integral-derivative temperature control strategy can effectively handle volatile organic compounds with oil mist and holds significant promotion and research value.

Mitigation strategies for greenhouse gases to ensure food security

Global warming and food insecurity are global concerns, with agriculture being a major contributor to greenhouse gas emissions. Greenhouse gases such as carbon dioxide, nitrous oxide, and methane, from agricultural activities significantly impact climate change. Approximately 24% of global greenhouse gas emissions come from agriculture. Nitrous oxide is 300 times stronger than carbon dioxide and is mainly produced from organic manure and fertilizers. Methane, another potent greenhouse gas, is released during fermentation, manure management, and burning of residues. Carbon dioxide, a major contributor to climate change, is emitted through farming practices, fertilizers, pesticides, and deforestation. Climate change affects food security by directly impacting crop production and indirectly affecting food availability, cost, and supply chains. Hunger rates have been increasing globally, emphasizing the need to control global warming to reduce food insecurity. This review highlights various mitigation strategies for controlling greenhouse gases from agriculture with improved crop productivity. Soil characterization techniques, such as X-ray computed tomography, tracer and chamber-based methods, help to understand the soil composition for greenhouse gas mitigation strategies. Soil amendments, like biochar application can effectively reduce emissions by modifying microbial activity and biogeochemical processes. Controlled irrigation practices, minimum and zero tillage, and efficient nitrogen fertilizer usage also contribute to greenhouse gas mitigation and improves crop productivity. Strategies such as slow release of fertilizers and the use of inhibitors help to increase nitrogen usage efficiency and reduce nitrous oxide emissions. Implementing these strategies globally is crucial for mitigating greenhouse gas emissions, reducing global warming, and ensuring food security.

Simulation of CO2 hydrate formation in porous medium and comparison with laboratory trial data

The storage of CO2 in gas hydrate form in the pore space in depleted natural gas reservoirs has been considered a method for greenhouse gas control. The formation of CO2 hydrate in porous medium is a strongly coupled Thermal-Hydraulic-Chemical (THC) problem under certain thermodynamic conditions. In this study, laboratory data on CO2 hydrate formation in silica sand, including the profiles of pressure, temperature, the amount of CO2, H2O, and CO2 hydrate, etc., were compared with results from numerical simulations. The minimized deviations between the simulation and experimental results, including the pressure drop, the significant temperature increase caused by hydrate formation, and the amount of CO2, water, and hydrate, were all less than 10 % in the numerical simulations. The sensitivities of the deviations between numerical simulations and experimental data to the domain discretization, thermal conductivity of the silica sand, absolute permeability, and kinetics of CO2 hydrate formation were analyzed. One of the major findings is that CO2 hydrate formation in the porous medium in this study is dominated by the kinetics of chemical reaction, rather than the heat or mass transfer. Another key finding of this study is the acquisition of the modeling parameters of the CO2 storage process in the laboratory-scale sand reservoir, including the thermal conductivity of the silica sand λs = 2.2 W/m/K, the absolute permeability k0 = 3.0 × 10−11 m2, and the kinetic constant Kf0 = 8.4 × 1011 kg/m2/Pa/s and the reduction exponent β = 5.3 in the kinetic model of CO2 hydrate formation. It is noteworthy that the mathematical models and the parameters faithfully fit three independent experiments of Run 1–3. The results of the experiments and corresponding numerical simulations provide a reliable method to evaluate the capacity, technical and commercial feasibility of CO2 storage in marine and permafrost reservoirs.

Optimized strategies for efficient CO2 trapping using hydrate technology by pressure adjustment

The hydrate-based method enhances oceanic CO2 storage capacity and is deemed beneficial for controlling greenhouse gas emissions. However, the non-uniform CO2 hydrate crystal interface in the sub-seabed storage layer acts as a barrier, slowing down mass transfer kinetics. This work employed in-situ nuclear magnetic resonance (NMR) technology to compare three different pressure adjustment strategies and observe CO2 bubble dispersion after hydrate dissociation, secondary nucleation, and crystal growth mechanism, along with pore water changes. The presence of micro/nano CO2 bubbles with high internal pressure and high specific surface area in the dissociation liquid significantly accelerated secondary micro-structural phase transition rates. The optimal hydrate-based CO2 storage efficiency reached up to 81.7 %. Moreover, the secondary formation of CO2 hydrates distributed more uniformly within the large, medium, and small pores and led to a significantly increased residual water conversion rate (reaching up to 88 %) in medium pores. The post-secondary formation of high-density hydrates resulted in low fluid mobility (T1/T2 mostly distributed in the range of 0 ∼ 10) and exhibited a mixed wettability state between pore fluids. Utilizing the “memory effects” of CO2 hydrate effectively overcame late-stage mass transfer barriers of solid hydrates films. Our findings extend the understanding of CO2 hydrate formation kinetics under pressure adjustment strategies.

The Impact of Retrofitting Natural Gas-Fired Power Plants on Carbon Footprint: Converting from Open-Cycle Gas Turbine to Combined-Cycle Gas Turbine

Since retrofitting existing natural gas-fired (NGF) power plants is an essential strategy for enhancing their efficiency and controlling greenhouse gas emissions, this paper compares the carbon footprint of natural gas-fired power generation from an NGF power plant in Brazil (BR-NGF) with and without retrofitting. The former scenario entails retrofitting the BR-NGF power plant with combined-cycle gas turbine (CCGT) technology. In contrast, the latter involves continuing the BR-NGF power plant operation with open-cycle gas turbine (OCGT) technology. Our analysis considers the BR-NGF power plant’s life cycle (construction, operation, and decommissioning) and the natural gas’ life cycle (natural gas extraction and processing, liquefaction, liquefied natural gas transportation, regasification, and combustion). Moreover, it is based on data from primary and secondary sources, mainly the Ecoinvent database and the ReCiPe 2016 method. For OCGT, the results showed that the BR-NGF power plant and the natural gas life cycles are responsible for 620.87 gCO2eq./kWh and 178.58 gCO2eq./kWh, respectively. For CCGT, these values are 450.04 gCO2eq./kWh and 129.30 gCO2eq./kWh. Our findings highlight the relevance of the natural gas’ life cycle, signaling additional opportunities for reducing the overall carbon footprint of natural gas-fired power generation.

Impact of cylinder deactivation on fuel efficiency in off-road heavy-duty diesel engines during high engine speed operation

Off-road heavy-duty diesel engines are equipped with complex aftertreatment systems to meet the stringent EPA Tier 4 emission standards. Traditionally, the thermal management of the aftertreatment system, aimed at efficiently reducing tailpipe emissions, involves controlling engine exhaust flow and temperature. However, this approach often leads to inefficient engine operation, especially in the low to mid-load regions, resulting in higher fuel consumption. Prior studies have highlighted the potential of cylinder deactivation (CDA) in reducing fuel consumption and increasing the exhaust temperature for thermal management in on-road applications. As the significance of controlling greenhouse gas (GHG) emissions from off-road machinery comes into focus, this study aims to experimentally demonstrate the fuel efficiency benefits and efficient aftertreatment thermal management achieved through CDA during high-speed operation on a Tier 4 level off-road heavy-duty diesel engine. In a typical off-road duty cycle, such as Non-Road Transient Cycle (NRTC), about 82.5% of cycle’s energy is produced in the engine speed range of 1750–2200 rpm, prompting investigation into the impact of CDA during high-speed operations. CDA results in airflow reductions and increased exhaust gas temperatures due to lower air–fuel ratio (AFR). The reduced airflow operation minimizes pumping work, allowing for higher open cycle efficiency, and thereby translating into lower fuel consumption. The study reveals a new finding: fuel benefits from CDA extend over a larger load range (up to 8.3 bar BMEP) during high-speed operation in off-road heavy-duty engines compared to findings in on-road heavy-duty engines. This phenomenon can be attributed to sufficient oxygen inducted during CDA operation, resulting from similar turbocharger speeds compared to all-cylinder firing operation, especially at high-loads, thereby maintaining particulate matter (PM) concentration within prescribed constraints. Steady-state test results demonstrate a reduction in fuel consumption from 33.7% at 0.4 bar to 1.4% at 8.3 bar BMEP, at 2100 rpm engine speed.

Integrating genome-and transcriptome-wide association studies to uncover the host-microbiome interactions in bovine rumen methanogenesis.

The ruminal microbiota generates biogenic methane in ruminants. However, the role of host genetics in modifying ruminal microbiota-mediated methane emissions remains mysterious, which has severely hindered the emission control of this notorious greenhouse gas. Here, we uncover the host genetic basis of rumen microorganisms by genome-and transcriptome-wide association studies with matched genome, rumen transcriptome, and microbiome data from a cohort of 574 Holstein cattle. Heritability estimation revealed that approximately 70% of microbial taxa had significant heritability, but only 43 genetic variants with significant association with 22 microbial taxa were identified through a genome-wide association study (GWAS). In contrast, the transcriptome-wide association study (TWAS) of rumen microbiota detected 28,260 significant gene-microbe associations, involving 210 taxa and 4652 unique genes. On average, host genetic factors explained approximately 28% of the microbial abundance variance, while rumen gene expression explained 43%. In addition, we highlighted that TWAS exhibits a strong advantage in detecting gene expression and phenotypic trait associations in direct effector organs. For methanogenic archaea, only one significant signal was detected by GWAS, whereas the TWAS obtained 1703 significant associated host genes. By combining multiple correlation analyses based on these host TWAS genes, rumen microbiota, and volatile fatty acids, we observed that substrate hydrogen metabolism is an essential factor linking host-microbe interactions in methanogenesis. Overall, these findings provide valuable guidelines for mitigating methane emissions through genetic regulation and microbial management strategies in ruminants.

Policy spillovers from climate actions to energy poverty: international evidence

Policies to address climate change have been implemented worldwide in recent years. The core of these policies is to control greenhouse gas (GHG) emissions, which primarily stem from the consumption of fossil fuels. Consequently, the implementation of climate policies can affect other energy-related issues, such as energy poverty, a critical element of the UN Sustainable Development Goals (SDGs). This paper uses cross-country data from 2000 to 2020 to study the possible policy spillovers from climate actions to energy poverty. We show that a spillover effect does exist. In other words, a higher number of climate policies is associated with a lower level of energy poverty. The spillover is realized through improvements in energy efficiency, the promotion of renewable energy, and support for innovations. In addition, legislative policies are found to have stronger spillover effects. While the overall policy effects are positive for executive policies, regulations tend to have negative impacts on energy development. There is also evidence demonstrating heterogeneous effects between long-term and short-term policies, and between developed and developing countries. Discovering this spillover effect gives extra motivation for countries to adopt climate policies and actively seek synergies in achieving broader sustainable goals.

Greenhouse gases emissions and microbial assembly mechanism in constructed wetlands for treating saline-alkali and fluoride-laden drainage water

The drainage from high fluoride saline-alkali paddy fields exacerbates agricultural non-point source pollution. Constructed wetlands (CWs) have proven effective in treating such drainage, yet most research has focused on the response mechanisms of CWs to either saline-alkali or fluoride stress individually. The impact of combined stress of saline-alkali and fluoride on CW’s purification effects and greenhouse gas emissions, along with the underlying microbial mechanisms, remains unclear. We constructed mesocosm-scale CWs with four treatments varying in influent saline-alkali levels: low (LS-CWs), medium (MS-CWs), high (HS-CWs), and non saline-alkali CWs (Control-CWs). Our results show that CWs were effective in treating low and medium saline-alkali wastewater. Under high saline-alkali condition (pH: 9.5; EC: 5 mS/cm), CWs exhibited the highest global warming potential (GWP), exceeding that of Control-CWs, LS-CWs, and MS-CWs by 2.2, 4.2, and 3.9 times, respectively. The “ infer Community Assembly Mechanisms by Phylogenetic-bin-based null model ” (iCAMP) analysis indicated that stochastic processes, particularly drift and diffusion limitation (DL), dominated the community assembly of CWs. Elevated saline-alkali levels may enhance microbial habitat differentiation, increasing DL’s contribution, and raising the modularity and complexity of co-occurrence networks. This might be a strategy for microbial communities to resist environmental pressure and maintain network stability. We also propose suitable areas for CWs establishment considering both purification efficiency and GWP, in Western Jilin Province, a typical saline-alkali region. This study addresses a research gap in understanding pollutant transformation and microbial response mechanisms during treating saline-alkali and fluoride-laden drainage within CWs, providing a theoretical basis for the integrated treatment of sewage and greenhouse gas control in CWs to maximize their environmental benefits in practical applications.

Co-abatement of greenhouse gas and air pollutants in Shanghai, China: Spatial hotspots identification, effects assessment and policy implication

Driving co-abatement of Greenhouse Gas (GHGs) and Air Pollutants (APs) in the city level is crucial for fostering societal green and low-carbon transitions, yet comprehensive and refined researches at this level remain limited. To facilitate urban fine management of GHGs control and APs reduction, this study targeted nine categories of anthropogenic emission sources in Shanghai, a typical megacity of China, analyzing the co-benefits of three types of GHGs (CO2, CH4, N2O) and seven types of APs (SO2, NOx, CO, VOCs, NH3, PM2.5, PM10) via emissions flow, spatial distribution, hotspot regions identification, and scenario prediction. Results highlighted the source heterogeneity of different types and significant contributions of energy consumption. CO2 emissions showed a strong spatial correlation with SO2, NOx, and CO, followed by VOCs and PM. Hotspot regions for CO2-VOCs, CO2-NOx and CO2-SO2 co-abatement included power plants, petrochemical enterprises and chemical industrial parks in the southern coastal areas, iron and steel enterprises and power plants in the northern coastal areas, and airport areas in the central and eastern coastal areas, presenting great potential maximum reduction benefits. Achieving positive co-benefits in industrial sector would depend on the steady decline of CO2 emissions in power generation and steel industries. Introducing carbon capture devices and improving energy efficiency would be more beneficial to CO2 emission reduction, while increasing the share of clean energy and phasing out outdated vehicles, machinery, or production capacities are more effective in reducing APs. These mitigation measures could achieve 68.8 % and 47.6 % reduction for CO2 and APs by 2050, respectively, and the co-effect of CO2 and APs emission reduction would gradually increase with the continuous implementation of these measures.

Study on the synergistic control of nitrogenous emissions and greenhouse gas of ammonia/diesel dual direct injection two-stroke engine

This study developed a numerical model for an ammonia/diesel dual direct-injection two-stroke engine and validated it based on engine bench test results. The engine combustion and emission characteristics were discussed under the cases of different injection parameters, intake temperatures, and exhaust gas re-circulation (EGR) rates. The findings indicate that altering the injection angle of ammonia and diesel sprays impacts the in-cylinder swirl and the ignition timing of the ammonia spray, consequently affecting the heat release phase of ammonia combustion. A suitable arrangement spray plumes can effectively reduce the emissions of unburned ammonia and greenhouse gas (GHG), while increase the emissions of NOx. On the other hand, higher intake temperatures can increase the average in-cylinder temperature, reducing unburned ammonia, N2O and GHG emissions. However, it also results in greater NO emissions, which can affect fuel economy negatively. Furthermore, the use of EGR technology can reduce the combustion temperature, thereby lowering the emission of nitrogen-based pollutants, but it also reduces ammonia combustion efficiency. By simultaneously applying the three aforementioned technologies within a certain range of conditions, it is possible to effectively synergize and control nitrogenous emissions and GHG while maintaining high thermal efficiency of ammonia/diesel dual direct injection engines.

Transition to the Circular Economy: Innovative and Disruptive Production Technologies Adopted by Agribusiness Startups

ABSTRACTThis study aimed to analyze the impact of innovative and disruptive production technologies adopted by Brazilian agribusiness startups on the value chain, contributing to the transition to the circular economy. Qualitative research was carried out through 10 semi‐structured interviews with CEOs of startups in the agribusiness segment, also called agtechs. The results indicate that various disruptive innovative technologies are in use, such as precision agriculture, artificial intelligence, and biotechnology. The adoption of innovative technologies, especially those that have disruptive potential, contributes to the transition to a circular economy. These innovations enhance efficiency, productivity, resource waste reduction, greenhouse gas emission reduction, monitoring, and control. At the same time, they have the potential to contribute to the generation of food security, the minimization of environmental impact, and the promotion of sustainability in agribusiness, making it more resilient. It is concluded that disruptive technologies, especially those originating from Industry 4.0, have the potential to transform the agribusiness industry. They support sustainable and efficient practices and have the potential to replace the lack of human labor in the field. Furthermore, the study expands the theoretical understanding of the role of agtechs in the circular economy and provides practical insights into the formulation of public policies, investments, and business strategies to promote sustainability in the agricultural sector.

Research on Low-carbon Layout and Planning of Urban Space Driven by Sustainable Development

Carbon dioxide emissions, leading to global warming, have threatened human development. It is urgent to control and slow down greenhouse gas emissions to maintain ecologically sustainable development. The energy demand and pollutant emissions generated in the process of urban development are the main reasons leading to climate and environmental change. Scientific planning for cities and construction of low-carbon urban development models are the first work to deal with climate and environmental issues. In view of these problems, the article takes Guangyuan City as an example of low-carbon city construction, through transforming the city's industrial structure, strengthening the energy and science and technology innovation, establishing and improving the low-carbon system and other methods to implement the specific construction of low-carbon city, to build a clean, low- carbon new urban life mode, Make Guangyuan City from 2015 to reach the exploitable hydropower installed capacity of 65% to 80% in 2020. In this paper, we propose a series of specific low- carbon urban spatial layout and planning strategies, which not only in-depth analysis of the key problems in China's urbanization process, such as energy consumption, carbon emissions, etc., but also propose targeted solutions. By implementing these strategies, we can effectively meet the challenges brought about by urbanization and promote the development of Chinese cities in a more low-carbon and sustainable direction.

Effects of aeration control strategies on nitrous oxide emissions in alternating anoxic–oxic sequencing batch reactor systems

Reducing N2O emissions is key to controlling greenhouse gases (GHG) in wastewater treatment plants (WWTPs). Although studies have examined the effects of dissolved oxygen (DO) on N2O emissions during nitrogen removal, the precise effects of aeration rate remain unclear. This study aimed to fill this research gap by investigating the influence of dynamic aeration rates on N2O emissions in an alternating anoxic–oxic sequencing batch reactor system. The emergence of DO breakthrough points indicated that the conversion of ammonia nitrogen to nitrite and the release of N2O were nearly complete. Approximately 91.73 ± 3.35% of N2O was released between the start of aeration and the DO breakthrough point. Compared to a fixed aeration rate, dynamically adjusting the aeration rates could reduce N2O production by up to 48.6%. Structural equation modeling revealed that aeration rate and total nitrogen directly or indirectly had significant effects on the N2O production. A novel regression model was developed to estimate N2O production based on energy consumption (aeration flux), water quality (total nitrogen), and GHG emissions (N2O). This study emphasizes the potential of optimizing aeration strategies in WWTPs to significantly reduce GHG and improve environmental sustainability.

Nitrous oxide (N2O) emission characteristics of farmland (rice, wheat, and maize) based on different fertilization strategies.

Fertilizer application is the basis for ensuring high yield, high quality and high efficiency of farmland. In order to meet the demand for food with the increasing of population, the application of nitrogen fertilizer will be further increased, which will lead to problems such as N2O emission and nitrogen loss from farmland, it will easily deteriorate the soil and water environment of farmland, and will not conducive to the sustainable development of modern agriculture. However, optimizing fertilizer management is an important way to solve this problem. While, due to the differences in the study conditions (geographical location, environmental conditions, experimental design, etc.), leading to the results obtained in the literatures about the N2O emission with different nitrogen fertilizer application strategies have significant differences, which requiring further comprehensive quantitative analysis. Therefore, we analyzed the effects of nitrogen fertilizer application strategies (different fertilizer types and fertilizer application rates) on N2O emissions from the fields (rice, wheat and maize) based on the Meta-analysis using 67 published studies (including 1289 comparisons). For the three crops, inorganic fertilizer application significantly increased on-farm N2O emissions by 19.7-101.05% for all three; and organic fertilizer increased N2O emissions by 28.16% and 69.44% in wheat and maize fields, respectively, but the application of organic fertilizer in rice field significantly reduced N2O emissions by 58.1%. The results showed that overall, the application of inorganic fertilizers resulted in higher N2O emissions from farmland compared to the application of organic fertilizers. In addition, in this study, the average annual temperature, annual precipitation, soil type, pH, soil total nitrogen content, soil organic carbon content, and soil bulk weight were used as the main influencing factors of N2O emission under nitrogen fertilizer strategies, and the results of the study can provide a reference for the development of integrated management measures to control greenhouse gas emissions from agricultural soils.

Distributionally robust newsvendor problem with partial demand information under carbon emission regulations

Carbon emission schemes are widely adopted and implemented in practice to control greenhouse gas emissions. However, a firm restricted by carbon emission schemes with only partial demand information may face greater challenges. In this paper, we investigate an ordering and pricing newsvendor problem with partial demand information, which considers carbon emissions generated from the processes of ordering and disposing of the excess inventory. We propose three distributionally robust models to maximize the worst-case profit under different carbon emission regulations: carbon tax, cap-and-trade and carbon cap, respectively. We derive the implicit solution under the carbon tax scheme and design heuristic algorithms based on Lagrangian relaxation under the cap-and-trade and carbon cap regulations. Numerical analysis indicates: (i) all three regulations are effective in reducing carbon emissions; (ii) the implementation of carbon schemes leads to higher optimal pricing and lower optimal ordering quantity, both carbon tax and carbon cap regulations will always lead to lower profit, while the retailer may benefit from the cap-and-trade regulation by selling out the carbon credit; (iii) the proposed approach performs well under different distribution specific scenarios.