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1.
Sci Rep ; 14(1): 23389, 2024 Oct 08.
Article in English | MEDLINE | ID: mdl-39379398

ABSTRACT

Globally, aquatic ecosystems are one of the largest but most uncertain sources of methane, a potent greenhouse gas. It is unclear how climate change will affect methane emissions, but recent work suggests that glacial systems, which are melting faster with climate change, may be an important source of methane to the atmosphere. Currently, studies quantifying glacial emissions are limited in number, and the role of methanotrophy, or microbial methane oxidizers, in reducing atmospheric emissions from source and receiving waters is not well known. Here we discuss three potential sites for methane oxidation that could mitigate emissions from glaciers into the atmosphere: under ice oxidation, oxidation within proglacial lakes, and oxidation within melt rivers. The research presented here increases the number of glacial sites with methane concentration data and is one of only a few studies to quantify the net microbial activity of methane production and oxidation in two types of land-terminating glacial runoff (lake and river). We find that oxidation in a glacial river may reduce atmospheric methane emissions from glacial melt by as much as 53%. Incorporating methane oxidation in estimates of glacial methane emissions may significantly reduce the estimated magnitude of this source in budgeting exercises.

2.
ChemSusChem ; : e202400931, 2024 Sep 23.
Article in English | MEDLINE | ID: mdl-39312754

ABSTRACT

This review highlights the use of CO2 as a reagent in hydrometallurgy, with emphasis on the new concept of circular hydrometallurgy. It is shown how waste CO2 can be utilised in hydrometallurgical operations for pH control or regeneration of acids for leaching. Metal-rich raffinate solutions generated after removal of the valuable metals can serve as feedstocks for mineral carbonation, providing alternative avenues for CO2 sequestration. Furthermore, CO2 can also be used as a renewable feedstock for the production of chemical reagents that can find applications in hydrometallurgy as lixiviant, as precipitation reagent or for pH control. Mineral carbonation can be combined with chemical reactions involving metal complexation reagents, as well as with solvent extraction processes for the concurrent precipitation of metal carbonates and acid regeneration. An outlook for future research in the area is also presented.

3.
Intern Med J ; 2024 Sep 21.
Article in English | MEDLINE | ID: mdl-39305104

ABSTRACT

COP-28, the United Nations' Climate Change Conference, hosted by the United Arab Emirates, ended on 12 December 2023. At the convention, Australia released its National Health and Climate Strategy, committing to low-carbon, climate-responsive care. The Strategy will need new policies, projects and investments and a fit-for-purpose health workforce. This is a tall order considering healthcare's challenges. Everyone has a role, including clinicians, healthcare agencies, policymakers, politicians, patients and the providers and manufacturers in the supply chain. Clinicians' groups, policymakers and federal and state departments of health have an opportunity to lead climate change reform by considering climate change impacts across clinical practice and health policy.

4.
Bioresour Technol ; 413: 131446, 2024 Sep 05.
Article in English | MEDLINE | ID: mdl-39241814

ABSTRACT

Cordycepin, a nucleoside analog, is widely used in medicine and health products. However, the production of cordycepin from Cordyceps militaris faces the challenges of low productivity and high rate of greenhouse gas emissions. In this study, by optimizing the cordycepin biosynthesis pathway through promoter combination, Kozak sequence, and enzyme fusion, enhancing the methanol assimilation capacity in peroxisomes, adjusting the synthesis of NADPH and ATP, and combining the enhanced supply of adenosine and 3'-AMP, the cordycepin high-yield strain Pp29 was constructed, which produced 1551.44 mg/L cordycepin by shake-flask fermentation. In fed-batch fermentation, Pp29 achieved the highest yield (8.11 g/L, 67.64 mg/g DCW, and 1.35 g/L/d) to date in 10 L fermenter, and the CO2-eq emissions were 1.9-17.3 times lower than C. militaris and other yeast systems. This study provide basis for Pichia pastoris to be used as chassis cell for synthesizing cordycepin and other nucleoside analogs by methanol as carbon source.

5.
Front Nutr ; 11: 1438369, 2024.
Article in English | MEDLINE | ID: mdl-39246405

ABSTRACT

Introduction: Sustainable foods need to be nutrient-rich, affordable, environmentally friendly, and socially acceptable. Pulses, which include beans, lentils, chickpeas, and dried peas are a food group that can fit all those criteria. Methods: These concepts were tested serially using nutrient profiling methods that focused on protein and were extended to include food prices, greenhouse gas emissions, and energy demand. The present sustainability analyses were based on the US Department of Agriculture (USDA) nutrient composition and food prices data. Environmental impact data came from life cycle assessments (LCA). First, the USDA Protein Foods Group was disaggregated into animal and plant proteins. Plant proteins were separated into pulses, soy products, and nuts and seeds. Results: Pulses were among the lowest-cost protein sources (per 100 g and per 100 kcal) and had the lowest greenhouse gas emissions GHGE and energy demand. Pulses were among the most sustainable foods when monetary and energy costs were expressed per 50 g of protein (equivalent to 100% DV). Pulses scored well on the Nutrient Rich Food (NRF9.3) nutrient profiling system and on the related Affordable Nutrition Index that assessed nutrient density per penny. Discussion: Pulses are a source of low-cost plant-based protein and a variety of priority vitamins and minerals, have low carbon footprint and energy demand, and are a valued culinary ingredient across diverse regions and cultures. As dietary guidance turns to plant-based diets, pulses need to be integrated into the global sustainability framework.

6.
Heliyon ; 10(16): e35759, 2024 Aug 30.
Article in English | MEDLINE | ID: mdl-39247308

ABSTRACT

Rice-shrimp rotation systems are one of the widespread farming practices in the Vietnamese Mekong Delta coastal areas. However, greenhouse gas (GHG) emissions in the system have remained unclear. This study aimed to examine methane (CH4) and nitrous oxide (N2O) emissions from the system, including (i) land-based versus high-density polyethylene-lined (HDPE) nursery ponds and (ii) conventional versus improved grow-out ponds inoculated with effective microorganisms (EM) bioproducts. The results showed that CH4 flux in land-based and HDPE-lined nursery ponds were 1.04 and 0.25 mgCH4 m-2 h-1, respectively, while the N2O flux was 8.37 and 6.62 µgN2O m-2 h-1, respectively. Global warming potential (GWP) from land-based nursery ponds (18.3 g CO2eq m-2) was approximately 3 folds higher than that of the HDPE-lined nursery pond (6.1 g CO2eq m-2). Similarly, the mean CH4 and N2O fluxes were 15.84 mg CH4 m-2 h-1 and 7.17 µg N2O m-2 h-1 for the conventional ponds, and 10.51 mg CH4 m-2 h-1 and 7.72 µg N2O m-2 h-1 for the improved grow-out ponds. Conventional practices (2388 g CO2eq m-2) had a higher 1.5-fold GWP compared to the improved grow-out pond (1635 g CO2eq m-2). The continuation of the land-based nursery pond and conventional aquacultural farming practices increase CH4 emission and GWP, while applying HDPE-lined nursery ponds combined with improved grow-out ponds could be a promising approach for reducing GHG emissions in rice-shrimp rotation systems. This study recommends further works in the rice-shrimp rotation systems, including (i) an examination of the effects of remaining rice stubbles in the platform on the availability of TOC levels and GHG emissions and (ii) ameliorating dissolved oxygen (DO) concentration on the effectiveness of GHG emission reduction.

7.
Trop Life Sci Res ; 35(1): 139-160, 2024 Mar.
Article in English | MEDLINE | ID: mdl-39262860

ABSTRACT

A large-scale rubber plantation in Southern Thailand is expected to capture a significant amount of carbon dioxide from emissions through carbon sinks in the vegetation and soil. The goal of this research is to create a carbon offset assessment for rubber plantations lasting for 30 years using a voluntary market contract approach. To evaluate the area of large-scale rubber plantations, this study evaluated major growing regions in five provinces in the middle-south region of Thailand (Nakhon Si Thammarat, Phatthalung, Songkhla, Satun and Trang) using an integrated RS-GIS technique that incorporated biomass allometric equations, soil series databases, and object-based classification. The classification of rubber plantation areas and the mapping of rubber stand ages were conducted to estimate the above-ground biomass of the rubber tree. Texture analysis was used in the rubber classification process, and normalised difference vegetation index (NDVI) was combined with texture analysis to separate vegetation areas from other land cover. Four groups of varying ages (1-6, 7-13, 14-20 and 21-30 years old) were evaluated for their capacity to generate carbon offsets. The equations of voluntary market contract revenue according to the contract method of the CCX were applied for this case study. This evaluation was used to estimate their annual value, total and net incomes in the carbon market price regarding the RGGI Allowance (RGA). Carbon offset income was then used to estimate the potential income (over a 30-year period) of the life of the contract. The results showed that the carbon stock potential of rubber plantations depended on the age of the trees and the soil carbon stock. The total carbon stock in the rubber plantations varied from 249.73 to 301.48 Mg C/ha (or equivalently 916.49 to 1,106.44 Mg CO2e/ha). Furthermore, the potential net income of the contract was estimated to be between USD5,378.32 and USD5,930.38 Mg CO2e/ha over a 30-year period according to the voluntary market contract revenue. These results suggest that the large agricultural land plot policy could create opportunities for carbon offsetting. The policy of large-scale rubber areas could be used as a tool and mechanism for farmers who are considering participating in carbon-crediting mechanisms. Then, farmers could use voluntary market contracts as a guide and foundation for their decision-making. The carbon offset credit strategy could assist Thailand in achieving its climate goals of transitioning to a low-carbon agriculture sector.

8.
J Environ Manage ; 370: 122476, 2024 Sep 13.
Article in English | MEDLINE | ID: mdl-39276657

ABSTRACT

The intricate encapsulation structure and material composition of photovoltaic modules necessitate full materials recycling involving multiple stages and different technological configurations, thereby increasing environmental burden of recycling process. Consequently, environmental impact assessments are imperative. However, previous studies primarily focused on a single technology or compared different technologies within a specific recycling stage, overlooking various technological configurations and thus engendering incomprehensive assessment. Hence, we employ a comparative life-cycle assessment to evaluate the environmental performance of six recycling alternatives with different technological configurations for silicon photovoltaic waste in China, which encompasses five recycling stages and glass/silicon remanufacturing processes. Results shows thermal delamination reduces the normalized environmental impact by 8.73% and 4.62% compared with mechanical and chemical delamination, respectively; electrolysis for metals extraction carries 35.72%-36.35% higher environmental benefits than precipitation. Additionally, introducing silicon/glass remanufacturing provides an additional 6.27%-11.55% environmental benefits. Therefore, integrating disassembly, thermal delamination, leaching & etching, electrolysis, and remanufacturing exhibits the best environmental performance, with -4796 kg CO2-eq/tonne carbon emission and -46400 MJ/tonne energy demand. Environmental hotspots analysis identifies key contributors to environmental impact and benefits. Further sensitivity analysis highlights the importance of enhancing silver and copper recovery efficiency. Finally, targeted strategies are proposed for green recycling routes of photovoltaic waste.

9.
Plants (Basel) ; 13(17)2024 Aug 28.
Article in English | MEDLINE | ID: mdl-39273883

ABSTRACT

Agroecological ecosystems produce significant carbon dioxide fluxes; however, the equilibrium of their carbon sequestration, as well as emission rates, faces considerable uncertainties. Therefore, sustainable cropping practices represent a unique opportunity for carbon sequestration, compensating greenhouse gas emissions. In this research, we evaluated the short-term effect of different management practices in alleys (tillage, no tillage, alley cropping with Rosmarinus officinalis and Thymus hyemalis on soil properties, carbon sequestration, and CO2 emissions in a grapefruit orchard under semiarid climate). For two years every four months, soil sampling campaigns were performed, soil CO2 emissions were measured, and rhizosphere soils were sampled at the end of the experimental period. The results show that alley cropping with Thymus and Rosmarinus contributed to improve soil fertility, increasing soil organic carbon (SOC), total nitrogen, cation exchange capacity, and nutrients. The CO2 emission rates followed the soil temperature/moisture pattern. Tillage did not contribute to higher overall CO2 emissions, and there were no decreased SOC contents. In contrast, alley crops increased CO2 emission rates, especially Rosmarinus; however, the bigger root system and biomass of Rosmarinus contributed to soil carbon sequestration at a greater rate than Thymus. Therefore, Rosmarinus is positioned as a better option than Thymus to be used as an alley crop, although long-term monitoring is required to evaluate if the reported short-term benefits are maintained over time.

10.
Plants (Basel) ; 13(17)2024 Sep 06.
Article in English | MEDLINE | ID: mdl-39273988

ABSTRACT

Returning straw to the field is a crucial practice for enhancing soil quality and increasing efficient use of secondary crop products. However, maize straw has a higher carbon-to-nitrogen ratio compared to other crops. This can result in crop nitrogen loss when the straw is returned to the field. Therefore, it is crucial to explore how different methods of straw return affect maize (Zea mays L.) farmland. In this study, a field experiment was performed with three treatments (I, no straw returned, CK; II, direct straw return, SR; and III, straw returned in deep furrows, ISR) to explore the effects of the different straw return modes on soil carbon and nitrogen content and greenhouse gas emissions. The results indicated that the SR and ISR treatments increased the dissolved organic carbon (DOC) content in the topsoil (0-15 cm). Additionally, the ISR treatment boosted the contents of total nitrogen (TN), nitrate nitrogen (NO3--N), ammonium nitrogen (NH4+-N), dissolved organic nitrogen (DON), and DOC in the subsurface soil (15-30 cm) compared with CK. When it comes to greenhouse gas emissions, the ISR treatment led to an increase in CO2 emissions. However, SR and ISR reduced N2O emissions, with ISR showing a more pronounced reduction. The ISR treatment significantly increased leaf and grain biomass compared to CK and SR. The correlation analyses showed that the yield was positively correlated with soil DOC, and soil greenhouse gas emission was correlated with soil NO3--N. The ISR technology has great potential in sequestering soil organic matter, improving soil fertility, and realizing sustainable agricultural development.

11.
Environ Evid ; 13(1): 10, 2024 Apr 12.
Article in English | MEDLINE | ID: mdl-39294837

ABSTRACT

BACKGROUND: The global food system is inflicting substantial environmental harm, necessitating a shift towards more environmentally sustainable food consumption practices. Policy interventions, for example, information campaigns, taxes and subsidies and changes in the choice context are essential to stimulate sustainable change, but their effectiveness in achieving environmental goals remains inadequately understood. Existing literature lacks a comprehensive synthesis of evidence on the role of public policies in promoting sustainable food consumption. Our systematic map addressed this gap by collecting and categorising research evidence on public policy interventions aimed at establishing environmentally sustainable food consumption patterns, in order to answer the primary research question: What evidence exists on the effects of public policy interventions for achieving environmentally sustainable food consumption? METHODS: Searches for relevant records (in English) were performed in WoS, Scopus, ASSIA, ProQuest Dissertation and Theses, EconLit, Google Scholar and in bibliographies of relevant reviews. A grey literature search was also performed on 28 specialist websites (searches were made in the original language of the webpages and publications in English, Swedish, Danish and Norwegian were eligible) and Google Scholar (search in English). Screening was performed at title/abstract and full-text levels, with machine learning-aided priority screening at title/abstract level. Eligibility criteria encompassed settings, interventions (public policies on sustainable food consumption), target groups and outcomes. No critical appraisal of study validity was conducted. Data coding covered bibliographic details, study characteristics, intervention types and outcomes. Evidence was categorised into intervention types and subcategories. Visual representation utilised bar plots, diagrams, heatmaps and an evidence atlas. This produced a comprehensive overview of effects of public policy interventions on sustainable food consumption patterns. REVIEW FINDINGS: The evidence base included 227 articles (267 interventions), with 92% of studies in high-income countries and only 4% in low-income countries. Quantitative studies dominated (83%), followed by mixed methods (16%) and qualitative studies (1%). Most interventions were information-based and 50% of reviewed studies looked at labels. Information campaigns/education interventions constituted 10% of the sample, and menu design changes and restriction/editing of choice context 8% each. Market-based interventions represented 13% of total interventions, of which two-thirds were taxes. Administrative interventions were rare (< 1%). Proxies for environmental impact (85%) were more frequent outcome measures than direct impacts (15%). Animal-source food consumption was commonly used (19%) for effects of interventions on, for example, greenhouse gas emissions. Most studies used stated preferences (61%) to evaluate interventions. CONCLUSIONS: The literature assessing policies for sustainable food consumption is dominated by studies on non-intrusive policy instruments; labels, information campaigns, menu design changes and editing choice contexts. There is a strong need for research on sustainable food policies to leave the lab and enter the real world, which will require support and cooperation of public and private sector stakeholders. Impact evaluations of large-scale interventions require scaling-up of available research funding and stronger multidisciplinary research, including collaborations with industry and other societal actors. Future research in this field should also go beyond the European and North American context, to obtain evidence on how to counteract increasing environmental pressures from food consumption worldwide.

12.
Environ Sci Pollut Res Int ; 31(43): 55720-55735, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39243329

ABSTRACT

The increase in the negative effects of global change promotes the search for alternatives to supply the demand for food worldwide aligned with the Sustainable Development Goals (SDGs) to ensure food security. Animal protein, which is a main source of nutrients in the diet of today's society, especially beef, which is one of the most demanded products nowadays, has been criticized not only for its high water consumption and land occupation for production but also for the emission of greenhouse gases (GHG) from enteric methane generated in the fermentation process within the bovine rumen and deforestation for the adaptation of pastures. This study is mainly motivated by the lack of quantifiable scientific information in Colombia on the environmental impacts of beef production. Therefore, it is intended to estimate some of the impacts of beef production in extensive systems using the life cycle assessment (LCA) method under a particular scenario considering all the production phases (from raw material to fattening, where the cattle are ready to be slaughtered). The study was conducted with data supplied by a farm in Antioquia, Colombia, and the functional unit (FU) was defined as 1 kg of live weight (LW). The scope of this study was gate-to-gate. "The 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories" (IPCC  2006; IPCC 2019) was used to calculate methane and nitrous oxide emissions. LCA modeling was developed with Ecoinvent database v3.8 and the Umberto LCA + software. It was found that the most affected category of damage was ecosystem quality, which represents 77% of the total, followed by human health at 17% and resources at 6%. The category impact of agricultural land occupation is the one that represents the most significant contribution to the ecosystem quality endpoint, with a percentage of 87%, due to the soil's compaction and the loss of the soil's properties. Additionally, the obtained carbon footprint for the system was 28.9 kg of CO2-eq/kg LW.


Subject(s)
Greenhouse Gases , Colombia , Cattle , Animals , Greenhouse Gases/analysis , Environment , Methane
13.
Animal ; 18(9): 101294, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39226780

ABSTRACT

Rearing of replacement heifers makes up a significant part of the total costs in dairy farming. Nevertheless, the average age at first calving for dairy heifers still stays well above 2 years in many countries. This study examined the economic and environmental impacts of increased heifer growth rates and reduced replacement rates on Norwegian dairy farms. The current average growth rate in Norway (baseline scenario) was compared to an accelerated growth rate scenario. Within each of the two growth rate scenarios, we compared three different cow replacement rates. A farm account survey dataset containing physical and economic data on 311 Norwegian farms was clustered into three farm groups: small, medium, and large. To model economic consequences, we used the whole-farm linear programming model ScotFarm. A life cycle analysis model was used to model the environmental impacts of the baseline scenario and an accelerated growth rate scenario on the three farm groups. Accelerated heifer growth rate had a positive effect (14-28%) on farm annual gross margin depending on farm size. While accelerated growth rate resulted in only minor reductions in total emissions at farm level compared to the baseline scenario, reduced replacement rate lowered total farm level emissions by up to 8%, and emissions per unit of output by up to 6%. We conclude that an accelerated heifer growth rate scenario could potentially increase farm gross margin by some 14-28% compared with a baseline growth rate scenario. Reducing the replacement rate would be more efficient to reduce farm-level greenhouse gas emissions.


Subject(s)
Dairying , Farms , Greenhouse Gases , Animals , Cattle/growth & development , Female , Dairying/methods , Dairying/economics , Greenhouse Gases/analysis , Norway , Animal Husbandry/methods , Animal Husbandry/economics
14.
Sci Total Environ ; 953: 176069, 2024 Nov 25.
Article in English | MEDLINE | ID: mdl-39244066

ABSTRACT

Eutrophic shallow lakes are hotspots of carbon (C) and nitrogen (N) accumulation and transformation, and are increasingly recognized as important sources of greenhouse gases (GHGs: CO2, CH4 and N2O). Lacustrine groundwater discharge (LGD) is a crucial component of the water budget and terrestrial material delivery for lakes, but its interplays with intrinsic CN biogeochemical processes remain less tackled. In this study, C and N ingredients and multiple stable isotopes (δ2H, δ18O, δ13C, and δ15N) were measured seasonally in groundwater, river water and lake water of a large eutrophic shallow lake in eastern China. The results revealed that groundwater is enriched with various forms of C and N that have similar sources and pathways as surface water in the lake and rivers. The isotope balance model also indicated that LGD derived C and N contribute significantly to lake inventories in addition to river runoff. These allochthonous C and N provide extra substrates for related biogeochemical processes, such as algae proliferation, organic matter degradation, methanogenesis and denitrification. Simultaneously, the excess oxygen consumption leads to depletion and hypoxia in the lake, further facilitating the processes of methanogenesis and denitrification. LGD functions not only as an external source of C and N that directly increases GHG saturations, but also as a mediator of internal CN pathways, which significantly affect hypoxia formation, GHG productions and emissions in the eutrophic lake. This study highlights the unrevealed potential regulation of LGD on biogeochemical processes in the eutrophic lake, and underscores the need for its consideration in environmental and ecological studies of lakes both regionally and globally.

15.
J Hazard Mater ; 480: 135958, 2024 Sep 25.
Article in English | MEDLINE | ID: mdl-39342860

ABSTRACT

Although the increasing accumulation of microplastics (MPs) in terrestrial soil ecosystems has aroused worldwide concern, research remains limited on their potential impacts on soil processes and ecosystem functionality. Here, through a 41-day microcosm experiment, we found that polylactic acid (PLA), low-density polyethylene (LDPE), and polypropylene (PP) MPs consistently increased soil carbon nutrients and pH but had varying effects on soil nitrogen nutrients and the chemodiversity of dissolved organic matter (DOM). Different treatments led to notable shifts in the α-diversity and composition of soil microbial community, with phyla Proteobacteria and Ascomycota consistently enriched by MPs regardless of polymer type. The emissions of CO2 and N2O were suppressed by MPs in most cases, which in combination led to a decline in global warming potential. LDPE and 1 - 1.5 % of PLA MPs significantly improved the multifunctionality of the soil ecosystem, while PP and 0.5 % of PLA MPs exerted an opposite effect. Soil total organic carbon, pH, DOM molecular mass and condensation degree, and CO2 emissions were identified as the most important variables for predicting soil ecosystem multifunctionality. Results of this study can extend the current understanding of the impacts of MPs on soil biogeochemical cycling and ecosystem functionality.

16.
J Dairy Sci ; 2024 Sep 27.
Article in English | MEDLINE | ID: mdl-39343233

ABSTRACT

The objective of this study was to evaluate the GreenFeed (GF) and respiration chambers (RC) for daily and intraday measurements of the enteric gaseous exchange, as well as the metabolic heat production, lying behavior, and feed intake (FI) rate of dairy cows at these 2 respective housing conditions [tie-stall barn (TS) vs. RC] during the summer periods. Sixteen multiparous lactating dairy cows were recruited and arranged in a randomized complete block design with a baseline period established for each cow. Cows were given a basal diet (CON) for a baseline period of 7 d and were then fed a 3-nitrooxypropanol (3-NOP)-containing feed for the subsequent 26 d as experimental period. During both the baseline and the last 7 d of treatment period, gaseous exchanges of each animal were measured in the TS using GF for 8 6-hourly staggered measurements over 3 d, immediately followed by the measurement in RC for 2 d. Corresponding DMI, milk yield, and behavior parameters (e.g., lying behavior and FI rate) in TS and RC were recorded. The correlation coefficients of CH4 and H2 using raw data were 0.84 and 0.85, respectively. For all gases, correlation coefficients between GF and RC on individual cow level decreased when the marginal fixed effects (e.g., inhibitor and breed) were corrected by a mixed model. There were no differences in daily CH4 production or intensity between GF and RC (442 vs. 443 g CH4/d or 16.6 vs. 16.2 g CH4 /kg MY). However, greater CH4 yield was measured by GF than RC (19.0 vs. 17.8 g CH4/kg DMI), driven by a lower DMI (23.3 vs. 24.6 kg/d) when cows were housed in TS sampled by GF compared with cows being housed and sampled in RC. The correlations for CO2 production and O2 consumption were moderate and expected due to the variation associated with the mild heat stress condition during GF measurements in the TS (Thermal humidity index (THI) 56 vs. 68), as indicated by the reduced lying time (-2.1 h/d). At the intraday level, there was an interaction between techniques and hour-of-day for CH4 production, as indicated by the discrepancies in post-prandial CH4 emissions between techniques. In summary, this set of results showed that there were strong positive correlations for CH4 and H2 emissions between GF and RC based on individual cow data. However, such relationship should be interpreted with caution, given the data clustering resulting from the use of inhibitor 3-NOP. On treatment level, these 2 techniques detected similar inhibitor effect on the estimated daily CH4 emissions. The intraday patterns of CH4 and H2 production captured by GF provided a close approximation for those measured by RC. Nevertheless, potential underestimation may occur, especially following fresh feed delivery. For measuring CO2 production and O2 consumption, the GF captured similar intraday variations to those in the RC. However, the estimated daily production and consumption were not directly comparable, which was expected due to the variable thermal conditions during the summer. Further evaluations under the same weather conditions are warranted.

17.
J Environ Manage ; 370: 122613, 2024 Sep 25.
Article in English | MEDLINE | ID: mdl-39326084

ABSTRACT

Unlike the previous literature on climate change, this study employed the panel vector autoregressive model to examine the impact of population growth, governance quality, and economic growth on global warming. Moreover, we used the impulse response function tool, which was developed in the same context, to better understand the reaction of the main variables of interest, per capita greenhouse gas (GHG) emissions, aftershocks on population change, governance quality, and economic growth variables. Finally, the analysis was completed by the variance decomposition of all variables. These analyses were conducted for the 33 most polluting countries in terms of GHG from 1996 to 2019. The results show that both population growth and economic growth have a positive and significant influence on climate change and can strongly explain the gradual rise in Earth's temperature. Our empirical results show that there is a negative and significant relationship between the quality of governance and GHG emissions. The results show that there is a bidirectional causality between GHG emissions, population and economic growth. Based on the findings, this study proposes several policy recommendations.

18.
Environ Int ; 192: 109028, 2024 Sep 21.
Article in English | MEDLINE | ID: mdl-39307007

ABSTRACT

The use of biochar to reduce the gas emissions from paddy soils is a promising approach. However, the manner in which biochar and soil microbial communities interact to affect CO2, CH4, and N2O emissions is not clearly understood, particularly when compared with other amendments. In this study, high-throughput sequencing, soil metabolomics, and quantitative real-time PCR were utilized to compare the effects of biochar (BC) and organic manure (OM) on soil microbial community structure, metabolomic profiles and functional genes, and ultimately CO2, CH4, and N2O emissions. Results indicated that BC and OM had opposite effects on soil CO2 and N2O emissions, with BC resulting in lower emissions and OM resulting in higher emissions, whereas BC, OM, and their combined amendments increased cumulative CH4 emissions by 19.5 %, 31.6 %, and 49.1 %, respectively. BC amendment increased the abundance of methanogens (Methanobacterium and Methanocella) and denitrifying bacteria (Anaerolinea and Gemmatimonas), resulting in an increase in the abundance of mcrA, amoA, amoB, and nosZ genes and the secretion of a flavonoid (chrysosplenetin), which caused the generation of CH4 and the reduction of N2O to N2, thereby accelerating CH4 emissions while reducing N2O emissions. Simultaneously, OM amendment increased the abundance of the methanogen Caldicoprobacter and denitrifying Acinetobacter, resulting in increased abundance of mcrA, amoA, amoB, nirK, and nirS genes and the catabolism of carbohydrates [maltotriose, D-(+)-melezitose, D-(+)-cellobiose, and maltotetraose], thereby enhancing CH4 and N2O emissions. Moreover, puerarin produced by Bacillus metabolism may contribute to the reduction in CO2 emissions by BC amendment, but increase in CO2 emissions by OM amendment. These findings reveal how BC and OM affect greenhouse gas emissions by modulating soil microbial communities, functional genes, and metabolomic profiles.

19.
Environ Monit Assess ; 196(9): 851, 2024 Aug 27.
Article in English | MEDLINE | ID: mdl-39192147

ABSTRACT

Nighttime lighting (NTL), population growth, and climate change are critical concerns for Turkey. The intensity of nighttime lights in Turkey has significantly increased in recent years, closely associated with rapid population growth and urban expansion. Areas with higher population density exhibit greater nighttime light presence. Nighttime lighting is directly linked to energy consumption and greenhouse gas (GHG) emissions, contributing significantly to global climate change. The rise in nighttime lighting in Turkey exacerbates climate change effects. In this study, data on NTL were gathered from the NOAA/V21 satellite for 2013-2021, the NOAA/CMCFG satellite for average DMSP-OLS radiance values from 2013 to 2023, and the NOAA/VNP46A2 satellite for BRDF-corrected DMSP-OLS NTL data from 2013 to 2023. Night temperature values were extracted from NOAA and MODIS images, and their correlation with NTL data was analyzed. A moderate relationship was observed between NTL and night land surface temperature (LST) (R, 0.32; p-value < 0.05). Population and greenhouse gas emission data were sourced from the Turkish Statistical Institute (TurkStat). Carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated gases (F-gases) are direct greenhouse gases. A strong correlation was found between NTL and greenhouse gases (R, 0.8; p-value < 0.05). Population density emerges as a significant determinant of nighttime light intensity. These findings underscore the substantial correlation between nighttime light intensity in Turkey, population dynamics, and GHG emissions. The study suggests that NTL data can inform the development of sustainable environmental policies. Mitigating greenhouse gas emissions necessitates controlling population growth and energy consumption, pivotal steps toward environmental sustainability.


Subject(s)
Climate Change , Environmental Monitoring , Greenhouse Gases , Lighting , Turkey , Greenhouse Gases/analysis , Air Pollutants/analysis , Carbon Dioxide/analysis , Methane/analysis , Air Pollution/statistics & numerical data , Nitrous Oxide/analysis
20.
J Environ Manage ; 368: 122139, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39146653

ABSTRACT

Rice cultivation boasts a rich historical legacy, serving as the primary sustenance for over 50% of the global population. However, the cultivation process gives rise to the emission of methane (CH4) and nitrous oxide (N2O), two potent greenhouse gases. Notably, the global warming potential (GWP) of CH4 and N2O surpasses CO2 by 27-30 times and 273 times over 100 years, respectively. Addressing this environmental challenge necessitates exploring technical approaches and management strategies to curb gas emissions while sustaining rice yields. Several critical factors have been identified and analyzed for their potential to mitigate greenhouse gas production during rice cultivation. These include water management, fertilizer management, biochar application, cultivar selection, straw management, modified planting methods, and integration of new energy machinery. A comprehensive understanding and implementation of these methods can contribute significantly to achieving a dual objective: reducing emissions and maintaining optimal rice yields. Looking ahead, a synergistic integration of these diverse methods and management approaches holds promise for more effective results. Furthermore, the intricate water networks associated with rice cultivation should be carefully considered in the overall strategy. By adopting a holistic approach that addresses both emission reduction and sustainable water usage, the future of rice cultivation can be shaped to align with environmental stewardship and food security.


Subject(s)
Agriculture , Global Warming , Greenhouse Gases , Methane , Oryza , Oryza/growth & development , Oryza/metabolism , Methane/metabolism , Methane/biosynthesis , Agriculture/methods , Nitrous Oxide/metabolism , Nitrous Oxide/analysis , Fertilizers
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