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Objectives This study compared greenhouse gas emissions from various biological treatment processes at wastewater treatment plants in City A, Gyeongsangbuk-do. Methods Four wastewater treatment plants were selected by size and treatment process, and flow rate and water quality parameters from 2020 to 2022 were used. The amount of greenhouse gases such as methane, nitrous oxide, and carbon dioxide generated was calculated according to the IPCC and Ministry of Environment calculation formulas. Results and Discussion Regardless of the biological wastewater treatment processes, the greenhouse gas emissions of all plants were higher according to the Ministry of Environment standards than the IPCC method. However, this may be because it was not applied to variables that are difficult to confirm, such as correction coefficients. Among biological treatment processes, the greenhouse gas emissions of A2O were higher than those of SBR. Conclusion The results of this study can be used to calculate greenhouse gas emissions from biological wastewater treatment processes and prepare their reduction plans.

Nitrous oxide (N2O) is an ozone-depleting greenhouse gas that contributes significantly to the carbon footprint of a wastewater treatment plant (WWTP). Plant-specific measurement campaigns are required to reliably quantify the emission level that has been found to significantly vary between WWTPs. In this study, the N2O emissions were quantified from five full-scale WWTPs during 4–19-day measurement campaigns conducted under both cold period conditions (water temperature below 12 °C) and warm period conditions (water temperature from 12 to 20 °C). The measurement data were studied alongside long-term monitoring data from a sixth WWTP. The calculated emission factors (EFs) varied from near 0 to 1.8% relative to the influent total nitrogen load. The results confirmed a significant seasonality of N2O emissions as well as a notable variation between WWTPs in the emission level, which a single fixed EF cannot represent. Wastewater temperature was one explanatory factor for the emission seasonality. Both low and high emissions were measured from denitrifying–nitrifying activated sludge (AS) processes, while the emissions from only nitrifying AS processes were consistently high. Nitrite (NO2-) at the end of the aerobic zones of the AS process was linked to the variability in N2O emissions during the cold period. HIGHLIGHTS N2O emissions exhibit seasonal variability that can be linked to wastewater temperature.; Fixed emission factors are highly unrepresentative of the variability in N2O emissions between treatment plants.; N2O emissions are higher in only nitrifying processes than in nitrifying–denitrifying processes.; Process disturbances may significantly affect the N2O emission level during short-term monitoring.;

Ruminal methane production functions as the main sink for metabolic hydrogen generated through rumen fermentation and is recognized as a considerable source of greenhouse gas emissions. Methane production is a complex trait affected by dry matter intake, feed composition, rumen microbiota and their fermentation, lactation stage, host genetics, and environmental factors. Various mitigation approaches have been proposed. Because individual ruminants exhibit different methane conversion efficiencies, the microbial characteristics of low-methane-emitting animals can be essential for successful rumen manipulation and environment-friendly methane mitigation. Several bacterial species, including Sharpea, uncharacterized Succinivibrionaceae, and certain Prevotella phylotypes have been listed as key players in low-methane-emitting sheep and cows. The functional characteristics of the unclassified bacteria remain unclear, as they are yet to be cultured. Here, we review ruminal methane production and mitigation strategies, focusing on rumen fermentation and the functional role of rumen microbiota, and describe the phylogenetic and physiological characteristics of a novel Prevotella species recently isolated from low methane-emitting and high propionate-producing cows. This review may help to provide a better understanding of the ruminal digestion process and rumen function to identify holistic and environmentally friendly methane mitigation approaches for sustainable ruminant production.

Abstract Saltmarshes are suffering from severe degradation due to anthropogenic activities, leading to the loss of blue carbon and greenhouse gas (GHG) emissions. Given the significant potential of biochar in mitigating climate change, adding biochar to saltmarshes would alleviate this situation. This study investigated the effects of different biochar (made from Spartina alterniflora, corn straw, and Laminaria japonica) and their aged biochar on the carbon fraction contents, GHG emissions, and microbial community structure of saltmarsh soils with allochthonous organic matter (Enteromorpha prolifera) addition. After 60 days of incubation, total organic carbon (TOC) loss and global warming potential (GWP) of biochar-amended soils were reduced by 67.29–124.33% and 4.91–123.24%, respectively (p

Numerous studies have explored the links between climate change and military conflicts. This study delves into the types and intensities of conflicts likely caused by climate change in developing countries from 1995 to 2020. Through a country-year panel analysis, it isolates the impact of rising global greenhouse gas emissions on conflict occurrence. Findings consistently show a significant positive association between greenhouse gas emissions and military conflicts, especially low-intensity and internationalized intrastate conflicts. Additional tests confirm these results' robustness, including heterogeneity analysis, substitution of key explanatory variables, sensitivity analysis, and alternative analytical methods. The analysis highlights how environmental scarcity due to climate change drives small-scale conflicts within countries, while geopolitics and environmental scarcity also lead to internationalized intrastate wars. The study recommends that developed countries and the international community support developing countries in building resilience against climate change and advocates for collaborative efforts to mitigate its adverse effects on global security.

Scope 1, 2, and 3 net zero is a major technological challenge for the chemical industry in Japan, but a failure or even a delay in achieving this goal could result in exclusion from international financing and supply chains. This study presents, for the first time to the best of our knowledge, multiple quantitative pathways from today until 2050 for the chemical industry operating in Japan to reach scope 1, 2, and 3 net zero, using a demand-supply model. Through these pathways, this study aims to provide fundamental and strategic insights into necessary actions for net zero. We demonstrate that, amid possible demand reduction through population decline and advances in circularity, securing access to bio-based feedstock as well as carbon capture and storage (CCS) is essential to avoid a supply limit that could be imposed under scope 3 net zero. Given the uncertainty of Japan’s access to both, the chemical industry should pursue both concurrently, while maximizing recycling. Specifically, it should secure long-term and stable sources of sustainable bio-based feedstock and aid in implementing carbon dioxide capture from incinerators in waste management. These implications could also apply to chemical industries in other countries and regions with similar constraints.

As a densely populated country experiencing rapid economic growth, Bangladesh faces a surging demand for energy. Despite efforts to develop renewable energy sources, coal remains a significant share of the energy mix with a consumption of 2,099,900 tons. However, conventional coal utilization raises environmental concerns like greenhouse gas emissions and other hazardous pollutants. To tackle these issues, viable solutions like clean coal technologies come into play. These encompass high-efficiency low-emission (HELE) power stations, carbon capture utilization and storage (CCUS) systems, integrated gasification combined cycle (IGCC), as well as supercritical and ultra-supercritical steam cycles (S/USC), providing adequate means to reduce the ecological effects tied to coal-powered electricity production. This paper asserts that the strategic adoption of clean coal technologies can play a pivotal role in shaping Bangladesh's sustainable energy future, contingent upon robust policy frameworks, environmental impact and recommend that the government must incentivize HELE, CCUS, and clean coal as well as promote international collaboration. Moreover, modern coal preparation techniques and the future research direction are also discussed in this paper and additionally this study suggests that HELE technologies are more suitable for Bangladesh than other current technologies. These strategies have the potential to yield enhanced economic benefits and offer viable solutions for achieving the clean and efficient conversion of coal resources.

Potatoes (Solanum tuberosum L.) are the third largest food crop globally and are pivotal for global food security. Widespread N fertilizer waste in potato cultivation has caused diverse environmental issues. This study employed microbial metagenomic sequencing to analyze the causes behind the declining N use efficiency (NUE) and escalating greenhouse gas emissions resulting from excessive N fertilizer application. Addressing N fertilizer inefficiency through breeding has emerged as a viable solution for mitigating overuse in potato cultivation. In this study, transcriptome and metabolome analyses were applied to identify N fertilizer-responsive genes. Metagenomic sequencing revealed that excessive N fertilizer application triggered alterations in the population dynamics of 11 major bacterial phyla, consequently affecting soil microbial functions, particularly N metabolism pathways and bacterial secretion systems. Notably, the enzyme levels associated with NO3- increased, and those associated with NO and N2O increased. Furthermore, excessive N fertilizer application enhanced soil virulence factors and increased potato susceptibility to diseases. Transcriptome and metabolome sequencing revealed significant impacts of excessive N fertilizer use on lipid and amino acid metabolism pathways. Weighted gene co‑expression network analysis (WGCNA) was adopted to identify two genes associated with N fertilizer response: PGSC0003DMG400021157 and PGSC0003DMG400009544.

Simple Summary: There is increasing pressure on dairy systems worldwide to reduce greenhouse gas (GHG) emissions. Anticipated improvements in animal welfare and reduced mortality and disease rates are expected to result in increased animal productivity, hence reducing GHG emissions per unit of output. There has been a lack of focus on quantifying the intensity of GHG emissions and their impact on the health of dairy cows, encompassing both subclinical and clinical problems. The initial indications of illnesses in dairy cows typically manifest as a decline in both feed consumption and milk production. The implementation of emission-reducing strategies and the maintenance of optimal animal welfare are suggested as effective approaches to improve the sustainability of modern dairy production. More information regarding animal health prior to animal mortality is required to enhance the precision of the estimate for GHG emission intensity. Through the analysis of animal health data prior to mortality, a more accurate estimation of GHG emission intensity can be attained. This will allow dairy producers to have a better understanding of the environmental consequences of their operations and make well-informed choices regarding ways to reduce emissions. In addition, placing a high priority on achieving the best possible conditions for animal welfare not only supports the long-term viability of dairy production, but also guarantees the health and happiness of the cows. This, in turn, can result in enhanced overall productivity and a decrease in the occurrence of diseases. Therefore, it is essential to adopt a comprehensive approach that considers both environmental and animal health aspects to advance a sustainable and efficient dairy sector. Furthermore, the integration of technology such as precision farming and data analytics can significantly augment the efficiency and sustainability of dairy operations. The dairy industry is facing criticism for its role in exacerbating global GHG emissions, as climate change becomes an increasingly pressing issue. These emissions mostly originate from methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2). An optimal strategy involves the creation of an economical monitoring device to evaluate methane emissions from dairy animals. Livestock production systems encounter difficulties because of escalating food demand and environmental concerns. Enhancing animal productivity via nutrition, feeding management, reproduction, or genetics can result in a decrease in CH4 emissions per unit of meat or milk. This CH4 unit approach allows for a more accurate comparison of emissions across different animal production systems, considering variations in productivity. Expressing methane emissions per unit allows for easier comparison between different sources of emissions. Expressing emissions per unit (e.g., per cow) highlights the relative impact of these sources on the environment. By quantifying emissions on a per unit basis, it becomes easier to identify high-emission sources and target mitigation efforts accordingly. Many environmental policies and regulations focus on reducing emissions per unit of activity or output. By focusing on emissions per unit, policymakers and producers can work together to implement practices that lower emissions without sacrificing productivity. Expressing methane emissions in this way aligns with policy goals aimed at curbing overall greenhouse gas emissions. While it is true that total emissions affect the atmosphere globally, breaking down emissions per unit helps to understand the specific contributions of different activities and sectors to overall greenhouse gas emissions. Tackling cattle health issues can increase productivity, reduce GHG emissions, and improve animal welfare. Addressing livestock health issues can also provide favourable impacts on human health by reducing the prevalence of infectious illnesses in livestock, thereby mitigating the likelihood of zoonotic infections transmitting to humans. The progress in animal health offers the potential for a future in which the likelihood of animal diseases is reduced because of improved immunity, more effective preventative techniques, earlier identification, and innovative treatments. The primary objective of veterinary medicine is to eradicate clinical infectious diseases in small groups of animals. However, as the animal population grows, the emphasis shifts towards proactive treatment to tackle subclinical diseases and enhance production. Proactive treatment encompasses the consistent monitoring and implementation of preventive measures, such as vaccination and adherence to appropriate nutrition. Through the implementation of these measures, the livestock industry may enhance both animal well-being and mitigate the release of methane and nitrous oxide, thereby fostering environmental sustainability. In addition, advocating for sustainable farming methods and providing farmers with education on the significance of mitigating GHG emissions can bolster the industry's endeavours to tackle climate change and infectious illnesses. This will result in a more robust and environmentally sustainable agriculture industry. This review seeks to conduct a thorough examination of the correlation between the health condition of cattle, the composition of milk produced, and the emissions of methane gas. It aims to identify areas where research is lacking and to provide guidance for future scientific investigations, policy making, and industry practices. The goal is to address the difficulties associated with methane emissions in the cattle industry. The primary global health challenge is to identify the causative relationship between climate change and infectious illnesses. Reducing CH4 and N2O emissions from digestive fermentation and animal manure can be achieved by improving animal well-being and limiting disease and mortality. [ABSTRACT FROM AUTHOR]

Paddy residue is generated as a post-harvest by-product and farmers dispose of such residue in different ways, including in-situ open burning. Burning paddy residue results in a large loss of plant-essential nutrients in addition to polluting the environment and harming human health. In emission inventorying, particularly in the Intergovernmental Panel on Climate Change—greenhouse gas inventory process, estimating emissions due to burning paddy residue is essential. The present study aimed at providing country-specific information in relation to the in-situ open burning of paddy residue in Sri Lanka. Farmer surveys were conducted in selected five administrative divisions (districts) under wet, dry, intermediate and semi-arid climatic zones of Sri Lanka. For the calculations and analyses, the two cultivation seasons, Yala and Maha of the 2015/2016 cultivation year were considered. Fractions of paddy residue burnt, area burnt and emissions due to paddy residue burning were calculated. The highest percentage of burnt paddy residue (13.51%) was recorded from Anuradhapura District and the lowest percentage of burnt paddy residue (1.42%) was found in Kurunegala District. The highest percentage of area burnt was 13.47% in Anuradhapura District during the Maha season and 8.20% of the area was burnt during the Yala in Kurueagala District. Carbon monoxide (CO) was the highest emission due to paddy residue burning followed by methane (CH4). The study's major findings could be incorporated into future national GHG inventories as country-specific information to be used with IPCC Tier 2 approach, to calculate the emissions from in-situ open burning of paddy residue. [ABSTRACT FROM AUTHOR]

Food waste is a global concern, with significant quantities of edible food being discarded every day. However, innovative conversion technologies have emerged to effectively transform this waste into valuable animal feed. This review paper provides a comprehensive examination of the conversion technologies used to transform food waste into animal feed, along with an analysis of the environmental benefits associated with these processes. The paper delves into various conversion methods such as anaerobic digestion, insect-based conversion, and microbial fermentation along with exploring their mechanisms and suitability for converting food waste into valuable animal feed resources. Additionally, the environmental benefits, including waste reduction, greenhouse gas emission reduction, and resource conservation, are discussed in detail. The review highlights the potential of these technologies to address the pressing issue of food waste while contributing to a more sustainable and resource-efficient food system. The findings of this review emphasize the importance of adopting and further developing these conversion technologies as a means to mitigate environmental impacts, promote circular economy principles, and enhance the overall sustainability of the food and agriculture sector. [ABSTRACT FROM AUTHOR]

Methane (CH4) is a powerful greenhouse gas with ongoing efforts aiming to quantify and map emissions from natural and managed ecosystems. Wetlands play a significant role in the global CH4 budget, but uncertainties in their total emissions remain large, due to a combined lack of CH4 data and fuzzy boundaries between mapped ecosystem categories. European floodplain meadows are anthropogenic ecosystems that originated due to traditional management for hay cropping. These ecosystems are seasonally inundated by river water, and straddle the boundary between grassland and wetland ecosystems; however, an understanding of their CH4 function is lacking. Here, we established a replicated outdoor floodplain‐meadow mesocosm experiment to test how water table depth (45, 30, 15 cm below the soil surface) and plant composition affect CH4 fluxes over an annual cycle. Water table was a major controller on CH4, with significantly higher fluxes (overall mean 9.3 mg m−2 d−1) from the high (15 cm) water table treatment. Fluxes from high water table mesocosms with bare soil were low (mean 0.4 mg m−2 d−1), demonstrating that vegetation drove high emissions. Larger emissions came from high water table mesocosms with aerenchymatous plant species (e.g. Alopecurus pratensis, mean 12.8 mg m−2 d−1), suggesting a role for plant‐mediated transport. However, at low (45 cm) water tables A. pratensis mesocosms were net CH4 sinks, suggesting that there is plasticity in CH4 exchange if aerenchyma are present. Plant cutting to simulate a hay harvest had no effect on CH4, further supporting a role for plant‐mediated transport. Upscaling our CH4 fluxes to a UK floodplain meadow using hydrological modelling showed that the meadow was a net CH4 source because oxic periods of uptake were outweighed by flooding‐induced anoxic emissions. Our results show that floodplain meadows can be either small sources or sinks of CH4 over an annual cycle. Their CH4 exchange appears to respond to soil temperature, moisture status and community composition, all of which are likely to be modified by climate change, leading to uncertainty around the future net contribution of floodplain meadows to the CH4 cycle. [ABSTRACT FROM AUTHOR]

A greenhouse gas sensor has been developed to simultaneously detect multiple gas species within a hollow-core photonic bandgap fiber (HC-PBF) structure entirely composed of fibers. To enhance sensitivity, the gas cell consists of HC-PBF enclosed between two single-mode fibers fused with a reflective end surface to double the absorption length. The incorporation of side holes for gas diffusion allows for analysis of the relationship between gas diffusion speed, number of drilled side holes, and energy loss. As the number of drilled holes increases, the response time decreases to less than 3 min at the expense of energy loss. Gas experiments demonstrated detection limits of 0.1 ppm for methane and 2 ppm for carbon dioxide, with an average time of 50 s. In-situ testing conducted in rice fields validates the effectiveness of the developed gas detection system using HC-PBF cells, establishing all-fiber sensors with high sensitivity and rapid response. [ABSTRACT FROM AUTHOR]

With the rapid expansion of agriculture on saline–alkaline soils, environmental problems such as increased greenhouse gas (GHG) emissions, eutrophication and soil degradation are becoming increasingly serious. To clarify the characteristics of carbon (C) and nitrogen (N) cycling and their loss mechanisms in cultivated saline–alkaline soils, an undisturbed soil column experiment was conducted to analyse C and N leaching and GHG emissions by applying different fertilizer rates. The experiment had six treatments using N‐(NH4)SO4 over a 40‐day seedling stage, with and without maize. Treatments were: no N with maize (0Nmaize: 0 kg N ha−1), reduced N with maize (RNmaize: 63 kg N ha−1), conventional N with maize (CNmaize: 160 kg N ha−1) and their equivalents without maize (0Nsoil: 0 kg N ha−1; RNsoil: 63 kg N ha−1; CNsoil: 160 kg N ha−1). The results indicated that reduced N with maize reduced the N2O emission by 21%, with N leaching (TN: 41%, NO3−–N: 19%, NH4+ − N: 63%) within 15 days after fertilization, but had no significant effect on CH4 emission compared to conventional N with maize. Therefore, reduced N with maize had the smallest N loss, which accounted for 1.5% of the relative percentage of N flow including N2O (0.3%), N leaching (2%), aboveground biomass N (76%) and root biomass N (22%). Compared to conventional N with maize, reduced N with maize significantly reduced N leaching by 40% because conventional N with maize greatly exceeded the crop N uptake when maize root length was only within 20 cm. Reduced N without maize reduced CO2 emission (19%) compared to conventional N without maize. Uncultivated saline–alkaline soils face greater N overuse and leaching risk because higher NO3−–N leaching (6.9 mg L−1) that occurred in bare soils without fertilization, which increased by 2.6–3.6 times when the N input increased from 63 to 160 kg N ha−1 compared to control. In conclusion, reducing conventional N fertilizer inputs by 60% is not only an effective strategy to reduce CO2 and N2O emission and N leaching but also effectively absorbs C, and the N retained in the soil tillage layer can help to meet maize seedling growth requirements in Solonchaks. [ABSTRACT FROM AUTHOR]

This paper clarifies the farm applicability and feasibility of spreading biodegradable plastic film mulching for garlic production to ensure the green and sustainable development of the garlic industry. We set up a field trial of garlic planting with biodegradable plastic film mulching (BM) and plastic film mulching (PM), using no film mulching (CK) as the control, and measured CH4 and N2O emissions in the garlic fields. The yield-scaled global warming potential, carbon footprint, and net ecosystem economic benefit (NEEB) were used to assess the comprehensive impact of the different treatments. Compared to the CK, film mulching significantly increased CH4 absorption, with significantly higher seasonal cumulative CH4 emissions (20.5%) in BM than PM, but significantly increased N2O emissions, with significantly lower seasonal cumulative N2O emissions (23.53%) in BM than PM. Both BM and PM improved garlic yield, with PM significantly increasing garlic yield by 18.86% compared to the CK. Moreover, film mulching significantly decreased the yield-scaled global warming potential (by 52.06% and 40.82% in PM and BM, respectively). PM had a significantly higher carbon footprint than BM. Film mulching improved NEEB by 9.29–11.78%. Considering crop yields and environmental benefits, we propose BM as an effective method for a green and efficient garlic production. [ABSTRACT FROM AUTHOR]

In this research, the methodology and solution for combustion performance and emission control of gas turbine engine have been discussed. Because emission control is a big problem in day to day life. Aviation is most powerful and fastest growing field as well as transportation modes in the world. Global aviation contributes about 2.7% of global greenhouse gas emissions and supports 8.9% of the world economic process in terms of GDP. With this phenomenal growth for air trafficking by different national and international airliners, the total carbon space available for flying is being progressively diminished and the consequential emission levels are becoming alarming over passage of time. It is therefore essential to reduce the emission from the aircraft foe a better and greener aviation. A jet engine is a reaction engine, which generates thrust by jet propulsion in accordance with Newton's law of motion. Hence, the power produced by the engine is high and the emissions are greater than the considerable amount. Emissions generally refers to the greenhouse gases such as carbon monoxide, Nitrogen dioxides, hydrocarbons, carbon dioxide etc. various methods are developed to reduce the emission from aircrafts such as use of alternative bio-fuel and reducing fuel consumption. This project deals with emission control by reduction in fuel consumption as it is the most efficient and effective method. In this paper, turbofan engine is modelled and analyzed using ANSYS software. The result after analysis showed that increase in bypass ratio reduces the fuel consumption, thereby reducing the emission. [ABSTRACT FROM AUTHOR]

The present study focuses on the innovative technique for making rectangular and circular hollow concrete blocks using fly ash (FA) and recycled concrete aggregates (RCA). The feasibility of employing RCA in conjunction with fly ash as a substitute for natural aggregates and cement in a proportion ranging from 30%–90% and 15%–45%, respectively, is tested in the laboratory. According to current standards, the tests comprise the slump test, compressive strength test, water absorption test, and structural efficiency evaluation. An empirical quantitative technique is used for the cost–benefit analysis of a 100-square-foot model built with recycled concrete hollow blocks. The study suggests that employing recycled concrete aggregate and fly ash as replacements for conventional materials would result in a minimum cost savings of 17%. The quantity of greenhouse gases produced in CO2 equivalents during concrete production is calculated using the Inventory of Carbon and Energy database. According to research findings, the utilization of recycled concrete aggregates and fly ash reduced carbon dioxide equivalent emissions by 30%–40%. It was also confirmed that cement has a major effect on greenhouse gas emission generation throughout the concrete manufacturing phase, regardless of the use of RCA over virgin aggregates. This study intends providing a significant understanding of how RCA and FA can not only contribute to environmental conservation but also offer economic benefits. Finally, the research intends to encourage the adoption of ecologically responsible and economically viable sustainable practices in the construction industry. [ABSTRACT FROM AUTHOR]

Anthropogenic methane emissions are a leading cause of the increase in global average temperatures, often referred to as global warming. Flooded soils play a significant role in methane production, where the anaerobic conditions promote the production of methane by methanogenic microorganisms. Rice fields contribute a considerable portion of agricultural methane emissions, as rice plants provide both factors that enhance and limit methane production. Rice plants harbor both methane- producing and methane-oxidizing microorganisms. Exudates from rice roots provide source for methane production, while oxygen delivered from the root aerenchyma enhances methane oxidation. Studies have shown that the diversity of these microorganisms depends on rice cultivars with some genes characterized as harboring specific groups of microorganisms related to methane emissions. However, there is still a need for research to determine the balance between methane production and oxidation, as rice plants possess the ability to regulate net methane production. Various agronomical practices, such as fertilizer and water management, have been employed to mitigate methane emissions. Nevertheless, studies correlating agronomic and chemical management of methane with productivity are limited. Moreover, evidences for breeding low-methane-emitting rice varieties are scattered largely due to the absence of coordinated breeding programs. Research has indicated that phenotypic characteristics, such as root biomass, shoot architecture, and aerenchyma, are highly correlated with methane emissions. This review discusses available studies that involve the correlation between plant characteristics and methane emissions. It emphasizes the necessity and importance of breeding low-methane-emitting rice varieties in addition to existing agronomic, biological, and chemical practices. The review also delves into the ideal phenotypic and physiological characteristics of low-methane-emitting rice and potential breeding techniques, drawing from studies conducted with diverse varieties, mutants, and transgenic plants. [ABSTRACT FROM AUTHOR]

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Agricultural landscape management and climate seasonality can influence soil structure, hydraulic conductivity, and air permeability within the context of soil water and soil gas mobility. To investigate this, in situ and laboratory-based data were collected from three agricultural landscape positions within a watershed in eastern Ontario, Canada during a growing season. Macropore classification, water infiltration tests, and air permeability measurements were conducted in situ and standard soil characterizations were carried out on soil samples. Hydraulic conductivity of the soil matrix, based on grain size data, indicated that the highest values were consistently measured in the B horizon at each landscape setting. Macropores were found to be more abundant within uncultivated drainage ditch bank soils, compared to the adjacent cropped fields. Macropores in the ditch bank soils were exclusively consisted of circular biopores, while both circular and linear macropores were observed in the cultivated field soils. Air permeability, vertical hydraulic conductivity, and horizontal hydraulic conductivity were also greater in the uncultivated soils, relative to the cultivated soils. Field saturated hydraulic conductivity measurements offered evidence of anisotropy, likely due to the vertical nature of the macropore features. Macropore disposition and extent varied over the growing season, especially in the cultivated field soils where tillage and field trafficking are physically disruptive. Seasonality of macropore development will influence temporal changes in advection-based mass exchange of gas and water in the vadose zone. Modeling of mass exchange in agricultural soils should consider time variability in macroporosity to more realistically characterize infiltration and soil gas emissions. [ABSTRACT FROM AUTHOR]

We develop a novel and generic text-based measure to classify and evaluate greenhouse gas (GHG) disclosures. We construct the measure using collocation analysis of GHG-related words and regular expressions. Automated implementation achieved high concordance compared to manual investigations. We move beyond the "bag-of-words" approach in classifying voluminous nonfinancial corporate disclosure. We also outline a methodology that is manyfold scalable and makes replicability straightforward. Compared to past studies, we work with a significantly larger sample of 5,017 reports across 80 countries, thereby dealing with greater complexity and leading to better generalizability. We also contribute to the debate on whether nonfinancial disclosures exhibit accountability or are merely greenwashing. We find a negative trend in accountability worldwide, and firm-level accountability in GHG disclosures is not detectable in a country-level reduction of GHG emissions. Moreover, firms disclose significantly higher accountable information in a civil-law legal environment compared to those in a common-law legal environment. JEL Classifications: M14; M40. [ABSTRACT FROM AUTHOR]

Forest management, especially understory vegetation conversion, significantly affects soil greenhouse gas (GHG) emissions and soil C and N pools. However, it remains unclear what effect renovating understory vegetation has on GHG emissions and soil C and N pools in plantations. This study investigates the impact of renovating understory vegetation on these factors in Chinese hickory (Carya cathayensis Sarg) plantation forests. Different understory renovation modes were used in a 12-month field experiment: a safflower camellia (SC) (Camellia chekiangoleosa Hu) planting density of 600 plants ha−1 and wild rape (WR) (Brassica napus L.) strip sowing (UM1); SC 600 plants ha−1 and WR scatter sowing (UM2); SC 1200 plants ha−1 and WR strip sowing (UM3); SC 1200 plants ha−1 and WR scatter sowing (UM4); and removal of the understory vegetation layer (CK). The results showed that understory vegetation modification significantly increased soil CO2 and emission fluxes and decreased soil CH4 uptake fluxes (p < 0.01). The understory vegetation transformation significantly improved soil labile carbon and labile nitrogen pools (p < 0.01). This study proposes that understory vegetation conversion can bolster soil carbon sinks, preserve soil fertility, and advance sustainable development of Chinese hickory plantation forests. [ABSTRACT FROM AUTHOR]

With the continuous development of the global economy, carbon dioxide and other greenhouse gas emissions are persistently increasing, making global warming an indisputable fact. As a high-energy consuming industry, the building industry has gradually emerged as the primary source of greenhouse gas emissions during urban expansion. Consequently, countries are exploring sustainable development pathways for low-carbon buildings to minimize the detrimental impact caused by the construction industry. This paper summarizes the current status of low-carbon building development and, through literature analysis concerning carbon standard systems and carbon emission accountings, discusses the challenges and possible improvements for the future. Establishing a quantitative evaluation tool for carbon emissions and elucidating accounting methods in the construction field is fundamental and a prerequisite for comprehensively studying low-carbon buildings throughout their life cycle. The challenges of low-carbon building development are as follows: (1) lack of a set of carbon emission measurement standards that can be commonly used internationally, (2) lack of a deep and systematic study of the theory of carbon emission accountings and (3) difficulty in recognizing carbon emission boundaries and related data for existing carbon emission accounting methods. This paper provides a comprehensive analysis of the current progress in low-carbon building development, along with an examination and optimization of the application of carbon emission accounting methodologies within construction to address the challenges. [ABSTRACT FROM AUTHOR]

Climate change due to enhanced greenhouse effect arising as a result of human activities is considered a major global environmental threat to mankind. This study experimentally investigates and determines the heat flow in and out of the earth surface, and the impact of greenhouse effect on the heat transfer. A high voltage electric bulb was placed between two bottles; an empty bottle containing only air and the other bottle containing a mixture of baking soda and vinegar, evolving CO2. We observed that the vinegar and baking soda in the filled bottle reacted and produced carbon dioxide (CO2). This CO2 absorbs and retains more heat from the high voltage bulb than the empty bottle of normal air. We also observed that visible light passes through the glass and is absorbed by darker surfaces inside. The demonstration of this study proves that greenhouse gases like CO2 is one of major greenhouse gases that are responsible for global warming by trapping heat thereby giving a rapid rise in temperature over time because of the concomitant lower heat loss to its environment. [ABSTRACT FROM AUTHOR]

The steel industry in China, the world's largest, contributes to about 15% of the nation's total carbon emissions. Instead of direct combustion, the technology of converting off-gas from the steel industry into liquid fuels not only enhances the added value of this byproduct but also helps alleviate carbon emissions. This study, for the first time, integrates the specific circumstances of China to evaluate the carbon emissions of Ethanol to Jet (ETJ) and Fischer–Tropsch to Jet (FTJ) fuel technologies utilizing Basic Oxygen Furnace Gas (BOFG) and Coke Oven Gas (COG) as feedstocks. Six cases were examined using Aspen Plus (V11) for mass and energy balance: Case 1: BOFG/ETJ, Case 2: BOFG/FTJ, Case 3: COG/ETJ, Case 4: COG/FTJ, Case 5: (COG + BOFG)/ETJ, and Case 6: (COG + BOFG)/FTJ. The analysis underscores that the FTJ pathway exhibits superior carbon reduction efficiency relative to ETJ. Compared to traditional petroleum-based aviation fuels (86.65 g CO2eq/MJ), the FTJ pathways utilizing COG or COG + BOFG as feedstocks exhibit significant advantages in greenhouse gas (GHG) emission reductions, with carbon emissions of 23.60 g CO2eq/MJ and 41.48 g CO2eq/MJ, respectively, representing reductions of 72.76% and 52.13%. Furthermore, employing uncertainty analysis based on the Monte Carlo method establishes the credibility of the findings. Finally, sensitivity analysis for parameter optimization and process improvements demonstrates the significant impact of the life cycle assessment (LCA) allocation method on computational results for exhaust gas feedstocks. Given the limited coverage of lifecycle assessments for Ethanol to Jet and Fischer–Tropsch to Jet pathways in China, this study could assist policymakers in determining the development trajectory of sustainable aviation fuel (SAF) in China. [ABSTRACT FROM AUTHOR]

The construction industry, as a major consumer of resources and energy, accounts for about 40% of global carbon emissions. The concept of a circular economy (CE) is one effective means to address this issue. The entire lifecycle of a building includes: material production, construction, operation, and demolition. The production of building materials emits the largest proportion of carbon dioxide, followed by the operational phase, while construction (including demolition) has the smallest proportion. However, it is crucial to note the waste phase after demolition, where building materials are typically disposed of through incineration or landfill, leading to significant carbon emissions and environmental degradation. Therefore, carbon emissions generated during both the production and waste phases of the construction industry cannot be overlooked. This article employs a combined approach of practice and research, using the Circular Pavilion as a case study. From the design stage, reducing resource usage and carbon emissions are considered crucial factors. Reversible design, modularity, and the use of recycled materials are employed to reduce the emissions of "embodied carbon" and enhance material reuse. To validate the effectiveness of recycled materials in reducing greenhouse gas (GHG) emissions, this study calculates the material usage and carbon emissions during the production, transportation, and waste phases of the Circular Pavilion, Concrete Pavilion, and Steel Pavilion. The Circular Pavilion accounts for 34% and 3.5% of the total carbon emissions of the Concrete Pavilion and Steel Pavilion, respectively. In conclusion, the practical implementation of reversible design and recycled materials based on the concept of a circular economy is key to transitioning the construction industry from environmentally harmful impacts to eco-friendly practices. This establishes an effective method for resource reuse and carbon dioxide reduction in the construction sector, allowing waste resources to re-enter production and manufacturing processes, thereby reducing natural extraction, waste disposal, and energy consumption. Future applications of this method in the construction field involve establishing multidimensional composite design models and conducting feasibility assessments with upstream and downstream supply chains to support the realization of circular cities. [ABSTRACT FROM AUTHOR]

Sulfur hexafluoride (SF6), which survives in the atmosphere for an extremely long period of time, is the most potent greenhouse gas regulated under the Kyoto Protocol. So, the accurate monitoring of atmospheric SF6 plays an important role in the study of the control policies for reducing greenhouse gas emissions. The instruments for SF6 measurement are typically calibrated using certified reference materials. The concentrations of the commercially available SF6 reference materials usually have a broad range, from 1 μmol/mol to 6000 μmol/mol. Some characteristics including sensitivity, linear range, relative standard deviation, and accuracy are crucial for the determination of SF6 in such a broad concentration range. Therefore, the selection of a proper detector for the accurate determination of SF6 with such a broad range is extremely important to establish a gas chromatography (GC) method for developing SF6 reference materials. In this paper, several typical GC methods with different detectors, including a thermal conductivity detector (TCD), a pulsed discharge helium ionization detector (PDHID), and a flame photometric detector (FPD), were carefully established for the accurate determination of SF6 with different concentrations. The results show that an FPD detector has a relatively narrow linearity range, thus a quadratic equation should be established for building a calibration curve. The PDHID and TCD have good linearity with coefficients of 1.0000 in the concentration range of 10–100 μmol/mol (using a PDHID), and 100–1000 μmol/mol (using a TCD), respectively. Further considering the measurement errors of indication results, the PDHID is suitable for SF6 measurement when the concentrations are below 100 μmol/mol, whereas the TCD is suitable for SF6 measurement when the concentrations are over 100 μmol/mol. These results provide useful guidance in choosing an appropriate GC detector for the accurate determination of SF6, which are especially very helpful for developing SF6 reference materials. [ABSTRACT FROM AUTHOR]

Motivated by numerous lower atmosphere climate model hindcast simulations, we performed simulations of the Earth's atmosphere from the surface up through the thermosphere‐ionosphere to reveal for the first time the century scale changes in the upper atmosphere from the 1920s through the 2010s using the Whole Atmosphere Community Climate Model—eXtended (WACCM‐X v. 2.1). We impose solar minimum conditions to get a clear indication of the effects of the long‐term forcing from greenhouse gas increases and changes of the Earth's magnetic field and to avoid the requirement for careful removal of the 11‐year solar cycle as in some previous studies using observations and models. These previous studies have shown greenhouse gas effects in the upper atmosphere but what has been missing is the time evolution with actual greenhouse gas increases throughout the last century, including the period of less than 5% increase prior to the space age and the transition to the over 25% increase in the latter half of the 20th century. Neutral temperature, density, and ionosphere changes are close to those reported in previous studies. Also, we find high correlation between the continuous carbon dioxide rate of change over this past century and that of temperature in the thermosphere and the ionosphere, attributed to the shorter adjustment time of the upper atmosphere to greenhouse gas changes relative to the longer time in the lower atmosphere. Consequently, WACCM‐X future scenario projections can provide valuable insight in the entire atmosphere of future greenhouse gas effects and mitigation efforts. Plain Language Summary: From seeing lower atmosphere computer climate models run for the past century, we decided to do the same for the upper atmosphere using the Whole Atmosphere Community Climate Model‐eXtended (WACCM‐X) for the decades from the 1920s to 2010s. In this higher region, the atmosphere is affected strongly by the Sun and removing the Sun's effect is tricky in previous observation and model studies. We make the Sun's effect small to see only effects from the Earth's magnetic field and greenhouse gases. Earlier studies focused on recent decades show effects of greenhouse gas increases on the upper atmosphere but not for the early decades of the past century with greenhouse gas changes from less than 5% increase prior to the space age and the transition to the over 25% increase in the latter half of the 20th century. We cover this entire period and get results like those in studies before, with especially the temperature change matching very well with the greenhouse gas carbon dioxide change. Because WACCM‐X performs well over the past century, it will be useful to predict what will happen in the century ahead as greenhouse gases increase and humans make efforts to reverse the increase. Key Points: Whole Atmosphere Community Climate Model‐eXtended (WACCM‐X) simulated continuous rate of climate change in the thermosphere/ionosphere over the past century follows closely that of CO2 and CH4Large CO2/thermosphere temperature correlation shows greenhouse gas impact on upper atmosphere climate is consistent over the past centuryConsistency with past century observations and model simulations gives confidence in results of WACCM‐X 21st century climate projections [ABSTRACT FROM AUTHOR]

Life cycle assessment was used to study the following six major stages of animal husbandry: feed grain planting, feed grain transportation and processing, livestock and poultry breeding, livestock and poultry gastrointestinal fermentation, manure management, and livestock and poultry product slaughter and processing. The greenhouse gas emissions from animal husbandry in Shandong Province were quantified for the entire 20-year period spanning from 2002 to 2021. This study also analyzed the emission patterns and characteristics associated with this life cycle assessment. The results show that over the past 20 years, the greenhouse gas emissions from animal husbandry in Shandong Province increased continuously, the greenhouse gas emission intensity decreased continuously, and both of these trends tended to be stable. From a life cycle standpoint, the primary sources of greenhouse gas emissions were gastrointestinal fermentation and the management of livestock and poultry manure. In terms of the structure of livestock and poultry breeding, poultry was the primary source of greenhouse gas emissions. The emission characteristics of the greenhouse gases produced by animal husbandry varied among different cities in Shandong Province. The main source of greenhouse gas discharged due to animal husbandry in Zibo and Binzhou was Ecattle; in Dongying, it was Esheep; and in the remaining cities, it was mainly Epoultry. [ABSTRACT FROM AUTHOR]

Treating wastewater with low carbon-to-nitrogen (C/N) ratios by constructed wetlands (CWs) is still problematic. Adding chemicals is costly and may cause secondary pollution. Configuring plant diversity in substrate-based CWs has been found to be a better way to treat low-C/N wastewater, but wastewater treatment in floating CWs needs to be studied. In this study, wastewater with C/N ratios of 5 and 10 were set in simulated floating CWs, and 9 combinations with plant species richness (SR) of 1, 3, and 4 were configured. The results showed that (1) increasing SR improved the total N mass removal (NMR) by 29% at a C/N ratio of 5 but not 10; (2) the presence of Oenanthe javanica in the microcosms increased the NMR by 13% and 20% with C/N ratios of 5 and 10, respectively; (3) increasing SR mitigated the net global warming potential (GWP) by 120% at a C/N ratio of 5 but not 10; and (4) a Hemerocallis fulva × O. javanica × Echinodorus parviflours × Iris hybrids mixture resulted in a high NMR and low net GWP. In summary, assembling plant diversity in floating CWs is an efficient and clean measure during the treatment of wastewater with a C/N ratio of 5. [ABSTRACT FROM AUTHOR]

This study introduces a comprehensive analytical method for assessing refrigerant purity, offering various insights into accurate and precise estimations of greenhouse gas (GHG) emissions and the reclamation of refrigerants. Samples of three different states of CH 2 FCF 3 (R134a), namely recovered R134a, reclaimed R134a, and new R134a, were prepared and analyzed for all impurities. Non-condensable gases (O 2 , N 2 , CH 4 , CO, and H 2) were analyzed using gas chromatography (GC) with a thermal conductivity detector (TCD) and a pulsed discharge detector (PDD), and unidentified complex compound impurities containing C, H, Cl, and F were investigated using GC with mass spectrometry (MS) and an atomic emission detector (AED). The purities of the three samples were determined by calculating the total quantity of impurities and their uncertainties. The calculated values for the purities of recovered R134a, reclaimed R134a, and new R134a were 953,125.38 µmol/mol (1,272.45 µmol/mol, k = 2), 998,529.67 µmol/mol (31.58 µmol/mol, k = 2), and 998,803.56 µmol/mol (32.50 µmol/mol, k = 2), respectively. The majority of impurities detected were GHGs with high global warming potentials (GWPs) up to 11,200. Certain impurities were found at concentrations exceeding 1,000 µmol/mol. The annual GHG emissions resulting only from R134a impurities in South Korea were approximately 0.01 MtCO 2 eq. Because of the large number of GHGs in refrigerants, a comprehensive examination of refrigerant impurities is necessary for refrigerant monitoring and GHG inventory management. [ABSTRACT FROM AUTHOR]

Understanding the patterns of greenhouse gas emissions and the changes in pollution load in terrestrial freshwater systems is crucial for accurately assessing the global carbon cycle and overall greenhouse gas emissions. However, current research often focuses on wetlands and rivers, with few studies on agricultural drainage ditches, which are an important part of the agricultural ecosystem. Investigating the greenhouse gas emission patterns and pollution load changes in agricultural drainage ditches can help accurately assess the greenhouse effect of agricultural systems and improve fertilization measures in farmlands. This study explored the effects of nitrogen input and aeration on the pollution load and greenhouse gas emission processes in paddy field drainage ditches. The results showed that aeration significantly reduced the concentration of ammonium nitrogen (NH4+) in the water, decreased the emissions of nitrous oxide (N2O) and methane (CH4), and slightly increased the emission of carbon dioxide (CO2), resulting in an overall reduction of the global warming potential (GWP) by 34.02%. Nitrogen input significantly increased the concentration of ammonium nitrogen in the water, slightly reduced the emissions of N2O and CH4, and increased the CO2 emissions by 46.60%, thereby increasing the GWP by 15.24%. The drainage ditches reduced the pollution load in both the water and sediment, with the overall GWP downstream being 9.34% lower than upstream. [ABSTRACT FROM AUTHOR]

Enhancing movement options for confined dairy cows, like in tie-stall housing, may boost natural behaviour and welfare. Yet, limited data exists on the environmental impact of both indoor and outdoor exercise areas. This study investigates the impact of exercise pen type on effluent properties and gas emissions during winter and/or summer conditions in a northern country such as Canada. Forty-five Holstein dairy cows were randomly assigned to three treatments: (1) no exercise [cows kept indoors with tie-stalls (TSs)]; (2) indoor exercise [access to a 28 m2 cow−1 indoor pen (IP) for 1.5 h d−1] and (3) outdoor exercise [access to a 28 m2 cow−1 outside nonaerated (OnAP) or aerated stand-off pad (OAP) for 1.5 h d−1]. The effluent composition of OnAP and OAP varied notably between seasons. In winter, OAP leachates showed higher biological oxygen demand (+89 %), pH (+1.2 units), ammonium (+96 %) and total solids (+50 %), lower faecal but higher total coliforms (−120 % and +20 %, respectively) than OnAP during summer. In addition, OAP presented higher biological and chemical oxygen demand (+80 %) than OnAP in both seasons. Both OAP and OnAP showed higher carbon dioxide emissions (+150 %) and lower methane emissions during summer (−200 %) than IP and TS. Nitrous oxide emissions were higher for OnAP (+600 %) than in OAP, IP and TS, with no changes in ammonia emissions across treatments. Outdoor exercise for dairy cows using a filtering pen didn't meet environmental limits for removing leached contaminants. Exercise pens raised carbon dioxide and nitrous oxide emissions but decreased methane emissions. • Non-aerated, aerated pads served as seasonal exercise areas for tie-stall cows. • Efficient woodchip matrix filters pad leachates by removing contaminants. • Aeration failed to enhance leachate contaminant removal in the stand-off pad. • Outside exercise pens reduce greenhouse gas emissions from dairy housing surfaces. [ABSTRACT FROM AUTHOR]

Background: Mask induction of anesthesia for pediatric patients has included the use of nitrous oxide since the inception of pediatric anesthesia. However, the use of nitrous oxide precludes adequate preoxygenation. Additionally, pediatric physiology (less Functional Residual Capacity, higher oxygen consumption), increased risk of laryngospasm and lack of intravenous access increase the risk of a severe airway complication in the event of airway occlusion. Nitrous oxide does not facilitate tranquil mask placement on an unwilling child and does not meaningfully speed mask induction. Exposure to nitrous oxide has potential occupational health concerns and nitrous oxide has significant environmental detriment. Conclusion: Utilizing other, evidence‐based, techniques to facilitate tranquil mask placement will assure that patients have a pleasant induction experience and avoiding nitrous oxide will reduce the environmental impact, as well as improve the safety of, pediatric mask induction. [ABSTRACT FROM AUTHOR]

The latest progress and future development direction of algae granular sludge wastewater treatment and resource utilization process are reviewed・ The cultivation and formation mechanism of algae granular sludge were analyzed, and the key environmental factors affecting the process of algae granular sludge were analyzed from the aspects of light, temperature and stirring, and the advantages of the process in the context of carbon neutrality were introduced・ The development prospect of outdoor technology of algae granular sludge in the future and the related problems that may be faced are summarized. [ABSTRACT FROM AUTHOR]

Background: Liriope platyphylla and organic acids (humic and fulvic acids) as additives in the feedstock may aid in decreasing CH4 formation in the rumen. Based on previous studies, Hanwoo steers were raised with feedstock added with Liriope platyphylla and organic acids and their fecal samples were analyzed to determine the changes in their organic matter and nitrogen content determining the GHG emissions from feces in the form of CH4 and N2O. Methods: Ten Hanwoo cattle were provided with experimental diet and their weights were measured to determine harmful effects of experimental diet and measure fecal composition. To measure CH4 emission from the rumen in vitro, rumen fluid with Liriope platyphylla 1.0% and organic acids 0.05% added to the feed was prepared and incubated in triplicate. Result: The addition of Liriope platyphylla had a positive effect on immune function and blood composition, as well as CH4 reduction and further the addition of organic acids resulted in the lowering of CH4 emissions when compared with that of the control. The addition of Liriope platyphylla and organic acids is a potential additive of reducing CH4 emissions from ruminants without disrupting cattle growth. [ABSTRACT FROM AUTHOR]

The ever-increasing consumption of fossil fuels to meet up with the global economic and industrial energy needs has led to climatic change due to uncontrollable emission of a major greenhouse gas (CO2). As a way of mitigating the amount of CO2 in the atmosphere, search for effective and efficient solid adsorbent has been at the front burner of current scientific research. A class of solid adsorbent known as metal organic frameworks (MOFs) have demonstrated immense potentials for CO2 adsorption due to its porous, high thermal and chemical stability, high versatility and ease of production. Upon functionalization, the adsorption efficiency of this class of materials was found to improve tremendously. In this review, the CO2 capture and sequestration potentials of three MOFs (UiO-66, HKUST-1, and MOF-5) and their composites were investigated in the search for economical, stable, and highly selective novel adsorbents for CO2 adsorption. [ABSTRACT FROM AUTHOR]

Croplands account for ~ one‐third of global anthropogenic nitrous oxide (N2O) emissions. A number of recent field experiments found substantial fallow‐period N2O emissions, which have been neglected for decades. However, the global contribution of the fallow‐period emissions and the associated drivers remain unclear. Based on 360 observations across global agroecosystems, we simulated the ratio of the fallow to the whole‐year N2O emissions (Rfallow) by developing a mixed‐effect model and compiling cropping‐system‐specific input data. Our results revealed that the mean global gridded Rfallow was 44% (15%–75%, 95% confidence interval), with hotspots mainly in the northern high latitudes. For most cropping systems, soil pH was the dominant driver of global variation in Rfallow. Global cropland emission factors (i.e., the percentage of fertilizer N emitted as N2O, EFs) in EF‐based models doubled to 1.9% when the fallow‐period N2O emissions were included in our simulation, similar to EFs estimated by process‐based and atmospheric inversion models (1.8%–2.3%). Overall, our study highlights the importance of fallow‐period N2O emissions in annual totals, especially for single cropping systems and croplands in acidic areas. To accurately estimate N2O emissions for national greenhouse gas inventories, it is crucial to update current EFs with full consideration of the fallow‐period N2O emissions in the Intergovernmental Panel on Climate Change (IPCC) Tier 1 method. [ABSTRACT FROM AUTHOR]

Terrestrial ecosystems are increasingly being exposed to metallic nanoparticles (MNPs). However, the global‐scale impact of MNPs on soil carbon dioxide (CO2) emission remains unknown, limiting our understanding of the role of MNPs in global carbon cycle. We compiled a dataset comprising 1764 pairs of experimental observations to investigate the effects of MNPs exposure on soil respiration parameters, including respiration rates, related enzyme activities, and microbial variables. We found that MNPs could stimulate or suppress soil basal respiration rates across global environments, depending largely on the type of MNPs. We further showed that, although the inhibition of MNPs on most enzyme activities peaked in short‐term exposure (≤28 days), prolonged exposure to MNPs still inhibited soil organic carbon degradation. Finally, we determined that environmental conditions (e.g., soil pH and presence/absence of plants) were also important regulators of the influence of MNPs on soil respiration parameters. Our findings underline that the effects of MNPs on soil CO2 emission depended on MNPs type, exposure design, and environmental factors, which is critical for predicting the role of MNPs in influencing the global carbon cycle and climate change. [ABSTRACT FROM AUTHOR]

Organic carbon decomposition in lake sediments contributes substantially to the global carbon cycle and is strongly affected by temperature. However, the magnitude of temperature sensitivity (Q10) of decomposition and the underlying factors remain unclear at the continental scale. Carbon quality temperature (CQT) hypothesis asserts that less reactive and more recalcitrant molecules tend to have higher temperature sensitivities, but its support is challenged by complex composition of organic matter and environmental constraints. Here, we quantified Q10 of the sediments across 50 freshwater ecosystems along a 3500 km north–south transect, and characterized the quality of sediment dissolved organic carbon with chemodiversity reflected in molecular richness, functional traits (i.e., molecular weight, bioavailability, etc.) and composition. We further included classic environmental variables, such as climatic, physicochemical and microbial factors, to explore how Q10 is constrained by these factors or carbon quality. We found that Q10 varied greatly across lakes, with the mean value of 1.78 ± 0.62, but showed nonsignificant latitudinal pattern. Q10 was primarily predicted by chemodiversity and showed an increasing trend with the biochemical recalcitrance indicated by traits such as aromaticity and standard Gibb's Free Energy at both molecular and compositional levels. This suggests that carbon quality is the crucial determinant of Q10 in lakes, supporting the CQT hypothesis. Moreover, Q10 decreased linearly with the increase of molecular richness, implying that the resistance of decomposition to warming is associated with higher molecular diversity. Compared with the structural equation model containing only environmental variables, inclusion of chemodiversity increased 32.8% of the explained variation in Q10, and chemodiversity was the only driver showing direct effects. Collectively, this study illustrates the importance of chemodiversity in shaping the pattern of Q10, and has significant implications for accurately predicting the carbon turnover in lake ecosystems in the context of global warming. [ABSTRACT FROM AUTHOR]

The increasing levels of carbon dioxide (CO2) in our atmosphere demand innovative and efficient methods for its reduction. In this context, we present an advanced solar‐driven photocatalyst, Pt‐doped graphitic carbon nitride (Pt/g‐C3N4), specifically engineered for enhanced photoreduction of CO2. Our findings highlight the dual advantage of Pt/g‐C3N4: enhanced visible light absorption and electron‐hole pair dynamics, ensuring efficient carrier separation. Notably, the CO and CH4 yields, when employing Pt/g‐C3N4, surpassed those with the pristine g‐C3N4 catalyst by factors of 3.1 and 4.3, respectively. Moreover, the Pt/g‐C3N4 catalyst exhibited consistent high‐efficiency of CO2 conversion over successive cycles, emphasizing the catalyst's robustness. This work underscores the potential of Pt/g‐C3N4 as a viable tool against escalating CO2 levels, paving the way for a green and sustainable conversion of this predominant greenhouse gas into beneficial chemicals. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Sugarcane is an important crop for tropical countries and to accurately inventory its greenhouse gas (GHG) emissions baseline measurements are needed. In Colombia, sugarcane is one of the most important crops in terms of cultivated area and, paradoxically, scientific information reporting GHG emissions based on field measurements is almost nonexistent. The objective of this work was to quantify the direct emissions of carbon dioxide (CO2) and nitrous oxide (N2O) in the sugarcane-soil system of the Cauca river valley, Colombia. For this purpose, a field experiment was established in a typic haplustert soil cropped with sugarcane. The effects of nitrogen (N) fertilization and sampling site on its GHG emissions were tested using the closed static chamber method over a period of 211 days. The main cumulative emissions were 765.14 ± 34.1 g CO2–C m−2 and 125.4 ± 22.6 mg N2O–N m−2. Overall, GHG emissions were modified by N fertilization, the sampling site, and their interaction. Nitrogen fertilization with urea increased mean and cumulative CO2 and N2O emissions, especially at the row sampling site. This paper highlights the importance of considering these factors when the quantification of GHGs or a reduction of their associated uncertainties are required. This work reportss the first GHG emissions data for a typical sugarcane agroecosystem in Colombia. [ABSTRACT FROM AUTHOR]

East Asia (China, Japan, Koreas, and Mongolia) has been the world's economic engine over at least the past two decades, exhibiting a rapid increase in fossil fuel emissions of greenhouse gases (GHGs) and has expressed the recent ambition to achieve climate neutrality by mid‐century. However, the GHG balance of its terrestrial ecosystems remains poorly constrained. Here, we present a synthesis of the three most important long‐lived greenhouse gases (CO2, CH4, and N2O) budgets over East Asia during the decades of 2000s and 2010s, following a dual constraint approach. We estimate that terrestrial ecosystems in East Asia is close to neutrality of GHGs, with a magnitude of between −46.3 ± 505.9 Tg CO2eq yr−1 (the top‐down approach) and −36.1 ± 207.1 Tg CO2eq yr−1 (the bottom‐up approach) during 2000–2019. This net GHG sink includes a large land CO2 sink (−1229.3 ± 430.9 Tg CO2 yr−1 based on the top‐down approach and −1353.8 ± 158.5 Tg CO2 yr−1 based on the bottom‐up approach) being offset by biogenic CH4 and N2O emissions, predominantly coming from the agricultural sectors. Emerging data sources and modeling capacities have helped achieve agreement between the top‐down and bottom‐up approaches, but sizable uncertainties remain in several flux terms. For example, the reported CO2 flux from land use and land cover change varies from a net source of more than 300 Tg CO2 yr−1 to a net sink of ∼−700 Tg CO2 yr−1. Although terrestrial ecosystems over East Asia is close to GHG neutral currently, curbing agricultural GHG emissions and additional afforestation and forest managements have the potential to transform the terrestrial ecosystems into a net GHG sink, which would help in realizing East Asian countries' ambitions to achieve climate neutrality. Plain Language Summary: East Asia (China, Japan, Koreas and Mongolia) is not only the hotspot of anthropogenic greenhouse gas (GHG, including CO2, CH4 and N2O) emissions, but also a region with large CO2 sink. However, the greenhouse gas balance of greenhouse gases over the region is poorly understood. In this study, we performed a synthesis for over 40 flux terms to provide the first‐of‐its‐kind GHG budget assessment over the decades of 2000s and 2010s. We find terrestrial ecosystems in East Asia is close to neutrality of GHGs. The bottom‐up approach summing up component fluxes estimated a net balance of −36.1 ± 207.1 Tg CO2eq yr−1, while the top‐down approach based on atmospheric inversions estimated a net balance of −46.3 ± 505.9 Tg CO2eq yr−1. This results from compensation of the large CO2 sink by CH4 and N2O emissions, and from compensation of net GHG sink over natural ecosystems by net GHG source over agricultural ecosystems. Thus, curbing agricultural GHG emissions has the potential to realizing the ambitious goal of achieving climate neutrality over East Asia. Key Points: A comprehensive greenhouse gas (CO2, CH4 and N2O) accounting including about 40 flux terms over East Asia is reportedTerrestrial ecosystems in East Asia are close to greenhouse gas neutralNatural ecosystems is a net greenhouse gas sink, compensated by a net source from agricultural ecosystems [ABSTRACT FROM AUTHOR]

As the largest energy-consuming province in China, Shandong faces the dual task of greenhouse gas (GHG) reduction and atmospheric pollution control. Based on the latest activity data and updated emission factors, this study establishes a high-resolution emission inventory (5 km × 5 km) for GHGs and main atmospheric pollutants from the energy consumption sectors of Shandong Province from 2010 to 2021, quantifies the relationship between social economic factors and GHGs and atmospheric pollutants emissions using the expanded stochastic environmental impact assessment (STIRPAT) model, and forecasts the future emission trend with the help of the scenario analysis method. Results indicate that the electricity and transportation sectors are the main contributors to all pollutants. Spatially, the high value of pollutants is mainly concentrated in the urban agglomerations of central and eastern Shandong. Up to 72% of GHGs and 50% of air pollution emissions are attributed to the top 10% of emission grids. Emission peaks occur mainly in summer and winter due to straw burning, increased utilization of temperature-controlled facilities, and expansion of plant capacity. Population, energy consumption, the proportion of secondary industry, and energy consumption intensity are the most significant influencing factors for pollutant emissions. Scenario analysis results indicate Shandong province can reach its carbon peak in 2027 without sacrificing population growth or economic progress. [ABSTRACT FROM AUTHOR]

This study builds on the expanding literature on the interplay of corporate governance and corporate environment behaviour following the introduction of the carbon reporting directives of the UK Companies Act in 2013. We specifically focus on seeking clarity on the relationship between gender diversity, board independence, and board size with corporate environmental performance. The study examines these relationships under a mandatory nonfinancial reporting (NFR) requirement and tests the impact of regulatory shocks on board composition and channels affecting carbon emission. The findings confirm that board gender diversity and independence improve a firm's environmental performance. And while larger board sizes lead to larger environmental investments, the study finds that larger board sizes leads to poor environmental performance for the firm. The findings contribute to developments in countries, such as the United States, where there is an ongoing debate on the adoption of a mandatory NFR of carbon and the response of corporate boards. [ABSTRACT FROM AUTHOR]

Low- and middle-income countries (LMICs) are rapidly urbanizing, leading to a high demand for high-quality animal products. Production increase is seen as a key to meeting this demand and reducing the global environmental impact of low-yielding dairy production system (DPS) often found in LMICs. Therefore, the present study assesses the relationship between enteric methane emissions and different dairy production strategies, taking DPS in the rural-urban interface of Bengaluru, an Indian megacity, as a case study. Twentyeight dairy farms, evenly distributed across four DPS, were monitored for 1 year (eight visits at 6-week intervals). Following IPCC 2006 guidelines and a Tier 2 approach, enteric methane emissions from dairy cattle were calculated as carbon dioxide equivalents (CO2 eq). Dairy producers in ExtDPS, an extensive DPS found throughout the rural-urban interface of Bengaluru, fed their dairy cattle a high-quality diet, partly based on organic wastes from markets or neighbors, achieving 9.4 kg energy-corrected milk (ECM) per cow and day. Dairy producers in Semi-ADPS, a semi-intensive and rural DPS, fed an average quality diet and achieved the lowest milk production (7.9 kg ECM cow-1 day-1; p < 0.05). Dairy producers in Semi-BDPS, another semi-intensive and rural DPS, relied on average quality but more abundant feedstuffs and achieved a production of 10.0 kg ECM cow-1 day-1. A similar milk yield (10.1 kg ECM cow-1 day-1) was achieved by IntDPS, an intensive and rural DPS. The intensity of enteric methane emissions was the highest in Semi-BDPS (1.38 kg CO2-eq kg-1 ECM; p < 0.05), lowest in ExtDPS (0.79 kg CO2-eq kg-1 ECM; p < 0.05), and intermediate in semi-ADPS and IntDPS. The results highlight the close relationship between the intensity of enteric methane emissions and the intensification strategies chosen by dairy producers based on locally available resources. They also underline the importance of region- and system-specific environmental assessments of production systems in LMICs. [ABSTRACT FROM AUTHOR]

Composting manure is one of the most important ways to treat livestock manure in China. Large-scale breeding is an ever-increasing high demand for animal products, particularly with the rapid development of animal husbandry. A large number of discharged livestock manure has posed a serious risk to environmental protection. Composting has been widely used as an efficient technology for the resource utilization of manure. But there is some CO2, CH4, N2O and NH3 emission in the period of composting.Thelossofmaterialnutrientscanreducethefertilizerefficiencyofcompostproducts, leading to secondary pollution and the global greenhouse effect. The current treatment of cattle manure cannot fully meet the large-scale production, duetothesimplecompostinginthelow-scaleofbeefcattlefarms.Thisstudyaimstoexploretheemissionregularityand greenhouseeffectofdifferentcompostingtreatmentsongreenhousegasesandammonia.A71dexperimentwasalso conducted on cattle manure composting in the Miyun District of Beijing, China. Cattle manure and corn stalks were selected as the raw materials. Four treatments were set (static composting, T1; composting + turning, T2; composting + film mulching, T3; turning + film mulching, T4). The results showed that the highest temperatures of T1, T2, T3 and T4 were 67.70℃, 70.13℃, 63.12℃, and67.18℃, respectively, while the duration of high-temperature period (>55℃) was11, 11, 4and13days, respectively. The initial moisture content of the four experimental groups was 70.01%, indicating a downward trend on the whole, especiallyinthehigh-temperatureperiod.Onthe14thday, the moisture contents of each treatment decreased by 30.92%, 29.25%, 35.94%, and 35.94% respectively. In the middle period of composting, the moisture contents of T1 and T4 treatments rebounded and increased, but they were still decreasing on the whole. At the later stage of composting, the moisture contents of each treatment were 29.66%, 15.63%, 37.05% and 41.38%, respectively, with decrease rates of 57.63%, 77.67%, 47.08%, and40.89%, respectively.Thegerminationindexesofthefourtreatmentswere131.33%, 134.49%, 108.76%, and 136.24%, respectively, which all met the maturity requirements of compost products (≥70%).The turning promoted the temperature rise of the pile from the index of temperature and maturity. Both T2 and T4 treatments showed that the secondary temperature rose on the second day of turning. The heat preservation of the pile was improved by covering it with plastic film. All four treatments had rapidly raised the temperature for the high temperature to kill the harmful bacteria, thus making the pile harmless. The tipping point was beneficial to the emission of CO2, N2O and NH3, according to the gas emission. The plastic film mulching also inhibited the generation of N2O. The warming potentials of the four treatments were 23 573.33, 25 048.34, 18 826.63, and 24 680.09 g/(d·m²), respectively, at the end of composting. The warming potential of the T3 treatment was the lowest, whiletheemissionreductionratewas20.14%, compared with the T1treatment.Therefore, T3treatmentcanbe expected to effectively reduce the warming potential to the maturity of compost products. This finding can provide technical guidance to optimize the practice selection of composting in small and medium-sized farms. [ABSTRACT FROM AUTHOR]

Anthropogenic nutrient input stimulates surface eutrophication and algal blooms and thus exacerbates oxygen depletion and hypoxia in aquatic ecosystems. However, existing studies have paid little attention on the understanding of the feedback relationships among oxygen consumption, algal succession and greenhouse gas effect after river damming, particularly in Three Gorges Reservoir. This field work investigated the thermal stratification, water quality and phytoplankton in four tributaries (Pengxi Bay (PXB), Daning Bay (DNB), Shennong Bay (SNB), and Xiangxi Bay (XXB)) of the Three Gorges Reservoir (TGR) in spring (April 25-28, 2022), and explored the drivers of hypoxia and its feedback response to algal blooms and methane (CH4) emissions. The results showed that during the observation period, DO, thermal stratification, and algal blooms were more severe in PXB. The high Chemical Oxygen Demand (CODMn) (11.27 mg•L-1) and Dissolved Organic Carbon (DOC) content (7.56 mg•L-1) in PXB were the main causes of the progressive hypoxia. Furthermore, stronger density stratification in PXB inhibited the vertical supply of DO and accelerated bottom hypoxia. But the downslope density current replenished bottom DO in the upper reaches of the DNB, SNB, and XXB. The CH4 concentration was generally higher in hypoxia zone, especially in where cyanobacteria are the dominant species (eg., PX03 and PX04). Dam construction led to the succession of algal-dominant species, exerting a significant influence on the river carbon cycle. The expansion of cyanobacterial blooms and the consequence of metabolic substrates increase are gradually increasing oxygen deprivation, even hypoxia, and enhancing CH4 production in rivers. These findings suggest that the succession of algal-dominant species caused by river damming has a pronounced positive feedback effect on reservoir hypoxia processes and greenhouse effect. [ABSTRACT FROM AUTHOR]

The January 2022 eruption of the Hunga Tonga‐Hunga Ha'apai underwater volcano injected a large amount of water vapor into the mid‐stratosphere. This study uses model simulations to investigate the resulting stratospheric impacts out to 2031. Maximum radiatively‐driven model temperature changes occur in the Southern Hemisphere (SH) subtropics in April–May 2022, with warming of ∼1 K in the lower stratosphere and cooling of 3 K in the mid‐stratosphere. The radiative cooling combined with adiabatic cooling driven by the quasi‐biennial oscillation meridional circulation explains the near‐record cold anomaly observed in the SH subtropical mid‐stratosphere. Projected ozone responses maximize in 2023–2024 as the water vapor plume is transported globally throughout the stratosphere and mesosphere. The excess H2O increases the OH radical, causing a negative global ozone response (2%–10%) in the upper stratosphere and mesosphere due to increased odd hydrogen‐ozone loss, and a small positive ozone response (0.5%–1%) in the mid‐stratosphere due to interference of the NOx catalytic loss cycle by the additional OH. In the lower stratosphere, the excess H2O is projected to increase polar stratospheric clouds and springtime halogen‐ozone loss, enhancing the Antarctic ozone hole by 25–30 DU in 2023. Arctic impact is small, with maximum additional ozone loss of 4–5 DU projected in spring 2024. These responses diminish after 2024 to be quite small by 2031, as the excess H2O is removed from the stratosphere with a 2.5‐year e‐folding time. Given the year‐to‐year variability of the stratosphere, the magnitudes of these ozone responses may be below the threshold of detectability in observations. Plain Language Summary: Stratospheric ozone protects Earth's biosphere from harmful ultraviolet radiation, and along with water vapor, are key components in determining temperature and chemistry of the atmosphere. The January 2022 eruption of the Hunga Tonga‐Hunga Ha'apai underwater volcano in the South Pacific injected water vapor into the atmosphere, increasing stratospheric water vapor by 10%. In this study, we use computer simulations of the stratosphere to project how this additional water vapor changed temperature and ozone in the months and years following the eruption. The water vapor cooled the middle stratosphere (roughly 14–25 miles above Earth's surface) and warmed the lower stratosphere (6–14 miles above the surface), with the largest changes of 2–5° Fahrenheit in March–June 2022, several months after the eruption. The additional water vapor modified chemical processes that affect stratospheric ozone, leading to a projected 10%–15% enhancement in the Antarctic ozone hole. This ozone hole enhancement is estimated to have maximized in October 2023, almost 2 years after the eruption, due to the slow circulation of stratospheric water vapor from the subtropics to the polar region. These impacts are expected to diminish after 2024 as the excess water vapor is slowly removed from the atmosphere by natural processes. Key Points: The water vapor injection from the Hunga Tonga eruption impacts stratospheric temperature and ozoneLargest additional ozone depletion is estimated to occur in Antarctic spring 2023. The ozone response may not be detectable in observationsThe impacts are projected to gradually diminish after 2024 as the excess water vapor is removed from the stratosphere [ABSTRACT FROM AUTHOR]